Photoelectric conversion element, photoelectric conversion module, electronic device, and power supply module

Abstract

To provide a photoelectric conversion element which provides high output even with low-intensity light and is excellent in persistence of that effect.SOLUTION: A photoelectric conversion element 101 has a first electrode 2, a photoelectric conversion layer, and a second electrode 7. The photoelectric conversion layer comprises an electron transport layer 4 and a hole transport layer 6. The photoelectric conversion layer contains: a photosensitizing compound represented by at least one of the general formula (1) in the figure and a specific formula; and a lithium salt represented by another specific formula.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element, a photoelectric conversion module, 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 much 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 or organic solar cells are known as indoor photoelectric conversion elements. Among organic solar cells, dye-sensitized solar cells are advantageous in that they are easily fabricated because they are composed of layers with separate charge generation and charge transport functions. In general, dye-sensitized solar cells have problems such as volatilization and leakage of electrolyte because they contain an 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, in order to provide a photoelectric conversion element that is highly efficient and has high long-term stability, for example, a photoelectric conversion element has been proposed that has a first electrode, an electron transport layer formed on the first electrode, a hole transport layer, and a second electrode, in which the electron transport layer contains an electron transport compound carrying a compound represented by the following general formula (1) and a compound represented by the following general formula (2) (for example, see Patent Document 1).

[0005] [ka] (In the formula, X1 and X2 represent an oxygen atom, a sulfur atom, or a selenium atom, R1 represents a methine group, R2 represents an alkyl group, an aryl group, or a heterocyclic group, R3 represents an acidic group which may be the same or different, m represents 1 or 2, and Z1 and Z2 represent groups which form a cyclic structure.)

[0006] [ka] (In the formula, R4 represents an aryl group or a heterocyclic group, and R5 represents an alkyl group, an alkoxy group, an alkenyl group, an alkylthio group, or an aryl ether group.) Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a photoelectric conversion element which can obtain a high output even under light of low illuminance and has excellent durability of the effect. [Means for solving the problem]

[0008] 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, a photoelectric conversion layer, and a second electrode, the photoelectric conversion layer including an electron transport layer and a hole transport layer, and the photoelectric conversion layer contains a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3). [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 above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent, or any of the substituents represented by the following structural formulas. [ka] [ka] In the general formula (3), A and B represent any one of the substituents F, CF3, C2F5, C3F7, and C4F9, and the substituents A and B are different. Effect of the Invention

[0009] According to the present invention, it is possible to provide a photoelectric conversion element which can obtain a high output even under light of low illuminance and has excellent durability of the effect. [Brief description of the drawings]

[0010] [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

[0011] (Photoelectric conversion element) 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. This photoelectric conversion element has a first electrode, a photoelectric conversion layer, and a second electrode, and the photoelectric conversion layer includes an electron transport layer and a hole transport layer, and may further have other members such as a first substrate, a second substrate, a hole blocking layer, and a sealing member, as necessary.

[0012] In the prior art, dyes related to photosensitizing compounds represented by the following general formula (1) have been disclosed, but there is no mention of lithium salts represented by the following general formula (3), and there is a problem in that the durability of output characteristics is insufficient.

[0013] In the present invention, there is provided a photoelectric conversion element having a first electrode, a photoelectric conversion layer, and a second electrode, the photoelectric conversion layer including an electron transport layer and a hole transport layer, and the photoelectric conversion layer contains a photosensitizing compound represented by at least one of the following general formulas (1) and (2), and a lithium salt represented by the following general formula (3), thereby providing a photoelectric conversion element that can obtain a high output even under light with low illuminance and has excellent durability of its effect.

[0014] [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.

[0015] [ka]

[0016] [ka] In the above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent, or any of the substituents represented by the following structural formulas.

[0017] [ka]

[0018] [ka] In the general formula (3), A and B represent any one of the substituents F, CF3, C2F5, C3F7, and C4F9, and the substituents A and B are different.

[0019] <First board> 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 as described below, a substrate having heat resistance to the firing temperature is preferred. In addition, the first substrate is preferably flexible. The substrate may be provided on either or both of the outermost portion on the first electrode side and the outermost portion on the second electrode side of the photoelectric conversion element. Hereinafter, the substrate provided on the outermost side of the first electrode will be referred to as the first substrate, and the substrate provided on the outermost side of the second electrode will be referred to as the second substrate.

[0020] <First electrode> The shape and size of the first electrode are not particularly limited and 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. 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. 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. 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 on the first substrate in advance 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 such as a mesh or stripe that allows light to pass through. 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 with the substrate by, for example, deposition, sputtering, or pressure bonding, and then providing a layer of ITO or FTO thereon.

[0021] <Photoelectric conversion layer> The photoelectric conversion layer is formed for the purpose of converting light irradiated to a photoelectric conversion element into electricity. Specifically, photoelectric conversion is performed by absorbing light irradiated to the photoelectric conversion element and transporting the generated electrons and holes to the first electrode or the second electrode. Therefore, the photoelectric conversion layer may include an electron transport layer for transporting electrons, a photosensitizing compound for absorbing light and generating charges, a hole transport layer for transporting holes, etc., and these layers may be stacked.

[0022] <<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 a hole blocking layer described later. For this reason, the electron transport layer 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. 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 particles constituting the porous electron transport layer. 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, it is advantageous in that a high dielectric constant and high mobility result in a high fill factor. The above semiconductor materials 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. 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 within the preferred range, 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, which is advantageous in that the loss due to recombination of charges can be reduced.

[0023] 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. As the wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used. 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. 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. These may be used alone or in combination of two or more.

