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WO2023145712A1 - Liquid dispersion, light absorption layer, photoelectric conversion element, and solar cell - Google Patents

Liquid dispersion, light absorption layer, photoelectric conversion element, and solar cell Download PDF

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Publication number
WO2023145712A1
WO2023145712A1 PCT/JP2023/002035 JP2023002035W WO2023145712A1 WO 2023145712 A1 WO2023145712 A1 WO 2023145712A1 JP 2023002035 W JP2023002035 W JP 2023002035W WO 2023145712 A1 WO2023145712 A1 WO 2023145712A1
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dispersion
acid
less
organic compound
quantum dots
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PCT/JP2023/002035
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French (fr)
Japanese (ja)
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和弘 内原
明徳 小此木
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花王株式会社
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/30—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
    • H10K30/35—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains comprising inorganic nanostructures, e.g. CdSe nanoparticles
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/40—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising a p-i-n structure, e.g. having a perovskite absorber between p-type and n-type charge transport layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/50—Photovoltaic [PV] devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/30—Coordination compounds
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/50—Organic perovskites; Hybrid organic-inorganic perovskites [HOIP], e.g. CH3NH3PbI3

Definitions

  • the present invention relates to a dispersion for forming a light absorption layer, a light absorption layer obtained from the dispersion, a photoelectric conversion element having the light absorption layer, and a solar cell having the photoelectric conversion element.
  • Photoelectric conversion elements that convert light energy into electrical energy are used in solar cells, light sensors, copiers, etc.
  • photoelectric conversion elements solar cells that utilize sunlight, which is inexhaustible clean energy, have attracted attention.
  • Non-Patent Document 1 a quantum dot solar cell using PbS quantum dots surface-treated with a perovskite compound (CH 3 NH 3 PbI 3 ) as a light absorption layer has been reported (Non-Patent Document 1). ).
  • the amount of perovskite compound is small, and the perovskite compound hardly contributes to power generation, resulting in insufficient conversion efficiency.
  • a light absorption layer for forming a photoelectric conversion element and a solar cell with high conversion efficiency capable of photoelectric conversion in both the visible light region and the near-infrared light region comprising a perovskite compound, a halogen element and an organic and a quantum dot containing a ligand, and a light absorption layer in which the molar ratio of the organic ligand to the metal element constituting the quantum dot is 0.01 or more and 0.4 or less
  • the present invention provides a highly stable dispersion that is resistant to aggregation and precipitation even when a perovskite compound and/or its precursor and quantum dots are contained at a high concentration, a light-absorbing layer obtained from the dispersion, and the light-absorbing layer. and a solar cell having the photoelectric conversion element.
  • the present inventor adds an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof to a dispersion liquid containing a perovskite compound and/or its precursor and quantum dots having a ligand.
  • the present invention provides a dispersion and formulation containing a perovskite compound and/or its precursor, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof. It relates to a dispersion liquid formed by
  • the present invention also relates to a light absorbing layer containing a perovskite compound, a quantum dot having a ligand, and a hydrochloride of an organic compound having an amino group and a carboxy group.
  • the dispersion of the present invention contains or contains an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof, it is excellent in dispersibility and dispersion stability of quantum dots in the dispersion, and perovskite Even when the compound and/or its precursor and quantum dots are contained at a high concentration, aggregation and precipitation are unlikely to occur, and the stability over time is excellent. Therefore, by using the dispersion of the present invention, it is possible to increase the contents of the perovskite compound and the quantum dots in the light absorption layer, thereby improving the photoelectric conversion efficiency of the solar cell.
  • the dispersion of the present invention contains or blends a perovskite compound and/or precursor thereof, quantum dots having ligands, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof. It becomes The excellent dispersibility and dispersion stability of the quantum dots of the dispersion of the present invention is that the organic compound having an amino group and a carboxy group and / or a hydrochloride thereof is an intermolecular amino group and a carboxy group. It is presumed that due to the interaction of , they are loosely bound, form a string, and exist around the quantum dots, increasing the dispersion stability of the quantum dots.
  • the perovskite compound is not particularly limited, but from the viewpoint of improving the photoelectric conversion efficiency, it is preferably one or more selected from compounds represented by the following general formula (1) and compounds represented by the following general formula (2). and more preferably a compound represented by the following general formula (1).
  • RMX 3 (1) (Wherein, R is a monovalent cation, M is a divalent metal cation, and X is a halogen anion.)
  • the R is a monovalent cation, for example, a cation of a Group 1 element of the periodic table and an organic cation, preferably an organic cation from the viewpoint of improving the photoelectric conversion efficiency.
  • cations of Group 1 elements of the periodic table include Li + , Na + , K + , and Cs + .
  • organic cations include an ammonium ion which may have a substituent and a phosphonium ion which may have a substituent.
  • R 1 , R 2 and R 3 is independently a monovalent cation, and any or all of R 1 , R 2 and R 3 may be the same.
  • Examples include cations of Group 1 elements of the periodic table and organic cations.
  • Examples of cations of Group 1 elements of the periodic table include Li + , Na + , K + , and Cs + .
  • Examples of organic cations include an ammonium ion which may have a substituent and a phosphonium ion which may have a substituent.
  • the n is an integer of 1 or more and 10 or less, and preferably 1 or more and 4 or less from the viewpoint of improving durability and photoelectric conversion efficiency.
  • M is a divalent metal cation such as Pb 2+ , Sn 2+ , Hg 2+ , Cd 2+ , Zn 2+ , Mn 2+ , Cu 2+ , Ni 2+ , Fe 2+ , Co 2+ , Pd 2+ , Ge 2+ , Y 2+ and Eu 2+ and the like. From the viewpoint of excellent durability (humidity resistance) and photoelectric conversion efficiency, M is preferably Pb 2+ , Sn 2+ or Ge 2+ , more preferably Pb 2+ or Sn 2+ , still more preferably Pb 2+ . is.
  • X is a halogen anion, such as a fluorine anion, a chlorine anion, a bromine anion, and an iodine anion.
  • X is preferably a fluorine anion, a chloride anion, or a bromine anion, more preferably a chloride anion, or a bromine anion, still more preferably a bromine anion, in order to obtain a perovskite compound having a desired bandgap energy. is.
  • the perovskite compound preferably has a bandgap energy of 1.5 eV or more and 4.0 eV or less.
  • the perovskite compound may be of one type alone, or two or more types having different bandgap energies.
  • the bandgap energy of the perovskite compound is preferably 1.7 eV or more, more preferably 2.0 eV or more, still more preferably 2.1 eV or more, still more preferably 2.2 eV, from the viewpoint of improving the photoelectric conversion efficiency (voltage). From the viewpoint of improving the photoelectric conversion efficiency (current), it is preferably 3.6 eV or less, more preferably 3.0 eV or less, and even more preferably 2.4 eV or less.
  • the bandgap energies of the perovskite compound and the quantum dots can be obtained from absorption spectra measured at 25° C. by the method described in Examples below. The wavelength corresponding to the bandgap energy determined from the absorption spectrum is called the absorption edge wavelength.
  • Examples of compounds represented by the general formula (2) having a band gap energy of 1.5 eV or more and 4.0 eV or less include (C 4 H 9 NH 3 ) 2 PbI 4 and (C 6 H 13 NH 3 ).
  • the perovskite compound can be produced, for example, from a perovskite compound precursor.
  • perovskite compound precursors include, when the perovskite compound is the compound represented by the general formula (1), a combination of a compound represented by MX2 and a compound represented by RX. Further, when the perovskite compound is a compound represented by the general formula (2), the compound represented by MX 2 , the compound represented by R 1 X, the compound represented by R 2 X, and any R A combination with one or more selected from compounds represented by 3X can be mentioned.
  • the quantum dots are inorganic nanoparticles having a crystal structure with a particle size of about 20 nm or less, and exhibit physical properties different from those of the perovskite compound due to the quantum size effect.
  • the quantum dot known ones can be used without any particular limitation. It is preferable to use a compound having a bandgap energy less than that of the perovskite compound.
  • a quantum dot may be used individually by 1 type, and may use together 2 or more types from which bandgap energy differs.
  • the upper limit of the bandgap energy of the quantum dots ie, "the bandgap energy less than the bandgap energy of the perovskite compound” means two or more perovskite compounds. is a bandgap energy that is less than the maximum bandgap energy possessed by .
  • preferred aspects of quantum dots are preferred aspects common to the light absorbing layer and its raw material.
  • the bandgap energy of the quantum dots is preferably 0.6 eV or more, more preferably 0.7 eV or more, and still more preferably 0.8 eV or more. current), it is preferably 1.6 eV or less, more preferably 1.5 eV or less, even more preferably 1.4 eV or less, still more preferably 1.3 eV or less.
  • the particle size and type of quantum dots are determined by electron microscope observation, electron beam diffraction, X-ray diffraction pattern, etc.
  • the correlation between particle size and bandgap energy eg, ACS Nano, 2014 , 8, 6363-6371
  • the bandgap energy can also be calculated.
  • the difference between the bandgap energy of the perovskite compound and the bandgap energy of the quantum dots is preferably 0.4 eV or more, more preferably 0.8 eV or more, and still more preferably 1.0 eV or more, from the viewpoint of improving photoelectric conversion efficiency. , more preferably 1.2 eV or more, preferably 2.8 eV or less, more preferably 2.0 eV or less, still more preferably 1.6 eV or less, still more preferably 1.4 eV or less.
  • the particle size of the quantum dots is not particularly limited as long as it exhibits a quantum effect, but from the viewpoint of improving dispersibility, structural stability and photoelectric conversion efficiency, it is preferably 1 nm or more, more preferably. is 2 nm or more, more preferably 3 nm or more, preferably 20 nm or less, more preferably 10 nm or less, and still more preferably 5 nm or less.
  • the particle size of the quantum dots can be measured by conventional methods such as XRD (X-ray diffraction) crystallite size analysis and transmission electron microscope observation.
  • quantum dots having the bandgap energy include metal oxides, metal chalcogenides (e.g., sulfides, selenides, tellurides, etc.), and specific examples include PbS, PbSe, PbTe, CdS, CdSe, CdTe, Sb2S3 , Bi2S3 , Ag2S , Ag2Se , Ag2Te, Au2S , Au2Se , Au2Te , Cu2S, Cu2Se , Cu2Te , Fe2S , Fe2Se , Fe2Te , In2S3 , SnS, SnSe, SnTe, CuInS2 , CuInSe2 , CuInTe2 , EuS, EuSe , and EuTe.
  • the quantum dots preferably contain a Pb element, more preferably PbS or PbSe, and still more preferably
  • the quantum dots have ligands from the viewpoint of dispersibility in the light absorption layer and dispersion liquid, ease of production, cost, and excellent performance.
  • the ligand is not particularly limited, and may be, for example, one or more selected from organic compounds and halogen-containing substances, and may be both organic compounds and halogen-containing substances. From the viewpoint of improving the photoelectric conversion efficiency, it preferably contains a halogen-containing substance.
  • Examples of the organic compound that is a ligand include a carboxy group-containing compound, an amino group-containing compound, a compound containing a carboxy group and an amino group, a thiol group-containing compound, and phosphino group-containing compounds, and the like.
  • carboxy group-containing compounds examples include oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid.
  • the carboxy group-containing compound excludes compounds containing a carboxy group and an amino group.
  • amino group-containing compounds examples include oleylamine, stearylamine, palmitylamine, myristylamine, laurylamine, caprylamine, octylamine, hexylamine, and butylamine.
  • Amino group-containing compounds exclude compounds containing a carboxy group and an amino group.
  • Compounds containing a carboxy group and an amino group include, for example, aliphatic amino acids, and the aliphatic amino acids may be straight-chain amino acids or branched-chain amino acids.
  • the term "linear amino acid” refers to an aliphatic amino acid having a linear carbon chain structure
  • the term “branched chain amino acid” refers to an aliphatic amino acid having a branched carbon chain structure.
  • the number of carbon atoms in the aliphatic amino acid is selected from the viewpoint of improving the carrier transfer rate in the light absorption layer to improve the photoelectric conversion efficiency, and from the viewpoint of reducing the distance between the quantum dots so that the quantum dots are arranged in the matrix of the perovskite compound. From the viewpoint of high-density dispersion, it is preferably 10 or less, more preferably 8 or less, and still more preferably 7 or less, and from the viewpoint of ensuring dispersibility in the dispersion, preferably 2 or more, more preferably 3 or more. be.
  • the amino group of the aliphatic amino acid may be bonded to any carbon in the carbon chain, but the aliphatic amino acid can be easily coordinated to the surface of the quantum dot, and the From the viewpoint of improving the dispersibility of the quantum dots, it is preferably bonded to primary carbon.
  • thiol group-containing compounds examples include ethanethiol, ethanedithiol, benzenethiol, benzenedithiol, decanethiol, decanedithiol, and mercaptopropionic acid.
  • phosphino group-containing compounds examples include trioctylphosphine and tributylphosphine.
  • the organic ligand is preferably a carboxy group-containing compound, an amino group-containing compound, or a combination of a carboxy group and an amino group, from the viewpoint of ease of production of quantum dots, dispersibility, versatility, cost, and excellent performance expression.
  • containing compound more preferably a carboxy group-containing compound or an amino group-containing compound, more preferably a carboxylic acid, more preferably a fatty acid, still more preferably a fatty acid having 8 to 30 carbon atoms, still more preferably a fatty acid having 12 to 18 carbon atoms
  • Fatty acids more preferably unsaturated fatty acids having 12 to 18 carbon atoms, more preferably oleic acid.
  • the halogen of the halogen-containing substance that is a ligand is not particularly limited, and examples include fluorine, chlorine, bromine, and iodine.
  • the halogen is preferably iodine or bromine, more preferably iodine, from the viewpoints of ease of production, dispersibility, versatility, cost, and excellent performance of quantum dots.
  • halogen-containing substance which is a ligand
  • examples of the halogen-containing substance include iodine, ammonium iodide, and methylammonium iodide. From the point of view, halogen is preferred, and iodine is more preferred.
  • a preferred combination of the perovskite compound and the quantum dots is a combination of compounds containing the same metal element, for example, CH 3 NH 3 , from the viewpoint of uniform dispersibility, durability, and photoelectric conversion efficiency of the quantum dots.
  • the hydrochloride of an organic compound having an amino group and a carboxy group is a salt of an organic compound having an amino group and a carboxy group and hydrogen acid.
  • the organic compound may have two or more amino groups and two or more carboxy groups.
  • the hydrochloride of the organic compound having an amino group and a carboxy group may be used singly or in combination of two or more.
  • the above-mentioned organic compound having an amino group and a carboxyl group and the hydrochloride of the above-mentioned organic compound having an amino group and a carboxyl group may be used in combination. From the viewpoint of the solubility of the organic compound having an amino group and a carboxyl group, it preferably contains a hydrochloride.
  • the organic compound having an amino group and a carboxy group is not particularly limited, and includes, for example, one or more selected from aliphatic amino acids and aromatic amino acids, preferably aliphatic amino acids from the viewpoint of solubility.
  • the aliphatic amino acids and aromatic amino acids are not particularly limited.
  • the aliphatic amino acid may be a linear amino acid or a branched chain amino acid, but from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer, it is preferable. is a straight chain amino acid.
  • the number of carbon atoms in the organic compound having an amino group and a carboxy group is preferably 18 or less, more preferably 10 or less, from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer. More preferably 8 or less, more preferably 2 or more, more preferably 3 or more, still more preferably 4 or more, more preferably 2 or more and 18 or less, more preferably 3 or more and 18 or less, still more preferably 3 10 or less, more preferably 4 or more and 8 or less.
  • the number of carbon atoms is preferably 18 or less from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer. , more preferably 10 or less, more preferably 8 or less, preferably 7 or more, more preferably 8 or more, preferably 7 or more and 18 or less, more preferably 7 or more and 10 or less, still more preferably It is 7 or more and 8 or less.
  • the amino group of the organic compound having an amino group and a carboxy group may be bonded to any carbon in the carbon chain, but the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer From the viewpoint of improvement, it is preferably bonded to a primary carbon.
  • the hydroacid is an oxygen-free acid, for example, hydrohalic acid such as hydrochloric acid, hydrofluoric acid, hydrobromic acid and hydroiodic acid, hydrosulfic acid, hydrocyanic acid, and azide Binary acids such as hydroacid; halogenoacids such as tetrachloroauric ( III) acid ( HAuCl4 ), hexachloroplatinic(IV) acid ( H2PtCl6 ), and tetrafluoroboric acid ( HBF4 ).
  • hydrohalic acid such as hydrochloric acid, hydrofluoric acid, hydrobromic acid and hydroiodic acid, hydrosulfic acid, hydrocyanic acid, and azide Binary acids such as hydroacid
  • halogenoacids such as tetrachloroauric ( III) acid ( HAuCl4 ), hexachloroplatinic(IV) acid ( H2PtCl6 ), and tetrafluoroboric acid (
  • the hydroacid is preferably hydrohalic acid, more preferably hydrobromic acid.
  • Examples of the organic compound having an amino group and a carboxy group include aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminodecanoic acid, aminooctadecanoic acid, aminophenylacetic acid, aminobenzoic acid, and the like. and preferably one or more selected from aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminophenylacetic acid, and aminobenzoic acid.
  • hydrochloride of an organic compound having an amino group and a carboxy group examples include aminobutanoic acid/hydrohalide, aminopentanoic acid/hydrohalide, aminohexanoic acid/hydrohalide, and amino Heptanoic acid/hydrohalide (above, “aliphatic amino acid hydrohalide”), aminophenylacetic acid/hydrohalide, and aminobenzoic acid/hydrohalide (above, “aromatic One or more selected from amino acid hydrohalides”) are preferable, and from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light-absorbing layer, preferably 3-aminopropane acids, 4-aminobutanoic acid hydrobromide, 5-aminopentanoic acid hydrobromide, 6-aminohexanoic acid hydrobromide, and 7-aminoheptanoic acid hydrobromide, and 4-aminophenylacetic acid hydrobromide, such as 4-a
  • aliphatic amino acid hydrochloride or aromatic hydrochloride is preferable, aliphatic amino acid hydrohalide or aromatic amino acid hydrogen halide Acid salts are more preferred, and hydrohalide salts of aliphatic amino acids are even more preferred.
  • the concentration of the perovskite compound and/or its precursor in the dispersion is preferably 0.1 mol/mol/mol from the viewpoint of increasing the content of the perovskite compound in the light absorbing layer and improving the photoelectric conversion efficiency of the solar cell.
  • dm 3 or more more preferably 0.3 mol/dm 3 or more, still more preferably 0.5 mol/dm 3 or more, still more preferably 0.7 mol/dm 3 or more, and the dispersibility of the quantum dots in the dispersion
  • it is preferably 3 mol/dm 3 or less, more preferably 2 mol/dm 3 or less, still more preferably 1.5 mol/dm 3 or less, still more preferably 1 mol/dm 3 or less
  • it is preferably 0.1 mol/dm 3 or more and 3 mol/dm 3 or less, more preferably 0.3 mol/dm 3 or more and 2 mol/dm 3 or less, still more preferably 0.3 mol/dm 3 or more and 1.5 mol.
  • /dm 3 or less more preferably 0.5 mol/dm 3 or more and 1 mol/dm 3 or less, still more preferably 0.7 mol/dm 3 or more and 1 mol/
  • the content and amount of the perovskite compound and/or its precursor in the dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably, from the viewpoint of improving the photoelectric conversion efficiency of the solar cell. is 15% by mass or more, and from the viewpoint of improving dispersion stability, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less, and even more preferably 15% by mass or more and 30% by mass or less.
  • the content and amount of the quantum dots in the dispersion are preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more. From the viewpoint of improving dispersion stability, it is preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less, and from the above viewpoint, preferably 1% by mass or more and 40% by mass. %, more preferably 3% to 30% by mass, and even more preferably 5% to 20% by mass.
  • the content and blending amount of the organic compound having an amino group and a carboxy group and/or a hydrochloride thereof in the dispersion is preferably 0.01% by mass or more, more preferably 0.01% by mass or more, more preferably 0.03% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of reducing manufacturing costs and improving photoelectric conversion efficiency, preferably 20% by mass or less, more preferably 10% by mass or less, and further It is preferably 5% by mass or less, and from the above viewpoint, preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.03% by mass or more and 10% by mass or less, and still more preferably 0.1% by mass. It is more than 5 mass % or less.
  • the organic compound having an amino group and a carboxyl group and/or a hydride thereof means the organic compound having an amino group and a carboxyl group, the hydride of an organic compound having an amino group and a carboxyl group, the amino and a carboxy group-containing organic compound and the hydrochloride salt of the above-mentioned organic compound having an amino group and a carboxy group.
  • the total mass ratio of the organic compound having an amino group and a carboxy group and its hydride (total of the organic compound and its hydride
  • the mass of / the mass of the quantum dot) is preferably 0.001 or more, more preferably 0.003 or more, and still more preferably 0 from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion liquid.
  • the total mass ratio of the organic compound having an amino group and a carboxyl group and its hydride to the quantum dots (including ligands) in the dispersion is also the same as above.
  • quantum dots are calculated including ligands unless otherwise specified.
  • the mass ratio of the quantum dots to the perovskite compound and/or its precursor in the dispersion is the content ratio of the quantum dots in the light absorption layer.
  • the dispersion liquid preferably contains a solvent from the viewpoint of film-forming properties, cost, storage stability, and excellent performance (for example, photoelectric conversion characteristics).
  • solvents include esters (methyl formate, ethyl formate, etc.), ketones ( ⁇ -butyrolactone, N-methyl-2-pyrrolidone, acetone, dimethyl ketone, diisobutyl ketone, etc.), ethers (diethyl ether, methyl-tert-butyl ether, dimethoxymethane, 1,4-dioxane, tetrahydrofuran, etc.), alcohols (methanol, ethanol, 2-propanol, tert-butanol, methoxypropanol, diacetone alcohol, cyclohexanol, 2-fluoroethanol, 2 , 2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, etc.), glycol ethers (cellosolve),
  • the solvent for the dispersion liquid is preferably a polar solvent, more preferably ketones, an amide solvent, and dimethyl sulfoxide, from the viewpoint of film forming properties, cost, storage stability, and excellent performance (e.g., photoelectric conversion characteristics).
  • a method for producing the light absorption layer is not particularly limited, and a preferred example thereof is a so-called wet process method in which the dispersion is applied onto a substrate and dried.
  • a manufacturing method including the following steps 1, 2, and 3 is preferred from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like.
  • Step 1 Step of obtaining a quantum dot solid containing an organic ligand, or ligand exchange of the organic ligand with a halogen-containing substance to obtain a quantum dot solid containing a halogen-containing substance as a ligand Step
  • Step 2 A solution or mixture containing the quantum dot solid obtained in Step 1, one or more substances selected from perovskite compounds and precursors thereof, an organic compound having an amino group and a carboxyl group, and/or a step of obtaining the dispersion by mixing with the hydrochloride (step 3) a step of obtaining a light absorbing layer from the dispersion obtained in step 2;
  • step 1 of obtaining a quantum dot solid containing a halogen-containing substance as a ligand by exchanging the organic ligand of the quantum dot solid containing the organic ligand with a halogen-containing substance (step 1) It is preferable from the viewpoint of improving the dispersibility of the dispersion liquid and from the viewpoint of improving the photoelectric conversion efficiency by improving the carrier moving speed in the light absorbing layer.
  • quantum dots are sometimes synthesized using organic compounds with relatively large molecular sizes and hydrophobicity, such as oleic acid, as ligands. be.
  • quantum dots exhibit excellent dispersibility in non-(low) polar organic solvents such as toluene, but poor dispersibility in polar organic solvents such as N,N-dimethylformamide and methanol. Therefore, when the solvent for dispersing or dissolving the perovskite compound and/or its precursor is a polar organic solvent, it is necessary to disperse the quantum dots in the polar organic solvent. Coordination is preferred.
  • a hydrophobic organic compound having a relatively large molecular size such as oleic acid, has low conductivity and inhibits diffusion of carriers in the light absorption layer. Therefore, from the viewpoint of improving the carrier transfer speed in the light absorption layer and improving the photoelectric conversion efficiency, it is preferable to coordinate the quantum dots with a substance having a relatively small molecular size.
  • the ligand of the quantum dot is preferably one or more halogen-containing substances selected from iodine, ammonium iodide, methylammonium iodide, bromine, ammonium bromide, and methylammonium bromide. and more preferably iodine or bromine, and still more preferably iodine.
  • a method for ligand exchange of the organic ligand of the quantum dot containing the organic ligand to the halogen-containing substance from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc.
  • a method of exchanging ligands in a dispersion is preferred, and a quantum dot dispersion containing an organic ligand and a raw material solution of a halogen-containing substance are mixed at room temperature (25 ° C.) without stirring over a period of time, and then allowed to stand still.
  • a method of exchanging ligands by placing is more preferable.
  • Raw materials for halogen-containing substances used for ligand exchange include methylammonium iodide (methylamine hydroiodide), ammonium iodide, iodine, methylammonium bromide (methylamine hydrobromide), bromine Ammonium chloride, bromine, and the like are preferably mentioned, but from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., methylammonium iodide (methylamine hydroiodide) is preferable.
  • ammonium iodide methylammonium bromide (methylamine hydrobromide), and one or more selected from ammonium bromide, more preferably methylammonium iodide (methylamine hydroiodide), and bromine
  • ammonium iodide methylammonium bromide
  • methylammonium bromide methylammonium bromide
  • bromine One or more selected from methylammonium iodide (methylamine hydroiodide), more preferably methylammonium iodide (methylamine hydroiodide).
  • the mixed amount of the halogen-containing substance raw material used for ligand exchange is determined as the molar ratio of halogen to the organic compound on the surface of the quantum dots. , preferably 0.1 or more, more preferably 1 or more, still more preferably 1.5 or more, preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, still more preferably 3 or less.
  • the solvent used for ligand exchange is preferably a solvent that disperses the quantum dots well and a halogen-containing substance raw material. It is a mixed solvent with a solvent that allows
  • the dispersion solvent for the quantum dots is preferably one or more non-(low) polar organic solvents selected from toluene, hexane, octane, etc., more preferably toluene.
  • the dissolving solvent for the halogen-containing substance raw material is preferably one or more aprotic polar organic solvents selected from N,N-dimethylformamide, dimethylsulfoxide, ⁇ -butyrolactone, etc., more preferably N,N-dimethylformamide. is.
  • the quantum dot solid content concentration in the quantum dot dispersion mixed during ligand exchange is preferably 10 mg / mL or more, from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc. It is preferably 50 mg/mL or more, more preferably 80 mg/mL or more, preferably 1000 mg/mL or less, more preferably 500 mg/mL or less, still more preferably 200 mg/mL or less, still more preferably 120 mg/mL or less.
  • the concentration of the halogen-containing substance raw material in the halogen-containing substance raw material solution mixed during ligand exchange is preferably 0.01 mol/L from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. Above, more preferably 0.1 mol/L or more, still more preferably 0.2 mol/L or more, preferably 1 mol/L or less, more preferably 0.5 mol/L or less, still more preferably 0.3 mol/L or less is.
  • the method of mixing the quantum dot dispersion and the raw material solution of the halogen-containing substance at the time of ligand exchange is not particularly limited as long as it is a method of mixing for a long time under no stirring. From the viewpoints of cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., the continuous method or the dropping method (semi-continuous method) is preferred, and the dropping method is more preferred.
  • a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion or a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion may be used. From the viewpoints of properties, improvement of photoelectric conversion efficiency, etc., a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion is preferable.
  • the mixing speed is preferably 25 ⁇ L/sec or less, more preferably 5 ⁇ L/sec or less, and still more preferably 3 ⁇ L/sec or less from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. , preferably 0.2 ⁇ L/sec or more, more preferably 0.4 ⁇ L/sec or more, and still more preferably 1.5 ⁇ L/sec or more.
  • a method of dropping the halogen-containing substance raw material solution into the quantum dot dispersion or a method of dropping the quantum dot dispersion into the halogen-containing substance raw material solution may be used.
  • the method of dropping the halogen-containing material raw material solution into the quantum dot dispersion is preferable.
  • the dropping rate is preferably 1 drop/second or less, more preferably 1 drop/5 seconds or less, and still more preferably 1 drop, from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. /8 sec or less, preferably 1 drop/100 sec or more, more preferably 1 drop/50 sec or more, and still more preferably 1 drop/15 sec or more.
