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

Abstract

A photoelectric conversion element, comprising: a first substrate; a first electrode; a photoelectric conversion layer; a second electrode; and a second substrate, wherein the photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer, the sealing portion is provided so as to surround the periphery of the photoelectric conversion layer, and the width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less.

Description

Technical Field

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

[0002] In recent years, solar cells have become increasingly important as an alternative energy source to fossil fuels or as a measure to combat global warming. Solar cells and photodiodes are obtained by applying a photoelectric conversion element that can convert light energy into electric energy.

[0003] In recent years, indoor-type photoelectric conversion elements, such as light-emitting diodes (LEDs) or fluorescent lamps, that have high power generation performance not only under sunlight (illuminance under direct sunlight: approximately 100,000 lux) but also under low-illuminance light (illuminance: 20 lux or more and 1,000 lux or less) have attracted attention.

[0004] For example, an organic thin-film solar cell provided with a sealing portion so as to surround a photoelectric conversion element has been proposed (for example, refer to PTL1).

[0005] Citation List

[0006] Patent Literature

[0007] PTL1 Japanese Unexamined Patent Application Publication No. 2016-174086 Summary of the Invention

[0008] Technical Problem

[0009] An object of the present disclosure is to provide a photoelectric conversion element that has good photoelectric conversion properties even under low-illuminance light and is excellent in durability against mechanical stress.

[0010] Technical Solution

[0011] According to one aspect of the present disclosure, a photoelectric conversion element includes: a first substrate; a first electrode; a photoelectric conversion layer; a second electrode; and a second substrate. The photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer. The sealing portion is provided so as to surround the periphery of the photoelectric conversion layer. The width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction. The ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less.

[0012] Advantageous Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a photoelectric conversion element that has good photoelectric conversion properties even under low-illuminance light and is excellent in durability against mechanical stress. Brief Description of the Drawings

[0014] Figure 1 It is a schematic diagram showing an example of the cross-section of a photoelectric conversion element according to the first embodiment.

[0015] Figure 2 It is a schematic top view showing an example of a sealing portion in the photoelectric conversion element according to the first embodiment.

[0016] Figure 3 It is a schematic diagram showing another example of a photoelectric conversion element according to the second embodiment.

[0017] Figure 4 It is a schematic diagram showing another example of a photoelectric conversion element according to the third embodiment of the present disclosure.

[0018] Figure 5 It is a schematic diagram showing another example of a photoelectric conversion element according to the fourth embodiment of the present disclosure.

[0019] Figure 6 It is a schematic diagram showing another example of a photoelectric conversion element according to the fifth embodiment.

[0020] Figure 7 It is a schematic diagram showing an example of a photoelectric conversion module according to the present disclosure.

[0021] Figure 8 It is a block diagram of a mouse for a personal computer as an example of an electronic device according to the present disclosure.

[0022] Figure 9 It shows Figure 8 A schematic external view of an example of the mouse shown.

[0023] Figure 10 It is a block diagram of a keyboard for a personal computer as an example of an electronic device according to the present disclosure.

[0024] Figure 11 It shows Figure 10 A schematic external view of an example of the keyboard shown.

[0025] Figure 12 It shows Figure 10 A schematic external view of another example of the keyboard shown.

[0026] Figure 13 It is a block diagram of a sensor as an example of an electronic device according to the present disclosure.

[0027] Figure 14 It is a block diagram of a turntable as an example of an electronic device according to the present disclosure.

[0028] Figure 15 It is a block diagram showing an example of an electronic device according to the present disclosure.

[0029] Figure 16 is a block diagram showing an example of further incorporating a power supply IC into Figure 15 the electronic device shown.

[0030] Figure 17 is a block diagram showing an example of further incorporating a power storage device into Figure 16 the electronic device shown.

[0031] Figure 18 is a block diagram showing an example of the power supply module of the present disclosure.

[0032] Figure 19 is a block diagram showing an example of further incorporating a power storage device Figure 18 into the power supply module shown.

[0033] Figure 20 is a schematic diagram showing a sealing structure having a bent shape in the sealing portion of the photoelectric conversion element of Example 1.

[0034] Figure 21 is a schematic diagram showing a sealing structure having a bent shape in the sealing portion of the photoelectric conversion element of Examples 2 to 9.

[0035] Figure 22 is a schematic diagram showing a sealing structure having a bent shape in the sealing portion of the photoelectric conversion element of Example 19.