[0024] 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. In order to improve film-forming properties, the addition of a thickener is also an effective means. Examples of thickeners include polyethylene glycol, polyvinyl alcohol, and ethyl cellulose. After the semiconductor material is applied, the semiconductor material particles may be brought into electronic contact with each other, and the film may 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 may be performed alone or in combination of two or more.

[0025] 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. 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. 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.

[0026] <<Photosensitizing Compounds>> In order to further improve the output and photoelectric conversion efficiency, the photosensitizing compound is adsorbed onto the surface of the semiconductor material constituting the electron transport layer. The photosensitizing compound is not particularly limited as long as it is a compound that is photoexcited by light irradiated to a photoelectric conversion element, and can be appropriately selected depending on the purpose, and contains at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2). These may contain either or both of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0027] [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.

[0028] [ka]

[0029] [ka] In the above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent, or any of the substituents represented by the following structural formulas.

[0030] [ka]

[0031] Among the photosensitizing compounds represented by the above general formula (1), the compound represented by the following general formula (4) is more preferably used because it can provide a high output even with low illuminance light.

[0032] [ka] In the general formula (4), 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 which may have a substituent, or a thiophene group which may have a substituent.

[0033] Specific examples of the photosensitizing compounds represented by the above general formula (1) and general formula (4) are shown below, but the present invention is not limited to these.

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] Among the photosensitizing compounds represented by the above general formula (2), the compound represented by the following general formula (5) is more preferably used because it can provide a high output even with low illuminance light.

[0040] [ka] In the above general formula (5), n represents an integer of 0 or 1.

[0041] Specific examples of the photosensitizing compounds represented by the above general formula (2) and general formula (5) are shown below, but the present invention is not limited to these.

[0042] [ka]

[0043] [ka]

[0044] These photosensitizing compounds may contain only one type, or two or more types. LED light sources are used with different colors such as warm, cool, and white, and it is known that the spectrum varies depending on the color. For example, a color temperature of 3,000K relatively strengthens the 600 nm region, resulting in a reddish bulb color, a color temperature of 5,000K results in a well-balanced daylight color overall, and a color temperature of over 6,500K relatively strengthens the 450 nm region, resulting in a bluish daylight color. Therefore, it is preferable to be able to maintain high output even if the color temperature of the LED used is different.

[0045] The photosensitizer compound used in the present invention has an absorption spectrum that is highly matched to the wavelength spectrum of LED, and can obtain high output with LED light. In particular, the absorption spectrum of the photosensitizer compound represented by the above general formula (1) has high absorbance and a wide absorption range, and is effective in maintaining high output even when the color temperature changes. In addition, it is highly matched to the LED light source with a color temperature of 5,000K, which is widely used in general, and therefore it is possible to obtain high output. In addition, by appropriately mixing the photosensitizer compound, it is possible to further improve the matching with the LED light source, which is effective. Furthermore, the color of the photoelectric conversion element itself is mostly reflected by the color of the photosensitizer compound, and mixing the photosensitizer compound is also effective in adjusting this color.

[0046] The method of adsorbing the photosensitizing compound on the surface of the semiconductor material of the electron transport layer can be a method of immersing the electron transport layer containing the semiconductor material in a solution or a dispersion of the photosensitizing compound, a method of applying the solution or the dispersion of the photosensitizing compound to the electron transport layer to adsorb the same, etc. When the electron transport layer on which the semiconductor material is formed is immersed in a solution or a dispersion of the photosensitizing compound, the immersion method, the dip method, the roller method, the air knife method, etc. can be used. In the case of a method in which a solution or a dispersion of a photosensitizing compound is applied to the electron transport layer to cause adsorption, a wire bar method, a slide hopper method, an extrusion method, a curtain method, a spin method, a spray method, etc. may be used. In addition, adsorption may also be performed in a supercritical fluid using carbon dioxide or the like. 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. 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.

[0047] Since some photosensitizing compounds work more effectively when their aggregation is suppressed, they may be used in combination with an agglutinating / dissociating agent, such as steroid compounds such as cholic acid and chenodeoxycholic acid, long-chain alkyl carboxylic acids, or long-chain alkyl phosphonic acids. The content of the disaggregating agent is preferably 0.5 to 100 parts by mole, more preferably 10 to 50 parts by mole, per 1 part by mole of the photosensitizing compound. The temperature when the photosensitizer compound, or the photosensitizer compound and the disaggregation 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.

[0048] <<Hole transport layer>> The hole transport layer may be made of any known material as long as it has a function of transporting holes, and examples of such materials include 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.

[0049] In the present invention, the hole transport layer contains a lithium salt represented by the following general formula (3).

[0050] [ka] In the general formula (3), A and B represent any one of the substituents F, CF3, C2F5, C3F7, and C4F9, and the substituents A and B are different.

