Photoelectric conversion element, photoelectric conversion module, and electronic device

Abstract

To provide a photoelectric conversion element that can obtain high output even with low illumination and stable output with little variation in output over time.SOLUTION: A photoelectric conversion element has a first electrode, a photoelectric conversion layer, and a second electrode, and the photoelectric conversion layer has a hole transport layer and the hole transport layer contains a tertiary amine pyridine compound and a secondary amine pyridine compound.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In recent years, the driving power of electronic circuits has become extremely low, and it has become possible to drive various electronic components such as sensors with very weak power (in the order of μW). In addition, when using sensors, it is expected that they will be applied to energy harvesting elements as independent power sources that can generate and consume electricity on the spot. Among these, solar cells, a type of photoelectric conversion element, are attracting attention as an element that can generate electricity anywhere there is light, even if the light is very weak.

[0003] In particular, photoelectric conversion elements such as solar cells are required to have output power and durability at low illuminance depending on the application.

[0004] In order to obtain good photoelectric conversion characteristics even when exposed to extremely weak light (10 Lux to 50 Lux) such as indoor light, a photoelectric conversion element has been proposed which has an electrode, a hole blocking layer, an electron transport layer, a hole transport layer, and an electrode in this order, and in which the hole transport layer contains a basic compound represented by a specific structural formula (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a photoelectric conversion element which can obtain a high output even with light of low illuminance, and which has little fluctuation in output over time and can obtain a stable output. [Means for solving the problem]

[0006] The photoelectric conversion element of the present invention as a means for solving the above problems comprises: A first electrode, a photoelectric conversion layer, and a second electrode, the photoelectric conversion layer has a hole transport layer, The hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine . and the content of the pyridine compound of the secondary amine is 20% by mass or less based on the total amount of the pyridine compound [Effect of the Invention]

[0007] According to the present invention, it is possible to provide a photoelectric conversion element that can obtain a high output even with low-intensity light, has little temporal variation in the output, and can obtain a stable output. [Brief Description of the Drawings]

[0008]

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Figure 18

MODE FOR CARRYING OUT THE INVENTION

[0009] (Photoelectric conversion element) The photoelectric conversion element of the present invention has a first electrode, a photoelectric conversion layer, and a second electrode. The photoelectric conversion layer has a hole transport layer and, if necessary, other layers. The hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine.

[0010] The inventors of the present invention have found that in the photoelectric conversion element of the present invention, since the hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine, a high output can be obtained even with low-intensity light, and the output variation over time is small, and a photoelectric conversion element capable of obtaining a stable output can be obtained.

[0011] In the present specification, the "photoelectric conversion element" means an element that converts light energy into electrical energy or an element that converts electrical energy into light energy. Specifically, examples include a solar cell or a photodiode. In the present invention, the layer includes not only a structure in which a plurality of films are stacked but also a case where it is a single film (single layer). The stacking direction means a direction perpendicular to the plane direction of each layer in the photoelectric conversion element. Also, connection means not only physical contact but also an electrical connection to such an extent that the effects of the present invention can be achieved. The photoelectric conversion element of the present invention has a first electrode, a photoelectric conversion layer, and a second electrode. The photoelectric conversion layer has at least an electron transport layer and a hole transport layer, and further, if necessary, has other members such as a first substrate, a second substrate, a hole blocking layer, and a sealing member.

[0012] <First substrate> There are no particular restrictions on the shape, structure, and size of the first substrate, and it can be appropriately selected according to the purpose. There are no particular restrictions on the material of the first substrate as long as it has translucency and insulation, and it can be appropriately selected according to the purpose. Examples include substrates such as glass, plastic film, and ceramic. Among these, when including a firing step for forming an electron transport layer as described later, a substrate having heat resistance with respect to the firing temperature is preferable. Further, as the first substrate, a flexible one is more preferable.

[0013] The substrate may be provided on either one or both of the outermost part on the first electrode side and the outermost part on the second electrode side of the photoelectric conversion element. Hereinafter, the substrate provided on the outermost part on the first electrode side is referred to as the first substrate, and the substrate provided on the outermost part on the second electrode side is referred to as the second substrate. There are no particular restrictions on the average thickness of the substrate, and it can be appropriately selected according to the purpose. Examples include 50 μm or more and 5 mm or less.

[0014] <The first electrode> As for the shape and size of the first electrode, there are no particular limitations, and it can be appropriately selected according to the purpose. As for the structure of the first electrode, there are no particular limitations, and it can be appropriately selected according to the purpose. It may have a single-layer structure or a structure in which a plurality of materials are laminated. As for the material of the first electrode, there are no particular limitations as long as it has transparency and conductivity with respect to visible light, and it can be appropriately selected according to the purpose. Examples include transparent conductive metal oxides, carbon, metals, etc.

[0015] Examples of the transparent conductive metal oxide include indium tin oxide (hereinafter referred to as "ITO"), fluorine-doped tin oxide (hereinafter referred to as "FTO"), antimony-doped tin oxide (hereinafter referred to as "ATO"), niobium-doped tin oxide (hereinafter referred to as "NTO"), aluminum-doped zinc oxide, indium zinc oxide, niobium titanium oxide, etc. Examples of the carbon include carbon black, carbon nanotubes, graphene, fullerenes, etc. Examples of the metal include gold, silver, aluminum, nickel, indium, tantalum, titanium, etc. These may be used alone or in combination of two or more. Among these, transparent conductive metal oxides with high transparency are preferred, and ITO, FTO, ATO, NTO, and AZO are more preferred.

[0016] There are no particular limitations on the average thickness of the first electrode, and it can be appropriately selected according to the purpose. However, it is preferably 5 nm or more and 100 μm or less, and more preferably 50 nm or more and 10 μm or less. 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 light transmittance.

[0017] The first electrode can be formed by known methods such as sputtering, evaporation, spraying, etc.

[0018] Further, the first electrode is preferably formed on the first substrate, and a commercially available integrated product in which the first electrode is previously formed on the first substrate can be used. Examples of the 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 examples of the integrated commercially available products include a transparent electrode doped with cations or anions having different valences in tin oxide or indium oxide, or a glass substrate provided with a metal electrode having a structure such as a mesh shape or a stripe shape through which light can pass. These may be used alone or in combination of two or more and mixed or laminated. Further, for the purpose of reducing the electrical resistance value, metal lead wires or the like may be used in combination.

[0019] Also, the electrodes in the integrated commercially available product may be appropriately processed to produce a substrate on which a plurality of first electrodes are formed in order to produce a photoelectric conversion module described later. Examples of the material of the metal lead wire include aluminum, copper, silver, gold, platinum, nickel, etc. The metal lead wire can be formed on the substrate by, for example, vapor deposition, sputtering, crimping, etc., and an ITO or FTO layer can be provided thereon or provided on ITO or FTO to be used in combination.

[0020] <Hole blocking layer> It is preferable to further form the hole blocking layer, which is very effective for improving the output and its sustainability. The hole blocking layer is formed between the first electrode and the electron transport layer. In other words, in the present invention, it is preferable to further have the hole blocking layer between the first electrode and the photoelectric conversion layer. The hole-blocking layer can transport the electrons generated by the photosensitizing compound and transported to the electron transport layer to the first electrode, and can prevent contact with the hole transport layer. That is, it is possible to suppress a decrease in power caused by recombination (so-called reverse electron transfer) of holes in the hole transport layer and electrons on the electrode surface when the hole transport layer is in contact with the electrode. Thereby, the hole-blocking layer can make it difficult for holes to flow into the first electrode and suppress a decrease in output due to recombination of electrons and holes. The effect of the hole-blocking layer is particularly remarkable in a solid-state dye-sensitized solar cell. This is because, compared with a wet dye-sensitized solar cell using an electrolytic solution, in a solid-state dye-sensitized solar cell using an organic hole transport material or the like, the recombination (reverse electron transfer) rate of holes in the hole transport material and electrons on the electrode surface is fast.

[0021] The material of 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 according to the purpose. For example, elemental semiconductors such as silicon and germanium, compound semiconductors typified by metal chalcogenides, and compounds having a perovskite structure can be mentioned.

[0022] Examples of the metal chalcogenide 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, lead; and tellurides of cadmium. Examples of other compound semiconductors include phosphides of zinc, gallium, indium, cadmium, etc.; gallium arsenide, copper-indium-selenide, copper-indium-sulfide, etc. Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate, etc. Among these, oxide semiconductors are preferred, and titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide, tin oxide, etc. are more preferred, and titanium oxide is even more preferred. These may be used alone or in combination of two or more. They may be in a single layer or laminated. Also, the crystal form of these semiconductors is not particularly limited and can be appropriately selected according to the purpose, and it may be a single crystal, a polycrystal, or an amorphous.

[0023] The method for forming the hole blocking layer is not particularly limited and can be appropriately selected according to the purpose. However, in order to suppress the loss current in indoor light, a high internal resistance is required, and the film formation method is also important. The method for producing the hole blocking layer is not particularly limited and can be appropriately selected according to the purpose. For example, methods for forming a thin film in a vacuum (vacuum film formation method), wet film formation methods, etc. can be mentioned. Generally, the sol-gel method which is a wet film formation method can be mentioned, but the film density is low and the loss current cannot be sufficiently suppressed. Therefore, more preferably, it is a dry film formation such as a sputtering method, and the film density is sufficiently high to suppress the loss current. Examples of the vacuum film formation method include sputtering method, pulsed laser deposition method (PLD method), ion beam sputtering method, ion assist method, ion plating method, vacuum evaporation method, atomic layer deposition method (ALD method), chemical vapor deposition method (CVD method), etc. Examples of the wet film formation method include, for example, the sol-gel method. The sol-gel method is a method in which a gel is produced from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then densification is promoted by heat treatment. When the sol-gel method is used, the coating method of the sol solution is not particularly limited and can be appropriately selected according to the purpose. For example, dip coating, spray coating, wire bar coating, spin coating, roller coating, blade coating, gravure coating, and, as wet printing methods, relief printing, offset printing, gravure printing, intaglio printing, rubber plate printing, screen printing, etc. can be mentioned. Also, the temperature during the heat treatment after applying the sol solution is preferably 80°C or higher, more preferably 100°C or higher.

[0024] The average thickness of the hole blocking layer is not particularly limited and can be appropriately selected according to the purpose, but is preferably 5 nm or more and 1 μm or less, more preferably 500 nm or more and 700 nm or less in wet film formation, and more preferably 10 nm or more and 30 nm or less in dry film formation.

[0025] <Photoelectric conversion layer> The photoelectric conversion layer has an electron transport layer, a photosensitizing compound, and a hole transport layer, and further has other members as required. The photoelectric conversion layer may be a single layer or a multilayer in which a plurality of layers are laminated.

[0026] <<Electron transport layer>> The photoelectric conversion element has the electron transport layer having a photosensitizing compound. The electron transport layer is preferably disposed between the first electrode and the photosensitizing compound. The electron transport layer is formed for the purpose of transporting electrons generated by the photosensitizing compound to the first electrode or the hole blocking layer. For this reason, the electron transport layer is preferably disposed adjacent to the first electrode or the hole blocking layer.

[0027] The structure of the electron transport layer is not particularly limited and can be appropriately selected according to the purpose. However, in at least two adjacent photoelectric conversion elements, the electron transport layers may extend to each other, but it is preferably not extended. Further, the structure of the electron transport layer may be a single layer or a multilayer in which a plurality of layers are stacked.

[0028] The electron transport layer contains an electron transporting material and may contain other materials as necessary.

[0029] The electron transporting material is not particularly limited and can be appropriately selected according to the purpose, but a semiconductor material is preferred. The semiconductor material has a particulate shape, and it is preferably formed into a porous film by joining these. A photosensitizing compound is chemically or physically adsorbed on the surface of the semiconductor fine particles constituting the porous electron transport layer.

[0030] The semiconductor material is not particularly limited, and known ones can be used. For example, elemental semiconductors, compound semiconductors, compounds having a perovskite structure, etc. can be mentioned. Examples of the elemental semiconductor include silicon, germanium, etc. Examples of the compound semiconductor include metal chalcogenides, specifically, oxide semiconductors such as titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum, etc.; sulfide semiconductors such as cadmium, zinc, lead, silver, antimony, bismuth, etc.; selenide semiconductors such as cadmium, lead, etc.; telluride semiconductors such as cadmium, etc. Other compound semiconductors include phosphide semiconductors such as zinc, gallium, indium, cadmium, etc., gallium arsenide, copper-indium-selenide semiconductors, copper-indium-sulfide semiconductors, etc. Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate, etc. Among these, oxide semiconductors are preferred, and titanium oxide, zinc oxide, tin oxide, and niobium oxide are more preferred. When the electron transport material of the electron transport layer is titanium oxide, since the conduction band level is high, it is advantageous in that a high open-circuit voltage can be obtained and high photoelectric conversion characteristics can be obtained. These may be used alone or in combination of two or more. Also, the crystal form of the semiconductor material is not particularly limited and can be appropriately selected according to the purpose, and it may be a single crystal, a polycrystal, or an amorphous. Note that the semiconductor material is preferably in the form of fine particles.

[0031] The average particle diameter 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. Also, a larger semiconductor material may be mixed or laminated, and the conversion efficiency may be improved by the effect of scattering incident light. In this case, the average particle diameter is preferably 50 nm or more and 500 nm or less.

