Photoelectric conversion element, photoelectric conversion module, electronic instrument and power module

Abstract

The present invention relates to a photoelectric conversion element, a photoelectric conversion module, an electronic device and a power module that can provide a high output even with low illumination and have excellent sustainability of the effect. The photoelectric conversion element comprises a first electrode, a photoelectric conversion layer and a second electrode, the photoelectric conversion layer comprises an electron transport layer and a hole transport layer, and the photoelectric conversion layer comprises a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3).

Description

Technical Field

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

[0002] In recent years, solar cells that can generate electricity efficiently even under low-illuminance light have attracted attention and are expected to have a wide range of applications, not only in terms of use regardless of installation location, but also as stand-alone power sources that do not require battery replacement or power wiring.

[0003] For example, amorphous silicon or organic solar cells are known as indoor photoelectric conversion elements. Even in organic solar cells, dye-sensitized solar cells have charge generation and charge transfer functions in separate layers, which is advantageous in that they can be easily manufactured. Generally, dye-sensitized solar cells contain electrolytes, which may cause volatilization or leakage of electrolytes. In recent years, solid-state dye-sensitized solar cells using p-type semiconductor materials have also been developed and attracted much attention.

[0004] Therefore, for the purpose of providing a photoelectric conversion element with high efficiency and high long-term stability, a photoelectric conversion element is proposed, which has a first electrode, an electron transport layer formed on the first electrode, a hole transport layer and a second electrode, and the electron transport layer includes an electron transport compound to carry a compound represented by the following general formula (1′) and a compound represented by the following general formula (2′) (for example, refer to patent document 1).

[0005] Chemical formula 1

[0006] (wherein X1 and X2 represent oxygen atoms, sulfur atoms or selenium atoms, R1 represents a methine, and R2 represents an alkane

[0007]

[0008] R3 represents an acidic group which may be the same or different, m represents 1 or 2, and Z1 and Z2 represent a group which forms a ring structure).

[0009] Chemical formula 2

[0010] R5-R4-COOH General formula (2')

[0011] (wherein R4 represents an aryl group or a heterocyclic group, and R5 represents an alkyl group, an alkoxy group, an alkenyl group, an alkylthio group or an aryl ether group).

[0012] An object of the present invention is to provide a photoelectric conversion element which can obtain high output even with light of low illumination and has excellent sustainability of the effect.

[0013] Patent Document 1: Japanese Patent Application Publication No. 2018-113437 Summary of the invention

[0014] As a means for solving the above-mentioned problem, the photoelectric conversion element of the present invention comprises a first electrode, a photoelectric conversion layer and a second electrode, wherein the photoelectric conversion layer comprises an electron transport layer and a hole transport layer, and the photoelectric conversion layer comprises a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3),

[0015] Chemical formula 3

[0016]

[0017] In the general formula (1), Ar1 and Ar2 represent an aryl group which may have a substituent, R1 and R2 represent a linear or branched alkyl group having 4 to 10 carbon atoms, and X represents an arbitrary substituent represented by the following structural formula:

[0018] Chemical formula 4

[0019]

[0020] Chemical formula 5

[0021]

[0022] In the above general formula (2), n represents an integer of 0 or 1, and R3 represents an aryl group which may have a substituent or any substituent represented by the following structural formula.

[0023] Chemical formula 6

[0024]

[0025] Chemical formula 7

[0026]

[0027] Wherein, in the general formula (3), A and B represent any substituent of F, CF3, C2F5, C3F7 and C4F9, and the substituents of A and B are different.

[0028] According to the present invention, it is possible to provide a photoelectric conversion element which can obtain high output even with light of low illumination and has excellent sustainability of its effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. 1 is a schematic diagram of a photoelectric conversion element according to the first embodiment.

[0030] Figure 2FIG. 1 is a schematic diagram showing an example of a photoelectric conversion element according to the second embodiment.

[0031] Figure 3 FIG. 1 is a schematic diagram showing an example of a photoelectric conversion element according to the third embodiment.

[0032] Figure 4 FIG. 1 is a schematic diagram showing an example of a photoelectric conversion element according to a fourth embodiment.

[0033] Figure 5 This is a block diagram of a personal computer mouse as an example of the electronic device of the present invention.

[0034] Figure 6 yes Figure 5 A schematic external view of an example of a mouse is shown.

[0035] Figure 7 This is a block diagram of a personal computer keyboard as an example of the electronic device of the present invention.

[0036] Figure 8 yes Figure 7 A schematic external view of an example of a keyboard is shown.

[0037] Fig. 9 yes Figure 7 A schematic external view of another example of a keyboard is shown.

[0038] Fig.10 This is a block diagram of a sensor as an example of the electronic device of the present invention.

[0039] Fig.11 This is a block diagram of a turntable as an example of the electronic device of the present invention.

[0040] Fig.12 This is a block diagram of an example of the electronic device of the present invention.

[0041] Fig.13 is Fig.12 The electronic device shown is further equipped with a power supply IC as a module.

[0042] Fig.14 is Fig.13 The electronic device shown is further equipped with a module example of a power storage device.

[0043] Fig.15 Shown is a module example of the power module of the present invention.

[0044] Fig.16 is Fig.15 An example of a module in which a power module is further integrated with an electric storage device is shown.

[0045] Specific implementation form

[0046] (Photoelectric conversion element)

[0047] The photoelectric conversion element refers to an element capable of converting light energy into electric energy, and is applied to a solar cell, a photodiode, or the like.

[0048] The photoelectric conversion element has a first electrode, a photoelectric conversion layer and a second electrode, wherein the photoelectric conversion layer has an electron transport layer and a hole transport layer, and further has other members such as a first substrate, a second substrate, a hole blocking layer and a sealing member as required.

[0049] In the prior art, dyes related to photosensitizing compounds represented by the following general formula (1) are disclosed, but lithium salts represented by the following general formula (3) are not described, and there is a problem that the sustainability of output characteristics is insufficient.

[0050] In the present invention, the photoelectric conversion element comprises a first electrode, a photoelectric conversion layer and a second electrode, wherein the photoelectric conversion layer comprises an electron transport layer and a hole transport layer. By comprising a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3), a photoelectric conversion element can be obtained which can obtain a high output even with light of low illumination and has an excellent sustainability of effect.

[0051] Chemical formula 8

[0052]

[0053] In the general formula (1), Ar1 and Ar2 represent an aryl group which may have a substituent. R1 and R2 represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents an arbitrary substituent represented by the following structural formula.

[0054] Chemical formula 9

[0055]

[0056] Chemical formula 10

[0057]

[0058] In the above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent or any substituent represented by the following structural formula.

[0059] Chemical formula 11

[0060]

[0061] Chemical formula 12

[0062]

[0063] Wherein, in the general formula (3), A and B represent any substituent of F, CF3, C2F5, C3F7 and C4F9, and the substituents of A and B are different.

[0064] <1st substrate>

[0065] The shape, structure and size of the first substrate are not particularly limited and may be appropriately selected according to the intended purpose.

[0066] The material of the first substrate is not particularly limited as long as it has light transmittance and insulation properties, and can be appropriately selected according to the purpose, for example, substrates such as glass, plastic film, and ceramics can be cited. As described later, in the case of a firing process including forming an electron transport layer, a substrate having heat resistance to the firing temperature is preferred. In addition, the first substrate is preferably flexible.

[0067] The substrate may be provided at either or both of the outermost portion on the first electrode side and the outermost portion on the second electrode side of the photoelectric conversion element.

[0068] Hereinafter, the outermost substrate provided on the first electrode side is referred to as a first substrate, and the outermost substrate provided on the second electrode side is referred to as a second substrate.

[0069] <First Electrode>

[0070] The shape and size of the first electrode are not particularly limited and may be appropriately selected according to the purpose.

[0071] The structure of the first electrode is not particularly limited and may be appropriately selected depending on the intended purpose. The first electrode may have a single-layer structure or a structure in which a plurality of materials are stacked.

[0072] The material of the first electrode is not particularly limited as long as it has transparency to visible light and conductivity, and can be appropriately selected according to the purpose. Examples thereof include transparent conductive metal oxides, carbon, and metals.

[0073] As transparent conductive metal oxides, for example, there can be listed 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.

[0074] Examples of carbon include carbon black, carbon nanotubes, graphene, and fullerene.

[0075] Examples of the metal include gold, silver, aluminum, nickel, indium, tantalum, and titanium.

[0076] These may be used alone or in combination of two or more. Among them, transparent conductive metal oxides having high transparency are preferred, and ITO, FTO, ATO, and NTO are more preferred.

[0077] The average thickness of the first electrode is not particularly limited and can be appropriately selected according to the purpose, preferably 5 nm to 100 μm, more preferably 50 nm to 10 μm. In addition, when the material of the first electrode is carbon or metal, the average thickness of the first electrode is preferably an average thickness that can obtain light transmittance.

[0078] The first electrode can be formed by a known method such as sputtering, vapor deposition, or spraying.

[0079] In addition, the first electrode is preferably formed on the first substrate, and a commercially available product in which the first electrode is previously formed on the first substrate and is integrated can be used.

[0080] Examples of integrated commercial products include FTO-coated glass, ITO-coated glass, zinc oxide, aluminum-coated glass, FTO-coated transparent plastic film, ITO-coated transparent plastic film, etc. Other integrated commercial products include transparent electrodes in which cations or anions with different valences are doped in tin oxide or indium oxide, or glass substrates on which metal electrodes having a light-transmitting structure such as a mesh or stripe are provided.

[0081] These may be used alone or in combination of two or more, mixed or laminated. In order to reduce the resistance value, a metal lead or the like may be used in combination.

[0082] Examples of the material of the metal lead wire include aluminum, copper, silver, gold, platinum, and nickel.

[0083] The metal lead can be formed on the substrate by, for example, vapor deposition, sputtering, pressure bonding, etc., and an ITO or FTO layer can be provided thereon for combined use.

[0084] <Photoelectric Conversion Layer>

[0085] The purpose of forming the photoelectric conversion layer is to convert light irradiated on the photoelectric conversion element into electricity. Specifically, photoelectric conversion is performed by absorbing the light irradiated by the light and transferring the generated electrons and holes to the first electrode or the second electrode. Therefore, the photoelectric conversion layer may include an electron transport layer for transporting electrons, a photosensitizing compound that absorbs light and generates charges, a hole transport layer for transporting holes, etc., and further, these layers may be stacked.

[0086] <<Electron Transport Layer>>

[0087] The electron transport layer is formed to transport electrons generated by the photosensitizing compound to the first electrode or the hole blocking layer described below. Therefore, the electron transport layer is preferably disposed adjacent to the first electrode or the hole blocking layer.

[0088] As the structure of the electron transport layer, there is no particular limitation and it can be appropriately selected according to the purpose, but in at least two mutually adjacent photoelectric conversion elements, it is preferred that the electron transport layers are not mutually extended. If the electron transport layers are not mutually extended, it is advantageous to improve the light durability because the electron diffusion is suppressed and the leakage current is reduced. In addition, as the structure of the electron transport layer, it can be either a continuous layer single layer or a multilayer stacked with multiple layers.

[0089] The electron transport layer contains an electron transport material and, if necessary, contains other materials.

[0090] The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose, but a semiconductor material is preferred.

[0091] The semiconductor material preferably has a fine particle shape and is formed into a porous film by bonding them. The photosensitizing compound is chemically or physically adsorbed on the surface of the semiconductor particles constituting the porous electron transport layer.

[0092] The semiconductor material is not particularly limited, and a known material can be used. Examples of the semiconductor material include elemental semiconductors, compound semiconductors, and compounds having a perovskite structure.

[0093] Examples of elemental semiconductors include silicon and germanium.

[0094] Examples of compound semiconductors include metal chalcogenides, specifically oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum, etc.; sulfides of cadmium, zinc, lead, silver, antimony, bismuth, etc.; selenides of cadmium, lead, etc.; tellurides of cadmium, etc. Other examples of compound semiconductors include phosphides of zinc, gallium, indium, cadmium, etc., gallium arsenide, copper-indium-selenide, copper-indium-sulfide, etc.

[0095] Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate.

