Photoelectric conversion element, electronic device, and power supply module

Abstract

To provide a photoelectric conversion element capable of suppressing a decrease in output with low-illuminance light when exposed to a high-temperature light irradiation environment.SOLUTION: A photoelectric conversion element includes a first electrode, an electron transport layer, a photosensitizing compound, a hole transporting layer, and a second electrode, and the photosensitizing compound includes a compound represented by the following general formula (1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element, an electronic device, and a power supply module. [Background technology]

[0002] In recent years, solar cells, which can generate electricity efficiently even under low-illumination light, have been attracting a lot of attention. They are expected to have a wide range of applications, not only as a standalone power source that does not require battery replacement or power wiring, but also for use anywhere.

[0003] For example, amorphous silicon and organic solar cells are known as photoelectric conversion elements for indoor use. Among organic solar cells, dye-sensitized solar cells are advantageous in that they are easy to fabricate because they are composed of layers with separate charge generation and charge transport functions. In general, dye-sensitized solar cells have problems such as electrolyte volatilization and leakage because they contain electrolyte, but in recent years, solid-state dye-sensitized solar cells using P-type semiconductor materials have also been developed and are attracting attention.

[0004] In view of this, for example, a photoelectric conversion element has been described that can suppress a voltage drop and obtain a high output even in a high temperature environment or an environment with weak indoor light (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a photoelectric conversion element capable of suppressing a decrease in output power due to low-illuminance light when exposed to a high-temperature light irradiation environment. [Means for solving the problem]

[0006] The photoelectric conversion element of the present invention as a means for solving the above-mentioned problems is a photoelectric conversion element having a first electrode, an electron transport layer, a photosensitizer compound, a hole transport layer, and a second electrode, wherein the photosensitizer compound includes a compound represented by the following general formula (1) and a compound represented by the following general formula (2). [ka] In the general formula (1), Ar1 and Ar2 each represent an aryl group which may have a substituent. R1 and R2 each represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents any of the substituents represented by the following structural formulas. [ka] [ka] In the general formula (2), R3 represents an aryl group or any of the substituents represented by the following structural formulas: n represents an integer of 0 to 1. [ka] Effect of the Invention

[0007] The present invention can provide a photoelectric conversion element capable of suppressing a decrease in output power due to low-illuminance light when exposed to a high-temperature light irradiation environment. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a photoelectric conversion element according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a photoelectric conversion element according to the second embodiment. [Diagram 3] FIG. 3 is a schematic diagram illustrating an example of a photoelectric conversion element according to the third embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating an example of a photoelectric conversion element according to the fourth embodiment. [Diagram 5]FIG. 5 is a block diagram of a mouse for a personal computer as an example of the electronic device of the present invention. [Figure 6] FIG. 6 is a schematic external view showing an example of the mouse shown in FIG. [Figure 7] FIG. 7 is a block diagram of a keyboard for a personal computer as an example of the electronic device of the present invention. [Figure 8] FIG. 8 is a schematic external view showing an example of the keyboard shown in FIG. [Figure 9] FIG. 9 is a schematic external view showing another example of the keyboard shown in FIG. [Figure 10] FIG. 10 is a block diagram of a sensor as an example of an electronic device of the present invention. [Figure 11] FIG. 11 is a block diagram of a turntable as an example of an electronic device of the present invention. [Figure 12] FIG. 12 is a block diagram showing an example of an electronic device of the present invention. [Figure 13] FIG. 13 is a block diagram showing an example in which a power supply IC is further incorporated into the electronic device shown in FIG. [Figure 14] FIG. 14 is a block diagram showing an example in which a power storage device is further incorporated into the electronic device shown in FIG. [Figure 15] FIG. 15 is a block diagram showing an example of a power supply module of the present invention. [Figure 16] FIG. 16 is a block diagram showing an example in which a power storage device is further incorporated into the power supply module shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Photoelectric conversion element) The photoelectric conversion element of the present invention comprises a first electrode, an electron transport layer, a photosensitizing compound, a hole transport layer, and a second electrode, and may further comprise other layers as necessary. A photoelectric conversion element is an element that can convert light energy into electrical energy, and is used in solar cells, photodiodes, and the like.

[0010] As a result of intensive research by the present inventors to solve the above problems, it was found that in a solid-state dye-sensitized solar cell, the association state between dyes in a high-temperature light irradiation environment has a significant effect on the photoelectric conversion properties. In particular, it was found that in a solid-state dye-sensitized solar cell, the association state between dyes is important even when an organic P-type semiconductor having a large molecular size efficiently injects holes from the dye. The high temperature light irradiation environment is, for example, an environment of 50° C. and irradiation with light of 2,000 lx, such as an environment near a window irradiated with sunlight.

[0011] Therefore, the photoelectric conversion element of the present invention has a first electrode, an electron transport layer, a hole transport layer, a photosensitizer compound, and a second electrode, and the photosensitizer compound contains a compound represented by the following general formula (1) and a compound represented by the following general formula (2), thereby making it possible to prevent a decrease in output even after exposure to a high-illuminance light environment.

[0012] [ka] In the general formula (1), Ar1 and Ar2 each represent an aryl group which may have a substituent. R1 and R2 each represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents any of the substituents represented by the following structural formulas.

[0013] [ka]

[0014] [ka] In the general formula (2), R3 represents an aryl group or any of the substituents represented by the following structural formulas: n represents an integer of 0 to 1. [ka]

[0015] Each of the components of the photoelectric conversion element of the present invention will be described in detail below.

[0016] <First substrate> The shape, structure, and size of the first substrate are not particularly limited and can be appropriately selected depending on the purpose. The material of the first substrate is not particularly limited as long as it has light-transmitting and insulating properties, and can be appropriately selected according to the purpose, and examples thereof include glass, plastic film, ceramic, etc. Among these, when a firing process is included in forming the electron transport layer, a substrate having heat resistance to the firing temperature is preferred. In addition, the first substrate is preferably flexible.

[0017] <First electrode> There are no particular limitations on the shape and size of the first electrode, and they can be appropriately selected depending on the purpose. The structure of the first electrode is not particularly limited and can be appropriately selected depending on the purpose. It may be a single-layer structure or a structure in which a plurality of materials are laminated.

[0018] The material for the first electrode is not particularly limited as long as it has transparency to visible light and conductivity, and can be appropriately selected depending on the purpose. Examples of the material include transparent conductive metal oxides, carbon, and metals. Examples of transparent conductive metal oxides include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), niobium-doped tin oxide (NTO), aluminum-doped zinc oxide, indium zinc oxide, and niobium titanium oxide. Examples of carbon include carbon black, carbon nanotubes, graphene, and fullerene. Examples of metals include gold, silver, aluminum, nickel, indium, tantalum, and titanium. These may be used alone or in combination of two or more. Among these, transparent conductive metal oxides having high transparency are preferred, and ITO, FTO, ATO, and NTO are more preferred.

[0019] The average thickness of the first electrode is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 nm to 100 μm, more preferably 50 nm to 10 μm. When the material of the first electrode is carbon or metal, the average thickness of the first electrode is preferably set to an average thickness that can obtain translucency.

[0020] The first electrode can be formed by a known method such as a sputtering method, a vapor deposition method, or a spray method. The first electrode is preferably formed on a first substrate, and a commercially available integrated product in which the first electrode is formed in advance on the first substrate can be used. Examples of integrated commercially available products include FTO-coated glass, ITO-coated glass, zinc oxide:aluminum-coated glass, FTO-coated transparent plastic film, ITO-coated transparent plastic film, etc. Other integrated commercially available products include, for example, transparent electrodes in which tin oxide or indium oxide is doped with cations or anions having different valences, or glass substrates provided with metal electrodes having a structure that allows light to pass through, such as mesh-shaped or striped-shaped electrodes. These may be used alone or in combination of two or more types as a mixture or laminate. In addition, metal lead wires or the like may be used in combination for the purpose of reducing electrical resistance. Examples of materials for the metal lead wires include aluminum, copper, silver, gold, platinum, and nickel. Metal leads can be used in combination by forming them on a substrate by, for example, vapor deposition, sputtering, or pressure bonding, and then providing a layer of ITO or FTO thereon.

[0021] <Hole blocking layer> The hole blocking layer is formed between the first electrode and the electron transport layer. The hole blocking layer transports the electrons generated by the photosensitizing compound and then transported to the electron transport layer to the first electrode, and prevents contact with the hole transport layer. This makes it possible to suppress the inflow of holes into the first electrode and suppress the decrease in output caused by the recombination of electrons and holes. In a solid-type photoelectric conversion element provided with a hole transport layer, the recombination speed of holes in the hole transport material and electrons on the electrode surface is faster than that of a wet-type element using an electrolyte, so the effect of forming a hole blocking layer is very large.

[0022] The material for the hole blocking layer is not particularly limited as long as it is transparent to visible light and has electron transport properties, and can be appropriately selected depending on the purpose. Examples of the material include elemental semiconductors such as silicon and germanium, compound semiconductors typified by metal chalcogenides, and compounds having a perovskite structure.

[0023] Examples of metal chalcogenides include oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium and lead; telluride of cadmium, etc. Examples of other compound semiconductors include phosphides of zinc, gallium, indium, cadmium, etc.; gallium arsenide, copper-indium-selenide, copper-indium-sulfide, etc. Examples of compounds having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate. Among these, oxide semiconductors are preferred, with titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide and tin oxide being more preferred, and titanium oxide being even more preferred. These may be used alone or in combination of two or more. They may be a single layer or a laminate. The crystal type of these semiconductors is not particularly limited and may be appropriately selected depending on the purpose, and may be single crystal, polycrystal, or amorphous.