[0051] Examples of these lithium salts include lithium (fluorosulfonyl) (trifluoromethanesulfonyl) imide (Li-FTFSI), lithium (fluorosulfonyl) (pentafluoroethanesulfonyl) imide (Li-FPFSI), lithium (fluorosulfonyl) (nonafluorobutanesulfonyl) imide (Li-FNFSI), lithium (nonafluorobutanesulfonyl) (trifluoromethanesulfonyl) imide (Li-NFTFSI), lithium (pentafluoroethanesulfonyl) (trifluoromethanesulfonyl) imide (Li-PFTFSI), etc. Among these, lithium (fluorosulfonyl) (trifluoromethylsulfonyl) imide (Li-FTFSI) is particularly preferred. When the photoelectric conversion layer contains these lithium salts, it is possible to improve the output under low illuminance light and is very effective in extending the durability of the output. In addition, it is possible to obtain an effect of improving the high-temperature storage resistance. The lithium salt is characterized by being asymmetric, with different anion species A and B. The asymmetric anion species not only increases the solubility of the lithium salt and allows a larger amount to be contained, but also improves the compatibility of the lithium salt, improves the stability of the film, and suppresses the occurrence of crystallization, which is believed to be the reason for the above effects. The method of adding the lithium salt is preferably to add it to a hole transport layer forming coating liquid and apply it, but it is not necessarily required that the lithium salt is contained in the hole transport layer in the formed film, and it is included in the present invention as long as it is contained in the photoelectric conversion layer including the hole transport layer and the electron transport layer. In addition, even when the lithium salt is applied using a hole transport layer forming coating liquid containing the lithium salt, it is not necessary that the lithium salt is contained in the formed film in the form of lithium salt, and it may be contained in the form of lithium cations and anions separated. Specifically, it has been revealed that when the hole transport layer is formed in a state in which the lithium salt is contained in the hole transport layer forming coating liquid, the lithium cations migrate to the electron transport layer and are contained in greater amounts in the electron transport layer than in the hole transport layer. On the other hand, it has been revealed that the anions are partially migrated to the electron transport layer, but are contained in greater amounts in the hole transport layer than in the electron transport layer. In the present invention, it is preferable that the lithium salt is separated into cations and anions in this way, and each of them forms a different distribution state, and it is considered that the effect of the present invention can be obtained by containing them in the photoelectric conversion layer.

[0052] In addition to the lithium salt, it is also possible to include lithium salts having different structures.These lithium salts may be those having an anion species other than the above-mentioned lithium salts, such as lithium bis(fluorosulfonyl)imide (Li-FSI), lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), lithium bis(pentafluoroethanesulfonyl)imide (Li-BETI), lithium bis(nonafluorobutanesulfonyl)imide, etc.Also include cyclic imides such as lithium(cyclohexafluoropropane)(disulfone)imide.

[0053] The content of the lithium salt is preferably 5 mol % to 50 mol %, more preferably 20 mol % to 35 mol %, based on the hole transport material. By having the content within the above range, it is possible to achieve high output with respect to low illuminance light, improved output retention, and high durability.

[0054] The hole transport layer contains a hole transport material or a P-type semiconductor material to obtain a 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 preferred.

[0055] The spiro compound is preferably a compound represented by the following general formula (8). [ka] In the above general formula (8), R 31 ~R 34 each independently represents a substituted amino group such as a dimethylamino group, a diphenylamino group, or a naphthyl-4-tolylamino group.

[0056] Specific examples of the spiro compound include (D-1) to (D-20) shown below, but are not limited thereto.

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] 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, dissolving in various organic solvents, and because they are amorphous (amorphous substances without 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.

[0065] In addition to the hole transport material or the lithium salt, it is preferable to add an oxidizing agent to the hole transport layer, which improves hole transport properties and enhances durability and stability of 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 and hypervalent iodine compounds are preferably used. When the oxidizing agent is a metal complex or a hypervalent iodine compound, it has high solubility in organic solvents and can be added in large amounts, resulting in improved hole transportability and excellent durability of the effect.

[0066] A metal complex is composed of a metal cation, a ligand, and an anion. Examples of metal cations include cations of chromium, manganese, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, gold, platinum, etc. Among these, cations of cobalt, iron, nickel, and copper are preferred, and cobalt complexes are more preferred. The ligand is preferably one containing at least one nitrogen-containing 5- and / or 6-membered heterocycle, which may have a substituent. Specific examples include, but are not limited to, the following:

[0067] [ka]

[0068] [ka] TIFF0007651842000037.tif75140

[0069] 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.

[0070] 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.

[0071] [ka]

[0072] [ka]

[0073] More preferred is a trivalent cobalt complex represented by the following general formula (6). [ka] In the general formula (6), R4 to R6 each represent a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group, and X represents any one of the following structural formulae (1) to (4). [ka]

[0074] Preferable examples of these metal complexes include (F-1) to (F-20) shown below, but are not limited to these.

[0075] [ka]

[0076] [ka]

[0077] The content of the oxidizing agent is preferably 1 mol % to 30 mol %, more preferably 5 mol % to 20 mol %, based on the hole transport material. It is not necessary for the entire hole transport material to be oxidized by the addition of the oxidizing agent, and it is effective if only a portion of the hole transport material is oxidized. The oxidizing agent may be used alone or in combination of two or more kinds. By using two or more kinds in combination, the hole transport layer becomes less likely to crystallize, and high heat resistance can be obtained.

[0078] The hole transport layer preferably further contains a basic compound. By containing a basic compound, the open circuit voltage can be increased, which is effective in increasing the output. As the basic compound, any known material that exhibits basicity can be used, but a compound having a pyridine structure is particularly effective. A pyridine ring is represented by the following structural formula (6), and a compound having a pyridine structure is a compound that contains at least one pyridine ring.

[0079] [ka]

[0080] Among these compounds having a pyridine structure, basic compounds such as 4-dimethylaminopyridine (DMAP), 4-pyrrolidinopyridine (PYP), 4-piperidinopyridine (PPP), tertiary butylpyridine (TBP), etc. are preferably used. More preferably, the basic compound represented by the following general formula (7) is effective.

[0081] [ka] In the general formula (7), Ar7 and Ar8 each represent an aryl group which may have a substituent. Examples 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.

[0082] In addition to the above-mentioned effects, when the hole transport layer contains such a basic compound, the output stability of the photoelectric conversion element is improved, and in particular, the variation in the output characteristics for low illuminance light is reduced, which is advantageous in that stable power generation is possible.

[0083] Specific examples of the basic compound represented by the above general formula (7) are shown below, but the present invention is not limited to these.