[0096] Among them, oxide semiconductors are also preferred, and titanium oxide, zinc oxide, tin oxide, and niobium oxide are particularly preferred. When the electron transport material of the electron transport layer is titanium oxide, the conduction band is high, and a high open circuit voltage can be obtained. In addition, the refractive index is high, and a high short-circuit current is obtained through the light confinement effect. Furthermore, a high dielectric constant and high mobility are advantageous for obtaining a high fill factor.

[0097] The semiconductor material may be used alone or in combination of two or more. In addition, the crystal of the semiconductor material is not particularly limited and may be appropriately selected according to the purpose, and may be single crystal, polycrystalline, or amorphous.

[0098] As the number average particle diameter of the primary particles of semiconductor material, there is no particular restriction, can be suitably selected according to purpose, but is preferably more than 1nm and less than 100nm, more preferably more than 5nm and less than 50nm. In addition, also can mix or stack the semiconductor material bigger than number average particle diameter, by making the effect of incident light scattering, can improve conversion efficiency sometimes. Number average particle diameter at this moment is preferably more than 50nm and less than 500nm.

[0099] The average thickness of the electron transport layer is not particularly limited and can be appropriately selected according to the purpose, preferably 50 nm to 100 μm, more preferably 100 nm to 50 μm, and even more preferably 120 nm to 10 μm. If the average thickness of the electron transport layer is within the preferred range, the amount of photosensitizing compound per unit projected area can be fully ensured, and while maintaining a high light capture rate, the diffusion distance of the injected electrons is difficult to increase, which is beneficial for reducing the loss caused by charge recombination.

[0100] There is no particular limitation on the method for preparing the electron transport layer, and it can be appropriately selected according to the purpose, for example, methods for forming a thin film in a vacuum such as sputtering, wet film forming methods, etc. Among them, from the viewpoint of manufacturing cost, the wet film forming method is preferred, and more preferred is a method of preparing a paste in which a powder or sol of a semiconductor material is dispersed, and coating it on the first electrode as an electron collector electrode substrate or on the hole blocking layer.

[0101] The wet film-forming method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dip coating, spray coating, wire bar coating, spin coating, roll coating, blade coating, and gravure coating.

[0102] As the wet printing method, various methods such as letterpress, offset printing, gravure, intaglio, rubber printing, and screen printing can be used.

[0103] As a method for preparing a dispersion of semiconductor material, for example, there can be cited a method of mechanical pulverization using a known grinding device, etc. By this method, a dispersion of semiconductor material can be prepared by dispersing a particulate semiconductor material alone or a mixture of a semiconductor material and a resin in water or a solvent.

[0104] As the resin, for example, there can be mentioned polymers or copolymers of vinyl compounds formed from styrene, vinyl acetate, acrylate, methacrylate, etc., silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, polyester resins, cellulose ester resins, cellulose ether resins, polyurethane resins, phenolic resins, epoxy resins, polycarbonate resins, polyarylate resins, polyamide resins, polyimide resins, etc. These may be used alone or in combination of two or more.

[0105] Examples of the solvent include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents.

[0106] Examples of the alcohol solvent include methanol, ethanol, isopropanol, and α-terpineol.

[0107] Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0108] Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate.

[0109] Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane.

[0110] Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0111] Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, iodomethane, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0112] Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene.

[0113] These may be used alone or in combination of two or more.

[0114] In order to prevent re-aggregation of particles, an acid, a surfactant, a chelating agent, or the like may be added to a dispersion containing a semiconductor material or a paste containing a semiconductor material obtained by a sol-gel method or the like.

[0115] Examples of the acid include hydrochloric acid, nitric acid, and acetic acid.

[0116] Examples of the surfactant include polyoxyethylene octylphenyl ether and the like.

[0117] Examples of the chelating agent include acetylacetone, 2-aminoethanol, and ethylenediamine.

[0118] Furthermore, in order to improve film forming properties, adding a thickener is also an effective method.

[0119] Examples of the thickener include polyethylene glycol, polyvinyl alcohol, and ethyl cellulose.

[0120] After the semiconductor material is applied, in order to make the particles of the semiconductor material contact with electrons and improve the film strength and the adhesion to the substrate, it can be fired, irradiated with microwaves or electron beams, or irradiated with lasers. These treatments can be performed alone or in combination of two or more.

[0121] When the electron transport layer formed of a semiconductor material is fired, 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 melt. Therefore, it is preferably 30° C. to 700° C., and more preferably 100° C. to 600° C. In addition, the firing time is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10 minutes to 10 hours.

[0122] When the electron transport layer formed by the semiconductor material is subjected to microwave irradiation, the irradiation time is not particularly limited and can be appropriately selected according to the purpose, but is preferably less than 1 hour. At this time, it can be irradiated from the side where the electron transport layer is formed, or it can be irradiated from the side where the electron transport layer is not formed.

[0123] After firing the electron transport layer formed by the semiconductor material, in order to increase the surface area of ​​the electron transport layer and improve the electron injection efficiency from the photosensitizing compound to the semiconductor material described later, for example, chemical plating using an aqueous solution of titanium tetrachloride or a mixed solution with an organic solvent, or electrochemical plating using an aqueous solution of titanium trichloride can be performed.

[0124] The film obtained by sintering a semiconductor material with a diameter of tens of nm can be formed into a porous state. This nanoporous structure has a very high surface area, which can be represented by a roughness factor. The roughness factor is a numerical value representing the actual area of ​​the porous interior relative to the area of ​​the semiconductor particles coated on the first substrate. Therefore, the roughness factor is as large as possible, but from the relationship with the average thickness of the electron transport layer, it is preferably 20 or more.

[0125] Alternatively, the particles of the electron transport material may be doped with a lithium compound. Specifically, a solution of a bis(trifluoromethanesulfonylimide) lithium compound may be deposited on the particles of the electron transport material using spin coating or the like, followed by a sintering treatment.

[0126] The lithium compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluoromethanesulfonyl imide), lithium bis(fluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, lithium perchlorate, and lithium iodide.

[0127] <<Photosensitizing Compounds>>

[0128] The photosensitizer compound is adsorbed on the surface of the semiconductor material constituting the electron transport layer in order to further improve the output and the photoelectric conversion efficiency.

[0129] The photosensitizing compound is not particularly limited as long as it is a compound that is photoexcited by light irradiated onto the photoelectric conversion element, and can be appropriately selected according to the purpose, and contains at least one of the compound represented by the following general formula (1) and the compound represented by the following general formula (2). They can contain either one or both of the compound represented by the following general formula (1) and the compound represented by the following general formula (2).

[0130] Chemical formula 13

[0131]

[0132] In the general formula (1), Ar1 and Ar2 represent an aryl group which may have a substituent. R1 and R2 represent a linear or branched alkyl group having 4 to 10 carbon atoms. X represents an arbitrary substituent represented by the following structural formula.

[0133] Chemical formula 14

[0134]

[0135] Chemical formula 15

[0136]

[0137] In the above general formula (2), n represents an integer of 0 or 1. R3 represents an aryl group which may have a substituent or any substituent represented by the following structural formula.

[0138] Chemical formula 16

[0139]

[0140] Among the photosensitizing compounds represented by the above general formula (1), the compounds represented by the following general formula (4) are more preferable because they can obtain high output even under low illuminance light.

[0141] Chemical formula 17

[0142]

[0143] In the above general formula (4), Ar4 and Ar5 represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent, and Ar6 represents a phenyl group which may have a substituent or a thienyl group which may have a substituent.

[0144] Specific examples of the photosensitizing compounds represented by the general formula (1) and the general formula (4) are shown below, but the present invention is not limited to these.

[0145] Chemical formula 18

[0146]

[0147] Chemical formula 19

[0148]

[0149] Chemical formula 20

[0150]

[0151] Chemical formula 21

[0152]

[0153] Chemical formula 22

[0154]

[0155] Among the photosensitizing compounds represented by the above general formula (2), the compounds represented by the following general formula (5) are more preferable because they can obtain high output even under low illuminance light.

[0156] Chemical formula 23

[0157]

[0158] In the above general formula (5), n represents an integer of 0 or 1.

[0159] Specific examples of the photosensitizing compounds represented by the general formula (2) and the general formula (5) are shown below, but the present invention is not limited to these.

[0160] Chemical formula 24

[0161]

[0162] Chemical formula 25

[0163]

[0164] These photosensitizing compounds may contain only one kind or two or more kinds. In addition, it is well known that LED light sources use light sources with different tones such as warm colors, cool colors, and white colors, and the spectrum is different depending on the color tone. For example, when the color temperature is 3,000K, the 600nm area becomes relatively strong, becoming a yellow fluorescent color with red, and when the color temperature is 5,000K, it becomes a daylight color that is balanced overall. When the color temperature exceeds 6,500K, the 450nm area becomes relatively strong, becoming a white fluorescent color with bluish color. Therefore, it is preferred that a high output can be maintained even if the color temperature of the LED used is different.

[0165] The absorption spectrum of the photosensitizer used in the present invention is highly compatible with the wavelength spectrum of LED, and a high output can be obtained for LED light. In particular, the absorption spectrum of the photosensitizer represented by the general formula (1) has a high absorbance and a wide absorption region, and is effective in maintaining a high output even when the color temperature changes. In addition, since the absorption spectrum is highly compatible with a generally widely used LED light source with a color temperature of 5000K, a high output can be obtained.

[0166] In addition, by appropriately mixing the above-mentioned photosensitizing compounds, the matching with the LED light source can be further improved, which is effective. Furthermore, the color of the photoelectric conversion element itself basically reflects the color of the photosensitizing compound, and mixing the photosensitizing compound is also effective in adjusting its color tone.

[0167] As a method for adsorbing the photosensitizing compound on the surface of the semiconductor material of the electron transport layer, there can be used 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 the solution of the photosensitizing compound or the dispersion of the photosensitizing compound to the electron transport layer and adsorbing it, etc. In the case of a method of immersing the electron transport layer formed with the semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, a dipping method, a dip coating method, a roll coating method, an air knife method, etc. can be used.

[0168] In the case of a method of applying a solution or dispersion of a photosensitizing compound to the electron transport layer for adsorption, a wire bar method, a slide hopper method, an extrusion method, a curtain coating method, a spin coating method, a spray coating method, etc. can be used. Alternatively, adsorption can be carried out in a supercritical fluid such as carbon dioxide.

[0169] When the photosensitizing compound is adsorbed on the semiconductor material, a condensing agent may be used in combination.

[0170] The condensation agent may be any one that acts as a catalyst to physically or chemically bind the photosensitizing compound on the surface of the semiconductor material, or one that acts stoichiometrically to favorably shift the chemical equilibrium. Furthermore, a thiol or hydroxy compound may be added as a condensation aid.

[0171] Examples of the solvent in which the photosensitizing compound is dissolved or dispersed include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents.

[0172] Examples of the alcohol solvent include methanol, ethanol, and isopropanol.

[0173] Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0174] Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate.

[0175] Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane.

[0176] Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0177] Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, iodomethane, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0178] Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene.

[0179] These may be used alone or in combination of two or more.

[0180] Depending on the type of photosensitizing compound, it may be more effective to inhibit the aggregation of the compounds, so an aggregation dissociating agent may be used in combination. Examples of the aggregation dissociating agent include steroid compounds such as bile acid and chenodeoxycholic acid, long-chain alkyl carboxylic acids, or long-chain alkyl phosphonic acids.

[0181] The content of the aggregation dissociation agent is preferably 0.5 mol parts to 100 mol parts, more preferably 10 mol parts to 50 mol parts, based on 1 mol part of the photosensitizing compound.

[0182] The temperature at which the photosensitizer compound or the photosensitizer compound and the aggregation dissociation agent are adsorbed on the surface of the semiconductor material constituting the electron transport layer is preferably from -50°C to 200°C. The adsorption time is preferably from 5 seconds to 1,000 hours, more preferably from 10 seconds to 500 hours, and further preferably from 1 minute to 150 hours. The adsorption process is preferably carried out in a dark place. In addition, the adsorption process can be carried out after standing or while stirring.

[0183] The stirring method is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include methods using a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor, a disperser, and ultrasonic dispersion.

[0184] <<Hole Transport Layer>>

[0185] As long as the hole transport layer has the function of transporting holes, known materials can be used, 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 into a polymer matrix, a molten salt containing a redox couple, a solid electrolyte, an inorganic hole transport material, an organic hole transport material, etc. Among them, an electrolyte solution or a gel electrolyte can also be used, but a solid electrolyte is preferred, and an organic hole transport material is more preferred.