[0024] The method for producing the hole blocking layer is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for forming a thin film in a vacuum (vacuum film-forming method) or a wet film-forming method can be mentioned. Examples of vacuum film formation methods include sputtering, pulsed laser deposition (PLD), ion beam sputtering, ion-assisted deposition, ion plating, vacuum deposition, atomic layer deposition (ALD), and chemical vapor deposition (CVD). Examples of the wet film-forming method include the sol-gel method. The sol-gel method is a method in which a gel is produced from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then densification is promoted by heat treatment. When the sol-gel method is used, the method of applying the sol solution is not particularly limited and can be appropriately selected depending on the purpose. For example, the dipping method, the spraying method, the wire bar method, the spin coating method, the roller coating method, the blade coating method, and the gravure coating method are included. In addition, examples of the wet printing method include letterpress, offset, gravure, intaglio, rubber plate, and screen printing. In addition, the temperature during the heat treatment after applying the sol solution is preferably 80° C. or higher, more preferably 100° C. or higher. The average thickness of the hole blocking layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 nm to 1 μm, more preferably 500 nm to 700 nm in wet film formation, and more preferably 5 nm to 30 nm in dry film formation.

[0025] <Electron transport layer> The electron transport layer is formed for the purpose of transporting electrons generated in the photosensitizing compound to the first electrode or the hole blocking layer, and therefore is preferably disposed adjacent to the first electrode or the hole blocking layer. The structure of the electron transport layer is not particularly limited and can be appropriately selected according to the purpose, but it is preferable that the electron transport layers are not extended from each other in at least two adjacent photoelectric conversion elements. If the electron transport layers are not extended from each other, electron diffusion is suppressed and leakage current is reduced, which is advantageous in terms of improving light durability. In addition, the structure of the electron transport layer may be a continuous single layer, or may be a multilayer structure in which multiple layers are stacked.

[0026] The electron transport layer contains an electron transporting material and, if necessary, other materials. The electron transporting material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a semiconductor material. The semiconductor material is preferably in the form of fine particles, which are bonded together to form a porous film. A photosensitizing compound is chemically or physically adsorbed onto the surfaces of the semiconductor fine particles constituting the porous electron transport layer. The electron transport layer is preferably a porous layer made of a semiconductor material carrying the compound represented by the general formula (1) and the compound represented by the general formula (2).

[0027] The semiconductor material is not particularly limited, and any known material can be used. For example, a simple semiconductor, a compound semiconductor, or a compound having a perovskite structure can be used. Examples of elemental semiconductors include silicon and germanium. Examples of compound semiconductors include metal chalcogenides, specifically oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum, etc.; sulfides of cadmium, zinc, lead, silver, antimony, bismuth, etc.; selenides of cadmium, lead, etc.; tellurides of cadmium, etc. Other compound semiconductors include phosphides of zinc, gallium, indium, cadmium, etc., gallium arsenide, copper-indium-selenide, copper-indium-sulfide, etc. Examples of compounds having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate. Among these, oxide semiconductors are preferred, and titanium oxide, zinc oxide, tin oxide and niobium oxide are particularly preferred. When the electron transport material of the electron transport layer is titanium oxide, the conduction band is high and a high open circuit voltage is obtained. In addition, the refractive index is high and a high short circuit current is obtained due to the light confinement effect. Furthermore, a high dielectric constant and high mobility result in a high fill factor. These may be used alone or in combination of two or more. The crystal type of the semiconductor material is not particularly limited and may be appropriately selected depending on the purpose, and may be single crystal, polycrystal, or amorphous.

[0028] The number average particle size of the primary particles of the semiconductor material is not particularly limited and can be appropriately selected according to the purpose, but is preferably 1 nm or more and 100 nm or less, more preferably 5 nm or more and 50 nm or less. In addition, semiconductor materials larger than the number average particle size may be mixed or laminated, and the conversion efficiency may be improved due to the effect of scattering incident light. In this case, the number average particle size is preferably 50 nm or more and 500 nm or less. The average thickness of the electron transport layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 nm to 100 μm, more preferably 100 nm to 50 μm, and even more preferably 120 nm to 10 μm. When the average thickness of the electron transport layer is 50 nm to 100 μm, the amount of the photosensitizing compound per unit projected area can be sufficiently secured, the light capture rate can be maintained high, and the diffusion distance of the injected electrons is unlikely to increase, so that the loss due to recombination of charges can be reduced.

[0029] The method for producing the electron transport layer is not particularly limited and may be appropriately selected depending on the purpose, and examples of the method include a method for forming a thin film in a vacuum such as sputtering, a wet film-forming method, etc. Among these, from the viewpoint of production costs, the wet film-forming method is preferred, and a method in which a paste in which a powder or sol of a semiconductor material is dispersed is prepared and applied onto a first electrode as an electron collecting electrode substrate or onto a hole blocking layer is more preferred. The wet film-forming method is not particularly limited and can be appropriately selected depending on the purpose. Examples of the wet film-forming method include a dipping method, a spraying method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, and a gravure coating method. Examples of wet printing methods include letterpress, offset, gravure, intaglio, rubber plate, and screen printing.

[0030] Examples of methods for preparing a dispersion of a semiconductor material include a mechanical pulverization method using a known milling device, etc. By this method, a dispersion of a semiconductor material can be prepared by dispersing a particulate semiconductor material alone or a mixture of a semiconductor material and a resin in water or a solvent. Examples of the resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic acid esters, and methacrylic acid esters, silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, polyester resins, cellulose ester resins, cellulose ether resins, urethane resins, phenolic resins, epoxy resins, polycarbonate resins, polyarylate resins, polyamide resins, and polyimide resins. These may be used alone or in combination of two or more.

[0031] Examples of the solvent include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and α-terpineol. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ester solvents include, for example, ethyl formate, ethyl acetate, n-butyl acetate, and the like. Ether solvents include, for example, diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane, and the like. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene. The solvents may be used alone or in combination of two or more.

[0032] An acid, a surfactant, a chelating agent, or the like may be added to a dispersion liquid containing a semiconductor material, or a paste containing a semiconductor material obtained by a sol-gel method or the like, in order to prevent re-aggregation of particles. Examples of the acid include hydrochloric acid, nitric acid, and acetic acid. An example of the surfactant is polyoxyethylene octylphenyl ether. Chelating agents include, for example, acetylacetone, 2-aminoethanol, ethylenediamine, and the like.

[0033] A thickener may also be added to improve film-forming properties. Examples of thickeners include polyethylene glycol, polyvinyl alcohol, and ethyl cellulose. After the semiconductor material is applied, the semiconductor material particles can be brought into electronic contact with each other, and the film can be baked, irradiated with microwaves or electron beams, or irradiated with laser light in order to improve the film strength and adhesion to the substrate. These treatments can be performed alone or in combination of two or more. When an electron transport layer formed from a semiconductor material is baked, the baking temperature is not particularly limited and can be appropriately selected depending on the purpose, but since a temperature that is too high may increase the resistance of the substrate or cause melting, the baking temperature is preferably 30° C. to 700° C., and more preferably 100° C. to 600° C. The baking time is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 minutes to 10 hours.

[0034] When an electron transport layer made of a semiconductor material is irradiated with microwaves, the irradiation time is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 hour or less. In this case, irradiation may be performed from the side on which the electron transport layer is formed, or from the side on which the electron transport layer is not formed. After baking the electron transport layer made of a semiconductor material, for the purpose of increasing the surface area of ​​the electron transport layer and increasing the efficiency of electron injection from the photosensitizing compound described below to the semiconductor material, for example, chemical plating using an aqueous solution of titanium tetrachloride or a mixed solution of titanium tetrachloride and an organic solvent or electrochemical plating using an aqueous solution of titanium trichloride may be performed. A film obtained by sintering a semiconductor material with a diameter of several tens of nanometers can be formed into a porous structure. Such a nanoporous structure has a very high surface area, which can be expressed by a roughness factor. The roughness factor is a value that represents the actual area inside the porous structure relative to the area of ​​the semiconductor particles applied to the first substrate. Therefore, the larger the roughness factor, the better, but in relation to the average thickness of the electron transport layer, a roughness factor of 20 or more is preferable.

[0035] The particles of the electron transport material may be doped with a lithium compound. Specifically, a solution of a lithium bis(trifluoromethanesulfonimide) compound is deposited on the particles of the electron transport material by spin coating or the like, and then the particles are baked. The lithium compound is not particularly limited and can be appropriately selected depending on the purpose. Examples of the lithium compound include lithium bis(trifluoromethanesulfonimide), lithium bis(fluoromethanesulfonimide), lithium bis(fluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, lithium perchlorate, and lithium iodide.

[0036] <Photosensitizing compound> The photosensitizing compound is a compound that is photoexcited by light irradiated to a photoelectric conversion element, and in order to further improve the output and photoelectric conversion efficiency, the photosensitizing compound is adsorbed onto the surface of the semiconductor material that constitutes the electron transport layer. The photosensitizing compound is a compound represented by the following general formula (1) and a compound represented by the following general formula (2). When the electron transport layer contains the compound represented by the following general formula (1) and the compound represented by the following general formula (2) as the photosensitizing compound, the compound represented by the general formula (1) and the compound represented by the following general formula (2) are in a mixed adsorption state, and a high output in a high temperature environment can be obtained in a solid-state dye-sensitized solar cell.

