KR20200040517A - Composition for preparing hole transporting layer of organic-inorganic complex solar cell, organic-inorganic complex solar cell and manufacturuing method thereof - Google Patents

Abstract

A specification of the present invention provides a composition for forming a hole transport layer for an organic-inorganic composite solar cell including a Cu-based hole transport material and at least one metal oxide precursor of a vanadium oxide precursor, a molybdenum oxide precursor, and a tungsten oxide precursor, a manufacturing method of the organic-inorganic composite solar cell using the same and an organic-inorganic composite solar cell comprising a hole transport layer including the Cu-based hole transport material and at least one metal oxide of vanadium oxide, molybdenum oxide, and tungsten oxide.

Description

Composition for forming a hole transport layer of an organic-inorganic composite solar cell, a method of manufacturing an organic-inorganic composite solar cell and an organic-inorganic composite solar cell {COMPOSITION FOR PREPARING HOLE TRANSPORTING LAYER OF ORGANIC-INORGANIC COMPLEX SOLAR CELL, ORGANIC-INORGANIC COMPLEX SOLAR CELL AND MANUFACTURUING METHOD THEREOF}

The present specification relates to a composition for forming a hole transport layer of an organic-inorganic composite solar cell, an organic-inorganic composite solar cell, and a method of manufacturing the organic-inorganic composite solar cell.

In order to solve the global environmental problems caused by the depletion of fossil energy and its use, research on renewable and clean alternative energy sources such as solar energy, wind power, and hydropower has been actively conducted. Among them, interest in solar cells that directly change electrical energy from solar light is increasing. Here, a solar cell means a battery that absorbs light energy from sunlight and generates current-voltage using a photovoltaic effect that generates electrons and holes.

The organic-inorganic composite perovskite type solar cell has the advantage of being capable of high-efficiency and low-cost production based on the solution process, but has a problem of inferior durability compared to a competitive solar cell. There are various reasons for the decrease in durability, but there is no obvious alternative, especially with respect to the hole transport layer. In the case of Spiro-OMeTAD, which uses Li-based organo-metal complex (Li-TFSi) and tBP (tert-butylpyridine) as p-type dopants, the glass transition of Spiro-OMeTAD itself In spite of the high temperature, there is a problem that thermal stability is lowered, such as a glass transition temperature of less than 80 ° C when the additive is added to improve conductivity. There is a problem of deterioration of the light absorbing layer by the p-type dopant, and a method to replace it is required.

In order to solve this, attempts have been made to replace the hole transport layer based on an inorganic material having high conductivity and thermal stability, and Cu-based compounds have recently attracted attention. However, there is a problem of efficiency reduction due to the amount of interfacial properties with the electrode, and a method for solving the problem is needed.

Adv. Mater. 2014, 26, 4991-4998

The present specification provides a composition for forming a hole transport layer of an organic-inorganic composite solar cell, an organic-inorganic composite solar cell, and a method of manufacturing the organic-inorganic composite solar cell.

An exemplary embodiment of the present specification is a Cu-based hole transport material; And it provides a composition for forming a hole transport layer for an organic-inorganic composite solar cell comprising at least one metal oxide precursor of a vanadium oxide precursor, a molybdenum oxide precursor and a tungsten oxide precursor.

Another embodiment of the present specification

Preparing a first electrode;

Forming a light absorbing layer comprising a perovskite compound on the first electrode; And

Forming a second electrode on the light absorbing layer

In the method of manufacturing an organic-inorganic composite solar cell comprising a,

A method of manufacturing an organic-inorganic composite solar cell further comprising forming a hole transport layer between the first electrode and the light absorbing layer, or between the second electrode and the light absorbing layer using the composition according to the embodiment. to provide.

Another embodiment of the present specification

A first electrode; A second electrode; And a light absorbing layer provided between the first electrode and the second electrode and comprising a compound of perovskite structure, between the first electrode and the light absorbing layer, or Further comprising a hole transport layer provided between the second electrode and the light absorbing layer, the hole transport layer is a Cu-based hole transport material; And a metal oxide of at least one of vanadium oxide, molybdenum oxide, and tungsten oxide.

When forming a hole transport layer for an organic-inorganic composite solar cell using the composition for forming a hole transport layer for an organic-inorganic composite solar cell according to the exemplary embodiments of the present specification, process efficiency is excellent because a low temperature process and a solution process are possible, Not only is the electrical properties of the formed hole transport layer excellent, but also the charge injection / extraction properties when bonding with an electrode. Therefore, the organic-inorganic composite solar cell including the hole transport layer prepared using the composition has excellent charge injection characteristics, and thus has excellent battery efficiency.