[0186] In the present invention, the hole transport layer contains a lithium salt represented by the following general formula (3).

[0187] Chemical formula 26

[0188]

[0189] Wherein, in the general formula (3), A and B represent any substituent of F, CF3, C2F5, C3F7 and C4F9, and the substituents of A and B are different.

[0190] As these lithium salts, for example, (fluorosulfonyl) (trifluoromethanesulfonyl) imide lithium (Li-FTFSI), (fluorosulfonyl) (pentafluoroethanesulfonyl) imide lithium (Li-FPFSI), (fluorosulfonyl) (nonafluorobutylsulfonyl) imide lithium (Li-FNFSI), (nonafluorobutylsulfonyl) (trifluoromethanesulfonyl) imide lithium (Li-NFTFSI), (pentafluoroethanesulfonyl) (trifluoromethanesulfonyl) imide lithium (Li-PFTFSI) and the like can be cited, among which (fluorosulfonyl) (trifluoromethanesulfonyl) imide lithium (Li-FTFSI) is particularly preferred. Among them, (fluorosulfonyl) (trifluoromethanesulfonyl) imide lithium (Li-FTFSI) is particularly preferred.

[0191] When the photoelectric conversion layer contains these lithium salts, it is very effective in improving the output under low-intensity light and further improving its sustainability. In addition, it can also achieve the effect of improving high-temperature storage resistance.

[0192] The lithium salt is characterized in that the anion species A and B are different and asymmetric. The reason for the above effect is believed to be that the anion species is asymmetric, which not only improves the solubility of the lithium salt and allows a larger amount to be contained, but also improves the compatibility of the lithium salt, improves the stability of the film, and can inhibit the occurrence of crystallization.

[0193] The method of adding the lithium salt is preferably to add it to the coating liquid for hole transport layer formation for coating, but the formed film does not necessarily have to be included in the hole transport layer, as long as it is included in the photoelectric conversion layer including the hole transport layer and the electron transport layer, it is included in the present invention. In addition, even in the case of coating with a hole transport layer forming coating liquid containing the above-mentioned lithium salt, the formed film does not need to be contained in the state of lithium salt, and can also be contained in the state of separation into lithium cations and anions. Specifically, it is clear that when the above-mentioned lithium salt is contained in the coating liquid for hole transport layer formation to form the hole transport layer, the lithium cations migrate to the electron transport layer, and the lithium cations contained in the electron transport layer are more than the lithium cations contained in the hole transport layer. On the other hand, it is clear that for anions, although a part of them migrate to the electron transport layer, they are contained in the hole transport layer more than the electron transport layer. In the present invention, it is preferred that the cations and anions of the lithium salt are separated, and different distribution states are formed respectively, and it is believed that by including them in the photoelectric conversion layer, the effect of the present invention can be obtained.

[0194] In addition to the above-mentioned lithium salts, lithium salts with other structures may also be contained. As these lithium salts, in addition to the above-mentioned lithium salts, the anion species may also be symmetrical, for example, bis (fluorosulfonyl) imide lithium (Li-FSI), bis (trifluoromethanesulfonyl) imide lithium (Li-TFSI), bis (pentafluoroethanesulfonyl) imide lithium (Li-BETI), bis (nonafluorobutylsulfonyl) imide lithium, etc. may be cited. In addition, cyclic imides such as (cyclohexafluoropropane) (disulfone) imide lithium may also be cited.

[0195] The content of the lithium salt is preferably 5 mol% to 50 mol%, more preferably 20 mol% to 35 mol%, relative to the hole transport material. When the content is within the above range, the output to low-illuminance light is high, and the output maintenance rate is improved and the durability is high.

[0196] In the hole transport layer, in order to obtain the function of transporting holes, a hole transport material or a p-type semiconductor material is contained. As the hole transport material or the p-type semiconductor material, a known organic hole transport compound is used. As specific examples thereof, oxadiazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, oxadiazole compounds, tetraarylbenzidine compounds, stilbene compounds, spiro compounds, etc. can be cited.

[0197] Among them, spiro compounds are more preferred.

[0198] As the spiro compound, a compound represented by the following general formula (8) is preferred.

[0199] Chemical formula 27

[0200]

[0201] Wherein, in the general formula (8), R 31 ~R 34 Each independently represents a substituted amino group such as dimethylamino, diphenylamino, naphthyl-4-tolylamino, etc.

[0202] Specific examples of the spiro compound include (D-1) to (D-20) shown below, but are not limited to these.

[0203] Chemical formula 28

[0204]

[0205] Chemical formula 29

[0206]

[0207] Chemical formula 30

[0208]

[0209]

[0210] Chemical formula 32

[0211]

[0212] Chemical formula 33

[0213]

[0214] Chemical formula 34

[0215]

[0216] These spiro compounds, in addition to having high Hall mobility, are torsionally bonded by two benzidine skeleton molecules, thus forming a spherical electron cloud, and the intermolecular jumping conductivity is good, thus showing excellent photoelectric conversion characteristics. In addition, since the solubility is also high, it is dissolved in various organic solvents, and is amorphous (amorphous material without a crystalline structure), so it is easy to be tightly filled into a porous electron transport layer. Further, since there is no light absorption characteristic of more than 450nm, it is possible to make the photosensitizer compound effectively absorb light, which is particularly preferred for solid dye-sensitized solar cells.

[0217] In the hole transport layer, in addition to the hole transport material and the lithium salt, an oxidant is preferably added. The inclusion of the oxidant can improve the hole transport property, thereby improving the output characteristics, durability, and stability.

[0218] As the oxidant, for example, tris(4-bromophenyl)ammonium hexachloroantimonate, silver hexafluoroantimonate, tetrafluoronitrous borate, silver nitrate, metal complexes, high-valent iodine compounds, etc. are included, among which metal complexes and high-valent iodine compounds are preferably used. When the oxidant is a metal complex or a high-valent iodine compound, it has high solubility in an organic solvent and can be added in large quantities, resulting in improved hole transport properties and excellent persistence of the effect.

[0219] Metal complexes are composed of metal cations, ligands, and anions.

[0220] Examples of metal cations include cations of chromium, manganese, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, gold, platinum, etc. Among them, cations of cobalt, iron, nickel, and copper are preferred, and cobalt complexes are more preferred.

[0221] The ligand preferably includes a 5-membered and / or 6-membered heterocyclic ring containing at least one nitrogen atom, which may have a substituent. Specific examples include the following, but the present invention is not limited to these.

[0222] Chemical formula 35

[0223]

[0224] Chemical formula 36

[0225]

[0226] Examples of anions include hydrogen ions (H - ), fluoride ion (F - ), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ), hydroxide ion (OH - ), cyanide ion (CN - ), nitrate ion (NO3 - ), nitrite ion (NO2 - ), hypochlorite ion (ClO - ), chlorite ion (ClO2 - ), chlorate ion (ClO3 - ), perchlorate ion (ClO4 - ), permanganate ion (MnO4 - ), acetate ion (CH3COO - ), bicarbonate 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 - ), dicyanamide ion (N(CN)2 - ), p-toluenesulfonate ion (TsO - ), trifluoromethyl sulfate ion (CF3SO2 - ), bis(trifluoromethylsulfonyl)amide ion (N(SO2CF3)2 - ), tetrahydroxyaluminate ion ([Al(OH)4] - or [Al(OH)4(H2O)2] - ), dicyanosilver(I) ion ([Ag(CN)2] - ), tetrahydroxychromate (III) ion ([Cr(OH)4] - ), tetrachloroaurate (III) ion ([AuCl4] - ), oxygen ions (O2- ), sulfide ion (S2 - ), peroxide ion (O2 2- ), sulfate ion (SO4 2- ), sulfite ion (SO3 2- ), thiosulfate ion (S2O3 2- ), carbonate ions (CO3 2- ), chromate ion (CrO4 2- ), dichromate ion (Cr2O7 2- ), hydrogen phosphate ion (HPO4 2- ), tetrahydroxyzinc(II) ion ([Zn(OH)4] 2- ), tetracyanozinc(II) ion ([Zn(CN)4] 2- ), copper(II) chloride ion ([CuCl4] 2- ), phosphate ion (PO4 3- ), hexacyanoferrate (III) ion ([Fe(CN)6] 3- ), di(thiosulfate)silver(I)ate ion ([Ag(S2O3)2] 3- ) and hexacyanoferrate (II) ion ([Fe(CN)6] 4- ) These may be used alone or in combination of two or more.

[0227] Among them, a tetrafluoroborate ion, a hexafluorophosphate ion, a tetracyanoborate ion, a bis(trifluoromethylsulfonyl)amide ion, and a perchlorate ion are preferred.

[0228] Among these metal complexes, trivalent cobalt complexes represented by the following structural formulae (8) and (9) are also preferred. When the metal complex is a trivalent cobalt complex, it is advantageous in that the hole transport material can be oxidized.

[0229] Chemical formula 37

[0230]

[0231] Chemical formula 38

[0232]

[0233] More preferred is a trivalent cobalt complex represented by the following general formula (6).

[0234] Chemical formula 39

[0235]

[0236] In the above general formula (6), R4 to R6 represent a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group or a trifluoromethyl group. X represents any one of the following structural formulas (1) to (4).

[0237] Chemical formula 40

[0238]

[0239] Preferred examples of these metal complexes include (F-1) to (F-20) shown below, but are not limited to these.

[0240]

[0241]

[0242] The content of the oxidant is preferably 1 mol % to 30 mol %, more preferably 5 mol % to 20 mol % relative to the hole transport material. By adding the oxidant, not all of the hole transport material needs to be oxidized, and it is effective as long as part of it is oxidized.

[0243] The oxidizing agent may be used alone or in combination of two or more. By using two or more of them in combination, the hole transport layer becomes difficult to crystallize, and high heat resistance can be obtained.

[0244] The hole transport layer preferably further contains a basic compound. The inclusion of the basic compound can increase the open circuit voltage, which is effective for improving the output.

[0245] As the basic compound, any material known in the art may be used as long as it is a material showing alkalinity, and compounds having a pyridine structure are particularly effective. The pyridine ring is represented by the following structural formula (6), and the compound having a pyridine structure is a compound containing at least one pyridine ring.

[0246] Chemical formula 43

[0247]

[0248] Among the compounds having these pyridine structures, basic compounds such as 4-dimethylaminopyridine (DMAP), 4-pyrrolidinylpyridine (PYP), 4-piperidinylpyridine (PPP), and tert-butylpyridine (TBP) are also preferably used. More preferably, the basic compound represented by the following general formula (7) is effective.

[0249] Chemical formula 44

[0250]

[0251] In the general formula (7), Ar7 and Ar8 represent an aryl group which may have a substituent.

[0252] As Ar7 and Ar8, for example, there can be mentioned a phenyl group, a naphthyl group, a biphenyl group, etc. As the substituent, for example, there can be mentioned an alkyl group, an alkoxy group, etc.

[0253] When the hole transport layer contains these basic compounds, in addition to the above-mentioned effects, the output stability of the photoelectric conversion element is improved, and in particular, the fluctuation of the output characteristics for low-illuminance light is reduced, which is also advantageous in enabling stable power generation.

[0254] Specific examples of the basic compound represented by the general formula (7) are shown below, but the present invention is not limited to these.

[0255] Chemical formula 45

[0256]

[0257] As the content of the above-mentioned basic compound in the hole transport layer, it is preferably 20 mol% to 65 mol% relative to the hole transport material, and more preferably 35 mol% to 50 mol%. When the content of the basic compound is within the preferred range, a high open circuit voltage can be maintained, a high output can be obtained, and even if it is used for a long time under various environments, high stability and durability can be obtained.

[0258] The molar ratio A / B of the basic compound A to the lithium salt B is preferably less than 2.0, more preferably 1.8 or less, and even more preferably 1.7 or less.

[0259] When the molar ratio A / B is less than 2.0, a high output when irradiated with low-illuminance light can be maintained for a long time, thereby having an advantage of being able to improve durability.