[0037] [ka] In the general formula (1), Ar1 and Ar2 each represent an aryl group which may have a substituent. R1 and R2 each represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents any of the substituents represented by the following structural formulas.

[0038] [ka] Examples of the aryl group of Ar1 and Ar2 include a phenyl group, a naphthyl group, and a biphenyl group. Examples of the substituent include an alkyl group and an alkoxy group.

[0039] [ka] In the general formula (2), R3 represents an aryl group or any of the substituents represented by the following structural formulas: n represents an integer of 0 to 1. [ka]

[0040] The compound represented by the general formula (1) is preferably a compound represented by the following general formula (3) since it can provide high output in a range of light environments from low to high illuminance. An example of low illuminance light is 500 lx light, and an example of high illuminance light is 50° C. and 2,000 lx light.

[0041] [ka] In the general formula (3), Ar4 and Ar5 each represent a phenyl group which may have a substituent, or a naphthyl group which may have a substituent, and Ar6 represents a phenyl group or a thiophene group. Examples of the substituent include an alkyl group and an alkoxy group.

[0042] Specific examples of the basic compounds represented by the above general formula (1) and general formula (3) are shown below, but the present invention is not limited to these.

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] [ka]

[0048] Specific examples of the photosensitizing compound represented by the above general formula (2) are shown below, but the present invention is not limited to these.

[0049] [ka] (B2-1) TIFF0007639427000020.tif57130(B2-2) TIFF0007639427000021.tif62127(B2-3) TIFF0007639427000022.tif63106(B2-4) TIFF0007639427000023.tif57125(B2-5) TIFF0007639427000024.tif57125(B2-6)

[0050] As a method for adsorbing a photosensitizing compound on the surface of the semiconductor material of the electron transport layer, a method of immersing an electron transport layer containing a semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, a method of applying a solution of the photosensitizing compound or a dispersion of the photosensitizing compound to the electron transport layer and adsorbing the same, etc. can be used. In the case of immersing an electron transport layer formed with a semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, an immersion method, a dip method, a roller method, an air knife method, etc. can be used. In the case of applying a solution of the photosensitizing compound or a dispersion of the photosensitizing compound to the electron transport layer and adsorbing the same, a wire bar method, a slide hopper method, an extrusion method, a curtain method, a spin method, a spray method, etc. can be used. It is also possible to adsorb the same in a supercritical fluid using carbon dioxide or the like.

[0051] When the photosensitizing compound is adsorbed onto the semiconductor material, a condensing agent may be used in combination. The condensation agent may be either one that acts catalytically to physically or chemically bind the photosensitizing compound to the surface of the semiconductor material, or one that acts stoichiometrically to favorably shift the chemical equilibrium. Furthermore, a thiol or hydroxy compound may be added as a condensation assistant.

[0052] Examples of the solvent that dissolves or disperses the photosensitizing compound include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of the alcohol solvent include methanol, ethanol, and isopropyl alcohol. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ester solvents include, for example, ethyl formate, ethyl acetate, n-butyl acetate, and the like. Ether solvents include, for example, diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane, and the like. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene. These may be used alone or in combination of two or more.

[0053] Since some photosensitizing compounds work more effectively when their aggregation is suppressed, an aggregating agent may be used in combination. Examples of the aggregating agent include steroid compounds such as cholic acid and chenodeoxycholic acid, long-chain alkyl carboxylic acids, and long-chain alkyl phosphonic acids, and 4-benzyloxybenzoic acid is particularly preferred.

[0054] The content of the aggregation dissociation agent is preferably 0.5 to 100 parts by mol, more preferably 10 to 50 parts by mol, relative to 1 part by mol of the photosensitizing compound.

[0055] The temperature when the photosensitizer compound, or the photosensitizer compound and the aggregation dissociation agent are adsorbed on the surface of the semiconductor material constituting the electron transport layer is preferably -50°C or more and 200°C or less. The adsorption time is preferably 5 seconds to 1,000 hours, more preferably 10 seconds to 500 hours, and even more preferably 1 minute to 150 hours. The adsorption step is preferably performed in a dark place. The adsorption step may be performed by leaving the mixture at rest or by stirring. The stirring method is not particularly limited and may be appropriately selected depending on the purpose. For example, a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor, a disperser, ultrasonic dispersion, or the like may be used.

[0056] <Hole transport layer> The hole transport layer is not particularly limited as long as it has a function of transporting holes, and a known material can be used, for example, an electrolyte solution in which a redox pair is dissolved in an organic solvent, a gel electrolyte in which a polymer matrix is ​​impregnated with a liquid in which a redox pair is dissolved in an organic solvent, a molten salt containing a redox pair, a solid electrolyte, an inorganic hole transport material, an organic hole transport material, etc. Among these, although an electrolyte solution or a gel electrolyte can be used, a solid electrolyte is preferred, and an organic hole transport material is more preferred.

[0057] The hole transport layer preferably further contains an alkali metal salt, which can improve the output and can also improve the light irradiation resistance and high-temperature storage resistance. Specific examples of the alkali metal salt include the following (C-1) to (C-86), but are not limited thereto.

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] Among these, lithium bis(trifluoromethanesulfonylimide) (Li-TFSI) and lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (Li-FTFSI) are preferred, and lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (Li-FTFSI) is particularly preferred.

[0063] The content of the alkali metal salt is preferably from 5 mol % to 50 mol % and more preferably from 20 mol % to 35 mol % based on the total amount of the hole transport material.

[0064] The hole transport layer preferably contains a basic compound represented by the following general formula (5). [ka] In the general formula (5), Ar7 and Ar8 each represent an aryl group which may have a substituent. Examples of the aryl group of Ar7 and Ar8 include a phenyl group, a naphthyl group, a biphenyl group, etc. Examples of the substituent include an alkyl group, an alkoxy group, etc.

[0065] The hole transport layer preferably contains a basic compound represented by the above general formula (5). When the hole transport layer contains a basic compound represented by the above general formula (5), it is advantageous in terms of increasing the output stability of the photoelectric conversion element. In particular, it is advantageous in terms of reducing the variation in output characteristics for low illuminance light and enabling stable power generation.

[0066] Specific examples of the basic compound represented by the above general formula (5) are shown below, but the present invention is not limited to these.

[0067] [ka]

[0068] In addition to the basic compound represented by the above general formula (5), basic compounds such as 4-dimethylaminopyridine (DMAP), 4-pyrrolidinopyridine (PYP), 4-piperidinopyridine (PPP), and tertiary butylpyridine (TBP) are also preferred.

[0069] The content of the basic compound represented by the above general formula (5) in the hole transport layer is preferably 20 mol % to 65 mol %, more preferably 35 mol % to 50 mol %, based on the hole transport material. When the content of the basic compound is within the preferred range, a high open circuit voltage can be maintained, a high output can be obtained, and high stability and durability can be obtained even when used for a long period of time in various environments.

[0070] The hole transport layer contains a hole transport material or a P-type semiconductor material to obtain the function of transporting holes. As the hole transport material or the P-type semiconductor material, a known organic hole transport compound is used. Specific examples thereof include oxadiazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, oxadiazole compounds, tetraarylbenzidine compounds, stilbene compounds, spiro compounds, etc. Among these, spiro compounds are more preferable.

[0071] As the spiro type compound, a compound containing the following general formula (7) is preferable. [ka] In the general formula (7), R4 to R7 each independently represent a substituted amino group such as a dimethylamino group, a diphenylamino group, or a naphthyl-4-tolylamino group.

[0072] The spiro compound is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include, but are not limited to, the following exemplary compounds (D-1) to (D-20). These may be used alone or in combination of two or more.

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] These spiro compounds have high hole mobility, and because two benzidine skeleton molecules are twisted and bonded, they form a nearly spherical electron cloud, and because of their good intermolecular hopping conductivity, they exhibit excellent photoelectric conversion properties. They also have high solubility, so they dissolve in various organic solvents, and because they are amorphous (amorphous substances that do not have a crystal structure), they are easily densely packed into porous electron transport layers. Furthermore, because they do not have light absorption characteristics above 450 nm, they can efficiently absorb light in the photosensitizing compound, making them particularly suitable for solid-state dye-sensitized solar cells.