  • the time for standing still is preferably 0.1 hour or more from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. , more preferably 1 hour or more, still more preferably 10 hours or more, preferably 100 hours or less, more preferably 48 hours or less, still more preferably 24 hours or less.
  • a washing solvent is added to a mixed dispersion of a quantum dot dispersion and a halogen-containing substance raw material solution
  • a preferred method is to obtain a quantum dot solid through a step of filtering to remove the organic compound coordinated to the quantum dot surface, excess halogen-containing raw material, and solvent.
  • the washing solvent is preferably an organic solvent in which the quantum dots before and after ligand exchange are difficult to disperse and in which organic compounds and halogen-containing substances are soluble. From the viewpoint of improving the conversion efficiency, more preferably an alcohol solvent, still more preferably methanol.
  • the amount of the washing solvent is preferably 0.1 or more, more preferably 0.5 or more, and still more preferably 1 as a volume ratio of the washing solvent to the mixed dispersion of the quantum dot dispersion and the halogen-containing material raw material solution. or more, preferably 10 or less, more preferably 5 or less, and still more preferably 2 or less.
  • the filter pore size at the time of filtration is preferably 0.1 ⁇ m or more, more preferably 0.2 ⁇ m or more, and preferably 1 ⁇ m or less. , and more preferably 0.5 ⁇ m or less.
  • the filter material is preferably hydrophobic, more preferably polytetrafluoroethylene (PTFE).
  • a solution or mixture containing the quantum dot solid obtained in step 1, one or more substances selected from perovskite compounds and their precursors, and a hydrochloride of an organic compound having an amino group and a carboxy group are mixed.
  • step (step 2) one or more selected from perovskite compounds and precursors thereof, quantum dots having the ligand, and an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof are prepared. It is preferred to obtain a dispersion comprising
  • the step (step 3) of obtaining a light absorbing layer from the dispersion obtained in step 2 is preferably a wet process such as coating the substrate (functional layer) with the dispersion obtained in step 2.
  • a wet process such as coating the substrate (functional layer) with the dispersion obtained in step 2.
  • gravure coating method, bar coating method, printing method, spray method, spin coating method, dip method, and die coating method, etc. from the viewpoint of ease of production, cost, excellent performance (e.g., photoelectric conversion characteristics) expression , preferably a spin coating method.
  • the maximum rotation speed of the spin coater in the spin coating method is preferably 500 rpm or more, more preferably 1000 rpm or more, still more preferably 2000 rpm or more, and preferably 8000 rpm or less, from the viewpoint of expressing excellent performance (e.g., photoelectric conversion characteristics). , more preferably 7000 rpm or less, still more preferably 6000 rpm or less.
  • a poor solvent for the perovskite compound may be applied or dropped after the dispersion is applied onto the substrate to improve the perovskite compound crystal precipitation rate.
  • the poor solvent is preferably toluene, chlorobenzene, dichloromethane, or a mixed solvent thereof.
  • the drying method in the wet process includes, for example, heat drying, airflow drying, vacuum drying, etc., preferably heat drying, from the viewpoint of ease of production, cost, and expression of excellent performance (e.g., photoelectric conversion characteristics).
  • the temperature for thermal drying is preferably 60° C. or higher, more preferably 80° C. or higher, and still more preferably 90° C. or higher from the viewpoint of expressing excellent performance (e.g., photoelectric conversion characteristics). Therefore, the temperature is preferably 200° C. or lower, more preferably 150° C. or lower, still more preferably 120° C. or lower, and still more preferably 110° C. or lower.
  • the heat drying time is preferably 1 minute or more, more preferably 5 minutes or more, and still more preferably 8 minutes or more from the viewpoint of exhibiting excellent performance (e.g., photoelectric conversion characteristics), from the same viewpoint and cost viewpoint. Therefore, the time is preferably 120 minutes or less, more preferably 60 minutes or less, still more preferably 20 minutes or less, still more preferably 12 minutes or less.
  • the light-absorbing layer of the present invention contains the perovskite compound, the quantum dot having the ligand, and the organic compound having the amino group and the carboxy group and/or the hydride thereof.
  • the light-absorbing layer of the invention may contain light-absorbing agents other than those described above as long as the effects of the invention are not impaired.
  • the light absorption layer of the present invention may have an intermediate band.
  • the intermediate band is an energy level formed by interactions between quantum dots within the bandgap of the perovskite compound, and exists at energy positions near the lower end of the conduction band and/or the upper end of the valence band of the quantum dots.
  • the intermediate band is formed, for example, by regularly arranging quantum dots in a perovskite compound matrix at high density. If an intermediate band exists within the band gap of the perovskite compound, for example, two-step light absorption occurs, in which electrons photoexcited from the valence band of the perovskite compound to the intermediate band are further photoexcited from the intermediate band to the conduction band of the perovskite compound. Therefore, the presence of the intermediate band can be confirmed by measuring the quantum yield of the two-step light absorption, that is, the external quantum yield difference.
  • the crystallite diameter of the perovskite compound in the light absorption layer is preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm or more, and even more preferably 40 nm, from the viewpoint of improving the carrier transfer efficiency and photoelectric conversion efficiency. From the same point of view, the thickness is preferably 1000 nm or less.
  • the perovskite compound of the light-absorbing layer is analyzed, for example, by elemental analysis, infrared (IR) spectrum, Raman spectrum, nuclear magnetic resonance (NMR) spectrum, X-ray diffraction pattern, absorption spectrum, emission spectrum, electron microscope observation, and electron beam diffraction. It can be identified by a conventional method such as.
  • Quantum dots in the light-absorbing layer are, for example, elemental analysis, infrared (IR) spectrum, Raman spectrum, nuclear magnetic resonance (NMR) spectrum, X-ray diffraction pattern, absorption spectrum, emission spectrum, small angle X-ray scattering, electron microscope observation , and electron beam diffraction.
  • the content of quantum dots in the light absorption layer is such that the quantum dots are densely packed to reduce the distance between the quantum dots and interact between the quantum dots to form an intermediate band in the light absorption layer, From the viewpoint of improving the quantum yield of two-stage light absorption, it is preferably 5 vol% or more, more preferably 7.5 vol% or more, still more preferably 10 vol% or more, and still more preferably 12 vol% or more. It is preferably 40 vol% or less, more preferably 30 vol% or less, still more preferably 25 vol% or less from the viewpoint of suppressing carrier transfer from the perovskite compound to the quantum dots and improving the photoelectric conversion efficiency.
  • the content of quantum dots in the light absorption layer means the volume ratio of quantum dots having ligands to the total volume of quantum dots having perovskite compounds and ligands.
  • the thickness of the light absorption layer is not particularly limited, it is preferably 30 nm or more, more preferably 50 nm or more, and still more preferably 80 nm or more from the viewpoint of increasing light absorption and improving photoelectric conversion efficiency. It is preferably 1000 nm or less, more preferably 800 nm or less, still more preferably 600 nm or less, still more preferably 500 nm or less from the viewpoint of improving the photoelectric conversion efficiency by improving the carrier transfer efficiency to the layer or the electron transport agent layer. Note that the thickness of the light absorbing layer can be measured by a measuring method such as electron microscope observation of a film cross section.
  • the photoelectric conversion element of the present invention has the light absorption layer.
  • the configuration of a known photoelectric conversion device can be applied to the configuration other than the light absorption layer.
  • the photoelectric conversion element of the present invention can be manufactured by a known method except for the light absorption layer.
  • FIG. 1 is only an example and is not limited to the embodiment shown in FIG.
  • FIG. 1 is a schematic cross-sectional view showing an example of the structure of the photoelectric conversion element of the present invention.
  • the photoelectric conversion element 1 has a structure in which a transparent substrate 2, a transparent conductive layer 3, a blocking layer 4, a porous layer 5, a light absorption layer 6, and a hole transport layer 7 are sequentially laminated.
  • the transparent electrode substrate on the incident side of the light 10 is composed of a transparent substrate 2 and a transparent conductive layer 3, and the transparent conductive layer 3 is joined to an electrode (negative electrode) 9 serving as a terminal for electrical connection with an external circuit.
  • the hole transport layer 7 is joined to an electrode (positive electrode) 8 that serves as a terminal for electrical connection with an external circuit.
  • the material for the transparent substrate 2 it is sufficient that it has strength, durability, and light transmittance, and synthetic resin, glass, etc. can be used.
  • synthetic resins include thermoplastic resins such as polyethylene naphthalate (PEN) film, polyethylene terephthalate (PET), polyesters, polycarbonates, polyolefins, polyimides, and fluorine resins. From the viewpoint of strength, durability, cost, etc., it is preferable to use a glass substrate.
  • Materials for the transparent conductive layer 3 include, for example, tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide (SnO 2 ), indium zinc oxide (IZO), zinc oxide (ZnO), and high Examples thereof include polymer materials having electrical conductivity. Examples of polymer materials include polyacetylene-based, polypyrrole-based, polythiophene-based, and polyphenylenevinylene-based polymer materials. Also, as the material of the transparent conductive layer 3, a carbon-based thin film having high conductivity can be used. Methods for forming the transparent conductive layer 3 include a sputtering method, a vapor deposition method, and a method of applying a dispersion.
  • Examples of materials for the blocking layer 4 include titanium oxide, aluminum oxide, silicon oxide, niobium oxide, tungsten oxide, tin oxide, and zinc oxide.
  • Methods of forming the blocking layer 4 include a method of directly sputtering the above material onto the transparent conductive layer 3, a spray pyrolysis method, and the like. Further, a method of applying a solution obtained by dissolving the above materials in a solvent or a solution obtained by dissolving a metal hydroxide, which is a precursor of a metal oxide, onto the transparent conductive layer 3, drying and, if necessary, baking. be done.
  • Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
  • the porous layer 5 is a layer having a function of supporting the light absorbing layer 6 on its surface. In order to increase the light absorption efficiency of a solar cell, it is preferable to increase the surface area of the portion that receives light. By providing the porous layer 5, the surface area of the portion that receives light can be increased.
  • Materials for the porous layer 5 include, for example, metal oxides, metal chalcogenides (e.g., sulfides, selenides, etc.), compounds having a perovskite crystal structure (excluding the light absorbers), and silicon oxides. (eg, silicon dioxide and zeolites), and carbon nanotubes (including carbon nanowires and carbon nanorods, etc.).
  • metal oxides e.g., metal oxides, metal chalcogenides (e.g., sulfides, selenides, etc.), compounds having a perovskite crystal structure (excluding the light absorbers), and silicon oxides. (eg, silicon dioxide and zeolites), and carbon nanotubes (including carbon nanowires and carbon nanorods, etc.).
  • metal oxides include oxides of titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, aluminum, and tantalum. , such as zinc sulfide, zinc selenide, cadmium sulfide, and cadmium selenide.
  • Examples of compounds having a perovskite crystal structure include strontium titanate, calcium titanate, barium titanate, lead titanate, barium zirconate, barium stannate, lead zirconate, strontium zirconate, strontium tantalate, and niobate. Potassium, bismuth ferrate, strontium barium titanate, barium lanthanum titanate, calcium titanate, sodium titanate, and bismuth titanate.
  • the material for forming the porous layer 5 is preferably used as fine particles, more preferably as a dispersion containing fine particles.
  • Methods for forming the porous layer 5 include, for example, a wet method, a dry method, and other methods (for example, the method described in Chemical Review, Vol. 110, p. 6595 (published in 2010)). In these methods, it is preferable to apply the dispersion (paste) to the surface of the blocking layer 4 and then bake it. By firing, fine particles can be brought into close contact with each other. Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
  • the light absorption layer 6 is the light absorption layer of the present invention described above.
  • the method for forming the light absorption layer 6 is not particularly limited, and for example, a perovskite compound and/or a precursor thereof, quantum dots having ligands, and a hydrochloride of an organic compound having an amino group and a carboxy group are used.
  • a preferred method is a so-called wet process in which a dispersion is prepared, the prepared dispersion is applied to the surface of the porous layer 5, and dried.
  • the method of forming the light absorbing layer 6 is preferably a manufacturing method including the above-described steps 1, 2 and 3 from the viewpoints of ease of manufacture, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like.
  • Materials for the hole transport layer 7 include, for example, carbazole derivatives, polyarylalkane derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorene derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic derivatives. tertiary amine compounds, styrylamine compounds, aromatic dimethylidine compounds, porphyrin compounds, phthalocyanine compounds, polythiophene derivatives, polypyrrole derivatives, and polyparaphenylenevinylene derivatives.
  • Examples of the method for forming the hole transport layer 7 include a coating method and a vacuum deposition method. Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
  • Materials for the electrode (positive electrode) 8 and the electrode (negative electrode) 9 include, for example, metals such as aluminum, gold, silver, and platinum; tin-added indium oxide (ITO), indium zinc oxide (IZO), and zinc oxide (ZnO). organic conductive materials such as conductive polymers; and carbon-based materials such as nanotubes.
  • Methods for forming the electrode (positive electrode) 8 and the electrode (negative electrode) 9 include, for example, a vacuum vapor deposition method, a sputtering method, and a coating method.
  • the solar cell of the present invention has the photoelectric conversion element.
  • the configuration other than the light absorption layer is not particularly limited, and known solar cell configurations can be applied.
  • the perovskite compound is one or more selected from compounds represented by the following general formula (1) and compounds represented by the following general formula (2).
  • RMX 3 (1) (Wherein, R is a monovalent cation, M is a divalent metal cation, and X is a halogen anion.)
  • the organic compound having an amino group and a carboxy group is at least one selected from aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminophenylacetic acid, and aminobenzoic acid. ] to [8].
  • the hydrochloride of an organic compound having an amino group and a carboxy group is preferably an aliphatic amino acid hydrochloride or an aromatic amino acid hydrochloride, and an aliphatic amino acid hydrohalide or an aromatic amino acid halogenation. Hydrochlorides are more preferred, and aliphatic amino acid hydrohalides are even more preferred. One or more selected from heptanoic acid/hydrohalide, aminophenylacetic acid/hydrohalide, and aminobenzoic acid/hydrohalide are more preferable, any of [1] to [7] The dispersion described in . [11] [ 1] to the dispersion liquid according to any one of [10].
  • the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.001 or more, the dispersion according to any one of [1] to [18].
  • the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.001 or more and 5 or less, the dispersion according to any one of [1] to [19].
  • the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.003 or more and 1.5 or less, the dispersion according to any one of [1] to [20].
  • the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.01 or more and 1.1 or less, the dispersion according to any one of [1] to [21].
  • the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dots) is 0.03 or more and 0.8 or less.
  • the mass ratio of the quantum dots to the perovskite compound and/or its precursor is 0.1 or more [1] to [23] The dispersion according to any one of [23]. [25] [1 ] to [24]. [26] [1 ] to [25].
  • the mass ratio of the quantum dots to the perovskite compound and/or its precursor [the quantum dots/(the perovskite compound and/or its precursor)] is 0.3 or more and 0.7 or less.
  • the dispersion liquid according to any one of [1] to [26].
  • the hydrochloride of the organic compound having an amino group and a carboxyl group and/or its content or amount) is 0.1% by mass or more and 5% by mass or less, [1] to [35] The dispersion according to any one of . [37] The dispersion according to any one of [1] to [36], which is for forming a light absorption layer. [38] A light absorbing layer obtained from the dispersion according to any one of [1] to [37]. [39] A light absorption layer containing a perovskite compound, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof.
  • the light-absorbing layer according to [39], wherein the organic compound having an amino group and a carboxy group is one or more selected from aliphatic amino acids and aromatic amino acids.
  • a photoelectric conversion device comprising the light absorption layer according to any one of [38] to [47].
  • a solar cell comprising the photoelectric conversion element according to [48].
  • the absorption spectrum of the light-absorbing layer was measured using a UV-Vis spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) in a sample before applying the hole transport agent, using a medium scan speed, a sample pitch of 1 nm, and a slit. A range of 300 to 1600 nm was measured under the conditions of a width of 20 and a detector unit integrating sphere. Background measurement was performed using an FTO (fluorine-doped tin oxide) substrate (25 ⁇ 25 ⁇ 1.8 mm, manufactured by Asahi Glass Fabricec Co., Ltd.).
  • FTO fluorine-doped tin oxide
  • the absorption spectrum of the oleic acid-coordinated PbS quantum dot dispersion was similarly measured using a 1 cm square quartz cell in a PbS quantum dot solid dispersion with a concentration of 0.1 mg/mL or more and 1 mg/mL or less.
  • the 300 mL three-necked flask was removed from the mantle and immersed in pre-chilled iron powder for rapid cooling to stop the reaction.
  • the collected reaction liquid was divided into two equal parts, and 40 g of hexane and 200 g of acetone were added to each of the equal parts, followed by vigorous shaking for washing. Thereafter, centrifugation (CR21GIII, R15A rotor, manufactured by Hitachi Koki Co., Ltd., 6000 rpm, 5 minutes) was applied, and after centrifugation, the supernatant was removed and the precipitates were collectively recovered.
  • the collected precipitate was dried under reduced pressure to obtain a PbS quantum dot solid with coordinated oleic acid.
  • the crystallite diameter was 2.7 nm from the X-ray diffraction results, and the absorption edge wavelength was 1070 nm and the absorption peak wavelength was 970 nm from the absorption spectrum (peak absorbance of solid content concentration 1 mg/mL hexane dispersion: 0.501).
  • the methylamine hydroiodide solution was added to the PbS quantum dot dispersion at a drop rate of 1 drop/10 seconds (dropping time: 11 minutes). After dropping, it was allowed to stand still for 18 hours. Further, 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 ⁇ m, material: PTFE), and dried to obtain a PbS quantum dot solid with iodine coordinated.
  • the above amino acid salt solution was added dropwise to the PbS quantum dot dispersion at a dropping rate of 1 drop/10 seconds, and then allowed to stand for 18 hours. Further, 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 ⁇ m, material: PTFE), and dried to obtain a PbS quantum dot solid with 4-aminobutanoic acid coordinated.
  • the above amino acid salt solution was added dropwise to the PbS quantum dot dispersion at a dropping rate of 1 drop/10 seconds, and then allowed to stand for 18 hours.
  • 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 ⁇ m, material: PTFE), and dried to obtain a PbS quantum dot solid with 7-aminoheptanoic acid coordinated.
  • Example 1 A cell was fabricated by performing the following steps (1) to (7) in order.
  • FTO substrate fluorine-doped tin oxide
  • mesoporous TiO 2 layer 0.4 g of anatase-type TiO 2 paste (PST-18NR, manufactured by Nikki Shokubai Kasei Co., Ltd.) was added with ethanol (dehydrated, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)3. 2 g was added and ultrasonically dispersed for 1 hour to prepare a TiO 2 coating liquid. In a dry room, a TiO 2 coating solution was spin-coated on the cTiO 2 layer using a spin coater (manufactured by Mikasa Corporation, MS-100) (slope 3 sec, 4000 rpm ⁇ 30 sec). A mesoporous TiO 2 (mTiO 2 ) layer was formed by drying on a hot plate at 110° C. for 30 minutes and baking at 500° C. for 30 minutes (heating time: 60 minutes).
  • PST-18NR manufactured by Nikki Shokubai Kasei Co., Ltd.
  • the light-absorbing layer contains the perovskite compound CH 3 NH 3 PbBr 3 , PbS quantum dots, ligands, and 4-aminobutanoic acid hydrobromide. It was confirmed from the X-ray diffraction pattern and absorption spectrum that a perovskite compound was produced, and the presence of quantum dots was confirmed from the absorption spectrum.
  • the HTM solution was filtered through a 0.45 ⁇ m pore size PTFE filter.
  • the HTM solution was spin-coated on the light absorption layer using a spin coater (manufactured by Mikasa Corporation, MS-100) (slope 3 sec, 4000 rpm ⁇ 30 sec). Immediately after spin coating, it was dried on a 70° C. hot plate for 10 minutes. After drying, a cotton swab impregnated with ⁇ -butyrolactone (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used to wipe off the contact portion with FTO and the entire back surface of the substrate to form a hole transport layer.
  • Example 2 A dispersion for forming a light absorption layer was prepared in the same manner as in Example 1, except that the amount of 4-aminobutanoic acid hydrobromide was changed to 0.0542 g, and a light absorption layer was formed. , a cell was fabricated. Regarding the power generation performance of the produced solar cell, the conversion efficiency obtained from the IV curve was 0.08 (%), the short-circuit current density was 0.19 (mA/cm 2 ), the open-circuit voltage was 0.85 (V), and fill factor (FF) was 0.48.
  • Example 3 In Example 1, the amount of lead bromide was 0.183 g, the amount of methylamine hydrobromide was 0.056 g, the amount of 4-aminobutanoic acid hydrobromide was 0.00021 g, and iodine was coordinated.
  • a dispersion liquid for forming a light absorption layer was prepared in the same manner as in Example 1, except that the amount of the PbS quantum dot solid was changed to 0.081 g, a light absorption layer was formed, and a cell was produced.
  • Example 4 In Example 3, a light absorption layer forming dispersion was prepared in the same manner as in Example 3, except that the amount of 4-aminobutanoic acid hydrobromide was changed to 0.0021 g, and a light absorption layer was formed. , a cell was fabricated.
  • Example 5 A light absorbing layer was formed in the same manner as in Example 1, except that 7-aminoheptanoic acid hydrobromide (0.0067 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared, a light absorption layer was formed, and a cell was produced. Regarding the power generation performance of the produced solar cell, the conversion efficiency obtained from the IV curve was 0.06 (%), the short-circuit current density was 0.22 (mA/cm 2 ), the open-circuit voltage was 0.49 (V), and fill factor (FF) was 0.57.
  • Example 6 In Example 1, oleic acid-coordinated PbS quantum dot solids were used instead of iodine-coordinated PbS quantum dot solids, and the charged amount was 0.081 g of oleic acid-coordinated PbS quantum dot solids. - 0.0542 g of aminobutanoic acid hydrobromide, shake the test tube by hand for 5 minutes, then ultrasonically disperse for 25 minutes, the solid content of the PbS quantum dots coordinated with oleic acid disappears, A dispersion liquid for forming a light absorption layer was prepared in the same manner as in Example 1 except that the dispersion was visually confirmed, a light absorption layer was formed, and a cell was produced.
  • the conversion efficiency obtained from the IV curve was 0.215 (%)
  • the short-circuit current density was 0.62 (mA/cm 2 )
  • the open-circuit voltage was 0.59 (V)
  • fill factor (FF) was 0.58.
  • Example 7 A dispersion for forming a light absorbing layer was prepared in the same manner as in Example 1, except that 4-aminophenylacetic acid (0.0017 g) was used instead of 4-aminobutanoic acid hydrobromide. bottom.
  • Example 8 A light absorption layer was formed in the same manner as in Example 1, except that 4-aminophenylacetic acid hydrobromide (0.0026 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared for
  • Example 9 A dispersion for forming a light absorbing layer was prepared in the same manner as in Example 1, except that 4-aminobenzoic acid (0.0016 g) was used instead of 4-aminobutanoic acid hydrobromide. bottom.
  • Example 10 A light absorbing layer was formed in the same manner as in Example 1, except that 4-aminobenzoic acid hydrobromide (0.0025 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared for
  • 0.014 g of the above iodine-coordinated PbS quantum dot solid is added to this DMF/DMSO solution, and the test tube is shaken by hand for 5 minutes to eliminate the solid content of the iodine-coordinated PbS quantum dots. This was visually confirmed, and a dispersion liquid for forming a light absorbing layer was obtained.
  • a light absorbing layer was formed in the same manner as in Example 1 except that the dispersion for forming a light absorbing layer was used, and a cell was produced.
  • Comparative example 2 Light absorption was performed in the same manner as in Comparative Example 1, except that in Comparative Example 1, a 4-aminobutanoic acid-coordinated PbS quantum dot solid (0.044 g) was used instead of the iodine-coordinated PbS quantum dot solid. A layer forming dispersion was prepared, a light absorption layer was formed, and a cell was produced.
  • Comparative example 3 In Comparative Example 1, light was emitted in the same manner as in Comparative Example 1, except that 7-aminoheptanoic acid-coordinated PbS quantum dot solid (0.0044 g) was used instead of the iodine-coordinated PbS quantum dot solid. A dispersion liquid for forming an absorption layer was prepared, a light absorption layer was formed, and a cell was produced.
  • the dispersion is preferably stable for 5 days or more, more preferably 10 days or more.
  • Example 6 no sedimentation occurred for 10 days, and when the long-term dispersion stability of the dispersion was evaluated, it was confirmed to be stable without sedimentation for 90 days.
  • Example 7 was stable up to 13 days, while Example 8 was stable for 15 days or more.
  • the dispersion of the present invention can be suitably used as a dispersion for forming a light absorption layer.
  • the light absorbing layer and photoelectric conversion element of the present invention can be suitably used as constituent members of next-generation solar cells.
  • photoelectric conversion element 2 transparent substrate 3: transparent conductive layer 4: blocking layer 5: porous layer 6: light absorption layer 7: hole transport layer 8: electrode (positive electrode) 9: Electrode (negative electrode) 10: light

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Abstract

The present invention pertains to: a liquid dispersion which has excellent stability and in which aggregates and precipitates are less likely to occur even when containing quantum dots and a perovskite compound and/or a precursor thereof at a high concentration; a light absorption layer obtained from the liquid dispersion; a photoelectric conversion element having the light absorption layer; and a solar cell having the photoelectric conversion element. The liquid dispersion according to the present invention contains: a perovskite compound and/or a precursor thereof; quantum dots having a ligand; and a hydroacid salt of an organic compound having an amino group and a carboxy group.

Description

分散液、光吸収層、光電変換素子、及び太陽電池Dispersion liquid, light absorption layer, photoelectric conversion element, and solar cell
　本発明は、光吸収層を形成するための分散液、前記分散液から得られる光吸収層、前記光吸収層を有する光電変換素子、及び前記光電変換素子を有する太陽電池に関する。 The present invention relates to a dispersion for forming a light absorption layer, a light absorption layer obtained from the dispersion, a photoelectric conversion element having the light absorption layer, and a solar cell having the photoelectric conversion element.
　光エネルギーを電気エネルギーに変える光電変換素子は、太陽電池、光センサー、複写機などに利用されている。特に、環境・エネルギー問題の観点から、無尽蔵のクリーンエネルギーである太陽光を利用する光電変換素子（太陽電池）が注目されている。 Photoelectric conversion elements that convert light energy into electrical energy are used in solar cells, light sensors, copiers, etc. In particular, from the viewpoint of environmental and energy problems, photoelectric conversion elements (solar cells) that utilize sunlight, which is inexhaustible clean energy, have attracted attention.
　一般的なシリコン太陽電池は、超高純度のシリコンを利用すること、高真空下でのエピタキシャル結晶成長などの「ドライプロセス」により製造していること、などから、大きなコストダウンが期待できない。そこで、塗布プロセスなどの「ウエットプロセス」により製造される太陽電池が、低コストな次世代太陽電池として期待されている。 　Common silicon solar cells cannot be expected to significantly reduce costs because they use ultra-pure silicon and are manufactured by "dry processes" such as epitaxial crystal growth under high vacuum. Therefore, a solar cell manufactured by a "wet process" such as a coating process is expected as a low-cost next-generation solar cell.
　例えば、次世代太陽電池の最有力候補として、ペロブスカイト化合物（ＣＨ３ＮＨ３ＰｂＩ３）で表面処理したＰｂＳ量子ドットを光吸収層に用いた量子ドット太陽電池が報告されている（非特許文献１）。しかしながら、ペロブスカイト化合物量が少なく、ペロブスカイト化合物の発電の寄与がほとんど無く、変換効率が不十分である。 For example, as the most promising candidate for next-generation solar cells, a quantum dot solar cell using PbS quantum dots surface-treated with a perovskite compound (CH 3 NH 3 PbI 3 ) as a light absorption layer has been reported (Non-Patent Document 1). ). However, the amount of perovskite compound is small, and the perovskite compound hardly contributes to power generation, resulting in insufficient conversion efficiency.
　さらに、可視光領域と近赤外光領域の両領域において光電変換可能な、高変換効率の光電変換素子及び太陽電池を形成するための光吸収層であって、ペロブスカイト化合物と、ハロゲン元素及び有機配位子を含む量子ドットと、を含有し、前記量子ドットを構成する金属元素に対する前記有機配位子のモル比が０．０１以上０．４以下である光吸収層が提案されている（特許文献１）。 Furthermore, a light absorption layer for forming a photoelectric conversion element and a solar cell with high conversion efficiency capable of photoelectric conversion in both the visible light region and the near-infrared light region, comprising a perovskite compound, a halogen element and an organic and a quantum dot containing a ligand, and a light absorption layer in which the molar ratio of the organic ligand to the metal element constituting the quantum dot is 0.01 or more and 0.4 or less ( Patent document 1).