[0260] The hole transport layer may be a single-layer structure composed of a single material or a stacked structure including multiple compounds. When the hole transport layer is a stacked structure, a polymer material is preferably used in the hole transport layer close to the second electrode. When a polymer material with excellent film-forming properties is used, it is advantageous to be able to smooth the surface of the porous electron transport layer and to improve the photoelectric conversion characteristics. In addition, since it is difficult for the polymer material to penetrate into the porous electron transport layer, the porous electron transport layer has excellent coverage on the surface, and sometimes the effect of preventing short circuits when the electrodes are set can be obtained.

[0261] Examples of the polymer material used for the hole transport layer include known hole transport polymer materials.

[0262] Examples of the hole transporting polymer material include polythiophene compounds, polyphenylenevinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiadiazole compounds.

[0263] Examples of the polythiophene compound include poly(3-n-hexylthiophene), poly(3-n-octyloxythiophene), 9,9′-dioctylfluorene / bithiophene copolymer, poly(3,3″′-didodecyl-quaternary thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene), poly(2,5-bis(3-decylthien-2-yl)thieno[3,2-b]thiophene), 3,4-didecylthieno[3,2-b]thiophene copolymer, 3,6-dioctylthieno[3,2-b]thiophene / thieno[3,2-b]thiophene copolymer, 3,6-dioctylthieno[3,2-b]thiophene / thieno[3,2-b]thiophene copolymer, and 3,6-dioctylthieno[3,2-b]thiophene / bithiophene copolymer.

[0264] 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], and poly[(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene)-co-(4,4′-diphenylene-vinylene)] and the like.

[0265] Examples of the polyfluorene include poly(9,9′-didodecylfluorenyl-2,7-diyl), (9,9-dioctyl-2,7-divinylenefluorene) / (9,10-anthracene) alternating copolymers, (9,9-dioctyl-2,7-divinylenefluorene) / (4,4′-diphenylene) alternating copolymers, poly[(9,9-dioctyl-2,7-divinylenefluorene) / co-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene) alternating copolymers, and poly[(9,9-dioctyl-2,7-diyl) / (1,4-(2,5-dihexyloxy)benzene) alternating copolymers.

[0266] Examples of the polyphenylene compound include poly[2,5-dioctyloxy-1,4-phenylene] and poly[2,5-di(2-ethylhexyloxy-1,4-phenylene]].

[0267] Examples of the polyarylamine compound include 9,9-dioctylfluorenyl-2,7-diyl) / (N,N′-diphenyl)-N,N′-di(p-hexylphenyl)-1,4-diaminobenzene alternating copolymers, (9,9-dioctylfluorenyl-2,7-diyl) / (N,N′-bis(4-octyloxyphenyl)benzidine-N,N′-(1,4-diphenylene) alternating copolymers, 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[phenyleneimino-1,4-phenylenevinylene-2,5-dioctyloxy-1,4-phenylenevinylene-1,4-phenylene], poly[p-tolueneimino-1,4-phenylenevinylene-2,5-di(2-ethylhexyloxy)-1,4-phenylenevinylene-1,4-phenylene], poly[4-(2-ethylhexyloxy)phenyleneimino-1,4-diphenylene], and the like.

[0268] Examples of the polythiadiazole compound include (9,9-dioctylfluorenyl-2,7-diyl) / (1,4-benzo(2,1′,3)thiadiazole alternating copolymers and 3,4-didecylthiophene / (1,4-benzo(2,1′,3)thiadiazole copolymers.

[0269] Among them, polythiophene compounds and polyarylamine compounds are preferred from the viewpoint of carrier mobility and ionization potential.

[0270] The average thickness of the hole transport layer is not particularly limited and can be appropriately selected according to the purpose, but preferably has a structure that enters the pores of the porous electron transport layer. On the electron transport layer, it is more preferably 0.01 μm to 20 μm, further preferably 0.1 μm to 10 μm, and particularly preferably 0.2 μm to 2 μm.

[0271] The hole transport layer can be directly formed on the electron transport layer adsorbed with the photosensitizing compound. There is no particular limitation on the method for making the hole transport layer, and it can be appropriately selected according to the purpose, and methods such as vacuum evaporation and the like to form a thin film in a vacuum, wet film forming methods, etc. can be cited. Among them, from the perspective of manufacturing cost, the wet film forming method is particularly preferred, and the method of coating on the electron transport layer is preferred.

[0272] When a wet film-forming method is used, there is no particular limitation on the coating method, and the coating method may be carried out according to a known method, such as dip coating, spray coating, wire rod coating, spin coating, roller coating, blade coating, and gravure coating. In addition, various wet printing methods such as letterpress, offset printing, gravure, intaglio, rubber printing, and screen printing may be used.

[0273] In addition, film making can also be carried out in a supercritical fluid or a subcritical fluid at a temperature and pressure lower than the critical point. A supercritical fluid exists as a non-cohesive high-density fluid in a temperature and pressure region exceeding the limit (critical point) at which gas and liquid can coexist, and does not condense even when compressed. As long as the fluid is in a state above the critical temperature and above the critical pressure, there is no particular restriction, and it can be appropriately selected according to the purpose, but preferably the fluid with a low critical temperature.

[0274] Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, and ether solvents.

[0275] Examples of the alcohol solvent include methanol, ethanol, and n-butanol.

[0276] Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene, etc. Examples of the halogen solvent include dichloromethane, chlorotrifluoromethane, etc.

[0277] Examples of the ether solvent include dimethyl ether and the like.

[0278] These may be used alone or in combination of two or more.

[0279] Among them, carbon dioxide is preferred because it has a critical pressure of 7.3 MPa and a critical temperature of 31° C., can easily produce a supercritical state, and is non-flammable and easy to handle.

[0280] The subcritical fluid is not particularly limited as long as it exists as a high-pressure liquid in a temperature and pressure region near the critical point, and can be appropriately selected depending on the purpose. The compounds listed as supercritical fluids can also be preferably used as subcritical fluids.

[0281] The critical temperature and critical pressure of the supercritical fluid are not particularly limited and may be appropriately selected depending on the intended purpose. The critical temperature is preferably -273°C to 300°C, more preferably 0°C to 200°C.

[0282] Furthermore, in addition to the supercritical fluid and the subcritical fluid, an organic solvent or an entrainer may be used in combination. By adding an organic solvent or an entrainer, the solubility in the supercritical fluid can be more easily adjusted.

[0283] The organic solvent is not particularly limited and may be appropriately selected depending on the purpose. Examples of the organic solvent include ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents.

[0284] Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0285] Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate.

[0286] Examples of the ether solvent include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane.

[0287] Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0288] Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, iodomethane, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0289] Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene.

[0290] These may be used alone or in combination of two or more.

[0291] Alternatively, a pressing step may be performed after stacking a hole transport material on the electron transport layer on which the photosensitizing compound is adsorbed. Pressing may allow the hole transport material to be more closely attached to the electron transport layer as a porous electrode, thereby improving efficiency.

[0292] The method for the compression treatment is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include a compression molding method using a flat plate represented by an IR tablet molding machine, and a roll pressing method using a roll or the like.

[0293] The pressure is preferably 10 kgf / cm 2 More preferably, 30 kgf / cm 2 above.

[0294] The time of the pressing treatment is not particularly limited and can be appropriately selected according to the purpose, but is preferably less than 1 hour. In addition, heating can also be performed during the pressing treatment. During the pressing treatment, a release agent can be sandwiched between the pressing machine and the electrode.

[0295] As the release agent, for example, there can be mentioned fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, perfluoroalkoxy fluorinated resin, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polyvinyl fluoride, etc. These may be used alone or in combination of two or more.

[0296] After the pressing step and before the second electrode is provided, a metal oxide may be provided between the hole transport material and the second electrode.

[0297] 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 them, molybdenum oxide is preferred.

[0298] The method for providing the metal oxide on the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include a method of forming a thin film in a vacuum such as sputtering or vacuum deposition, and a wet film forming method.

[0299] As a wet film-forming method, it is preferred to prepare a paste of a powder or sol dispersed with a metal oxide and apply it on the hole transport layer. When using a wet film-forming method, there is no particular limitation as a coating method, and it can be carried out according to a known method, for example, dip coating, spray coating, wire rod coating, spin coating, roller coating, blade coating, gravure coating, and as a wet printing method, various methods such as movable type, offset plate, gravure, intaglio, rubber plate, and screen printing can be used.

[0300] The average thickness of the applied metal oxide is preferably from 0.1 nm to 50 nm, and more preferably from 1 nm to 10 nm.

[0301] <<Hole blocking layer>>

[0302] In the present invention, a hole blocking layer can be formed, which is very effective for increasing the output and improving its sustainability. The hole blocking layer is formed between the first electrode and the electron transport layer. The hole blocking layer can transfer electrons generated by the photosensitizing compound and transferred to the electron transport layer to the first electrode, and prevent contact with the hole transport layer. Thus, the hole blocking layer makes it difficult for holes to flow into the first electrode, and can suppress the reduction in output caused by the recombination of electrons and holes. Compared with the wet type using an electrolyte, the solid-type photoelectric conversion element provided with a hole transport layer has a fast recombination rate between holes in the hole transport material and electrons on the electrode surface, so the effect brought about by the formation of the hole blocking layer is very large.

[0303] 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, element semiconductors such as silicon and germanium, compound semiconductors represented by metal chalcogenides, compounds with a perovskite structure, etc. can be listed.

[0304] Examples of metal chalcogenides include oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium, lead, and the like; and tellurides of cadmium. Examples of other compound semiconductors include phosphides of zinc, gallium, indium, cadmium, and the like, gallium arsenide, copper-indium-selenide, and copper-indium-sulfide.

[0305] Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate.

[0306] Among them, oxide semiconductors are preferred, titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide, tin oxide and the like are more preferred, and titanium oxide is further preferred.

[0307] These can be used alone or in combination of two or more. In addition, they can be either monolayer or laminated. In addition, the crystal form of these semiconductors is not particularly limited and can be appropriately selected according to the purpose, and can be single crystal, polycrystalline or amorphous.

[0308] The method for producing the hole blocking layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of forming a thin film in a vacuum (vacuum film forming method) and a wet film forming method.

[0309] Examples of vacuum film forming methods include sputtering, pulsed laser deposition (PLD), ion beam sputtering, ion-assisted deposition, ion plating, vacuum evaporation, atomic layer deposition (ALD), and chemical vapor deposition (CVD).

[0310] As a wet film-forming method, for example, a sol-gel method can be cited. The sol-gel method is a method of preparing a gel from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then promoting densification by heat treatment. When using the sol-gel method, there is no particular limitation on the coating method of the sol solution, and it can be carried out according to a known method. For example, dip coating, spray coating, wire rod coating, spin coating, roller coating, blade coating, gravure coating, and wet printing methods can be used. In addition, a movable type, offset plate, gravure, intaglio, rubber plate, screen printing, etc. can be used. In addition, the temperature during the heat treatment after applying the sol solution is preferably above 80°C, and more preferably above 100°C.

[0311] The average thickness of the hole blocking layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 nm to 1 μm, more preferably 500 nm to 700 nm in wet film formation, and more preferably 5 nm to 30 nm in dry film formation.

[0312] <<Second Electrode>>

[0313] The second electrode may be formed on the hole transport layer or on the metal oxide in the hole transport layer. In addition, the second electrode may be the same electrode as the first electrode, and the second substrate is not necessarily required if sufficient strength is maintained.

[0314] Examples of the material of the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers.

[0315] Examples of the metal include platinum, gold, silver, copper, and aluminum.

[0316] Examples of the carbon compound include graphite, fullerene, carbon nanotube, and graphene.

[0317] Examples of the conductive metal oxide include ITO, FTO, and ATO.

[0318] Examples of the conductive polymer include polythiophene and polyaniline.

[0319] These may be used alone or in combination of two or more.

[0320] The second electrode can be formed on the hole transport layer by an appropriate coating method, lamination method, vapor deposition method, CVD method, lamination method or the like, depending on the type of material used and the type of the hole transport layer.

[0321] In the photoelectric conversion element, at least one of the first electrode and the second electrode is preferably substantially transparent. It is preferred that the first electrode side is transparent so that incident light enters from the first electrode side. In this case, it is preferred to use a material that reflects light on the second electrode side, preferably a metal, glass with a conductive oxide vapor-deposited thereon, plastic, or a metal film. In addition, it is also an effective method to provide a reflection prevention layer on the incident light side.