[0084] [ka]

[0085] The content of the basic compound 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. By setting the content of the basic compound 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. The molar ratio A / B of the basic compound A to the lithium salt B is preferably less than 2.0, more preferably 1.8 or less, and even more preferably 1.7 or less. When the molar ratio A / B is less than 2.0, it becomes possible to maintain high output for a long period of time when irradiated with low-intensity light, and there is an advantage in that durability can be improved.

[0086] 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. The polymer material used for the hole transport layer may be any known hole transport polymer material.

[0087] Examples of the hole transporting polymeric material include polythiophene compounds, polyphenylenevinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiadiazole compounds. 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). 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)]. 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)]. Examples of the polyphenylene compound include poly[2,5-dioctyloxy-1,4-phenylene] and poly[2,5-di(2-ethylhexyloxy-1,4-phenylene]. 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. 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). Among these, polythiophene compounds and polyarylamine compounds are preferred from the viewpoints of carrier mobility and ionization potential.

[0088] 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 thickness on the electron 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 particularly preferably 0.2 μm or more and 2 μm or less. 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.

[0089] 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. Examples of supercritical fluids include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, and ether solvents. Examples of the alcohol solvent include methanol, ethanol, and n-butanol. Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene, etc. Examples of the halogen solvent include methylene chloride, chlorotrifluoromethane, etc. An example of the ether solvent is dimethyl ether. 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. 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. 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.

[0090] Furthermore, in addition to the supercritical fluid and the subcritical fluid, an organic solvent or 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. 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. Examples of ether solvents include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane. 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.

[0091] 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. 2 The 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.

[0092] 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, or 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.

[0093] <<Hole blocking layer>> In the present invention, it is possible to form a hole blocking layer, which is very effective in improving output and improving its durability. The hole blocking layer is formed between the first electrode and the electron transport layer. The hole blocking layer is generated by a photosensitizing compound, and transports electrons transported to the electron transport layer to the first electrode and can prevent contact with the hole transport layer. As a result, the hole blocking layer makes it difficult for holes to flow into the first electrode, and can suppress a decrease in output due to recombination of electrons and holes. A solid-type photoelectric conversion element provided with a hole transport layer has a faster recombination rate between holes in the hole transport material and electrons on the electrode surface than a wet-type element using an electrolyte, so the effect of forming a hole blocking layer is very large. 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.

[0094] 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, polycrystalline, or amorphous.

[0095] 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 a chemical reaction such as hydrolysis or polymerization / condensation, and then densification is promoted by a 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. 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.

[0096] <<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 the second substrate is not necessarily required as long as the strength is sufficient. 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.

[0097] The second electrode can be formed on the hole transport layer by a suitable method such as coating, laminating, vapor deposition, CVD, or lamination, depending on the type of material used or 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.

[0098] <<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.

[0099] <<Sealing member>> The photoelectric conversion element of the present invention can effectively use a sealing member capable of shielding at least the electron transport layer and the hole transport layer from the external environment of the photoelectric conversion element. The sealing member may be any conventionally known method that can reduce the intrusion of excess moisture or oxygen from the external environment into the sealed interior. The sealing member also has the effect of preventing mechanical damage caused by pressure from the outside, and any conventionally known method may be used as long as this effect can be realized. Sealing methods can be broadly divided into "frame sealing," in which a sealing member is provided around the periphery of the power generation area, which is made up of the photoelectric conversion layer of the photoelectric conversion element, and then bonded to the second substrate, and "surface sealing," in which a sealing member is provided over the entire surface of the power generation area and then bonded to the second substrate. The former, "frame sealing," can form a hollow space inside the seal, making it possible to properly adjust the amount of moisture or oxygen inside the seal, and since the second electrode is not in contact with the sealing member, it has the effect of reducing the effect of electrode peeling. On the other hand, the latter, "surface sealing," is excellent at preventing the intrusion of excess water or oxygen from the outside, and has a large adhesive area with the sealing member, so it has high sealing strength, and is particularly suitable when a flexible substrate is used for the first substrate.

[0100] The type of the sealing member is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include curable resins, low-melting glass resins, etc. The curable resin is not particularly limited as long as it is a resin that is cured by light or heat, and can be appropriately selected depending on the purpose, and among them, acrylic resins and epoxy resins are preferably used. As the cured acrylic resin, any known material can be used as long as it is obtained by curing 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 that the epoxy resin is mixed with a curing agent or various additives as necessary. 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.

[0101] 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 or 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 or oxygen, but also by the influence of outgassing generated during curing or heating of the sealing member. 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 in the sealing member, these themselves can suppress the intrusion of moisture or oxygen, and the amount of sealing member used can be reduced, resulting in an 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. 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, more preferably 1 μm or more and 5 μm or less. When the amount added is within the preferred range, the effect of suppressing the intrusion of moisture or oxygen can be sufficiently obtained, the viscosity becomes appropriate, and it is also effective in improving adhesion and defoaming with the substrate, or in controlling the width of the sealing part and 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 or oxygen is obtained, the viscosity is appropriate, and the adhesion and workability are also good.

[0102] The gap agent is also called a gap control agent or spacer agent, and enables the gap of the sealing part to be controlled. For example, when a sealing member is applied on a first substrate or a first electrode, and a second substrate is placed thereon 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, and therefore 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. The average 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.

[0103] 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 or 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, an alkylsulfonium salt, or the like is used as a thermal cationic polymerization initiator. On the other hand, a photo-cationic polymerization initiator is preferably used for 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 causing little volumetric shrinkage during curing, not being inhibited by oxygen, and having high storage stability. 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 ionic onium salts such as 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.

[0104] 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.

[0105] 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.

[0106] 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. 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 or 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.).