国際公開第２０１８／１６３３２７号WO2018/163327
　ペロブスカイト化合物と量子ドットを含有する光吸収層を用いた太陽電池の光電変換効率を向上させるためには、光吸収層中のペロブスカイト化合物と量子ドットの含有量を増やす必要がある。塗布工程を有するウエットプロセスにおいて、光吸収層中のペロブスカイト化合物と量子ドットの含有量を増やすためには、ペロブスカイト化合物と量子ドットを高濃度で含有する分散液が必要である。しかし、ペロブスカイト化合物と量子ドットを高濃度で含有する分散液は、凝集や沈殿が生じ易く、経時安定性に劣るという問題があった。そのため、ペロブスカイト化合物と量子ドットを高濃度で含有し、かつ凝集や沈殿が生じ難い安定性に優れる分散液が求められる。 In order to improve the photoelectric conversion efficiency of a solar cell using a light absorption layer containing perovskite compounds and quantum dots, it is necessary to increase the content of perovskite compounds and quantum dots in the light absorption layer. In a wet process having a coating step, a dispersion containing a high concentration of a perovskite compound and quantum dots is required in order to increase the contents of the perovskite compound and quantum dots in the light absorbing layer. However, dispersions containing perovskite compounds and quantum dots at high concentrations tend to aggregate or precipitate, and have a problem of poor stability over time. Therefore, there is a demand for a highly stable dispersion that contains perovskite compounds and quantum dots at high concentrations and is less likely to aggregate or precipitate.
　本発明は、ペロブスカイト化合物及び／又はその前駆体と量子ドットを高濃度で含有する場合でも凝集や沈殿が生じ難い安定性に優れる分散液、前記分散液から得られる光吸収層、前記光吸収層を有する光電変換素子、及び前記光電変換素子を有する太陽電池に関する。 The present invention provides a highly stable dispersion that is resistant to aggregation and precipitation even when a perovskite compound and/or its precursor and quantum dots are contained at a high concentration, a light-absorbing layer obtained from the dispersion, and the light-absorbing layer. and a solar cell having the photoelectric conversion element.
　本発明者は、ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットとを含有する分散液に、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩を添加することにより、ペロブスカイト化合物及び／又はその前駆体と量子ドットを高濃度で含有する場合でも凝集や沈殿が生じ難い安定性に優れる分散液が得られることを見出した。 The present inventor adds an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof to a dispersion liquid containing a perovskite compound and/or its precursor and quantum dots having a ligand. Thus, it was found that even when the perovskite compound and/or its precursor and quantum dots are contained at a high concentration, a highly stable dispersion that hardly causes aggregation or sedimentation can be obtained.
　すなわち、本発明は、ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する分散液及び配合してなる分散液に関する。 That is, the present invention provides a dispersion and formulation containing a perovskite compound and/or its precursor, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof. It relates to a dispersion liquid formed by
　また、本発明は、ペロブスカイト化合物と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物の水素酸塩と、を含有する光吸収層に関する。 The present invention also relates to a light absorbing layer containing a perovskite compound, a quantum dot having a ligand, and a hydrochloride of an organic compound having an amino group and a carboxy group.
　本発明の分散液は、アミノ基及びカルボキシ基を有する有機化合物及び／その水素酸塩を含有又は配合しているため、分散液中の量子ドットの分散性及び分散安定性に優れており、ペロブスカイト化合物及び／又はその前駆体と量子ドットを高濃度で含有する場合でも凝集や沈殿が生じ難く、経時安定性に優れている。そのため、本発明の分散液を用いれば、光吸収層中のペロブスカイト化合物と量子ドットの含有量を増やすことが可能であり、太陽電池の光電変換効率を向上させることができる。 Since the dispersion of the present invention contains or contains an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof, it is excellent in dispersibility and dispersion stability of quantum dots in the dispersion, and perovskite Even when the compound and/or its precursor and quantum dots are contained at a high concentration, aggregation and precipitation are unlikely to occur, and the stability over time is excellent. Therefore, by using the dispersion of the present invention, it is possible to increase the contents of the perovskite compound and the quantum dots in the light absorption layer, thereby improving the photoelectric conversion efficiency of the solar cell.
本発明の光電変換素子の構造の一例を示す概略断面図である。It is a schematic sectional drawing which shows an example of the structure of the photoelectric conversion element of this invention.
＜分散液＞
　本発明の分散液は、ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する又は配合してなる。本発明の分散液の量子ドットの分散性及び分散安定性に優れているのは、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩同士が、分子間のアミノ基とカルボキシ基との相互作用により、緩く結合し、紐状になって、量子ドットの周りに、存在し、量子ドットの分散安定性を高めているためと推定される。 <Dispersion>
The dispersion of the present invention contains or blends a perovskite compound and/or precursor thereof, quantum dots having ligands, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof. It becomes The excellent dispersibility and dispersion stability of the quantum dots of the dispersion of the present invention is that the organic compound having an amino group and a carboxy group and / or a hydrochloride thereof is an intermolecular amino group and a carboxy group. It is presumed that due to the interaction of , they are loosely bound, form a string, and exist around the quantum dots, increasing the dispersion stability of the quantum dots.
　前記ペロブスカイト化合物は特に制限されないが、光電変換効率を向上させる観点から、好ましくは下記一般式（１）で表される化合物及び下記一般式（２）で表される化合物から選ばれる１種以上であり、より好ましくは下記一般式（１）で表される化合物である。 The perovskite compound is not particularly limited, but from the viewpoint of improving the photoelectric conversion efficiency, it is preferably one or more selected from compounds represented by the following general formula (1) and compounds represented by the following general formula (2). and more preferably a compound represented by the following general formula (1).
　ＲＭＸ３　　　　（１）
（式中、Ｒは１価のカチオンであり、Ｍは２価の金属カチオンであり、Ｘはハロゲンアニオンである。） RMX 3 (1)
(Wherein, R is a monovalent cation, M is a divalent metal cation, and X is a halogen anion.)
　Ｒ１Ｒ２Ｒ３ ｎ－１ＭｎＸ３ｎ＋１　　　　（２）
（式中、Ｒ１、Ｒ２、及びＲ３はそれぞれ独立に１価のカチオンであり、Ｍは２価の金属カチオンであり、Ｘはハロゲンアニオンであり、ｎは１以上１０以下の整数である。） R 1 R 2 R 3 n−1 M n X 3n+1 (2)
(Wherein, R 1 , R 2 , and R 3 are each independently a monovalent cation, M is a divalent metal cation, X is a halogen anion, and n is an integer of 1 or more and 10 or less. be.)
　前記Ｒは１価のカチオンであり、例えば、周期表第一族元素のカチオン、及び有機カチオンが挙げられ、光電変換効率を向上させる観点から、好ましくは有機カチオンである。周期表第一族元素のカチオンとしては、例えば、Ｌｉ＋、Ｎａ＋、Ｋ＋、及びＣｓ＋が挙げられる。有機カチオンとしては、例えば、置換基を有していてもよいアンモニウムイオン、及び置換基を有していてもよいホスホニウムイオンが挙げられる。置換基を有していてもよいアンモニウムイオンとしては、例えば、アルキルアンモニウムイオン、ホルムアミジニウムイオン及びアリールアンモニウムイオンが挙げられ、耐久性と光電変換効率を向上させる観点から、好ましくはアルキルアンモニウムイオン及びホルムアミジニウムイオンから選ばれる１種以上であり、より好ましくはモノアルキルアンモニウムイオン及びホルムアミジニウムイオンから選ばれる１種以上であり、更に好ましくはメチルアンモニウムイオン、エチルアンモニウムイオン、ブチルアンモニウムイオン及びホルムアミジニウムイオンから選ばれる１種以上であり、更に好ましくはメチルアンモニウムイオンである。 The R is a monovalent cation, for example, a cation of a Group 1 element of the periodic table and an organic cation, preferably an organic cation from the viewpoint of improving the photoelectric conversion efficiency. Examples of cations of Group 1 elements of the periodic table include Li + , Na + , K + , and Cs + . Examples of organic cations include an ammonium ion which may have a substituent and a phosphonium ion which may have a substituent. Examples of the ammonium ions which may have a substituent include alkylammonium ions, formamidinium ions and arylammonium ions, and from the viewpoint of improving durability and photoelectric conversion efficiency, alkylammonium ions and One or more selected from formamidinium ions, more preferably one or more selected from monoalkylammonium ions and formamidinium ions, still more preferably methylammonium ions, ethylammonium ions, butylammonium ions and form It is one or more selected from amidinium ions, more preferably methylammonium ions.
　前記Ｒ１、Ｒ２、及びＲ３はそれぞれ独立に１価のカチオンであり、Ｒ１、Ｒ２、及びＲ３のいずれかまたは全てが同一でも良い。例えば、周期表第一族元素のカチオン、及び有機カチオンが挙げられる。周期表第一族元素のカチオンとしては、例えば、Ｌｉ＋、Ｎａ＋、Ｋ＋、及びＣｓ＋が挙げられる。有機カチオンとしては、例えば、置換基を有していてもよいアンモニウムイオン、及び置換基を有していてもよいホスホニウムイオンが挙げられる。置換基を有していてもよいアンモニウムイオンとしては、例えば、アルキルアンモニウムイオン、ホルムアミジニウムイオン及びアリールアンモニウムイオンが挙げられ、耐久性と光電変換効率を向上させる観点から、好ましくはアルキルアンモニウムイオン及びホルムアミジニウムイオンから選ばれる１種以上であり、より好ましくはモノアルキルアンモニウムイオンであり、更に好ましくはメチルアンモニウムイオン、エチルアンモニウムイオン、ブチルアンモニウムイオン、ヘキシルアンモニウムイオン、オクチルアンモニウムイオン、デシルアンモニウムイオン、ドデシルアンモニウムイオン、テトラデシルアンモニウムイオン、ヘキサデシルアンモニウムイオン、及びオクタデシルアンモニウムイオンから選ばれる１種以上である。 Each of R 1 , R 2 and R 3 is independently a monovalent cation, and any or all of R 1 , R 2 and R 3 may be the same. Examples include cations of Group 1 elements of the periodic table and organic cations. Examples of cations of Group 1 elements of the periodic table include Li + , Na + , K + , and Cs + . Examples of organic cations include an ammonium ion which may have a substituent and a phosphonium ion which may have a substituent. Examples of the ammonium ions which may have a substituent include alkylammonium ions, formamidinium ions and arylammonium ions, and from the viewpoint of improving durability and photoelectric conversion efficiency, alkylammonium ions and one or more selected from formamidinium ions, more preferably monoalkylammonium ions, still more preferably methylammonium ions, ethylammonium ions, butylammonium ions, hexylammonium ions, octylammonium ions, decylammonium ions, It is one or more selected from dodecylammonium ions, tetradecylammonium ions, hexadecylammonium ions, and octadecylammonium ions.
　前記ｎは１以上１０以下の整数であり、耐久性と光電変換効率を向上させる観点から、好ましくは１以上４以下である。 The n is an integer of 1 or more and 10 or less, and preferably 1 or more and 4 or less from the viewpoint of improving durability and photoelectric conversion efficiency.
　前記Ｍは２価の金属カチオンであり、例えば、Ｐｂ２＋、Ｓｎ２＋、Ｈｇ２＋、Ｃｄ２＋、Ｚｎ２＋、Ｍｎ２＋、Ｃｕ２＋、Ｎｉ２＋、Ｆｅ２＋、Ｃｏ２＋、Ｐｄ２＋、Ｇｅ２＋、Ｙ２＋、及びＥｕ２＋などが挙げられる。前記Ｍは、耐久性（耐湿性）及び光電変換効率に優れる観点から、好ましくはＰｂ２＋、Ｓｎ２＋、又はＧｅ２＋であり、より好ましくはＰｂ２＋、又はＳｎ２＋であり、更に好ましくはＰｂ２＋である。 M is a divalent metal cation such as Pb 2+ , Sn 2+ , Hg 2+ , Cd 2+ , Zn 2+ , Mn 2+ , Cu 2+ , Ni 2+ , Fe 2+ , Co 2+ , Pd 2+ , Ge 2+ , Y 2+ and Eu 2+ and the like. From the viewpoint of excellent durability (humidity resistance) and photoelectric conversion efficiency, M is preferably Pb 2+ , Sn 2+ or Ge 2+ , more preferably Pb 2+ or Sn 2+ , still more preferably Pb 2+ . is.
　前記Ｘはハロゲンアニオンであり、例えば、フッ素アニオン、塩素アニオン、臭素アニオン、及びヨウ素アニオンが挙げられる。前記Ｘは、目的とするバンドギャップエネルギーを有するペロブスカイト化合物を得るために、好ましくはフッ素アニオン、塩素アニオン、又は臭素アニオンであり、より好ましくは塩素アニオン、又は臭素アニオンであり、更に好ましくは臭素アニオンである。 The above X is a halogen anion, such as a fluorine anion, a chlorine anion, a bromine anion, and an iodine anion. X is preferably a fluorine anion, a chloride anion, or a bromine anion, more preferably a chloride anion, or a bromine anion, still more preferably a bromine anion, in order to obtain a perovskite compound having a desired bandgap energy. is.
　前記ペロブスカイト化合物は、光電変換効率を向上させる観点から、好ましくは１．５ｅＶ以上４．０ｅＶ以下のバンドギャップエネルギーを有するものである。前記ペロブスカイト化合物は、１種単独でもよく、バンドギャップエネルギーが異なる２種以上であってもよい。 From the viewpoint of improving the photoelectric conversion efficiency, the perovskite compound preferably has a bandgap energy of 1.5 eV or more and 4.0 eV or less. The perovskite compound may be of one type alone, or two or more types having different bandgap energies.
　前記ペロブスカイト化合物のバンドギャップエネルギーは、光電変換効率（電圧）を向上させる観点から、好ましくは１．７ｅＶ以上、より好ましくは２．０ｅＶ以上、更に好ましくは２．１ｅＶ以上、更に好ましくは２．２ｅＶ以上であり、光電変換効率（電流）を向上させる観点から、好ましくは３．６ｅＶ以下、より好ましくは３．０ｅＶ以下、更に好ましくは２．４ｅＶ以下である。なお、前記ペロブスカイト化合物及び前記量子ドットのバンドギャップエネルギーは、後述する実施例に記載の方法で、２５℃で測定した吸収スペクトルから求めることができる。吸収スペクトルから求めたバンドギャップエネルギーに対応する波長を吸収端波長という。 The bandgap energy of the perovskite compound is preferably 1.7 eV or more, more preferably 2.0 eV or more, still more preferably 2.1 eV or more, still more preferably 2.2 eV, from the viewpoint of improving the photoelectric conversion efficiency (voltage). From the viewpoint of improving the photoelectric conversion efficiency (current), it is preferably 3.6 eV or less, more preferably 3.0 eV or less, and even more preferably 2.4 eV or less. The bandgap energies of the perovskite compound and the quantum dots can be obtained from absorption spectra measured at 25° C. by the method described in Examples below. The wavelength corresponding to the bandgap energy determined from the absorption spectrum is called the absorption edge wavelength.
　１．５ｅＶ以上４．０ｅＶ以下のバンドギャップエネルギーを有する上記一般式（１）で表される化合物としては、例えば、ＣＨ３ＮＨ３ＰｂＣｌ３、ＣＨ３ＮＨ３ＰｂＢｒ３、ＣＨ３ＮＨ３ＰｂＩ３、ＣＨ３ＮＨ３ＰｂＢｒＩ２、ＣＨ３ＮＨ３ＰｂＢｒ２Ｉ、ＣＨ３ＮＨ３ＳｎＣｌ３、ＣＨ３ＮＨ３ＳｎＢｒ３、ＣＨ３ＮＨ３ＳｎＩ３、ＣＨ（＝ＮＨ）ＮＨ３ＰｂＣｌ３、及びＣＨ（＝ＮＨ）ＮＨ３ＰｂＢｒ３などが挙げられる。これらのうち、耐久性と光電変換効率を向上させる観点から、好ましくはＣＨ３ＮＨ３ＰｂＢｒ３、ＣＨ（＝ＮＨ）ＮＨ３ＰｂＢｒ３であり、より好ましくはＣＨ３ＮＨ３ＰｂＢｒ３である。 Examples of the compound represented by the general formula (1) having a bandgap energy of 1.5 eV or more and 4.0 eV or less include CH 3 NH 3 PbCl 3 , CH 3 NH 3 PbBr 3 , CH 3 NH 3 PbI 3 , CH3NH3PbBrI2 , CH3NH3PbBr2I , CH3NH3SnCl3 , CH3NH3SnBr3 , CH3NH3SnI3 , CH ( = NH ) NH3PbCl3 , and CH ( ═NH)NH 3 PbBr 3 and the like. Of these, CH 3 NH 3 PbBr 3 and CH(=NH)NH 3 PbBr 3 are preferred, and CH 3 NH 3 PbBr 3 is more preferred, from the viewpoint of improving durability and photoelectric conversion efficiency.
　１．５ｅＶ以上４．０ｅＶ以下のバンドギャップエネルギーを有する上記一般式（２）で表される化合物としては、例えば、（Ｃ４Ｈ９ＮＨ３）２ＰｂＩ４、（Ｃ６Ｈ１３ＮＨ３）２ＰｂＩ４、（Ｃ８Ｈ１７ＮＨ３）２ＰｂＩ４、（Ｃ１０Ｈ２１ＮＨ３）２ＰｂＩ４、（Ｃ１２Ｈ２５ＮＨ３）２ＰｂＩ４、（Ｃ４Ｈ９ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｉ７、（Ｃ６Ｈ１３ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｉ７、（Ｃ８Ｈ１７ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｉ７、（Ｃ１０Ｈ２１ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｉ７、（Ｃ１２Ｈ２５ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｉ７、（Ｃ４Ｈ９ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｉ１０、（Ｃ６Ｈ１３ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｉ１０、（Ｃ８Ｈ１７ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｉ１０、（Ｃ１０Ｈ２１ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｉ１０、（Ｃ１２Ｈ２５ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｉ１０、（Ｃ４Ｈ９ＮＨ３）２ＰｂＢｒ４、（Ｃ６Ｈ１３ＮＨ３）２ＰｂＢｒ４、（Ｃ８Ｈ１７ＮＨ３）２ＰｂＢｒ４、（Ｃ１０Ｈ２１ＮＨ３）２ＰｂＢｒ４、（Ｃ４Ｈ９ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｂｒ７、（Ｃ６Ｈ１３ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｂｒ７、（Ｃ８Ｈ１７ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｂｒ７、（Ｃ１０Ｈ２１ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｂｒ７、（Ｃ１２Ｈ２５ＮＨ３）２（ＣＨ３ＮＨ３）Ｐｂ２Ｂｒ７、（Ｃ４Ｈ９ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｂｒ１０、（Ｃ６Ｈ１３ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｂｒ１０、（Ｃ８Ｈ１７ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｂｒ１０、（Ｃ１０Ｈ２１ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｂｒ１０、（Ｃ１２Ｈ２５ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｂｒ１０、（Ｃ４Ｈ９ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｃｌ１０、（Ｃ６Ｈ１３ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｃｌ１０、（Ｃ８Ｈ１７ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｃｌ１０、（Ｃ１０Ｈ２１ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｃｌ１０、及び（Ｃ１２Ｈ２５ＮＨ３）２（ＣＨ３ＮＨ３）２Ｐｂ３Ｃｌ１０などが挙げられる。 Examples of compounds represented by the general formula (2) having a band gap energy of 1.5 eV or more and 4.0 eV or less include (C 4 H 9 NH 3 ) 2 PbI 4 and (C 6 H 13 NH 3 ). 2PbI4 , ( C8H17NH3 ) 2PbI4 , ( C10H21NH3 ) 2PbI4 , ( C12H25NH3 ) 2PbI4 , ( C4H9NH3 ) 2 ( CH3NH3 ) Pb2I7 , ( C6H13NH3 ) 2 ( CH3NH3 ) Pb2I7 , ( C8H17NH3 ) 2 ( CH3NH3 ) Pb2I7 , ( C10H21NH3 ) 2 ( CH3NH3 ) Pb2I7 , ( C12H25NH3 ) 2 ( CH3NH3 ) Pb2I7 , ( C4H9NH3 ) 2 ( CH3NH3 ) 2Pb3I10 , ( C6H13NH3 ) 2 ( CH3NH3 ) 2Pb3I10 , ( C8H17NH3 ) 2 ( CH3NH3 ) 2Pb3 _ I10 , ( C10H21NH3 ) 2 ( CH3NH3 ) 2Pb3I10 , ( C12H25NH3 ) 2 ( CH3NH3 ) 2Pb3I10 , ( C4H9 NH3 ) 2PbBr4 , ( C6H13NH3 ) 2PbBr4 , ( C8H17NH3 ) 2PbBr4 , ( C10H21NH3 ) 2PbBr4 , ( C4H9NH3 ) 2 ( CH3NH3 ) Pb2Br7 , ( C6H13NH3 ) 2 ( CH3NH3 ) Pb2Br7 , ( C8H17NH3 ) 2 ( CH3NH3 ) Pb2 Br7 , ( C10H21NH3 ) 2 ( CH3NH3 ) Pb2Br7 , ( C12H25NH3 ) 2 ( CH3NH3 ) Pb2Br7 , ( C4H9NH3 ) 2 ( CH3NH3 ) 2Pb3Br10 , ( C6H13NH3 ) 2 ( CH3NH3 ) 2Pb3Br10 , ( C8H17NH3 ) 2 ( CH3NH3 ) 2Pb3Br10 , ( C10H21NH3 ) 2 ( CH3NH3 ) 2Pb3Br10 , ( C12H25NH3 ) 2 ( CH3NH3 ) 2Pb3Br10 , ( C 4H9NH3 ) 2 ( CH3NH3 ) 2Pb3Cl10 , ( C6H13NH3 ) 2 ( CH3NH3 ) 2Pb3Cl10 , ( C8H17NH3 ) 2 ( CH3NH3 ) 2Pb3Cl10 , ( C10H21NH3 ) 2 ( CH3NH3 ) 2Pb3Cl10 , and ( C12H25NH3 ) 2 ( CH3NH3 ) 2Pb 3 Cl 10 and the like.
　前記ペロブスカイト化合物は、例えば、ペロブスカイト化合物の前駆体から製造することができる。ペロブスカイト化合物の前駆体としては、例えば、ペロブスカイト化合物が前記一般式（１）で表される化合物の場合、ＭＸ２で表される化合物と、ＲＸで表される化合物との組合せが挙げられる。また、ペロブスカイト化合物が前記一般式（２）で表される化合物の場合、ＭＸ２で表される化合物と、Ｒ１Ｘで表される化合物、Ｒ２Ｘで表される化合物、及び任意のＲ３Ｘで表される化合物から選ばれる１種以上との組合せが挙げられる。 The perovskite compound can be produced, for example, from a perovskite compound precursor. Examples of perovskite compound precursors include, when the perovskite compound is the compound represented by the general formula (1), a combination of a compound represented by MX2 and a compound represented by RX. Further, when the perovskite compound is a compound represented by the general formula (2), the compound represented by MX 2 , the compound represented by R 1 X, the compound represented by R 2 X, and any R A combination with one or more selected from compounds represented by 3X can be mentioned.
　前記量子ドットは、粒径が約２０ｎｍ以下の、結晶構造を有する無機ナノ粒子であり、量子サイズ効果の発現により、前記ペロブスカイト化合物とは異なる物性を示すものである。前記量子ドットは公知のものを特に制限なく用いることができるが、前記ペロブスカイト化合物が有しないバンドギャップエネルギーを補完して、近赤外光領域の光電変換効率を向上させる観点から、０．２ｅＶ以上前記ペロブスカイト化合物のバンドギャップエネルギー未満のバンドギャップエネルギーを有するものを用いることが好ましい。量子ドットは、１種単独で用いてもよく、バンドギャップエネルギーが異なる２種以上を併用してもよい。なお、バンドギャップエネルギーの異なる２種以上のペロブスカイト化合物を用いる場合、量子ドットのバンドギャップエネルギーの前記上限である「ペロブスカイト化合物のバンドギャップエネルギー未満のバンドギャップエネルギー」とは、２種以上のペロブスカイト化合物の有するバンドギャップエネルギーの最大値未満のバンドギャップエネルギーのことである。以下、特に断らない限り、量子ドットの好ましい態様は、光吸収層とその原料とに共通の好ましい態様である。 The quantum dots are inorganic nanoparticles having a crystal structure with a particle size of about 20 nm or less, and exhibit physical properties different from those of the perovskite compound due to the quantum size effect. As the quantum dot, known ones can be used without any particular limitation. It is preferable to use a compound having a bandgap energy less than that of the perovskite compound. A quantum dot may be used individually by 1 type, and may use together 2 or more types from which bandgap energy differs. When two or more perovskite compounds having different bandgap energies are used, the upper limit of the bandgap energy of the quantum dots, ie, "the bandgap energy less than the bandgap energy of the perovskite compound" means two or more perovskite compounds. is a bandgap energy that is less than the maximum bandgap energy possessed by . Hereinafter, unless otherwise specified, preferred aspects of quantum dots are preferred aspects common to the light absorbing layer and its raw material.
　前記量子ドットのバンドギャップエネルギーは、光電変換効率（電圧）を向上させる観点から、好ましくは０．６ｅＶ以上、より好ましくは０．７ｅＶ以上、更に好ましくは０．８ｅＶ以上であり、光電変換効率（電流）を向上させる観点から、好ましくは１．６ｅＶ以下、より好ましくは１．５ｅＶ以下、更に好ましくは１．４ｅＶ以下、更に好ましくは１．３ｅＶ以下である。 From the viewpoint of improving the photoelectric conversion efficiency (voltage), the bandgap energy of the quantum dots is preferably 0.6 eV or more, more preferably 0.7 eV or more, and still more preferably 0.8 eV or more. current), it is preferably 1.6 eV or less, more preferably 1.5 eV or less, even more preferably 1.4 eV or less, still more preferably 1.3 eV or less.
　前記量子ドットについては、例えば、電子顕微鏡観察、電子線回折、及びＸ線回折パターンなどにより量子ドットの粒径及び種類が決まれば、粒径とバンドギャップエネルギーとの相関（例えば、ＡＣＳ　Ｎａｎｏ，２０１４，８，６３６３－６３７１）から、バンドギャップエネルギーを算出することもできる。 Regarding the quantum dots, for example, if the particle size and type of quantum dots are determined by electron microscope observation, electron beam diffraction, X-ray diffraction pattern, etc., the correlation between particle size and bandgap energy (eg, ACS Nano, 2014 , 8, 6363-6371), the bandgap energy can also be calculated.
　前記ペロブスカイト化合物のバンドギャップエネルギーと前記量子ドットのバンドギャップエネルギーとの差は、光電変換効率向上の観点から、好ましくは０．４ｅＶ以上、より好ましくは０．８ｅＶ以上、更に好ましくは１．０ｅＶ以上、更に好ましくは１．２ｅＶ以上であり、好ましくは２．８ｅＶ以下、より好ましくは２．０ｅＶ以下、更に好ましくは１．６ｅＶ以下、更に好ましくは１．４ｅＶ以下である。 The difference between the bandgap energy of the perovskite compound and the bandgap energy of the quantum dots is preferably 0.4 eV or more, more preferably 0.8 eV or more, and still more preferably 1.0 eV or more, from the viewpoint of improving photoelectric conversion efficiency. , more preferably 1.2 eV or more, preferably 2.8 eV or less, more preferably 2.0 eV or less, still more preferably 1.6 eV or less, still more preferably 1.4 eV or less.
　前記量子ドットの粒径は、量子効果を発現する粒径であれば特に制限されるものではないが、分散性、構造安定性及び光電変換効率を向上させる観点から、好ましくは１ｎｍ以上、より好ましくは２ｎｍ以上、更に好ましくは３ｎｍ以上であり、好ましくは２０ｎｍ以下、より好ましくは１０ｎｍ以下、更に好ましくは５ｎｍ以下である。前記量子ドットの粒径は、ＸＲＤ（Ｘ線回折）の結晶子径解析や透過型電子顕微鏡観察などの常法によって測定することができる。 The particle size of the quantum dots is not particularly limited as long as it exhibits a quantum effect, but from the viewpoint of improving dispersibility, structural stability and photoelectric conversion efficiency, it is preferably 1 nm or more, more preferably. is 2 nm or more, more preferably 3 nm or more, preferably 20 nm or less, more preferably 10 nm or less, and still more preferably 5 nm or less. The particle size of the quantum dots can be measured by conventional methods such as XRD (X-ray diffraction) crystallite size analysis and transmission electron microscope observation.