1 and 2 illustrate a stacked structure of an organic-inorganic composite solar cell according to some exemplary embodiments of the present specification.
3 and 4 are diagrams showing color absorption according to CT (charge transfer) complex formation of CuSCN and a vanadium oxide precursor according to Reference Example 1.
5 to 7 are schematic diagrams showing the energy relationship of each layer of the device prepared in Experimental Example 1, Comparative Example 1 and Comparative Example 2, respectively.
8 is a graph showing the current density according to the voltage of the devices of Experimental Examples 1 and 2 and Comparative Examples 1 and 2.
9 and 10 are schematic diagrams showing the energy relationship of each layer of the device manufactured in Experimental Example 3 and Comparative Example 3, respectively.
11 is a graph showing the current density according to the voltage of the device of Experimental Example 3 and Comparative Example 3.

Hereinafter, the present specification will be described in detail.

In this specification, when it is said that a part "includes" a certain component, this means that other components may be further included instead of excluding other components unless otherwise specified.

In the present specification, when it is said that a member is positioned “on” another member, this includes not only the case where one member abuts another member, but also the case where another member is present between two members.

An exemplary embodiment of the present specification is a Cu-based hole transport material; And it provides a composition for forming a hole transport layer for an organic-inorganic composite solar cell comprising at least one metal oxide precursor of a vanadium oxide precursor, a molybdenum oxide precursor and a tungsten oxide precursor.

In the embodiment, as a composition for forming a hole transport layer for an organic-inorganic composite solar cell, together with a Cu-based hole transport material such as CuSCN (Copper (I) thiocyanate), at least one of a vanadium oxide precursor, a molybdenum oxide precursor, and a tungsten oxide precursor By including the metal oxide precursor of the final hole transport layer not only can be made to include all of at least one metal oxide of the Cu-based hole transport material and vanadium oxide, molybdenum oxide and tungsten oxide, 150 ℃ or less, preferably 100 ℃ A hole transport layer having the above-described composition can be formed by a solution process at a low temperature. The hole transport layer formed as described above can exhibit an inorganic-based p-type doping property, and thus not only has excellent electrical properties, but also has excellent interfacial properties with electrodes, particularly metal electrodes, and thus has excellent charge injection / extraction properties. In addition, since the above-described composition can exhibit high electrical conductivity even without high temperature heat treatment, it is possible to realize a very low process temperature of 150 ° C. or less, and the low temperature solution process can be performed at normal pressure, so that in the conventional high vacuum state Process economics can be greatly improved compared to deposition methods.

According to an exemplary embodiment of the present specification, the content of the metal oxide precursor in the composition for forming a hole transport layer for the organic-inorganic composite solar cell is 1 part by weight to 60 parts by weight, preferably 100 parts by weight, relative to 100 parts by weight of the Cu-based hole transport material It is preferably 1 to 50 parts by weight, more preferably 5 to 20 parts by weight. When the content of the metal oxide precursor is within the above range, conductivity is increased through formation of an effective Cu-based hole transport material and a charge transfer complex between the metal oxide precursor while maintaining the original characteristics of the Cu-based hole transport material. It is possible to simultaneously improve the charge injection characteristics with and the electrode. In the case of over-inclusion, it is preferable to set a concentration range in which such a phenomenon does not occur because it may cause a decrease in the open voltage due to a decrease in coating properties and a probabilistic increase in interface contact with a metal oxide.

The Cu-based hole transport material is not particularly limited as long as it contains Cu and can be used as a hole transport material in an organic-inorganic composite solar cell application.

For example, the Cu-based hole transport material may include those selected from CuSCN, Cu halides, and Cu-added oxides, and specifically selected from CuSCN, CuI, CuBr, and Cu: NiO (Cu doped NiO). You can use things that include. Specifically, the Cu-based hole transport material is preferably CuSCN.

The above-described metal oxide precursor is a material that provides a metal oxide when heat treatment at 150 ° C. or less after dissolving in a solvent is not particularly limited as long as it is a material capable of such an action. For example, as the metal oxide precursor, vanadium (V) oxytriethoxide, vanadium (V) oxychloride, vanadium (V) oxytripropoxide, vanadium (V) oxytriisopropoxide, Mo (V) ethoxy Side, Mo (VI) oxide bis (2,4-pentanedionate), W (V) ethoxide, W (VI) oxychloride, W (VI) dichloride dioxide (WO ₂ Cl ₂ ), etc. can be used. .

The composition for forming a hole transport layer for an organic-inorganic composite solar cell according to the embodiment includes a Cu-based hole transport material; And a solvent in which the metal oxide precursor is dissolved.

At this time, the solvent is not particularly limited as long as it can dissolve the Cu-based hole transport material and the metal oxide precursor. For example, the solvent preferably has a solubility at room temperature for the Cu-based hole transport material of 10 mg / ml or more, preferably 30 mg / ml or more, preferably 45 mg / ml or more, and the higher the solubility, the better. .