[0036] Figure 23 is a schematic diagram showing a wedge-shaped sealing structure in the sealing portion of the photoelectric conversion element of Example 23.

[0037] Figure 24 is a schematic diagram showing the sealing structure of the linear sealing portion of the photoelectric conversion element of Comparative Example 1.

[0038] Figure 25 is a schematic diagram showing the sealing structure of the zigzag sealing portion of the photoelectric conversion element of Comparative Example 2.

[0039] Figure 26 is a schematic diagram showing an example of the sealing portion.

[0040] Figure 27 is a cross-sectional SEM photograph of a region in the missing portion that includes a missing layer. Detailed Description

[0041] (Photoelectric Conversion Element)

[0042] The photoelectric conversion element of the present disclosure includes: a first substrate; a first electrode; a photoelectric conversion layer; a second electrode; and a second substrate. The photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer. The sealing portion is provided so as to surround the periphery of the photoelectric conversion layer. The width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction. The ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less.

[0043] As a result of diligent research, the present inventors have found the following.

[0044] In order to exhibit good photoelectric conversion properties and good stability over time under low-intensity light, it is necessary to provide a sealing portion to prevent oxygen or moisture from entering.

[0045] Meanwhile, in the conventional technology, as shown in the drawings, a sealing portion having the same width is formed. Therefore, it has been confirmed that when mechanical stress (e.g., torsion, load, or drop) is applied thereto, the sealing portion, the substrate, or the photoelectric conversion layer is damaged, thereby significantly reducing the photoelectric conversion properties and the stability over time. There is a problem that it is difficult to achieve good stability over time and good durability against mechanical stress with conventional sealing techniques.

[0046] Therefore, in the present disclosure, when the photoelectric conversion element includes: a first substrate; a first electrode; a photoelectric conversion layer; a second electrode; and a second substrate, wherein the photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer, the sealing portion is provided so as to surround the periphery of the photoelectric conversion layer, and the width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less, good durability against mechanical stress can be satisfied.

[0047] <First Electrode>

[0048] The shape and size of the first electrode are not particularly limited and can be appropriately selected according to the intended purpose.

[0049] The structure of the first electrode is not particularly limited and can be appropriately selected according to the intended purpose. The first electrode may be a single-layer structure or may be a structure in which a plurality of materials are laminated.

[0050] The material of the first electrode is not particularly limited and can be appropriately selected according to the intended purpose as long as it has conductivity and transparency to visible light. Examples of the material include transparent conductive metal oxides, carbon, and metals.

[0051] Examples of the transparent conductive metal oxides include indium tin oxide (hereinafter referred to as "ITO"), tin oxide doped with fluorine (hereinafter referred to as "FTO"), tin oxide doped with antimony (hereinafter referred to as "ATO"), tin oxide doped with niobium (hereinafter referred to as "NTO"), zinc oxide doped with aluminum, indium zinc oxide, and niobium titanium oxide.

[0052] Examples of carbon include carbon black, carbon nanotubes, graphene, and fullerenes.

[0053] Examples of metals include gold, silver, aluminum, nickel, indium, tantalum, and titanium.

[0054] These may be used alone or in combination. Among them, the transparent conductive metal oxides with high transparency are preferred, and ITO, FTO, ATO, and NTO are more preferred.

[0055] The average thickness of the first electrode is not particularly limited and can be appropriately selected according to the intended purpose. The average thickness of the first electrode is preferably 5 nm or more and 100 μm or less, more preferably 50 nm or more and 10 μm or less. When the material of the first electrode is carbon or metal, the average thickness of the first electrode is preferably an average thickness sufficient to obtain light transmittance.

[0056] The first electrode can be formed by known methods such as sputtering, evaporation, and spraying.

[0057] The first electrode is preferably formed on the first substrate. An integrated commercially available product with the first electrode pre-formed on the first substrate can be used.

[0058] Examples of the integrated commercially available products include FTO-coated glass, ITO-coated glass, zinc oxide, aluminum-coated glass, FTO-coated transparent plastic film, and ITO-coated transparent plastic film. Other examples of the integrated commercially available products include a glass substrate provided with a transparent electrode in which tin oxide or indium oxide is doped with cations or anions having different atomic values, and a glass substrate provided with a metal electrode having a structure that allows light to pass through in a mesh or stripe form.

[0059] These can be used alone, or two or more products can be combined and used as a hybrid product or a laminate. In addition, in order to reduce the resistance value, metal leads can also be used in combination.

[0060] The material of the metal lead is, for example, aluminum, copper, silver, gold, platinum, and nickel.

