JP4799853B2 - Electrode for photoelectric conversion element, photoelectric conversion element, and dye-sensitized solar cell - Google Patents

Description

The present invention relates to a photoelectric conversion element electrode, a photoelectric conversion element, and a dye-sensitized solar cell.

Dye-sensitized solar cells are a type of photoelectric conversion element developed by Gretzell et al. In Switzerland, and have advantages such as high conversion efficiency and low manufacturing cost, and are attracting attention as a new type of solar cell ( For example, see Patent Literature 1 and Non-Patent Literature 1).
The schematic configuration of the dye-sensitized solar cell is as follows: a working electrode having a porous film made of oxide semiconductor fine particles (for example, nanoparticles such as titanium dioxide) on a transparent conductive substrate, and facing the working electrode. The porous membrane carries a sensitizing dye, and an electrolyte containing a redox pair (for example, I ₂ / I ₃ ⁻ ) is filled between the working electrode and the counter electrode. It is a thing.
In this type of dye-sensitized solar cell, the oxide semiconductor fine particles are sensitized by a sensitizing dye that absorbs incident light such as sunlight, and an electromotive force is generated between the working electrode and the counter electrode. It functions as a photoelectric conversion element that converts power.
As a material for the counter electrode, a material that allows the oxidation-reduction reaction of the oxidation-reduction pair to proceed smoothly on the surface of the electrode is desirable, and platinum is preferable. Conventionally, as a counter electrode of a dye-sensitized solar cell, conductive glass in which a conductive layer such as a platinum layer is formed on the surface of glass is frequently used. As a method for forming the platinum layer, a vacuum film-forming method such as sputtering or vapor deposition, or a platinum-containing solution such as a chloroplatinate solution is applied to the substrate surface, followed by heat treatment (for example, 200 ° C. or more) to release platinum. A wet film forming method is used.
Japanese Patent No. 2664194 M. Graetzel et al., Nature (UK), 1991, No. 737, p. 353

  However, an electrode obtained by using a vacuum film forming method is unsatisfactory in terms of productivity, equipment costs, and the like. There is also a problem that it is difficult to obtain a platinum layer having a large effective area of the platinum layer as compared with the porous film of the working electrode disposed oppositely. When the wet film forming method is used, since heat treatment is performed, there is a problem that application to a plastic substrate is difficult.

This invention is made | formed in view of the said situation, and makes it a subject to provide the electrode for photoelectric conversion elements which can be manufactured at low cost, and can enlarge an effective area easily, and a photoelectric conversion element. .

In order to solve the above-mentioned problems, the present invention is such that a conductive layer comprising platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and the conductive layer is interposed between the platinum particles. Provided is an electrode for a photoelectric conversion element, wherein a gap communicating with a surface is formed.
In the electrode for a photoelectric conversion element of the present invention, the platinum particles preferably contain nanoparticulate platinum particles as a main component.
In the electrode for a photoelectric conversion element of the present invention, the conductive binder preferably contains a conductive polymer as a main component.
Examples of the conductive polymer include poly (3,4-ethylenedioxythiophene) and derivatives thereof.
According to the present invention, a conductive layer comprising platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and the gap between the platinum particles communicates with the surface of the conductive layer. There is provided a photoelectric conversion element comprising an electrode formed of
According to the present invention, a conductive layer comprising platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and the gap between the platinum particles communicates with the surface of the conductive layer. Provided is a dye-sensitized solar cell comprising an electrode in which is formed.

According to the electrode for a photoelectric conversion element of the present invention, an electrode having stable characteristics can be easily produced at low cost. Since the conductive layer can be formed without using high-temperature heat treatment, problems such as deterioration of the base material can be avoided even when the base material is inferior in heat resistance, such as plastic. Furthermore, by binding the platinum particles with a conductive binder, the electrode surface has a porous structure with voids, and a large effective area (surface area) can be secured on the electrode surface.
According to the photoelectric conversion element of the present invention, since a large effective area (surface area) is ensured on the electrode surface, good photoelectric conversion efficiency can be obtained.
According to the dye-sensitized solar cell of the present invention, since incident light is sensitized with a sensitizing dye, light energy can be easily converted into electric power, and the electrode itself has a large effective area (surface area). Therefore, good photoelectric conversion efficiency can be obtained.