[0032] The average thickness of the electron transport layer is not particularly limited and can be appropriately selected according to the purpose, but is preferably 50 nm or more and 100 μm or less, more preferably 100 nm or more and 50 μm or less, and still more preferably 120 nm or more and 10 μm or less. 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 ensured, the light capture rate can be maintained high, the diffusion distance of the injected electrons is also less likely to increase, and it is advantageous in that the loss due to charge recombination can be reduced.

[0033] The method for fabricating the electron transport layer is not particularly limited and can be appropriately selected according to the purpose. For example, methods for forming a thin film in a vacuum such as sputtering, wet film formation methods, wet printing methods, etc. can be mentioned. Among these, from the perspective of manufacturing cost, the wet film formation method is preferred. A method of preparing a paste (dispersion of semiconductor material) in which the powder or sol of the semiconductor material is dispersed and applying it on the first electrode as the electron collecting electrode substrate or on the hole blocking layer is more preferred. The wet film formation method is not particularly limited and can be appropriately selected according to the purpose. For example, dipping method, spraying method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, die coating method, etc. can be mentioned. As the wet printing method, for example, various methods such as letterpress, offset, gravure, intaglio, rubber plate, screen printing, etc. can be used.

[0034] As a method for preparing the dispersion of the semiconductor material, for example, a method of mechanically pulverizing using a known milling device, etc. can be mentioned. By this method, a dispersion of the semiconductor material can be prepared by dispersing particulate semiconductor material alone or a mixture of semiconductor material and resin in water or a solvent. Examples of the resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic ester, methacrylic ester, etc., silicone resin, phenoxy resin, polysulfone resin, polyvinyl butyral resin, polyvinyl formal resin, polyester resin, cellulose ester resin, cellulose ether resin, urethane resin, phenol resin, epoxy resin, polycarbonate resin, polyarylate resin, polyamide resin, polyimide resin, etc. These may be used alone or in combination of two or more.

[0035] Examples of the solvent include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, hydrocarbon solvents, etc. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, α-terpineol, and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like. Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate, and the like. Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane, and the like. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like. Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene, and the like. 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, cumene, and the like. These may be used alone or in combination of two or more.

[0036] In the dispersion containing the semiconductor material or the paste containing the semiconductor material obtained by the sol-gel method or the like, an acid, a surfactant, a chelating agent, etc. may be added to prevent re-aggregation of the particles. Examples of the acid include hydrochloric acid, nitric acid, acetic acid, and the like. Examples of the surfactant include polyoxyethylene octyl phenyl ether, and the like. Examples of the chelating agent include acetylacetone, 2-aminoethanol, ethylenediamine, and the like. In addition, for the purpose of improving the film-forming property, adding a thickening agent is also an effective means. Examples of the thickening agent include polyethylene glycol, polyvinyl alcohol, ethyl cellulose, and the like.

[0037] After applying the dispersion or paste containing the semiconductor material, the semiconductor material particles can be electronically contacted, and then fired to improve the film strength and adhesion to the substrate, irradiated with microwaves or electron beams, or irradiated with laser light. These treatments may be performed alone or in combination of two or more.

[0038] When firing the electron transport layer formed from the semiconductor material, the firing temperature is not particularly limited and can be appropriately selected according to the purpose. However, if the temperature is too high, the resistance of the substrate may increase or it may melt. Therefore, a temperature of 30°C or higher and 700°C or lower is preferable, and a temperature of 100°C or higher and 600°C or lower is more preferable. Also, the firing time is not particularly limited and can be appropriately selected according to the purpose, but a time of 10 minutes or more and 10 hours or less is preferable. When irradiating the electron transport layer formed from the semiconductor material with microwaves, the irradiation time is not particularly limited and can be appropriately selected according to the purpose, but a time of 1 hour or less is preferable. In this case, irradiation may be performed from the side where the electron transport layer is formed or from the side where the electron transport layer is not formed.

[0039] After firing the electron transport layer made of the semiconductor material, for the purpose of increasing the surface area of the electron transport layer and enhancing the electron injection efficiency from the photosensitizing compound described later to the semiconductor material, for example, chemical plating using an aqueous solution of titanium tetrachloride or a mixed solution with an organic solvent, or electrochemical plating treatment 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 nm can form a porous structure. Such a nanoporous structure has a very high surface area, and the surface area can be represented using a roughness factor. The roughness factor is a numerical value representing the actual surface area inside the pores with respect to the area of the semiconductor particles applied to the first substrate. Therefore, as the roughness factor, the larger the better, but from the relationship with the average thickness of the electron transport layer, 20 or more is preferable.

[0040] Further, a photosensitizing compound may be provided between the electron transport layer and the hole transport layer.

[0041] <<Photosensitizing Compound>> In the present invention, for further improvement of the conversion efficiency, it is preferable to adsorb the photosensitizing compound on the surface of the electron-transporting semiconductor of the electron transport layer. The photosensitizing compound is not particularly limited as long as it is a compound that is photoexcited by the excitation light used, and can be appropriately selected according to the purpose. For example, metal complex compounds described in JP-T-7-500630, JP-A-10-233238, JP-A-2000-26487, JP-A-2000-323191, JP-A-2001-59062, etc.; coumarin compounds described in JP-A-10-93118, JP-A-2002-164089, JP-A-2004-95450, J. Phys. Chem. C, 7224, Vol. 111 (2007), etc.; polyene compounds described in JP-A-2004-95450, Chem. Commun., 4887 (2007), etc.; indoline compounds described in JP-A-2003-264010, JP-A-2004-63274, JP-A-2004-115636, JP-A-2004-200068, JP-A-2004-235052, J. Am. Chem. Soc., 12218, Vol. 126 (2004), Chem. Commun., 3036 (2003), Angew. Chem. Int. Ed., 1923, Vol. 47 (2008), etc.; thiophene compounds described in J. Am. Chem. Soc., 16701, Vol. 128 (2006), J. Am. Chem. Soc., 14256, Vol. 128 (2006), etc.; cyanine dyes described in JP-A-11-86916, JP-A-11-214730, JP-A-2000-106224, JP-A-2001-76773, JP-A-2003-7359, etc.; merocyanine dyes described in JP-A-11-214731, JP-A-11-238905, JP-A-2001-52766, JP-A-2001-76775, JP-A-2003-7360, etc.; 9-aryl xanthene compounds described in JP-A-10-92477, JP-A-11-273754, JP-A-11-273755, JP-A-2003-31273, etc.; triarylmethane compounds described in JP-A-10-93118, JP-A-2003-31273, etc.; JP-A-9-199744, JP-A-10-233238, JP-A-11-204821, JP-A-11-265738, J. Phys. Chem., 2342, Vol. 91 (1987), J. Phys. Chem. B, 6272, Vol.Examples include phthalocyanine compounds and porphyrin compounds described in 97(1993), Electroanal.Chem., 31, Vol.537(2002), JP-A-2006-032260, J.Porphyrins Phthalocyanines, 230, Vol.3(1999), Angew.Chem.Int.Ed., 373, Vol.46(2007), Langmuir, 5436, Vol.24(2008), etc. Among these, metal complex compounds, coumarin compounds, polyene compounds, indoline compounds, and thiophene compounds are preferred. For example, compounds of the following structural formulas (1), (2), and (3) manufactured by Mitsubishi Paper Mills Limited are preferably used.

[0042]

Chemical formula

[0043]

Chemical formula

[0044]

Chemical formula

[0045] More preferably used photosensitizing compounds include compounds containing the following general formula (5).

[0046]

Chemical formula

[0047] Z1 and Z2 each independently represent a substituent forming a cyclic structure. Z1 includes condensed hydrocarbon compounds such as a benzene ring and a naphthalene ring, and heterocycles such as a thiophene ring and a furan ring, and each may have a substituent. Specific examples of the substituent include the above-mentioned alkyl group, alkoxy groups such as a methoxy group, an ethoxy group, and a 2-isopropoxy group. Z2 includes (A-1) to (A-22) shown below. Note that m represents an integer from 0 to 2.

[0048]

Chemical formula

[0049] Among the above compounds, the compound represented by the following general formula (6) is more preferably used.

Chemical formula

[0050]

Chemical formula

[0051] [Chemistry]

[0052] [Chemistry]

[0053] [Chemistry]

[0054] [Chemistry]

[0055] Furthermore, as the photosensitizing compound preferably used, compounds containing the following general formula (7) may also be mentioned.

[0056] [Chemistry] However, in the general formula (7), Ar1 and Ar2 represent aryl groups which may have substituents. R1 and R2 represent linear or branched alkyl groups having 4 to 10 carbon atoms. X represents any substituent represented by the following structural formula.

[0057] [Chemistry]

[0058] Among the photosensitizing compounds represented by the above general formula (7), the compounds represented by the following general formula (7’) are more preferably used.

[0059] [Chemistry] However, in the general formula (7), Ar4 and Ar5 represent phenyl groups which may have substituents, or naphthyl groups which may have substituents. Ar6 represents a phenyl group which may have substituents, or a thiophene group which may have substituents. Specific exemplary compounds of the photosensitizing compounds represented by the general formula (7) and the general formula (7') are shown below, but the photosensitizing compounds in the present invention are not limited thereto.

[0060]

Chemical formula

[0061]

Chemical formula

[0062]

Chemical formula

[0063]

Chemical formula

[0064]

Chemical formula

[0065] These photosensitizing compounds may contain one kind or two or more kinds. LED light sources with different colors such as warm color, cold color, and white are used, and the spectra are different depending on the color. For example, when the color temperature is 3,000K, the region around 600nm becomes relatively strong, showing a reddish incandescent color; when the color temperature is 5,000K, it is a balanced daylight white color; when the color temperature exceeds 6,500K, the region around 450nm becomes relatively strong, showing a bluish daylight color. Therefore, it is preferable that a high output can be maintained even when the color temperature of the used LED is different. In this case, mixing different photosensitizing compounds may be effective in reducing the output difference due to the color temperature.

[0066] As a method for adsorbing a photosensitizing compound on the surface of the semiconductor material of the electron transport layer, for example, a method of immersing the electron transport layer containing the semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, a method of applying and adsorbing a solution of the photosensitizing compound or a dispersion of the photosensitizing compound to the electron transport layer can be used. In the case of the method of immersing the electron transport layer formed of the semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, an immersion method, a dip method, a roller method, an air knife method, etc. can be used.

[0067] In the case of the method of applying and adsorbing the solution of the photosensitizing compound or the dispersion of the photosensitizing compound to the electron transport layer, a wire bar method, a slide hopper method, an extrusion method, a curtain method, a spin method, a spray method, etc. can be used. Also, it is possible to adsorb in a supercritical fluid using carbon dioxide or the like.

[0068] When adsorbing the photosensitizing compound to the semiconductor material, a condensing agent may be used in combination. As the condensing agent, any one that has a catalytic action to physically or chemically bond the photosensitizing compound to the surface of the semiconductor material, or that acts stoichiometrically and favorably shifts the chemical equilibrium may be used. Furthermore, as a condensation aid, a thiol, a hydroxy compound, or the like may be added.

[0069] Examples of the solvent for dissolving or dispersing the photosensitizing compound include water, an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, an amide solvent, a halogenated hydrocarbon solvent, a hydrocarbon solvent, and the like. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like. Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate, and the like. Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane and the like. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone and the like. Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene and the like. 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, cumene and the like. These may be used alone or in combination of two or more.

[0070] Depending on the type of the photosensitizing compound, there are those that work more effectively when aggregation between compounds is suppressed, so an aggregation-dissociating agent may be used in combination. Examples of the aggregation-dissociating agent include steroid compounds such as cholic acid and chenodeoxycholic acid, long-chain alkyl carboxylic acids or long-chain alkyl phosphonic acids.

[0071] The content of the aggregation-dissociating 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.

[0072] When adsorbing the photosensitizing compound, or the photosensitizing compound and the aggregation-dissociating agent, onto the surface of the semiconductor material constituting the electron transport layer, the temperature is preferably -50°C or higher and 200°C or lower. The adsorption time is preferably 5 seconds or longer and 1,000 hours or shorter, more preferably 10 seconds or longer and 500 hours or shorter, still more preferably 1 minute or longer and 150 hours or shorter. The adsorption step is preferably carried out in the dark. Also, the adsorption step may be carried out statically or with stirring. There is no particular limitation on the stirring method, and it can be appropriately selected according to the purpose. For example, methods using a stirrer, ball mill, paint conditioner, sand mill, attritor, disperser, ultrasonic dispersion, etc. can be mentioned.

[0073] In the present invention, it is also possible and effective to provide a perovskite layer. The perovskite layer means a layer containing a perovskite compound and absorbing light to sensitize the electron transport layer. Therefore, the perovskite layer is preferably disposed adjacent to the electron transport layer. The perovskite compound is a composite material of an organic compound and an inorganic compound and is represented by the following general formula (X). XαYβMγ ··· General formula (X)

[0074] In the above general formula (X), the ratio of α:β:γ is 3:1:1, and β and γ represent integers greater than 1. Further, for example, X can be a halogen ion, Y can be an alkylamine compound ion, and M can be a metal ion, etc.

[0075] There is no particular limitation on X in the above general formula (X), and it can be appropriately selected according to the purpose. For example, halogen ions such as chlorine, bromine, and iodine can be mentioned. These may be used alone or in combination of two or more. Examples of Y in the above general formula (X) include alkylamine compound ions such as methylamine, ethylamine, n-butylamine, and formamidine, and cesium, potassium, rubidium, etc. Also, in the case of a perovskite compound of lead halide-methylammonium, when the halogen ion is Cl, the peak λmax of the light absorption spectrum is about 350 nm, when it is Br, it is about 410 nm, and when it is I, it is about 540 nm, and the available spectral width (band region) is different as it shifts to the longer wavelength side in order. M in the general formula (X) above is not particularly limited and can be appropriately selected according to the purpose. For example, metals such as lead, indium, antimony, tin, copper, and bismuth can be mentioned.

