JP2004119305A - Photoelectric conversion element and photoelectric conversion element module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion element for easily manufacturing a solar cell module and a solar cell array, and to provide a photoelectric conversion element module using the same. <P>SOLUTION: This photoelectric conversion element 1 is equipped with a first electrode 5 coated with a sensitizing-dye carrying semiconductor layer 7, a second electrode 15 standing opposite to the semiconductor layer 7 of the first electrode 5, and an electrolyte layer 13 disposed between the semiconductor layer 7 of the first electrode 5 and the second electrode 15. The first and second electrodes 5 and 15 are equipped with connection terminal parts 5a and 21a, respectively. The terminal parts 5a and 21a of the first and second electrodes 5 and 15, respectively, are disposed on a same plane. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a photoelectric conversion element used for a dye-sensitized solar cell or the like and a photoelectric conversion element module using the same.
[0002]
[Prior art]
A new type of dye-sensitized solar cell proposed by Gretzel et al. Has attracted attention because of its dramatically higher conversion efficiency (on the order of 7%) than conventional dye-sensitized solar cells. The dye-sensitized solar cell realizes photoelectric conversion by injecting excited electrons generated by a dye that captures light into a semiconductor. Therefore, it is important to carry a large amount of the sensitizing dye on the semiconductor in order to increase the light collecting power, and to inject electrons from the sensitizing dye into the semiconductor as soon as possible. This new dye-sensitized solar cell, also called a Gretzell cell, solves this problem by supporting a ruthenium complex as a sensitizing dye on a porous film made of ultrafine titanium oxide (for example, See Patent Document 1.).
[0003]
[Non-patent document 1]
Gratzel, 1 other, "Nature" (UK), October 24, 1991, Volume 353, p. 737-740
This Grettzel cell can be assembled simply by applying a paste in which ultrafine particles of titanium oxide are dispersed to a transparent electrode, carrying a sensitizing dye, and filling an electrolyte between the counter electrode and the transparent electrode. Compared to conventional solar cells, they can be manufactured with simpler devices, and are attracting attention as one of next-generation solar cells.
[0004]
By the way, the current Gretzell cell has an open-circuit voltage of 1 V or less on its own, and in order to drive a practical electric device with the Gretzell cell, it is necessary to increase the output voltage by connecting a plurality of cells in series. Required. Several module structures in which Gretzell cells are connected in series have already been proposed (for example, see Patent Documents 1 and 2).
[0005]
[Patent Document 1]
Japanese Unexamined Patent Publication No. Hei 11-514787
[Patent Document 2]
WO 96/29716 (Patent Document 1) proposes a structure constituting a module connected in series on one substrate and a method of manufacturing the same. A typical Grettzel cell has a sandwich structure in which an electrolyte is interposed between a photoelectrode and a counter electrode, and requires two substrates. On the other hand, the structure described in Patent Document 1 can reduce the number of substrates to one, and has advantages such as weight reduction and cost reduction.
[0007]
Further, Patent Document 2 proposes a method in which a photovoltaic electrode and a counter electrode of two adjacent elements are connected in series in a sandwich structure cell while inverting the photoelectrode and the counter electrode. This structure has an advantage that it can be easily connected in series.
[0008]
However, the above-mentioned structure using one substrate is a module structure suitable for a silicon-based solar cell manufactured by a dry process. However, when a Gretzell cell is manufactured by a wet process, it is necessary to connect adjacent elements. There is a problem that it is very difficult to apply electrodes.
[0009]
Also, in the method of serially connecting the photoelectrode and the counter electrode of two adjacent elements while inverting them, the element having the photoelectrode as the light receiving surface and the element having the counter electrode as the light receiving surface are connected in series. However, there is a problem that the output characteristic of the device is limited to an element having a light receiving surface with a counter electrode having poor photoelectric conversion efficiency.
[0010]
[Problems to be solved by the invention]
In addition to Gretzell cells, solar cells can be made into solar cell modules by expanding the area by connecting multiple solar cells in actual use, and connecting the required number of solar cells to form a solar cell array. The desired output has been obtained. As shown in FIG. 5, the Gretzell cell has a structure in which the transparent electrode 5 and the counter electrode 15 face each other due to its configuration. Therefore, the external connection terminal portions 5a attached to the transparent electrode 5 and the counter electrode 15, respectively. 15a are directed in opposite directions. Therefore, when configuring a solar cell module or a solar cell array, it is difficult to connect and connect the solar cells as they are. For example, when a series module is manufactured by arranging and connecting solar cells having the structure of FIG. 5, it is necessary to make connection using connection leads 23 such as silver paste or soldering as shown in FIG. 6. At this time, if the transparent electrode 5 and the counter electrode 15 have a structure facing each other, it is difficult to perform an electrical connection operation from one direction of the connection terminal portions 5a and 15a. Further, the reinforcement work for suppressing the separation of the connection portion cannot be easily performed, and it is difficult to secure the necessary strength as a module.