The present invention will be described below based on the best mode.
Fig.1 (a) is sectional drawing which shows the example of 1 form of the electrode of this invention. For example, the electrode 1 (also referred to as an electrode substrate) is provided with a conductive layer 3 including platinum particles and a conductive binder that binds the platinum particles on a substrate 2.

Although it does not specifically limit as the board | substrate 2, The sheet | seat, plate, etc. which consist of glass, a plastics, a metal, a ceramic, etc. can be used.
Examples of the glass that can be used as the substrate 2 include borosilicate glass, quartz glass, soda glass, and phosphate glass. Examples of the plastic that can be used as the substrate 2 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polyimide. Examples of the metal that can be used as the substrate 2 include titanium and nickel.
The substrate 2 is formed by forming a second conductive layer (not shown) made of a conductive metal oxide such as ITO, FTO, FTO / ITO, or a metal on the surface on which the conductive layer 3 is provided. There may be. The material constituting the substrate and the second conductive layer is preferably a material that is not easily damaged even when the electrolyte contacts it. When an electrolyte containing iodine is used, for example, copper or silver is not preferable because it is attacked by iodine and easily dissolved.

The conductive layer 3 includes platinum particles and a conductive binder that binds the platinum particles, and voids communicating with the surface 3a of the conductive layer 3 are formed between the platinum particles.
Although it does not specifically limit as platinum particle, From the points, such as film forming property and a surface area, a nanoparticulate form is preferable and the thing excellent in electroconductivity is preferable. In the present invention, “nanoparticulate” refers to a particle having a main particle size of 1000 nm or less. Fibrous particles having a length exceeding 1000 nm in the longitudinal direction, spike-like particles having protrusions having a length exceeding 1000 nm on the surface of the particle, and the like can also be referred to as nanoparticle-like in the present invention. Also,
As the shape of the platinum particles, one kind is suitably selected from spherical particles, polygonal particles, fibrous particles, dendritic particles, spike-like particles, flake-like particles, porous particles, etc., or a plurality of types are combined. Can be used. In particular, dendritic particles, spike-like particles, porous particles and the like having a large surface area are suitable.

In the conductive layer 3 of the electrode 1 of the present invention, platinum particles are bound by a conductive binder in order to form a film of platinum particles on the substrate 2. As the conductive binder, those which do not require high temperature and can easily form a coating film are preferable. From this viewpoint, a conductive polymer is preferable. Examples of the conductive polymer include polythiophene, polyaniline, polypyrrole, and derivatives thereof. A kind of conductive polymer may be used, and a composite of a plurality of kinds of conductive polymers may be used as the conductive binder.
As polythiophene and derivatives thereof, those in which the hydrogen atom of the thiophene ring is unsubstituted, or those having one or more substitutions such as an alkyl group, a halogen atom, an alkoxy group, and a cyano group can be used. -Alkylthiophene), poly (3,4-dialkylthiophene), poly (3,4-ethylenedioxythiophene) (abbreviation PEDOT) and the like are exemplified.
As polypyrrole and derivatives thereof, those in which the hydrogen atom of the pyrrole ring is unsubstituted, or those having one or more substitutions such as an alkyl group, a halogen atom, an alkoxy group, and a cyano group can be used. -Alkylpyrrole), poly (3,4-dialkylpyrrole), poly (3,4-alkylenedioxypyrrole) and the like.
Examples of polyaniline and derivatives thereof include polyaniline, poly (N-alkylaniline), poly (arylamine), poly (phenylenediamine), poly (aminopyrene) and the like.

When the conductive layer 3 formed by binding platinum particles with a conductive binder is formed on the substrate 2, voids formed as portions where the conductive binder is not filled between the platinum particles are formed. Here, the void is a cavity communicating with the surface 3a of the conductive layer 3, and a path for the electrolyte (electrolyte etc.) to enter is formed in the void. Therefore, in the electrode of this embodiment, the electrolyte penetrates into the gap, and the entire inner surface of the gap can function as an effective area that contributes to charge transfer, reaction, and the like.
In particular, it is preferable to use nanoparticles having a large apparent volume per weight because the voids are easily formed effectively.
Furthermore, since a film of platinum particles is formed using a conductive binder, the conductive layer 3 can be formed without using a high-temperature heat treatment, and can be easily applied to a substrate having poor heat resistance such as plastic. is there.