The solvent is preferably 0.1 μl / 100 μl or more solubility at room temperature for the metal oxide precursor (specific gravity ~ 1.03), preferably 3 μl / 100 μl or more, and may be 4 μl / 100 μl or more, and high solubility The better.

The solvent is not particularly limited, but for the low-temperature solution process, the boiling point is preferably 150 ° C or lower, and more preferably 100 ° C or lower.

According to an exemplary embodiment, as the solvent, a polar solvent such as n-alkyl sulfide, such as diethyl sulfide, dipropyl sulfide, dibutyl sulfide, and the like, acetonitrile with HCl (1 wt%) may also be used, It is not limited to this. According to one embodiment, the solvent may be 40% by weight or more, for example, 50% by weight or more, and 99% by weight or less based on 100% by weight of the composition for forming a hole transport layer for an organic-inorganic composite solar cell. The sum of the content of the Cu-based hole transport material and the metal oxide precursor based on 100% by weight of the composition for forming a hole transport layer for the organic-inorganic composite solar cell is preferably 1% by weight or more and 60% by weight or less, and 50% by weight or less It is preferred.

Another embodiment of the present specification relates to a method of manufacturing an organic-inorganic composite solar cell, comprising: preparing a first electrode; Forming a light absorbing layer comprising a perovskite compound on the first electrode; And forming a second electrode on the light absorbing layer, further using a composition according to the above-described embodiments between the first electrode and the light absorbing layer, or between the second electrode and the light absorbing layer. And forming a hole transport layer.

According to an exemplary embodiment, the step of forming the hole transport layer may be performed by a solution process at 150 ° C or less, preferably 100 ° C or less. As a solution process, a coating method known in the art may be used, for example, spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, etc. may be used. , It is not limited to this.

The process temperature is 150 ° C. or less, preferably 100 ° C. or less, and can be performed at room temperature to 100 ° C. or less, preferably 40 ° C. to 100 ° C. or less, such as 45 ° C. to 70 ° C. or less. The process time may be determined according to the process temperature or coating amount, the type or content of the solvent, and may be performed, for example, from 0.5 minutes to 60 minutes.

The coating amount for forming the hole transport layer is determined by the thickness of the hole transport layer to be finally obtained, the solvent content in the composition, the area of the hole transport layer, etc., for example, 10 μl to 1,000 μl may be coated, but is not limited to this. no.

According to one embodiment, the step of forming the hole transport layer is after the step of forming the light absorbing layer, the composition is applied on the light absorbing layer by a solution process, preferably 150 ° C. or less, preferably 100 ° C. It may be performed by heat treatment below.

In addition to the hole transport layer, materials and manufacturing methods of the first electrode, the second electrode, and the light absorbing layer may use techniques known in the art. If necessary, an additional layer may be introduced in addition to the first electrode, the second electrode, and the light absorbing layer.

Another exemplary embodiment of the present specification is a first electrode; A second electrode; And a light absorbing layer provided between the first electrode and the second electrode and comprising a compound of perovskite structure, between the first electrode and the light absorbing layer, or Further comprising a hole transport layer provided between the second electrode and the light absorbing layer, the hole transport layer is a Cu-based hole transport material; And a metal oxide of at least one of vanadium oxide, molybdenum oxide, and tungsten oxide.

According to one embodiment, the content of at least one metal oxide of vanadium oxide, molybdenum oxide, and tungsten oxide in the hole transport layer is 1 part by weight to 60 parts by weight, preferably 1 part by weight, relative to 100 parts by weight of the Cu-based hole transport material Parts to 50 parts by weight, more preferably 5 to 20 parts by weight.

According to one embodiment, the hole transport layer has an absorption peak at about 600 nm and about 1500 nm. The above-described metal oxide may be incorporated into a Cu-based hole transport material (DOPING) to form a charge transfer complex (CT), thereby having the above absorption spectrum.

According to one embodiment, the thickness of the hole transport layer is 10 nm to 1,000 nm. When the thickness of the hole transport layer satisfies the above range, a uniform film can be formed on the lower layer without defects such as pinholes, and the contact between the upper electrode and the lower insertion layer can be prevented to obtain a device structure that can be effectively driven. .

According to one embodiment, the hole transport layer is 150 ℃ or less, preferably 100 ℃ It is formed by the solution process below. The method for manufacturing the hole transport layer follows the above description.

The light absorbing layer includes a compound having a perovskite structure. As a compound of perovskite structure, those known in the art can be used without limitation.

In one embodiment of the present specification, the compound of the perovskite structure is represented by any one of the following Chemical Formulas 1 to 3.