[0107] On the other hand, the low-melting glass resin is applied and then baked at about 550°C to decompose the resin components, and then melted by an infrared laser or the like while adhering to the glass substrate. At this time, the low-melting glass components diffuse into the metal oxide layer and are physically bonded, thereby obtaining high sealing performance. In addition, since the resin components are eliminated, outgassing, unlike acrylic resin or epoxy resin, is not generated, which is effective in preventing deterioration of the photoelectric conversion element. In addition, in the present invention, a sheet-shaped sealing material can be used. The sheet-shaped 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-shaped sealing material is attached to the second electrode 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, it is also possible to form a structure with a hollow portion, which is effective. If the resin layer formed on the sheet is formed on the entire surface, it becomes "surface sealing", but if the resin layer is patterned so as to provide a hollow portion inside the photoelectric conversion element depending on the formation pattern of the resin layer, it becomes "frame sealing".

[0108] 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.

[0109] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and duplicated explanations may be omitted. By containing oxygen in the hollow space inside the sealing, it becomes possible to stably maintain the hole transport function of the hole transport part for a long period of time, which is effective in improving the durability of the photoelectric conversion element. In the present invention, the oxygen concentration in the hollow space inside the sealing provided by sealing is preferably 5.0 volume % or more and 21.0 volume % or less, although the effect can be obtained as long as the hollow space contains oxygen. The oxygen concentration in the hollow portion can be controlled by sealing it in a glove box with an adjusted oxygen concentration. The oxygen concentration can be adjusted by using a gas cylinder with a specific oxygen concentration or a nitrogen gas generator. The oxygen concentration in the glove box is measured using a commercially available oxygen concentration meter or oxygen monitor. The oxygen concentration in the hollow portion formed by sealing can be measured, for example, by an atmospheric pressure ionization mass spectrometer (API-MS). Specifically, the photoelectric conversion element is placed in a chamber filled with an inert gas, the seal is removed in the chamber, and the gas in the chamber is quantitatively analyzed by API-MS to quantify all components in the gas contained in the hollow portion, and the ratio of oxygen to the sum of the components is calculated, thereby obtaining the oxygen concentration. The gas other than oxygen is preferably an inert gas, such as nitrogen or argon. When sealing, it is preferable to control the dew point as well as the oxygen concentration inside the glove box, which is effective in improving the output and durability. The dew point is defined as the temperature at which condensation begins when a gas containing water vapor is cooled. The dew point is not particularly limited, but is preferably 0° C. or lower, more preferably −20° C. or lower. The lower limit is preferably −50° C. or higher.

[0110] Hereinafter, 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.

[0111] <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 and 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.

[0112] <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.

[0113] <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 formed by applying the sealing member 8 to the entire surface of the second electrode 7 and providing a second substrate 9 thereon, or by using the above-mentioned sheet-like sealing material. 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.

[0114] <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 or oxygen.

[0115] (Photoelectric conversion module) In the photoelectric conversion module of the present invention, the photoelectric conversion elements of the present invention are electrically connected in series or in parallel. The photoelectric conversion 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 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 module may be the same as that of the photoelectric conversion element. The structure of the photoelectric conversion 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. Furthermore, the photoelectric conversion module may 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 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.

[0116] The photoelectric conversion module of the present invention can be applied to a power supply device by combining it with a circuit board or the like 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 also 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, a power source that can be used at night by combining it with a secondary battery, and the like. 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.

[0117] (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.

[0118] (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.

[0119] 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.

[0120] 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 power storage device to be charged when the mouse is not in use, and the mouse can be operated using that power, resulting in a mouse that does not require wiring or battery replacement. Eliminating the need for batteries also makes it possible to reduce the weight, which is an advantage.

[0121] 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 for example, it is also possible and preferable to arrange it in a position where light is irradiated even when the mouse is covered with the hand.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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 or smartphone 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] <Application> The 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, or 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.

[0131] In this way, the 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 presence sensors, transmitters such as beacons and GPS, auxiliary lights, and remote controls.

[0132] The photoelectric conversion module of the present invention can generate electricity even under low-illuminance light, and can generate electricity indoors and even in dimly lit shadows, making it applicable in a wide range of applications. In addition, it is highly safe, as it does not leak like dry batteries and cannot be swallowed like button batteries. Furthermore, it can be used as an auxiliary power source 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 on 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.

[0133] 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.

[0134] 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 electricity if it is irradiated with light of sufficient illuminance, if the illuminance is insufficient to generate electricity, 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 and 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.

[0135] 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 or a power storage device, it becomes possible to operate even in an environment without a power source, and it becomes possible to operate stably without the need for battery replacement, thereby making it possible to maximize the benefits of the photoelectric conversion element.

[0136] 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 and 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