[0322] <<Second substrate>>

[0323] The second substrate is not particularly limited, and a known substrate can be used, for example, glass, plastic film, ceramic, etc. In order to improve the adhesion of the joint between the second substrate and the sealing member, a concavo-convex portion may be formed.

[0324] The method for forming the concavoconvex portion is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include sandblasting, water blasting, abrasive paper, chemical etching, and laser processing.

[0325] As the method for improving the adhesion of the second substrate and the sealing component, for example, the organic matter on the surface can be removed, and the hydrophilicity can also be improved. As the method for removing the organic matter on the second substrate surface, there is no particular restriction, and it can be appropriately selected according to the purpose, for example, UV ozone cleaning, oxygen plasma treatment, etc. can be listed.

[0326] <<Sealing Parts>>

[0327] The photoelectric conversion element of the present invention can effectively use a sealing member that can shield at least the electron transport layer and the hole transport layer from the external environment of the photoelectric conversion element.

[0328] As the sealing member, any method known in the past can be used as long as it can reduce the intrusion of excess moisture or oxygen from the external environment into the sealed interior. In addition, the sealing member also has the effect of preventing mechanical damage caused by external pressure, and any method known in the past can be used as long as this effect can be achieved.

[0329] The sealing method can be roughly divided into "frame sealing" in which a sealing component is provided at the periphery of the power generation area constituted by the photoelectric conversion layer of the photoelectric conversion element and bonded to the second substrate, and "surface sealing" in which a sealing component is provided on the entire surface of the power generation area and bonded to the second substrate. The former "frame sealing" can form a hollow part inside the seal, so the amount of moisture and oxygen inside the seal can be appropriately adjusted. In addition, since the second electrode does not contact the sealing component, it has the effect of reducing the influence of electrode peeling. On the other hand, the latter "surface sealing" has an excellent effect of preventing the intrusion of excess water or oxygen from the outside. In addition, since the bonding area with the sealing component is large, the sealing strength is high, which is particularly suitable for the case where a flexible substrate is used in the first substrate.

[0330] There is no particular restriction on the type of the sealing member, and it can be appropriately selected according to the purpose, for example, curing resin or low melting point glass resin can be listed. As the curing resin, there is no particular restriction as long as it is a resin that is cured by light or heat, and it can be appropriately selected according to the purpose, and acrylic resin or epoxy resin is preferably used.

[0331] As the cured product of acrylic resin, any known material may be used as long as it is obtained by curing a monomer or oligomer having an acrylic group in the molecule.

[0332] As the cured product of epoxy resin, any known material may be used as long as it is obtained by curing a monomer or oligomer having an epoxy group in the molecule.

[0333] As epoxy resin, for example, water dispersion system, solvent-free system, solid system, heat curing type, curing agent mixed type, ultraviolet curing type etc. can be listed. Among them, heat curing type and ultraviolet curing type are preferred, and ultraviolet curing type is more preferred. In addition, even if it is ultraviolet curing type, it can be heated, and it is preferred to heat even after ultraviolet curing.

[0334] Examples of epoxy resins include bisphenol A type, bisphenol F type, novolac type, cyclic aliphatic 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.

[0335] It is preferred that the epoxy resin be mixed with a curing agent and various additives as necessary.

[0336] The curing agent is classified into amine-based, acid anhydride-based, polyamide-based or other curing agents, and is appropriately selected according to the purpose.

[0337] Examples of the amine curing agent include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.

[0338] Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, cyclohexaneic anhydride, and dodecenylsuccinic anhydride.

[0339] As other curing agents, for example, imidazoles, polythiol, etc. can be mentioned. These may be used alone or in combination of two or more.

[0340] As additives, for example, there can be listed fillers (fillers), interstitials, polymerization initiators, desiccants (moisture absorbents), curing accelerators, coupling agents, flexibilizers, colorants, flame retardant aids, antioxidants, organic solvents, etc. Among them, fillers, interstitials, curing accelerators, polymerization initiators, desiccants (moisture absorbents) are preferred, and fillers and polymerization initiators are more preferred.

[0341] In addition to being effective in suppressing the infiltration of moisture or oxygen, the filler can also reduce the volume shrinkage during curing, reduce the amount of degassing during curing or heating, improve mechanical strength, control thermal conductivity and fluidity, and is very effective in maintaining stable output under 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 the influence of degassing generated when the sealing component is cured or heated. In particular, the influence of degassing generated during heating has a great impact on the output characteristics during storage in a high-temperature environment.

[0342] At this time, by making the sealing component contain fillers, gap agents, and desiccants, in addition to being able to inhibit the infiltration of moisture and oxygen, the amount of sealing component used can be reduced, thereby achieving the effect of reducing degassing. This is effective not only during curing, but also when the photoelectric conversion element is stored in a high temperature environment.

[0343] As a filler, there is no particular limitation, and known materials can be used, for example, preferably crystalline or amorphous silica, talc, aluminum oxide, aluminum nitride, silicon nitride, calcium silicate, calcium carbonate and other inorganic fillers. 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 to 10 μm, more preferably 1 μm to 5 μm. When the addition amount is within the preferred range, the effect of suppressing the intrusion of moisture and oxygen can be fully obtained, and the viscosity becomes appropriate, which is also effective for improving the adhesion and degassing properties with the substrate, or controlling the width of the sealing portion and operability.

[0344] The content of the filler is preferably 10 to 90 parts by mass, and more preferably 20 to 70 parts by mass, relative to 100 parts by mass of the entire sealing component. By making the content of the filler within the above range, the effect of suppressing the intrusion of moisture and oxygen can be fully obtained, the viscosity becomes appropriate, and the adhesion and operability also become good.

[0345] The gap agent is also called a gap control agent or a spacer, and can control the gap of the sealing part. For example, when a sealing part is provided on the first substrate or the first electrode and a second substrate is placed thereon for sealing, by mixing the gap agent in the epoxy resin, the gap of the sealing part is aligned with the size of the gap agent, so that the gap of the sealing part can be easily controlled.

[0346] As the interstitial agent, any known material can be used as long as it is granular, has uniform particle size, and has high solvent resistance and heat resistance. It is preferred that the interstitial agent has high affinity with epoxy resin and is spherical in shape. Specifically, glass beads, silica particles, organic resin particles, etc. can be exemplified. These can be used alone or in combination of two or more.

[0347] The average particle size of the gap agent can be selected according to the gap of the sealing portion to be set, but is preferably 1 μm to 100 μm, and more preferably 5 μm to 50 μm.

[0348] The polymerization initiator is a material added for the purpose of starting polymerization using heat or light.

[0349] Thermal polymerization initiators are compounds that generate active species such as free radicals or cations by heating. Specifically, azo compounds such as 2,2'-azobisisobutyronitrile (AIBN), peroxides such as benzoyl peroxide (BPO), etc. can be used. As thermal cationic polymerization initiators, benzenesulfonates, alkyl sulfonium salts, etc. can be used. On the other hand, when the photopolymerization initiator is an epoxy resin, it is preferred to use a photocationic polymerization initiator. When the photocationic polymerization initiator is mixed with the epoxy resin and irradiated with light, the photocationic polymerization initiator decomposes to generate a strong acid, which causes the polymerization of the epoxy resin and the curing reaction proceeds. The photocationic polymerization initiator has the effects of less volume shrinkage during curing, is not inhibited by oxygen, and has high storage stability.

[0350] Examples of the photocationic polymerization initiator include methyl salts, aromatic iodonium salts, aromatic sulfonium salts, metallocene compounds, and silanol·aluminum complexes.

[0351] In addition, a photoacid generator having a function of generating an acid by irradiation with light may also be used. The photoacid generator acts as an acid to start cationic polymerization, and for example, onium salts such as ionic sulfonium salts or iodonium salts composed of a cation part and an anion part may be cited. These may be used alone or in combination of two or more.

[0352] The amount of the polymerization initiator added may vary depending on the material used, but is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the entire sealing component. When the amount added is within the above range, curing is properly performed, the remaining uncured material can be reduced, and excess degassing can be prevented, which is effective.

[0353] A desiccant, also called a moisture absorber, is a material having the function of physically or chemically adsorbing moisture and absorbing moisture. Including a desiccant in a sealing component is effective because it can sometimes further improve moisture resistance or reduce the influence of degassing.

[0354] As the desiccant, it is preferably in a particle form, and for example, inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolites can be cited. Among them, zeolites with a large moisture absorption capacity are preferred. These can be used alone or in combination of two or more.

[0355] Curing accelerators, also known as curing catalysts, are used to accelerate the curing speed and are mainly used for thermosetting epoxy resins.

[0356] Examples of the curing accelerator include tertiary amines or tertiary amine salts such as DBU (1,8-diazabicyclo (5,4,0)-undecene-7) and DBN (1,5-diazabicyclo (4,3,0)-nonene-5), imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, and phosphines or phosphonium salts such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate. These may be used alone or in combination of two or more.

[0357] The coupling agent has an effect of improving molecular bonding strength, and a silane coupling agent can be cited, for example, 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, etc. These can be used alone or in combination of two or more.

[0358] Further, the sealing component is known to have commercially available epoxy resin compositions as sealing materials, leakproof materials or adhesives, and can also be effectively used in the present invention. Wherein, there are also commercially available epoxy resin compositions developed for solar cells or organic EL element uses, which can especially be effectively used in the present invention. For example, TB3118, TB3114, TB3124, TB3125F (manufactured by Threebond), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyoritsu Chemical), WB90US (P) (manufactured by MORESCO), etc. can be cited.

[0359] On the other hand, after the low-melting-point glass resin is coated with the resin, the resin component is decomposed by a firing process at about 550°C, and then melted by infrared laser or the like and tightly bonded to the glass substrate. At this time, the low-melting-point glass component diffuses into the interior of the metal oxide layer, and a high sealing performance can be obtained by physical bonding. In addition, due to the disappearance of the resin component, degassing does not occur like acrylic resin or epoxy resin, so the photoelectric conversion element will not deteriorate, which is effective.

[0360] In the present invention, in addition to this, a sheet-like sealing material can also be used. The sheet-like sealing material is a sheet material on which an epoxy resin layer is pre-formed. The sheet material is used for glass or a film with high gas barrier properties, etc., which is equivalent to the second substrate in the present invention. By attaching the sheet-like sealing material to the second electrode and then curing it, the sealing component and the second substrate can be formed at one time. By forming a pattern of the epoxy resin layer formed on the sheet material, a structure with a hollow portion can also be formed, which is effective. If the resin layer formed on the sheet material is formed on the entire surface, it becomes a "surface seal", but if the resin layer is patterned by forming a pattern of the resin layer so that a hollow portion is provided inside the photoelectric conversion element, it becomes a "frame seal".

[0361] There is no particular limitation on the method for forming the sealing component, and the sealing component can be formed by a known method, for example, a dispenser method, a wire rod method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method, a movable type, an offset plate, an intaglio, a rubber plate, a screen printing method or the like.

[0362] Furthermore, a passivation layer may be provided between the sealing member and the second electrode. The passivation layer is not particularly limited as long as it is arranged so as not to contact the second electrode, and may be appropriately selected according to the purpose, and preferably aluminum oxide, silicon nitride, silicon oxide, or the like is used.

[0363] Hereinafter, the mode for carrying out the invention will be described with reference to the accompanying drawings. In each of the drawings, the same reference numerals are given to the same components, and their repeated descriptions may be omitted.

[0364] By making the hollow part inside the seal contain oxygen, the hole transport function of the hole transport part can be maintained stably for a long time, which is effective for improving the durability of the photoelectric conversion element. In the present invention, the oxygen concentration of the hollow part inside the seal set by sealing can obtain the effect as long as it contains oxygen, but it is more preferably 5.0 volume % or more and 21.0 volume % or less.

[0365] The oxygen concentration of the hollow portion can be controlled by sealing in a glove box with an adjusted oxygen concentration. The oxygen concentration can be adjusted by using a gas cylinder with a specific oxygen concentration or a nitrogen generator. The oxygen concentration in the glove box is measured using a commercially available oxygen concentration meter or oxygen monitor.