[0011]
The present invention proposes a structure in which electrical connection between photoelectric conversion elements can be easily and reliably performed, and a photoelectric conversion element capable of easily manufacturing a solar cell module and a solar cell array, and a photoelectric conversion using the same. An element module is provided.
[0012]
[Means for Solving the Problems]
The photoelectric conversion element of the present invention includes a first electrode on which a semiconductor layer supporting a sensitizing dye is attached, a second electrode facing the semiconductor layer of the first electrode, A photoelectric conversion element including a semiconductor layer and an electrolyte layer disposed between the second electrode,
The first electrode and the second electrode each include a connection terminal portion,
The connection terminal portion of the first electrode and the connection terminal portion of the second electrode are arranged on the same plane.
[0013]
The photoelectric conversion element module of the present invention is a photoelectric conversion element module in which a plurality of the photoelectric conversion elements are electrically connected,
A connection terminal portion of a first electrode of the photoelectric conversion element is electrically connected to a connection terminal portion of a second electrode of another photoelectric conversion element adjacent thereto.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0015]
One embodiment of the photoelectric conversion element of the present invention includes a first electrode on which a semiconductor layer carrying a sensitizing dye is attached, a second electrode facing the semiconductor layer of the first electrode, A photoelectric conversion element including a semiconductor layer of one electrode and an electrolyte layer disposed between the second electrode and the semiconductor layer. The first electrode and the second electrode each include a connection terminal, and the connection terminal of the first electrode and the connection terminal of the second electrode are on the same plane. Are located.
[0016]
More specifically, the first electrode and the second electrode are each formed on a substrate, and the connection terminal of the first electrode and the connection terminal of the second electrode are the same. It is arranged on the substrate.
[0017]
Since the connection terminal portion of the first electrode and the connection terminal portion of the second electrode are on the same plane, electrical connection between the photoelectric conversion elements can be easily and reliably performed from the same direction.
[0018]
One embodiment of the photoelectric conversion element module of the present invention is a photoelectric conversion element module in which a plurality of the above-described photoelectric conversion elements are electrically connected, and a connection terminal of a first electrode of the photoelectric conversion element. And a connection terminal portion of a second electrode of another photoelectric conversion element adjacent to the portion.
[0019]
By electrically connecting the connection terminal portion of the first electrode and the connection terminal portion of the second electrode using the photoelectric conversion element arranged on the same plane, the photoelectric conversion element module can be easily and reliably connected. Can be formed.
[0020]
Preferably, the connection terminal of the first electrode and the connection terminal of the second electrode are electrically connected via a metal conductor. This is because the connection strength can be increased.
[0021]
Further, it is preferable that the metal conductor is covered with a conductive film. This is because electrical connection between the photoelectric conversion elements becomes more reliable. The conductive film can be formed by applying a conductive paint, vacuum-depositing a conductive substance, soldering, or the like.
[0022]
Next, an embodiment of the present invention will be described with reference to the drawings.
[0023]
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of one embodiment of the photoelectric conversion element of the present invention, in which connection terminals of a positive electrode and a negative electrode are arranged on a transparent substrate 3. In FIG. 1, the photoelectric conversion element 1 includes a transparent electrode 5 (first electrode) formed on one surface of a transparent substrate 3. A semiconductor layer 7 carrying a sensitizing dye is formed on one surface of the transparent electrode 5, and a connection terminal portion 5 a is formed at an outer end of the transparent electrode 5.
[0024]
Further, a counter electrode 15 (second electrode) is present opposite to the semiconductor layer 7 carrying the sensitizing dye. The counter electrode 15 is formed on one surface of the substrate 17. A connecting portion 21 is provided between the counter electrode 15 and the transparent substrate 3, and a connecting terminal portion 21 a provided on the transparent substrate 3 side of the connecting portion 21 is disposed on the transparent substrate 3. The connection terminal portion 21a and the transparent electrode 5 are electrically insulated via the sealing material 11.