[0076] In addition, the perovskite layer preferably exhibits a layered perovskite structure in which a layer composed of a metal halide and a layer in which organic cation molecules are arranged are alternately laminated.

[0077] The method for forming the perovskite layer is not particularly limited and can be appropriately selected according to the purpose. For example, a method of applying a solution in which a metal halide and an alkylamine halide are dissolved or dispersed and then drying it can be mentioned. In addition, as a method for forming the perovskite layer, for example, a two-step precipitation method in which a solution in which a metal halide is dissolved or dispersed is applied and dried, and then immersed in a solution in which an alkylamine halide is dissolved to form a perovskite compound can be mentioned.

[0078] Furthermore, as a method for forming the perovskite layer, for example, a method of adding a poor solvent (a solvent with low solubility) for the perovskite compound while applying a solution in which a metal halide and an alkylamine halide are dissolved or dispersed to precipitate crystals can be mentioned. In addition, as a method for forming the perovskite layer, for example, a method of vapor-depositing a metal halide in a gas filled with methylamine or the like can be mentioned. Among these, a method of adding a poor solvent for the perovskite compound while applying a solution in which a metal halide and an alkylamine halide are dissolved or dispersed to precipitate crystals is preferable.

[0079] The method for applying the solution is not particularly limited and can be appropriately selected according to the purpose. For example, dipping method, spin coating method, spraying method, dipping method, roller method, air knife method, etc. can be mentioned. In addition, as a method for applying the solution, for example, a method of precipitating in a supercritical fluid using carbon dioxide or the like may also be used. In addition, the perovskite layer may contain a photosensitizing compound. The sensitizing dye is not particularly limited as long as it is a compound that is photoexcited by the excitation light used, and can be appropriately selected according to the purpose. For example, the aforementioned photosensitizing compounds can be mentioned. There is no particular limitation on the method for forming the perovskite layer containing the sensitizing dye, and it can be appropriately selected according to the purpose. For example, a method of mixing a perovskite compound and a photosensitizing compound, a method of adsorbing a photosensitizing compound after forming the perovskite layer, etc. can be mentioned.

[0080] <<Hole transport layer>> The hole transport layer is a layer that functions to transport holes (positive holes).

[0081] The form of the hole transport layer is not particularly limited as long as it has the function of transporting holes, and can be appropriately selected according to the purpose. For example, an electrolytic solution in which a redox couple is dissolved in an organic solvent, a gel electrolyte in which a liquid in which a redox couple is dissolved in an organic solvent is impregnated in a polymer matrix, a molten salt containing a redox couple, a solid electrolyte, an inorganic hole transport material, an organic hole transport material, etc. can be mentioned. Among these, a solid electrolyte is preferable, and an organic hole transport material is more preferable. These may be used alone or in combination of two or more.

[0082] The hole transport layer preferably contains a pyridine compound, a p-type semiconductor material, and an alkali metal salt.

[0083] - Pyridine compound - The pyridine compound is a compound having a pyridine ring structure. The pyridine ring is a structure represented by the following structural formula (4), and the compound having a pyridine ring structure is a compound containing at least one pyridine ring. The basic compound such as the pyridine compound is considered to be present at the interface near the electron transport layer, and is considered to suppress the reverse electron transfer from the electron transport layer (that is, the electron transfer from the electron transport layer to the hole transport layer).

[0084]

Chem.

[0085] By containing a pyridine compound in the hole transport layer, the open voltage can be increased, and as a result, the effect of increasing the output can be obtained. Among these pyridine compounds, the compound represented by the following general formula (1) is more preferable.

Chem.

[0086] Here, the pyridine compound of a tertiary amine is a pyridine compound in which the R1 and the R2 are substituted with at least one of an alkyl group, a benzyl group, and an aryl group, and the pyridine compound of a secondary amine is a pyridine compound in which one of the R1 and the R2 is hydrogen and the other is substituted with at least one of an alkyl group, a benzyl group, and an aryl group. Among the pyridine compounds, a pyridine compound in which one or both of the R1 and the R2 are benzyl groups is more preferable.

[0087] Examples of the pyridine compound of a tertiary amine include, but are not limited to, the exemplary compounds (C-1) to (C-20) shown below. These may be used alone or in combination of two or more.

[0088] [Chem.]

[0089] [Chem.]

[0090] Examples of the pyridine compound of the secondary amine include, but are not limited to, the exemplary compounds (C-21) to (C-27) shown below. These may be used alone or in combination of two or more. [Chem.]

[0091] By containing the pyridine compound of the tertiary amine in the hole transport layer, not only can the output of the photoelectric conversion element be increased, but also the durability and stability can be enhanced, and it is particularly effective in improving the durability and stability against low-intensity light. Furthermore, by containing the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine in the hole transport layer, the change in output over time of the photoelectric conversion element can be reduced, and in particular, it becomes possible to suppress the temporary decrease in output after the start of power generation, thereby improving the output stability.

[0092] The content (total amount) of the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine is preferably 20 mol% or more and 65 mol% or less, and more preferably 35 mol% or more and 50 mol% or less, based on the content of the hole transport material described later. By the content (total amount) of the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine being 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 time in various environments. Further, the content of the pyridine compound of the secondary amine is preferably 20% by mass or less, more preferably 15% by mass or less, based on the total amount of the pyridine compounds. On the other hand, regarding the lower limit, 1% by mass or more is preferable, and 5% by mass or more is more preferable. When the content of the pyridine compound of the secondary amine is within the preferable range, it is possible to suppress the output decrease that was temporarily observed after the start of power generation without adversely affecting the durability, and improve the output stability.

[0093] In addition, the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine can be specified from the photoelectric conversion element or the photoelectric conversion module using a conventional analysis method. For example, nuclear magnetic resonance method (NMR), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), liquid chromatography (HPLC), gas chromatography (GC), mass spectrometry (MS), etc. can be mentioned, and further, it is possible to specify the pyridine compound by a method combining these.

[0094] -p-type semiconductor material- The hole transport layer contains a p-type semiconductor material in order to obtain the function of transporting holes. The ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material. When the ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material, it is possible to achieve both high photoelectric conversion properties and stability over time even under low-intensity light. The p-type semiconductor material is not particularly limited and can be appropriately selected according to the purpose. For example, inorganic p-type semiconductor materials, organic p-type semiconductor materials, etc. can be mentioned. The inorganic p-type semiconductor material is not particularly limited and can be appropriately selected according to the purpose. For example, CuSCN, CuI, CuBr, NiO, V2O5, graphene oxide, etc. can be mentioned. Among these, organic p-type semiconductor materials are preferable.

[0095] There are no particular restrictions on the organic p-type semiconductor material or the like, and it can be appropriately selected according to the purpose. For example, a known organic p-type semiconductor material can be used. Examples of the known organic p-type semiconductor material include oxadiazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, oxadiazole compounds, tetraarylbenzidine compounds, stilbene compounds, spiro-type compounds, and the like. These may be used alone or in combination of two or more. Among these, spiro-type compounds are preferred.

[0096] As the spiro-type compound, a compound containing the following general formula (20) is preferred.

[0097]

Chemical formula

[0098]

Chemical formula

[0099]

Chemical formula

[0100]

Chemical formula

[0101]

Chemical formula

[0102] [Chemistry]

[0103] [Chemistry]

[0104] [Chemistry]

[0105] Further, as the spiro-type compound as the hole transport material, the compound represented by the following general formula (4) can be particularly preferably used. [Chemistry] However, in the general formula (4), R3 represents a hydrogen atom or an alkyl group.

[0106] For example, among the above (D-1) to (D-20), those represented by the general formula (4) are (D-7) and (D-10).

[0107] In addition to having high hole mobility, these spiro-type compounds have two twisted and bonded benzidine backbone molecules, thus forming an electron cloud close to a spherical shape. Due to the good hopping conductivity between molecules, they exhibit excellent photoelectric conversion characteristics. Also, due to their high solubility, they can dissolve in various organic solvents, and since they are amorphous (amorphous substances without a crystal structure), they are easily filled densely in the porous electron transport layer. Furthermore, since they do not have a light absorption characteristic of 450 nm or more, they can efficiently absorb light by the photosensitizing compound, which is particularly preferable for solid-state dye-sensitized solar cells.

[0108] - Alkali metal salt - When the hole transport layer contains an alkali metal salt, the output can be improved, and furthermore, the light irradiation resistance and the high-temperature storage resistance can be improved. Specific examples of the alkali metal salts include those shown in the following (C-1) to (C-86), those represented by the following general formula (2), etc., but are not limited thereto.

[0109]

Chemical formula

[0110]

Chemical formula

[0111]

Chemical formula

[0112]

Chemical formula

[0113]

Chemical formula

[0114] Examples of the lithium salt represented by the general formula (2) include lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), 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 bis(trifluoromethanesulfonyl)imide (Li-TFSI) and lithium (fluorosulfonyl)(trifluoromethylsulfonyl)imide (Li-FTFSI) are particularly preferred.

[0115] Structural formulas of specific examples of the lithium salt represented by the general formula (2) are as follows.

[0116]

Chemical formula

[0117] The lithium salt represented by the general formula (2) is involved in the movement of charges, and good photoelectric conversion characteristics can be obtained by containing this lithium salt.

[0118] Here, for example, when coating is performed using a coating solution for forming a hole transport layer containing the lithium salt represented by the general formula (2), in the formed film, the above lithium salt does not necessarily need to be contained in the state of a salt in which an anion and a cation are bonded, and may be in a state in which lithium cations and anions are separated. Specifically, when the lithium salt represented by the general formula (2) forms a hole transport layer in a state of being contained in a coating solution for forming a hole transport layer, for example, lithium cations migrate to the electron transport layer, and the inventors have found that the electron transport layer contains more lithium cations than the hole transport layer. On the other hand, regarding anions, for example, although they partially migrate to the electron transport layer, the inventors have found that the hole transport layer contains more anions than the electron transport layer. In the present invention, it is preferable that the cation and anion of the lithium salt represented by the general formula (2) are separated and each forms a different distribution state. By being contained in the photoelectric conversion layer, even in a low-temperature environment, a high output can be obtained for low-intensity light, and the effect of excellent output sustainability can be further improved.

[0119] The form of the hole transport layer is not particularly limited as long as it has a function of transporting holes, and can be appropriately selected according to the purpose. For example, an electrolyte solution in which a redox couple is dissolved in an organic solvent, a gel electrolyte in which a liquid in which a redox couple is dissolved in an organic solvent is impregnated in a polymer matrix, a molten salt containing a redox couple, a solid electrolyte, an inorganic hole transport material, an organic hole transport material, etc. can be mentioned. Among these, a solid electrolyte is preferable, and an organic hole transport material is more preferable. These may be used alone or in combination of two or more.

[0120] In addition to the above-mentioned lithium salt, other lithium salts can also be contained in the hole transport layer in the photoelectric conversion layer. These lithium salts may have, for example, symmetric anion species. For example, lithium bis(fluorosulfonyl)imide (Li-FSI), lithium bis(pentafluoroethanesulfonyl)imide (Li-BETI), lithium bis(nonafluorobutanesulfonyl)imide, etc. can be mentioned. Also, cyclic imides such as lithium(cyclohexafluoropropane)(disulfone)imide can be mentioned. However, since these lithium salts have low compatibility due to the symmetric anions and it is difficult to increase the addition amount, even if added, a small amount is preferable.

[0121] The content of the lithium salt represented by the general formula (2) is preferably 5 mol% or more and 50 mol% or less, more preferably 20 mol% or more and 35 mol% or less, based on the hole transport material. When the content is within the above range, the output for low-intensity light is high, the maintenance rate of the output is improved, and both high durability and high output can be achieved.

[0122] The cation of the lithium salt represented by the general formula (2) is considered to be present at the interface near the electron transport layer, and the anion of the lithium salt represented by the general formula (2) is considered to be doped into the hole transport layer.

[0123] The content of the alkali metal salt is preferably 30 mol% or more and 80 mol% or less, more preferably 50 mol% or more and 70 mol% or less, based on the total amount of the hole transport material.

[0124] In addition, the lithium cation in the lithium salt represented by the general formula (2) may be in a state of migrating to the electron transport layer. For example, a state in which more than half of the lithium cations are contained in the electron transport layer described later may be acceptable. Note that the hole transport layer in the present invention is more preferably filled inside the electron transport layer described later because the output can be further improved. In this case, the hole transport layer filled in the electron transport layer is also treated as the hole transport layer.

[0125] - Oxidizing agent - The hole transport layer preferably contains an oxidizing agent. When the hole transport layer contains the oxidizing agent, a part of the organic hole transport material becomes a radical cation, thereby improving the conductivity and enhancing the durability and stability of the output characteristics. When the organic hole transport material is oxidized by the oxidizing agent, it exhibits good hole conductivity and can suppress the release (reduction) of the oxidized state due to the influence of the surrounding environment of the photoelectric conversion layer, thereby showing good stability over time.