[0081] In addition to the hole transport material and the basic compound, it is preferable to add an oxidizing agent to the hole transport layer, which improves the electrical conductivity and enhances the durability and stability of the output characteristics. Examples of the oxidizing agent include tris(4-bromophenyl)aminium hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluoroborate, silver nitrate, metal complexes, and hypervalent iodine compounds, among which metal complexes are more preferred. Hypervalent iodine compounds are even more preferred. When the oxidizing agent is a metal complex or a hypervalent iodine compound, it is advantageous in that it has high solubility in organic solvents and can be added in large amounts. A metal complex is composed of a metal cation, a ligand, and an anion. Examples of metal cations include chromium, manganese, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, gold, platinum, and other cations. Among these, cobalt, iron, nickel, and copper cations are preferred, and cobalt complexes are more preferred. As the ligand, those containing at least one nitrogen-containing 5- and / or 6-membered heterocycles are preferred, and may have a substituent. Specific examples include, but are not limited to, the following:

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] Examples of anions include hydride ions (H - ), fluoride ion (F -), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ), hydroxide ion (OH - ), cyanide ion (CN - ), nitrate ion (NO3 - ), nitrite ion (NO2 - ), hypochlorite ion (ClO - ), chlorite ion (ClO2 - ), chlorate ion (ClO3 - ), perchlorate ion (ClO4 - ), permanganate ion (MnO4 - ), acetate ion (CHCOO - ), hydrogen carbonate ion (HCO3 - ), dihydrogen phosphate ion (H2PO4 - ), hydrogen sulfate ion (HSO4 - ), hydrogen sulfide ion (HS - ), thiocyanate ion (SCN - ), tetrafluoroborate ion (BF4 - ), hexafluorophosphate ion (PF6 - ), tetracyanoborate ion (B(CN)4 - ), dicyanoamine ion (N(CN)2 - ), p-toluenesulfonate ion (TsO - ), trifluoromethylsulfonate ion (CF3SO 2- ), bis(trifluoromethylsulfonyl)amine ion (N(SO2CF3) 2- ), tetrahydroxoaluminate ion ([Al(OH)4] - , or [Al(OH)4(H2O)2] - ), dicyanoargentate(I) ion ([Ag(CN)2] - ), tetrahydroxochromate(III) ion ([Cr(OH)4] - ), tetrachloroaurate(III) ion ([AuCl4] - ), oxide ions (O2 - ), sulfide ion (S2 - ), peroxide ion (O2 2-), sulfate ion (SO4 2- ), sulfite ion (SO3 2- ), thiosulfate ion (S2O3 2- ), carbonate ion (CO3 2- ), chromate ion (CrO4 2- ), dichromate ion (Cr2O7 2- ), monohydrogen phosphate ion (HPO4 2- ), tetrahydroxozincate(II) ion ([Zn(OH)4] 2- ), tetracyanozinc(II) ion ([Zn(CN)4] 2- ), tetrachlorocuprate(II) ion ([CuCl4] 2- ), phosphate ion (PO4 3- ), ferricyanide(III) ion ([Fe(CN)6] 3- ), bis(thiosulfato)argentate(I) ion ([Ag(S2O3)2] 3- ), ferricyanide(II) ion ([Fe(CN)6] 4- These may be used alone or in combination of two or more. Among these, tetrafluoroborate ion, hexafluorophosphate ion, tetracyanoborate ion, bis(trifluoromethylsulfonyl)amine ion, and perchlorate ion are preferable.

[0086] Among these metal complexes, trivalent cobalt complexes represented by the following structural formulas (8) and (9) are preferred: When the metal complex is a trivalent cobalt complex, it is advantageous in terms of oxidizing the hole transport material.

[0087] [ka]

[0088] [ka]

[0089] More preferred is a trivalent cobalt complex represented by the following general formula (4). [ka] In the general formula (4), R3 to R5 each represent a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group. Y represents a group represented by the following structural formula: 1 )from( 4 ) indicates one of the following: [ka]

[0090] Examples of the trivalent cobalt complex represented by the above general formula (4) include (F-1) to (F-16) shown below, but are not limited thereto.

[0091] [ka] [ka]

[0092] The hole transport layer may be a single-layer structure made of a single material, or may be a laminate structure containing a plurality of compounds. When the hole transport layer is a laminate structure, it is preferable to use a polymer material for the hole transport layer close to the second electrode. The use of a polymer material with excellent film-forming properties is advantageous in that the surface of the porous electron transport layer can be made smoother and the photoelectric conversion characteristics can be improved. In addition, since the polymer material does not easily penetrate into the porous electron transport layer, it has excellent coverage of the surface of the porous electron transport layer, and may be effective in preventing short circuits when providing an electrode.

[0093] The polymer material used for the hole transport layer may be any known hole transport polymer material. Examples of the hole transporting polymeric material include polythiophene compounds, polyphenylenevinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiadiazole compounds.

[0094] Examples of the polythiophene compound include poly(3-n-hexylthiophene), poly(3-n-octyloxythiophene), poly(9,9'-dioctyl-fluorene-co-bithiophene), poly(3,3'''-didodecyl-quaterthiophene), poly(3,6-dioctylthieno[3,2-b]thiophene), poly(2,5-bis(3-decylthiophen-2-yl)thieno[3, 2-b]thiophene), poly(3,4-didecylthiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene-co-thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene-co-bithiophene).

[0095] Examples of the polyphenylenevinylene compound include poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene], and poly[(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene)-co-(4,4'-biphenylenevinylene)].

[0096] Examples of polyfluorene compounds include poly(9,9'-didodecylfluorenyl-2,7-diyl), poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(9,10-anthracene)], poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(4,4'-biphenylene)], poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene)], and poly[(9,9-dioctyl-2,7-diyl)-co-(1,4-(2,5-dihexyloxy)benzene)].

[0097] Examples of the polyphenylene compound include poly[2,5-dioctyloxy-1,4-phenylene] and poly[2,5-di(2-ethylhexyloxy-1,4-phenylene].

[0098] Examples of the polyarylamine compound include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N'-diphenyl)-N,N'-di(p-hexylphenyl)-1,4-diaminobenzene], poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], poly[(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], poly poly[(N,N'-bis(4-(2-ethylhexyloxy)phenyl)benzidine-N,N'-(1,4-diphenylene)], poly[phenylimino-1,4-phenylenevinylene-2,5-dioctyloxy-1,4-phenylenevinylene-1,4-phenylene], poly[p-tolylimino-1,4-phenylenevinylene-2,5-di(2-ethylhexyloxy)-1,4-phenylenevinylene-1,4-phenylene], poly[4-(2-ethylhexyloxy)phenylimino-1,4-biphenylene], and the like.

[0099] Examples of the polythiadiazole compound include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo(2,1',3)thiadiazole] and poly(3,4-didecylthiophene-co-(1,4-benzo(2,1',3)thiadiazole).

[0100] Among the hole transporting polymer materials, polythiophene compounds and polyarylamine compounds are preferred from the viewpoints of carrier mobility and ionization potential.

[0101] The average thickness of the hole transport layer is not particularly limited and may be appropriately selected depending on the purpose. However, it is preferable that the hole transport layer has a structure in which the hole transport layer penetrates into the pores of the porous electron transport layer, and the average thickness of the hole transport layer is preferably 0.01 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less, and even more preferably 0.2 μm or more and 2 μm or less.

[0102] The hole transport layer can be formed directly on the electron transport layer to which the photosensitizing compound is adsorbed. The method for producing the hole transport layer is not particularly limited and can be appropriately selected depending on the purpose, and includes a method for forming a thin film in a vacuum such as vacuum deposition, a wet film forming method, etc. Among these, in terms of production cost, etc., the wet film forming method is particularly preferred, and the method of coating on the electron transport layer is preferred. When a wet film-forming method is used, the coating method is not particularly limited and can be performed according to a known method. For example, a dipping method, a spraying method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, or a gravure coating method can be used. In addition, as a wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used.

[0103] Alternatively, a membrane may be formed in a supercritical fluid or a subcritical fluid at a temperature and pressure lower than the critical point. The supercritical fluid is not particularly limited as long as it exists as a non-aggregating high-density fluid in a temperature and pressure region exceeding the limit (critical point) at which gas and liquid can coexist, does not aggregate even when compressed, and is in a state of not less than the critical temperature and not less than the critical pressure, and can be appropriately selected depending on the purpose, but a fluid with a low critical temperature is preferred.

[0104] Examples of supercritical fluids include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, and ether solvents.

[0105] Examples of the alcohol solvent include methanol, ethanol, and n-butanol.

[0106] Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene, etc. Examples of the halogen solvent include methylene chloride, chlorotrifluoromethane, etc.

[0107] An example of the ether solvent is dimethyl ether.

[0108] These may be used alone or in combination of two or more. Among these, carbon dioxide is preferred because it has a critical pressure of 7.3 MPa and a critical temperature of 31° C., and therefore can easily produce a supercritical state, and is non-flammable and easy to handle.

[0109] The subcritical fluid is not particularly limited as long as it exists as a high-pressure liquid in the temperature and pressure range near the critical point, and can be appropriately selected depending on the purpose. Compounds listed as supercritical fluids can also be suitably used as subcritical fluids.

[0110] The critical temperature and critical pressure of the supercritical fluid are not particularly limited and can be appropriately selected depending on the purpose, but the critical temperature is preferably from -273°C to 300°C, more preferably from 0°C to 200°C.

[0111] Furthermore, in addition to the supercritical fluid and the subcritical fluid, an organic solvent and an entrainer can be used in combination. By adding the organic solvent and the entrainer, it is possible to more easily adjust the solubility in the supercritical fluid. The organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the organic solvent include ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents.

[0112] Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0113] Ester solvents include, for example, ethyl formate, ethyl acetate, n-butyl acetate, and the like.

[0114] Examples of ether solvents include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane.

[0115] Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0116] Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0117] Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene.

[0118] The organic solvents may be used alone or in combination of two or more kinds.

[0119] Alternatively, a hole transport material may be laminated on the electron transport layer having the photosensitizing compound adsorbed thereon, followed by a press treatment step, which may improve efficiency by allowing the hole transport material to adhere more closely to the electron transport layer, which is a porous electrode, through the press treatment. The method of pressing is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a press molding method using a flat plate such as an IR tablet molding machine, and a roll pressing method using rollers or the like. The pressure is 10kgf / cm 2 More than 30kgf / cm is preferable. 2The above is more preferable. The time for the press treatment is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 hour or less. Heat may be applied during the press treatment. During the press treatment, a release agent may be placed between the press machine and the electrode.