[0025]
Further, an electrolyte layer 13 exists between the semiconductor layer 7 and the counter electrode 15. The electrolyte layer 13 is hermetically sealed by the sealing material 11. Note that the photoelectric conversion element 1 receives incident light 19 from the transparent substrate 3.
[0026]
As described above, in the present embodiment, the connection terminal portion 5a of the transparent electrode 5 and the connection terminal portion 21a of the counter electrode 15 exist on the same transparent substrate 3.
[0027]
(Embodiment 2)
FIG. 2 is a schematic cross-sectional view of another embodiment of the photoelectric conversion element of the present invention, in which positive and negative connection terminal portions are arranged on a substrate 17. A connection terminal portion 15a is formed at an outer end of the counter electrode 15, a connection portion 21 is provided between the substrate 17 and the transparent electrode 5, and a connection portion provided on the substrate 17 side of the connection portion 21 is provided. The terminal portion 21a is arranged on the substrate 17. Other than these, the structure is the same as that of the first embodiment.
[0028]
As described above, in the present embodiment, the connection terminal portion 15a of the counter electrode 15 and the connection terminal portion 21a of the transparent electrode 5 exist on the same substrate 17.
[0029]
(Embodiment 3)
FIG. 3 is a schematic sectional view of one embodiment of the photoelectric conversion element module of the present invention, in which a plurality of photoelectric conversion elements of Embodiment 1 are electrically connected.
[0030]
In FIG. 3, in each photoelectric conversion element 1, the connection terminal 5 a of the transparent electrode 5 and the connection terminal 21 a of the counter electrode 15 are electrically connected by connection leads 23. In the present embodiment, since the connection terminal portion 5a of the transparent electrode 5 and the connection terminal portion 21a of the counter electrode 15 are all present on the transparent substrate 3, the connection leads 23 from one direction of the photoelectric conversion element 1 are provided. Can be attached, the workability at the time of modularization is excellent, and the connection strength can be increased. In addition, it is easy to cover the connection lead 23 with a conductive film, and the electrical connection is further ensured.
[0031]
In this embodiment, a plurality of separate substrates are used as the transparent substrate 3 of each photoelectric conversion element 1, but each photoelectric conversion element 1 may be formed on the same continuous substrate.
[0032]
(Embodiment 4)
FIG. 4 is a schematic sectional view of another embodiment of the photoelectric conversion element module of the present invention, in which a plurality of photoelectric conversion elements of Embodiment 2 are electrically connected.
[0033]
4, in each photoelectric conversion element 1, the connection terminal 15a of the counter electrode 15 and the connection terminal 21a of the transparent electrode 5 are electrically connected by connection leads 23. In the present embodiment, since the connection terminal portion 15a of the counter electrode 15 and the connection terminal portion 21a of the transparent electrode 5 are all present on the substrate 17, the connection lead 23 is connected from one direction of the photoelectric conversion element 1. The module can be attached, and the workability at the time of modularization is excellent, and the connection strength can be increased. In addition, it is easy to cover the connection lead 23 with a conductive film, and the electrical connection is further ensured.
[0034]
In this embodiment, a plurality of separate substrates are used as the substrate 17 of each photoelectric conversion element 1, but each photoelectric conversion element 1 may be formed on the same continuous substrate.
[0035]
In the first to fourth embodiments, the transparent substrate 3 is formed of a material having a light transmitting property, and usually, glass or a film is used. The higher the light transmittance of the transparent substrate 3, the better. The preferred light transmittance is 50% or more, more preferably 80% or more.
[0036]
The substrate 17 may be made of metal or the like in addition to the same glass or transparent film as the transparent substrate 3. The substrate 17 may be opaque, but is preferably transparent so that light can be incident from both substrates.
[0037]
Examples of the material of the transparent electrode 5 formed on one surface of the transparent substrate 3 include indium-tin composite oxide (ITO) which is a metal oxide generally used as a transparent electrode, tin oxide doped with fluorine, and the like. Is mentioned.
[0038]
The lower the surface resistance of the transparent electrode 5, the better. A preferred range of the surface resistance is 50 Ω / □ or less, more preferably 30 Ω / □ or less. The lower limit is not particularly limited, but is usually 0.1 Ω / □ or more.