[0137] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0138] Example 1 <Fabrication of photoelectric conversion module> Indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) were successively sputtered onto a glass substrate as the first substrate as the first electrode, and then a dense layer (average thickness 20 nm) made of titanium oxide was formed as a hole blocking layer by reactive sputtering using oxygen gas. Next, a titanium oxide (Greatcell Solar Materials, 18NR-T) paste was applied by screen printing onto the hole blocking layer to an average thickness of about 1.3 μm. After drying at 120°C, it was baked in air at 550°C for 30 minutes to form a porous electron transport layer. After that, the ITO / NTO layer, hole blocking layer, and electron transport layer were divided into eight cells by laser processing. The glass substrate on which the electron transport layer was formed was immersed in a stirred solution of the photosensitizing compound represented by B1-1 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 photosensitizing compound to be adsorbed onto the surface of the electron transport layer. Next, 70.2 mM of lithium bis(fluorosulfonyl)(trifluoromethanesulfonyl)imide (LiFTFSI) (Kishida Chemical Co., Ltd.) as lithium salt B, 145.8 mM of pyridine compound A represented by H-1 above, 162.0 mM of organic hole transport material (HTM) represented by D-7 above (SHT-263, Merck Co., Ltd.) and 12.6 mM of cobalt complex represented by F-11 above (Greatcell solar materials Co., Ltd.) were added and dissolved in the chlorobenzene solution to prepare a hole transport layer coating solution. The molar ratio A / B of pyridine compound A and lithium salt B was 2.08. Next, a hole transport layer of about 550 nm was formed by die coating on the electron transport layer with the photosensitizing compound adsorbed thereon 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 through holes for connecting to the ITO / NTO layer as the terminal extraction part were formed by laser processing, and through holes for connecting the cells in series were also formed by laser processing. After attaching a mask to the edge of the glass substrate and between the cells, silver was vacuum-deposited to form a second electrode having a thickness of about 70 nm. A UV-curable resin (WorldRock No. 5910, manufactured by Kyoritsu Chemical Industry 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. The glass was then moved into a glove box with a dew point adjusted to minus 40°C and a mixed gas of nitrogen and oxygen (oxygen concentration: 10% by volume) introduced, and a cover glass was placed on the UV-curable resin as a second substrate. After curing by UV irradiation, the resin was heated at 80°C for 60 minutes. As described above, the power generation region was sealed, and finally, a UV-cut film was attached to the light receiving surface to produce the photovoltaic conversion module 1 of the present invention shown in FIG. 3.

[0139] Example 2 Photoelectric conversion module 2 was produced in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above B1-2, the lithium salt was changed to lithium (fluorosulfonyl)(pentafluoroethanesulfonyl)imide (Li-FPFSI) 69.2 mM, the pyridine compound was changed to 143.8 mM, the organic hole transport material was changed to 159.8 mM, and the cobalt complex was changed to 12.5 mM.

[0140] Example 3 Photoelectric conversion module 3 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above B1-5, the lithium salt was changed to 73.2 mM, the pyridine compound was changed to 145.3 mM, the organic hole transport material was changed to 161.5 mM, and the cobalt complex was changed to 12.6 mM.

[0141] Example 4 Photoelectric conversion module 4 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above B1-9, the lithium salt was changed to 75.7 mM, the pyridine compound was changed to 146.1 mM, and the organic hole transport material was changed to 162.3 mM, and the cobalt complex was changed to 13.0 mM of the cobalt complex represented by the above F-19 (manufactured by Greatcell Solar Materials).

[0142] Example 5 Photoelectric conversion module 5 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above-mentioned B1-10, the lithium salt was changed to 80.2 mM, the pyridine compound was changed to 144.3 mM, the organic hole transport material was changed to 160.4 mM, and the cobalt complex was changed to 12.5 mM.

[0143] Example 6 Photoelectric conversion module 6 was produced in the same manner as in Example 5, except that the lithium salt was changed to 85.1 mM, the pyridine compound to 143.7 mM, the organic hole transport material to 159.6 mM, and the cobalt complex to 12.5 mM.

[0144] Example 7 Photoelectric conversion module 7 was produced in the same manner as in Example 5, except that the lithium salt was changed to 90.0 mM, the pyridine compound to 142.9 mM, the organic hole transport material to 158.8 mM, and the cobalt complex to 12.4 mM.

[0145] Example 8 Photoelectric conversion module 8 was produced in the same manner as in Example 5, except that the lithium salt was changed to 94.8 mM, the pyridine compound to 142.3 mM, the organic hole transport material to 158.1 mM, and the cobalt complex to 12.3 mM.

[0146] Example 9 Photoelectric conversion module 8 was produced in the same manner as in Example 5, except that the lithium salt was changed to 99.6 mM, the pyridine compound to 141.6 mM, the organic hole transport material to 157.3 mM, and the cobalt complex to 12.3 mM.

[0147] Example 10 A photoelectric conversion module 10 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above-mentioned B2-2, the lithium salt was changed to 70.6 mM, the pyridine compound was changed to 144.5 mM, the organic hole transport material was changed to 160.5 mM, and the cobalt complex was changed to 13.9 mM.

[0148] Example 11 A photoelectric conversion module 11 was produced in the same manner as in Example 10, except that the lithium salt was changed to 84.4 mM, the pyridine compound to 142.5 mM, the organic hole transport material to 158.3 mM, and the cobalt complex to 13.7 mM.

[0149] Example 12 A photoelectric conversion module 12 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above-mentioned B2-1, the lithium salt was changed to 69.6 mM, the pyridine compound was changed to 144.6 mM, the organic hole transport material was changed to 160.7 mM, and the cobalt complex was changed to 13.9 mM.

[0150] (Example 13) A photoelectric conversion module 13 was produced in the same manner as in Example 12, except that the lithium salt was changed to 89.9 mM, the pyridine compound to 142.7 mM, the organic hole transport material to 158.6 mM, and the cobalt complex to 12.7 mM.

[0151] Example 14 A photoelectric conversion module 14 was prepared in the same manner as in Example 5, except that in Example 5, the lithium salt was changed to 81.8 mM of lithium (fluorosulfonyl) (nonafluorobutanesulfonyl) imide (Li-FNFSI), the pyridine compound was changed to 138.1 mM, the organic hole transport material was changed to 153.4 mM, and the cobalt complex was changed to 12.0 mM of the cobalt complex represented by F-19 (manufactured by Greatcell Solar Materials).