[0120] Examples of the release agent include fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, perfluoroalkoxy fluoride resin, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, and polyvinyl fluoride. These may be used alone or in combination of two or more. After the pressing step, and prior to providing the second electrode, a metal oxide may be provided between the hole transport material and the second electrode. Examples of metal oxides include molybdenum oxide, tungsten oxide, vanadium oxide, nickel oxide, etc. These may be used alone or in combination of two or more. Among these, molybdenum oxide is preferred. The method for providing the metal oxide on the hole transport layer is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a method for forming a thin film in a vacuum such as sputtering or vacuum deposition, and a wet film formation method. As the wet film-forming method, a method of preparing a paste in which a powder or sol of a metal oxide is dispersed and applying it on the hole transport layer is preferred. When using the wet film-forming method, the application method is not particularly limited and can be performed according to a known method, for example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method, and as a wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used. The average thickness of the applied metal oxide is preferably from 0.1 nm to 50 nm, and more preferably from 1 nm to 10 nm.

[0121] <Second electrode> The second electrode can be formed on the hole transport layer or on the metal oxide in the hole transport layer. The second electrode can be the same as the first electrode, and does not necessarily require a support as long as it has sufficient strength. Examples of materials for the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers. Examples of metals include platinum, gold, silver, copper, and aluminum. Examples of carbon compounds include graphite, fullerene, carbon nanotubes, and graphene. Examples of the conductive metal oxide include ITO, FTO, and ATO. Examples of the conductive polymer include polythiophene and polyaniline. These may be used alone or in combination of two or more. The second electrode can be formed on the hole transport layer by a suitable method such as coating, lamination, deposition, CVD, or bonding, depending on the type of material used and the type of hole transport layer. In the photoelectric conversion element, it is preferable that at least one of the first electrode and the second electrode is substantially transparent. It is preferable that the first electrode side is transparent and incident light is made incident from the first electrode side. In this case, it is preferable to use a material that reflects light on the second electrode side, and metal, glass on which a conductive oxide is vapor-deposited, plastic, or a metal thin film is preferably used. In addition, providing an anti-reflection layer on the incident light side is also an effective means.

[0122] <Second board> The second substrate is not particularly limited and may be a known one, such as a substrate made of glass, a plastic film, a ceramic, etc. A concave-convex portion may be formed at the joint between the second substrate and the sealing member to improve adhesion. The method for forming the uneven portion is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include sand blasting, water blasting, abrasive paper, chemical etching, and laser processing. The adhesion between the second substrate and the sealing member can be improved by, for example, removing organic matter from the surface or improving hydrophilicity. The method for removing organic matter from the surface of the second substrate is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include UV ozone cleaning and oxygen plasma treatment.

[0123] <Sealing member> Examples of the sealing resin include acrylic resin, epoxy resin, and low-melting glass resin. As the cured acrylic resin, any known material can be used as long as it is a cured material of a monomer or oligomer having an acrylic group in the molecule. As the cured epoxy resin, any known material can be used as long as it is a cured material of a monomer or oligomer having an epoxy group in the molecule. Examples of epoxy resins include water-dispersed, solvent-free, solid, heat-cured, mixed-curing, and UV-cured. Of these, heat-cured and UV-cured are preferred, and UV-cured is more preferred. Even in the case of UV-cured, it is possible to heat the resin, and it is preferred to heat the resin after UV-curing. Examples of epoxy resins include bisphenol A type, bisphenol F type, novolac type, cyclic aliphatic type, long chain aliphatic type, glycidyl amine type, glycidyl ether type, glycidyl ester type, etc. These may be used alone or in combination of two or more types. It is preferable to mix a curing agent and various additives into the epoxy resin as necessary.

[0124] The curing agent is classified into amine-based, acid anhydride-based, polyamide-based and other curing agents, and is appropriately selected depending on the purpose. Examples of the amine-based curing agent include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone. Examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, HET acid anhydride, and dodecenylsuccinic anhydride. Examples of other curing agents include imidazoles, polymercaptans, etc. These may be used alone or in combination of two or more.

[0125] Examples of additives include a filler, a gap agent, a polymerization initiator, a drying agent (moisture absorbent), a hardening accelerator, a coupling agent, a flexibilizing agent, a colorant, a flame retardant assistant, an antioxidant, an organic solvent, etc. Among these, the filler, the gap agent, the hardening accelerator, the polymerization initiator, and the drying agent (moisture absorbent) are preferred, and the filler and the polymerization initiator are more preferred. The filler is effective in suppressing the intrusion of moisture and oxygen, and also has the effects of reducing volumetric shrinkage during curing, reducing the amount of outgassing during curing or heating, improving mechanical strength, and controlling thermal conductivity and fluidity, making it extremely effective in maintaining stable output in various environments. In particular, the output characteristics and durability of a photoelectric conversion element are not only affected by the intrusion of moisture and oxygen, but also by the influence of outgassing generated during curing or heating of the sealing member, which cannot be ignored. In particular, the influence of outgassing generated during heating has a significant effect on output characteristics during storage in a high-temperature environment. In this case, by incorporating a filler, gap agent, or desiccant into the sealing material, these materials themselves can suppress the intrusion of moisture and oxygen, and by reducing the amount of sealing material used, it is possible to obtain the effect of reducing outgassing. This is effective not only during curing, but also when the photoelectric conversion element is stored in a high-temperature environment.

[0126] The filler is not particularly limited, and known fillers can be used. For example, inorganic fillers such as crystalline or amorphous silica, talc, alumina, aluminum nitride, silicon nitride, calcium silicate, and calcium carbonate are preferably used. These may be used alone or in combination of two or more. The average primary particle size of the filler is preferably 0.1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. When the amount of addition is within the preferred range, the effect of suppressing the intrusion of moisture and oxygen can be sufficiently obtained, the viscosity becomes appropriate, and it is effective in improving adhesion and defoaming with the substrate, or in controlling the width of the sealing part and in workability. The content of the filler is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the entire sealing member. When the content of the filler is within the above range, a sufficient effect of suppressing the intrusion of moisture and oxygen is obtained, the viscosity is appropriate, and the adhesion and workability are also good.

[0127] The gap agent is also called a gap control agent or spacer agent, and it makes it possible to control the gap of the sealing part. For example, when a sealing member is applied on a first substrate or a first electrode, and a second substrate is placed on top of that for sealing, the gap of the sealing part is made equal to the size of the gap agent by mixing the gap agent into the epoxy resin, so that the gap of the sealing part can be easily controlled. As the gap agent, any known material can be used as long as it is granular, has a uniform particle size, and has high solvent resistance and heat resistance. It is preferable that the material has a high affinity with the epoxy resin and a spherical particle shape. Specifically, glass beads, silica fine particles, organic resin fine particles, etc. can be mentioned. These may be used alone or in combination of two or more types. The particle size of the gap agent can be selected according to the gap of the sealing portion to be set, but is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

[0128] A polymerization initiator is a material that is added for the purpose of initiating polymerization using heat or light. A thermal polymerization initiator is a compound that generates active species such as radicals and cations by heating. Specifically, an azo compound such as 2,2'-azobisbutyronitrile (AIBN) or a peroxide such as benzoyl peroxide (BPO) is used. A benzenesulfonate ester or an alkylsulfonium salt is used as a thermal cationic polymerization initiator. On the other hand, a photo-polymerization initiator is preferably used in the case of an epoxy resin. When an epoxy resin is mixed with a photo-cationic polymerization initiator and irradiated with light, the photo-cationic polymerization initiator decomposes to generate a strong acid, which causes the epoxy resin to polymerize and the curing reaction proceeds. A photo-cationic polymerization initiator has the effects of having little volume shrinkage during curing, not being inhibited by oxygen, and having high storage stability.

[0129] Examples of the photocationic polymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, methacerone compounds, and silanol-aluminum complexes. In addition, a photoacid generator having a function of generating an acid by irradiation with light can also be used. The photoacid generator acts as an acid that initiates cationic polymerization, and examples of the photoacid generator include onium salts such as ionic sulfonium salts and iodonium salts that are composed of a cationic moiety and an anionic moiety. These may be used alone or in combination of two or more kinds. The amount of the polymerization initiator to be added may vary depending on the material used, but is preferably 0.5 parts by mass to 10 parts by mass, more preferably 1 part by mass to 5 parts by mass, relative to 100 parts by mass of the entire sealing member. By adding an amount within the above range, curing can proceed appropriately, the amount of uncured material remaining can be reduced, and excessive outgassing can be prevented, which is effective.

[0130] A desiccant, also known as a moisture absorbent, is a material that has the function of physically or chemically adsorbing or absorbing moisture. When contained in a sealing material, it is effective because it can further increase moisture resistance and in some cases reduce the effects of outgassing. The desiccant is preferably particulate, and examples thereof include inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolite. Among these, zeolite, which has a large moisture absorption capacity, is preferred. These may be used alone or in combination of two or more.

[0131] A curing accelerator, also called a curing catalyst, is used for the purpose of accelerating the curing speed, and is mainly used for thermosetting epoxy resins. Examples of the curing accelerator include tertiary amines or tertiary amine salts such as DBU (1,8-diazabicyclo(5,4,0)-undecene-7) and DBN (1,5-diazabicyclo(4,3,0)-nonene-5), imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, and phosphines or phosphonium salts such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate. These may be used alone or in combination of two or more.

[0132] The coupling agent has the effect of increasing molecular bonding strength, and examples thereof include silane coupling agents, such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyltrimethoxysilane. These may be used alone or in combination of two or more.