[0039]
The higher the light transmittance of the transparent electrode 5, the better. The preferred light transmittance is 50% or more, more preferably 80% or more. The thickness of the transparent electrode 5 is preferably 0.1 to 10 μm. Within this range, it is easy to form an electrode film having a uniform film thickness, and sufficient light is incident on the semiconductor layer 7 without a decrease in light transmittance. When the transparent electrode 5 is used, it is preferable that light be incident on the transparent electrode 5 side on which the semiconductor layer 7 supporting the sensitizing dye is adhered.
[0040]
When the positive and negative connection terminal portions 5 a and 21 a to the outside are arranged on the transparent substrate 3 (in the first and third embodiments), the transparent electrode 5 is connected to the counter electrode 15. In order to avoid a short circuit with the part 21a, it must be electrically insulated from the connection terminal part 21a. Therefore, the transparent electrode 5 at the portion where the connection terminal portion 21a and the transparent substrate 3 are in contact with each other must be removed by a technique such as etching or insulated by an insulating coating of an organic substance or the like. The etching includes, for example, wet etching, dry etching, electrolytic etching, laser etching, photo etching and the like.
[0041]
The counter electrode 15 functions as a positive electrode of the photoelectric conversion element 1. The counter electrode 15 of the photoelectric conversion element 1 in each of Embodiments 1 to 4 is preferably formed from a material having a catalytic action of giving electrons to a reduced form of the electrolyte in order to efficiently act as a positive electrode of the photoelectric conversion element 1. . Examples of such a material include metals such as platinum, gold, silver, copper, aluminum, rhodium, and indium, or conductive metal oxides such as graphite, indium-tin composite oxide, and fluorine-doped tin oxide. Things. Of these, platinum and graphite are particularly preferred. On the substrate 17 on which the counter electrode 15 is provided, a transparent conductive film (not shown) can be applied on the surface on which the counter electrode 15 is to be applied. This transparent conductive film can be formed, for example, from the same material as the transparent electrode 5 described above. In this case, the counter electrode 15 is also preferably transparent.
[0042]
When the positive and negative connection terminal portions 15a and 21a to the outside are arranged on the substrate 17 (in the case of the second and fourth embodiments), the counter electrode 15 is connected to the transparent electrode 5. In order to avoid a short circuit with the connection terminal 21a, the connection terminal 21a must be electrically insulated. Therefore, the counter electrode 15 at the portion where the connection terminal portion 21a and the substrate 17 are in contact with each other must be removed by a technique such as etching or insulated by an insulating coating of an organic substance or the like. The etching includes, for example, wet etching, dry etching, electrolytic etching, laser etching, photo etching and the like.
[0043]
The semiconductor layer 7 is formed by applying a slurry liquid composed of semiconductor particles to the transparent electrode 5 on the transparent substrate 3 by a coating method using a doctor blade or a bar coater, a spray method, a dip coating method, a screen printing method, a spin coating method, or the like. And then heat-treated at a temperature in the range of 400 to 600 ° C. to form a film. Further, with respect to the film thickness, a desired film thickness can be obtained by repeating the coating and the heat treatment.
[0044]
The thickness of the semiconductor layer 7 is preferably in the range of 0.1 to 100 μm. Within this range, a sufficient photoelectric conversion effect can be obtained, and inconveniences such as remarkable deterioration of light transmittance for visible light and near-infrared light do not occur. The more preferable range of the thickness of the semiconductor layer 7 is 1 to 50 μm, the particularly preferable range is 5 to 30 μm, and the most preferable range is 10 to 20 μm.
[0045]
Examples of the semiconductor material constituting the semiconductor layer 7 include Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, and Si. , Oxides such as Cr, perovskites such as SrTiO ₃ and CaTiO ₃ , or CdS, ZnS, In ₂ S ₃ , PbS, Mo ₂ S, WS ₂ , Sb ₂ S ₃ , Bi ₂ S ₃ , ZnCdS ₂ , Cu sulfides such as _{2 S, CdSe, in 2 Se} 3, WSe 2, HgS, PbSe, metal chalcogenides such as CdTe, other _{GaAs, Si, Se, Cd 2} P 3, Zn 2 P 3, InP, AgBr, PbI 2 , HgI ₂ , BiI _{3 and the} like. Further, a composite containing at least one selected from the above-mentioned semiconductor materials, for example, CdS / TiO ₂ , CdS / AgI, Ag ₂ S / AgI, CdS / ZnO, CdS / HgS, CdS / PbS, ZnO / ZnS, ZnO _{/ ZnSe, CdS / HgS, CdS} x / CdSe 1-x, CdS x / Te 1-x, CdSe x / Te 1-x, ZnS / CdSe, ZnSe / CdSe, CdS / ZnS, TiO 2 / Cd 3 P 2 _{, CdS / CdSeCd y Zn 1-} y S, is CdS / HgS / CdS preferred.