  When nanoparticles having a large apparent volume per weight are used, a relatively large amount of binder is required to improve the film forming property and film strength. For this reason, when an insulating resin such as polyester, polyurethane, polyvinylidene fluoride (PVdF), or polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP) is used as a binder, contact between particles is prevented by the binder. Since the conductivity of the electrode 1 may be impaired, it is difficult to control the amount of binder added and the mixed state. On the other hand, in the case where the binder has conductivity, it is not necessary to increase the internal resistance by suppressing the decrease in conductivity due to the binder interposed between the particles, and there are also restrictions on the composition of the conductive layer 3 and the mixing method. There is an advantage of being small.

  The compounding ratio of the platinum particles and the conductive binder is appropriately set according to the type of platinum particles and conductive binder used. If there are too many platinum particles compared to the conductive binder, the platinum particles are not bound and there is a possibility that the film cannot be formed. Also, if the amount of platinum particles is too small compared to the conductive binder, the platinum particles are buried in the conductive binder and the voids may not be formed. And a conductive binder.

The method for producing the electrode 1 of the present invention is not particularly limited. For example, platinum particles and a conductive binder are dispersed or dissolved in a solvent, and the obtained mixture is applied onto the substrate 2 and dried. Thus, the conductive layer 3 can be formed.
Examples of the solvent include, but are not limited to, tetrahydrofuran, methyl ethyl ketone, dimethylformamide, acetonitrile, methoxyacetonitrile, propionitrile, propylene carbonate, diethyl carbonate, methanol, γ-butyrolactone, N-methylpyrrolidone, and the like. .
It is desirable that the platinum particles and the conductive binder are dispersed or dissolved as uniformly as possible in the solvent, and it is preferable to consider the dispersibility and solubility of the platinum particles and the conductive binder in selecting the solvent. The conductive binder is desirably sufficiently soluble or dispersible in the solvent.

The application method of the mixture is not particularly limited, and various application methods such as doctor blade, spin coating, dipping, and printing methods can be applied.
It is also possible to repeat the application and drying of the mixture a plurality of times to laminate two or more conductive layers 3. In the case of the present invention, by laminating the conductive layer 3 to increase the film thickness, voids can communicate between the layers, so that the effective area can be increased.
On the other hand, for example, when a platinum layer is formed using a vacuum film forming method, only the surface of the outermost layer is effective as an effective area even if a plurality of layers are stacked, and the effect of expanding the effective area is obtained. I can't.

  According to the electrode of this embodiment, it is possible to easily manufacture an electrode with stable characteristics at a low cost. Further, by binding the platinum particles with a conductive binder, the surface 3a of the conductive layer 3 has a porous structure having voids, and a large effective area (surface area) of the electrode 1 can be secured. In addition, since the conductive layer 3 can be formed without using high-temperature heat treatment, even if a base material having poor heat resistance such as plastic is used as the substrate 2, problems such as deterioration of the base material can be prevented. Can do. By using a plastic substrate as the substrate 2, it becomes possible to produce a lightweight electrode or a flexible electrode, and various applications are possible.

  Next, an embodiment of the photoelectric conversion element of the present invention will be described with reference to FIG. A photoelectric conversion element 10 illustrated in FIG. 1B is a dye-sensitized solar cell including the electrode 1 illustrated in FIG. 1A as a counter electrode. The dye-sensitized solar cell 10 includes a working electrode 8 having an oxide semiconductor porous film 7 made of oxide semiconductor fine particles on a transparent electrode substrate 6, and a counter electrode 1 provided to face the working electrode 8. The oxide semiconductor porous film 7 carries a sensitizing dye, and an electrolyte layer 9 containing a redox pair is provided between the working electrode 8 and the counter electrode 1. Yes.

The transparent electrode substrate 6 used for the working electrode 8 is obtained by forming a conductive layer 5 made of a conductive material on a transparent base material 4 made of a glass plate, a plastic sheet or the like. Thereby, it can function as a window into which light is introduced from the outside.
As the material of the transparent substrate 4, a material having high light transmittance is preferable for use. In addition to glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), etc. A transparent plastic sheet, a ceramic polishing plate such as titanium oxide or alumina can be used.