　前記バンドギャップエネルギーを有する量子ドットとしては、例えば、金属酸化物、金属カルコゲナイド（例えば、硫化物、セレン化物、及びテルル化物など）が挙げられ、具体的には、ＰｂＳ、ＰｂＳｅ、ＰｂＴｅ、ＣｄＳ、ＣｄＳｅ、ＣｄＴｅ、Ｓｂ2Ｓ3、Ｂｉ2Ｓ3、Ａｇ2Ｓ、Ａｇ2Ｓｅ、Ａｇ2Ｔｅ、Ａｕ2Ｓ、Ａｕ2Ｓｅ、Ａｕ2Ｔｅ、Ｃｕ2Ｓ、Ｃｕ2Ｓｅ、Ｃｕ2Ｔｅ、Ｆｅ2Ｓ、Ｆｅ2Ｓｅ、Ｆｅ2Ｔｅ、Ｉｎ2Ｓ3、ＳｎＳ、ＳｎＳｅ、ＳｎＴｅ、ＣｕＩｎＳ2、ＣｕＩｎＳｅ2、ＣｕＩｎＴｅ2、ＥｕＳ、ＥｕＳｅ、及びＥｕＴｅなどが挙げられる。前記量子ドットは、耐久性（耐酸化性）及び光電変換効率に優れる観点から、好ましくはＰｂ元素を含み、より好ましくはＰｂＳ又はＰｂＳｅを含み、更に好ましくはＰｂＳを含む。 Examples of quantum dots having the bandgap energy include metal oxides, metal chalcogenides (e.g., sulfides, selenides, tellurides, etc.), and specific examples include PbS, PbSe, PbTe, CdS, CdSe, CdTe, Sb2S3 , Bi2S3 , Ag2S , Ag2Se , Ag2Te, Au2S , Au2Se , Au2Te , Cu2S, Cu2Se , Cu2Te , Fe2S , Fe2Se , Fe2Te , In2S3 , SnS, SnSe, SnTe, CuInS2 , CuInSe2 , CuInTe2 , EuS, EuSe , and EuTe. From the viewpoint of excellent durability (oxidation resistance) and photoelectric conversion efficiency, the quantum dots preferably contain a Pb element, more preferably PbS or PbSe, and still more preferably PbS.
　前記量子ドットは、光吸収層及び分散液中における分散性、製造容易性、コスト、優れた性能発現などの観点から、配位子を有する。配位子は特に制限されず、例えば、有機化合物及びハロゲン含有物質から選ばれる１種以上が挙げられ、有機化合物及びハロゲン含有物質の両方であってもよい。光電変換効率を向上する観点から、ハロゲン含有物質を含むことが好ましい。 The quantum dots have ligands from the viewpoint of dispersibility in the light absorption layer and dispersion liquid, ease of production, cost, and excellent performance. The ligand is not particularly limited, and may be, for example, one or more selected from organic compounds and halogen-containing substances, and may be both organic compounds and halogen-containing substances. From the viewpoint of improving the photoelectric conversion efficiency, it preferably contains a halogen-containing substance.
　配位子である前記有機化合物（以下、有機配位子ともいう）としては、例えば、カルボキシ基含有化合物、アミノ基含有化合物、カルボキシ基とアミノ基を含有する化合物、チオール基含有化合物、及びホスフィノ基含有化合物などが挙げられる。 Examples of the organic compound that is a ligand (hereinafter also referred to as an organic ligand) include a carboxy group-containing compound, an amino group-containing compound, a compound containing a carboxy group and an amino group, a thiol group-containing compound, and phosphino group-containing compounds, and the like.
　カルボキシ基含有化合物としては、例えば、オレイン酸、ステアリン酸、パルミチン酸、ミリスチン酸、ラウリン酸、及びカプリン酸などが挙げられる。尚、カルボキシ基含有化合物は、カルボキシ基とアミノ基を含有する化合物を除く。 Examples of carboxy group-containing compounds include oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid. The carboxy group-containing compound excludes compounds containing a carboxy group and an amino group.
　アミノ基含有化合物としては、例えば、オレイルアミン、ステアリルアミン、パルミチルアミン、ミリスチルアミン、ラウリルアミン、カプリルアミン、オクチルアミン、ヘキシルアミン、及びブチルアミンなどが挙げられる。尚、アミノ基含有化合物は、カルボキシ基とアミノ基を含有する化合物を除く。 Examples of amino group-containing compounds include oleylamine, stearylamine, palmitylamine, myristylamine, laurylamine, caprylamine, octylamine, hexylamine, and butylamine. Amino group-containing compounds exclude compounds containing a carboxy group and an amino group.
　カルボキシ基とアミノ基を含有する化合物としては、例えば、脂肪族アミノ酸が挙げられ、前記脂肪族アミノ酸は、直鎖アミノ酸であってもよく、分岐鎖アミノ酸であってもよい。なお、本発明において、直鎖アミノ酸とは、炭素鎖の構造が直鎖状である脂肪族アミノ酸をいい、分岐鎖アミノ酸とは、炭素鎖の構造が分岐鎖状である脂肪族アミノ酸をいう。 Compounds containing a carboxy group and an amino group include, for example, aliphatic amino acids, and the aliphatic amino acids may be straight-chain amino acids or branched-chain amino acids. In the present invention, the term "linear amino acid" refers to an aliphatic amino acid having a linear carbon chain structure, and the term "branched chain amino acid" refers to an aliphatic amino acid having a branched carbon chain structure.
　前記脂肪族アミノ酸の炭素数は、光吸収層中のキャリア移動速度を向上させて光電変換効率を向上させる観点、及び量子ドット間の距離を小さくして、ペロブスカイト化合物のマトリクス中に前記量子ドットを高密度に分散させる観点から、好ましくは１０以下、より好ましくは８以下、更に好ましくは７以下であり、分散液中での分散性確保の観点から、好ましくは２以上、より好ましくは３以上である。 The number of carbon atoms in the aliphatic amino acid is selected from the viewpoint of improving the carrier transfer rate in the light absorption layer to improve the photoelectric conversion efficiency, and from the viewpoint of reducing the distance between the quantum dots so that the quantum dots are arranged in the matrix of the perovskite compound. From the viewpoint of high-density dispersion, it is preferably 10 or less, more preferably 8 or less, and still more preferably 7 or less, and from the viewpoint of ensuring dispersibility in the dispersion, preferably 2 or more, more preferably 3 or more. be.
　前記脂肪族アミノ酸のアミノ基は、炭素鎖中のいずれの炭素と結合していてもよいが、量子ドット表面に前記脂肪族アミノ酸を配位させやすくして、光吸収層及び分散液中における前記量子ドットの分散性を向上させる観点から、第一級炭素と結合していることが好ましい。 The amino group of the aliphatic amino acid may be bonded to any carbon in the carbon chain, but the aliphatic amino acid can be easily coordinated to the surface of the quantum dot, and the From the viewpoint of improving the dispersibility of the quantum dots, it is preferably bonded to primary carbon.
　チオール基含有化合物としては、例えば、エタンチオール、エタンジチオール、ベンゼンチオール、ベンゼンジチオール、デカンチオール、デカンジチオール、及びメルカプトプロピオン酸などが挙げられる。 Examples of thiol group-containing compounds include ethanethiol, ethanedithiol, benzenethiol, benzenedithiol, decanethiol, decanedithiol, and mercaptopropionic acid.
　ホスフィノ基含有化合物としては、例えば、トリオクチルホスフィン、及びトリブチルホスフィンなどが挙げられる。 Examples of phosphino group-containing compounds include trioctylphosphine and tributylphosphine.
　前記有機配位子は、量子ドットの製造容易性、分散性、汎用性、コスト、優れた性能発現などの観点から、好ましくはカルボキシ基含有化合物、アミノ基含有化合物、又はカルボキシ基とアミノ基を含有する化合物、より好ましくはカルボキシ基含有化合物又はアミノ基含有化合物、更に好ましくはカルボン酸、更に好ましくは脂肪酸、更に好ましくは炭素数８以上３０以下の脂肪酸、更に好ましくは炭素数１２以上１８以下の脂肪酸、更に好ましくは炭素数１２以上１８以下の不飽和脂肪酸、更に好ましくはオレイン酸である。 The organic ligand is preferably a carboxy group-containing compound, an amino group-containing compound, or a combination of a carboxy group and an amino group, from the viewpoint of ease of production of quantum dots, dispersibility, versatility, cost, and excellent performance expression. containing compound, more preferably a carboxy group-containing compound or an amino group-containing compound, more preferably a carboxylic acid, more preferably a fatty acid, still more preferably a fatty acid having 8 to 30 carbon atoms, still more preferably a fatty acid having 12 to 18 carbon atoms Fatty acids, more preferably unsaturated fatty acids having 12 to 18 carbon atoms, more preferably oleic acid.
　配位子である前記ハロゲン含有物質のハロゲンは特に制限されず、例えば、フッ素、塩素、臭素、及びヨウ素が挙げられる。前記ハロゲンは、量子ドットの製造容易性、分散性、汎用性、コスト、優れた性能発現などの観点から、好ましくはヨウ素又は臭素であり、より好ましくはヨウ素である。 The halogen of the halogen-containing substance that is a ligand is not particularly limited, and examples include fluorine, chlorine, bromine, and iodine. The halogen is preferably iodine or bromine, more preferably iodine, from the viewpoints of ease of production, dispersibility, versatility, cost, and excellent performance of quantum dots.
　配位子である前記ハロゲン含有物質としては、例えば、ヨウ素、ヨウ化アンモニウム、ヨウ化メチルアンモニウムなどが挙げられ、量子ドットの製造容易性、分散性、汎用性、コスト、優れた性能発現などの観点から、好ましくはハロゲン、より好ましくはヨウ素である。 Examples of the halogen-containing substance, which is a ligand, include iodine, ammonium iodide, and methylammonium iodide. From the point of view, halogen is preferred, and iodine is more preferred.
　前記ペロブスカイト化合物と前記量子ドットの好ましい組み合わせとしては、量子ドットの均一分散性、耐久性、及び光電変換効率の観点から、好ましくは同じ金属元素を含む化合物の組み合わせであり、例えば、ＣＨ３ＮＨ３ＰｂＢｒ３とＰｂＳ、ＣＨ３ＮＨ３ＰｂＢｒ３とＰｂＳｅ、ＣＨ（＝ＮＨ）ＮＨ３ＰｂＢｒ３とＰｂＳ、ＣＨ（＝ＮＨ）ＮＨ３ＰｂＢｒ３とＰｂＳｅなどが挙げられ、より好ましくはＣＨ３ＮＨ３ＰｂＢｒ３とＰｂＳとの組み合わせである。 A preferred combination of the perovskite compound and the quantum dots is a combination of compounds containing the same metal element, for example, CH 3 NH 3 , from the viewpoint of uniform dispersibility, durability, and photoelectric conversion efficiency of the quantum dots. PbBr3 and PbS, CH3NH3PbBr3 and PbSe , CH( = NH) NH3PbBr3 and PbS, CH(=NH) NH3PbBr3 and PbSe, more preferably CH3NH3PbBr 3 and PbS.
　前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩は、アミノ基及びカルボキシ基を有する有機化合物と水素酸との塩である。前記有機化合物は、アミノ基及びカルボキシ基をそれぞれ２以上有していてもよい。前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩は、１種用いてもよく、２種以上を併用してもよい。また、前記アミノ基及びカルボキシ基を有する有機化合物と前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩と併用してもよい。前記アミノ基及びカルボキシ基を有する有機化合物の溶解性の観点から、水素酸塩を含むことが好ましい。 The hydrochloride of an organic compound having an amino group and a carboxy group is a salt of an organic compound having an amino group and a carboxy group and hydrogen acid. The organic compound may have two or more amino groups and two or more carboxy groups. The hydrochloride of the organic compound having an amino group and a carboxy group may be used singly or in combination of two or more. Moreover, the above-mentioned organic compound having an amino group and a carboxyl group and the hydrochloride of the above-mentioned organic compound having an amino group and a carboxyl group may be used in combination. From the viewpoint of the solubility of the organic compound having an amino group and a carboxyl group, it preferably contains a hydrochloride.
　前記アミノ基及びカルボキシ基を有する有機化合物は特に制限されず、例えば、脂肪族アミノ酸及び芳香族アミノ酸から選ばれる１種以上が挙げられ、溶解性の観点から、好ましくは脂肪族アミノ酸である。前記脂肪族アミノ酸及び芳香族アミノ酸は特に制限されない。前記脂肪族アミノ酸は、直鎖アミノ酸であってもよく、分岐鎖アミノ酸であってもよいが、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは直鎖アミノ酸である。 The organic compound having an amino group and a carboxy group is not particularly limited, and includes, for example, one or more selected from aliphatic amino acids and aromatic amino acids, preferably aliphatic amino acids from the viewpoint of solubility. The aliphatic amino acids and aromatic amino acids are not particularly limited. The aliphatic amino acid may be a linear amino acid or a branched chain amino acid, but from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer, it is preferable. is a straight chain amino acid.
　前記アミノ基及びカルボキシ基を有する有機化合物の炭素数は、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは１８以下、より好ましくは１０以下、更に好ましくは８以下であり、また、好ましくは２以上、より好ましくは３以上、更に好ましくは４以上であり、また、好ましくは２以上１８以下、より好ましくは３以上１８以下、更に好ましくは３以上１０以下、更に好ましくは４以上８以下である。
　前記アミノ基及びカルボキシ基を有する有機化合物が芳香族アミノ酸である場合、炭素数は、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは１８以下、より好ましくは１０以下、更に好ましくは８以下であり、また、好ましくは７以上、より好ましくは８以上であり、また、好ましくは７以上１８以下、より好ましくは７以上１０以下、更に好ましくは７以上８以下である。 The number of carbon atoms in the organic compound having an amino group and a carboxy group is preferably 18 or less, more preferably 10 or less, from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer. More preferably 8 or less, more preferably 2 or more, more preferably 3 or more, still more preferably 4 or more, more preferably 2 or more and 18 or less, more preferably 3 or more and 18 or less, still more preferably 3 10 or less, more preferably 4 or more and 8 or less.
When the organic compound having an amino group and a carboxyl group is an aromatic amino acid, the number of carbon atoms is preferably 18 or less from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer. , more preferably 10 or less, more preferably 8 or less, preferably 7 or more, more preferably 8 or more, preferably 7 or more and 18 or less, more preferably 7 or more and 10 or less, still more preferably It is 7 or more and 8 or less.
　前記アミノ基及びカルボキシ基を有する有機化合物のアミノ基は、炭素鎖中のいずれの炭素と結合していてもよいが、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、第一級炭素と結合していることが好ましい。 The amino group of the organic compound having an amino group and a carboxy group may be bonded to any carbon in the carbon chain, but the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer From the viewpoint of improvement, it is preferably bonded to a primary carbon.
　前記水素酸とは、酸素を含まない酸であり、例えば、塩酸、フッ化水素酸、臭化水素酸、及びヨウ化水素酸などのハロゲン化水素酸、硫化水素酸、シアン化水素酸、並びにアジ化水素酸などの二元酸；テトラクロロ金(III)酸（ＨＡｕＣｌ４）、ヘキサクロロ白金(IV)酸（Ｈ２ＰｔＣｌ６）、及びテトラフルオロホウ酸（ＨＢＦ４）などのハロゲノ酸が挙げられる。 The hydroacid is an oxygen-free acid, for example, hydrohalic acid such as hydrochloric acid, hydrofluoric acid, hydrobromic acid and hydroiodic acid, hydrosulfic acid, hydrocyanic acid, and azide Binary acids such as hydroacid; halogenoacids such as tetrachloroauric ( III) acid ( HAuCl4 ), hexachloroplatinic(IV) acid ( H2PtCl6 ), and tetrafluoroboric acid ( HBF4 ).
　前記水素酸は、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくはハロゲン化水素酸、より好ましくは臭化水素酸である。 From the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light absorbing layer, the hydroacid is preferably hydrohalic acid, more preferably hydrobromic acid.
　前記アミノ基及びカルボキシ基を有する有機化合物としては、例えば、アミノプロパン酸、アミノブタン酸、アミノペンタン酸、アミノヘキサン酸、アミノヘプタン酸、アミノデカン酸、アミノオクタデカン酸、アミノフェニル酢酸、アミノ安息香酸等が挙げられ、アミノプロパン酸、アミノブタン酸、アミノペンタン酸、アミノヘキサン酸、アミノヘプタン酸、アミノフェニル酢酸、及びアミノ安息香酸から選ばれる１種以上が好ましい。
　前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩としては、例えば、アミノブタン酸・ハロゲン化水素酸塩、アミノペンタン酸・ハロゲン化水素酸塩、アミノヘキサン酸・ハロゲン化水素酸塩、及びアミノヘプタン酸・ハロゲン化水素酸塩(以上、「脂肪族アミノ酸のハロゲン化水素酸塩」)、アミノフェニル酢酸・ハロゲン化水素酸塩、及びアミノ安息香酸・ハロゲン化水素酸塩(以上、「芳香族アミノ酸のハロゲン化水素酸塩」)から選ばれる１種以上が好ましく挙げられ、分散液及び光吸収層中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは３－アミノプロパン酸、４－アミノブタン酸・臭化水素酸塩、５－アミノペンタン酸・臭化水素酸塩、６－アミノヘキサン酸・臭化水素酸塩、及び７－アミノヘプタン酸・臭化水素酸塩、４－アミノ安息香酸・臭化水素酸塩等、４－アミノフェニル酢酸・臭化水素酸塩である。これらは、１種用いてもよく、２種以上を併用してもよい。
　従って、溶解性の観点、分散安定性を向上させる観点から、脂肪族アミノ酸の水素酸塩又は芳香族の水素酸塩が好ましく、脂肪族アミノ酸のハロゲン化水素酸塩又は芳香族アミノ酸のハロゲン化水素酸塩がより好ましく、脂肪族アミノ酸のハロゲン化水素酸塩が更に好ましい。 Examples of the organic compound having an amino group and a carboxy group include aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminodecanoic acid, aminooctadecanoic acid, aminophenylacetic acid, aminobenzoic acid, and the like. and preferably one or more selected from aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminophenylacetic acid, and aminobenzoic acid.
Examples of the hydrochloride of an organic compound having an amino group and a carboxy group include aminobutanoic acid/hydrohalide, aminopentanoic acid/hydrohalide, aminohexanoic acid/hydrohalide, and amino Heptanoic acid/hydrohalide (above, “aliphatic amino acid hydrohalide”), aminophenylacetic acid/hydrohalide, and aminobenzoic acid/hydrohalide (above, “aromatic One or more selected from amino acid hydrohalides") are preferable, and from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion and the light-absorbing layer, preferably 3-aminopropane acids, 4-aminobutanoic acid hydrobromide, 5-aminopentanoic acid hydrobromide, 6-aminohexanoic acid hydrobromide, and 7-aminoheptanoic acid hydrobromide, and 4-aminophenylacetic acid hydrobromide, such as 4-aminobenzoic acid hydrobromide. These may be used singly or in combination of two or more.
Therefore, from the viewpoint of solubility and the viewpoint of improving dispersion stability, aliphatic amino acid hydrochloride or aromatic hydrochloride is preferable, aliphatic amino acid hydrohalide or aromatic amino acid hydrogen halide Acid salts are more preferred, and hydrohalide salts of aliphatic amino acids are even more preferred.
　分散液中の前記ペロブスカイト化合物及び／又はその前駆体の濃度は、光吸収層中のペロブスカイト化合物の含有量を増加させて、太陽電池の光電変換効率を向上させる観点から、好ましくは０．１ｍｏｌ／ｄｍ３以上、より好ましくは０．３ｍｏｌ／ｄｍ３以上、更に好ましくは０．５ｍｏｌ／ｄｍ３以上、より更に好ましくは０．７ｍｏｌ／ｄｍ３以上であり、分散液中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは３ｍｏｌ／ｄｍ３以下、より好ましくは２ｍｏｌ／ｄｍ３以下、更に好ましくは１．５ｍｏｌ／ｄｍ３以下、より更に好ましくは１ｍｏｌ／ｄｍ３以下であり、また、前記観点から、好ましくは０．１ｍｏｌ／ｄｍ３以上３ｍｏｌ／ｄｍ３以下、より好ましくは０．３ｍｏｌ／ｄｍ３以上２ｍｏｌ／ｄｍ３以下、更に好ましくは０．３ｍｏｌ／ｄｍ３以上１．５ｍｏｌ／ｄｍ３以下、より更に好ましくは０．５ｍｏｌ／ｄｍ３以上１ｍｏｌ／ｄｍ３以下、より更に好ましくは０．７ｍｏｌ／ｄｍ３以上１ｍｏｌ／ｄｍ３以下である。 The concentration of the perovskite compound and/or its precursor in the dispersion is preferably 0.1 mol/mol/mol from the viewpoint of increasing the content of the perovskite compound in the light absorbing layer and improving the photoelectric conversion efficiency of the solar cell. dm 3 or more, more preferably 0.3 mol/dm 3 or more, still more preferably 0.5 mol/dm 3 or more, still more preferably 0.7 mol/dm 3 or more, and the dispersibility of the quantum dots in the dispersion And from the viewpoint of improving dispersion stability, it is preferably 3 mol/dm 3 or less, more preferably 2 mol/dm 3 or less, still more preferably 1.5 mol/dm 3 or less, still more preferably 1 mol/dm 3 or less, From the above viewpoint, it is preferably 0.1 mol/dm 3 or more and 3 mol/dm 3 or less, more preferably 0.3 mol/dm 3 or more and 2 mol/dm 3 or less, still more preferably 0.3 mol/dm 3 or more and 1.5 mol. /dm 3 or less, more preferably 0.5 mol/dm 3 or more and 1 mol/dm 3 or less, still more preferably 0.7 mol/dm 3 or more and 1 mol/dm 3 or less.
　分散液中の前記ペロブスカイト化合物及び／又はその前駆体の含有量及び配合量は、太陽電池の光電変換効率を向上させる観点から、好ましくは５質量％以上、より好ましくは１０質量％以上、更に好ましくは１５質量％以上であり、分散安定性を向上させる観点から、好ましくは５０質量％以下、より好ましくは４０質量％以下、更に好ましくは３０質量％以下であり、また、前記観点から、好ましくは５質量％以上５０質量％以下、より好ましくは１０質量％以上４０質量％以下、更に好ましくは１５質量％以上３０質量％以下である。 The content and amount of the perovskite compound and/or its precursor in the dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably, from the viewpoint of improving the photoelectric conversion efficiency of the solar cell. is 15% by mass or more, and from the viewpoint of improving dispersion stability, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less, and even more preferably 15% by mass or more and 30% by mass or less.
　分散液中の前記量子ドットの含有量及び配合量は、太陽電池の光電変換効率を向上させる観点から、好ましくは１質量％以上、より好ましくは３質量％以上、更に好ましくは５質量％以上であり、分散安定性を向上させる観点から、好ましくは４０質量％以下、より好ましくは３０質量％以下、更に好ましくは２０質量％以下であり、また、前記観点から、好ましくは１質量％以上４０質量％以下、より好ましくは３質量％以上３０質量％以下、更に好ましくは５質量％以上２０質量％以下である。 From the viewpoint of improving the photoelectric conversion efficiency of the solar cell, the content and amount of the quantum dots in the dispersion are preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more. From the viewpoint of improving dispersion stability, it is preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less, and from the above viewpoint, preferably 1% by mass or more and 40% by mass. %, more preferably 3% to 30% by mass, and even more preferably 5% to 20% by mass.
　分散液中の前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩の含有量及び配合量は、分散安定性を向上させる観点から、好ましくは０．０１質量％以上、より好ましくは０．０３質量％以上、更に好ましくは０．１質量％以上であり、製造コスト低減、及び、光電変換効率を向上する観点から、好ましくは２０質量％以下、より好ましくは１０質量％以下、更に好ましくは５質量％以下であり、また、前記観点から、好ましくは０．０１質量％以上２０質量％以下、より好ましくは０．０３質量％以上１０質量％以下、更に好ましくは０．１質量％以上５質量％以下である。尚、前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩とは、前記アミノ基及びカルボキシ基を有する有機化合物、前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩、前記アミノ基及びカルボキシ基を有する有機化合物と前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩の合計のいずれであってもよい。 The content and blending amount of the organic compound having an amino group and a carboxy group and/or a hydrochloride thereof in the dispersion is preferably 0.01% by mass or more, more preferably 0.01% by mass or more, more preferably 0.03% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of reducing manufacturing costs and improving photoelectric conversion efficiency, preferably 20% by mass or less, more preferably 10% by mass or less, and further It is preferably 5% by mass or less, and from the above viewpoint, preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.03% by mass or more and 10% by mass or less, and still more preferably 0.1% by mass. It is more than 5 mass % or less. The organic compound having an amino group and a carboxyl group and/or a hydride thereof means the organic compound having an amino group and a carboxyl group, the hydride of an organic compound having an amino group and a carboxyl group, the amino and a carboxy group-containing organic compound and the hydrochloride salt of the above-mentioned organic compound having an amino group and a carboxy group.
　分散液中の前記量子ドット（ただし、配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の合計質量比（前記有機化合物とその水素酸塩の合計の質量／前記量子ドットの質量）は、分散液中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは０．００１以上、より好ましくは０．００３以上、更に好ましくは０．０１以上、より更に好ましくは０．０３以上であり、製造コスト低減、及び、光電変換効率を向上する観点から、好ましくは５以下、より好ましくは３以下、更に好ましくは１．５以下、更に好ましくは１．１以下、更に好ましくは０．８以下、更に好ましくは０．５以下、更に好ましくは０．４以下、更に好ましくは０．２以下、更に好ましくは０．１以下であり、また、前記観点から、好ましくは０．００１以上５以下、より好ましくは０．００３以上１．５以下、更に好ましくは０．０１以上１．１以下、より更に好ましくは０．０３以上０．８以下である。 The total mass ratio of the organic compound having an amino group and a carboxy group and its hydride (total of the organic compound and its hydride The mass of / the mass of the quantum dot) is preferably 0.001 or more, more preferably 0.003 or more, and still more preferably 0 from the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion liquid. 0.01 or more, more preferably 0.03 or more, and from the viewpoint of reducing manufacturing costs and improving photoelectric conversion efficiency, it is preferably 5 or less, more preferably 3 or less, even more preferably 1.5 or less, and further is preferably 1.1 or less, more preferably 0.8 or less, still more preferably 0.5 or less, still more preferably 0.4 or less, still more preferably 0.2 or less, still more preferably 0.1 or less, and , From the above viewpoint, preferably 0.001 to 5, more preferably 0.003 to 1.5, still more preferably 0.01 to 1.1, still more preferably 0.03 to 0.8 is.
　また、分散液中の前記量子ドット（配位子を含む）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の合計質量比（前記有機化合物とその水素酸塩の合計質量／前記量子ドットの質量）の好ましい値も上記と同じである。本明細書中、特に言及しない場合、量子ドットは配位子を含めて計算する。 In addition, the total mass ratio of the organic compound having an amino group and a carboxyl group and its hydride to the quantum dots (including ligands) in the dispersion (total mass of the organic compound and its hydride / the The preferred value of the quantum dot mass) is also the same as above. In this specification, quantum dots are calculated including ligands unless otherwise specified.
　分散液中の前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比〔前記量子ドット／（前記ペロブスカイト化合物及び／又はその前駆体）〕は、光吸収層中の量子ドットの含有割合を増加させて、太陽電池の光電変換効率を向上させる観点から、好ましくは０．１以上、より好ましくは０．２以上、更に好ましくは０．３以上、より更に好ましくは０．４以上であり、分散液中における前記量子ドットの分散性及び分散安定性を向上させる観点から、好ましくは３以下、より好ましくは２以下、更に好ましくは１以下、より更に好ましくは０．７以下であり、また、前記観点から、好ましくは０．１以上３以下、より好ましくは０．２以上２以下、更に好ましくは０．２以上１以下、更に好ましくは０．３以上１以下、更に好ましくは０．３以上０．７以下、更に好ましくは０．４以上０．７以下である。 The mass ratio of the quantum dots to the perovskite compound and/or its precursor in the dispersion [the quantum dots/(the perovskite compound and/or its precursor)] is the content ratio of the quantum dots in the light absorption layer. is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and even more preferably 0.4 or more, from the viewpoint of increasing the photoelectric conversion efficiency of the solar cell by increasing the From the viewpoint of improving the dispersibility and dispersion stability of the quantum dots in the dispersion, it is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, and even more preferably 0.7 or less, and From the above viewpoint, it is preferably 0.1 or more and 3 or less, more preferably 0.2 or more and 2 or less, still more preferably 0.2 or more and 1 or less, still more preferably 0.3 or more and 1 or less, still more preferably 0.3 or more. It is 0.7 or less, more preferably 0.4 or more and 0.7 or less.