[0046]
Generally, the particle size of the semiconductor particles is preferably in the range of 5 to 1000 nm. Within this range, the pore diameter of the semiconductor layer 7 becomes small, so that the reduction of the photocurrent due to the difficulty in moving the oxidation-reduction substance in the electrolyte solution does not occur. Can be increased, so that a sufficient amount of sensitizing dye can be obtained, and as a result, a large photocurrent can be obtained. A particularly preferred range of the particle size of the semiconductor particles is 10 to 100 nm.
[0047]
By controlling the thickness of the semiconductor layer 7 or the particle size of the semiconductor particles, the roughness factor (the ratio of the actual area inside the semiconductor layer to the substrate area) of the semiconductor layer 7 can be determined. The roughness factor is preferably 20 or more, and more preferably 150 or more. Within this range, the amount of the sensitizing dye carried is sufficient, and the photoelectric conversion characteristics can be improved. The upper limit of the roughness factor is generally about 5000. The roughness factor increases as the thickness of the semiconductor layer 7 increases, the surface area of the semiconductor layer 7 increases, and an increase in the carrying amount of the sensitizing dye can be expected. However, when the film thickness is too large, the effects of the light transmittance and the resistance loss of the semiconductor layer 7 begin to appear.
[0048]
Further, a surfactant, polyethylene glycol, a cellulosic material, or the like is added to the semiconductor layer 7 and burned during the heat treatment of the semiconductor layer 7 to make the semiconductor layer 7 porous or change the particle size of the semiconductor particles. By increasing the porosity of the film, the roughness factor can be increased without increasing the film thickness. However, if the porosity is too high, the contact area between the semiconductor particles decreases, and the effect of resistance loss must be considered. For this reason, the porosity of the semiconductor layer 7 is preferably 50% or more, and the upper limit is generally about 80%. The porosity of the film can be calculated from the measurement result of the adsorption-desorption isotherm of nitrogen gas or krypton gas at the temperature of liquid nitrogen.
[0049]
As the sensitizing dye, any dye commonly used in conventional dye-sensitized photoelectric conversion elements can be used. Such dyes, for _{example, RuL 2 (H 2 O)} 2 type ruthenium - cis - diaqua - bipyridyl complexes or ruthenium - tris _(RuL 3), ruthenium - bis _(RuL 2), osmium - tris _(OsL 3) , osmium - bis (OsL ₂₎ type transition metal complexes, or zinc - tetra (4-carboxyphenyl) porphyrin, iron - Hekisashianido complex, phthalocyanine, and the like. As organic dyes, 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, cyanine dyes, merocyanine dyes Dyes, xanthene-based dyes, and the like. Among them, a ruthenium-bis (RuL ₂ ) derivative is particularly preferable because it has a broad absorption spectrum in a visible light region.
[0050]
As a method of supporting the sensitizing dye on the semiconductor layer 7, for example, a method of immersing the transparent substrate 3 provided with the transparent electrode 5 with the semiconductor layer 7 applied thereon in a solution in which the sensitizing dye is dissolved can be mentioned. . As a solvent for this solution, any solvent can be used as long as it can dissolve the sensitizing dye, such as water, alcohol, toluene and dimethylformamide. In addition, it is effective to heat and reflux or apply ultrasonic waves when the transparent substrate 3 is immersed in the sensitizing dye solution for a certain period of time as an immersion method. After the dye is supported on the semiconductor layer 7, the sensitizing dye remaining on the semiconductor layer 7 without being supported may be washed with alcohol or heated under reflux. Further, in order to coat the surface of the semiconductor particles on which the sensitizing dye is not supported, it is preferable that t-butylpyridine is dissolved in alcohol. When t-butylpyridine is present in the alcohol, at the interface between the semiconductor particles and the electrolyte, the surface of the semiconductor particles and the electrolyte can be separated by the sensitizing dye and t-butylpyridine, thereby suppressing leakage current. Therefore, the characteristics of the photoelectric conversion element can be significantly improved.