[0133] After application, the low-melting glass resin is baked at about 550°C to break down the resin components, and then melted with an infrared laser or similar to adhere to the glass substrate. At this time, the low-melting glass components diffuse into the metal oxide layer and are physically bonded together, providing high sealing performance. In addition, because the resin components are gone, no outgassing occurs, as occurs with acrylic resin or epoxy resin, and the photoelectric conversion element is not degraded. Furthermore, epoxy resin compositions commercially available as sealing materials, sealants, or adhesives are known as sealing members, and can be effectively used in the present invention. Among them, there are also epoxy resin compositions developed and commercially available for use in solar cells and organic EL elements, which can be particularly effectively used in the present invention. Examples include TB3118, TB3114, TB3124, TB3125F (manufactured by ThreeBond Co., Ltd.), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyoritsu Chemical Co., Ltd.), and WB90US(P) (manufactured by Moresco Co., Ltd.).

[0134] In the present invention, a sheet-shaped sealing material can be used. The sheet-like sealing material is a sheet on which an epoxy resin layer is formed in advance, and the sheet is made of glass or a film with high gas barrier properties, and corresponds to the second substrate in the present invention. The sheet-like sealing material is attached to the second substrate and then cured, thereby forming the sealing member and the second substrate at the same time. Depending on the formation pattern of the epoxy resin layer formed on the sheet, a structure with a hollow portion can be effectively formed. The method for forming the sealing member is not particularly limited and can be performed according to a known method. For example, various methods such as a dispense method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method, a letterpress method, an offset method, an intaglio method, a rubber plate method, and a screen printing method can be used. Furthermore, a passivation layer may be provided between the sealing member and the second electrode. The passivation layer is not particularly limited as long as it is arranged so that the sealing member does not come into contact with the second electrode, and can be appropriately selected depending on the purpose, but aluminum oxide, silicon nitride, silicon oxide, etc. are preferably used.

[0135] Next, the photoelectric conversion element of the present invention will be described with reference to the drawings. However, the present invention is not limited thereto, and for example, the number, position, shape, etc. of the following components not described in the present embodiment are also included in the scope of the present invention.

[0136] <First embodiment> FIG. 1 is a schematic diagram showing an example of a photoelectric conversion element of the first embodiment. In the photoelectric conversion element 101 of the first embodiment of FIG. 1, a first electrode 2 is formed on a first substrate 1. An electron transport layer 4 is formed on the first electrode 2, and a photosensitizing compound 5 is adsorbed on the surface of the electron transport material constituting the electron transport layer 4. A hole transport layer 6 is formed on and inside the electron transport layer 4, and a second electrode 7 is formed on the hole transport layer 6. A second substrate 9 is disposed above the second electrode 7, and the second substrate 9 is fixed between the second substrate 7 and the first electrode 2 by a sealing member 8. The photoelectric conversion element 101 of the first embodiment in FIG. 1 has a hollow portion 10 between the second electrode 7 and the second substrate 9. By having the hollow portion 10, it is possible to control the moisture content and oxygen concentration in the hollow portion, which has the advantage of improving the power generation performance and its durability. Furthermore, since the second electrode 7 and the second substrate 9 are not in contact with each other, peeling or damage of the second electrode 7 can be prevented. The oxygen concentration in the hollow portion is not particularly limited and can be freely selected, but is preferably 0% or more and 21% or less, and more preferably 5% or more and 15% or less. Although not shown, the first electrode 2 and the second electrode 7 each have a path leading to an electrode extraction terminal.

[0137] <Second embodiment> FIG. 2 is a schematic diagram showing an example of a photoelectric conversion element according to the second embodiment. In the photoelectric conversion element 101 according to the second embodiment shown in FIG. 2, a hole blocking layer 3 is formed between a first substrate 1 and an electron transport layer 4. By forming the hole blocking layer 3, it is possible to prevent recombination of electrons and holes, which is effective in improving power generation performance. The photoelectric conversion element shown in FIG. 2 has a hollow portion 10 between a second electrode 7 and a second substrate 9, similar to FIG. 1.

[0138] <Third embodiment> FIG. 3 is a schematic diagram showing an example of a photoelectric conversion element according to the third embodiment. The photoelectric conversion element 101 according to the third embodiment shown in FIG. 3 does not have a hollow portion in the sealing portion, and the hollow portion 10 shown in FIG. 2 is covered with a sealing member 8. For example, the sealing member 8 can be applied to the entire surface of the second electrode 7, and the second substrate 9 is provided thereon, or the above-mentioned sheet-like sealing material can be used. In this case, the hollow portion inside the sealing may be completely eliminated, or a part of the hollow portion may be left. In this way, by covering almost the entire surface with the sealing member, it is possible to reduce peeling or destruction of the second substrate 9, and to increase the mechanical strength of the photoelectric conversion element.

[0139] <Fourth embodiment> Fig. 4 is a schematic diagram showing an example of a photoelectric conversion element of the fourth embodiment. In the photoelectric conversion element 101 of the fourth embodiment of Fig. 4, a sealing member 8 is bonded to a first substrate 1 and a second substrate 9. This configuration improves the adhesion of the sealing member 8 to the substrates, and provides the effect of increasing the mechanical strength of the photoelectric conversion element. In addition, the increased adhesion can further improve the sealing effect that prevents the intrusion of moisture and oxygen.

[0140] (Photoelectric conversion element module) In the photoelectric conversion element module of the present invention, the photoelectric conversion elements of the present invention are electrically connected in series or in parallel. The photoelectric conversion element module of the present invention has, for example, a photoelectric conversion element arrangement region in which a plurality of photoelectric conversion elements are arranged adjacent to each other and connected in series or in parallel, and a photoelectric conversion layer including an electron transport layer and a hole transport layer is formed between a first electrode and a second electrode of the plurality of photoelectric conversion elements. The photoelectric conversion element module of the present invention may have a configuration including a plurality of the photoelectric conversion elements. The plurality of photoelectric conversion elements may be connected in series and / or parallel, or may include independent photoelectric conversion elements that are not connected. The configuration of each layer of the photoelectric conversion element module may be the same as that of the photoelectric conversion element. The structure of the photoelectric conversion element module is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the first electrode, the electron transport layer, and the second electrode are divided in at least two adjacent photoelectric conversion elements, which can reduce the risk of short circuiting. On the other hand, the hole transport layer may be divided in at least two adjacent photoelectric conversion elements, or may be in the form of a continuous layer in which the hole transport layers extend from each other. The photoelectric conversion element module may also be configured such that, in at least two of the photoelectric conversion elements adjacent to each other, the first electrode of one of the photoelectric conversion elements and the second electrode of the other of the photoelectric conversion elements are electrically connected by a conductive portion that penetrates at least from the hole transport layer to the hole blocking layer. The photoelectric conversion element module can have a pair of substrates, and a photoelectric conversion element arrangement area connected in series or in parallel between the pair of substrates, and the sealing member can be sandwiched between the pair of substrates.

[0141] The photoelectric conversion module of the present invention can be applied to a power supply device by combining it with a circuit board that controls the generated current. Examples of devices that use a power supply device include electronic desk calculators and wristwatches. In addition, a power supply device having the photoelectric conversion module of the present invention can be applied to mobile phones, electronic notebooks, electronic paper, and the like. In addition, a power supply device having the photoelectric conversion module of the present invention can be used as an auxiliary power source for extending the continuous use time of rechargeable or battery-powered electrical appliances, or as a power source that can be used at night by combining it with a secondary battery, etc. Furthermore, it can be used in IoT devices, artificial satellites, and the like as an independent power source that does not require battery replacement or power wiring, etc.

[0142] (electronic equipment) An electronic device of the present invention comprises the photoelectric conversion module of the present invention, and a device that operates on power generated by photoelectric conversion by the photoelectric conversion module, and further comprises other devices as necessary.

[0143] (Power supply module) The power supply module of the present invention includes the photoelectric conversion module of the present invention and a power supply IC (Integrated Circuit), and may further include other devices as necessary.

[0144] Next, a specific embodiment of an electronic device including a photoelectric conversion module of the present invention and a device that operates using the electric power generated by the photoelectric conversion module will be described.

[0145] FIG. 5 is a block diagram of a mouse for a personal computer as an example of the electronic device of the present invention. As shown in Figure 5, a photoelectric conversion module is combined with a power supply IC and a power storage device, and the supplied power is connected to the power supply of the mouse's control circuit. This allows the mouse to be operated using the power stored in the power storage device, which charges the mouse when it is not in use, eliminating the need for wiring or battery replacement. Eliminating the need for batteries also makes the mouse more lightweight, which is another advantage.

[0146] FIG. 6 is a schematic external view showing an example of the mouse shown in FIG. As shown in Figure 6, the photoelectric conversion module, power supply IC, and power storage device are mounted inside the mouse, but the upper part of the photoelectric conversion element of the photoelectric conversion module is covered with a transparent case so that light can hit the photoelectric conversion element. It is also possible to mold the entire mouse case from transparent resin. The arrangement of the photoelectric conversion element is not limited to this, and it is possible and preferable to arrange it in a position where light is irradiated even when the mouse is covered with the hand.

[0147] Next, another embodiment of an electronic device including a photoelectric conversion module of the present invention and a device that operates using the power generated by the photoelectric conversion module will be described.