[0366] The oxygen concentration in the hollow portion formed by sealing can be measured, for example, by atmospheric pressure ionization mass spectrometry (API-MS). Specifically, the photoelectric conversion element is placed in a chamber filled with an inert gas, the seal is opened in the chamber, and the gas in the chamber is quantitatively analyzed by API-MS to quantify all components in the gas contained in the hollow portion, and the oxygen concentration can be obtained by calculating the ratio of oxygen to the total.

[0367] As the gas other than oxygen, an inert gas is preferable, and examples thereof include nitrogen and argon.

[0368] When sealing, it is preferred to control the dew point in the glove box together with the oxygen concentration, which is effective for improving output and durability. The dew point is defined as the temperature at which water vapor begins to condense when the gas containing water vapor is cooled.

[0369] The dew point is not particularly limited, but is preferably 0° C. or lower, more preferably -20° C. or lower. The lower limit is preferably -50° C. or higher.

[0370] Hereinafter, the photoelectric conversion element of the present invention will be described with reference to the drawings. However, the present invention is not limited thereto, and for example, the number, position, shape, etc. of the following components that are not described in this embodiment are also included in the scope of the present invention.

[0371] <First embodiment>

[0372] Figure 1 FIG. 1 is a schematic diagram of a photoelectric conversion element according to the first embodiment. Figure 1 The photoelectric conversion element 101 of the first embodiment has a first electrode 2 formed on a first substrate 1. An electron transport layer 4 is formed on the first electrode 2, and a photosensitizing compound 5 is adsorbed on the surface of an electron transport material constituting the electron transport layer 4. A hole transport layer 6 is formed on and inside the electron transport layer 4, and a second electrode 7 is formed on the hole transport layer 6. A second substrate 9 is arranged above the second electrode 7, and the second substrate 9 and the first electrode 2 are fixed by a sealing member 8.

[0373] Should Figure 1 The photoelectric conversion element 101 of the first embodiment has a hollow portion 10 between the second electrode 7 and the second substrate 9. By having the hollow portion 10, the amount of water and the oxygen concentration in the hollow portion can be controlled, which has the advantage of being able to improve the power generation performance and its durability. Furthermore, since the second electrode 7 is not in contact with the second substrate 9, the peeling and damage of the second electrode 7 can be prevented. The oxygen concentration in the hollow portion is not particularly limited and can be freely selected, but is preferably 0% to 21%, and more preferably 5% to 15%.

[0374] Although not shown in the figure, the first electrode 2 and the second electrode 7 each have a path that is electrically connected to the electrode extraction terminal.

[0375] <Second embodiment>

[0376] Figure 2 FIG. 2 is a schematic diagram of a photoelectric conversion element according to the second embodiment. Figure 2 The photoelectric conversion element 101 of the second embodiment has a hole blocking layer 3 formed between the first substrate 1 and the electron transport layer 4. The hole blocking layer 3 can prevent the recombination of electrons and holes, which is effective in improving the power generation performance. Figure 2 The photoelectric conversion element shown is Figure 1 Similarly, a hollow portion 10 is provided between the second electrode 7 and the second substrate 9 .

[0377] <Third embodiment>

[0378] Figure 3 FIG. 2 is a schematic diagram of a photoelectric conversion element according to the third embodiment. Figure 3 The photoelectric conversion element 101 of the third embodiment does not have a hollow portion of a sealing portion, but is covered with a sealing member 8. Figure 2 The hollow portion 10 shown in the figure can be formed by, for example, applying a sealing member 8 to the entire surface of the second electrode 7 and placing a second substrate 9 thereon, or by using the above-mentioned sheet-like sealing material. In this case, the hollow portion inside the seal can be completely eliminated, or a part of the hollow portion can be retained. In this way, by covering substantially the entire surface with a sealing member, the peeling or damage of the second substrate 9 can be reduced, and the mechanical strength of the photoelectric conversion element can be improved.

[0379] <Fourth embodiment>

[0380] Figure 4 FIG. 2 is a schematic diagram of a photoelectric conversion element according to the fourth embodiment. Figure 4 The sealing member 8 of the photoelectric conversion element 101 of the fourth embodiment is bonded to the first substrate 1 and the second substrate 9. By forming such a structure, the adhesion between the sealing member 8 and the substrate is improved, and the mechanical strength of the photoelectric conversion element can be improved. In addition, by improving the adhesion, the sealing effect of preventing the intrusion of moisture or oxygen can be further improved.

[0381] (Photoelectric conversion module)

[0382] In the photoelectric conversion module of the present invention, the photoelectric conversion elements are electrically connected in series or in parallel.

[0383] The photoelectric conversion module of the present invention has, for example, a photoelectric conversion element arrangement region where a plurality of photoelectric conversion elements are adjacently arranged and connected in series or in parallel, and the plurality of photoelectric conversion elements have a photoelectric conversion layer including an electron transport layer and a hole transport layer formed between a first electrode and a second electrode.

[0384] The photoelectric conversion module of the present invention may be configured to include a plurality of the above-mentioned photoelectric conversion elements. In addition, the above-mentioned plurality of photoelectric conversion elements may be connected in series and / or in parallel, or may include independent photoelectric conversion elements that are not connected.

[0385] The configuration of each layer of the photoelectric conversion module may be the same as that of the above-mentioned photoelectric conversion element.

[0386] The structure of the photoelectric conversion module is not particularly limited and can be appropriately selected according to the purpose, but the first electrode, the electron transport layer, and the second electrode are preferably divided in at least two mutually adjacent photoelectric conversion elements, thereby reducing the risk of short circuit. On the other hand, the hole transport layer can be divided in at least two mutually adjacent photoelectric conversion elements, or it can be a continuous layer in which the hole transport layer is extended to each other.

[0387] In addition, in the photoelectric conversion module, among at least two adjacent photoelectric conversion elements, the first electrode in one photoelectric conversion element and the second electrode in another photoelectric conversion element are preferably electrically connected via a conductive portion that penetrates at least the hole transport layer to the hole blocking layer.

[0388] The photoelectric conversion module includes a pair of substrates and a region where photoelectric conversion elements connected in series or in parallel are arranged between the pair of substrates. The sealing member may be sandwiched between the pair of substrates.

[0389] The photoelectric conversion module of the present invention can be applied to a power supply device by combining a circuit board or the like that controls the generated current. As devices using the power supply device, for example, electronic desktop computers and watches can be cited. In addition, the power supply device having the photoelectric conversion module of the present invention can also be applied to mobile phones, electronic notebooks, electronic paper, etc. In addition, as an auxiliary power source for extending the continuous use time of rechargeable or dry battery-type electrical appliances, the power supply device having the photoelectric conversion module of the present invention can also be used as a power source that can be used at night, etc. by combining with a secondary battery, etc. Furthermore, as an independent power source that does not require battery replacement, power wiring, etc., it can also be used in IoT devices, artificial satellites, etc.

[0390] (Electronic Instruments)

[0391] The electronic device of the present invention comprises the photoelectric conversion module of the present invention, and a device operated by electric power generated by photoelectric conversion performed by the photoelectric conversion module, and further comprises other devices as necessary.

[0392] (Power Module)

[0393] The power module of the present invention includes the photoelectric conversion module of the present invention and a power circuit (IC: Integrated Circuit), and may further include other devices as required.

[0394] Next, specific embodiments of the photoelectric conversion module of the present invention and an electronic device having a device operated by the electric power generated by the photoelectric conversion module will be described.

[0395] Figure 5 This is a block diagram of a personal computer mouse as an example of the electronic device of the present invention.

[0396] like Figure 5 As shown, the photoelectric conversion module, the power IC, and the power storage device are combined, and the supplied power is connected to the power supply of the mouse control circuit. In this way, the power storage device can be charged when the mouse is not in use, and the mouse can be operated using the power, so that a mouse that does not require wiring or battery replacement can be obtained. In addition, since no battery is required, it can also be lightweight, which is effective.

[0397] Figure 6 yes Figure 5 A schematic external view of an example of a mouse is shown.

[0398] like Figure 6 As shown, the photoelectric conversion module, power IC, and power storage device are assembled inside the mouse, but the upper part of the photoelectric conversion element is covered by a transparent frame so that light can be irradiated to the photoelectric conversion element of the photoelectric conversion module. In addition, the entire shell of the mouse can also be molded with a transparent resin. The configuration of the photoelectric conversion element is not limited to this, for example, it can also be configured in a position where light can be irradiated even if the mouse is covered by hand, which is sometimes preferred.

[0399] Next, other embodiments of the photoelectric conversion module of the present invention and electronic equipment having a device operated by the electric power generated by the photoelectric conversion module will be described.

[0400] Figure 7 This is a block diagram of a personal computer keyboard as an example of the electronic device of the present invention.

[0401] like Figure 7As shown, the photoelectric conversion element of the photoelectric conversion module is combined with the power IC and the power storage device, and the supplied power is connected to the power supply of the keyboard control circuit. In this way, the power storage device can be charged when the keyboard is not in use, and the keyboard can be operated using the power, so that a keyboard that does not require wiring or battery replacement can be obtained. In addition, since no battery is required, it can also be lightweight, which is effective.

[0402] Figure 8 yes Figure 7 A schematic external view of an example of a keyboard is shown.

[0403] like Figure 8 As shown in FIG. 1 , the photoelectric conversion element, power IC, and power storage device of the photoelectric conversion module are assembled inside the keyboard, but the upper part of the photoelectric conversion element is covered by a transparent frame to allow light to irradiate the photoelectric conversion element. In addition, the entire keyboard shell can also be molded with a transparent resin. The configuration of the photoelectric conversion element is not limited to this. In the case of a small keyboard with a small space for assembling the photoelectric conversion element, such as Fig. 9 As shown, a small photoelectric conversion element can also be embedded in a part of the key, which is effective.

[0404] Next, other embodiments of the photoelectric conversion module of the present invention and electronic equipment having a device operated by the electric power generated by the photoelectric conversion module will be described.

[0405] Fig.10 This is a block diagram of a sensor as an example of the electronic device of the present invention.

[0406] like Fig.10 As shown, the photoelectric conversion element of the photoelectric conversion module is combined with the power supply IC and the power storage device, and the supplied power is connected to the power supply of the sensor circuit. In this way, the sensor module can be constructed without connecting to an external power supply or replacing the battery. As the sensing object, it can be applied to various sensors such as temperature and humidity, illumination, human sensation, CO2, acceleration, UV, noise, geomagnetism, and air pressure, which is effective. Fig.11 As shown, the sensor module is configured to periodically sense the measurement object and send the read data to a PC or smartphone via wireless communication.

[0407] With the advent of the Internet of Things (IoT) society, sensors are expected to increase dramatically. It takes a lot of time to replace the batteries of the countless sensors one by one, which is unrealistic. In addition, the location of the sensors in places such as ceilings or walls where it is difficult to replace the batteries also deteriorates the operability. The advantage of being able to supply power through photoelectric conversion elements is also very great. In addition, the photoelectric conversion module of the present invention can obtain high output even under low illumination, and the output light has a small dependence on the incident angle, so it can also obtain the advantage of high setting freedom.

[0408] Next, other embodiments of the photoelectric conversion module of the present invention and electronic equipment having a device operated by the electric power generated by the photoelectric conversion module will be described.

[0409] Fig.11 This is a block diagram of a turntable as an example of the electronic device of the present invention.

[0410] like Fig.11 As shown, the photoelectric conversion element is combined with the power IC and the power storage device, and the supplied power is connected to the power supply of the turntable circuit. In this way, the turntable can be constructed without connecting to an external power supply or replacing the battery. The turntable is used, for example, as a display cabinet for displaying goods. Since the wiring appearance of the power supply is poor and the displayed items must be removed when replacing the battery, it takes a lot of time and labor. By using the photoelectric conversion module of the present invention, such undesirable situations can be eliminated, which is effective.

[0411] The photoelectric conversion module of the present invention, the electronic device having a device operated by the electric power generated by the photoelectric conversion module, and the power supply module have been described above. However, these are only a part of the description, and the photoelectric conversion module of the present invention is not limited to these uses.

[0412] <Application>

[0413] The photoelectric conversion module of the present invention can function as an independent power source, and can use the power generated by photoelectric conversion to operate the device. The photoelectric conversion module of the present invention can generate electricity by irradiation with light, so there is no need to connect the electronic device to the power source or replace the battery. Therefore, the electronic device can be operated even in a place without a power supply device, or can be carried with you, or can be operated without replacing the battery even in a place where battery replacement is difficult. In addition, when using dry batteries, the electronic device becomes heavier and larger in size, which sometimes brings obstacles to the installation and transportation to the wall or ceiling, but the photoelectric conversion module of the present invention is light and thin, so it has a high degree of freedom in installation, and it is also great in terms of being worn on the body and carrying.