[0051]
The amount of the sensitizing dye carried on the semiconductor particles may be in the range of 10 ⁻⁸ to 10 ⁻⁶ mol / cm ² , and particularly 0.1 × 10 ^{−7 to} 9.0 × 10 ⁻⁷ mol / cm 2. ² is preferred. Within this range, the effect of economically and sufficiently improving the photoelectric conversion efficiency can be obtained.
[0052]
As the electrolyte used in the electrolyte layer 13 in the photoelectric conversion elements 1 of Embodiments 1 to 4, as long as a pair of oxidation-reduction-based constituent substances composed of an oxidant and a reductant is contained in a solvent, the type thereof is particularly preferable. Although not limited, it is preferable that the oxidized form and the reduced form are oxidation-reduction constituent materials having the same charge. The term “redox-based constituent substance” in this specification means a pair of substances that are reversibly present in the form of an oxidized form and a reduced form in an oxidation-reduction reaction. Examples of the oxidation-reduction-based constituent materials that can be used in the present embodiment include chlorine compound-chlorine, iodine compound-iodine, bromine compound-bromine, thallium ion (III) -thallium ion (I), mercury ion (II) -mercury ion (I), ruthenium ion (III) -ruthenium ion (II), copper ion (II) -copper ion (I), iron ion (III) -iron ion (II), vanadium ion (III) -vanadium ion (II) ), Manganate ion-permanganate ion, ferricyanide-ferrocyanide, quinone-hydroquinone, fumaric acid-succinic acid, and the like. Among them, an iodine compound-iodine is preferable, and examples of the iodine compound include metal iodides such as lithium iodide and potassium iodide, quaternary ammonium salt compounds such as tetraalkylammonium iodide and pyridinium iodide, and dimethylpropylimidazo iodide. Particularly preferred are imidazolium iodide compounds such as lithium.
[0053]
The solvent used for dissolving the electrolyte is preferably a compound that dissolves the oxidation-reduction constituent material and has excellent ion conductivity. As the solvent, any of an aqueous solvent and an organic solvent can be used, but an organic solvent is preferable in order to further stabilize the oxidation-reduction-type constituent material. For example, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, carbonate compounds such as propylene carbonate, methyl acetate, methyl propionate, ester compounds such as γ-butyrolactone, diethyl ether, 1,2-dimethoxyethane, 1,3 -Dioxosilane, tetrahydrofuran, ether compounds such as 2-methyl-tetrahydrafuran, heterocyclic compounds such as 3-methyl-2-oxazodirinone and 2-methylpyrrolidone, nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile, sulfolane, Aprotic polar compounds such as didimethylsulfoxide and dimethylformamide; Each of these can be used alone, or two or more of them can be used in combination. Among them, carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazodilinone and 2-methylpyrrolidone, and nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile are particularly preferable.
[0054]
Note that a solar cell array is formed by electrically connecting the conventional photoelectric conversion element shown in FIG. 5 and the photoelectric conversion elements of the first and second embodiments of the present invention shown in FIGS. 1 and 2. Is also possible.
[0055]
【Example】
Next, the present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.
[0056]
(Example 1)
Asahi Glass conductive glass “F-SnO ₂ ” (trade name, glass substrate with a transparent conductive film coated with fluorine-doped SnO ₂ on the surface to give conductivity, cut into 12 mm in length and 12 mm in width, Except for one piece (length 12 mm, width 1.5 mm) having a surface resistance of 10 Ω / □ and a thickness of 1 mm, masking was performed with a masking tape. Thereafter, the unmasked transparent conductive film was removed by etching with a zinc oxide powder and a 10% by mass aqueous hydrochloric acid solution.
[0057]
Next, in a mixed solution of water and acetylacetone containing a surfactant (mixing volume ratio = 20/1), titanium oxide particles “P25” (trade name, average particle diameter: 20 nm) manufactured by Nippon Aerosil Co., Ltd. are concentrated at a concentration of about 38. A slurry liquid was prepared by dispersing so as to be a mass%. Next, this slurry liquid was applied to the center of the above-mentioned conductive glass and dried, and the obtained dried product was heated in air at 500 ° C. for 30 minutes to form a 10 μm-thick titanium oxide film on the substrate. The size of the obtained titanium oxide film was 8 mm in length and 8 mm in width. Next, the conductive glass provided with the titanium oxide film is immersed in a sensitizing dye solution represented by Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ , Dye-carrying treatment was carried out while refluxing at ℃ to obtain a semiconductor electrode.