[0152] Example 15 Photoelectric conversion module 15 was prepared in the same manner as in Example 5, except that in Example 5, the lithium salt was changed to 90.6 mM of lithium (pentafluoroethanesulfonyl) (trifluoromethanesulfonyl) imide (Li-PFTFSI), the pyridine compound was changed to 135.9 mM of the pyridine compound represented by H-3 above, the organic hole transport material was changed to 151.0 mM, and the cobalt complex was changed to 11.8 mM.

[0153] Comparative Example 1 A photoelectric conversion module 16 of Comparative Example 1 was prepared in the same manner as in Example 1, except that in Example 1, no lithium salt was added, and the pyridine compound was changed to 145.8 mM, the organic hole transport material to 157.0 mM, and the cobalt complex to 12.6 mM.

[0154] Comparative Example 2 A photoelectric conversion module 17 of Comparative Example 2 was prepared in the same manner as in Example 1, except that in Example 1, the lithium salt was changed to 71.1 mM lithium bis(fluorosulfonyl)imide (Li-FSI), the pyridine compound was changed to 147.8 mM, the organic hole transport material was changed to 164.2 mM, and the cobalt complex was changed to 12.8 mM.

[0155] Comparative Example 3 Photoelectric conversion module 18 of Comparative Example 3 was prepared in the same manner as in Comparative Example 2, except that the lithium salt was changed to 83.7 mM lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), the pyridine compound was changed to 141.3 mM, the organic hole transport material was changed to 157.0 mM, and the cobalt complex was changed to 12.3 mM.

[0156] Comparative Example 4 A photoelectric conversion module 19 of Comparative Example 4 was prepared in the same manner as in Example 1, except that in Example 1, the photosensitizing compound was changed to the above-mentioned B2-1, the lithium salt was changed to 71.1 mM lithium bis(fluorosulfonyl)imide (Li-FSI), the pyridine compound was changed to 147.8 mM, the organic hole transport material was changed to 164.2 mM, and the cobalt complex was changed to 12.8 mM.

[0157] Comparative Example 5 The photoelectric conversion module 20 of Comparative Example 5 was prepared in the same manner as in Comparative Example 4, except that the lithium salt was changed to 83.7 mM lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), the pyridine compound was changed to 141.3 mM, the organic hole transport material was changed to 157.0 mM, and the cobalt complex was changed to 12.3 mM.

[0158] Next, for each of the produced photovoltaic conversion modules, the sealed oxygen concentration and the performance of the photovoltaic conversion module (initial maximum output power Pmax1 and Pmax maintenance rate) were evaluated as follows. The results are shown in Table 2.

[0159] <Sealed oxygen concentration> The oxygen concentration inside the sealed container can be measured by a conventional method. For example, there is a method of quantitatively analyzing the relative concentration of gas components inside the sealed container using a mass spectrometer, which is effectively used in the present invention. Specifically, the method involves opening the sealed portion of the sample under high vacuum and quantifying the moisture and gas that come out by mass spectrometry. Mass spectrometers include quadrupole types and time-of-flight types, with the latter being capable of more sensitive measurements.

[0160] <Performance evaluation of photoelectric conversion modules> The obtained photovoltaic conversion module was evaluated for its IV characteristics using a solar cell evaluation system (As-510-PV03, manufactured by NF Corporation) under irradiation of a 5,000K white LED adjusted to 200 lx, and the initial maximum output power Pmax1 (μW / cm 2 After that, the device was exposed to a 5,000K white LED adjusted to 10,000 lx for 1,000 hours, and then the IV characteristics were evaluated under a 5,000K white LED adjusted to 200 lx. The maximum output power Pmax2 (μW / cm2) after exposure to high-intensity light was then measured. 2 ) was measured, and the Pmax maintenance rate [(Pmax2 / Pmax1)×100] (%) was calculated.

[0161] [Table 1]

[0162] [Table 2]

[0163] From the results of Tables 1 and 2, it is possible to obtain high output even with low illuminance light in Examples 1 to 15 by using a photosensitizer compound represented by at least one of the general formula (1) and the general formula (2). It was also found that Examples 1 to 15 can maintain high output for a long period of time and have excellent durability by containing the lithium salt represented by the general formula (3). It is believed that the lithium salt represented by the general formula (3) has asymmetric anion species, which improves solubility and compatibility, and allows it to exist stably in the film even when the amount added is increased, which leads to improved durability.