　前記分散液は、成膜性、コスト、保存安定性、優れた性能（例えば、光電変換特性）発現の観点から、好ましくは溶剤を含有する。溶剤としては、例えば、エステル類（メチルホルメート、エチルホルメートなど）、ケトン類（γ－ブチロラクトン、Ｎ－メチル－２－ピロリドン、アセトン、ジメチルケトン、ジイソブチルケトンなど）、エーテル類（ジエチルエーテル、メチル－ｔｅｒｔ－ブチルエーテル、ジメトキシメタン、１，４－ジオキサン、テトラヒドロフランなど）、アルコール類（メタノール、エタノール、２－プロパノール、ｔｅｒｔ－ブタノール、メトキシプロパノール、ジアセトンアルコール、シクロヘキサノール、２－フルオロエタノール、２，２，２－トリフルオロエタノール、２，２，３，３－テトラフルオロ－１－プロパノールなど）、グリコールエーテル(セロソルブ)類、アミド系溶剤（Ｎ，Ｎ－ジメチルホルムアミド、アセトアミド、Ｎ，Ｎ－ジメチルアセトアミドなど）、ニトリル系溶剤（アセトニトリル、イソブチロニトリル、プロピオニトリル、メトキシアセトニトリルなど）、カーボネート系（エチレンカーボネート、プロピレンカーボネートなど）、ハロゲン化炭化水素（塩化メチレン、ジクロロメタン、クロロホルムなど）、炭化水素、及びジメチルスルホキシドなどが挙げられる。 The dispersion liquid preferably contains a solvent from the viewpoint of film-forming properties, cost, storage stability, and excellent performance (for example, photoelectric conversion characteristics). Examples of solvents include esters (methyl formate, ethyl formate, etc.), ketones (γ-butyrolactone, N-methyl-2-pyrrolidone, acetone, dimethyl ketone, diisobutyl ketone, etc.), ethers (diethyl ether, methyl-tert-butyl ether, dimethoxymethane, 1,4-dioxane, tetrahydrofuran, etc.), alcohols (methanol, ethanol, 2-propanol, tert-butanol, methoxypropanol, diacetone alcohol, cyclohexanol, 2-fluoroethanol, 2 , 2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, etc.), glycol ethers (cellosolve), amide solvents (N,N-dimethylformamide, acetamide, N,N- dimethylacetamide, etc.), nitrile solvents (acetonitrile, isobutyronitrile, propionitrile, methoxyacetonitrile, etc.), carbonates (ethylene carbonate, propylene carbonate, etc.), halogenated hydrocarbons (methylene chloride, dichloromethane, chloroform, etc.), hydrocarbons, dimethylsulfoxide, and the like.
　前記分散液の溶剤は、成膜性、コスト、保存安定性、優れた性能（例えば、光電変換特性）発現の観点から、好ましくは極性溶剤、より好ましくはケトン類、アミド系溶剤、及びジメチルスルホキシドから選ばれる少なくとも１種の溶剤、更に好ましくはアミド系溶剤、更に好ましくはＮ，Ｎ－ジメチルホルムアミドである。 The solvent for the dispersion liquid is preferably a polar solvent, more preferably ketones, an amide solvent, and dimethyl sulfoxide, from the viewpoint of film forming properties, cost, storage stability, and excellent performance (e.g., photoelectric conversion characteristics). at least one solvent selected from, more preferably an amide solvent, more preferably N,N-dimethylformamide.
＜光吸収層の製造方法＞
　前記光吸収層の製造方法は特に制限されず、例えば、前記分散液を基板上に塗布し、乾燥する、いわゆるウエットプロセスによる方法が好適に挙げられる。製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、次の工程１、工程２及び工程３を含む製造方法が好ましい。
（工程１）有機配位子を含む量子ドット固体を得る工程、又は前記有機配位子を、ハロゲン含有物質へ配位子交換して、ハロゲン含有物質を配位子として含む量子ドット固体を得る工程
（工程２）工程１で得られた量子ドット固体と、ペロブスカイト化合物およびその前駆体から選ばれる１種以上の物質を含む溶液又は混合液と、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩とを混合して前記分散液を得る工程
（工程３）工程２で得られた前記分散液から光吸収層を得る工程 <Method for producing light absorbing layer>
A method for producing the light absorption layer is not particularly limited, and a preferred example thereof is a so-called wet process method in which the dispersion is applied onto a substrate and dried. A manufacturing method including the following steps 1, 2, and 3 is preferred from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like.
(Step 1) Step of obtaining a quantum dot solid containing an organic ligand, or ligand exchange of the organic ligand with a halogen-containing substance to obtain a quantum dot solid containing a halogen-containing substance as a ligand Step (Step 2) A solution or mixture containing the quantum dot solid obtained in Step 1, one or more substances selected from perovskite compounds and precursors thereof, an organic compound having an amino group and a carboxyl group, and/or a step of obtaining the dispersion by mixing with the hydrochloride (step 3) a step of obtaining a light absorbing layer from the dispersion obtained in step 2;
　有機配位子を含む量子ドット固体の該有機配位子を、ハロゲン含有物質へ配位子交換して、ハロゲン含有物質を配位子として含む量子ドット固体を得る工程（工程１）は、前記分散液の分散性を向上させる観点、及び光吸収層中のキャリア移動速度を向上させて光電変換効率を向上させる観点から好ましい。 The step (step 1) of obtaining a quantum dot solid containing a halogen-containing substance as a ligand by exchanging the organic ligand of the quantum dot solid containing the organic ligand with a halogen-containing substance (step 1) It is preferable from the viewpoint of improving the dispersibility of the dispersion liquid and from the viewpoint of improving the photoelectric conversion efficiency by improving the carrier moving speed in the light absorbing layer.
　一般に、量子ドットの粒径制御、凝集抑制、分散性向上などのために、オレイン酸などの比較的分子サイズが大きく疎水的な有機化合物を配位子として用いて量子ドットが合成される場合がある。この場合、量子ドットは、トルエンなどの非（低）極性有機溶媒に対しては優れた分散性を示すが、Ｎ，Ｎ－ジメチルホルムアミド、メタノールなどの極性有機溶媒に対して分散性は悪い。従って、ペロブスカイト化合物及び／又はその前駆体を分散又は溶解させる溶媒が極性有機溶媒である場合、量子ドットを極性有機溶媒に分散させる必要が有り、極性有機溶媒と相溶性の高い物質を量子ドットに配位させることが好ましい。また、オレイン酸などの比較的分子サイズが大きく疎水的な有機化合物は、導電性が低く光吸収層中のキャリアの拡散を阻害する。従って、光吸収層中のキャリア移動速度を向上させ光電変換効率を向上させる観点から、比較的分子サイズの小さい物質を量子ドットに配位させることが好ましい。以上の観点から、量子ドットの配位子としては、好ましくはヨウ素、ヨウ化アンモニウム、ヨウ化メチルアンモニウム、臭素、臭化アンモニウム、及び臭化メチルアンモニウムなどから選択される1種以上のハロゲン含有物質が挙げられ、より好ましくはヨウ素又は臭素であり、更に好ましくはヨウ素である。 In general, in order to control the particle size of quantum dots, suppress aggregation, and improve dispersibility, quantum dots are sometimes synthesized using organic compounds with relatively large molecular sizes and hydrophobicity, such as oleic acid, as ligands. be. In this case, quantum dots exhibit excellent dispersibility in non-(low) polar organic solvents such as toluene, but poor dispersibility in polar organic solvents such as N,N-dimethylformamide and methanol. Therefore, when the solvent for dispersing or dissolving the perovskite compound and/or its precursor is a polar organic solvent, it is necessary to disperse the quantum dots in the polar organic solvent. Coordination is preferred. In addition, a hydrophobic organic compound having a relatively large molecular size, such as oleic acid, has low conductivity and inhibits diffusion of carriers in the light absorption layer. Therefore, from the viewpoint of improving the carrier transfer speed in the light absorption layer and improving the photoelectric conversion efficiency, it is preferable to coordinate the quantum dots with a substance having a relatively small molecular size. From the above viewpoints, the ligand of the quantum dot is preferably one or more halogen-containing substances selected from iodine, ammonium iodide, methylammonium iodide, bromine, ammonium bromide, and methylammonium bromide. and more preferably iodine or bromine, and still more preferably iodine.
　有機配位子を含む量子ドットの該有機配位子をハロゲン含有物質へ配位子交換する方法としては、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、分散液中で配位子交換する方法が好ましく、有機配位子を含む量子ドット分散液とハロゲン含有物質の原料溶液とを室温（２５℃）、無撹拌下、時間をかけて混合後、静置することにより、配位子交換する方法がより好ましい。 As a method for ligand exchange of the organic ligand of the quantum dot containing the organic ligand to the halogen-containing substance, from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc. A method of exchanging ligands in a dispersion is preferred, and a quantum dot dispersion containing an organic ligand and a raw material solution of a halogen-containing substance are mixed at room temperature (25 ° C.) without stirring over a period of time, and then allowed to stand still. A method of exchanging ligands by placing is more preferable.
　配位子交換に使用するハロゲン含有物質の原料としては、ヨウ化メチルアンモニウム（メチルアミンヨウ化水素酸塩）、ヨウ化アンモニウム、ヨウ素、臭化メチルアンモニウム（メチルアミン臭化水素酸塩）、臭化アンモニウム、及び臭素などが好適に挙げられるが、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくはヨウ化メチルアンモニウム（メチルアミンヨウ化水素酸塩）、ヨウ化アンモニウム、臭化メチルアンモニウム（メチルアミン臭化水素酸塩）、及び臭化アンモニウムから選択される１種以上、より好ましくはヨウ化メチルアンモニウム（メチルアミンヨウ化水素酸塩）、及び臭化メチルアンモニウム（メチルアミンヨウ化水素酸塩）から選択される１種以上、更に好ましくはヨウ化メチルアンモニウム（メチルアミンヨウ化水素酸塩）である。 Raw materials for halogen-containing substances used for ligand exchange include methylammonium iodide (methylamine hydroiodide), ammonium iodide, iodine, methylammonium bromide (methylamine hydrobromide), bromine Ammonium chloride, bromine, and the like are preferably mentioned, but from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., methylammonium iodide (methylamine hydroiodide) is preferable. , ammonium iodide, methylammonium bromide (methylamine hydrobromide), and one or more selected from ammonium bromide, more preferably methylammonium iodide (methylamine hydroiodide), and bromine One or more selected from methylammonium iodide (methylamine hydroiodide), more preferably methylammonium iodide (methylamine hydroiodide).
　配位子交換に使用するハロゲン含有物質原料の混合量は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、量子ドット表面の有機化合物に対するハロゲンのモル比として、好ましくは０．１以上、より好ましくは１以上、更に好ましくは１．５以上であり、好ましくは１０以下、より好ましくは８以下、更に好ましくは５以下、更に好ましくは３以下である。 From the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., the mixed amount of the halogen-containing substance raw material used for ligand exchange is determined as the molar ratio of halogen to the organic compound on the surface of the quantum dots. , preferably 0.1 or more, more preferably 1 or more, still more preferably 1.5 or more, preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, still more preferably 3 or less.
　配位子交換に使用する溶媒としては、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは量子ドットを良好に分散させる溶媒とハロゲン含有物質原料を溶解させる溶媒との混合溶媒である。量子ドットの分散溶媒は、好ましくはトルエン、ヘキサン、及びオクタンなどから選択される１種以上の非（低）極性有機溶媒、より好ましくはトルエンである。ハロゲン含有物質原料の溶解溶媒は、好ましくはＮ，Ｎ－ジメチルホルムアミド、ジメチルスルホキシド、及びγ－ブチロラクトンなどから選択される１種以上の非プロトン性極性有機溶媒、より好ましくはＮ，Ｎ－ジメチルホルムアミドである。 From the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., the solvent used for ligand exchange is preferably a solvent that disperses the quantum dots well and a halogen-containing substance raw material. It is a mixed solvent with a solvent that allows The dispersion solvent for the quantum dots is preferably one or more non-(low) polar organic solvents selected from toluene, hexane, octane, etc., more preferably toluene. The dissolving solvent for the halogen-containing substance raw material is preferably one or more aprotic polar organic solvents selected from N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, etc., more preferably N,N-dimethylformamide. is.
　配位子交換時に混合する量子ドット分散液中の量子ドット固形分濃度は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは１０ｍｇ／ｍＬ以上、より好ましくは５０ｍｇ／ｍＬ以上、更に好ましくは８０ｍｇ／ｍＬ以上であり、好ましくは１０００ｍｇ／ｍＬ以下、より好ましくは５００ｍｇ／ｍＬ以下、更に好ましくは２００ｍｇ／ｍＬ以下、更に好ましくは１２０ｍｇ／ｍＬ以下である。 The quantum dot solid content concentration in the quantum dot dispersion mixed during ligand exchange is preferably 10 mg / mL or more, from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc. It is preferably 50 mg/mL or more, more preferably 80 mg/mL or more, preferably 1000 mg/mL or less, more preferably 500 mg/mL or less, still more preferably 200 mg/mL or less, still more preferably 120 mg/mL or less.
　配位子交換時に混合するハロゲン含有物質原料溶液中のハロゲン含有物質原料濃度は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは０．０１ｍｏｌ／Ｌ以上、より好ましくは０．１ｍｏｌ／Ｌ以上、更に好ましくは０．２ｍｏｌ／Ｌ以上であり、好ましくは１ｍｏｌ／Ｌ以下、より好ましくは０．５ｍｏｌ／Ｌ以下、更に好ましくは０．３ｍｏｌ／Ｌ以下である。 The concentration of the halogen-containing substance raw material in the halogen-containing substance raw material solution mixed during ligand exchange is preferably 0.01 mol/L from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. Above, more preferably 0.1 mol/L or more, still more preferably 0.2 mol/L or more, preferably 1 mol/L or less, more preferably 0.5 mol/L or less, still more preferably 0.3 mol/L or less is.
　配位子交換時の量子ドット分散液とハロゲン含有物質原料溶液との混合方法は、無撹拌下で、時間を掛けて混合する方法であれば特に限定されるものではないが、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは連続法又は滴下法（半連続法）、より好ましくは滴下法である。 The method of mixing the quantum dot dispersion and the raw material solution of the halogen-containing substance at the time of ligand exchange is not particularly limited as long as it is a method of mixing for a long time under no stirring. From the viewpoints of cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., the continuous method or the dropping method (semi-continuous method) is preferred, and the dropping method is more preferred.
　連続法としては、量子ドット分散液にハロゲン含有物質原料溶液を混合する方法でも、ハロゲン含有物質原料溶液に量子ドット分散液を混合する方法でも良いが、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、量子ドット分散液にハロゲン含有物質原料溶液を混合する方法が好ましい。混合速度は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは２５μＬ／秒以下、より好ましくは５μＬ／秒以下、更に好ましくは３μＬ／秒以下であり、好ましくは０．２μＬ／秒以上、より好ましくは０．４μＬ／秒以上、更に好ましくは１．５μＬ／秒以上である。 As a continuous method, a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion or a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion may be used. From the viewpoints of properties, improvement of photoelectric conversion efficiency, etc., a method of mixing a halogen-containing substance raw material solution with a quantum dot dispersion is preferable. The mixing speed is preferably 25 µL/sec or less, more preferably 5 µL/sec or less, and still more preferably 3 µL/sec or less from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. , preferably 0.2 μL/sec or more, more preferably 0.4 μL/sec or more, and still more preferably 1.5 μL/sec or more.
　滴下法としては、量子ドット分散液にハロゲン含有物質原料溶液を滴下する方法でも、ハロゲン含有物質原料溶液に量子ドット分散液を滴下する方法でも良いが、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、量子ドット分散液にハロゲン含有物質原料溶液を滴下する方法が好ましい。滴下速度は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは１滴／１秒以下、より好ましくは１滴／５秒以下、更に好ましくは１滴／８秒以下であり、好ましくは１滴／１００秒以上、より好ましくは１滴／５０秒以上、更に好ましくは１滴／１５秒以上である。 As the dropping method, a method of dropping the halogen-containing substance raw material solution into the quantum dot dispersion or a method of dropping the quantum dot dispersion into the halogen-containing substance raw material solution may be used. From the viewpoint of improving the properties and photoelectric conversion efficiency, the method of dropping the halogen-containing material raw material solution into the quantum dot dispersion is preferable. The dropping rate is preferably 1 drop/second or less, more preferably 1 drop/5 seconds or less, and still more preferably 1 drop, from the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. /8 sec or less, preferably 1 drop/100 sec or more, more preferably 1 drop/50 sec or more, and still more preferably 1 drop/15 sec or more.
　量子ドット分散液とハロゲン含有物質原料溶液とを混合後、静置する時間は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、好ましくは０．１時間以上、より好ましくは１時間以上、更に好ましくは１０時間以上であり、好ましくは１００時間以下、より好ましくは４８時間以下、更に好ましくは２４時間以下である。 After the quantum dot dispersion and the halogen-containing substance raw material solution are mixed, the time for standing still is preferably 0.1 hour or more from the viewpoint of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like. , more preferably 1 hour or more, still more preferably 10 hours or more, preferably 100 hours or less, more preferably 48 hours or less, still more preferably 24 hours or less.
　配位子交換後、有機化合物とハロゲン含有物質とを配位子とする量子ドット固体を得る方法としては、量子ドット分散液とハロゲン含有物質原料溶液との混合分散液に洗浄溶媒を添加し、ろ過して、量子ドット表面に配位していた有機化合物や過剰のハロゲン含有物質原料、溶媒を除去する工程を経て、量子ドット固体を得る方法が好ましい。洗浄溶媒は、配位子交換前後のいずれの量子ドットも分散しにくく、且つ、有機化合物、ハロゲン含有物質が可溶な有機溶媒が好ましく、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、より好ましくはアルコール溶媒、更に好ましくはメタノールである。洗浄溶媒の量は、量子ドット分散液とハロゲン含有物質原料溶液との混合分散液の量に対する洗浄溶媒の体積比として、好ましくは０．１以上、より好ましくは０．５以上、更に好ましくは１以上であり、好ましくは１０以下、より好ましくは５以下、更に好ましくは２以下である。製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、ろ過時のフィルター孔径は、好ましくは０．１μｍ以上、より好ましくは０．２μｍ以上であり、好ましくは１μｍ以下、より好ましくは０．５μｍ以下である。フィルター材質は、好ましくは疎水性のもの、より好ましくはポリテトラフルオロエチレン（ＰＴＦＥ）である。 After ligand exchange, as a method of obtaining a quantum dot solid having an organic compound and a halogen-containing substance as ligands, a washing solvent is added to a mixed dispersion of a quantum dot dispersion and a halogen-containing substance raw material solution, A preferred method is to obtain a quantum dot solid through a step of filtering to remove the organic compound coordinated to the quantum dot surface, excess halogen-containing raw material, and solvent. The washing solvent is preferably an organic solvent in which the quantum dots before and after ligand exchange are difficult to disperse and in which organic compounds and halogen-containing substances are soluble. From the viewpoint of improving the conversion efficiency, more preferably an alcohol solvent, still more preferably methanol. The amount of the washing solvent is preferably 0.1 or more, more preferably 0.5 or more, and still more preferably 1 as a volume ratio of the washing solvent to the mixed dispersion of the quantum dot dispersion and the halogen-containing material raw material solution. or more, preferably 10 or less, more preferably 5 or less, and still more preferably 2 or less. From the viewpoints of ease of production, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, etc., the filter pore size at the time of filtration is preferably 0.1 μm or more, more preferably 0.2 μm or more, and preferably 1 μm or less. , and more preferably 0.5 μm or less. The filter material is preferably hydrophobic, more preferably polytetrafluoroethylene (PTFE).
　工程１で得られた量子ドット固体と、ペロブスカイト化合物及びその前駆体から選ばれる１種以上の物質を含む溶液又は混合液と、アミノ基及びカルボキシ基を有する有機化合物の水素酸塩とを混合する工程（工程２）を経て、ペロブスカイト化合物及びその前駆体から選ばれる１種以上と、前記配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩とを含む分散液を得ることが好ましい。 A solution or mixture containing the quantum dot solid obtained in step 1, one or more substances selected from perovskite compounds and their precursors, and a hydrochloride of an organic compound having an amino group and a carboxy group are mixed. Through the step (step 2), one or more selected from perovskite compounds and precursors thereof, quantum dots having the ligand, and an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof are prepared. It is preferred to obtain a dispersion comprising
　工程２で得られた分散液から光吸収層を得る工程（工程３）は、工程２で得られた分散液を基板（機能層）上に塗布（コーティング）するなどのウエットプロセスが好ましく、例えば、グラビア塗布法、バー塗布法、印刷法、スプレー法、スピンコーティング法、ディップ法、及びダイコート法などが挙げられ、製造容易性、コスト、優れた性能（例えば、光電変換特性）発現の観点から、好ましくはスピンコーティング法である。スピンコーティング法におけるスピンコーターの最大回転数は、優れた性能（例えば、光電変換特性）発現の観点から、好ましくは５００ｒｐｍ以上、より好ましくは１０００ｒｐｍ以上、更に好ましくは２０００ｒｐｍ以上であり、好ましくは８０００ｒｐｍ以下、より好ましくは７０００ｒｐｍ以下、更に好ましくは６０００ｒｐｍ以下である。 The step (step 3) of obtaining a light absorbing layer from the dispersion obtained in step 2 is preferably a wet process such as coating the substrate (functional layer) with the dispersion obtained in step 2. For example, , gravure coating method, bar coating method, printing method, spray method, spin coating method, dip method, and die coating method, etc., from the viewpoint of ease of production, cost, excellent performance (e.g., photoelectric conversion characteristics) expression , preferably a spin coating method. The maximum rotation speed of the spin coater in the spin coating method is preferably 500 rpm or more, more preferably 1000 rpm or more, still more preferably 2000 rpm or more, and preferably 8000 rpm or less, from the viewpoint of expressing excellent performance (e.g., photoelectric conversion characteristics). , more preferably 7000 rpm or less, still more preferably 6000 rpm or less.
　また、製造容易性、コスト、及び光電変換特性向上などの観点から、前記分散液を基板上に塗布した後にペロブスカイト化合物の貧溶媒を塗布又は滴下してペロブスカイト化合物の結晶析出速度を向上させてもよい。前記貧溶媒は、好ましくはトルエン、クロロベンゼン、ジクロロメタン、又はこれらの混合溶媒である。 From the viewpoint of ease of manufacture, cost, improvement of photoelectric conversion characteristics, etc., a poor solvent for the perovskite compound may be applied or dropped after the dispersion is applied onto the substrate to improve the perovskite compound crystal precipitation rate. good. The poor solvent is preferably toluene, chlorobenzene, dichloromethane, or a mixed solvent thereof.
　前記ウエットプロセスにおける乾燥方法としては、製造容易性、コスト、優れた性能（例えば、光電変換特性）発現などの観点から、例えば、熱乾燥、気流乾燥、真空乾燥などが挙げられ、好ましくは熱乾燥である。熱乾燥の温度は、優れた性能（例えば、光電変換特性）発現の観点から、好ましくは６０℃以上、より好ましくは８０℃以上、更に好ましくは９０℃以上であり、同様の観点及びコストの観点から、好ましくは２００℃以下、より好ましくは１５０℃以下、更に好ましくは１２０℃以下、更に好ましくは１１０℃以下である。熱乾燥の時間は、優れた性能（例えば、光電変換特性）発現の観点から、好ましくは１分以上、より好ましくは５分以上、更に好ましくは８分以上であり、同様の観点及びコストの観点から、好ましくは１２０分以下、より好ましくは６０分以下、更に好ましくは２０分以下、更に好ましくは１２分以下である。 The drying method in the wet process includes, for example, heat drying, airflow drying, vacuum drying, etc., preferably heat drying, from the viewpoint of ease of production, cost, and expression of excellent performance (e.g., photoelectric conversion characteristics). is. The temperature for thermal drying is preferably 60° C. or higher, more preferably 80° C. or higher, and still more preferably 90° C. or higher from the viewpoint of expressing excellent performance (e.g., photoelectric conversion characteristics). Therefore, the temperature is preferably 200° C. or lower, more preferably 150° C. or lower, still more preferably 120° C. or lower, and still more preferably 110° C. or lower. The heat drying time is preferably 1 minute or more, more preferably 5 minutes or more, and still more preferably 8 minutes or more from the viewpoint of exhibiting excellent performance (e.g., photoelectric conversion characteristics), from the same viewpoint and cost viewpoint. Therefore, the time is preferably 120 minutes or less, more preferably 60 minutes or less, still more preferably 20 minutes or less, still more preferably 12 minutes or less.
＜光吸収層＞
　本発明の光吸収層は、前記ペロブスカイト化合物と、前記配位子を有する量子ドットと、前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する。なお、本発明の光吸収層は、本発明の効果を損なわない範囲で前記以外の光吸収剤を含有してもよい。 <Light absorption layer>
The light-absorbing layer of the present invention contains the perovskite compound, the quantum dot having the ligand, and the organic compound having the amino group and the carboxy group and/or the hydride thereof. The light-absorbing layer of the invention may contain light-absorbing agents other than those described above as long as the effects of the invention are not impaired.
　本発明の光吸収層は、中間バンドを有してもよい。中間バンドとは、ペロブスカイト化合物のバンドギャップ内に量子ドット間の相互作用により形成されるエネルギー準位であり、量子ドットの伝導帯下端近傍及び／又は価電子帯上端近傍のエネルギー位置に存在する。中間バンドは、例えば、ペロブスカイト化合物のマトリクス中に量子ドットを高密度に規則配列することにより形成される。ペロブスカイト化合物のバンドギャップ内に中間バンドが存在すると、例えば、ペロブスカイト化合物の価電子帯から中間バンドへ光励起した電子が、更に中間バンドからペロブスカイト化合物の伝導帯へ光励起するといった２段階光吸収が起こる。従って、中間バンドの存在は、２段階光吸収の量子収率、すなわち、外部量子収率差を測定することにより確認することができる。 The light absorption layer of the present invention may have an intermediate band. The intermediate band is an energy level formed by interactions between quantum dots within the bandgap of the perovskite compound, and exists at energy positions near the lower end of the conduction band and/or the upper end of the valence band of the quantum dots. The intermediate band is formed, for example, by regularly arranging quantum dots in a perovskite compound matrix at high density. If an intermediate band exists within the band gap of the perovskite compound, for example, two-step light absorption occurs, in which electrons photoexcited from the valence band of the perovskite compound to the intermediate band are further photoexcited from the intermediate band to the conduction band of the perovskite compound. Therefore, the presence of the intermediate band can be confirmed by measuring the quantum yield of the two-step light absorption, that is, the external quantum yield difference.
　光吸収層のペロブスカイト化合物の結晶子径は、キャリアの移動効率を向上させて光電変換効率を向上させる観点から、好ましくは１０ｎｍ以上、より好ましくは２０ｎｍ以上、更に好ましくは３０ｎｍ以上、更に好ましくは４０ｎｍ以上であり、同様の観点から、好ましくは１０００ｎｍ以下である。 The crystallite diameter of the perovskite compound in the light absorption layer is preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm or more, and even more preferably 40 nm, from the viewpoint of improving the carrier transfer efficiency and photoelectric conversion efficiency. From the same point of view, the thickness is preferably 1000 nm or less.
　光吸収層のペロブスカイト化合物は、例えば、元素分析、赤外（ＩＲ）スペクトル、ラマンスペクトル、核磁気共鳴（ＮＭＲ）スペクトル、Ｘ線回折パターン、吸収スペクトル、発光スペクトル、電子顕微鏡観察、及び電子線回折などの常法により同定することができる。 The perovskite compound of the light-absorbing layer is analyzed, for example, by elemental analysis, infrared (IR) spectrum, Raman spectrum, nuclear magnetic resonance (NMR) spectrum, X-ray diffraction pattern, absorption spectrum, emission spectrum, electron microscope observation, and electron beam diffraction. It can be identified by a conventional method such as.