[0061] The metal lead can be formed on the substrate by, for example, vapor deposition, sputtering, or pressure bonding, and a layer of ITO or FTO can be provided thereon for combined use.

[0062] <Photoelectric conversion layer>

[0063] The photoelectric conversion layer may include at least an electron transport layer and a hole transport layer, and may be a single layer or a multilayer in which multiple layers are laminated.

[0064] The photoelectric conversion layer may include a photosensitive compound between the electron transport layer and the hole transport layer.

[0065] <Electron transport layer>

[0066] The photoelectric conversion element includes an electron transport layer containing a photosensitive compound.

[0067] The ionization potential of the photosensitive compound exceeds the ionization potential of the hole transport layer. When the ionization potential of the photosensitive compound exceeds the ionization potential of the hole transport layer, the hole conduction efficiency of the hole transport layer is excellent.

[0068] For the purpose of transporting the electrons generated in the photosensitive compound to the first electrode or the hole blocking layer, the electron transport layer is formed. Therefore, the electron transport layer is preferably disposed adjacent to the first electrode or the hole blocking layer.

[0069] The structure of the electron transport layer is not particularly limited and can be appropriately selected according to the intended purpose. In at least two adjacent photoelectric conversion elements, the electron transport layers may extend to each other, but preferably do not extend to each other. The structure of the electron transport layer may be a single layer or a multilayer in which multiple layers are laminated.

[0070] The electron transport layer includes an electron transport material and, if necessary, other materials.

[0071] The electron transport material is not particularly limited and can be appropriately selected according to the intended purpose. The electron transport material is preferably a semiconductor material.

[0072] Preferably, the semiconductor material has a particulate shape, and these particles are combined to form on a porous film. On the surface of the semiconductor particles constituting the porous electron transport layer, the photosensitive compound is chemically or physically adsorbed.

[0073] The semiconductor material is not particularly limited and known materials can be used. Examples of the semiconductor material include elemental semiconductors, compound semiconductors, and compounds having a perovskite structure.

[0074] Examples of the elemental semiconductor include silicon and germanium.

[0075] Examples of compound semiconductors include chalcogenides of metals. Specific examples thereof include: oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium and lead; and tellurium compounds of cadmium. Other examples of compound semiconductors include: phosphides of zinc, gallium, indium, and cadmium; gallium arsenide; copper indium selenide, and copper indium sulfide.

[0076] Examples of compounds having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate.

[0077] Among them, oxide semiconductors are preferred. In particular, titanium oxide, zinc oxide, tin oxide, and niobium oxide are more preferred. When the electron transport material of the electron transport layer is titanium oxide, the conduction band energy level is high, a high open-circuit voltage can be obtained, and high photoelectric conversion characteristics can be obtained, which is advantageous.

[0078] These can be used alone or in combination. The crystal type of the semiconductor material is not particularly limited and can be appropriately selected according to the intended purpose. The crystal type of the semiconductor material can be single crystal, polycrystalline, or amorphous.

[0079] The average particle size of the primary particles of the semiconductor material is not particularly limited and can be appropriately selected according to the intended purpose. The average particle size is preferably 1 nm or more and 100 nm or less, more preferably 5 nm or more and 50 nm or less. In addition, semiconductor materials having a larger average particle size can also be mixed or laminated, and in some cases, the effect of diffusing incident light may improve the conversion efficiency. In this case, the average particle size is preferably 50 nm or more and 500 nm or less.

[0080] The average thickness of the electron transport layer is not particularly limited and can be appropriately selected according to the intended purpose. The average thickness is preferably 50 nm or more and 100 μm or less, more preferably 100 nm or more and 50 μm or less, and even more preferably 120 nm or more and 10 μm or less. When the average thickness of the electron transport layer falls within the above preferred range, the amount of the photosensitive compound per unit projected area can be sufficiently ensured, and a high light trapping rate can be maintained. In addition, the diffusion distance of the injected electrons hardly increases, and the loss due to charge recombination can be very low. Therefore, an electron transport layer having an average thickness falling within the preferred range is advantageous.

[0081] The production method of the electron transport layer is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the production method include methods of forming a thin film in a vacuum, such as sputtering method and wet film forming method. Among them, in terms of production cost, the wet film forming method is preferred, and the method of preparing a paste of a powder or sol of a dispersed semiconductor material and then coating the paste on the first electrode serving as a collecting electron electrode substrate or more preferably on the hole blocking layer is more preferred.