[0126] There are no particular restrictions on the oxidizing agent, and it can be appropriately selected according to the purpose. For example, tris(4-bromophenyl)ammonium hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluoroborate, silver nitrate, metal complexes, hypervalent iodine compounds, etc. can be mentioned. These may be used alone or in combination of two or more. Among these, metal complexes and hypervalent iodine compounds are preferred. When the oxidizing agent is a metal complex or a hypervalent iodine compound, it is advantageous in that it has a high solubility in an organic solvent and can be added in a large amount.

[0127] --Metal complex-- The metal complex is composed of, for example, a metal cation, a ligand, and an anion.

[0128] There are no particular restrictions on the metal cation, and it can be appropriately selected according to the purpose. For example, cations such as chromium, manganese, zinc, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, vanadium, gold, platinum, etc. can be mentioned. Among these, cations of manganese, zinc, iron, cobalt, nickel, copper, ruthenium, silver, and vanadium are preferred, and cobalt complexes are more preferred.

[0129] The ligand preferably contains at least one 5- or 6-membered heterocyclic ring containing at least one nitrogen, and may have a substituent. Specific examples include, but are not limited to, the following.

[0130]

Chemical formula

[0131]

Chemical formula

[0132] [Chemistry]

[0133] Examples of the anion include hydride ion (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 (CH3COO - ), 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 (CF3SO2-), 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 ion (O 2- ) Sulfide ion (S 2- ) 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- ) Hydrogen phosphate ion (HPO4 2- ) Tetrahydroxozincate(II) ion ([Z n (OH)4] 2- ) Tetracyanozincate(II) ion ([Zn(CN)4] 2- ) Tetrachlorocuprate(II) ion ([CuCl4] 2- ) Phosphate ion (PO4 3- ) Hexacyanoferrate(III) ion ([Fe(CN)6] 3- ) Bis(thiosulfato)argentate(I) ion ([Ag(S2O3)2] 3- ) Hexacyanoferrate(II) ion ([Fe(CN)6] 4- ) and the like. Among these, tetrafluoroborate ion, hexafluorophosphate ion, tetracyanoborate ion, bis(trifluoromethylsulfonyl)amine ion, and perchlorate ion are preferable.

[0134] As the metal complex, it is particularly preferable to add a trivalent cobalt complex. When a trivalent cobalt complex is added as an oxidizing agent, it becomes possible to oxidize and stabilize the hole transport material, and the hole transport property can be enhanced. In the present invention, for example, it is preferable to use trivalent cobalt complex as the cobalt complex added to the coating solution for forming the hole transport layer. However, it is preferable that the hole transport layer of the photoelectric conversion element obtained by using the coating solution for forming the hole transport layer contains divalent cobalt complex. This is because when the trivalent cobalt complex is mixed with the hole transport material, the hole transport material is oxidized and the cobalt complex becomes divalent. In other words, in the present invention, it is preferable that the photoelectric conversion layer further contains divalent cobalt complex. In particular, it is particularly preferable that almost no trivalent cobalt complex remains in the hole transport layer of the photoelectric conversion element, and almost all cobalt complexes are divalent. As a result, not only can the hole transport property be improved and stabilized, the high output and its sustainability be improved, but also the effect can be further exerted even in a low temperature environment.

[0135] Regarding the valence of the cobalt complex contained in the hole transport layer, for example, it can be clarified by performing XAFS analysis. XAFS analysis is an abbreviation of X-ray Absorption Fine Structure and is also called X-ray absorption fine structure analysis. For example, an XAFS spectrum can be obtained by irradiating a sample with X-rays and measuring the absorption amount. In the XAFS spectrum, the structure near the absorption edge is called XANES (X-ray Absorption Near Edge Structure), and the wide-area X-ray absorption fine structure appearing on the higher energy side by about 100 eV or more from the absorption edge is called EXAFS (Extended X-ray Absorption Fine Structure). However, information regarding the valence and structure of the atom of interest can be mainly obtained from the former XANES. In this case, for example, the XAFS spectra of divalent and trivalent cobalt complex powders are separately measured and compared with the XAFS spectrum of the cobalt complex contained in the hole transport layer, whereby the valence of the cobalt complex contained in the hole transport layer can be clarified. Figure 18 shows the results of obtaining the XAFS spectrum as described above for the photoelectric conversion element (Example 1) of the present invention. As shown in Figure 18, the cobalt complex contained in the hole transport layer of an example of the photoelectric conversion element of the present invention is in good agreement with the divalent cobalt complex powder, and there is no part that coincides with the trivalent cobalt complex powder. Therefore, it can be judged that almost all of the contained cobalt complex is divalent.

[0136] As the trivalent cobalt complex added to the coating solution for forming the hole transport layer, the cobalt complexes represented by the following structural formulas (4) and (5) can be preferably used.

[0137]

Chemical formula

[0138]

Chemical formula

[0139]

Chemical formula

[0140] Regarding X, among the structural formulas (6) to (9), the structural formula (8) is more preferable. By using the structural formula (8), it is effective in that the hole transport material can be stably maintained in an oxidized state.

[0141] Specific examples of these cobalt complexes include (F-1) to (F-24) shown below. However, it is not limited thereto.

[0142]

Chemical formula

[0143] [Chem.]

[0144] [Chem.]

[0145] Among these, (F-18) and (F-23) are preferable.

[0146] --Hypervalent iodine compound-- The hypervalent iodine compound means a compound having iodine with 9 or more formal valence electrons exceeding the octet. In other words, the hypervalent iodine compound means a compound having more electrons than 8 required by the octet rule and containing an iodine atom in a hypervalent state. Here, the valence electron is also called the valence electron and means an electron that occupies the outer electron shell excluding the inner shell electrons in the electron configuration of an atom. The photoelectric conversion element can improve the durability and stability of the output by including a hypervalent iodine compound in the hole transport layer.

[0147] The hypervalent iodine compound that can be used in the present invention is not particularly limited and can be appropriately selected according to the purpose, but preferably contains at least one of a periodinane compound and a diaryliodonium salt. The periodinane compound and the diaryliodonium salt have high solubility in halogen solvents such as chlorobenzene and low crystallinity and acidity. Therefore, by including at least one of the periodinane compound and the diaryliodonium salt in the hole transport layer, the output of the photoelectric conversion element can be improved. Here, in the photoelectric conversion element, by reducing the acidity of the hole transport layer, the open-circuit voltage can be improved. Therefore, as the material used for the hole transport layer, a material with low acidity is preferable. As a method for reducing the acidity of the hole transport layer, for example, by increasing the proportion (content) of the basic material in the hole transport layer, the acidity of the hole transport layer can be lowered. However, in this case, the proportion of the hole transport compound in the hole transport layer will decrease. For this reason, when improving the open-circuit voltage by increasing the proportion of the basic material in the hole transport layer, the series resistance increases and the output at high illuminance light decreases. For the above reasons, when reducing the acidity of the hole transport layer, it is preferable to use a material that has high solubility in halogen-based solvents such as chlorobenzene, such as perjodinan compounds and diaryliodonium salts, and has low crystallinity and low acidity.

[0148] As the hypervalent iodine compound, in particular, the perjodinan compound represented by the following general formula (8) and the diaryliodonium salt represented by the following general formula (9) have been found to obtain high output when used as an oxidizing agent in the hole transport layer due to their high solubility, low crystallinity, and low acidity. When the acidity of the hole transport layer is high, the open-circuit voltage becomes low. By increasing the addition amount of the basic material, it is also possible to increase the open-circuit voltage. However, by reducing the concentration of the hole transport material, the series resistance increases and the output at high illuminance light decreases.

Chemical formula

Chemical formula

[0149] Specific examples of the periodinane compound represented by the general formula (8) and the diaryliodonium salt represented by the general formula (9) include, for example, (G-1) to (G-10) shown below. However, it is not limited thereto.

[0150] [Chemical formula]

[0151] [Chemical formula]

[0152] Other hypervalent iodine compounds of the following structural formulas may also be used.

[0153] [Chemical formula]

[0154] Also, it may contain a compound represented by the following general formula (10) as an oxidizing agent.

[0155] [Chemical formula] ···General formula (10) (In the general formula (10), R1 to R5 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and may be the same or different. X represents a cation.

[0156] Specific examples of the compound represented by the general formula (10) include, but are not limited to, the following (I-1) to (I-28).

[0157]

Chem.

[0158]

Chem.

[0159]

Chem.

[0160]

Chem.

[0161]

Chem.

[0162]

Chem.

[0163] The content of the oxidizing agent is preferably 0.5 parts by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less, based on 100 parts by mass of the hole transport material. It is not necessary for all of the hole transport material to be oxidized by the addition of the oxidizing agent, and it is effective if only a part of it is oxidized.

[0164] The hole transport layer may have a single-layer structure composed of a single material or a laminated structure containing a plurality of compounds. When the hole transport layer has a laminated structure, it is preferable to use a polymer material for the hole transport layer closer to the second electrode described later. Using a polymer material with excellent film-forming properties is advantageous in that it can make the surface of the porous electron transport layer smoother and improve the photoelectric conversion characteristics. In addition, since the polymer material is less likely to penetrate into the porous electron transport layer, it has excellent coating properties on the surface of the porous electron transport layer, and may also be effective in preventing short circuits when providing electrodes.

[0165] There is no particular limitation on the polymer material used for the hole transport layer, and examples include known hole-transporting polymer materials. Examples of the hole-transporting polymer material include polythiophene compounds, polyphenylene vinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, polythiadiazole compounds, and the like. 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-quarterthiophene), 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-bithiophene), and the like. Examples of the polyphenylene vinylene compound include poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene vinylene], poly[(2-methoxy-5-(2-ethylphenyloxy)-1,4-phenylene vinylene)-co-(4,4'-biphenylene-vinylene)], and the like. Examples of the polyfluorene compound 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)], poly[(9,9-dioctyl-2,7-diyl)-co-(1,4-(2,5-dihexyloxy)benzene)], and the like. Examples of the polyphenylene compound include poly[2,5-dioctyloxy-1,4-phenylene], poly[2,5-di(2-ethylhexyloxy-1,4-phenylene)], and the like. 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[(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], poly(3,4-didecylthiophene-co-(1,4-benzo(2,1',3)thiadiazole), and the like. Among these, from the viewpoints of carrier mobility and ionization potential, polythiophene compounds and polyarylamine compounds are preferred.

[0166] Various additives may be added to the hole transport material. Examples of the additive include metal iodides such as iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, and silver iodide; quaternary ammonium salts such as tetraalkylammonium iodide and pyridinium iodide; metal bromides such as lithium bromide, sodium bromide, potassium bromide, cesium bromide, and calcium bromide; bromine salts of quaternary ammonium compounds such as tetraalkylammonium bromide and pyridinium bromide; metal chlorides such as copper chloride and silver chloride; metal acetates such as copper acetate, silver acetate, and palladium acetate; metal sulfates such as copper sulfate and zinc sulfate; metal complexes such as ferrocyanide-ferricyanide and ferrocene-ferricinium ion; sulfur compounds such as sodium polysulfide and alkylthiol-alkyldisulfide; viologen dyes, hydroquinone, etc.; ionic liquids described in Inorg. Chem. 35 (1996) 1168 such as 1,2-dimethyl-3-n-propylimidazolinium iodide, 1-methyl-3-n-hexylimidazolinium iodide, 1,2-dimethyl-3-ethylimidazolium trifluoromethanesulfonate, 1-methyl-3-butylimidazolium nonafluorobutylsulfonate, and 1-methyl-3-ethylimidazolium bis(trifluoromethyl)sulfonylimide; basic compounds such as pyridine, 4-t-butylpyridine, benzimidazole, or derivatives thereof; and alkali metal salts, etc.

[0167] The average thickness of the hole transport layer is not particularly limited and can be appropriately selected according to the purpose. However, it preferably has a structure that penetrates into the pores of the porous electron transport layer. On the electron transport layer, it 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 still more preferably 0.2 μm or more and 2 μm or less.

[0168] The hole transport layer can be formed directly on the electron transport layer described later on which the photosensitizing compound is adsorbed. As a method for producing the hole transport layer, the amount (remaining amount) of chlorobenzene after forming the photoelectric conversion element is 30 μg / mm 3There is no particular limitation as long as it can be made as follows, and it can be appropriately selected according to the purpose. Examples include methods for forming a thin film in a vacuum such as the vacuum evaporation method, and wet film formation methods. Among these, the wet film formation method is particularly preferable in terms of manufacturing cost and the like, and a method of coating on the electron transport layer is preferable. When using the wet film formation method, the coating method is not particularly limited and can be carried out according to known methods. For example, dip coating, spray coating, wire bar coating, spin coating, roller coating, blade coating, gravure coating, die coating, and as wet printing methods, various methods such as letterpress, offset, gravure, intaglio, rubber plate, screen printing, etc. can be used.

[0169] Also, film formation may be carried out in a supercritical fluid or a subcritical fluid at a temperature and pressure lower than the critical point. The supercritical fluid exists as a non-aggregating high-density fluid in the temperature and pressure region beyond the limit (critical point) where gas and liquid can coexist, and does not aggregate even when compressed. As long as it is a fluid in a state above the critical temperature and above the critical pressure, there is no particular limitation and it can be appropriately selected according to the purpose, but those with a low critical temperature are preferable.

[0170] Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, ether solvents, etc. Examples of the alcohol solvent include methanol, ethanol, n-butanol, etc. Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene, etc. Examples of the halogen solvent include methylene chloride, chlorotrifluoromethane, etc. Examples of the ether solvent include dimethyl ether, etc. These may be used alone or in combination of two or more. Among these, since carbon dioxide has a critical pressure of 7.3 MPa and a critical temperature of 31°C, it can easily create a supercritical state and is preferable in that it is nonflammable and easy to handle.