From the viewpoint of the light transmittance of the transparent electrode substrate 6, the conductive layer 5 of the working electrode 8 is an oxide having excellent transparency, such as tin-doped indium oxide (ITO), tin oxide (SnO ₂ ), or fluorine-doped tin oxide (FTO). It is preferable to use a physical semiconductor alone or in combination of a plurality of types. However, the present invention is not particularly limited thereto, and an appropriate material suitable for the intended purpose may be selected and used from the viewpoints of light transmittance and conductivity. In addition, in order to improve the current collection efficiency from the oxide semiconductor porous membrane 7 and the electrolyte layer 9, the area ratio of gold, silver, platinum, aluminum, nickel, and the like is within a range that does not significantly impair the light transmittance of the transparent electrode substrate 6. A metal wiring layer made of titanium or the like may be used in combination with the transparent conductive layer. In the case of using a metal wiring layer, it is preferable that light is transmitted as uniformly as possible through the transparent electrode substrate 6 as a pattern such as a lattice shape, a stripe shape, or a comb shape.
As a method for forming the conductive layer 5 on the transparent substrate 4, a known appropriate method corresponding to the material of the conductive layer 5 may be used. For example, the conductive layer 5 is formed from an oxide semiconductor such as ITO. In this case, thin film forming methods such as sputtering, CVD, SPD (spray pyrolysis deposition), and vapor deposition can be used.

The oxide semiconductor porous film 7 includes one or _{two of} titanium dioxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), niobium oxide (Nb ₂ O ₅ ), and the like. It is a porous thin film mainly composed of oxide semiconductor fine particles having an average particle diameter of 1 to 1000 nm, in which more than one species are combined.
As a method for forming the oxide semiconductor porous film 7, for example, a dispersion in which commercially available oxide semiconductor fine particles are dispersed in a desired dispersion medium or a colloidal solution that can be prepared by a sol-gel method is used as necessary. After adding a desired additive, the transparent electrode substrate 6 is applied in a colloidal solution in addition to coating by a known application such as a screen printing method, an ink jet printing method, a roll coating method, a doctor blade method, a spin coating method, or a spray coating method. Electrophoretic electrodeposition method in which oxide semiconductor fine particles are adhered to the transparent electrode substrate 6 by immersion and electrophoretic electrophoresis, a method in which a foaming agent is mixed and applied to a colloidal solution or dispersion, and then sintered and made porous. After polymer microbeads are mixed and applied, the polymer microbeads are removed by heat treatment or chemical treatment to form voids and make them porous. It can be applied to a method.

  The sensitizing dye supported on the oxide semiconductor porous film 7 is not particularly limited. For example, a ruthenium complex, an iron complex, a porphyrin-based, or a phthalocyanine-based including a bipyridine structure, a terpyridine structure, or the like as a ligand. From metal complexes, organic dyes such as eosin, rhodamine, merocyanine, etc., they can be appropriately selected and used according to the application and the material of the oxide semiconductor porous film 7.

As the electrolyte composition constituting the electrolyte layer 9, an electrolyte such as an organic solvent containing an oxidation-reduction pair or an ionic liquid (room temperature molten salt) can be used. In addition, by adding an appropriate gelling agent or filler to these electrolytic solutions, a so-called gel electrolyte that is quasi-solidified while suppressing fluidity can also be used. In addition, a solid polymer electrolyte having an electric transport ability can be used.
Examples of the organic solvent include acetonitrile, methoxyacetonitrile, propionitrile, propylene carbonate, diethyl carbonate, and γ-butyrolactone.
Examples of the ionic liquid include salts comprising a cation such as a quaternized imidazolium cation or a quaternized pyridinium cation and an anion such as an iodide ion, a bistrifluoromethanesulfonylimide anion, or a dicyanoamide anion. .

As the gel electrolyte, for example, as described in Japanese Patent Application No. 2003-347193 filed by the present applicant, an electrolyte composition containing an ionic liquid and metal oxide particles and / or conductive particles is used. You can also.
In the gel electrolyte, the metal oxide particles include TiO ₂ , SnO ₂ , WO ₃ , ZnO, ITO, BaTiO ₃ , Nb ₂ O ₅ , In ₂ O ₃ , ZrO ₂ , Ta ₂ O ₅ , La ₂ O. ₃ , SrTiO ₃ , Y ₂ O ₃ , Ho ₂ O ₃ , Bi ₂ O ₃ , CeO ₂ , Al ₂ O _3, or one or a mixture of two or more. The metal oxide may be an impurity doped or a composite oxide. Examples of the conductive particles include those composed mainly of carbon, and specific examples include carbon-based particles such as carbon nanotubes, carbon fibers, carbon black, and carbon nanohorns.