[Formula 1]

R1M1X1 ₃

[Formula 2]

R2 _a R3 _(1-a) M2X2 _z X3 _(3-z)

[Formula 3]

R4 _b R5 _c R6 _d M3X4 _{z '} X5 _(3-z')

In Chemical Formulas 1 to 3,

R2 and R3 are different from each other,

R4, R5 and R6 are different from each other,

R1 to R6 are each independently C _n H _{2n + 1} NH ₃ ⁺ , NH ₄ ⁺ , HC (NH ₂ ) ₂ ⁺ , Cs ⁺ , Rb ⁺ , NF ₄ ⁺ , NCl ₄ ⁺ , PF ₄ ⁺ , PCl ₄ ⁺ , CH ₃ PH ₃ ⁺ , CH ₃ AsH ₃ ⁺ , CH ₃ SbH ₃ ⁺ , PH ₄ ⁺ , AsH ₄ ⁺ and SbH ₄ ⁺ is a monovalent cation selected from,

M1 to M3 are the same as or different from each other, and each independently Cu ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , Cr ²⁺ , Pd ²⁺ , Cd ²⁺ , Ge ²⁺ , Sn ^{Is a} divalent metal ion selected from ²⁺ , Bi ²⁺ , Pb ²⁺ and Yb ²⁺ ,

X1 to X5 are the same as or different from each other, and each independently a halogen ion,

n is an integer from 1 to 9,

a is a real number of 0 <a <1,

b is a real number of 0 <b <1,

c is a real number in 0 <c <1,

d is a real number of 0 <d <1,

b + c + d is 1,

z is a real number of 0 <z <3,

z 'is a real number of 0 <z' <3.

In one embodiment of the present specification, the compound of the perovskite structure of the light absorbing layer may include a single cation. In the present specification, a single cation means that one type of monovalent cation is used. That is, in Formula 1, R1 means that only one type of monovalent cation was selected. For example, R1 in Chemical Formula 1 is C _n H _{2n + 1} NH ₃ ⁺ , and n may be an integer from 1 to 9.

In one embodiment of the present specification, the compound of the perovskite structure of the light absorbing layer may include a complex cation. In the present specification, the complex cation means that two or more kinds of monovalent cations are used. That is, in Formula 2, it is meant that a monovalent cation in which R2 and R3 are different from each other is selected, and a monovalent cation in which R4 to R6 are different from each other in Formula 3 is selected. For example, R2 in Chemical Formula 2 may be C _n H _{2n + 1} NH ₃ ⁺ , and R3 may be HC (NH ₂ ) ₂ ⁺ . In addition, R4 in Chemical Formula 3 may be C _n H _{2n + 1} NH ₃ ⁺ , R5 may be HC (NH ₂ ) ₂ ⁺ , and R6 may be Cs ⁺ .

In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 1.

 In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 2.

In one embodiment of the present specification, the compound of the perovskite structure is represented by Chemical Formula 3.

In one embodiment of the present specification, R1 to R6 are each C _n H _{2n + 1} NH ₃ ⁺ , HC (NH ₂ ) ₂ ⁺ or Cs ⁺ . At this time, R2 and R3 are different from each other, and R4 to R6 are different from each other.

In one embodiment of the present specification, R1 is CH ₃ NH ₃ ⁺ , HC (NH ₂ ) ₂ ⁺ or Cs ⁺ .

In one embodiment of the present specification, R2 and R4 are each CH ₃ NH ₃ ⁺ .

In one embodiment of the present specification, R3 and R5 are each HC (NH ₂ ) ₂ ⁺ .

In one embodiment of the present specification, R6 is Cs ⁺ .

In one embodiment of the present specification, M1 to M3 are each Pb ²⁺ .

In one embodiment of the present specification, X2 and X3 are different from each other.

In one embodiment of the present specification, X4 and X5 are different from each other.

In one embodiment of the present specification, X1 to X5 are F or Br, respectively.

In an exemplary embodiment of the present specification, in order that the sum of R2 and R3 becomes 1, a is a real number of 0 <a <1. Also, in order that the sum of X2 and X3 becomes 3, z is a real number of 0 <z <3.

In one embodiment of the present specification, in order for the sum of R4, R5, and R6 to become 1, b is a real number of 0 <b <1, c is a real number of 0 <c <1, and d is 0 <d <1 is a real number, and b + c + d is 1. In addition, in order that the sum of X4 and X5 becomes 3, z 'is a real number of 0 <z' <3.