[0171] The subcritical fluid is not particularly limited as long as it exists as a high-pressure liquid in the temperature and pressure regions near the critical point, and can be appropriately selected according to the purpose. Compounds listed as supercritical fluids can also be suitably used as subcritical fluids.

[0172] The critical temperature and critical pressure of the supercritical fluid are not particularly limited and can be appropriately selected according to the purpose. However, as the critical temperature, -273°C or higher and 300°C or lower is preferable, and 0°C or higher and 200°C or lower is more preferable.

[0173] Furthermore, in addition to the supercritical fluid and the subcritical fluid, an organic solvent or an entrainer can also be used in combination. By adding an organic solvent and an entrainer, the solubility in the supercritical fluid can be adjusted more easily. The organic solvent is not particularly limited as long as it contains chlorobenzene, and can be appropriately selected according to the purpose. For example, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, hydrocarbon solvents, etc. can be mentioned. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate, etc. Examples of the ether solvent include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane, etc. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc. Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene, and the like. 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, cumene, and the like. These may be used alone or in combination of two or more.

[0174] In addition, as a method for producing the hole transport layer, it is preferable to apply a hole transport layer forming material containing a material for forming the hole transport layer onto an electron transport layer adsorbed with a photosensitizing compound and then dry and control it before forming the second electrode, and it is particularly preferable to perform heat drying. The pressure under the conditions of the heat drying is not particularly limited, but it is preferably performed under normal pressure. The temperature under the conditions of the heat drying is preferably 30°C or higher and 130°C or lower, and more preferably 50°C or higher and 100°C or lower. The treatment time under the conditions of the heat drying is preferably 10 minutes or longer and 24 hours or shorter, and more preferably 30 minutes or longer and 2 hours or shorter.

[0175] In addition, after laminating a hole transport material on an electron transport layer adsorbed with a photosensitizing compound, a pressing treatment step may be performed. By performing the pressing treatment, the hole transport material adheres more closely to the electron transport layer which is a more porous electrode, and thus the efficiency may be improved in some cases. The method of the pressing treatment is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include a press molding method using a flat plate such as an IR tablet molding machine, a roll press method using a roller, and the like. The pressure is preferably 10 kgf / cm 2 or more, and 30 kgf / cm2 The above is more preferable. The time for the pressing treatment is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 1 hour or less. Also, heat may be applied during the pressing treatment. During the pressing treatment, a release agent may be sandwiched between the press machine and the electrode.

[0176] Examples of the release agent include fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, ethylene tetrafluoride - hexafluoropropylene copolymer, perfluoroalkoxyfluoride resin, polyvinylidene fluoride, ethylene - tetrafluoroethylene copolymer, ethylene - chlorotrifluoroethylene copolymer, and polyvinyl fluoride. These may be used alone or in combination of two or more.

[0177] After performing the pressing treatment step, before providing the second electrode, a metal oxide may be provided between the hole transport material and the second electrode. Examples of the metal oxide 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 preferable. The method for providing the metal oxide on the hole transport layer is not particularly limited and can be appropriately selected according to the purpose, and examples include methods for forming a thin film in a vacuum such as sputtering method and vacuum evaporation method, and wet film - forming methods.

[0178] As the wet film - forming method, it is preferable to prepare a paste in which a powder or sol of a metal oxide is dispersed and apply it on the hole transport layer. The coating method when using the wet film - forming method is not particularly limited and can be carried out according to known methods. For example, dipping method, spraying method, wire - bar method, spin - coating method, roller - coating method, blade - coating method, gravure - coating method, die - coating method, and as wet printing methods, 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 0.1 nm or more and 50 nm or less, more preferably 1 nm or more and 10 nm or less.

[0179] <Second electrode> The second electrode can be formed on the hole transport layer or on the metal oxide in the hole transport layer. Also, the same material as the first electrode can be used for the second electrode, and the second substrate is not necessarily required if the strength is sufficiently maintained.

[0180] Examples of the material of the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers. Examples of the metal include platinum, gold, silver, copper, and aluminum. Examples of the carbon compound include graphite, fullerene, carbon nanotube, 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.

[0181] Regarding the formation of the second electrode, depending on the type of material used and the type of hole transport layer, it can be formed on the hole transport layer by appropriate methods such as coating method, lamination method, evaporation method, CVD method, and bonding method. In the photoelectric conversion element of the present invention, at least one of the first electrode and the second electrode is preferably substantially transparent. A method in which the first electrode side is transparent and incident light is incident from the first electrode side is preferred. In this case, it is preferable to use a material that reflects light on the second electrode side, and a metal, glass, plastic, or metal thin film on which a conductive oxide is deposited is preferably used. Also, providing an antireflection layer on the incident light side is an effective means.

[0182] <Second substrate> The second substrate is not particularly limited, and known substrates can be used. For example, substrates such as glass, plastic film, and ceramic can be mentioned. In order to improve the adhesion at the joint between the second substrate and the sealing member, uneven portions may be formed. The method for forming the uneven portions is not particularly limited and can be appropriately selected according to the purpose. For example, sandblasting, water blasting, abrasive paper, chemical etching, laser processing, etc. can be mentioned.

[0183] As a means for improving the adhesion between the second substrate and the sealing member, for example, organic substances on the surface may be removed, or hydrophilicity may be improved. The means for removing organic substances on the surface of the second substrate is not particularly limited and can be appropriately selected according to the purpose. For example, UV ozone cleaning, oxygen plasma treatment, etc. can be mentioned.

[0184] <<Sealing member>> The photoelectric conversion element of the present invention can 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, which is effective. In other words, in the present invention, it is preferable to further have a sealing member that shields the photoelectric conversion layer from the external environment of the photoelectric conversion element. As the sealing member, any conventionally known member can be used as long as it can reduce the intrusion of excessive moisture, oxygen, etc. from the external environment into the sealed interior. Further, the sealing member also has the effect of preventing mechanical destruction due to being pressed from the outside, and any conventionally known member can be used as long as this can be realized.

[0185] The sealing method can be roughly classified into "frame sealing", in which a sealing member is provided at the peripheral edge of the power generation region formed by the photoelectric conversion layer of the photoelectric conversion element and adhered to the second substrate, and "surface sealing", in which a sealing member is provided over the entire surface of the power generation region and adhered to the second substrate. The former "frame sealing" can form a hollow portion inside the seal, so it is possible to appropriately adjust the amount of moisture and oxygen inside the seal. Also, since the second electrode is not in contact with the sealing member, there is an effect of reducing the influence of electrode peeling. On the other hand, the latter "surface sealing" is excellent in preventing the intrusion of excessive water and oxygen from the outside, and since the adhesion area with the sealing member is large, the sealing strength is high, and it is particularly suitable when a flexible substrate is used for the first substrate.

[0186] There are no particular restrictions on the type of the sealing member, and it can be appropriately selected according to the purpose. For example, cured resins and low melting point glass resins can be mentioned. As the cured resin, there are no particular restrictions as long as it is a resin that cures by light or heat, and it can be appropriately selected according to the purpose. Among them, acrylic resins and epoxy resins are preferably used.

[0187] Any known material can be used for the cured product of the acrylic resin as long as it is a cured product of a monomer or oligomer having an acrylic group in the molecule. Any known material can be used for the cured product of the epoxy resin as long as it is a cured product of a monomer or oligomer having an epoxy group in the molecule. Examples of the epoxy resin include a water dispersion type, a solvent-free type, a solid type, a heat-curing type, a curing agent mixed type, an ultraviolet curing type, etc. Among these, the heat-curing type and the ultraviolet curing type are preferred, and the ultraviolet curing type is more preferred. Note that even in the case of the ultraviolet curing type, heating is possible, and it is preferable to perform heating even after ultraviolet curing. Examples of the epoxy resin include bisphenol A type, bisphenol F type, novolak type, cycloaliphatic type, long-chain aliphatic type, glycidylamine type, glycidyl ether type, glycidyl ester type, etc. These may be used alone or in combination of two or more.

[0188] It is preferable to mix a curing agent and various additives with the epoxy resin as necessary. The curing agents are classified into amine-based, acid anhydride-based, polyamide-based, and other curing agents, and are appropriately selected according to the purpose. Examples of the amine-based curing agents include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of the acid anhydride-based curing agents include phthalic anhydride, tetra- and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, het anhydride, and dodecenyl succinic anhydride. Examples of the other curing agents include imidazoles and polymercaptans. These may be used alone or in combination of two or more.

[0189] Examples of the additives include fillers, gap agents, polymerization initiators, desiccants (humidity absorbers), curing accelerators, coupling agents, plasticizers, colorants, flame retardant aids, antioxidants, and organic solvents. Among these, fillers, gap agents, curing accelerators, polymerization initiators, and desiccants (humidity absorbers) are preferable, and fillers and polymerization initiators are more preferable.

[0190] The filler is effective in suppressing the intrusion of moisture and oxygen, and can also obtain effects such as reduction of volume shrinkage during curing, reduction of outgassing amount during curing or heating, improvement of mechanical strength, and control of thermal conductivity and fluidity, which is very effective for maintaining stable output in various environments. In particular, the output characteristics and durability of the photoelectric conversion element are not only affected by the intrusion of moisture and oxygen, but also by the outgassing generated during the curing or heating of the sealing member, which cannot be ignored. In particular, the influence of outgassing generated during heating has a great impact on the output characteristics during storage in a high-temperature environment. In this case, by incorporating a filler, a gap filler, and a desiccant into the sealing member, these substances themselves can suppress the ingress of moisture and oxygen, and the amount of the sealing member used can be reduced, thereby obtaining the effect of reducing outgassing. This is effective not only during curing but also when the photoelectric conversion element is stored in a high-temperature environment.

[0191] There are no particular restrictions on the filler, and it can be appropriately selected according to the purpose. 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 can be used alone or in combination of two or more. The average primary particle size of the filler is preferably 0.1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. When the addition amount is within the preferred range, the effect of suppressing the ingress of moisture and oxygen can be sufficiently obtained, the viscosity becomes appropriate, and it is also effective for improving the adhesion to the substrate, defoaming property, controlling the width of the sealing portion, and workability.

[0192] As the content of the filler, based on 100 parts by mass of the entire sealing member, it 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. When the content of the filler is within the above range, the effect of suppressing the ingress of moisture and oxygen can be sufficiently obtained, the viscosity is also appropriate, and the adhesion and workability are also good.

[0193] The gap filler, also referred to as a gap control agent or a spacer agent, can control the gap of the sealing portion. For example, when applying a sealing member on the first substrate or the first electrode and placing the second substrate thereon for sealing, by mixing a gap filler into the epoxy resin, the gap of the sealing portion can be easily controlled to match the size of the gap filler. As the gap filler, known materials can be used as long as they are granular, have a uniform particle size, and have high solvent resistance and heat resistance. Those having high affinity with the epoxy resin and a spherical particle shape are preferred. Specifically, glass beads, silica fine particles, organic resin fine particles, etc. are mentioned. These may be used alone or in combination of two or more. The average particle size of the gap filler can be selected according to the gap of the sealing part 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.

[0194] Examples of the polymerization initiator include a thermal polymerization initiator that initiates polymerization using heat, a photopolymerization initiator that initiates polymerization using light, and the like. The thermal polymerization initiator is a compound that generates active species such as radicals and cations by heating. Specifically, azo compounds such as 2,2'-azobisbutyronitrile (AIBN) and peroxides such as benzoyl peroxide (BPO) are used. As the thermal cationic polymerization initiator, benzenesulfonic acid ester, alkylsulfonium salt, etc. are used. On the other hand, in the case of an epoxy resin, a photo cationic polymerization initiator is preferably used as the photopolymerization initiator. When a photo cationic polymerization initiator is mixed with an epoxy resin and light irradiation is performed, the photo cationic polymerization initiator decomposes to generate a strong acid, and the acid causes the polymerization of the epoxy resin, and the curing reaction proceeds. The photo cationic polymerization initiator has effects such as less volume shrinkage during curing, no oxygen inhibition, and high storage stability. Examples of the photo cationic polymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metallocene compounds, silanol-aluminum complexes, and the like.

[0195] In addition, a photoacid generator having a function of generating an acid by irradiating light can also be used. The photoacid generator acts as an acid that initiates cationic polymerization. Examples thereof include onium salts such as ionic sulfonium salt-based and iodonium salt-based composed of a cationic part and an anionic part. These may be used alone or in combination of two or more. The addition amount of the polymerization initiator may vary depending on the materials used. However, it is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 5 parts by mass or less, based on 100 parts by mass of the entire sealing member. When the addition amount is within the above range, curing proceeds properly, the residual amount of uncured material can be reduced, and the generation of excessive outgas can be prevented, which is effective.

[0196] The desiccant, also referred to as a moisture absorbent, is a material having a function of physically or chemically adsorbing and absorbing moisture. Incorporating it into the sealing member can be effective in further enhancing the moisture resistance and reducing the influence of outgas in some cases. The desiccant is preferably in particulate form, 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 sieve, and zeolite. Among these, zeolite and calcium oxide with a large moisture absorption amount are preferred. These may be used alone or in combination of two or more.

[0197] The curing accelerator, also referred to as a curing catalyst, is used for the purpose of accelerating the curing rate 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), imidazole-based compounds 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.

[0198] The coupling agent has the effect of enhancing the molecular binding force, 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, 3-methacryloxypropyltrimethoxysilane and other silane coupling agents. These may be used alone or in combination of two or more.