[0414] Thus, the photoelectric conversion module of the present invention can be used as an independent power source and can be combined with various electronic instruments. For example, it can be combined with electronic desktop computers, watches, mobile phones, electronic notebooks, electronic paper and other display devices, personal computer accessories such as mice or keyboards, various sensor devices such as temperature and humidity sensors or human sensors, beacons or GPS transmitters, auxiliary lights, remote controllers and other electronic instruments for use.

[0415] The photoelectric conversion module of the present invention can generate electricity especially under low illumination, so it can also generate electricity indoors and even in dim shadows, so it has a wide range of applications. In addition, it will not leak like dry batteries, nor will it be accidentally drunk like button batteries, and is highly safe. Furthermore, it can be used as an auxiliary power source for extending the continuous use time of rechargeable or dry battery-type electrical appliances. In this way, by combining the photoelectric conversion module of the present invention and a device that operates using the electricity generated by its photoelectric conversion, it can become an electronic instrument that is lightweight and easy to use, has a high degree of freedom in setting, does not require replacement, has excellent safety, and is effective in reducing environmental load.

[0416] Fig.12 The figure shows the basic structure of an electronic device that combines the photoelectric conversion module of the present invention with a device that operates by the power generated by the photoelectric conversion. When light is irradiated to the photoelectric conversion element, electricity is generated and electricity can be extracted. The circuit of the device can be operated by the electricity.

[0417] However, since the output of the photoelectric conversion element of the photoelectric conversion module changes according to the surrounding illumination, Fig.12 Sometimes the electronic equipment shown does not work stably. Fig.13 As shown, in order to supply a stable voltage to the circuit side, a power supply IC for the photoelectric conversion element can be installed between the photoelectric conversion element and the circuit of the device, which is effective.

[0418] However, although the photoelectric conversion element of the photoelectric conversion module can generate electricity as long as it is irradiated with light of sufficient illumination, if the illumination used for power generation is insufficient, the desired power cannot be obtained, which is also a disadvantage of the photoelectric conversion element. Fig.14 As shown, by installing a power storage device such as a capacitor between the power supply IC and the device circuit, the surplus power from the photoelectric conversion element can be charged to the power storage device. Even when the illumination is too low or light cannot reach the photoelectric conversion element, the power stored in the power storage device can be supplied to the device circuit, thereby enabling it to operate stably.

[0419] Thus, in an electronic instrument combining the photoelectric conversion module and device circuit of the present invention, the combination of the power supply IC and the power storage device can operate even in an environment without power supply. In addition, there is no need to replace the battery, and the electronic instrument can be driven stably, and the advantages of the photoelectric conversion element can be utilized to the maximum extent.

[0420] On the other hand, the photoelectric conversion module of the present invention can also be used as a power supply module and is useful. Fig.15 As shown, when the photoelectric conversion module of the present invention is connected to a power supply IC for a photoelectric conversion element, a DC power supply module can be formed, so that the power generated by photoelectric conversion of the photoelectric conversion element of the photoelectric conversion module can be supplied to the power supply IC at a certain voltage level.

[0421] Furthermore, if Fig.16 As shown, by adding a power storage device to the power IC, the power generated by the photoelectric conversion element of the photoelectric conversion module can be charged into the power storage device, and a power module that can supply power can be formed even when the illumination is too low or the photoelectric conversion element is not illuminated by light.

[0422] Fig.15 and Fig.16 The power module of the present invention shown in the figure does not require battery replacement like conventional primary batteries, and can be used as a power module.

[0423] [Example]

[0424] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0425] (Example 1) <Fabrication of Photoelectric Conversion Module>

[0426] On a glass substrate as the first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) were sputtered in sequence as the first electrode. Next, a dense layer (average thickness 20 nm) of titanium oxide was formed as a hole blocking layer by reactive sputtering using oxygen.

[0427] Next, titanium oxide (Greatcell Solar Materials, 18NR-T) paste was applied to the hole blocking layer by screen printing to an average thickness of about 1.3 μm. After drying at 120°C, it was fired at 550°C for 30 minutes in air to form a porous electron transport layer. Then, the ITO / NTO layer, the hole blocking layer, and the electron transport layer were divided into 8 units by laser processing.

[0428] The glass substrate formed with the electron transport layer was immersed in a solution prepared by adding a mixed solution of acetonitrile / tert-butanol (volume ratio 1:1) to the photosensitizing compound (0.2 mM) shown in the above B1-1 and stirring, and the solution was allowed to stand in a dark place for 1 hour to allow the photosensitizing compound to be adsorbed on the surface of the electron transport layer.

[0429] Next, 70.2 mM of lithium (fluorosulfonyl) (trifluoromethanesulfonyl) imide (Li-FTFSI) (manufactured by Kishida Chemical Co., Ltd.), 145.8 mM of the pyridine compound A shown in H-1, 162.0 mM of the organic hole transport material (HTM) (SHT-263, manufactured by Merck Co., Ltd.) shown in D-7, and 12.6 mM of the cobalt complex (manufactured by Greatcell Solar Materials Co., Ltd.) shown in F-11 were added and dissolved in the chlorobenzene solution as lithium salt B to prepare a hole transport layer coating solution. In addition, the molar ratio A / B of the pyridine compound A to the lithium salt B was 2.08.

[0430] Next, a hole transport layer coating liquid is used to form a hole transport layer of about 550 nm on the electron transport layer adsorbed with the photosensitizing compound by die coating. Then, the end of the glass substrate provided with the sealing member is etched by laser processing, and a through hole for connecting to the ITO / NTO layer serving as the terminal extraction portion is further formed by laser processing, and a through hole for connecting the units in series is formed by laser processing again.

[0431] After a mask was installed between the end of the glass substrate and the cell, silver was vacuum-deposited to form a second electrode of about 70 nm.

[0432] A UV curable resin (WorldRock No. 5910, manufactured by Kyoritsu Chemical Co., Ltd.) is applied to the end of the glass substrate using a dispenser (2300N, manufactured by SUNTTECH) in such a way that the power generation area is surrounded. Then, the dew point is adjusted to -40°C and moved to a glove box into which a nitrogen and oxygen mixed gas (oxygen concentration: 10% by volume) is introduced. A cover glass as the second substrate is placed on the UV curable resin, and after curing it by ultraviolet irradiation, it is heated at 80°C for 60 minutes. As described above, the power generation area is sealed, and finally, a UV cutoff film is attached to the light-receiving surface to produce Figure 3 The photoelectric conversion module 1 of the present invention is shown.

[0433] (Example 2)

[0434] In Example 1, the photoelectric conversion module 2 is prepared in the same manner as in Example 1 except that the photosensitizing compound is changed to the photosensitizing compound shown in B1-2, and the lithium salt is further changed to lithium (fluorosulfonyl) (pentafluoroethanesulfonyl) imide (Li-FPFSI) 69.2 mM, the pyridine compound is changed to 143.8 mM, the organic hole transport material is changed to 159.8 mM, and the cobalt complex is changed to the cobalt complex shown in F-23 12.5 mM.

[0435] (Example 3)

[0436] In Example 1, the photoelectric conversion module 3 is prepared in the same manner as in Example 1 except that the photosensitizing compound is changed to the photosensitizing compound of B1-5, the lithium salt is changed to 73.2 mM, the pyridine compound is changed to 145.3 mM, the organic hole transport material is changed to 161.5 mM, and the cobalt complex is changed to 12.6 mM.

[0437] (Example 4)

[0438] In Example 1, the photosensitizing compound is changed to the photosensitizing compound of B1-9 mentioned above, the lithium salt is changed to 75.7 mM, the pyridine compound is changed to 146.1 mM, the organic hole transport material is changed to 162.3 mM, and the cobalt complex is changed to the cobalt complex shown in F-19 above (manufactured by Greatcell Solar Materials Co., Ltd.) 13.0 mM. Except for this, the photoelectric conversion module 4 is manufactured in the same manner as in Example 1.

[0439] (Example 5)

[0440] In Example 1, the photoelectric conversion module 5 is manufactured in the same manner as in Example 1 except that the photosensitizing compound is changed to the photosensitizing compound of B1-10, the lithium salt is changed to 80.2 mM, the pyridine compound is changed to 144.3 mM, the organic hole transport material is changed to 160.4 mM, and the cobalt complex is changed to 12.5 mM.

[0441] (Example 6)

[0442] In Example 5, a photoelectric conversion module 6 was prepared in the same manner as in Example 5 except that the lithium salt was changed to 85.1 mM, the pyridine compound was changed to 143.7 mM, the organic hole transport material was changed to 159.6 mM, and the cobalt complex was changed to 12.5 mM.

[0443] (Example 7)

[0444] In Example 5, a photoelectric conversion module 7 was prepared in the same manner as in Example 5 except that the lithium salt was changed to 90.0 mM, the pyridine compound was changed to 142.9 mM, the organic hole transport material was changed to 158.8 mM, and the cobalt complex was changed to 12.4 mM.

[0445] (Example 8)

[0446] In Example 5, a photoelectric conversion module 8 was produced in the same manner as in Example 5 except that the lithium salt was changed to 94.8 mM, the pyridine compound was changed to 142.3 mM, the organic hole transport material was changed to 158.1 mM, and the cobalt complex was changed to 12.3 mM.

[0447] (Example 9)

[0448] In Example 5, a photoelectric conversion module 8 was produced in the same manner as in Example 5 except that the lithium salt was changed to 99.6 mM, the pyridine compound was changed to 141.6 mM, the organic hole transport material was changed to 157.3 mM, and the cobalt complex was changed to 12.3 mM.

[0449] (Example 10)

[0450] In Example 1, the photoelectric conversion module 10 is manufactured in the same manner as in Example 1 except that the photosensitizing compound is changed to the photosensitizing compound of B2-2, the lithium salt is changed to 70.6 mM, the pyridine compound is changed to 144.5 mM, the organic hole transport material is changed to 160.5 mM, and the cobalt complex is changed to 13.9 mM.

[0451] (Example 11)

[0452] In Example 10, a photoelectric conversion module 11 was prepared in the same manner as in Example 10 except that the lithium salt was changed to 84.4 mM, the pyridine compound was changed to 142.5 mM, the organic hole transport material was changed to 158.3 mM, and the cobalt complex was changed to 13.7 mM.

[0453] (Example 12)

[0454] In Example 1, a photoelectric conversion module 12 was produced in the same manner as in Example 1 except that the photosensitizing compound was changed to B2-1, the lithium salt was changed to 69.6 mM, the pyridine compound was changed to 144.6 mM, the organic hole transport material was changed to 160.7 mM, and the cobalt complex was changed to 13.9 mM.

[0455] (Example 13)

[0456] In Example 12, a photoelectric conversion module 13 was prepared in the same manner as in Example 12 except that the lithium salt was changed to 89.9 mM, the pyridine compound was changed to 142.7 mM, the organic hole transport material was changed to 158.6 mM, and the cobalt complex was changed to 12.7 mM.

[0457] (Example 14)

[0458] In Example 5, a photoelectric conversion module 14 is prepared in the same manner as in Example 5, except that the lithium salt is changed to 81.8 mM of lithium (fluorosulfonyl) (nonafluorobutylsulfonyl) imide (Li-FNFSI), the pyridine compound is changed to 138.1 mM, the organic hole transport material is changed to 153.4 mM, and the cobalt complex is changed to 12.0 mM of the cobalt complex shown in F-19 above (produced by Greatcell Solar Materials, Inc.).

[0459] (Example 15)

[0460] In Example 5, the photoelectric conversion module 15 is prepared in the same manner as in Example 5, except that the lithium salt is changed to 90.6 mM of lithium (pentafluoroethanesulfonyl) (trifluoromethanesulfonyl) imide (Li-PFTFSI), the pyridine compound is changed to 135.9 mM of the pyridine compound shown in H-3 above, the organic hole transport material is changed to 151.0 mM, and the cobalt complex is changed to 11.8 mM.