[0148] FIG. 7 is a block diagram of a keyboard for a personal computer as an example of the electronic device of the present invention. As shown in Figure 7, the photoelectric conversion element of the photoelectric conversion module is combined with a power supply IC and a power storage device, and the supplied power is connected to the power supply of the keyboard's control circuit. This allows the power storage device to be charged when the keyboard is not in use, and the keyboard to operate using that power, resulting in a keyboard that does not require wiring or battery replacement. Eliminating the need for batteries also makes it possible to reduce the keyboard's weight, which is another advantage.

[0149] FIG. 8 is a schematic external view showing an example of the keyboard shown in FIG. As shown in Figure 8, the photoelectric conversion element, power supply IC, and power storage device of the photoelectric conversion module are mounted inside the keyboard, but the top of the photoelectric conversion element is covered with a transparent case so that light can reach the photoelectric conversion element. It is also possible to mold the entire keyboard case from transparent resin. The arrangement of the photoelectric conversion element is not limited to this. In the case of small keyboards where the space to incorporate the photoelectric conversion element is small, it is also possible and effective to embed a small photoelectric conversion element in part of the key, as shown in Figure 9.

[0150] Next, another embodiment of an electronic device including a photoelectric conversion module of the present invention and a device that operates using the power generated by the photoelectric conversion module will be described.

[0151] FIG. 10 is a block diagram of a sensor as an example of an electronic device of the present invention. As shown in Figure 10, the photoelectric conversion element of the photoelectric conversion module is combined with a power supply IC and a power storage device, and the supplied power is connected to the power supply of the sensor circuit. This makes it possible to configure a sensor module without the need to connect to an external power supply or replace batteries. This is effective as it can be applied to a variety of sensors for sensing objects such as temperature and humidity, illuminance, human presence, CO2, acceleration, UV, noise, geomagnetism, and air pressure. As shown in Figure 11, the sensor module is configured to periodically sense the object to be measured and transmit the read data to a PC, smartphone, etc. via wireless communication. With the advent of the IoT (Internet of Things) society, the number of sensors is expected to rapidly increase. Replacing the batteries in these countless sensors one by one is a huge effort and is not realistic. In addition, the sensors are located in places where it is difficult to replace the batteries, such as on ceilings and walls, which makes the work difficult. The fact that power can be supplied by photoelectric conversion elements is also a great advantage. In addition, the photoelectric conversion module of the present invention can obtain high output even at low illuminance, and has a small dependency on the light incident angle of the output, so it has the advantage of being highly flexible in installation.

[0152] Next, another embodiment of an electronic device including a photoelectric conversion module of the present invention and a device that operates using the power generated by the photoelectric conversion module will be described.

[0153] FIG. 11 is a block diagram of a turntable as an example of an electronic device of the present invention. As shown in Figure 11, a photoelectric conversion element, a power supply IC, and a power storage device are combined, and the supplied power is connected to the power supply of the turntable circuit. This makes it possible to configure a turntable without the need to connect to an external power supply or replace batteries. Turntables are used, for example, in showcases for displaying products, but the wiring for the power supply is unsightly, and the display items must be removed when changing the batteries, which is a lot of work. By using the photoelectric conversion module of the present invention, such problems can be effectively eliminated.

[0154] The above describes the photoelectric conversion module of the present invention, and the electronic device and power supply module having devices that operate using the electricity generated by these modules. However, these are only a small part of the applications, and the photoelectric conversion module of the present invention is not limited to these applications.

[0155] <Application> The photoelectric conversion element and photoelectric conversion module of the present invention can function as an independent power source, and can operate a device using the power generated by photoelectric conversion. The photoelectric conversion module of the present invention can generate power by being irradiated with light, so there is no need to connect the electronic device to a power source or replace the battery. Therefore, it is possible to operate the electronic device even in places where there is no power supply equipment, to carry it around on one's body, and to operate the electronic device without replacing the battery even in places where it is difficult to replace the battery. In addition, when dry batteries are used, the electronic device becomes heavy and large in size, which can cause problems in installation on a wall or ceiling or in carrying it around, but the photoelectric conversion module of the present invention is lightweight and thin, so it has a high degree of freedom in installation and is advantageous in terms of wearing it or carrying it around.

[0156] In this way, the photoelectric conversion element and photoelectric conversion module of the present invention can be used as a standalone power source and can be combined with various electronic devices, such as display devices such as electronic desk calculators, wristwatches, mobile phones, electronic notebooks, and electronic paper, computer accessories such as mice and keyboards, various sensor devices such as temperature and humidity sensors and human sensors, transmitters such as beacons and GPS, auxiliary lights, and remote controls.

[0157] The photoelectric conversion element and photoelectric conversion module of the present invention can generate electricity even under light with low illuminance, and can generate electricity indoors and even in dim shadows, and thus have a wide range of applications. In addition, they are highly safe, as they do not leak like dry batteries and cannot be swallowed like button batteries. Furthermore, they can be used as auxiliary power sources to extend the continuous use time of rechargeable or dry battery-powered electrical appliances. In this way, by combining the photoelectric conversion module of the present invention with a device that operates using the power generated by the photoelectric conversion, it is possible to transform the electronic device into one that is lightweight, easy to use, has a high degree of freedom in installation, does not require replacement, is safe, and is effective in reducing the environmental load.

[0158] The basic configuration diagram of an electronic device that combines the photoelectric conversion module of the present invention with a device that operates on the power generated by the photoelectric conversion is shown in Figure 12. When the photoelectric conversion element is irradiated with light, it generates power and can extract the power. The device circuit can then operate using that power.

[0159] However, since the output of the photoelectric conversion element in the photoelectric conversion module changes depending on the surrounding illuminance, the electronic device shown in Fig. 12 may not be able to operate stably. In this case, it is possible and effective to incorporate a power supply IC for the photoelectric conversion element between the photoelectric conversion element and the device circuit to supply a stable voltage to the circuit side, as shown in Fig. 13. However, while the photoelectric conversion element of a photoelectric conversion module can generate power if it is irradiated with light of sufficient illuminance, if the illuminance is insufficient to generate power, the desired power cannot be obtained, which is also a drawback of the photoelectric conversion element. In this case, as shown in Figure 14, by mounting a power storage device such as a capacitor between the power supply IC and the equipment circuit, it becomes possible to charge the power storage device with the surplus power from the photoelectric conversion element, and even if the illuminance is too low or no light hits the photoelectric conversion element, it becomes possible to supply the power stored in the power storage device to the equipment circuit, enabling stable operation.

[0160] In this way, in an electronic device that combines the photoelectric conversion module of the present invention with an equipment circuit, by combining a power supply IC and a power storage device, it becomes possible to operate in an environment without a power source, and it becomes possible to operate stably without the need for battery replacement, thereby making the most of the benefits of the photoelectric conversion element.

[0161] On the other hand, the photoelectric conversion module of the present invention can also be used as a power supply module, and is therefore useful. For example, as shown in Fig. 15, when the photoelectric conversion module of the present invention is connected to a power supply IC for a photoelectric conversion element, a DC power supply module can be configured that can supply the power generated by the photoelectric conversion of the photoelectric conversion element of the photoelectric conversion module at a constant voltage level using the power supply IC. Furthermore, as shown in Figure 16, by adding a power storage device to the power supply IC, it becomes possible to charge the power generated by the photoelectric conversion element of the photoelectric conversion module into the power storage device, making it possible to configure a power supply module that can supply power even when the illuminance is too low or when no light hits the photoelectric conversion element. The power supply module of the present invention shown in Figs. 15 and 16 can be used as a power supply module without the need for battery replacement as with conventional primary batteries. EXAMPLES

[0162] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0163] Example 1 <Fabrication of photoelectric conversion element> On a glass substrate as a first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) were successively formed as a first electrode by sputtering. Next, a dense layer (average thickness 20 nm) made of titanium oxide was formed as a hole blocking layer by reactive sputtering using oxygen gas.

[0164] Next, a titanium oxide (Greatcell Solar Materials, 18NR-T) paste was applied onto the hole blocking layer to an average thickness of approximately 1.2 μm, dried at 120°C, and then fired in air at 500°C for 30 minutes to form a porous electron transport layer. The glass substrate on which the electron transport layer was formed was immersed in a stirred solution of the photosensitizer compound represented by "B1-10" above (0.2 mM) and the photosensitizer compound represented by "B2-1" above (0.2 mM) in a mixture of acetonitrile / t-butanol (volume ratio 1:1), and left to stand in a dark place for 1 hour to allow the photosensitizer compound to be adsorbed onto the surface of the electron transport layer.

[0165] A hole transport layer coating solution was prepared by adding and dissolving 150 mM of the organic hole transport material represented by the above "D-7" (SHT-263, manufactured by Merck Ltd.), 70 mM of the lithium salt of lithium bis(trifluoromethanesulfonyl)imide (manufactured by Kishida Chemical Co., Ltd.), 135 mM of the basic compound represented by the above "H-1", and 15 mM of the cobalt complex represented by the above "F-11" (FK209, Greatcell solar materials) to 1 mL of a chlorobenzene solution.

[0166] Next, a hole transport layer with an average thickness of 500 nm was formed on the electron transport layer with the photosensitizing compound adsorbed thereon by a die coating method using a hole transport layer coating solution. After that, the edge of the glass substrate on which the sealing member was to be provided was etched by laser processing, and a through hole for connecting to the ITO layer, which would become the terminal extraction portion, was further formed by laser processing. Furthermore, silver was vacuum-deposited on the hole transport layer to form a second electrode with a thickness of about 70 nm.