[0199] Furthermore, as the sealing member, an epoxy resin composition commercially available as a sealing material, a sealing material or an adhesive is known, and can also be effectively used in the present invention. Among them, there are also epoxy resin compositions developed and commercially available for use in solar cells and organic EL elements, and can be particularly effectively used in the present invention. For example, TB3118, TB3114, TB3124, TB3125F (manufactured by Three Bond Co., Ltd.), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyodo Chemical Co., Ltd.), WB90US(P) (manufactured by Moresco Co., Ltd.) and the like can be mentioned. Examples of the commercially available products of the acrylic resin include, for example, product names: TB3035B, TB3035C (both manufactured by Three Bond Co., Ltd.), NICHIBAN UM (manufactured by Nichiban Co., Ltd.) and the like. These sealing members can be heat-treated after being cured by irradiation with ultraviolet rays or the like, and are effective in the present invention. By performing the heat treatment, it may be possible to reduce the amount of uncured components, which is effective in reducing the amount of outgas that affects the output characteristics, enhancing the sealing performance, and enhancing the output characteristics and their sustainability.

[0200] On the one hand, after the low melting point glass resin is fired after resin coating, the resin component is decomposed, and then while being melted by an infrared laser or the like, it is sealed by being brought into close contact with the glass substrate. At this time, the low melting point glass component diffuses into the interior of the metal oxide layer and is physically joined, so that high sealing performance can be obtained. Further, since the resin component has disappeared and no outgas is generated like an ultraviolet curable resin, it is effective for improving the durability of the photoelectric conversion element. Generally, it is commercially available as glass frit or glass paste, and these can be used effectively. In the present invention, a lower melting point one is preferable.

[0201] The heat treatment temperature is not particularly limited and can be freely set according to the sealing member to be used, but it is preferably 50°C or higher and 200°C or lower, more preferably 60°C or higher and 150°C or lower, and even more preferably 70°C or higher and 100°C or lower. The heat treatment time is not particularly limited and can be freely set according to the sealing member to be used, but it is preferably 10 minutes or longer and 10 hours or shorter, more preferably 20 minutes or longer and 5 hours or shorter, and even more preferably 30 minutes or longer and 3 hours or shorter.

[0202] In the present invention, a sheet-like sealing material can also be effectively used. The sheet-like sealing material is one in which a resin layer is previously formed on a sheet, and the sheet is made of glass, a film having high gas barrier properties, or the like, and corresponds to the second substrate in the present invention. By attaching the sheet-like sealing material onto the second electrode of the photoelectric conversion element and then curing it, the sealing member and the substrate can be formed at once. If the resin layer formed on the sheet is formed over the entire surface, it becomes "surface sealing", but depending on the formation pattern of the resin layer, it can also be made into "frame sealing" in which a hollow portion is provided inside the photoelectric conversion element. By containing oxygen in the hollow part inside the seal, it becomes possible to stably maintain the hole transport function of the hole transport layer over a long period, which may be effective for improving the durability of the photoelectric conversion element. In the present invention, the oxygen concentration in the hollow part inside the seal provided by sealing can obtain an effect if oxygen is contained, but it is more preferably 5.0% by volume or more and 21.0% by volume or less, and further preferably 10.0% by volume or more and 21.0% by volume or less.

[0203] The oxygen concentration in the hollow part can be controlled by performing the sealing in a glove box with the oxygen concentration adjusted. The adjustment of the oxygen concentration can be performed by a method using a gas cylinder having a specific oxygen concentration or a method using a nitrogen gas generator. The oxygen concentration in the glove box can be measured using a commercially available oxygen concentration meter or oxygen monitor. The measurement of the oxygen concentration in the hollow part formed by sealing can be performed by, for example, in-package moisture and residual gas analysis (IVA) or atmospheric pressure ionization mass spectrometer (API-MS). Specifically, the photoelectric conversion element is installed in a chamber filled with a high vacuum or an inert gas, the seal is opened in the chamber, and the gas and moisture in the chamber are mass-analyzed to quantify all components in the gas contained in the hollow part and calculate the ratio of oxygen to the total sum, thereby obtaining the oxygen concentration.

[0204] As the gas other than oxygen contained inside the seal, an inert gas is preferable, and nitrogen, argon, etc. are preferable. When performing the sealing, it is preferable to control the dew point together with the oxygen concentration in the glove box, which is effective for improving the output and its durability. The dew point is defined as the temperature at which condensation starts when a gas containing water vapor is cooled. The dew point is not particularly limited, but is preferably 0°C or lower, and more preferably -20°C or lower. As the lower limit, -50°C or higher is preferable.

[0205] The method for forming the sealing portion is not particularly limited and can be carried out according to known methods. For example, various methods such as the dispensing method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, letterpress, offset, intaglio, rubber plate, screen printing, etc. can be used.

[0206] 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 the sealing member is arranged so as not to contact the second electrode, and can be appropriately selected according to the purpose. However, aluminum oxide, silicon nitride, silicon oxide, etc. are preferably used.

[0207] Hereinafter, an example of the photoelectric conversion element of the present invention will be described with reference to the drawings. However, the present invention is not limited thereto. For example, regarding the number, position, shape, etc. of the following constituent members that are not described in this embodiment, they are also included in the scope of the present invention.

[0208] <First Embodiment> FIG. 1 is a schematic diagram showing an example of the photoelectric conversion element of the first embodiment. In the photoelectric conversion element 101 of the first embodiment shown in FIG. 1, a first electrode 2 is formed on a first substrate 1. As shown in FIG. 1, in the photoelectric conversion element 101, a first electrode 2 is formed on a first substrate 1, and a hole blocking layer 3 is formed on the first electrode 2. An electron transport layer 4 is formed on the hole blocking layer 3, and a photosensitizing compound 5 is adsorbed on the surface of the electron transporting material constituting the electron transport layer 4. A hole transport layer 6 is formed above 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 sealed by a sealing member 8 between it and the hole blocking layer 3. The photoelectric conversion element shown in Fig. 1 can have a hollow portion 10 between the second electrode 7 and the second substrate 9. By having the hollow portion, the oxygen concentration in the hollow portion can be controlled, so that the power generation performance and durability can be further improved. Further, since the second electrode 7 and the second substrate 9 do not directly contact each other, it is possible to prevent the second electrode 7 from peeling or breaking. Although not shown, the first electrode 2 and the second electrode 7 can each have a path leading to the electrode extraction terminal.

[0209] <Second Embodiment> Fig. 2 is a schematic view showing an example of the photoelectric conversion element of the second embodiment. The photoelectric conversion element 101 of the second embodiment in Fig. 2 shows the case where the hollow portion is not provided and the hollow portion in Fig. 2 is covered with the sealing member 8. The method for manufacturing a photoelectric conversion element without providing a hollow portion is not particularly limited and can be appropriately selected according to the purpose. For example, a method of applying the sealing member 8 to the entire surface on the second electrode 7 and providing the second substrate 9 thereon, or a method using the above-mentioned sheet-like sealing material can be mentioned. As the hollow portion inside the seal, it may be completely eliminated or a part of the hollow portion may be left. By covering almost the entire surface with the sealing member, when stress is applied to the photoelectric conversion element due to twisting or dropping, etc., the second substrate 9 can be prevented from peeling or breaking, and the mechanical strength of the photoelectric conversion element can be increased. It is also possible to provide a buffer layer between the second electrode 7 and the sealing member 8. As a modified example of Fig. 2, as shown in Fig. 3, a configuration without providing the second substrate may be adopted.

[0210] (Method for Manufacturing Photoelectric Conversion Element) The method for manufacturing the photoelectric conversion element of the present invention is a photoelectric conversion layer forming step of forming a photoelectric conversion layer having a hole transport layer on a first electrode, a heating and drying step of heating and drying the hole transport layer, and includes other steps as necessary.

[0211] The manufacturing method of the photoelectric conversion element of the present invention includes the steps of forming a first electrode on a first substrate, forming a photoelectric conversion layer on the first electrode, forming a second electrode on the photoelectric conversion layer, and further disposing other members such as a hole blocking layer and a sealing member as required.

[0212] In the manufacturing method of the photoelectric conversion element of the present invention, the first electrode, the photoelectric conversion layer, the second electrode, and other members and layers are the same as those described in the photoelectric conversion element of the present invention.

[0213] In the manufacturing method of the photoelectric conversion element of the present invention, the hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine. It has been found that by the hole transport layer containing a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine, a high output can be obtained even with low-intensity light, and the output variation over time is small, and a photoelectric conversion element capable of obtaining a stable output can be obtained.

[0214] <Photoelectric conversion layer forming step> The photoelectric conversion layer forming step is a step of forming a photoelectric conversion layer having a hole transport layer on the first electrode. The photoelectric conversion layer forming step is a step of forming a photoelectric conversion layer by the same method as described for the photoelectric conversion layer in the photoelectric conversion element of the present invention.

[0215] <Heating and drying step> The heating and drying step is a step of heating and drying the formed hole transport layer. By performing the heating and drying step, the solvent contained in the layer (film) made of the coating solution for forming the hole transport layer is volatilized. As the conditions for heating and drying in the heating and drying step, it is preferably 30°C or higher and 130°C or lower, and 10 minutes or longer and 24 hours or shorter under normal pressure, and more preferably 50°C or higher and 100°C or lower, and 30 minutes or longer and 2 hours or shorter under normal pressure.

[0216] As the method for performing the above-mentioned heat drying, there is no particular limitation as long as the conditions for heat drying described above can be achieved, and it can be appropriately selected according to the purpose. For example, the following methods can be mentioned. Any conventionally known method such as an oven, a dryer, a thermostat, a hot plate, etc. can be used.

[0217] (Photovoltaic conversion module) In the photovoltaic conversion module of the present invention, a plurality of the photovoltaic conversion elements of the present invention are provided, and the adjacent photovoltaic conversion elements are electrically connected in series or in parallel. The photovoltaic conversion module of the present invention has, for example, a photovoltaic conversion element arrangement region in which a plurality of photovoltaic conversion elements are arranged adjacent to each other and are connected in series or in parallel, and a photovoltaic conversion layer including an electron transport layer and a hole transport layer is formed between the first electrode and the second electrode for the plurality of photovoltaic conversion elements.

[0218] In the photovoltaic conversion module of the present invention, the plurality of the photovoltaic conversion elements of the present invention are electrically connected in series or in parallel.

[0219] The photovoltaic conversion module of the present invention has, for example, a photovoltaic conversion element arrangement region in which a plurality of photovoltaic conversion elements are arranged adjacent to each other and are connected in series or in parallel, and a photovoltaic conversion layer including an electron transport layer and a hole transport layer is formed between the first electrode and the second electrode for the plurality of photovoltaic conversion elements.

[0220] The photovoltaic conversion module of the present invention can be configured to have a plurality of the photovoltaic conversion elements. Further, the plurality of photovoltaic conversion elements may be connected in series and / or in parallel, or may include independent photovoltaic conversion elements that are not connected.

[0221] As the configuration of each layer of the photovoltaic conversion module, the same configuration as that of the photovoltaic conversion element can be adopted.

[0222] The structure of the photoelectric conversion module is not particularly limited and can be appropriately selected according to the purpose. However, 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, thereby reducing the risk of short circuit. 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 to each other.

[0223] Further, in at least two adjacent photoelectric conversion elements of the photoelectric conversion module, the first electrode in one photoelectric conversion element and the second electrode in the other photoelectric conversion element may be electrically connected by a conduction portion penetrating at least from the hole transport layer to the hole blocking layer.

[0224] The photoelectric conversion module can have a configuration in which it has a pair of substrates and has a photoelectric conversion element arrangement region connected in series or in parallel between the pair of substrates, and the sealing member is sandwiched between the pair of substrates. That is, it is preferable to have a sealing member that shields the hole transport layer of the plurality of arranged photoelectric conversion elements constituting the photoelectric conversion module from the external environment of the photoelectric conversion module.

[0225] Hereinafter, an example of the photoelectric conversion element module of the present invention will be described with reference to the drawings. However, the present invention is not limited to these. For example, regarding the number, position, shape, etc. of the following constituent members that are not described in this embodiment mode, they are also included in the scope of the present invention.

[0226] <Fourth Embodiment> FIG. 4 is a schematic view showing an example of the photoelectric conversion element module of the present invention, and is an example showing a partial cross section of a photoelectric conversion element module including a plurality of photoelectric conversion elements connected in series. FIG. 4 shows that after forming the hole transport layer 6, the through-hole 12 is formed, and then the second electrode 7 is formed, so that the second electrode material is introduced into the through-hole 12 and can be electrically connected to the first electrode 2b of the adjacent cell. Although not shown in FIG. 4, the first electrode 2a and the second electrode 7b further have a path that conducts to the electrodes of the adjacent photoelectric conversion elements or the output extraction terminals.

[0227] The through-hole 12 may penetrate the first electrode 2 and reach the first substrate 1, or the processing may stop inside the first electrode 2 and may not reach the first substrate 1. When the shape of the through-hole 12 is a micropore that penetrates the first electrode 2 and reaches the first substrate 1, if the total opening area of the micropores becomes too large with respect to the area of the through-hole 12, the film cross-sectional area of the first electrode 2 decreases, resulting in an increase in the resistance value and a possible decrease in the photoelectric conversion efficiency. Therefore, the ratio of the total opening area of the micropores to the area of the through-hole 12 is preferably 5 / 100 or more and 60 / 100 or less.