　光吸収層の量子ドットは、例えば、元素分析、赤外（ＩＲ）スペクトル、ラマンスペクトル、核磁気共鳴（ＮＭＲ）スペクトル、Ｘ線回折パターン、吸収スペクトル、発光スペクトル、小角Ｘ線散乱、電子顕微鏡観察、及び電子線回折などの常法により同定することができる。 Quantum dots in the light-absorbing layer are, for example, elemental analysis, infrared (IR) spectrum, Raman spectrum, nuclear magnetic resonance (NMR) spectrum, X-ray diffraction pattern, absorption spectrum, emission spectrum, small angle X-ray scattering, electron microscope observation , and electron beam diffraction.
　光吸収層中の量子ドットの含有量は、量子ドットを高密度に充填することにより量子ドット間距離を小さくして量子ドット間で相互作用させることにより光吸収層中に中間バンドを形成し、２段階光吸収の量子収率を向上させる観点から、好ましく５ｖｏｌ％以上、より好ましくは７．５ｖｏｌ％以上、更に好ましくは１０ｖｏｌ％以上、より更に好ましくは１２ｖｏｌ％以上であり、成膜性と、ペロブスカイト化合物から量子ドットへのキャリア移動を抑制し光電変換効率を向上させる観点から、好ましくは４０ｖｏｌ％以下、より好ましくは３０ｖｏｌ％以下、更に好ましくは２５ｖｏｌ％以下であり、また、前記観点から、好ましくは５ｖｏｌ％以上４０ｖｏｌ％以下、より好ましくは７．５ｖｏｌ％以上３０ｖｏｌ％以下、更に好ましくは１０ｖｏｌ％以上２５ｖｏｌ％以下、より更に好ましくは１２ｖｏｌ％以上２５ｖｏｌ％以下である。なお、光吸収層中の量子ドットの含有量とは、ペロブスカイト化合物と配位子を有する量子ドットの合計体積に対する配位子を有する量子ドットの体積割合を意味する。 The content of quantum dots in the light absorption layer is such that the quantum dots are densely packed to reduce the distance between the quantum dots and interact between the quantum dots to form an intermediate band in the light absorption layer, From the viewpoint of improving the quantum yield of two-stage light absorption, it is preferably 5 vol% or more, more preferably 7.5 vol% or more, still more preferably 10 vol% or more, and still more preferably 12 vol% or more. It is preferably 40 vol% or less, more preferably 30 vol% or less, still more preferably 25 vol% or less from the viewpoint of suppressing carrier transfer from the perovskite compound to the quantum dots and improving the photoelectric conversion efficiency. is 5 vol% or more and 40 vol% or less, more preferably 7.5 vol% or more and 30 vol% or less, still more preferably 10 vol% or more and 25 vol% or less, still more preferably 12 vol% or more and 25 vol% or less. The content of quantum dots in the light absorption layer means the volume ratio of quantum dots having ligands to the total volume of quantum dots having perovskite compounds and ligands.
　光吸収層の厚さは特に制限されないが、光吸収を大きくして光電変換効率を向上させる観点から、好ましくは３０ｎｍ以上、より好ましくは５０ｎｍ以上、更に好ましくは８０ｎｍ以上であり、正孔輸送剤層や電子輸送剤層へのキャリア移動効率を向上させて光電変換効率を向上させる観点から、好ましくは１０００ｎｍ以下、より好ましくは８００ｎｍ以下、更に好ましくは６００ｎｍ以下、更に好ましくは５００ｎｍ以下である。なお、光吸収層の厚さは、膜断面の電子顕微鏡観察などの測定方法で測定できる。 Although the thickness of the light absorption layer is not particularly limited, it is preferably 30 nm or more, more preferably 50 nm or more, and still more preferably 80 nm or more from the viewpoint of increasing light absorption and improving photoelectric conversion efficiency. It is preferably 1000 nm or less, more preferably 800 nm or less, still more preferably 600 nm or less, still more preferably 500 nm or less from the viewpoint of improving the photoelectric conversion efficiency by improving the carrier transfer efficiency to the layer or the electron transport agent layer. Note that the thickness of the light absorbing layer can be measured by a measuring method such as electron microscope observation of a film cross section.
＜光電変換素子＞
　本発明の光電変換素子は、前記光吸収層を有するものである。本発明の光電変換素子において、前記光吸収層以外の構成は、公知の光電変換素子の構成を適用することができる。また、本発明の光電変換素子は、前記光吸収層以外は公知の方法で製造することができる。 <Photoelectric conversion element>
The photoelectric conversion element of the present invention has the light absorption layer. In the photoelectric conversion device of the present invention, the configuration of a known photoelectric conversion device can be applied to the configuration other than the light absorption layer. Moreover, the photoelectric conversion element of the present invention can be manufactured by a known method except for the light absorption layer.
　以下、本発明の光電変換素子の構成と製造方法を図１に基づいて説明するが、図１は一例にすぎず、図１に示す態様に限定されるものではない。 The configuration and manufacturing method of the photoelectric conversion element of the present invention will be described below with reference to FIG. 1, but FIG. 1 is only an example and is not limited to the embodiment shown in FIG.
　図１は、本発明の光電変換素子の構造の一例を示す概略断面図である。光電変換素子１は、透明基板２、透明導電層３、ブロッキング層４、多孔質層５、光吸収層６、及び正孔輸送層７が順次積層された構造を有する。光１０入射側の透明電極基板は、透明基板２と透明導電層３から構成されており、透明導電層３は外部回路と電気的につなげるための端子となる電極（負極）９に接合している。また、正孔輸送層７は外部回路と電気的につなげるための端子となる電極（正極）８に接合している。 FIG. 1 is a schematic cross-sectional view showing an example of the structure of the photoelectric conversion element of the present invention. The photoelectric conversion element 1 has a structure in which a transparent substrate 2, a transparent conductive layer 3, a blocking layer 4, a porous layer 5, a light absorption layer 6, and a hole transport layer 7 are sequentially laminated. The transparent electrode substrate on the incident side of the light 10 is composed of a transparent substrate 2 and a transparent conductive layer 3, and the transparent conductive layer 3 is joined to an electrode (negative electrode) 9 serving as a terminal for electrical connection with an external circuit. there is Further, the hole transport layer 7 is joined to an electrode (positive electrode) 8 that serves as a terminal for electrical connection with an external circuit.
　透明基板２の材料としては、強度、耐久性、光透過性があればよく、合成樹脂及びガラスなどを使用できる。合成樹脂としては、例えば、ポリエチレンナフタレート（ＰＥＮ）フィルムなどの熱可塑性樹脂、ポリエチレンテレフタレート（ＰＥＴ）、ポリエステル、ポリカーボネート、ポリオレフィン、ポリイミド、及びフッ素樹脂などが挙げられる。強度、耐久性、コストなどの観点から、ガラス基板を用いることが好ましい。 As the material for the transparent substrate 2, it is sufficient that it has strength, durability, and light transmittance, and synthetic resin, glass, etc. can be used. Examples of synthetic resins include thermoplastic resins such as polyethylene naphthalate (PEN) film, polyethylene terephthalate (PET), polyesters, polycarbonates, polyolefins, polyimides, and fluorine resins. From the viewpoint of strength, durability, cost, etc., it is preferable to use a glass substrate.
　透明導電層３の材料としては、例えば、スズ添加酸化インジウム（ＩＴＯ）、フッ素添加酸化スズ（ＦＴＯ）、酸化スズ（ＳｎＯ2）、インジウム亜鉛酸化物（ＩＺＯ）、酸化亜鉛（ＺｎＯ）、及び高い導電性を有する高分子材料などが挙げられる。高分子材料としては、例えば、ポリアセチレン系、ポリピロール系、ポリチオフェン系、ポリフェニレンビニレン系の高分子材料が挙げられる。また、透明導電層３の材料として、高い導電性を有する炭素系薄膜を用いることもできる。透明導電層３の形成方法としては、スパッタ法、蒸着法、及び分散物を塗布する方法などが挙げられる。 Materials for the transparent conductive layer 3 include, for example, tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide (SnO 2 ), indium zinc oxide (IZO), zinc oxide (ZnO), and high Examples thereof include polymer materials having electrical conductivity. Examples of polymer materials include polyacetylene-based, polypyrrole-based, polythiophene-based, and polyphenylenevinylene-based polymer materials. Also, as the material of the transparent conductive layer 3, a carbon-based thin film having high conductivity can be used. Methods for forming the transparent conductive layer 3 include a sputtering method, a vapor deposition method, and a method of applying a dispersion.
　ブロッキング層４の材料としては、例えば、酸化チタン、酸化アルミ、酸化ケイ素、酸化ニオブ、酸化タングステン、酸化錫、及び酸化亜鉛などが挙げられる。ブロッキング層４の形成方法としては、上記材料を透明導電層３に直接スパッタする方法、及びスプレーパイロリシス法などが挙げられる。また、上記材料を溶媒に溶解した溶液、又は金属酸化物の前駆体である金属水酸化物を溶解した溶液を透明導電層３上に塗布し、乾燥し、必要に応じて焼成する方法が挙げられる。塗布方法としては、グラビア塗布法、バー塗布法、印刷法、スプレー法、スピンコーティング法、ディップ法、及びダイコート法などが挙げられる。 Examples of materials for the blocking layer 4 include titanium oxide, aluminum oxide, silicon oxide, niobium oxide, tungsten oxide, tin oxide, and zinc oxide. Methods of forming the blocking layer 4 include a method of directly sputtering the above material onto the transparent conductive layer 3, a spray pyrolysis method, and the like. Further, a method of applying a solution obtained by dissolving the above materials in a solvent or a solution obtained by dissolving a metal hydroxide, which is a precursor of a metal oxide, onto the transparent conductive layer 3, drying and, if necessary, baking. be done. Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
　多孔質層５は、その表面に光吸収層６を担持する機能を有する層である。太陽電池において光吸収効率を高めるためには、光を受ける部分の表面積を大きくすることが好ましい。多孔質層５を設けることにより、光を受ける部分の表面積を大きくすることができる。 The porous layer 5 is a layer having a function of supporting the light absorbing layer 6 on its surface. In order to increase the light absorption efficiency of a solar cell, it is preferable to increase the surface area of the portion that receives light. By providing the porous layer 5, the surface area of the portion that receives light can be increased.
　多孔質層５の材料としては、例えば、金属酸化物、金属カルコゲナイド（例えば、硫化物、及びセレン化物など）、ペロブスカイト型結晶構造を有する化合物（ただし、前記光吸収剤を除く）、ケイ素酸化物（例えば、二酸化ケイ素及びゼオライト）、及びカーボンナノチューブ（カーボンナノワイヤ及びカーボンナノロッドなどを含む）などが挙げられる。 Materials for the porous layer 5 include, for example, metal oxides, metal chalcogenides (e.g., sulfides, selenides, etc.), compounds having a perovskite crystal structure (excluding the light absorbers), and silicon oxides. (eg, silicon dioxide and zeolites), and carbon nanotubes (including carbon nanowires and carbon nanorods, etc.).
　金属酸化物としては、例えば、チタン、スズ、亜鉛、タングステン、ジルコニウム、ハフニウム、ストロンチウム、インジウム、セリウム、イットリウム、ランタン、バナジウム、ニオブ、アルミニウム、及びタンタルの酸化物などが挙げられ、金属カルコゲナイドとしては、例えば、硫化亜鉛、セレン化亜鉛、硫化カドミウム、及びセレン化カドミウムなどが挙げられる。 Examples of metal oxides include oxides of titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, aluminum, and tantalum. , such as zinc sulfide, zinc selenide, cadmium sulfide, and cadmium selenide.
　ペロブスカイト型結晶構造を有する化合物としては、例えば、チタン酸ストロンチウム、チタン酸カルシウム、チタン酸バリウム、チタン酸鉛、ジルコン酸バリウム、スズ酸バリウム、ジルコン酸鉛、ジルコン酸ストロンチウム、タンタル酸ストロンチウム、ニオブ酸カリウム、鉄酸ビスマス、チタン酸ストロンチウムバリウム、チタン酸バリウムランタン、チタン酸カルシウム、チタン酸ナトリウム、及びチタン酸ビスマスなどが挙げられる。 Examples of compounds having a perovskite crystal structure include strontium titanate, calcium titanate, barium titanate, lead titanate, barium zirconate, barium stannate, lead zirconate, strontium zirconate, strontium tantalate, and niobate. Potassium, bismuth ferrate, strontium barium titanate, barium lanthanum titanate, calcium titanate, sodium titanate, and bismuth titanate.
　多孔質層５の形成材料は、好ましくは微粒子として用いられ、より好ましくは微粒子を含有する分散物として用いられる。多孔質層５の形成方法としては、例えば、湿式法、乾式法、その他の方法（例えば、Ｃｈｅｍｉｃａｌ　Ｒｅｖｉｅｗ，第１１０巻，６５９５頁（２０１０年刊）に記載の方法）が挙げられる。これらの方法において、ブロッキング層４の表面に分散物（ペースト）を塗布した後に、焼成することが好ましい。焼成により、微粒子同士を密着させることができる。塗布方法としては、グラビア塗布法、バー塗布法、印刷法、スプレー法、スピンコーティング法、ディップ法、及びダイコート法などが挙げられる。 The material for forming the porous layer 5 is preferably used as fine particles, more preferably as a dispersion containing fine particles. Methods for forming the porous layer 5 include, for example, a wet method, a dry method, and other methods (for example, the method described in Chemical Review, Vol. 110, p. 6595 (published in 2010)). In these methods, it is preferable to apply the dispersion (paste) to the surface of the blocking layer 4 and then bake it. By firing, fine particles can be brought into close contact with each other. Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
　光吸収層６は前述の本発明の光吸収層である。光吸収層６の形成方法は特に制限されず、例えば、ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物の水素酸塩と、を含有する分散液を調製し、多孔質層５の表面に調製した分散液を塗布し、乾燥する、いわゆるウエットプロセスによる方法が好適に挙げられる。光吸収層６の形成方法は、製造容易性、コスト、分散液の保存安定性、光電変換効率向上などの観点から、前述の工程１、工程２及び工程３を含む製造方法が好ましい。 The light absorption layer 6 is the light absorption layer of the present invention described above. The method for forming the light absorption layer 6 is not particularly limited, and for example, a perovskite compound and/or a precursor thereof, quantum dots having ligands, and a hydrochloride of an organic compound having an amino group and a carboxy group are used. A preferred method is a so-called wet process in which a dispersion is prepared, the prepared dispersion is applied to the surface of the porous layer 5, and dried. The method of forming the light absorbing layer 6 is preferably a manufacturing method including the above-described steps 1, 2 and 3 from the viewpoints of ease of manufacture, cost, storage stability of the dispersion, improvement of photoelectric conversion efficiency, and the like.
　正孔輸送層７の材料としては、例えば、カルバゾール誘導体、ポリアリールアルカン誘導体、フェニレンジアミン誘導体、アリールアミン誘導体、アミノ置換カルコン誘導体、スチリルアントラセン誘導体、フルオレン誘導体、ヒドラゾン誘導体、スチルベン誘導体、シラザン誘導体、芳香族第三級アミン化合物、スチリルアミン化合物、芳香族ジメチリディン系化合物、ポルフィリン系化合物、フタロシアニン系化合物、ポリチオフェン誘導体、ポリピロール誘導体、及びポリパラフェニレンビニレン誘導体などが挙げられる。正孔輸送層７の形成方法としては、例えば、塗布法、及び真空蒸着法などが挙げられる。塗布方法としては、例えば、グラビア塗布法、バー塗布法、印刷法、スプレー法、スピンコーティング法、ディップ法、及びダイコート法などが挙げられる。 Materials for the hole transport layer 7 include, for example, carbazole derivatives, polyarylalkane derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorene derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic derivatives. tertiary amine compounds, styrylamine compounds, aromatic dimethylidine compounds, porphyrin compounds, phthalocyanine compounds, polythiophene derivatives, polypyrrole derivatives, and polyparaphenylenevinylene derivatives. Examples of the method for forming the hole transport layer 7 include a coating method and a vacuum deposition method. Examples of coating methods include gravure coating, bar coating, printing, spraying, spin coating, dipping, and die coating.
　電極（正極）８及び電極（負極）９の材料としては、例えば、アルミニウム、金、銀、白金などの金属；スズ添加酸化インジウム（ＩＴＯ）、インジウム亜鉛酸化物（ＩＺＯ）、酸化亜鉛（ＺｎＯ）などの導電性金属酸化物；導電性高分子などの有機系導電材料；ナノチューブなどの炭素系材料が挙げられる。電極（正極）８及び電極（負極）９の形成方法としては、例えば、真空蒸着法、スパッタリング法、及び塗布法などが挙げられる。 Materials for the electrode (positive electrode) 8 and the electrode (negative electrode) 9 include, for example, metals such as aluminum, gold, silver, and platinum; tin-added indium oxide (ITO), indium zinc oxide (IZO), and zinc oxide (ZnO). organic conductive materials such as conductive polymers; and carbon-based materials such as nanotubes. Methods for forming the electrode (positive electrode) 8 and the electrode (negative electrode) 9 include, for example, a vacuum vapor deposition method, a sputtering method, and a coating method.
＜太陽電池＞
　本発明の太陽電池は、前記光電変換素子を有するものである。本発明の太陽電池において、前記光吸収層以外の構成は特に制限されず、公知の太陽電池の構成を適用することができる。 <Solar cell>
The solar cell of the present invention has the photoelectric conversion element. In the solar cell of the present invention, the configuration other than the light absorption layer is not particularly limited, and known solar cell configurations can be applied.
　上述した実施形態に関し、本発明はさらに以下の態様を開示する。
［１］
　ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する又は配合してなる分散液。
［２］
　前記ペロブスカイト化合物は、下記一般式（１）で表される化合物及び下記一般式（２）で表される化合物から選ばれる１種以上である、［１］に記載の分散液。
　ＲＭＸ３　　　　（１）
（式中、Ｒは１価のカチオンであり、Ｍは２価の金属カチオンであり、Ｘはハロゲンアニオンである。）
　Ｒ１Ｒ２Ｒ３ ｎ－１ＭｎＸ３ｎ＋１　　　　（２）
（式中、Ｒ１、Ｒ２、及びＲ３はそれぞれ独立に１価のカチオンであり、Ｍは２価の金属カチオンであり、Ｘはハロゲンアニオンであり、ｎは１以上１０以下の整数である。）
［３］
　前記量子ドットが、金属カルコゲナイドを含む、［１］又は［２］に記載の分散液。
［４］
　前記アミノ基及びカルボキシ基を有する有機化合物は、脂肪族アミノ酸及び芳香族アミノ酸から選ばれる１種以上であり、好ましくは脂肪族アミノ酸である、［１］～［３］のいずれかに記載の分散液。
［５］
　前記水素酸塩は、ハロゲン化水素酸塩である、［１］～［４］のいずれかに記載の分散液。
［６］
　前記アミノ基及びカルボキシ基を有する有機化合物の炭素数は、２以上１８以下である、［１］～［５］のいずれかに記載の分散液。
［７］
　前記アミノ基及びカルボキシ基を有する有機化合物の炭素数は、３以上１０以下である、［１］～［６］のいずれかに記載の分散液。
［８］
　前記アミノ基及びカルボキシ基を有する有機化合物の炭素数は、４以上８以下である、［１］～［７］のいずれかに記載の分散液。
［９］
　前記アミノ基及びカルボキシ基を有する有機化合物は、アミノプロパン酸、アミノブタン酸、アミノペンタン酸、アミノヘキサン酸、アミノヘプタン酸、アミノフェニル酢酸、及びアミノ安息香酸から選ばれる１種以上である、［１］～［８］のいずれかに記載の分散液。
［１０］
　前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩は、脂肪族アミノ酸の水素酸塩又は芳香族アミノ酸の水素酸塩が好ましく、脂肪族アミノ酸のハロゲン化水素酸塩又は芳香族アミノ酸のハロゲン化水素酸塩がより好ましく、脂肪族アミノ酸のハロゲン化水素酸塩が更に好ましく、アミノブタン酸・ハロゲン化水素酸塩、アミノペンタン酸・ハロゲン化水素酸塩、アミノヘキサン酸・ハロゲン化水素酸塩、アミノヘプタン酸・ハロゲン化水素酸塩、アミノフェニル酢酸・ハロゲン化水素酸塩、及びアミノ安息香酸・ハロゲン化水素酸塩から選ばれる１種以上が更により好ましい、［１］～［７］のいずれかに記載の分散液。
［１１］
　前記配位子は、有機化合物及びハロゲン含有物質から選ばれる１種以上、好ましくはカルボキシ基含有化合物、アミノ基含有化合物及びハロゲン含有物質から選ばれる１種以上、より好ましくハロゲン含有物質を含む、［１］～［１０］のいずれかに記載の分散液。
［１２］
　前記配位子が、カルボキシ基含有化合物、アミノ基含有化合物、カルボキシ基とアミノ基を含有する化合物、チオール基含有化合物、及びホスフィノ基含有化合物から選ばれる１種以上を含む、［１］～［１０］のいずれかに記載の分散液。
［１３］
　前記配位子は、ハロゲンを含む、［１］～［１２］のいずれかに記載の分散液。
［１４］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．１ｍｏｌ／ｄｍ３以上である、［１］～［１３］のいずれかに記載の分散液。
［１５］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．１ｍｏｌ／ｄｍ３以上３ｍｏｌ／ｄｍ３以下である、［１］～［１４］のいずれかに記載の分散液。
［１６］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．３ｍｏｌ／ｄｍ３以上２ｍｏｌ／ｄｍ３以下である、［１］～［１５］のいずれかに記載の分散液。
［１７］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．３ｍｏｌ／ｄｍ３以上１．５ｍｏｌ／ｄｍ３以下である、［１］～［１６］のいずれかに記載の分散液。
［１８］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．５ｍｏｌ／ｄｍ３以上１ｍｏｌ／ｄｍ３以下である、［１］～［１７］のいずれかに記載の分散液。
［１９］
　分散液中、前記量子ドット（配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比（前記有機化合物とその水素酸塩の合計／前記量子ドット）が、０．００１以上である、［１］～［１８］のいずれかに記載の分散液。
［２０］
　分散液中、前記量子ドット（配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比（前記有機化合物とその水素酸塩の合計／前記量子ドット）が、０．００１以上５以下である、［１］～［１９］のいずれかに記載の分散液。
［２１］
　分散液中、前記量子ドット（配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比（前記有機化合物とその水素酸塩の合計／前記量子ドット）が、０．００３以上１．５以下である、［１］～［２０］のいずれかに記載の分散液。
［２２］
　分散液中、前記量子ドット（配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比（前記有機化合物とその水素酸塩の合計／前記量子ドット）が、０．０１以上１．１以下である、［１］～［２１］のいずれかに記載の分散液。
［２３］
　分散液中、前記量子ドット（配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比（前記有機化合物とその水素酸塩の合計／前記量子ドット）が、０．０３以上０．８以下である、［１］～［２２］のいずれかに記載の分散液。
［２４］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比〔前記量子ドット／（前記ペロブスカイト化合物及び／又はその前駆体）〕が、０．１以上である、［１］～［２３］のいずれかに記載の分散液。
［２５］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比〔前記量子ドット／（前記ペロブスカイト化合物及び／又はその前駆体）〕が、０．１以上３以下である、［１］～［２４］のいずれかに記載の分散液。
［２６］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比〔前記量子ドット／（前記ペロブスカイト化合物及び／又はその前駆体）〕が、０．２以上１以下である、［１］～［２５］のいずれかに記載の分散液。
［２７］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比〔前記量子ドット／（前記ペロブスカイト化合物及び／又はその前駆体）〕が、０．３以上０．７以下である、［１］～［２６］のいずれかに記載の分散液。
［２８］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の含有量又は配合量は、５質量％以上５０質量％以下である、［１］～［２７］のいずれかに記載の分散液。
［２９］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の含有量又は配合量は、１０質量％以上４０質量％以下である、［１］～［２８］のいずれかに記載の分散液。
［３０］
　分散液中、前記ペロブスカイト化合物及び／又はその前駆体の含有量又は配合量は、１５質量％以上３０質量％以下である、［１］～［２９］のいずれかに記載の分散液。
［３１］
　分散液中、前記量子ドットの含有量又は配合量は、１質量％以上４０質量％以下である、［１］～［３０］のいずれかに記載の分散液。
［３２］
　分散液中、前記量子ドットの含有量又は配合量は、３質量％以上３０質量％以下である、［１］～［３１］のいずれかに記載の分散液。
［３３］
　分散液中、前記量子ドットの含有量又は配合量は、５質量％以上２０質量％以下である、［１］～［３２］のいずれかに記載の分散液。
［３４］
　分散液中、前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩及び／又はその含有量又は配合量は、０．０１質量％以上２０質量％以下である、［１］～［３３］のいずれかに記載の分散液。
［３５］
　分散液中、前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩及び／又はその含有量又は配合量は、０．０３質量％以上１０質量％以下である、［１］～［３４］のいずれかに記載の分散液。
［３６］
　分散液中、前記アミノ基及びカルボキシ基を有する有機化合物の水素酸塩及び／又はその含有量又は配合量）は、０．１質量％以上５質量％以下である、［１］～［３５］のいずれかに記載の分散液。
［３７］
　光吸収層形成用である、［１］～［３６］のいずれかに記載の分散液。
［３８］
　［１］～［３７］のいずれかに記載の分散液から得られる光吸収層。
［３９］
　ペロブスカイト化合物と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する光吸収層。
［４０］
　前記アミノ基及びカルボキシ基を有する有機化合物は、脂肪族アミノ酸及び芳香族アミノ酸から選ばれる１種以上である、［３９］に記載の光吸収層。
［４１］
　前記水素酸塩は、ハロゲン化水素酸塩である、［３９］又は［４０］に記載の光吸収層。
［４２］
　前記配位子は、有機化合物及びハロゲン含有物質から選ばれる１種以上である、［３９］～［４１］のいずれかに記載の光吸収層。
［４３］
　光吸収層中の前記量子ドットの含有量が、５ｖｏｌ％以上である、［３９］～［４２］のいずれかに記載の光吸収層。
［４４］
　光吸収層中の前記量子ドットの含有量が、５ｖｏｌ％以上４０ｖｏｌ％以下である、［３９］～［４３］のいずれかに記載の光吸収層。
［４５］
　光吸収層中の前記量子ドットの含有量が、７．５ｖｏｌ％以上３０ｖｏｌ％以下である、［３９］～［４４］のいずれかに記載の光吸収層。
［４６］
　光吸収層中の前記量子ドットの含有量が、１０ｖｏｌ％以上２５ｖｏｌ％以下である、［３９］～［４５］のいずれかに記載の光吸収層。
［４７］
　光吸収層中の前記量子ドットの含有量が、１２ｖｏｌ％以上２５ｖｏｌ％以下である、［３９］～［４６］のいずれかに記載の光吸収層。
［４８］
　［３８］～［４７］のいずれかに記載の光吸収層を有する光電変換素子。
［４９］
　［４８］に記載の光電変換素子を有する太陽電池。
［５０］
　前記ペロブスカイト化合物及び／又はその前駆体と、前記配位子を有する量子ドットと、前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を混合する、［１］～［３６］のいずれかに記載の分散液の製造方法。 This invention discloses the following aspects further regarding embodiment mentioned above.
[1]
A dispersion containing or blending a perovskite compound and/or a precursor thereof, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof.
[2]
The dispersion according to [1], wherein the perovskite compound is one or more selected from compounds represented by the following general formula (1) and compounds represented by the following general formula (2).
RMX 3 (1)
(Wherein, R is a monovalent cation, M is a divalent metal cation, and X is a halogen anion.)
R 1 R 2 R 3 n−1 M n X 3n+1 (2)
(Wherein, R 1 , R 2 , and R 3 are each independently a monovalent cation, M is a divalent metal cation, X is a halogen anion, and n is an integer of 1 or more and 10 or less. be.)
[3]
The dispersion liquid according to [1] or [2], wherein the quantum dots contain a metal chalcogenide.
[4]
The dispersion according to any one of [1] to [3], wherein the organic compound having an amino group and a carboxy group is one or more selected from aliphatic amino acids and aromatic amino acids, preferably an aliphatic amino acid. liquid.