In one embodiment of the present specification, the compound of the perovskite structure is CH ₃ NH ₃ PbI ₃ , HC (NH ₂ ) ₂ PbI _3, CH ₃ NH ₃ PbBr ₃ , HC (NH ₂ ) ₂ PbBr ₃ , (CH ₃ NH ₃ ) _a (HC (NH ₂ ) ₂ ) _(1-a) PbI _z Br _(3-z) or (HC (NH ₂ ) ₂ ) _b (CH ₃ NH ₃ ) _c Cs _d PbI _{z '} Br _(3-z') , a is a real number of 0 <a <1, b is a real number of 0 <b <1, c is a real number of 0 <c <1, d is a real number of 0 <d <1, b + c + d is 1, z is a real number of 0 <z <3, z 'is a real number of 0 <z'<3 .

In one embodiment of the present specification, the thickness of the light absorbing layer is 100 nm to 1 μm.

In one embodiment of the present specification, the light absorbing layer may be introduced through spin coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, thermal evaporation, or the like.

In one embodiment of the present specification, an electron transport layer may be further included between the first electrode and the light absorbing layer.

In one embodiment of the present specification, the organic-inorganic composite solar cell has an n-i-p structure.

 In the present specification, the nip structure includes a structure in which a first electrode, a light absorbing layer, a hole transport layer and a second electrode are sequentially stacked, or a first electrode, an electron transport layer, a light absorbing layer, an insertion layer, a hole transport layer and a second electrode are sequentially It refers to a layered structure.

1 and 2 show an organic-inorganic composite solar cell according to an exemplary embodiment of the present specification. Specifically, FIG. 1 shows an organic-inorganic composite solar cell in which the first electrode 10, the light absorbing layer 20, the hole transport layer 30, and the second electrode 40 are sequentially stacked. 2 shows an organic-inorganic composite solar cell in which the first electrode 10, the electron transport layer 50, the light absorbing layer 20, the hole transport layer 30, and the second electrode 40 are sequentially stacked.

In one embodiment of the present specification, the organic-inorganic composite solar cell may further include a substrate under the first electrode.

In one embodiment of the present specification, the substrate may be a substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness. Specifically, a glass substrate, a thin glass substrate, or a plastic substrate can be used. The plastic substrate has a flexible film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone and polyimide in the form of a single layer or multiple layers. Can be included. However, the substrate is not limited thereto, and a substrate commonly used in organic-inorganic composite solar cells may be used.

In the present specification, the first electrode may be an anode, and the second electrode may be a cathode. Further, the first electrode may be a cathode, and the second electrode may be an anode.

In one embodiment of the present specification, the first electrode is a transparent electrode, and the solar cell may absorb light through the first electrode.

In one embodiment of the present specification, when the first electrode is a transparent electrode, the first electrode is polyethylene terephthalate (PET), polyethylene naphthelate (PEN), poly, in addition to glass and quartz plates Propylene (polyperopylene, PP), polyimide (PI), polycarbonate (PC), polystylene (PS), polyoxyethlene (POM), AS resin (acrylonitrile styrene copolymer), ABS resin ( The conductive material may be doped with a flexible and transparent material such as acrylonitrile butadiene styrene copolymer, triacetyl cellulose (TAC), and polyarylate (PAR). Specifically, the first electrode is indium tin oxide (ITO), fluorine doped tin oxide (FTO), aluminum doped zinc oxide (aluminium doped zink oxide, AZO), IZO (indium tin oxide) zinc oxide), ZnO-Ga ₂ O ₃ , ZnOAl ₂ O ₃ and antimony tin oxide (ATO), and more specifically, the first electrode may be ITO.

In one embodiment of the present specification, the first electrode may be a translucent electrode. When the first electrode is a semi-transparent electrode, it may be made of a metal such as silver (Ag), gold (Au), magnesium (Mg) or alloys thereof.

In the present specification, the electron transport layer may include a metal oxide. Metal oxide is specifically, Ti oxide, Zn oxide, In oxide, Sn oxide, W oxide, Nb oxide, Mo oxide, Mg oxide, Zr oxide, Sr oxide, Yr oxide, La oxide, V oxide, Al oxide, Y oxide , Sc oxide, Sm oxide, Ga oxide, SrTi oxide and one or more selected from these composites may be used, but is not limited thereto.

Hereinafter, examples will be described in detail to specifically describe the present specification. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present specification is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

Reference Example 1.

Color change was confirmed when CuSCN and a vanadium oxide precursor were mixed.

Specifically, after dissolving CuSCN (powder) in diethyl sulfide (98% purity) (concentration: 35 mg / ml), 10% by weight of vanadium oxytriisopropoxide, respectively (based on 100% by weight of the total composition) , Hereinafter the same) and 20% by weight and stirred until completely dissolved. Subsequently, after filtering with a PP (polypropylene) filter, the absorption spectrum according to the wavelength of the well-mixed solution was measured. FIG. 3 is a visual observation of the color change of the solution before and after mixing of vanadium oxytriisopropoxide, and FIG. 4 shows the solution as a substrate using a glass having a thickness of about 20 nm, followed by wavelength. It shows the measurement result of the absorption spectrum.