[0228] The method for forming the through-hole 12 is not particularly limited and can be appropriately selected according to the purpose. Examples include the sandblasting method, the water blasting method, abrasive paper, the chemical etching method, the laser processing method, etc. Among these, the laser processing method is preferred. Thereby, fine holes can be formed without using sand, etching, resist, etc., and it is possible to perform clean and reproducible processing. Further, when forming the through-hole 12, at least one of the hole blocking layer 3, the electron transport layer 4, the hole transport layer 6, and the second electrode 7 can be removed by impact peeling by the laser processing method. Thereby, it is not necessary to provide a mask during lamination, and removal and formation of the fine through-hole 12 can be simply performed at once.

[0229] <Fifth Embodiment> FIG. 5 is a schematic diagram showing an example of the photoelectric conversion element module of the present invention. Different from FIG. 4, the hole transport layer 6 is separated from the adjacent photoelectric conversion element, and each has an independent layer structure. Thereby, electron diffusion is suppressed, the leakage current is reduced, and the durability may be further improved, which is effective.

[0230] (Electronic device) The electronic device of the present invention includes any one of the photoelectric conversion element of the present invention and the photoelectric conversion module of the present invention, and a device that operates by the electric power generated by the photoelectric conversion of the photoelectric conversion element or the photoelectric conversion module, and further includes other devices as needed. Further, the electronic device of the present invention includes any one of the photoelectric conversion element of the present invention and the photoelectric conversion module of the present invention, a power storage device capable of storing the electric power generated by the photoelectric conversion of the photoelectric conversion element or the photoelectric conversion module, and a device that operates by the electric power stored in the power storage device, and further includes other devices as needed.

[0231] (Power supply module) The power supply module of the present invention includes the photoelectric conversion module of the present invention and a power supply circuit (IC; Integrated Circuit), and further includes other devices as needed.

[0232] Next, a specific embodiment of the photoelectric conversion module of the present invention and an electronic device having a device that operates by the electric power obtained by generating electricity thereof will be described.

[0233] FIG. 6 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 FIG. 6, a photoelectric conversion module, a power supply IC, and a power storage device are combined, and the supplied electric power is connected to the power supply of the control circuit of the mouse. Thereby, when the mouse is not in use, the power storage device can be charged, and the mouse can be operated with the electric power, and a mouse that does not require wiring or battery replacement can be obtained. Further, since the battery is not required, the weight can be reduced, which is effective.

[0234] FIG. 7 is a schematic external view showing an example of the mouse shown in FIG. 6. As shown in FIG. 7, the photoelectric conversion module, the power supply IC, and the power storage device are mounted inside the mouse. However, the upper part of the photoelectric conversion element of the photoelectric conversion module is covered with a transparent housing so that light hits the photoelectric conversion element. Further, it is also possible to mold the entire housing of the mouse with a transparent resin. The arrangement of the photoelectric conversion elements is not limited to this. For example, even when the mouse is covered with a hand, it can be arranged at a position where light is irradiated, and there may be a preferable case.

[0235] Next, another embodiment of the photoelectric conversion module of the present invention and an electronic device having a device that operates by the electric power obtained by generating power thereof will be described.

[0236] FIG. 8 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 FIG. 8, the photoelectric conversion element of the photoelectric conversion module, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the control circuit of the keyboard. Thereby, it is possible to charge the power storage device when the keyboard is not in use and operate the keyboard with the power, and a keyboard that does not require wiring or battery replacement can be obtained. Further, since the battery becomes unnecessary, weight reduction is also possible, which is effective.

[0237] FIG. 9 is a schematic external view showing an example of the keyboard shown in FIG. 8. As shown in FIG. 9, the photoelectric conversion element of the photoelectric conversion module, the power supply IC, and the power storage device are mounted inside the keyboard. However, the upper part of the photoelectric conversion element is covered with a transparent housing so that light hits the photoelectric conversion element. It is also possible to mold the entire housing of the keyboard with a transparent resin. The arrangement of the photoelectric conversion elements is not limited to this. In the case of a small keyboard with a small space for incorporating the photoelectric conversion element, as shown in FIG. 10, it is also possible to embed a small photoelectric conversion element in a part of the key, which is effective.

[0238] Next, another embodiment of an electronic device having the photoelectric conversion module of the present invention and a device that operates by the electric power obtained by their power generation will be described.

[0239] FIG. 11 is a block diagram of a sensor as an example of the electronic device of the present invention. As shown in FIG. 11, the photoelectric conversion element, power supply IC, and power storage device of the photoelectric conversion module are combined, and the supplied power is connected to the power supply of the sensor circuit. As a result, it is possible to configure a sensor module without the need to connect to an external power supply or replace the battery. As sensing targets, it can be applied to various sensors such as temperature and humidity, illuminance, human presence, CO2, acceleration, UV, noise, geomagnetism, and atmospheric pressure, and is effective. As shown in FIG. 12, the sensor module is configured to periodically sense a measurement target and wirelessly transmit the read data to a PC, smartphone, or the like.

[0240] With the advent of the IoT (Internet of Things) society, the number of sensors is expected to increase rapidly. It is extremely laborious and unrealistic to replace the batteries of these countless sensors one by one. In addition, the sensors are also in places where it is difficult to replace the batteries, such as on the ceiling or wall, which deteriorates the workability. The ability to supply power by the photoelectric conversion element is also a very great merit. In addition, the photoelectric conversion module of the present invention can obtain a high output even at low illuminance, and since the light incident angle dependence of the output is small, there is also an advantage of high installation freedom.

[0241] Next, another embodiment of an electronic device having the photoelectric conversion module of the present invention and a device that operates by the electric power obtained by their power generation will be described.

[0242] FIG. 12 is a block diagram of a turntable as an example of the electronic device of the present invention. As shown in Fig. 12, 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. As a result, it is possible to configure the turntable without the need to connect to an external power supply or replace the battery. The turntable is used, for example, in a showcase for displaying products. However, the power supply wiring looks unsightly, and when replacing the battery, the displayed items must be removed, which is very troublesome. By using the photoelectric conversion module of the present invention, such problems can be solved, which is effective.

[0243] As described above, the photoelectric conversion module of the present invention, the electronic device having the device operated by the power obtained by generating power by these, and the power supply module have been described. However, these are only a small part, and the photoelectric conversion module of the present invention is not limited to these applications.

[0244] <Usage> The photoelectric conversion module of the present invention can function as a self-powered power supply, and it is possible to operate the device using the power generated by photoelectric conversion. Since the photoelectric conversion module of the present invention can generate power when irradiated with light, there is no need to connect the electronic device to a power supply or replace the battery. Therefore, it is possible to operate the electronic device even in a place without power supply equipment, carry it around on the body, or operate the electronic device without replacing the battery even in a place where it is difficult to replace the battery. Also, when using dry batteries, the electronic device becomes heavier and larger accordingly, which may hinder installation on a wall or ceiling or carrying. However, the photoelectric conversion module of the present invention is lightweight and thin, so the degree of freedom of installation is high, and it has great advantages in wearing and carrying around.

[0245] Thus, the photoelectric conversion module of the present invention can be used as an independent power source and can be combined with various electronic devices. For example, it can be combined with desktop calculators, wristwatches, mobile phones, electronic notebooks, display devices such as electronic paper, peripheral devices of personal computers 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, remote controls, and many other electronic devices for use. Since the photoelectric conversion module of the present invention can generate electricity even with light of particularly low illuminance, it can generate electricity indoors and even in darker shaded areas, so its application range is wide. Also, it has no liquid leakage like dry batteries and is highly safe as there is no risk of accidental ingestion like button batteries. Furthermore, it can be used as an auxiliary power source to extend the continuous usage time of rechargeable or dry battery-powered electrical appliances. Thus, by combining the photoelectric conversion module of the present invention with a device that operates using the electricity generated by its photoelectric conversion, an electronic device can be reborn that is lightweight, easy to use, has a high degree of installation freedom, does not require replacement, is highly safe, and is also effective in reducing environmental impact.

[0246] Fig. 13 shows a basic configuration diagram of an electronic device combining the photoelectric conversion module of the present invention with a device that operates using the electricity generated by its photoelectric conversion. When light irradiates the photoelectric conversion element, electricity is generated and can be extracted. The circuit of the device can be made to operate using that electricity. However, since the output of the photoelectric conversion element of the photoelectric conversion module changes depending on the ambient illuminance, the electronic device shown in Fig. 13 may not be able to operate stably. In this case, as shown in Fig. 14, in order to supply a stable voltage to the circuit side, it is possible and effective to incorporate a power supply IC for the photoelectric conversion element between the photoelectric conversion element and the circuit of the device.

[0247] However, the photoelectric conversion element of the photoelectric conversion module can generate electricity if it is irradiated with light of sufficient illuminance. However, when the illuminance is insufficient for power generation, the desired power cannot be obtained, which is also a drawback of the photoelectric conversion element. In this case, as shown in Fig. 15, by mounting a power storage device such as a capacitor between the power supply IC and the device circuit, it becomes possible to charge the surplus power from the photoelectric conversion element to the power storage device. Even when the illuminance is too low or when the photoelectric conversion element is not irradiated with light, it becomes possible to supply the power stored in the power storage device to the device circuit, enabling stable operation. Thus, in an electronic device combining the photoelectric conversion module of the present invention and a device circuit, by combining a power supply IC and a power storage device, it can operate even in an environment without power supply, battery replacement is unnecessary, and it can be stably driven, maximizing the advantages of the photoelectric conversion element.

[0248] On the other hand, the photoelectric conversion module of the present invention can also be used as a power supply module and is useful. For example, as shown in Fig. 16, when the photoelectric conversion module of the present invention is connected to a power supply IC for the 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 to the power supply IC at a certain voltage level.

[0249] Furthermore, as shown in Fig. 17, 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 to the power storage device, and a power supply module that can supply power can be configured even when the illuminance is too low or when the photoelectric conversion element is not irradiated with light. The power supply module of the present invention shown in Figs. 16 and 17 can be used as a power supply module without replacing the battery like a conventional primary battery.

Example

[0250] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments at all.

[0251] (Example 1) <Fabrication of a photoelectric conversion element> On a glass substrate as the first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) as the first electrode were sequentially formed by sputtering. Next, a dense layer made of titanium oxide as a hole blocking layer was formed by reactive sputtering with oxygen gas. Next, 3 parts by mass of titanium oxide (ST-21, manufactured by Ishihara Sangyo Co., Ltd.), 0.2 parts by mass of acetylacetone, and 0.3 parts by mass of polyoxyethylene octylphenyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) as a surfactant were subjected to bead mill treatment for 12 hours together with 5.5 parts by mass of water and 1.0 part by mass of ethanol. Then, 1.2 parts by mass of polyethylene glycol (polyethylene glycol 20,000, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the obtained titanium oxide dispersion to prepare a paste. The prepared paste was applied onto the hole blocking layer (average thickness: about 1.2 μm), dried at 110°C, and then fired in air at 550°C for 30 minutes to form a porous electron transport layer. The glass substrate on which the electron transport layer was formed was immersed in a mixed solution composed of the photosensitizing compound represented by B-5 and acetonitrile / t-butanol (volume ratio 1:1), and allowed to stand in the dark for 1 hour. Then, the excess photosensitizing compound was removed, and the photosensitizing compound was adsorbed on the surface of the electron transport layer. Next, 1550 parts by mass of chlorobenzene was added with 28.3 parts by mass of lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (LiFTFSI) (manufactured by PROVISCO CS) as a lithium salt, 50.0 parts by mass of the pyridine compound of the tertiary amine represented by C-11, 5.5 parts by mass of the pyridine compound of the secondary amine represented by C-24 (10% by mass based on the total amount of the pyridine compounds), 274 parts by mass of the hole transport material represented by D-7 (manufactured by Merck KGaA), 26.2 parts by mass of the trivalent cobalt complex represented by F-11 (manufactured by Sigma-Aldrich Japan K.K.) as an oxidizing agent, and 86 parts by mass of acetonitrile (manufactured by Kanto Chemical Co., Inc.), and they were dissolved to prepare a coating solution for the hole transport layer. Next, on the electron transport layer adsorbed with the photosensitizing compound, the coating solution for the hole transport layer was used to form a hole transport layer by die coating (average thickness: about 550 nm). Thereafter, the hole transport layer coated on the outer edge of the glass substrate was removed, and silver was vacuum-deposited on the hole transport layer to form a second electrode (average thickness: 80 nm). Next, on the outer edge of the glass substrate from which the hole transport layer was removed, an ultraviolet curable resin (World Rock No. 5910, manufactured by Kyoritsu Chemical Industry Co., Ltd.) as a sealing member was applied using a dispenser (2300N, manufactured by Sun Atec Co., Ltd.) so as to surround the power generation region. Thereafter, it was transferred into a glove box into which a nitrogen mixed gas with an oxygen concentration of 15% (dew point: -60°C) was introduced, a cover glass as a second substrate was placed on the ultraviolet curable resin, the resin was cured by ultraviolet irradiation to seal the power generation region, and finally heat treatment was performed at 80°C for 1 hour to fabricate the photoelectric conversion element of Example 1 shown in FIG. 1.