The redox pair contained in the electrolyte layer 9 is not particularly limited and can be obtained by adding a pair of iodine / iodide ions, bromine / bromide ions and the like. As a supply source of iodide ion or bromide ion, the lithium salt of the halide, quaternized imidazolium salt, tetrabutylammonium salt and the like can be used alone or in combination.
Additives such as lithium salt and tert-butylpyridine can be added to the electrolyte composition as necessary.

  A method for forming the electrolyte layer 9 made of the electrolyte composition between the working electrode 8 and the counter electrode 1 is not particularly limited. For example, after the working electrode 8 and the counter electrode 1 are disposed to face each other, A method in which an electrolyte is filled between both electrodes 1 and 8 to form an electrolyte layer 9, an electrolyte layer 9 is formed on the working electrode 8 or the counter electrode 1 by dropping or coating the electrolyte layer 9, and then on the electrolyte layer 9. A method of overlapping the other electrode can be used. In order to prevent the electrolyte from leaking between the working electrode 8 and the counter electrode 1, the gap between the working electrode 8 and the counter electrode 1 is sealed with a film as necessary, or the working electrode 8 and the electrolyte are sealed. It is also preferable to store the layer 9 and the counter electrode 1 in a suitable case.

  In the conventional dye-sensitized solar cell, the surface area of the working electrode is increased by the oxide semiconductor porous layer, but the effective surface area is small because the surface of the counter electrode is formed by a sputtered layer or the like. On the other hand, according to the photoelectric conversion element 10 of this embodiment, a large effective area (surface area) is ensured on the electrode surface by including the above-described electrode. Therefore, the photoelectric conversion element 10 of the present embodiment can realize a photoelectric conversion efficiency comparable to or higher than that using a sputter-formed platinum film as an electrode.

<Production of Example Electrode>
According to the formulation shown in Table 1, platinum particles and a conductive binder are dissolved and dispersed in a solvent, and the obtained liquid material is applied onto a substrate with a doctor blade, and then dried sufficiently, whereby an electrode serving as a counter electrode is obtained. Obtained.
As the substrate, a commercially available glass with an FTO film or a PET film with an ITO film was used. As the conductive binder, soluble polypyrrole or poly (3,4-ethylenedioxythiophene) was used. In Table 1, PEDOT represents poly (3,4-ethylenedioxythiophene).

<Manufacture of Electrode of Comparative Example 1>
A platinum layer-formed glass was produced by sputtering a platinum layer having a thickness of 1000 mm (= 100 nm) on a glass with an FTO film, and this was used as an electrode. In this example, a conductive layer made of platinum particles and a binder is not used.

<Manufacture of electrode of Comparative Example 2>
As shown in Table 1, platinum particles were dispersed in a solvent, and the resulting mixture was applied onto a substrate with a doctor blade and then sufficiently dried to obtain an electrode serving as a counter electrode. A commercially available glass with an FTO film was used as the substrate.

<Manufacture of Electrode of Comparative Example 3>
According to the formulation shown in Table 1, platinum particles and an insulating binder are dissolved and dispersed in a solvent, and the obtained liquid material is applied onto a substrate with a doctor blade, and then dried sufficiently, whereby an electrode serving as a counter electrode is obtained. Obtained. A commercially available glass with an FTO film was used as the substrate.
In Table 1, PVdF-HFP represents a polyvinylidene fluoride-hexafluoropropylene copolymer.

<Method for evaluating electrode film strength>
Regarding the electrodes according to Examples or Comparative Examples, the presence or absence of peeling of the conductive layer was visually determined, and the case where there was no peeling of the conductive layer was judged as ◯, the case where there was slight peeling as △, and the case where peeling was significant as x. Evaluated by criteria.

<Observation of electrode surface>
When the surfaces of the electrode of Example and the electrode of Comparative Example 3 were observed using FE-SEM, platinum particles were bound by a binder polymer, and many voids extending in the depth direction from the surface of the conductive layer were formed. It was confirmed that the platinum particles were exposed over a wide area. In the binding part of the binder polymer, the platinum particles were covered with the binder polymer.
Since the binder polymer (PEDOT) also has conductivity in the electrode of the example, both the portion where the platinum particles are exposed and the portion covered with the binder polymer contribute to charge transfer and reaction. It is considered that it can function as an effective area.
On the other hand, in the electrode of Comparative Example 3, since the binder polymer (PVdF-HFP) is insulative, the portion covered with the binder polymer does not contribute to charge transfer or reaction, and the effective area of the electrode surface is small. it is conceivable that.