The role of vanadium oxide in Reference Example 1 is to be incorporated into CuSCN (DOPING) to form a charge transfer complex (CT). The method of qualitatively confirming this is a method of visually confirming (the color changes because the absorption changes due to the formation of the CT complex), or similarly, by checking the absorption spectrum to confirm whether a characteristic peak thought to be CT absorption is formed. . Therefore, there is a possibility that there is a possibility that there is no absorption peak due to CT unless the color is usually changed, so there is a case that it is not effective.

It could be expected that CuSCN and the vanadium oxide precursor were formed by forming a CT (charge transfer) complex through the color change of the solution of FIG. 3.

According to FIG. 4, it was confirmed that absorption peaks were formed at about 600 nm and about 1500 nm, and it was confirmed that the mechanism that the CuSCN and the vanadium oxide precursor form a CT (charge transfer) complex is effective.

Comparative Reference Example 1

It was carried out in the same manner as in Reference Example 1, except that Spiro-OMeTAD was used instead of CuSCN. Unlike Reference Example 1, it was confirmed that there was no color change before and after mixing the vanadium oxide precursor.

<Hole only device fabrication>

Comparative Example 1:

1) An alkali-free glass substrate sputtered with tin indium oxide (ITO) was washed with acetone and isopropyl alcohol.

2) Formation of hole transport layer (CuSCN)

CuSCN (powder) was stirred until completely dissolved in diethyl sulfide (98%). After filtering with a PP filter, 100 μl of the well-mixed solution was applied onto tin indium oxide (ITO), spin-coated at 5,000 rpm, and heat-treated at 50 ° C. for 10 minutes.

3) Electrode formation:

Au was vacuum deposited to a thickness of 70 nm.

The energy relationship between each layer of the device manufactured in Comparative Example 1 is shown in FIG. 6. The unit of the numerical value in FIG. 6 is eV.

Comparative Example 2:

1) An alkali-free glass substrate sputtered with tin indium oxide (ITO) was washed with acetone and isopropyl alcohol.

2) Formation of the first hole transport layer (CuSCN)

CuSCN (powder) was stirred in diethyl sulfide (98%) until completely dissolved. After filtering with a PP filter, 100 μl of a well-mixed solution was applied on tin indium oxide (ITO), spin-coated at 5000 rpm, and heat-treated at 50 ° C. for 10 minutes.

3) Formation of the second hole transport layer (Spiro-OMeTAD)

After dissolving Spiro-OMeTAD in chlorobenzene (concentration: 80 mg / ml), 17.5 μl of Li (TFSi) acetonitrile solution (520 mg / ml) and 28.5 μl of tBP were added, and 100 μl of the well-mixed solution was added to the first hole. It was applied on the transport layer and spin coated at 5000 rpm.

4) Electrode formation:

Au was vacuum deposited to a thickness of 70 nm.

The energy relationship between each layer of the device manufactured in Comparative Example 2 is shown in FIG. 7. The unit of the numerical value in FIG. 7 is eV.

Experimental Example 1

1) An alkali-free glass substrate sputtered with tin indium oxide (ITO) was washed with acetone and isopropyl alcohol.

2) First hole transport layer formation (CuSCN):

CuSCN (powder) was stirred in diethyl sulfide (98%) until completely dissolved. After filtering with a PP filter, 100 μl of a well-mixed solution was applied onto tin indium oxide (TIO), spin-coated at 5000 rpm, and then heat-treated at 50 ° C. for 10 minutes.

3) Formation of a second hole transport layer (p-doped CuSCN):

After dissolving CuSCN (powder) in diethyl sulfide (98%) (concentration: 35 mg / ml), 4 μl of vanadium oxytriisopropoxide was mixed and stirred until completely dissolved. After filtering with a PP filter, 100 μl of the well-mixed solution was applied onto the first hole transport layer (CuSCN) and spin-coated at 5000 rpm. Then, depending on the heat treatment temperature, heat treatment was performed at 50 ° C for 10 minutes.

4) Electrode formation:

Au was vacuum deposited to a thickness of 70 nm.

The energy relationship between each layer of the device fabricated in Experimental Example 1 is shown in FIG. 5. The unit of the numerical value in FIG. 5 is eV.

Experimental Example 2

When forming the first and second hole transport layers, the heat treatment conditions were performed in the same manner as in Experimental Example 1, except that the conditions were performed at 100 ° C for 10 minutes.