[0252] (Example 2) (Fabrication of Photoelectric Conversion Module) On a glass substrate as a first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) as a first electrode were sequentially formed by sputtering. Next, a dense layer made of titanium oxide was formed as a hole blocking layer by reactive sputtering with oxygen gas. Next, a part of the first electrode and the hole blocking layer formed on the substrate was etched by laser processing, and a part between adjacent cells was divided by an insulation patterning process. Next, in the same manner as in Example 1, an electron transport layer was formed. Subsequently, the electron transport layer was etched by laser processing to divide between adjacent cells. Next, a photosensitizing compound was adsorbed on the surface of the electron transport layer in the same manner as in Example 1. Furthermore, a coating solution for forming a hole transport layer was prepared in the same manner as in Example 1, and using this, a hole transport layer was formed on the electron transport layer by dip coating (average thickness: about 550 nm). Thereafter, the outer edge portion of the glass substrate on which the sealing member is provided was etched by laser processing, and further, a through hole for connecting the photoelectric conversion elements in series was formed by laser processing. Furthermore, silver was vacuum-deposited thereon to form a second electrode (average thickness: about 80 nm). At this time, silver was also deposited on the inner wall of the through hole, and it was confirmed that adjacent cells were connected in series. Next, an ultraviolet curable resin (WorldRock No. 5910, manufactured by Kyoryaku Chemical Industry Co., Ltd.) as a sealing member was applied to the outer edge portion of the glass substrate so as to surround the power generation region using a dispenser (2300N, manufactured by Sun-A Tech Co., Ltd.). Thereafter, it was transferred into a glove box into which a nitrogen mixed gas with an oxygen concentration of 15% (dew point: -60°C) was introduced, a cover glass as a second substrate was placed on the ultraviolet curable resin, the resin was cured by ultraviolet irradiation, and further heat treatment was performed at 80°C for 1 hour to fabricate a photoelectric conversion module shown in FIG. 5.

[0253] (Example 3) In the preparation of the coating solution for the hole transport layer of Example 2, except that it was changed to 52.4 parts by mass of a pyridine compound of a tertiary amine and 2.8 parts by mass of a pyridine compound of a secondary amine (5% by mass based on the total amount of the pyridine compounds), a photoelectric conversion module of Example 3 was fabricated in the same manner as in Example 2.

[0254] (Example 4) In the preparation of the coating liquid for the hole transport layer of Example 2, except that 54.6 parts by mass of the pyridine compound of the tertiary amine and 0.6 part by mass of the pyridine compound of the secondary amine (1% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 4 was produced in the same manner as in Example 2.

[0255] (Example 5) In the preparation of the coating liquid for the hole transport layer of Example 2, except that 46.9 parts by mass of the pyridine compound of the tertiary amine and 8.3 parts by mass of the pyridine compound of the secondary amine (15% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 5 was produced in the same manner as in Example 2.

[0256] (Example 6) In the preparation of the coating liquid for the hole transport layer of Example 2, except that 44.1 parts by mass of the pyridine compound of the tertiary amine and 11.0 parts by mass of the pyridine compound of the secondary amine (20% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 6 was produced in the same manner as in Example 2.

[0257] (Example 7) In the preparation of the coating liquid for the hole transport layer of Example 2, except that the materials corresponding to the following materials were changed as follows, a photoelectric conversion module of Example 7 was produced in the same manner as in Example 2. · Lithium salt 29.9 parts by mass · Pyridine compound of the tertiary amine represented by C-13 49.5 parts by mass · Pyridine compound of the secondary amine represented by C-25 5.5 parts by mass (10% by mass based on the total amount of the pyridine compounds) · Trivalent cobalt complex represented by F-22 (manufactured by Sigma-Aldrich Japan K.K.) 25.5 parts by mass

[0258] (Example 8) In the preparation of the coating liquid for the hole transport layer of Example 7, except that 44.0 parts by mass of a pyridine compound of a tertiary amine and 11.0 parts by mass of a pyridine compound of a secondary amine (20% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 8 was produced in the same manner as in Example 7.

[0259] (Example 9) In the preparation of the coating liquid for the hole transport layer of Example 7, except that 41.25 parts by mass of a pyridine compound of a tertiary amine and 13.75 parts by mass of a pyridine compound of a secondary amine (25% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 8 was produced in the same manner as in Example 7.

[0260] (Example 10) In Example 2, except that the photosensitizing compound was changed to the photosensitizing compound represented by B1-10, and in the preparation of the coating liquid for the hole transport layer, the following materials were changed as follows for the corresponding materials, a photoelectric conversion module of Example 10 was produced in the same manner as in Example 2. · Lithium salt 31.3 parts by mass · Pyridine compound of tertiary amine 48.9 parts by mass · Pyridine compound of secondary amine 5.4 parts by mass (10% by mass based on the total amount of the pyridine compounds) · Trivalent cobalt complex represented by F-11 (manufactured by Sigma-Aldrich Japan K.K.) 27.6 parts by mass

[0261] (Example 11) In the preparation of the coating liquid for the hole transport layer of Example 10, except that 46.2 parts by mass of a pyridine compound of a tertiary amine and 8.2 parts by mass of a pyridine compound of a secondary amine (15% by mass based on the total amount of the pyridine compounds) were changed, a photoelectric conversion module of Example 11 was produced in the same manner as in Example 10.

[0262] (Example 12) In the preparation of the coating solution for the hole transport layer of Example 11, a photoelectric conversion module of Example 12 was fabricated in the same manner as in Example 11, except that the materials corresponding to the following materials were changed as follows. · Lithium salt: 27.8 parts by mass of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) (Tokyo Chemical Industry) · Tertiary amine pyridine compound represented by C-11: 48.1 parts by mass · Secondary amine pyridine compound represented by C-25: 7.2 parts by mass (13% by mass based on the total amount of the pyridine compound) · Trivalent cobalt complex represented by F-11 (manufactured by Sigma-Aldrich Japan K.K.): 26.2 parts by mass

[0263] (Example 13) In the preparation of the coating solution for the hole transport layer of Example 12, a photoelectric conversion module of Example 13 was fabricated in the same manner as in Example 12, except that the materials corresponding to the following materials were changed as follows. · Tertiary amine pyridine compound represented by C-12: 45.9 parts by mass · Secondary amine pyridine compound represented by C-23: 9.4 parts by mass (17% by mass based on the total amount of the pyridine compound) · Hole transport material represented by D-10: 274 parts by mass · Trivalent cobalt complex represented by F-11 (manufactured by Sigma-Aldrich Japan K.K.): 26.2 parts by mass

[0264] (Comparative Example 1) In the preparation of the coating solution for the hole transport layer of Example 12, a photoelectric conversion module of Comparative Example 1 was fabricated in the same manner as in Example 12, except that 55.3 parts by mass of the tertiary amine pyridine compound was used and no secondary amine pyridine compound was added.

[0265] (Comparative Example 2) In the preparation of the coating liquid for the hole transport layer of Example 12, a photoelectric conversion module of Comparative Example 2 was produced in the same manner as in Example 12, except that no pyridine compound of a tertiary amine was added and 55.3 parts by mass of the pyridine compound of a secondary amine was used (100% by mass based on the total amount of the pyridine compound).

[0266] <Durability Test of Photoelectric Conversion Element and Photoelectric Conversion Module> For each of the produced photoelectric conversion elements and photoelectric conversion modules, the IV characteristics were evaluated using a solar cell evaluation system (As-510-PV03, manufactured by NF Circuit Design Block Co., Ltd.) under white LED irradiation adjusted to 200 lux, and the initial maximum output power Pmax (μW / cm 2 ) was determined. Next, the photoelectric conversion element and the photoelectric conversion module were irradiated for 150 hours under white LED irradiation adjusted to 10,000 lux, and then the IV characteristics were evaluated again under white LED irradiation adjusted to 200 lux, and the maximum output power Pmax2 (μW / cm 2 ) after the test was determined. Furthermore, the photoelectric conversion element and the photoelectric conversion module were irradiated for 450 hours (total 600 hours) under white LED irradiation adjusted to 10,000 lux, and then the IV characteristics were evaluated again under white LED irradiation adjusted to 200 lux, and the maximum output power Pmax2 (μW / cm 2 ) after the test was determined. Finally, the maximum output power Pmax2 (μW / cm 2 ) after the test was divided by the initial maximum output power Pmax1 (μW / cm 2 ) to obtain the Pmax retention rate (Pmax2 / Pmax1×100) after 150 hours and 600 hours of the durability test. These results are shown in Table 1.

[0267]

Table 1

[0268] As can be seen from the above results, it was found that by including two types of pyridine compounds, a tertiary amine and a secondary amine, in the hole transport layer, fluctuations in output were suppressed from the start of the durability test, enabling stable power generation. On the other hand, as shown in Comparative Example 1, when the secondary amine was not included, the output at the 150-hour mark significantly dropped, and although it recovered thereafter, it was found that the stability of power generation over time decreased. Also, as shown in Comparative Example 2, it was found that when only the pyridine compound of the secondary amine was included, the durability significantly decreased.

[0269] Examples of 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, wherein the photoelectric conversion layer has a hole transport layer, and the hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine. <2> The photoelectric conversion element according to <1>, wherein the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine are pyridine compounds represented by the following general formula (1).

Chemical formula

Chemical formula

[0270] The photoelectric conversion element according to any one of <1> to <9> above, the photoelectric conversion module according to any one of <10> to <12> above, the electronic device according to any one of <13> to <14> above, and the method for manufacturing a photoelectric conversion element according to <15> above can solve various conventional problems and achieve the object of the present invention.

Prior Art Documents

Patent Documents

[0271]

Patent Document 1

Explanation of Reference Numerals

[0272] 1 First substrate 2, 2a, 2b First electrode 3 Hole-blocking layer 4 Electron transport layer 5 Photosensitizing compound 6 Hole transport layer 7, 7a, 7b Second electrode 8 Sealing member 9 Second substrate 10 Hollow portion 11 Passivation layer 12 Through portion (conductive portion) 101 Photoelectric conversion element 102 Photoelectric conversion module

Claims

1. A first electrode, a photoelectric conversion layer, and a second electrode, wherein the photoelectric conversion layer has a hole transport layer, the hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine, the pyridine compound of the tertiary amine is any of the pyridine compounds represented by the following (C-11) to (C-13), the pyridine compound of the secondary amine is any of the pyridine compounds represented by the following (C-23) to (C-25), and the photoelectric conversion element is characterized by this. 【Chemical 1】

2. A first electrode, a photoelectric conversion layer, and a second electrode, wherein the photoelectric conversion layer has a hole transport layer, the hole transport layer contains a pyridine compound of a tertiary amine and a pyridine compound of a secondary amine, the combination of the pyridine compound of the tertiary amine and the pyridine compound of the secondary amine is any of the following (1) to (3), and the photoelectric conversion element is characterized by this. (1) A pyridine compound of a tertiary amine represented by the following (C-11) and a pyridine compound of a secondary amine represented by the following (C-24) or the following (C-25). (2) A pyridine compound of a tertiary amine represented by the following (C-12) and a pyridine compound of a secondary amine represented by the following (C-23). (3) A pyridine compound of a tertiary amine represented by the following (C-13) and a pyridine compound of a secondary amine represented by the following (C-25). [Chemical 2]

3. The content of the pyridine compound of the secondary amine is 20% by mass or less based on the total amount of the pyridine compounds, and the photoelectric conversion element according to any one of Claims 1 to 2 is characterized by this.

4. the hole transport layer further contains an organic hole transport material, the organic hole transport material contains a spiro-type compound, and the photoelectric conversion element according to any one of Claims 1 to 3 is characterized by this.

5. the hole transport layer further contains a lithium salt represented by the following general formula (2), and the photoelectric conversion element according to any one of Claims 1 to 4 is characterized by this. [Chemical Formula 3] ... General formula (2) However, in the general formula (2), A and B represent any one of the substituents of F, CF ３ , C ２ F ５ , C ３ F ７ , and C ４ F ９ , and the substituents of A and B are different.

6. the hole transport layer further contains an oxidizing agent, and the photoelectric conversion element according to any one of Claims 1 to 5 is characterized by this.

7. further having an electron transport layer, the electron transport layer contains titanium oxide fine particles having a photosensitizing compound adsorbed on the surface, and the photoelectric conversion element according to any one of Claims 1 to 6 is characterized by this.

8. The photoelectric conversion element according to claim 7, having a hole blocking layer between the first electrode and the electron transport layer.

9. The photoelectric conversion element according to any one of claims 1 to 8, having a sealing member that shields the hole transport layer from the external environment of the photoelectric conversion element.

10. A photoelectric conversion module, characterized in that the photoelectric conversion elements according to any one of claims 1 to 9 are 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 photoelectric conversion module according to claim 10, wherein the first electrode in one of the photoelectric conversion elements and the second electrode in the other photoelectric conversion element are electrically connected by a conduction part penetrating at least the hole transport layer and the electron transport layer.

12. The hole transport layer of the plurality of arranged photoelectric conversion elements constituting the photoelectric conversion module The photoelectric conversion module according to any one of claims 10 to 11, having a sealing member that shields from the external environment of the photoelectric conversion module.

13. At least one of the photoelectric conversion elements according to any one of claims 1 to 9 and the photoelectric conversion module according to any one of claims 10 to 12, An electronic device, characterized by having a device that operates by the electric power generated by the photoelectric conversion of the photoelectric conversion element or the photoelectric conversion module.

14. At least one of the photoelectric conversion elements according to any one of claims 1 to 9 and the photoelectric conversion module according to any one of claims 10 to 12, A power storage device capable of storing the electric power generated by the photoelectric conversion of at least one of the photoelectric conversion element and the photoelectric conversion module, An electronic device, characterized by having a device that operates by the electric power stored in the power storage device.

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