[5]
The dispersion according to any one of [1] to [4], wherein the hydrochloride is a hydrohalide.
[6]
The dispersion according to any one of [1] to [5], wherein the organic compound having an amino group and a carboxy group has 2 or more and 18 or less carbon atoms.
[7]
The dispersion according to any one of [1] to [6], wherein the organic compound having an amino group and a carboxy group has 3 or more and 10 or less carbon atoms.
[8]
The dispersion according to any one of [1] to [7], wherein the organic compound having an amino group and a carboxy group has 4 or more and 8 or less carbon atoms.
[9]
The organic compound having an amino group and a carboxy group is at least one selected from aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminophenylacetic acid, and aminobenzoic acid. ] to [8].
[10]
The hydrochloride of an organic compound having an amino group and a carboxy group is preferably an aliphatic amino acid hydrochloride or an aromatic amino acid hydrochloride, and an aliphatic amino acid hydrohalide or an aromatic amino acid halogenation. Hydrochlorides are more preferred, and aliphatic amino acid hydrohalides are even more preferred. One or more selected from heptanoic acid/hydrohalide, aminophenylacetic acid/hydrohalide, and aminobenzoic acid/hydrohalide are more preferable, any of [1] to [7] The dispersion described in .
[11]
[ 1] to the dispersion liquid according to any one of [10].
[12]
[1] to [1] to [1] to [1] to [ 10].
[13]
The dispersion according to any one of [1] to [12], wherein the ligand contains a halogen.
[14]
The dispersion according to any one of [1] to [13], wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.1 mol/dm 3 or more.
[15]
The dispersion according to any one of [1] to [14], wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.1 mol/dm 3 or more and 3 mol/dm 3 or less.
[16]
The dispersion according to any one of [1] to [15], wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.3 mol/dm 3 or more and 2 mol/dm 3 or less.
[17]
The dispersion according to any one of [1] to [16], wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.3 mol/dm 3 or more and 1.5 mol/dm 3 or less.
[18]
The dispersion according to any one of [1] to [17], wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.5 mol/dm 3 or more and 1 mol/dm 3 or less.
[19]
In the dispersion, the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.001 or more, the dispersion according to any one of [1] to [18].
[20]
In the dispersion, the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.001 or more and 5 or less, the dispersion according to any one of [1] to [19].
[21]
In the dispersion, the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.003 or more and 1.5 or less, the dispersion according to any one of [1] to [20].
[22]
In the dispersion, the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dot) is 0.01 or more and 1.1 or less, the dispersion according to any one of [1] to [21].
[23]
In the dispersion, the mass ratio of the organic compound having an amino group and a carboxyl group and the hydride thereof to the quantum dots (calculated without ligands) (total of the organic compound and its hydride / the quantum dots) is 0.03 or more and 0.8 or less.
[24]
In the dispersion liquid, the mass ratio of the quantum dots to the perovskite compound and/or its precursor [the quantum dots/(the perovskite compound and/or its precursor)] is 0.1 or more [1] to [23] The dispersion according to any one of [23].
[25]
[1 ] to [24].
[26]
[1 ] to [25].
[27]
In the dispersion, the mass ratio of the quantum dots to the perovskite compound and/or its precursor [the quantum dots/(the perovskite compound and/or its precursor)] is 0.3 or more and 0.7 or less. The dispersion liquid according to any one of [1] to [26].
[28]
The dispersion according to any one of [1] to [27], wherein the content or amount of the perovskite compound and/or its precursor in the dispersion is 5% by mass or more and 50% by mass or less.
[29]
The dispersion according to any one of [1] to [28], wherein the content or amount of the perovskite compound and/or its precursor in the dispersion is 10% by mass or more and 40% by mass or less.
[30]
The dispersion according to any one of [1] to [29], wherein the perovskite compound and/or its precursor content or amount in the dispersion is 15% by mass or more and 30% by mass or less.
[31]
The dispersion according to any one of [1] to [30], wherein the content or amount of the quantum dots in the dispersion is 1% by mass or more and 40% by mass or less.
[32]
The dispersion according to any one of [1] to [31], wherein the content or amount of the quantum dots in the dispersion is 3% by mass or more and 30% by mass or less.
[33]
The dispersion according to any one of [1] to [32], wherein the content or amount of the quantum dots in the dispersion is 5% by mass or more and 20% by mass or less.
[34]
[1] to [33], wherein the hydrochloride of the organic compound having an amino group and a carboxy group and/or the content or blending amount thereof in the dispersion liquid is 0.01% by mass or more and 20% by mass or less. Dispersion according to any one.
[35]
[1] to [34], wherein the hydrochloride of the organic compound having an amino group and a carboxy group and/or the content or blending amount thereof in the dispersion liquid is 0.03% by mass or more and 10% by mass or less. Dispersion according to any one.
[36]
In the dispersion, the hydrochloride of the organic compound having an amino group and a carboxyl group and/or its content or amount) is 0.1% by mass or more and 5% by mass or less, [1] to [35] The dispersion according to any one of .
[37]
The dispersion according to any one of [1] to [36], which is for forming a light absorption layer.
[38]
A light absorbing layer obtained from the dispersion according to any one of [1] to [37].
[39]
A light absorption layer containing a perovskite compound, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydrochloride thereof.
[40]
The light-absorbing layer according to [39], wherein the organic compound having an amino group and a carboxy group is one or more selected from aliphatic amino acids and aromatic amino acids.
[41]
The light-absorbing layer according to [39] or [40], wherein the hydrochloride is a hydrohalide.
[42]
The light absorption layer according to any one of [39] to [41], wherein the ligand is one or more selected from organic compounds and halogen-containing substances.
[43]
The light absorption layer according to any one of [39] to [42], wherein the content of the quantum dots in the light absorption layer is 5 vol% or more.
[44]
The light absorption layer according to any one of [39] to [43], wherein the content of the quantum dots in the light absorption layer is 5 vol% or more and 40 vol% or less.
[45]
The light absorption layer according to any one of [39] to [44], wherein the content of the quantum dots in the light absorption layer is 7.5 vol% or more and 30 vol% or less.
[46]
The light absorption layer according to any one of [39] to [45], wherein the content of the quantum dots in the light absorption layer is 10 vol% or more and 25 vol% or less.
[47]
The light absorption layer according to any one of [39] to [46], wherein the content of the quantum dots in the light absorption layer is 12 vol% or more and 25 vol% or less.
[48]
A photoelectric conversion device comprising the light absorption layer according to any one of [38] to [47].
[49]
A solar cell comprising the photoelectric conversion element according to [48].
[50]
mixing the perovskite compound and/or precursor thereof, the quantum dot having the ligand, and the organic compound having an amino group and a carboxyl group and/or a hydride thereof, [1] to [36] ] The method for producing a dispersion according to any one of the above.
　以下、本発明について、実施例に基づき具体的に説明する。また、評価・測定方法は以下のとおりである。なお、特に断らない限り、実施、測定は２５℃、常圧の環境で行った。なお、「常圧」とは１０１．３ｋＰａを示す。 The present invention will be specifically described below based on examples. In addition, the evaluation and measurement methods are as follows. In addition, unless otherwise specified, implementation and measurement were performed in an environment of 25° C. and normal pressure. In addition, "ordinary pressure" indicates 101.3 kPa.
＜吸収スペクトル＞
　光吸収層の吸収スペクトルは、正孔輸送剤を塗布する前の試料において、ＵＶ－Ｖｉｓ分光光度計（株式会社島津製作所製、ＳｏｌｉｄＳｐｅｃ－３７００）を用い、スキャンスピード中速、サンプルピッチ１ｎｍ、スリット幅２０、検出器ユニット積分球の条件で３００～１６００ｎｍの範囲を測定した。ＦＴＯ（Ｆｌｕｏｒｉｎｅ－ｄｏｐｅｄ ｔｉｎ ｏｘｉｄｅ）基板（旭硝子ファブリテック株式会社製、２５×２５×１．８ｍｍ）でバックグラウンド測定を行った。
　オレイン酸が配位したＰｂＳ量子ドット分散液の吸収スペクトルは、ＰｂＳ量子ドット固体０．１ｍｇ／ｍＬ以上１ｍｇ／ｍＬ以下の濃度の分散液において、１ｃｍ角石英セルを用いて、同様に測定した。 <Absorption spectrum>
The absorption spectrum of the light-absorbing layer was measured using a UV-Vis spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) in a sample before applying the hole transport agent, using a medium scan speed, a sample pitch of 1 nm, and a slit. A range of 300 to 1600 nm was measured under the conditions of a width of 20 and a detector unit integrating sphere. Background measurement was performed using an FTO (fluorine-doped tin oxide) substrate (25×25×1.8 mm, manufactured by Asahi Glass Fabricec Co., Ltd.).
The absorption spectrum of the oleic acid-coordinated PbS quantum dot dispersion was similarly measured using a 1 cm square quartz cell in a PbS quantum dot solid dispersion with a concentration of 0.1 mg/mL or more and 1 mg/mL or less.
＜Ｉ－Ｖ曲線＞
　キセノンランプ白色光を光源（ペクセル・テクノロジーズ社製、ＰＥＣ－Ｌ０１）とし、太陽光（ＡＭ１．５）相当の光強度（１００ｍＷ／ｃｍ２）にて、光照射面積０．０７０４ｃｍ２となるマスク下、Ｉ－Ｖ特性計測装置（ペクセル・テクノロジーズ社製、ＰＥＣＫ２４００－Ｎ）を用いて走査速度０．１Ｖ／ｓｅｃ（０．０１Ｖ ｓｔｅｐ）、電圧設定後待ち時間１００ｍｓｅｃ、測定積算時間１００ｍｓｅｃ、開始電圧－０．２Ｖ、終了電圧１．４Ｖの条件でセルのＩ－Ｖ曲線を測定した。なお、シリコンリファレンス（ＢＳ－５２０、０．５７１４ｍＡ）で光強度補正を行った。Ｉ－Ｖ曲線から変換効率（％）、短絡電流密度（ｍＡ／ｃｍ２）、開放電圧（Ｖ）、及びフィルファクター（ＦＦ）を求めた。 <IV curve>
Using white light from a xenon lamp as a light source (PEC-L01, manufactured by Peccell Technologies), and a light intensity (100 mW/cm 2 ) equivalent to sunlight (AM1.5), the light irradiation area is 0.0704 cm 2 under the mask. , Scanning speed 0.1 V / sec (0.01 V step) using an IV characteristic measuring device (PECK2400-N manufactured by Peccell Technologies), waiting time 100 msec after voltage setting, measurement integration time 100 msec, starting voltage - The IV curve of the cell was measured under the conditions of 0.2V and 1.4V end voltage. The light intensity was corrected with a silicon reference (BS-520, 0.5714 mA). Conversion efficiency (%), short-circuit current density (mA/cm 2 ), open-circuit voltage (V), and fill factor (FF) were obtained from the IV curve.
＜オレイン酸が配位したＰｂＳ量子ドットの合成＞
　酸化鉛（富士フイルム和光純薬株式会社製）４.５ｇ、オクタデセン（シグマ アルドリッチ ジャパン合同会社製）１００ｇ、オレイン酸（シグマ アルドリッチ ジャパン合同会社製）１３．５ｇを３００ｍＬ三口フラスコに入れ、反応系内を真空ポンプにより脱気し、窒素ガスを導入して大気圧に戻す操作を繰り返し３回行い、窒素置換した。その後、マントルにて混合液を８０℃に昇温し、２時間撹拌してＰｂ源溶液を調製した。更に１１０℃に昇温し、３０分間撹拌した。一方、１，１，１，３，３，３－ヘキサメチルジシラチアン（東京化成工業株式会社製）２．１ｍＬをオクタデセン３２ｇに溶解し、Ｓ源溶液を調製した。１１０℃、撹拌、窒素ガス雰囲気下、シリンジを用いてＳ源溶液をＰｂ源溶液に一気に注入し、オレイン酸が配位したＰｂＳ量子ドットを生成させた。注入後はすぐにマントルから３００ｍＬ三口フラスコをとりだし、事前に冷やした鉄粉に漬けて急冷却し、反応を停止させた。回収した反応液を二等分し、それぞれにヘキサン４０ｇ、アセトン２００ｇを加えて激しく振ることで洗浄を行った。その後、遠心分離（日立工機株式会社製、ＣＲ２１ＧIII、Ｒ１５Ａローター、６０００ｒｐｍ、５分）処理を施し、遠心分離後に上澄みを除去し、沈殿物を一つにまとめて回収した。引き続き、沈殿物にヘキサン７０ｇ、アセトン１６０ｇを加えて激しく振り、洗浄を行い、上記と同条件で遠心分離処理を施し、遠心分離後に上澄みを除去して沈殿物を回収した。前記の操作を２回実施後、得られた沈殿物にヘキサン７０ｇを加えて、上記と同条件で遠心分離処理を施し、上澄み液を回収した。回収した上澄み液にアセトン１６０ｇを加えて激しく振り、上記と同条件で遠心分離処理を施し、遠心分離後に上澄みを除去して沈殿物を回収した。回収した沈殿物を減圧乾燥して、オレイン酸が配位したＰｂＳ量子ドット固体を得た。
　オレイン酸が配位したＰｂＳ量子ドット固体中の各濃度は、Ｐｂ＝６６質量％、オレイン酸＝２２質量％であり、オレイン酸／Ｐｂモル比＝０．２５であった。Ｘ線回折結果より結晶子径２．７ｎｍ、吸収スペクトルより吸収端波長１０７０ｎｍ、吸収ピーク波長９７０ｎｍ（固形分濃度１ｍｇ／ｍＬヘキサン分散液のピーク吸光度０．５０１）であった。 <Synthesis of PbS quantum dots coordinated with oleic acid>
4.5 g of lead oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 100 g of octadecene (manufactured by Sigma-Aldrich Japan G.K.), and 13.5 g of oleic acid (manufactured by Sigma-Aldrich Japan G.K.) were placed in a 300 mL three-necked flask, and added to the reaction system. was degassed with a vacuum pump, nitrogen gas was introduced to return to atmospheric pressure, and the operation was repeated three times to replace with nitrogen. After that, the mixture was heated to 80° C. with a mantle and stirred for 2 hours to prepare a Pb source solution. Further, the temperature was raised to 110° C. and stirred for 30 minutes. On the other hand, 2.1 mL of 1,1,1,3,3,3-hexamethyldisilathiane (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 32 g of octadecene to prepare an S source solution. A syringe was used to inject the S source solution into the Pb source solution at once under stirring at 110° C. and in a nitrogen gas atmosphere, thereby forming PbS quantum dots coordinated with oleic acid. Immediately after the injection, the 300 mL three-necked flask was removed from the mantle and immersed in pre-chilled iron powder for rapid cooling to stop the reaction. The collected reaction liquid was divided into two equal parts, and 40 g of hexane and 200 g of acetone were added to each of the equal parts, followed by vigorous shaking for washing. Thereafter, centrifugation (CR21GIII, R15A rotor, manufactured by Hitachi Koki Co., Ltd., 6000 rpm, 5 minutes) was applied, and after centrifugation, the supernatant was removed and the precipitates were collectively recovered. Subsequently, 70 g of hexane and 160 g of acetone were added to the precipitate, and the mixture was vigorously shaken, washed, and centrifuged under the same conditions as above. After centrifugation, the supernatant was removed to collect the precipitate. After performing the above operation twice, 70 g of hexane was added to the resulting precipitate, and the mixture was centrifuged under the same conditions as above to collect the supernatant. 160 g of acetone was added to the collected supernatant, the mixture was vigorously shaken, and centrifuged under the same conditions as above. After centrifugation, the supernatant was removed to collect precipitates. The collected precipitate was dried under reduced pressure to obtain a PbS quantum dot solid with coordinated oleic acid.
The respective concentrations in the oleic acid-coordinated PbS quantum dot solid were Pb = 66 wt%, oleic acid = 22 wt%, and the oleic acid/Pb molar ratio = 0.25. The crystallite diameter was 2.7 nm from the X-ray diffraction results, and the absorption edge wavelength was 1070 nm and the absorption peak wavelength was 970 nm from the absorption spectrum (peak absorbance of solid content concentration 1 mg/mL hexane dispersion: 0.501).
＜ヨウ素が配位したＰｂＳ量子ドットの合成＞
　上記のオレイン酸が配位したＰｂＳ量子ドット固体０．２０ｇをトルエン（脱水、富士フイルム和光純薬株式会社製）２ｍＬに分散させ、黒色透明分散液を得た。一方、メチルアミンヨウ化水素酸塩（０．０５３ｇ、東京化成工業株式会社製）をＤＭＦ（脱水、富士フイルム和光純薬株式会社製）０．５ｍＬとトルエン（脱水、富士フイルム和光純薬株式会社製）１ｍＬに溶解させてメチルアミンヨウ化水素酸塩溶液を得た（メチルアミンヨウ化水素酸塩／オレイン酸モル比＝２）。室温（２５℃）、窒素雰囲気下（グローブボックス内）、無撹拌下、上記メチルアミンヨウ化水素酸塩溶液をＰｂＳ量子ドット分散液に１滴／１０秒の滴下速度（滴下時間１１分）で滴下後、１８時間静置した。更にメタノール５ｍＬを添加、混合後、フィルター（孔径０．２μｍ、材質ＰＴＦＥ）ろ過、乾燥させることにより、ヨウ素が配位したＰｂＳ量子ドット固体を得た。 <Synthesis of PbS quantum dots coordinated with iodine>
0.20 g of the oleic acid-coordinated PbS quantum dot solid was dispersed in 2 mL of toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) to obtain a black transparent dispersion. On the other hand, methylamine hydroiodide (0.053 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 0.5 mL of DMF (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). product) to obtain a methylamine hydroiodide solution (methylamine hydroiodide/oleic acid molar ratio=2). At room temperature (25° C.) under a nitrogen atmosphere (in a glove box) without stirring, the methylamine hydroiodide solution was added to the PbS quantum dot dispersion at a drop rate of 1 drop/10 seconds (dropping time: 11 minutes). After dropping, it was allowed to stand still for 18 hours. Further, 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 μm, material: PTFE), and dried to obtain a PbS quantum dot solid with iodine coordinated.
＜４－アミノブタン酸臭化水素酸塩の合成＞
　４－アミノブタン酸（東京化成株式会社製）１１．２ｇ、臭化水素酸（４７％、東京化成株式会社製）１９．７ｇ、メタノール３７０ｇを５００ｍＬのフラスコに入れ、アミノ基を中和するため、３時間熟成した。その後、エバポレーターにてメタノール、水分を除去して濃縮した。濃縮物を１晩凍結乾燥することで、４－アミノブタン酸臭化水素酸塩を調製した。 <Synthesis of 4-aminobutanoic acid hydrobromide>
11.2 g of 4-aminobutanoic acid (manufactured by Tokyo Kasei Co., Ltd.), 19.7 g of hydrobromic acid (47%, manufactured by Tokyo Kasei Co., Ltd.), and 370 g of methanol were placed in a 500 mL flask to neutralize the amino group. Aged for 3 hours. After that, methanol and water were removed by an evaporator, and the mixture was concentrated. 4-Aminobutanoic acid hydrobromide was prepared by lyophilizing the concentrate overnight.
＜４－アミノブタン酸が配位したＰｂＳ量子ドットの合成＞
　上記のオレイン酸が配位したＰｂＳ量子ドット固体０．２０ｇをトルエン（脱水、富士フイルム和光純薬株式会社製）２ｍＬに分散させ、黒色透明分散液を得た。一方、上記の４－アミノブタン酸臭化水素酸塩０．０６１ｇをＤＭＦ（脱水、富士フイルム和光純薬株式会社製）０．５ｍＬとトルエン（脱水、富士フイルム和光純薬株式会社製）１ｍＬに溶解させてアミノ酸塩溶液を得た（４－アミノブタン酸臭化水素酸塩／オレイン酸モル比＝２）。室温（２５℃）、窒素雰囲気下（グローブボックス内）、無撹拌下、上記アミノ酸塩溶液をＰｂＳ量子ドット分散液に１滴／１０秒の滴下速度で滴下後、１８時間静置した。更にメタノール５ｍＬを添加、混合後、フィルター（孔径０．２μｍ、材質ＰＴＦＥ）ろ過、乾燥させることにより、４－アミノブタン酸が配位したＰｂＳ量子ドット固体を得た。 <Synthesis of PbS quantum dots coordinated with 4-aminobutanoic acid>
0.20 g of the oleic acid-coordinated PbS quantum dot solid was dispersed in 2 mL of toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) to obtain a black transparent dispersion. On the other hand, 0.061 g of the above 4-aminobutanoic acid hydrobromide was dissolved in 0.5 mL of DMF (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and 1 mL of toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). to obtain an amino acid salt solution (4-aminobutanoic acid hydrobromide/oleic acid molar ratio=2). At room temperature (25° C.) under a nitrogen atmosphere (inside a glove box) without stirring, the above amino acid salt solution was added dropwise to the PbS quantum dot dispersion at a dropping rate of 1 drop/10 seconds, and then allowed to stand for 18 hours. Further, 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 μm, material: PTFE), and dried to obtain a PbS quantum dot solid with 4-aminobutanoic acid coordinated.
＜７－アミノヘプタン酸臭化水素酸塩の合成＞
　７－アミノヘプタン酸（東京化成株式会社製）１５．４ｇ、臭化水素酸（４７％、東京化成株式会社製）１８．６ｇ、メタノール３６６ｇを５００ｍＬのフラスコに入れ、アミノ基を中和するため、３時間熟成した。その後、エバポレーターにてメタノール、水分を除去して濃縮した。濃縮物を１晩凍結乾燥することで、７－アミノヘプタン酸臭化水素酸塩を調製した。 <Synthesis of 7-aminoheptanoic acid hydrobromide>
15.4 g of 7-aminoheptanoic acid (manufactured by Tokyo Kasei Co., Ltd.), 18.6 g of hydrobromic acid (47%, manufactured by Tokyo Kasei Co., Ltd.), and 366 g of methanol were placed in a 500 mL flask to neutralize the amino group. , aged for 3 hours. After that, methanol and water were removed by an evaporator, and the mixture was concentrated. 7-Aminoheptanoic acid hydrobromide was prepared by lyophilizing the concentrate overnight.
＜７－アミノヘプタン酸が配位したＰｂＳ量子ドットの合成＞
　上記のオレイン酸が配位したＰｂＳ量子ドット固体０．２０ｇをトルエン（脱水、富士フイルム和光純薬株式会社製）２ｍＬに分散させ、黒色透明分散液を得た。一方、上記の７－アミノヘプタン酸臭化水素酸塩０．０７５ｇをＤＭＦ（脱水、富士フイルム和光純薬株式会社製）０．５ｍＬとトルエン（脱水、富士フイルム和光純薬株式会社製）１ｍＬに溶解させてアミノ酸塩溶液を得た（７－アミノヘプタン酸臭化水素酸塩／オレイン酸モル比＝２）。室温（２５℃）、窒素雰囲気下（グローブボックス内）、無撹拌下、上記アミノ酸塩溶液をＰｂＳ量子ドット分散液に１滴／１０秒の滴下速度で滴下後、１８時間静置した。更にメタノール５ｍＬを添加、混合後、フィルター（孔径０．２μｍ、材質ＰＴＦＥ）ろ過、乾燥させることにより、７－アミノヘプタン酸が配位したＰｂＳ量子ドット固体を得た。 <Synthesis of PbS quantum dots coordinated with 7-aminoheptanoic acid>
0.20 g of the oleic acid-coordinated PbS quantum dot solid was dispersed in 2 mL of toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) to obtain a black transparent dispersion. On the other hand, 0.075 g of the above 7-aminoheptanoic acid hydrobromide was added to 0.5 mL of DMF (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and 1 mL of toluene (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). Dissolution gave an amino acid salt solution (7-aminoheptanoic acid hydrobromide/oleic acid molar ratio=2). At room temperature (25° C.) under a nitrogen atmosphere (inside a glove box) without stirring, the above amino acid salt solution was added dropwise to the PbS quantum dot dispersion at a dropping rate of 1 drop/10 seconds, and then allowed to stand for 18 hours. Further, 5 mL of methanol was added, mixed, filtered through a filter (pore size: 0.2 μm, material: PTFE), and dried to obtain a PbS quantum dot solid with 7-aminoheptanoic acid coordinated.
実施例１
　次の（１）～（７）の工程を順に行い、セルを作製した。
（１）ＦＴＯ基板のエッチング、洗浄
　２５ｍｍ角のフッ素ドープ酸化スズ（ＦＴＯ）付ガラス基板（旭硝子ファブリテック株式会社製、２５×２５×１．８ｍｍ、以下、ＦＴＯ基板という）の一部をＺｎ粉末と２ｍｏｌ／Ｌ塩酸水溶液でエッチングした。１質量％中性洗剤、アセトン、２－プロパノール（ＩＰＡ）、脱イオン水で、この順に各１０分間超音波洗浄を行った。 Example 1
A cell was fabricated by performing the following steps (1) to (7) in order.
(1) Etching and cleaning of FTO substrate Part of a 25 mm square glass substrate with fluorine-doped tin oxide (FTO) (manufactured by Asahi Glass Fabric Tech Co., Ltd., 25 x 25 x 1.8 mm, hereinafter referred to as FTO substrate) was coated with Zn powder. and a 2 mol/L hydrochloric acid aqueous solution. Ultrasonic cleaning was performed for 10 minutes each using 1 mass % neutral detergent, acetone, 2-propanol (IPA), and deionized water in this order.
（２）オゾン洗浄
　緻密ＴｉＯ２層形成工程の直前にＦＴＯ基板のオゾン洗浄を行った。ＦＴＯ面を上にして、基板をオゾン発生装置（メイワフォーシス株式会社製、オゾンクリーナー、ＰＣ－４５０ＵＶ）に入れ、３０分間ＵＶ照射した。 (2) Ozone Cleaning The FTO substrate was cleaned with ozone immediately before the dense TiO 2 layer forming process. With the FTO surface facing up, the substrate was placed in an ozone generator (Ozone Cleaner PC-450UV manufactured by Meiwa Forsys Co., Ltd.) and irradiated with UV for 30 minutes.
（３）緻密ＴｉＯ２層（ブロッキング層）の形成
　エタノール（脱水、富士フイルム和光純薬株式会社製）１２３．２４ｇにビス（２，４－ペンタンジオナト）ビス（２－プロパノラト）チタニウム（ＩＶ）（７５％ＩＰＡ溶液、東京化成工業株式会社製）４．０４ｇを溶解させ、スプレー溶液を調製した。ホットプレート（３００℃）上のＦＴＯ基板に約３０ｃｍの高さから０．３ＭＰａでスプレーした。２０ｃｍ×８列を２回繰り返して約７ｇスプレー後、３００℃で３分間乾燥した。この操作を更に２回行うことにより合計約２１ｇの溶液をスプレーし、緻密ＴｉＯ２（ｃＴｉＯ２）層を形成した。 (3) Formation of dense TiO 2 layer (blocking layer) Bis(2,4-pentanedionato)bis(2-propanolate)titanium (IV) was added to 123.24 g of ethanol (dehydrated, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). (75% IPA solution, Tokyo Chemical Industry Co., Ltd.) 4.04 g was dissolved to prepare a spray solution. The FTO substrate on the hot plate (300° C.) was sprayed at 0.3 MPa from a height of about 30 cm. After spraying about 7 g of 20 cm x 8 rows twice, it was dried at 300°C for 3 minutes. This operation was repeated two more times to spray a total of about 21 g of solution to form a dense TiO 2 (cTiO 2 ) layer.
（４）メソポーラスＴｉＯ２層（多孔質層）の形成
　アナターゼ型ＴｉＯ２ペースト（ＰＳＴ－１８ＮＲ、日揮触媒化成株式会社製）０．４ｇにエタノール（脱水、富士フイルム和光純薬株式会社製）３．２ｇを加え、１時間超音波分散を行い、ＴｉＯ２コート液を調製した。ドライルーム内において、上記のｃＴｉＯ２層上にスピンコーター（ミカサ株式会社製、ＭＳ－１００）を用いてＴｉＯ２コート液をスピンコートした（スロープ３ｓｅｃ、４０００ｒｐｍ×３０ｓｅｃ）。１１０℃のホットプレート上で３０分間乾燥後、５００℃で３０分焼成（昇温時間６０分）することにより、メソポーラスＴｉＯ２（ｍＴｉＯ２）層を形成した。 (4) Formation of mesoporous TiO 2 layer (porous layer) 0.4 g of anatase-type TiO 2 paste (PST-18NR, manufactured by Nikki Shokubai Kasei Co., Ltd.) was added with ethanol (dehydrated, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)3. 2 g was added and ultrasonically dispersed for 1 hour to prepare a TiO 2 coating liquid. In a dry room, a TiO 2 coating solution was spin-coated on the cTiO 2 layer using a spin coater (manufactured by Mikasa Corporation, MS-100) (slope 3 sec, 4000 rpm×30 sec). A mesoporous TiO 2 (mTiO 2 ) layer was formed by drying on a hot plate at 110° C. for 30 minutes and baking at 500° C. for 30 minutes (heating time: 60 minutes).