Comparative Examples 1 and 2 and Experimental Examples 1 and 2 are examples of fabrication of a hole only (single carrier) device, and the current density according to the voltage of the device is shown in FIG. 8. As in Comparative Example 1, the current density increase of 100 times or more was confirmed in Experimental Examples 1 and 2 compared to the device in which the Au electrode was applied to the CuSCN monolayer. Therefore, it was found that the charge injection characteristics of the p-doped CuSCN of the experimental examples with the metal electrode showed a very superior characteristic compared to the CuSCN alone. As in Comparative Example 2, it was confirmed that Experimental Examples 1 and 2 had more than 10 times better properties than the device using Spiro-OMeTAD (organic hole transport layer, hole transport layer generally used for perovskite) for the same purpose. .

<Solar cell device fabrication>

Comparative Example 3:

1) An alkali-free glass substrate sputtered with tin indium oxide (ITO) was washed with acetone and isopropyl alcohol.

2) Formation of electron transport layer:

SnCl. 250 μl of the precursor (0.1M) solution was spin-coated at a rate of 2,000 rpm, followed by heat treatment at 200 ° C. for 1 hour.

3) Formation of perovskite layer:

Perovskite precursor ((HC (NH2) 2) x (CH3NH3) yCs1-x-yPbIzBr3-z (0 <x <1, 0 <y <1, 0.8 <x + y <1, 0 <z <3 )) And the solution in which 0.05 wt% of a fluorine-based surfactant (3M, FC-4430) was dissolved in dimethylformamide (dimethylforrmarmide) compared to the perovskite precursor was spin-coated at 5,000 rpm, and then heat-treated at 150 ° C for 30 minutes. .

4) Formation of hole transport layer (CuSCN)

The CNSCN (powder) was stirred in diethyl sulfide (98%) until completely dissolved. Thereafter, 100 μl of the well-mixed solution with a PP filter was applied on the perovskite layer, spin-coated at 5,000 rpm, and heat-treated at 50 ° C. for 10 minutes.

5) Electrode formation:

Au was vacuum deposited to a thickness of 70 nm.

The energy relationship between each layer of the device manufactured in Comparative Example 3 is shown in FIG. 10. The unit of the numerical value in FIG. 10 is eV.

Experimental Example 3:

1) An alkali-free glass substrate sputtered with tin indium oxide (ITO) was washed with acetone and isopropyl alcohol.

2) Formation of electron transport layer:

SnCl. 250 μl of the precursor (0.1M) solution was spin-coated at a rate of 2,000 rpm, followed by heat treatment at 200 ° C. for 1 hour.

3) Formation of perovskite layer:

Perovskite precursor ((HC (NH2) 2) x (CH3NH3) yCs1-x-yPbIzBr3-z (0 <x <1, 0 <y <1, 0.8 <x + y <1, 0 <z <3 )) And the solution in which 0.05 wt% of a fluorine-based surfactant (3M, FC-4430) was dissolved in dimethylformamide (dimethylforrmarmide) compared to the perovskite precursor was spin-coated at 5,000 rpm, and then heat-treated at 150 ° C for 30 minutes. .

4) Formation of hole transport layer (p-doped CuSCN)

After dissolving CuSCN (powder) in diethyl sulfide (98%) (concentration: 35 mg / ml), 4 μl of vanadium oxytriisopropoxide was mixed and stirred until completely dissolved. After filtering with a PP filter, 100 μl of the well-mixed solution was applied on a perovskite layer and spin-coated at 5,000 rpm to form a thin film, followed by heat treatment at 50 ° C. for 10 minutes.

6) Electrode formation:

Au was vacuum deposited to a thickness of 70 nm.

The energy relationship between each layer of the device fabricated in Experimental Example 3 is shown in FIG. 9. The unit of the numerical value in FIG. 9 is eV.

The properties of the devices of Comparative Example 3 and Experimental Example 3 are shown in Table 1 and FIG. 11 below.

Short circuit current (Jsc)
(mA / cm ² ) Open voltage (Voc)
(V) Filling rate (FF)
(%) Efficiency (η)
(%) Comparative Example 3 18.1 1.04 57.3 10.8 Experimental Example 3 20.4 1.03 68.7 14.4

In Comparative Example 3, it was confirmed that the short-circuit current, open voltage, filling rate, efficiency, and current density characteristics were significantly superior to Comparative Example 3.

<Measurement method of Table 1 and FIG. 11>

The solar cell performance of the comparative example and the experimental example was measured using a general solar measurement system. First, the AAA grade solar simulator was turned on and left for 30 minutes to stabilize the light source. After adjusting the light intensity to output 1 sun (100 mW / cm ² ) as a calibrated standard cell, measure the experimental sample in the Source Measure Unit (Keithly 2420) to which the computer is connected, connect the Jig with a solar simulator It was placed in and measured. The measurement conditions were set to 100 data points with a voltage range of 0 to 1.2 V and a scan speed of 100 msec.