[0461] (Comparative Example 1)

[0462] In Example 1, a photoelectric conversion module 16 of Comparative Example 1 was prepared in the same manner as in Example 1 except that no lithium salt was added, the pyridine compound was changed to 145.8 mM, the organic hole transport material was changed to 157.0 mM, and the cobalt complex was changed to 12.6 mM.

[0463] (Comparative Example 2)

[0464] In Example 1, the photoelectric conversion module 17 of Comparative Example 2 was prepared in the same manner as in Example 1 except that the lithium salt was changed to 71.1 mM lithium bis(fluorosulfonyl)imide (Li-FSI), the pyridine compound was changed to 147.8 mM, the organic hole transport material was changed to 164.2 mM, and the cobalt complex was changed to 12.8 mM.

[0465] (Comparative Example 3)

[0466] In Comparative Example 2, the photoelectric conversion module 18 of Comparative Example 3 was prepared in the same manner as Comparative Example 2 except that the lithium salt was changed to 83.7 mM of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), the pyridine compound was changed to 141.3 mM, the organic hole transport material was changed to 157.0 mM, and the cobalt complex was changed to 12.3 mM.

[0467] (Comparative Example 4)

[0468] In Example 1, the photoelectric conversion module 19 of Comparative Example 4 is prepared in the same manner as in Example 1, except that the photosensitizing compound is changed to the photosensitizing compound of B2-1 mentioned above, the lithium salt is changed to 71.1 mM of lithium bis(fluorosulfonyl)imide (Li-FSI), the pyridine compound is changed to 147.8 mM, the organic hole transport material is changed to 164.2 mM, and the cobalt complex is changed to 12.8 mM.

[0469] (Comparative Example 5)

[0470] In Comparative Example 4, the photoelectric conversion module 20 of Comparative Example 5 was prepared in the same manner as Comparative Example 4 except that the lithium salt was changed to 83.7 mM of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), the pyridine compound was changed to 141.3 mM, the organic hole transport material was changed to 157.0 mM, and the cobalt complex was changed to 12.3 mM.

[0471] Next, for each of the produced photoelectric conversion modules, the sealed oxygen concentration and the performance of the photoelectric conversion module (initial maximum output power Pmax1 and Pmax maintenance rate) were evaluated as follows.

[0472] <Sealed oxygen concentration>

[0473] The oxygen concentration inside the seal can be measured using a conventionally known method. For example, there is a method of quantitatively analyzing the relative concentration of the gas components inside the seal using a mass spectrometer, which is effectively used in the present invention. Specifically, the seal of the sample is opened under high vacuum, and the outflowing water and gas are subjected to mass analysis for quantification. As a mass spectrometer, there are quadrupole type and time-of-flight type, and the latter can perform higher sensitivity measurement.

[0474] <Performance Evaluation of Photoelectric Conversion Module>

[0475] The obtained photoelectric conversion module was irradiated with a 5,000K white LED at 200 lx and the IV characteristics were evaluated using a solar cell evaluation system (As-510-PV03, manufactured by NF Circuit Design Co., Ltd.) to determine the initial maximum output power Pmax1 (μW / cm 2Then, the 5,000K white LED was irradiated at 10,000 lx for 1,000 hours, and the IV characteristics were evaluated again under 5,000K white LED irradiation at 200 lx. The maximum output power Pmax2 (μW / cm 2 ) and calculate the Pmax maintenance rate [(Pmax2 / Pmax1)×100](%).

[0476] Table 1

[0477]

[0478]

[0479] Table 2

[0480]

[0481] According to the results of Tables 1 and 2, Examples 1 to 15 can obtain high output even under low illumination by using the photosensitizing compound represented by at least one of the general formula (1) and the general formula (2). In addition, it can be seen that Examples 1 to 15 can maintain high output power for a long time and have excellent durability by containing the lithium salt represented by the general formula (3). It can be considered that the lithium salt represented by the general formula (3) has improved solubility and compatibility due to the asymmetric anion species, and can stably exist in the film even if the added amount is increased, thereby improving durability.

[0482] As embodiments of the present invention, for example, the following are described.

[0483] <1> A photoelectric conversion element having a first electrode, a photoelectric conversion layer and a second electrode, characterized in that: the photoelectric conversion layer includes an electron transport layer and a hole transport layer, the photoelectric conversion layer includes a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3),

[0484] Chemical formula 46

[0485]

[0486] In the general formula (1), Ar1 and Ar2 represent an aryl group which may have a substituent, R1 and R2 represent a linear or branched alkyl group having 4 to 10 carbon atoms, and X represents an arbitrary substituent represented by the following structural formula:

[0487] Chemical formula 47

[0488]

[0489] Chemical formula 48

[0490]

[0491] In the above general formula (2), n represents an integer of 0 or 1, and R3 represents an aryl group which may have a substituent or any substituent represented by the following structural formula.

[0492] Chemical formula 49

[0493]

[0494] Chemical formula 50

[0495]

[0496] Wherein, in the general formula (3), A and B represent any substituent of F, CF3, C2F5, C3F7 and C4F9, and the substituents of A and B are different.

[0497] <2> According to the above <1> In the photoelectric conversion element, the photosensitizing compound represented by the general formula (1) is a compound represented by the following general formula (4).

[0498] Chemical formula 51

[0499]

[0500] In the general formula (4), Ar4 and Ar5 represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent, and Ar6 represents a phenyl group which may have a substituent or a thienyl group which may have a substituent.

[0501] <3> According to the above <1> or <2> In the photoelectric conversion element, the photosensitizing compound represented by the general formula (2) is a compound represented by the following general formula (5).

[0502] Chemical formula 52

[0503]

[0504] In the above general formula (5), n represents an integer of 0 or 1.

[0505] <4> According to the above <1> ~ <3> The photoelectric conversion element described in any one of the preceding claims is characterized in that the lithium salt represented by the general formula (3) is lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide.

[0506] <5> According to the above <1> ~ <4> In the photoelectric conversion element described above, the photoelectric conversion layer includes a trivalent cobalt complex represented by the following general formula (6).

[0507] Chemical formula 53

[0508]

[0509] In the above general formula (6), R4 to R6 represent a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group or a trifluoromethyl group, and X represents any one of the following structural formulas (1) to (4).

[0510] Chemical formula 54

[0511]

[0512] <6> According to the above <1> ~ <5> In any one of the above-mentioned photoelectric conversion elements, the hole transport layer includes a basic compound represented by the following general formula (7).

[0513] Chemical formula 55

[0514]

[0515] In the general formula (7), Ar7 and Ar8 represent an aryl group which may have a substituent.

[0516] <7> According to the above <6> In the photoelectric conversion element, the molar ratio A / B of the alkaline compound A to the lithium salt B is less than 2.0.

[0517] <8> According to the above <1> ~ <7> The photoelectric conversion element described in any one of the above aspects includes a hole blocking layer between the first electrode and the photoelectric conversion layer.

[0518] <9> According to the above <1> to <8> The photoelectric conversion element described in any one of the above aspects includes a sealing member that shields the photoelectric conversion layer from an external environment of the photoelectric conversion element.

[0519] <10> A photoelectric conversion module, characterized in that: <1> to <9> The photoelectric conversion elements described in any one of the above are electrically connected in series or in parallel.

[0520] <11> According to the above <10> The photoelectric conversion module has at least two photoelectric conversion elements adjacent to each other, and the first electrode in one photoelectric conversion element and the second electrode in another photoelectric conversion element are electrically connected via a conductive portion penetrating at least a photoelectric conversion layer.

[0521] <12> according to <10> or <11> The photoelectric conversion module is characterized by having a sealing member for shielding the photoelectric conversion layers of the plurality of photoelectric conversion elements arranged to constitute the photoelectric conversion module from the external environment of the photoelectric conversion module.

[0522] <13> An electronic device, characterized in that it comprises: <1> to <12> At least one of the photoelectric conversion element and the photoelectric conversion module described in any one of the above; and a device that operates using electric power generated by photoelectric conversion of at least one of the photoelectric conversion element and the photoelectric conversion module.

[0523] <14> An electronic device, characterized by comprising: <1> to <12> At least one of the photoelectric conversion element and the photoelectric conversion module described above; a battery capable of storing electricity generated by photoelectric conversion of at least one of the photoelectric conversion element and the photoelectric conversion module, and a device that operates by storing the electricity stored in the battery.

[0524] <15> A power module, characterized by comprising: <10> to <12> The photoelectric conversion module and the power integrated circuit described above.

[0525] Said <1> to <9> The photoelectric conversion element according to any one of the above <10> to <12> The photoelectric conversion module according to any one of the above <13> to <14> The electronic device according to any one of the above <15> The power module described in the specification can solve various problems in the past and achieve the purpose of the present invention.

Claims

1. A photoelectric conversion element having a first electrode, a photoelectric conversion layer and a second electrode, characterized in that : The photoelectric conversion layer includes an electron transport layer and a hole transport layer. The photoelectric conversion layer includes a photosensitizing compound represented by at least one of the following general formula (1) and the following general formula (2), and a lithium salt represented by the following general formula (3), Chemical formula 1 In the general formula (1), Ar1 and Ar2 represent aromatic groups which may have substituents, R1 and R2 represent linear or branched alkyl groups having 4 to 10 carbon atoms, and X represents any substituent represented by the following structural formula: Chemical formula 2 Chemical formula 3 In the above general formula (2), n represents 1, and R3 represents an aromatic group which may have a substituent or any substituent represented by the following structural formula: Chemical formula 4 Chemical formula 5 Wherein, in the general formula (3), A and B represent any substituent of F, CF3, C2F5, C3F7 and C4F9, and the substituents of A and B are different.

2. The photoelectric conversion element according to claim 1, characterized in that: The photosensitizing compound represented by the general formula (1) is a compound represented by the following general formula (4): Chemical formula 6 In the above general formula (4), Ar4 and Ar5 represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent, and Ar6 represents a phenyl group which may have a substituent or a thienyl group which may have a substituent.

3. The photoelectric conversion element according to claim 1 or 2, characterized in that: The photosensitizing compound represented by the general formula (2) is a compound represented by the following general formula (5): Chemical formula 7 In the above general formula (5), n represents 1.

4. The photoelectric conversion element according to claim 1 or 2, characterized in that: The lithium salt represented by the general formula (3) is lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide.

5. The photoelectric conversion element according to claim 1 or 2, characterized in that: The photoelectric conversion layer includes a trivalent cobalt complex represented by the following general formula (6): Chemical formula 8 In the above general formula (6), R4 to R6 represent a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group or a trifluoromethyl group, and X represents any one of the following structural formulas (1) to (4): Chemical formula 9 BF4 …Structure (1) PF6 ...Structure (2) 6. The photoelectric conversion element according to claim 1 or 2, characterized in that: The hole transport layer comprises a basic compound represented by the following general formula (7): Chemical formula 10 In the general formula (7), Ar7 and Ar8 represent an aryl group which may have a substituent.

7. The photoelectric conversion element according to claim 6, characterized in that: The molar ratio of the basic compound to the lithium salt is less than 2.

0.

8. The photoelectric conversion element according to claim 1 or 2, characterized in that: A hole blocking layer is provided between the first electrode and the photoelectric conversion layer.

9. The photoelectric conversion element according to claim 1 or 2, characterized in that: A sealing member is provided for shielding the photoelectric conversion layer from an 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. The photoelectric conversion module according to claim 10, characterized in that: At least two of the photoelectric conversion elements are adjacent to each other, and the first electrode in one of the photoelectric conversion elements and the second electrode in the other photoelectric conversion element are electrically connected via a conductive portion that penetrates at least a photoelectric conversion layer.

12. The photoelectric conversion module according to claim 10 or 11, characterized in that: A sealing member is provided to shield the photoelectric conversion layer of the plurality of arranged photoelectric conversion elements constituting the photoelectric conversion module from the external environment of the photoelectric conversion module.

13. An electronic device, characterized in that include: At least one of the photoelectric conversion element and the photoelectric conversion module according to any one of claims 1 to 12; as well as A device that operates using electric power generated by photoelectric conversion of at least one of the photoelectric conversion element and the photoelectric conversion module.

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

15. A power module, characterized in that include: The photoelectric conversion module according to any one of claims 10 to 12, and Power supply integrated circuit.

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