[0164] For example, aspects of the present invention are as follows. <1> A photoelectric conversion element having a first electrode, a photoelectric conversion layer, and a second electrode, the photoelectric conversion layer includes an electron transport layer and a hole transport layer, The photoelectric conversion layer is a photoelectric conversion element characterized by containing a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2) and a lithium salt represented by the following general formula (3). [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 above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent, or any of the substituents represented by the following structural formulas. [ka] [ka] In the general formula (3), A and B represent any one of the substituents F, CF3, C2F5, C3F7, and C4F9, and the substituents A and B are different. <2> The photosensitizing compound represented by the general formula (1) is a compound represented by the following general formula (4): <1> The photoelectric conversion element according to the present invention is [ka] In the general formula (4), 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 which may have a substituent, or a thiophene group which may have a substituent. <3> The photosensitizing compound represented by the general formula (2) is a compound represented by the following general formula (5): <1> from <2> The photoelectric conversion element according to any one of the above items. [ka] In the above general formula (5), n represents an integer of 0 or 1. <4> The lithium salt represented by the general formula (3) is lithium (fluorosulfonyl) (trifluoromethanesulfonyl) imide. <1> from <3> The photoelectric conversion element according to any one of the above items. <5> The photoelectric conversion layer contains a trivalent cobalt complex represented by the following general formula (6): <1> from <4> The photoelectric conversion element according to any one of the above items. [ka] In the general formula (6), R4 to R6 each represent a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group, and X represents any one of the following structural formulae (1) to (4). [ka] <6> The hole transport layer contains a basic compound represented by the following general formula (7): <1> from <5> The photoelectric conversion element according to any one of the above items. [ka] In the general formula (7), Ar7 and Ar8 each represent an aryl group which may have a substituent. <7> the molar ratio A / B of the basic compound A to the lithium salt B is less than 2.0; <6> The photoelectric conversion element according to the present invention is <8> A hole blocking layer is provided between the first electrode and the photoelectric conversion layer. <1> from <7> The photoelectric conversion element according to any one of the above items. <9> The photoelectric conversion element further includes a sealing member that shields the photoelectric conversion layer from an external environment of the photoelectric conversion element. <1> from <8> The photoelectric conversion element according to any one of the above items. <10> The above <1> from <9> 1 is a photoelectric conversion module comprising the photoelectric conversion elements according to any one of claims 1 to 9 electrically connected in series or in parallel. <11> In a photoelectric conversion module having 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 penetrating at least the photoelectric conversion layer. <10> 2. The photoelectric conversion module according to claim 1 . <12> a sealing member that shields photoelectric conversion layers of the photoelectric conversion elements that constitute the photoelectric conversion module from an external environment of the photoelectric conversion module; <10> from <11> 13. The photoelectric conversion module according to claim 12, wherein <13> The above <1> from <12> and a device that operates using power generated by photoelectric conversion by at least one of the photoelectric conversion element and the photoelectric conversion module. <14> The above <1> from <12> The electronic device is characterized by having at least one of a photoelectric conversion element and a photoelectric conversion module described in any one of the above, a storage battery capable of storing electricity generated by photoelectric conversion of at least one of the photoelectric conversion element and the photoelectric conversion module, and a device that operates using the electricity stored in the storage battery. <15> The above <10> from <12> A photoelectric conversion module according to any one of the preceding claims, A power supply IC, The power supply module is characterized by having:

[0165] The above <1> from <9> The photoelectric conversion element according to any one of the <10> from <12> The photoelectric conversion module according to any one of the preceding claims. <13> from <14> The electronic device according to any one of the preceding claims, <15> 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]

[0166] 1 First Substrate 2, 2a, 2b First electrode 3. Hole blocking layer 4 Electron transport layer 5. Photosensitizing Compounds 6. Hole transport layer 7, 7a, 7b Second electrode 8 Sealing member 9 Second Board 10 Hollow part 11 Penetration (conductive part) 101 Photoelectric conversion element [Prior art documents] [Patent documents]

[0167] [Patent Document 1] JP 2018-113437 A

Claims

1. A photoelectric conversion element having a first electrode, a photoelectric conversion layer, and a second electrode, the photoelectric conversion layer includes an electron transport layer and a hole transport layer, The photoelectric conversion element, wherein the photoelectric conversion layer contains a photosensitizing compound represented by the following general formula (1) and a lithium salt represented by the following general formula (3). 【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 general formula (3), A and B are each independently F, CF ３ , C ２ F ５ , C ３ F ７ , and C ４ F ９ The substituents A and B are different from each other.

2. The photoelectric conversion element according to claim 1 , wherein the photoelectric conversion layer further contains a photosensitizing compound represented by the following general formula (2): 【Chemistry 4】 In the general formula (2), n represents an integer of 0 or 1. ３ represents an aryl group which may have a substituent, or any of the substituents represented by the following structural formulas: 【Chemistry 5】

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

4. 4. The photoelectric conversion element according to claim 1, wherein the lithium salt represented by the general formula (3) is lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide.

5. The photoelectric conversion element according to claim 1 , wherein the photoelectric conversion layer contains a trivalent cobalt complex represented by the following general formula (6): 【Chemistry 7】 In the general formula (6), R ４ From R ６ represents a hydrogen atom, a methyl group, an ethyl group, a tertiary butyl group, or a trifluoromethyl group, and X represents any one of the following structural formulas (1) to (4). 【Chemistry 8】

6. The hole transport layer contains a basic compound represented by the following general formula (7):

6. The photoelectric conversion element according to claim 1, wherein a molar ratio A / B of the basic compound A to the lithium salt B is less than 2.

0. 【Chemistry 9】 In the general formula (7), Ar ７ and Ar ８ represents an aryl group which may have a substituent.

7. The photoelectric conversion element according to claim 1 , further comprising a hole blocking layer between the first electrode and the photoelectric conversion layer.

8. The photoelectric conversion element according to claim 1 , further comprising a sealing member that shields the photoelectric conversion layer from an external environment of the photoelectric conversion element.

9. 9. A photoelectric conversion module comprising the photoelectric conversion elements according to claim 1 electrically connected in series or in parallel.

10. The photoelectric conversion module described in claim 9, wherein in a photoelectric conversion module having at least two adjacent photoelectric conversion elements, 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 the photoelectric conversion layer.

11. The photoelectric conversion module according to claim 9 , further comprising a sealing member that shields photoelectric conversion layers of the plurality of photoelectric conversion elements that constitute the photoelectric conversion module from an external environment of the photoelectric conversion module.

12. 12. An electronic device comprising at least one of a photoelectric conversion element and a photoelectric conversion module according to claim 1 and a device that operates using power generated by photoelectric conversion performed by at least one of the photoelectric conversion element and the photoelectric conversion module.

13. 12. An electronic device comprising: at least one of a photoelectric conversion element and a photoelectric conversion module according to claim 1; a storage battery capable of storing electric power generated by photoelectric conversion by at least one of the photoelectric conversion element and the photoelectric conversion module; and a device operated by the electric power stored in the storage battery.

14. A photoelectric conversion module according to any one of claims 9 to 11, A power supply IC; A power supply module comprising:

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