[0058]
The vertical 10 mm, platinum was deposited to a thickness of 20nm on the conductive glass "F-SnO _2" cut out laterally 10 mm, to obtain a opened counterelectrode small hole for injection of the central portion electrolyte.
[0059]
The semiconductor electrode and the counter electrode thus obtained are aligned with their centers aligned, a polyethylene spacer film (40 μm thick) is sandwiched between them, and they are heated and pressed at 120 ° C., and then the semiconductor electrode and the counter electrode are placed. The photoelectric conversion element was formed by injecting an electrolyte solution by utilizing the capillary phenomenon between them. As the electrolyte solution, a mixed solution of ethylene carbonate containing 0.5 mol / dm ³ of tetrapropylammonium iodide, 0.04 mol / dm ³ of iodine and acetonitrile (mixing volume ratio = 80/20) was used.
[0060]
The injection hole is sealed with a polyethylene film, and a Ni film (length 12 mm, width 1.5 mm, thickness 35 μm) is interposed between the counter electrode and the portion where the conductive film does not exist due to the etching of the semiconductor electrode. The connection portion was covered with the paste to obtain a photoelectric conversion element having the same structure as that of the first embodiment.
[0061]
The thus obtained photoelectric conversion element was irradiated with pseudo sunlight (100 mW / cm ² , AM1.5) by a solar simulator, and the photocurrent-voltage characteristics were measured. As a result, characteristics of an open-end voltage of 688 mV, a short-circuit current density of 7.88 mA / cm ² , and a shape factor of 0.58 were obtained.
[0062]
(Example 2)
The conductive glass was not subjected to the etching treatment, and the portion subjected to the etching treatment in Example 1 was insulated and coated with a polyimide tape (30 μm) instead of the etching treatment, and then a photoelectric conversion element was produced in the same manner as in Example 1.
[0063]
The photocurrent-voltage characteristics were measured in the same manner as in Example 1. As a result, the open-circuit voltage was 692 mV, the short-circuit current density was 7.25 mA / cm ² , and the shape factor was 0.53.
[0064]
【The invention's effect】
As described above, the present invention provides a photoelectric conversion element capable of easily manufacturing a solar cell module and a solar cell array by arranging connection terminals to the outside on the same plane, and a photoelectric conversion using the same. An element module can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing one embodiment of a photoelectric conversion element of the present invention.
FIG. 2 is a schematic sectional view showing another embodiment of the photoelectric conversion element of the present invention.
FIG. 3 is a schematic sectional view showing one embodiment of a photoelectric conversion element module of the present invention.
FIG. 4 is a schematic sectional view showing another embodiment of the photoelectric conversion element module of the present invention.
FIG. 5 is a schematic sectional view of a conventional photoelectric conversion element.
FIG. 6 is a schematic sectional view of a conventional photoelectric conversion element module.
[Explanation of symbols]
Reference Signs List 1 photoelectric conversion element 3 transparent substrate 5 transparent electrode (first electrode)
5a connection terminal portion 7 semiconductor layer 11 sealing material 13 electrolyte layer 15 counter electrode (second electrode)
15a connection terminal 17 substrate 19 incident light 21 connection 21a connection terminal 23 connection lead

Claims (5)

A first electrode having a semiconductor layer carrying a sensitizing dye thereon, a second electrode facing the semiconductor layer of the first electrode, a semiconductor layer of the first electrode, and the second electrode; And an electrolyte layer disposed between the photoelectric conversion element and
The first electrode and the second electrode each include a connection terminal portion,
The connection terminal portion of the first electrode and the connection terminal portion of the second electrode are arranged on the same plane. The photoelectric conversion element according to claim 1, wherein the first electrode and the second electrode are formed on a substrate, respectively. A photoelectric conversion element module in which a plurality of photoelectric conversion elements according to claim 1 or 2 are electrically connected,
A photoelectric conversion element module, wherein a connection terminal of a first electrode of the photoelectric conversion element and a connection terminal of a second electrode of another photoelectric conversion element adjacent thereto are electrically connected to each other. . The photoelectric conversion element module according to claim 3, wherein the connection terminal portion of the first electrode and the connection terminal portion of the second electrode are electrically connected via a metal conductor. The photoelectric conversion element module according to claim 4, wherein the metal conductor is covered with a conductive film.

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