[0167] Next, an ultraviolet curing resin (TB3118, manufactured by ThreeBond Holdings Co., Ltd.) was applied to the edge of the glass substrate using a dispenser (2300N, manufactured by Sanei Tech Co., Ltd.) so that the power generation region was surrounded. After that, the substrate was moved into a glove box with a dew point of minus 40°C and an oxygen concentration of 10%, and a cover glass was placed on the ultraviolet curing resin as a second substrate. After curing by ultraviolet irradiation, the substrate was heated at 80°C for 60 minutes. The power generation region was sealed, and the photoelectric conversion element of Example 1 as shown in FIG. 1 was produced.

[0168] (Examples 2 to 15) Photoelectric conversion elements of Examples 2 to 15 as shown in FIG. 1 were prepared in the same manner as in Example 1, except that the photosensitizer compounds "B1-10" and "B2-1" in Example 1 were changed to the materials shown in Table 1.

[0169] Example 16 A photoelectric conversion element as shown in FIG. 1 was prepared in the same manner as in Example 2, except that the basic compound represented by "H-1" in Example 2 was changed to 4-dimethylaminopyridine (DMAP) (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0170] (Example 17) A photoelectric conversion element as shown in FIG. 1 was prepared in the same manner as in Example 2, except that the basic compound represented by "H-1" in Example 2 was changed to 4-pyrrolidinopyridine (PYP) (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0171] (Example 18) A photoelectric conversion element as shown in FIG. 1 was prepared in the same manner as in Example 2, except that the basic compound represented by "H-1" in Example 2 was changed to 4-piperidinopyridine (PPP) (manufactured by Aldrich).

[0172] (Example 19) A photoelectric conversion element as shown in FIG. 1 was prepared in the same manner as in Example 9, except that in Example 2, the basic compound represented by "H-1" was changed to the basic compound represented by "H-3".

[0173] Comparative Example 1 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 2, except that in Example 2, the photosensitizer compound "B2-1" was changed to D102 (manufactured by Mitsubishi Paper Mills, Ltd.).

[0174] Comparative Example 2 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 1, except that in Example 1, the photosensitizer compound "B2-1" was changed to D358 (manufactured by Mitsubishi Paper Mills, Ltd.).

[0175] Comparative Example 3 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 2, except that in Example 2, the photosensitizer compound "B1-10" was changed to D102 (manufactured by Mitsubishi Paper Mills, Ltd.).

[0176] Comparative Example 4 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 2, except that in Example 2, the photosensitizer compound "B1-10" was changed to D358 (manufactured by Mitsubishi Paper Mills, Ltd.).

[0177] Comparative Example 5 A photoelectric conversion element as shown in FIG. 1 was prepared in the same manner as in Example 1, except that the photosensitizer compound "B2-1" in Example 1 was changed to 4-heptyloxybenzoic acid (HeBA) (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0178] Comparative Example 6 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 1, except that "B2-1" was not added as the dye.

[0179] Comparative Example 7 A photoelectric conversion element as shown in FIG. 1 was produced in the same manner as in Example 2, except that "B1-10" was not added as the dye.

[0180] Next, various characteristics of each of the obtained photoelectric conversion elements were evaluated as follows. The results are shown in Tables 1 to 3.

[0181] <Evaluation of photoelectric conversion elements> The IV characteristics of each photoelectric conversion element obtained were evaluated using a solar cell evaluation system (As-510-PV03, manufactured by NF Corporation) under irradiation of a 5000K white LED adjusted to 500 lux, and the initial open circuit voltage Voc1 (V) and maximum output power Pmax1 (μW / cm 2 ) was sought. The device was irradiated with a 5,000K white LED at 2,000 lux, 50°C, and 1,000 hours, and the IV characteristics were evaluated again under the same light source conditions. The open circuit voltage Voc2 and maximum output power Pmax2 (μW / cm2) after irradiation with high-intensity light were measured. 2 ) was measured, and the Voc maintenance rate (Voc2 / Voc1) (%) and Pmax maintenance rate (Pmax2 / Pmax1) (%) were calculated.

[0182] [Table 1]

[0183] [Table 2]

[0184] From the results of Tables 1 and 2, it was found that Examples 1 to 19 were able to suppress the deterioration of characteristics under low illuminance light after exposure to high-temperature light irradiation compared with Comparative Examples 1 to 7. It was found that in a solid-state dye-sensitized solar cell, the association state and interaction between dyes are very important for efficient photoelectric conversion under a high-temperature light irradiation environment.

[0185] For example, aspects of the present invention are as follows. <1> A photoelectric conversion element having a first electrode, an electron transport layer, a photosensitizing compound, a hole transport layer, and a second electrode, The photoelectric conversion element is characterized in that the photosensitizing compound contains a compound represented by the following general formula (1) and a compound represented by the following general formula (2). [ka] In the general formula (1), Ar1 and Ar2 each represent an aryl group which may have a substituent. R1 and R2 each represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents any of the substituents represented by the following structural formulas. [ka] [ka] In the general formula (2), R3 represents an aryl group or any of the substituents represented by the following structural formulas: n represents an integer of 0 to 1. [ka] <2> The electron transport layer is porous and made of titanium oxide particles carrying the photosensitizing compound. <1> The photoelectric conversion element according to the present invention is <3> The compound represented by the general formula (1) is a compound represented by the following general formula (3): <1> from <2> The photoelectric conversion element according to any one of the above items. [ka] In the general formula (3), Ar4 and Ar5 each represent a phenyl group which may have a substituent, or a naphthyl group which may have a substituent, and Ar6 represents a phenyl group or a thiophene group. <4> The hole transport layer contains a trivalent cobalt complex compound represented by the following general formula (4): <1> from <3> The photoelectric conversion element according to any one of the above items. [ka] In the general formula (4), R3 to R5 each represent a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group. Y represents a group represented by the following structural formula: 1 )from( 4 ) indicates one of the following: [ka] <5> The hole transport layer contains a basic compound represented by the following general formula (5): <1> from <4> The photoelectric conversion element according to any one of the above items. [ka] In the general formula (5), Ar7 and Ar8 each represent an aryl group which may have a substituent. <6> The hole transport layer contains a spiro compound. <1> from <5> The photoelectric conversion element according to any one of the above items. <7> The spiro compound is a compound having the following general formula (6): <6> The photoelectric conversion element according to the present invention is [ka] In the general formula (6), R4 to R7 each independently represent a substituted amino group such as a dimethylamino group, a diphenylamino group, or a naphthyl-4-tolylamino group. <8> The above <1> from <7> The present invention relates to an electronic device comprising a device that operates using electric power generated by photoelectric conversion using the photoelectric conversion element according to any one of the above. <9> The above <1> from <7> A photoelectric conversion element according to any one of the preceding claims, A power supply IC, The power supply module is characterized by having:

[0186] The above <1> from <7> The photoelectric conversion element according to any one of the <8> The electronic device according to the <9> The power supply module described in the above is capable of solving the above-mentioned problems in the prior art and achieving the object of the present invention. [Explanation of symbols]

[0187] 1 First Substrate 2 First electrode 3. Hole blocking layer 4 Electron transport layer 5. Photosensitizing Compounds 6. Hole transport layer 7 Second electrode 8 Sealing member 9 Second Board 10 Hollow part 101 Photoelectric conversion element [Prior art documents] [Patent documents]

[0188] [Patent Document 1] JP 2018-113305 A

Claims

1. A photoelectric conversion element having a first electrode, an electron transport layer, a photosensitizing compound, a hole transport layer, and a second electrode, The photoelectric conversion element, wherein the photosensitizing compound contains a compound represented by the following general formula (1) and a compound represented by the following general formula (2): 【Chemistry 1】 In the general formula (1), Ar １ and Ar ２ R represents an aryl group which may have a substituent. １ and R ２ represents a linear or branched alkyl group having 4 to 10 carbon atoms, and X represents any of the substituents represented by the following structural formulas: 【Chemistry 2】 【Chemistry 3】 In the above general formula (2), R ３ represents an aryl group or any of the substituents represented by the following structural formulas: n represents an integer of 0 to 1. 【Chemistry 4】

2. 2. The photoelectric conversion element according to claim 1, wherein the electron transport layer is porous and made of titanium oxide particles carrying the photosensitizing compound.

3. 3. The photoelectric conversion element according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3): 【Chemistry 5】 In the general formula (3), Ar ４ and Ar ５ represents a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. ６ represents a phenyl group or a thiophene group.

4. 4. The photoelectric conversion element according to claim 1, wherein the hole transport layer contains a trivalent cobalt complex compound represented by the following general formula (4): 【Chemistry 6】 In the above general formula (4), R ３ ~R ５ represents a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group, and Y represents any one of the following structural formulas (1) to (4). 【Chemistry 7】

5. The photoelectric conversion element according to claim 1 , wherein the hole transport layer contains a basic compound represented by the following general formula (5): 【Chemistry 8】 In the general formula (5), Ar ７ and Ar ８ represents an aryl group which may have a substituent.

6. The photoelectric conversion element according to claim 1 , wherein the hole transport layer contains a spiro compound.

7. The photoelectric conversion element according to claim 6 , wherein the spiro compound is a compound represented by the following general formula (6): 【Chemistry 9】 In the general formula (6), R ４ From R ７ each independently represents a substituted amino group such as a dimethylamino group, a diphenylamino group, or a naphthyl-4-tolylamino group.

8. 8. An electronic device comprising a device that operates on power generated by photoelectric conversion of the photoelectric conversion element according to claim 1.

9. The photoelectric conversion element according to claim 1 , A power supply IC; A power supply module comprising:

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