<Preparation of dye-sensitized solar cell>
A dye-sensitized solar cell using the electrode according to the example or the comparative example as a counter electrode was produced by the following procedure.
In the dye-sensitized solar cell 10 as shown in FIG. 1, titanium oxide nanoparticles having an average particle diameter of 13 to 20 nm are contained on the surface of the FTO film (conductive layer 5) side of the glass substrate with an FTO film serving as the transparent electrode substrate 6. The slurry to be applied was applied and dried, followed by baking at 450 ° C. for 1 hour, whereby an oxide semiconductor porous film 7 was formed. Further, the transparent electrode substrate 6 provided with the oxide semiconductor porous film 7 was immersed in the dye solution overnight so that the dye was supported on the oxide semiconductor porous film 7 to produce a working electrode. A ruthenium bipyridine complex (N3 dye) was used as the dye.
As the electrolytic solution, an electrolytic solution based on an ionic liquid was used as described below. 1-hexyl-3-methylimidazolium-iodide (HMIm-I) was used as the ionic liquid, and an appropriate amount of lithium iodide, iodine, and 4-tert-butylpyridine were added to the electrolyte solution. Prepared.
The working electrode 8 was superposed on the counter electrode 1, and the electrolyte solution was filled between both electrodes to prepare a dye-sensitized solar cell 10 serving as a test cell.

<Method for measuring photoelectric conversion efficiency of dye-sensitized solar cell>
The photoelectric conversion efficiency was measured using light irradiation conditions with an air mass (AM) of 1.5 and an irradiance of 100 mW / cm 2.

<Test results>
Table 1 shows the evaluation results of the film strength of the electrodes and the measurement results of the photoelectric conversion efficiency of the dye-sensitized solar cells.

The electrodes according to each example exhibited excellent characteristics that are comparable or superior to those of platinum layer-formed glass. Further, as can be seen from Example 5, the present invention can provide good electrodes and dye-sensitized solar cells even when applied to a plastic substrate.
On the other hand, as shown in Comparative Example 3, when the platinum particles are bound using PVdF-HFP, which is an insulating binder, the electrical bonding between the platinum particles is hindered by the insulating resin, so that the conductivity of the electrodes is reduced. As a result, the photoelectric conversion efficiency deteriorated.
As shown in Comparative Example 2, when the platinum particles were dispersed in a solvent without using a binder and applied to a substrate to form a film, the platinum particles were not fixed on the substrate after drying, and the film was easily peeled off. Oops. For this reason, in Comparative Example 2, a dye-sensitized solar cell could not be produced.
As described above, since the electrode of the present invention has both a large electrode surface area and high conductivity, it has been found that when applied to the counter electrode of a dye-sensitized solar cell, good photoelectric conversion characteristics are exhibited.

  The electrode of the present invention can be preferably used as an electrode for a photoelectric conversion element such as a dye-sensitized solar cell. In addition, it is expected to be useful as an electrode for various elements having an electrical or electrochemical action.

(A) It is sectional drawing which shows the example of 1 form of the electrode of this invention. (B) It is sectional drawing which shows one example of a photoelectric conversion element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrode, 2 ... Board | substrate, 3 ... Conductive layer, 3a ... The surface of a conductive layer, 10 ... Photoelectric conversion element (dye-sensitized solar cell).

Claims (6)

A conductive layer including platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and a void communicating with the surface of the conductive layer is formed between the platinum particles. An electrode for a photoelectric conversion element . The electrode for a photoelectric conversion element according to claim 1, wherein the platinum particle contains nanoparticle-like platinum particles as a main component. The electrode for a photoelectric conversion element according to claim 1, wherein the conductive binder contains a conductive polymer as a main component. The electrode for a photoelectric conversion element according to claim 3, wherein the conductive polymer is poly (3,4-ethylenedioxythiophene) or a derivative thereof.   An electrode in which a conductive layer including platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and a gap communicating with the surface of the conductive layer is formed between the platinum particles. A photoelectric conversion element comprising:   An electrode in which a conductive layer including platinum particles and a conductive binder that binds the platinum particles is formed on a substrate, and a gap communicating with the surface of the conductive layer is formed between the platinum particles. A dye-sensitized solar cell comprising:

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