（５）光吸収層の形成
　臭化鉛（ＰｂＢｒ２、ペロブスカイト前駆体用、東京化成工業株式会社製）０．２９３６ｇ、メチルアミン臭化水素酸塩（ＣＨ３ＮＨ３Ｂｒ、東京化成工業株式会社製）０．０８９６ｇ、４－アミノブタン酸臭化水素酸塩（上記合成）０．００５４ｇ、ＤＭＦ（脱水、富士フイルム和光純薬株式会社製）０．９ｍＬとＤＭＳＯ（脱水、富士フイルム和光純薬株式会社製）０．１ｍＬを混合、室温で撹拌し、４－アミノブタン酸臭化水素酸塩を含む０．８ｍｏｌ／Ｌペロブスカイト（ＣＨ３ＮＨ３ＰｂＢｒ３）原料のＤＭＦ/ＤＭＳＯ溶液（無色透明）を調製した。更に、このＤＭＦ/ＤＭＳＯ溶液に上記のヨウ素が配位したＰｂＳ量子ドット固体０．２０６ｇを加え、５分間、試験管を手で振ることでヨウ素が配位したＰｂＳ量子ドットの固形分が消失して、分散されていることを目視で確認し、光吸収層形成用分散液を得た。
　光吸収層の形成は、２５℃のグローブボックス内にて行った。上記のｍＴｉＯ２層上にスピンコーター（ミカサ株式会社製、ＭＳ－１００）を用いて前記光吸収層形成用分散液をスピンコートした（スロープ３ｓｅｃ、４０００ｒｐｍ×３０ｓｅｃ）。なお、スピン開始７秒後に貧溶媒であるクロロベンゼン（シグマアルドリッチ社製）１ｍＬをスピン中心部に一気に滴下した。スピンコート後すぐに１００℃ホットプレート上で１０分間乾燥させ、光吸収層を形成した。この光吸収層にはペロブスカイト化合物ＣＨ３ＮＨ３ＰｂＢｒ３、ＰｂＳ量子ドット、配位子、及び４－アミノブタン酸臭化水素酸塩が含まれる。ペロブスカイト化合物が生成していることはＸ線回折パターン、吸収スペクトルにより、また、量子ドットが存在していることは吸収スペクトルから確認した。 (5) Formation of light absorption layer 0.2936 g of lead bromide ( PbBr2 , for perovskite precursor, manufactured by Tokyo Chemical Industry Co., Ltd.), methylamine hydrobromide ( CH3NH3Br , Tokyo Chemical Industry Co., Ltd.) ) 0.0896 g, 4-aminobutanoic acid hydrobromide (synthesized above) 0.0054 g, DMF (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) 0.9 mL and DMSO (dehydrated, FUJIFILM Wako Pure Chemical Industries, Ltd.) Company) 0.1 mL was mixed and stirred at room temperature . prepared. Furthermore, 0.206 g of the above-described iodine-coordinated PbS quantum dot solid was added to the DMF/DMSO solution, and the test tube was shaken by hand for 5 minutes to eliminate the solid content of the iodine-coordinated PbS quantum dots. It was visually confirmed that the particles were dispersed, and a dispersion liquid for forming a light absorption layer was obtained.
Formation of the light absorbing layer was performed in a glove box at 25°C. Using a spin coater (MS-100, manufactured by Mikasa Co., Ltd.), the dispersion for forming a light absorption layer was spin-coated on the mTiO 2 layer (slope 3 sec, 4000 rpm×30 sec). Seven seconds after the start of the spin, 1 mL of chlorobenzene (manufactured by Sigma-Aldrich), which is a poor solvent, was dropped at once at the center of the spin. Immediately after spin coating, it was dried on a 100° C. hot plate for 10 minutes to form a light absorbing layer. The light-absorbing layer contains the perovskite compound CH 3 NH 3 PbBr 3 , PbS quantum dots, ligands, and 4-aminobutanoic acid hydrobromide. It was confirmed from the X-ray diffraction pattern and absorption spectrum that a perovskite compound was produced, and the presence of quantum dots was confirmed from the absorption spectrum.
（６）正孔輸送層の形成
　正孔輸送層の形成は、２５℃のグローブボックス内にて行った。ビス（トリフルオロメタンスルホニル）イミドリチウム（ＬｉＴＦＳＩ、富士フイルム和光純薬株式会社製）９．１ｍｇ、［トリス（２－（１Ｈ－ピラゾール－１－イル）－４－ｔｅｒｔ－ブチルピリジン）コバルト（III）トリス（ビス（トリフルオロメチルスルホニル）イミド）］（Ｃｏ（４－ｔＢｕｔｙｌｐｙｒｉｄｙｌ－２－１Ｈ－ｐｙｒａｚｏｌｅ）３．３ＴＦＳＩ、富士フイルム和光純薬株式会社製）８．７ｍｇ、２，２’，７，７’－テトラキス［Ｎ，Ｎ－ジ－ｐ－メトキシフェニルアミノ］－９，９’－スピロビフルオレン（Ｓｐｉｒｏ－ＯＭｅＴＡＤ、富士フイルム和光純薬株式会社製）７２．３ｍｇ、クロロベンゼン（シグマアルドリッチ社製）１ｍＬ、４－ｔｅｒｔ－ブチルピリジン（ＴＢＰ、シグマアルドリッチ製）２８．８μＬを混合し、室温撹拌して正孔輸送剤（ＨＴＭ）溶液（黒紫色透明）を調製した。使用直前に、ＨＴＭ溶液を孔径０．４５μｍのＰＴＦＥフィルターでろ過した。上記の光吸収層上にスピンコーター（ミカサ株式会社製、ＭＳ－１００）を用いてＨＴＭ溶液をスピンコートした（スロープ３ｓｅｃ、４０００ｒｐｍ×３０ｓｅｃ）。スピンコート後すぐに７０℃ホットプレート上で１０分間乾燥した。乾燥後、γ－ブチロラクトン（富士フイルム和光純薬株式会社製）を浸み込ませた綿棒でＦＴＯとのコンタクト部分および基板裏面全体を拭き取り、正孔輸送層を形成した。 (6) Formation of hole transport layer Formation of the hole transport layer was performed in a glove box at 25°C. Bis (trifluoromethanesulfonyl) imide lithium (LiTFSI, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 9.1 mg, [tris (2-(1H-pyrazol-1-yl)-4-tert-butylpyridine) cobalt (III) Tris (bis (trifluoromethylsulfonyl) imide)] (Co (4-tButylpyridyl-2-1H-pyrazole) 3.3 TFSI, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 8.7 mg, 2,2',7,7 '-tetrakis [N,N-di-p-methoxyphenylamino]-9,9'-spirobifluorene (Spiro-OMeTAD, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 72.3 mg, chlorobenzene (manufactured by Sigma-Aldrich) 1 mL and 28.8 μL of 4-tert-butylpyridine (TBP, manufactured by Sigma-Aldrich) were mixed and stirred at room temperature to prepare a hole transport agent (HTM) solution (black purple transparent). Immediately before use, the HTM solution was filtered through a 0.45 μm pore size PTFE filter. The HTM solution was spin-coated on the light absorption layer using a spin coater (manufactured by Mikasa Corporation, MS-100) (slope 3 sec, 4000 rpm×30 sec). Immediately after spin coating, it was dried on a 70° C. hot plate for 10 minutes. After drying, a cotton swab impregnated with γ-butyrolactone (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used to wipe off the contact portion with FTO and the entire back surface of the substrate to form a hole transport layer.
（７）金電極の蒸着
　真空蒸着装置（アルバック機工株式会社製、ＶＴＲ－０６０Ｍ/ＥＲＨ）を用い、真空下（４～５×１０－３Ｐａ）、上記の正孔輸送層上に金を１００ｎｍ蒸着（蒸着速度１～２Å／ｓｅｃ）して、金電極を形成した。 (7) Deposition of gold electrode Using a vacuum deposition device (VTR-060M/ERH, manufactured by ULVAC KIKO Co., Ltd.), under vacuum (4 to 5 × 10 -3 Pa), 100 nm of gold is deposited on the hole transport layer. A gold electrode was formed by vapor deposition (deposition rate 1-2 Å/sec).
（８）作成した太陽電池の発電性能
　Ｉ－Ｖ曲線から求めた変換効率は０．０５（％）、短絡電流密度は０．１８（ｍＡ／ｃｍ２）、開放電圧は０．５０（Ｖ）、及びフィルファクター（ＦＦ）は０．５０であった。 (8) Power generation performance of the produced solar cell The conversion efficiency obtained from the IV curve was 0.05 (%), the short-circuit current density was 0.18 (mA/cm 2 ), and the open-circuit voltage was 0.50 (V). , and the fill factor (FF) was 0.50.
実施例２
　実施例１において、４－アミノブタン酸臭化水素酸塩の量を０．０５４２ｇとした以外は、実施例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。作成した太陽電池の発電性能について、Ｉ－Ｖ曲線から求めた変換効率は０．０８（％）、短絡電流密度は０．１９（ｍＡ／ｃｍ２）、開放電圧は０．８５（Ｖ）、及びフィルファクター（ＦＦ）は０．４８であった。 Example 2
A dispersion for forming a light absorption layer was prepared in the same manner as in Example 1, except that the amount of 4-aminobutanoic acid hydrobromide was changed to 0.0542 g, and a light absorption layer was formed. , a cell was fabricated. Regarding the power generation performance of the produced solar cell, the conversion efficiency obtained from the IV curve was 0.08 (%), the short-circuit current density was 0.19 (mA/cm 2 ), the open-circuit voltage was 0.85 (V), and fill factor (FF) was 0.48.
実施例３
　実施例１において、臭化鉛の量を０．１８３ｇ、メチルアミン臭化水素酸塩の量を０．０５６ｇ、４－アミノブタン酸臭化水素酸塩の量を０．０００２１ｇ、ヨウ素が配位したＰｂＳ量子ドット固体の量を０．０８１ｇとした以外は、実施例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。 Example 3
In Example 1, the amount of lead bromide was 0.183 g, the amount of methylamine hydrobromide was 0.056 g, the amount of 4-aminobutanoic acid hydrobromide was 0.00021 g, and iodine was coordinated. A dispersion liquid for forming a light absorption layer was prepared in the same manner as in Example 1, except that the amount of the PbS quantum dot solid was changed to 0.081 g, a light absorption layer was formed, and a cell was produced.
実施例４
　実施例３において、４－アミノブタン酸臭化水素酸塩の量を０．００２１ｇとした以外は、実施例３と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。 Example 4
In Example 3, a light absorption layer forming dispersion was prepared in the same manner as in Example 3, except that the amount of 4-aminobutanoic acid hydrobromide was changed to 0.0021 g, and a light absorption layer was formed. , a cell was fabricated.
実施例５
　実施例１において、４－アミノブタン酸臭化水素酸塩の代わりに７―アミノヘプタン酸臭化水素酸塩（０．００６７ｇ）を用いた以外は、実施例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。作成した太陽電池の発電性能について、Ｉ－Ｖ曲線から求めた変換効率は０．０６（％）、短絡電流密度は０．２２（ｍＡ／ｃｍ２）、開放電圧は０．４９（Ｖ）、及びフィルファクター（ＦＦ）は０．５７であった。 Example 5
A light absorbing layer was formed in the same manner as in Example 1, except that 7-aminoheptanoic acid hydrobromide (0.0067 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared, a light absorption layer was formed, and a cell was produced. Regarding the power generation performance of the produced solar cell, the conversion efficiency obtained from the IV curve was 0.06 (%), the short-circuit current density was 0.22 (mA/cm 2 ), the open-circuit voltage was 0.49 (V), and fill factor (FF) was 0.57.
実施例６
　実施例１において、ヨウ素が配位したＰｂＳ量子ドット固体の代わりにオレイン酸が配位したＰｂＳ量子ドット固体を用い、仕込み量を、オレイン酸が配位したＰｂＳ量子ドット固体を０．０８１ｇ、４－アミノブタン酸臭化水素酸塩を０．０５４２ｇとし、５分間、試験管を手で振った後、２５分間超音波分散し、オレイン酸が配位したＰｂＳ量子ドットの固形分が消失して、分散されていることを目視で確認した以外は、実施例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。作成した太陽電池の発電性能について、Ｉ－Ｖ曲線から求めた変換効率は０．２１５（％）、短絡電流密度は０．６２（ｍＡ／ｃｍ２）、開放電圧は０．５９（Ｖ）、及びフィルファクター（ＦＦ）は０．５８であった。 Example 6
In Example 1, oleic acid-coordinated PbS quantum dot solids were used instead of iodine-coordinated PbS quantum dot solids, and the charged amount was 0.081 g of oleic acid-coordinated PbS quantum dot solids. - 0.0542 g of aminobutanoic acid hydrobromide, shake the test tube by hand for 5 minutes, then ultrasonically disperse for 25 minutes, the solid content of the PbS quantum dots coordinated with oleic acid disappears, A dispersion liquid for forming a light absorption layer was prepared in the same manner as in Example 1 except that the dispersion was visually confirmed, a light absorption layer was formed, and a cell was produced. Regarding the power generation performance of the produced solar cell, the conversion efficiency obtained from the IV curve was 0.215 (%), the short-circuit current density was 0.62 (mA/cm 2 ), the open-circuit voltage was 0.59 (V), and fill factor (FF) was 0.58.
実施例７
　実施例１において、４－アミノブタン酸臭化水素酸塩の代わりに４－アミノフェニル酢酸（０．００１７ｇ）を用いた以外は、実施例１と同様の方法で光吸収層形成用分散液を調製した。 Example 7
A dispersion for forming a light absorbing layer was prepared in the same manner as in Example 1, except that 4-aminophenylacetic acid (0.0017 g) was used instead of 4-aminobutanoic acid hydrobromide. bottom.
実施例８
　実施例１において、４－アミノブタン酸臭化水素酸塩の代わりに４－アミノフェニル酢酸臭化水素酸塩（０．００２６ｇ）を用いた以外は、実施例１と同様の方法で光吸収層形成用分散液を調製した。 Example 8
A light absorption layer was formed in the same manner as in Example 1, except that 4-aminophenylacetic acid hydrobromide (0.0026 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared for
実施例９
　実施例１において、４－アミノブタン酸臭化水素酸塩の代わりに４－アミノ安息香酸（０．００１６ｇ）を用いた以外は、実施例１と同様の方法で光吸収層形成用分散液を調製した。 Example 9
A dispersion for forming a light absorbing layer was prepared in the same manner as in Example 1, except that 4-aminobenzoic acid (0.0016 g) was used instead of 4-aminobutanoic acid hydrobromide. bottom.
実施例１０
　実施例１において、４－アミノブタン酸臭化水素酸塩の代わりに４－アミノ安息香酸臭化水素酸塩（０．００２５ｇ）を用いた以外は、実施例１と同様の方法で光吸収層形成用分散液を調製した。 Example 10
A light absorbing layer was formed in the same manner as in Example 1, except that 4-aminobenzoic acid hydrobromide (0.0025 g) was used instead of 4-aminobutanoic acid hydrobromide. A dispersion was prepared for
比較例１
　臭化鉛（ＰｂＢｒ２、ペロブスカイト前駆体用、東京化成工業株式会社製）０．１１０ｇ、メチルアミン臭化水素酸塩（ＣＨ３ＮＨ３Ｂｒ、東京化成工業株式会社製）０．０３４ｇ、ＤＭＦ（脱水、富士フイルム和光純薬株式会社製）０．９ｍＬとＤＭＳＯ（脱水、富士フイルム和光純薬株式会社製）０．１ｍＬを混合、室温で撹拌し、０．３ｍｏｌ／Ｌペロブスカイト（ＣＨ３ＮＨ３ＰｂＢｒ３）原料のＤＭＦ/ＤＭＳＯ溶液（無色透明）を調製した。更に、このＤＭＦ/ＤＭＳＯ溶液に上記のヨウ素が配位したＰｂＳ量子ドット固体０．０１４ｇを加え、５分間、試験管を手で振ることでヨウ素が配位したＰｂＳ量子ドットの固形分が消失することを目視で確認し、光吸収層形成用分散液を得た。当該光吸収層形成用分散液を用いた以外は、実施例１と同様の方法で光吸収層を形成し、セルを作製した。 Comparative example 1
Lead bromide (PbBr 2 , for perovskite precursor, manufactured by Tokyo Chemical Industry Co., Ltd.) 0.110 g, methylamine hydrobromide (CH 3 NH 3 Br, manufactured by Tokyo Chemical Industry Co., Ltd.) 0.034 g, DMF ( 0.9 mL of dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and 0.1 mL of DMSO (dehydrated, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) were mixed, stirred at room temperature, and 0.3 mol/L perovskite (CH 3 NH 3 A DMF/DMSO solution (colorless and transparent) of PbBr 3 ) raw material was prepared. Furthermore, 0.014 g of the above iodine-coordinated PbS quantum dot solid is added to this DMF/DMSO solution, and the test tube is shaken by hand for 5 minutes to eliminate the solid content of the iodine-coordinated PbS quantum dots. This was visually confirmed, and a dispersion liquid for forming a light absorbing layer was obtained. A light absorbing layer was formed in the same manner as in Example 1 except that the dispersion for forming a light absorbing layer was used, and a cell was produced.
比較例２
　比較例１において、ヨウ素が配位したＰｂＳ量子ドット固体の代わりに４－アミノブタン酸が配位したＰｂＳ量子ドット固体（０．０４４ｇ）を用いた以外は、比較例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。 Comparative example 2
Light absorption was performed in the same manner as in Comparative Example 1, except that in Comparative Example 1, a 4-aminobutanoic acid-coordinated PbS quantum dot solid (0.044 g) was used instead of the iodine-coordinated PbS quantum dot solid. A layer forming dispersion was prepared, a light absorption layer was formed, and a cell was produced.
比較例３
　比較例１において、ヨウ素が配位したＰｂＳ量子ドット固体の代わりに７－アミノヘプタン酸が配位したＰｂＳ量子ドット固体（０．００４４ｇ）を用いた以外は、比較例１と同様の方法で光吸収層形成用分散液を調製し、光吸収層を形成し、セルを作製した。 Comparative example 3
In Comparative Example 1, light was emitted in the same manner as in Comparative Example 1, except that 7-aminoheptanoic acid-coordinated PbS quantum dot solid (0.0044 g) was used instead of the iodine-coordinated PbS quantum dot solid. A dispersion liquid for forming an absorption layer was prepared, a light absorption layer was formed, and a cell was produced.
＜分散液の初期分散性の評価＞
　光吸収層形成用分散液の初期分散性は目視評価にて行った。６ｍｌの茶色のバイアル管に１ｍｌの光吸収層形成用分散液を入れて、窒素を充填し、栓で密閉した。バイアル管を上下逆にすることで、バイアル管の下部に沈殿があるかどうかを目視で確認した。 <Evaluation of initial dispersibility of dispersion liquid>
The initial dispersibility of the dispersion liquid for forming the light absorbing layer was visually evaluated. A 6-ml brown vial tube was charged with 1 ml of the dispersion liquid for forming a light-absorbing layer, filled with nitrogen, and sealed with a stopper. By turning the vial tube upside down, it was visually confirmed whether there was any sediment at the bottom of the vial tube.
＜分散液の経日分散安定性の評価＞
　前記バイアル管を２０℃、暗所で保管した。光吸収層形成用分散液の経日分散安定性の評価は、初期分散性と同様に目視評価にて行った。
　分散液から光吸収層を得る観点から、分散液は、好ましくは５日以上、より好ましくは１０日以上安定であることが好ましい。
　尚、実施例６については、１０日間沈殿なしであり、更に長期の分散液の経日分散安定性を評価したところ、９０日間沈殿なしで安定であることが確認された。また、実施例７は、１３日まで安定であったのに対して、実施例８は１５日以上安定であった。 <Evaluation of long-term dispersion stability of dispersion liquid>
The vials were stored at 20°C in the dark. Evaluation of the aging dispersion stability of the light-absorbing layer-forming dispersion liquid was carried out by visual evaluation in the same manner as the initial dispersibility.
From the viewpoint of obtaining a light absorbing layer from the dispersion, the dispersion is preferably stable for 5 days or more, more preferably 10 days or more.
In Example 6, no sedimentation occurred for 10 days, and when the long-term dispersion stability of the dispersion was evaluated, it was confirmed to be stable without sedimentation for 90 days. Also, Example 7 was stable up to 13 days, while Example 8 was stable for 15 days or more.
＜遠心分離による分散液の分散安定性の評価＞
　前記経日分散安定性の評価にて１日後の分散安定性を確認した光吸収層形成用分散液に、遠心分離処理（６０００ｒｐｍ、１０分間）を施した。その後、取り出したバイアル管を傾け、沈殿物の有無を確認した。遠心分離による光吸収層形成用分散液の分散安定性の評価は、室温（２０℃）における２週間経日分散安定性の評価に該当すると考えられる。 <Evaluation of dispersion stability of dispersion by centrifugation>
A centrifugal separation treatment (6000 rpm, 10 minutes) was applied to the dispersion liquid for forming a light absorbing layer whose dispersion stability was confirmed after one day in the evaluation of the dispersion stability over time. After that, the taken-out vial tube was tilted and the presence or absence of precipitate was confirmed. Evaluation of the dispersion stability of the light-absorbing layer-forming dispersion by centrifugation is considered to correspond to evaluation of the dispersion stability over two weeks at room temperature (20° C.).
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明の分散液は、光吸収層形成用分散液として好適に使用することができる。本発明の光吸収層及び光電変換素子は、次世代太陽電池の構成部材として好適に使用することができる。 The dispersion of the present invention can be suitably used as a dispersion for forming a light absorption layer. The light absorbing layer and photoelectric conversion element of the present invention can be suitably used as constituent members of next-generation solar cells.
１：光電変換素子
２：透明基板
３：透明導電層
４：ブロッキング層
５：多孔質層
６：光吸収層
７：正孔輸送層
８：電極（正極）
９：電極（負極）
１０：光
  1: photoelectric conversion element 2: transparent substrate 3: transparent conductive layer 4: blocking layer 5: porous layer 6: light absorption layer 7: hole transport layer 8: electrode (positive electrode)
9: Electrode (negative electrode)
10: light

Claims (19)

  1. 　ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する分散液。 A dispersion liquid containing a perovskite compound and/or its precursor, a quantum dot having a ligand, and an organic compound having an amino group and a carboxy group and/or a hydride thereof.
  2. 　前記アミノ基及びカルボキシ基を有する有機化合物は、脂肪族アミノ酸及び芳香族アミノ酸から選ばれる１種以上である請求項１に記載の分散液。 The dispersion according to claim 1, wherein the organic compound having an amino group and a carboxy group is one or more selected from aliphatic amino acids and aromatic amino acids.
  3. 　前記アミノ基及びカルボキシ基を有する有機化合物の炭素数が、２以上１８以下である、請求項１又は２に記載の分散液。 The dispersion according to claim 1 or 2, wherein the organic compound having an amino group and a carboxy group has 2 or more and 18 or less carbon atoms.
  4. 　前記アミノ基及びカルボキシ基を有する有機化合物が、アミノプロパン酸、アミノブタン酸、アミノペンタン酸、アミノヘキサン酸、アミノヘプタン酸、アミノフェニル酢酸、及びアミノ安息香酸から選ばれる１種以上である、請求項１～３のいずれかに記載の分散液。 The organic compound having an amino group and a carboxy group is one or more selected from aminopropanoic acid, aminobutanoic acid, aminopentanoic acid, aminohexanoic acid, aminoheptanoic acid, aminophenylacetic acid, and aminobenzoic acid. 4. The dispersion according to any one of 1 to 3.
  5. 　分散液中、前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩の含有量が、０．０１質量％以上２０質量％以下である、請求項１～４のいずれかに記載の分散液。 5. The dispersion according to any one of claims 1 to 4, wherein the content of the organic compound having an amino group and a carboxyl group and/or the hydrochloride thereof is 0.01% by mass or more and 20% by mass or less. dispersion.
  6. 　前記水素酸塩は、ハロゲン化水素酸塩である請求項１～５のいずれかに記載の分散液。 The dispersion according to any one of claims 1 to 5, wherein the hydrochloride is a hydrohalide.
  7. 　前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩が、脂肪族アミノ酸のハロゲン化水素酸塩又は芳香族アミノ酸のハロゲン化水素酸塩である請求項１～６のいずれかに記載の分散液。 7. The organic compound having an amino group and a carboxyl group and/or its hydrochloride is an aliphatic amino acid hydrohalide or an aromatic amino acid hydrohalide according to any one of claims 1 to 6. dispersion.
  8. 　前記配位子は、ハロゲン含有物質を含む請求項１～７のいずれかに記載の分散液。 The dispersion according to any one of claims 1 to 7, wherein the ligand contains a halogen-containing substance.
  9. 　分散液中の前記ペロブスカイト化合物及び／又はその前駆体の濃度が、０．１ｍｏｌ／ｄｍ３以上である請求項１～８のいずれかに記載の分散液。 9. The dispersion according to any one of claims 1 to 8, wherein the concentration of the perovskite compound and/or its precursor in the dispersion is 0.1 mol/dm 3 or more.
  10. 　分散液中の前記量子ドット（ただし、配位子なしに換算したもの）に対する前記アミノ基及びカルボキシ基を有する有機化合物及びその水素酸塩の質量比が、０．００１以上である請求項１～９のいずれかに記載の分散液。 Claims 1 to 1, wherein the mass ratio of the organic compound having an amino group and a carboxyl group and the hydrochloride thereof to the quantum dots in the dispersion (calculated without ligands) is 0.001 or more. 9. The dispersion according to any one of 9.
  11. 　分散液中の前記ペロブスカイト化合物及び／又はその前駆体に対する前記量子ドットの質量比が、０．１以上である請求項１～１０のいずれかに記載の分散液。 The dispersion according to any one of claims 1 to 10, wherein the mass ratio of the quantum dots to the perovskite compound and/or its precursor in the dispersion is 0.1 or more.
  12. 　光吸収層形成用である請求項１～１１のいずれかに記載の分散液。 The dispersion according to any one of claims 1 to 11, which is for forming a light absorption layer.
  13. 　請求項１～１２のいずれかに記載の分散液から得られる光吸収層。 A light absorbing layer obtained from the dispersion according to any one of claims 1 to 12.
  14. 　ペロブスカイト化合物と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を含有する光吸収層。 A light absorbing layer containing a perovskite compound, a quantum dot having a ligand, an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof.
  15. 　前記光吸収層中の前記量子ドットの含有量が、５ｖｏｌ％以上である、請求項１３又は１４に記載の光吸収層。 The light absorption layer according to claim 13 or 14, wherein the content of the quantum dots in the light absorption layer is 5 vol% or more.
  16. 　請求項１３～１５のいずれかに記載の光吸収層を有する光電変換素子。 A photoelectric conversion element having the light absorption layer according to any one of claims 13 to 15.
  17. 　請求項１６に記載の光電変換素子を有する太陽電池。 A solar cell comprising the photoelectric conversion element according to claim 16.
  18. 　前記ペロブスカイト化合物及び／又はその前駆体と、前記配位子を有する量子ドットと、前記アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を混合する、請求項１～１２のいずれかに記載の分散液の製造方法。 The perovskite compound and/or precursor thereof, the quantum dot having the ligand, and the organic compound having an amino group and a carboxyl group and/or a hydride thereof are mixed, according to any one of claims 1 to 12. A method for producing a dispersion according to any one of the above.
  19. 　ペロブスカイト化合物及び／又はその前駆体と、配位子を有する量子ドットと、アミノ基及びカルボキシ基を有する有機化合物及び／又はその水素酸塩と、を配合してなる、分散液。
          A dispersion obtained by blending a perovskite compound and/or its precursor, a quantum dot having a ligand, and an organic compound having an amino group and a carboxyl group and/or a hydrochloride thereof.
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