Efficiency was calculated by obtaining the values shown in Table 1 from the voltage-current data obtained in the above configuration. In Table 1, V _OC is an open voltage, J _SC is a short-circuit current, FF is a fill factor, and η is an energy conversion efficiency. The open voltage and short-circuit current are the X-axis and Y-axis intercepts in the quadrant of the voltage-current density curve, respectively, and the higher these two values, the higher the efficiency of the solar cell is. In addition, the fill factor is a value obtained by dividing the area of the rectangle that can be drawn inside the curve by the product of the short-circuit current and the open voltage. The energy conversion efficiency (η) can be obtained by dividing the product of the open voltage (Voc), short-circuit current (Jsc), and charging rate (FF) by the intensity of the incident light (Pin), and the higher the value, the more preferable.

10: first electrode
20: light absorbing layer
30: hole transport layer
40: second electrode
50: electron transport layer

Claims (16)

Cu-based hole transport material; And a metal oxide precursor of at least one of a vanadium oxide precursor, a molybdenum oxide precursor, and a tungsten oxide precursor. The composition for forming a hole transport layer for an organic-inorganic composite solar cell according to claim 1, wherein the content of the metal oxide precursor is 1 part by weight to 60 parts by weight compared to 100 parts by weight of the Cu-based hole transport material. The method according to claim 1, The Cu-based hole transport material is a composition for forming a hole transport layer for an organic-inorganic composite solar cell comprising one selected from CuSCN, Cu halide, and Cu-added oxide. The composition for forming a hole transport layer for an organic-inorganic composite solar cell according to claim 3, wherein the Cu-based hole transport material comprises one selected from CuSCN, CuI, CuBr, and Cu: NiO (Cu doped NiO). The method according to claim 1, The metal oxide precursor is vanadium (V) oxytriethoxide, vanadium (V) oxychloride, vanadium (V) oxytripropoxide, vanadium (V) oxytriisopropoxide, Mo ( V) with ethoxide, Mo (VI) oxide bis (2,4-pentanedionate), W (V) ethoxide, W (VI) oxychloride, and W (VI) dichloride dioxide (WO ₂ Cl ₂ ) A composition for forming a hole transport layer for an organic-inorganic composite solar cell, comprising one selected from the group consisting of. The composition according to claim 1, wherein the composition further comprises a solvent in which the Cu-based hole transport material and the metal oxide precursor are dissolved. Preparing a first electrode;
Forming a light absorbing layer comprising a perovskite compound on the first electrode; And
Forming a second electrode on the light absorbing layer
In the method of manufacturing an organic-inorganic composite solar cell comprising a,
An organic-inorganic composite solar cell further comprising forming a hole transport layer between the first electrode and the light absorbing layer, or between the second electrode and the light absorbing layer using the composition according to claim 1. Method of manufacturing. The method of claim 7, wherein the step of forming the hole transport layer is performed by a solution process at 150 ° C. or less. The method according to claim 7, The step of forming the hole transport layer is after the step of forming the light-absorbing layer, the composition is applied to the light-absorbing layer by a solution process, and is performed by heat treatment at 150 ℃ or less-organic-inorganic Method of manufacturing a composite solar cell. A first electrode; A second electrode; And a light absorbing layer provided between the first electrode and the second electrode and comprising a compound of perovskite structure, between the first electrode and the light absorbing layer, or Further comprising a hole transport layer provided between the second electrode and the light absorbing layer, the hole transport layer is a Cu-based hole transport material; And a metal oxide of at least one of vanadium oxide, molybdenum oxide, and tungsten oxide. The organic-inorganic composite solar cell of claim 10, wherein the content of the metal oxide in the hole transport layer is 1 part by weight to 60 parts by weight compared to 100 parts by weight of the Cu-based hole transport material. The organic-inorganic composite solar cell of claim 10, wherein the hole transport layer is formed by a solution process at 150 ° C or less. The organic-inorganic composite solar cell of claim 10, wherein the hole transport layer has an absorption peak at about 600 nm and about 1500 nm. The organic-inorganic composite solar cell of claim 10, wherein the Cu-based hole transport material comprises one selected from CuSCN, Cu halide, and Cu-added oxide. 15. The organic-inorganic composite solar cell of claim 14, wherein the Cu-based hole transport material comprises one selected from CuSCN, CuI, CuBr, and Cu: NiO (Cu doped NiO). The method according to claim 10, wherein the metal oxide is vanadium (V) oxide, Mo (V) oxide, Mo (VI) oxide, W (V) oxide and W (VI) oxide, including those selected from the group consisting of -Inorganic composite solar cell.

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