[0082] The wet film forming method is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the wet film forming method include dipping method, spraying method, wire bar coating method, spin coating method, roll coating method, knife coating method, gravure coating method and die coating method.

[0083] As the wet printing method, for example, various methods such as letterpress printing, offset printing, gravure printing, intaglio printing, flexographic printing and screen printing can be used.

[0084] The method of preparing the dispersion of the semiconductor material is, for example, a method of mechanically pulverizing the semiconductor material using a grinding device known in the art. According to this method, the dispersion of the semiconductor material can be prepared by dispersing the particulate semiconductor material alone or a mixture of the semiconductor material and a resin in water or a solvent.

[0085] Examples of the resin include vinyl compounds (e.g., styrene, vinyl acetate, acrylate and methacrylate), silicone resin, phenoxy resin, polysulfone resin, polyvinyl butyral resin, polyvinyl formal resin, polyester resin, cellulose ester resin, cellulose ether resin, polyurethane resin, phenolic resin, epoxy resin, polycarbonate resin, polyarylate resin, polyamide resin and polyimide resin. These can be used alone or in combination.

[0086] Examples of the solvent include water, alcohol solvent, ketone solvent, ester solvent, ether solvent, amide solvent, halogenated hydrocarbon solvent and hydrocarbon solvent.

[0087] Examples of the alcohol solvent include methanol, ethanol, isopropanol and α-terpineol.

[0088] Examples of the ketone solvent include acetone, methyl ethyl ketone and methyl isobutyl ketone.

[0089] Examples of the ester solvent include ethyl formate, ethyl acetate and n-butyl acetate.

[0090] Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane and dibutyl ether. alkane.

[0091] Examples of the amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0092] Examples of the halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0093] Examples of the hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and isopropylbenzene.

[0094] These can be used alone or in combination.

[0095] An acid, a surfactant, or a chelating agent can be added to a dispersion containing a semiconductor material or a paste containing a semiconductor material obtained by, for example, a sol-gel method to prevent re-aggregation of the particles.

[0096] Examples of the acid include hydrochloric acid, nitric acid, and acetic acid.

[0097] Examples of the surfactant include polyoxyethylene octylphenyl ether.

[0098] Examples of the chelating agent include acetylacetone, 2-aminoethanol, and ethylenediamine.

[0099] In addition, in order to improve the film-forming ability, adding a thickening agent is also an effective means.

[0100] Examples of the thickening agent include polyethylene glycol, polyvinyl alcohol, and ethyl cellulose.

[0101] After coating the semiconductor material, firing, microwave or electron beam irradiation, or electron beam irradiation can be performed so that electrons contact the particles of the semiconductor material or so as to improve the film strength or adhesion to the substrate. These treatments can be performed alone or in combination.

[0102] In the case of firing the electron transport layer formed of the semiconductor material, the firing temperature is not particularly limited and can be appropriately selected according to the intended purpose. However, when the temperature is too high, the resistance of the substrate may become high or the substrate may melt. Therefore, the firing temperature is preferably 30°C or higher and 700°C or lower, more preferably 100°C or higher and 600°C or lower. In addition, the firing time is not particularly limited and can be appropriately selected according to the intended purpose. The firing time is preferably 10 minutes or longer and 10 hours or shorter.

[0103] In the case of irradiating an electron transport layer formed of a semiconductor material with microwaves, the irradiation time is not particularly limited and can be appropriately selected according to the intended purpose. The irradiation time is preferably 1 hour or shorter. In this case, irradiation can be performed from the side where the electron transport layer is formed or from the side where the electron transport layer is not formed.

[0104] After firing an electron transport layer formed of a semiconductor material, for example, chemical plating can be performed using an aqueous titanium tetrachloride solution or a mixed solution with an organic solvent, or electrochemical plating can be performed using an aqueous titanium trichloride solution, in order to increase the surface area of the electron transport layer or improve the electron injection efficiency from a photosensitive compound, which will be described below, to the semiconductor material.

[0105] A film obtained by firing semiconductor materials with a diameter of several tens of nanometers can form a porous structure. This nanoporous structure has an extremely high surface area, and this surface area can be represented by using a roughness coefficient. The roughness coefficient is a numerical value representing the actual area inside the pores relative to the area of the semiconductor particles coated on the first substrate. Therefore, a larger roughness coefficient value is preferred. In terms of the relationship with the average thickness of the electron transport layer, the roughness coefficient is preferably 20 or greater.

[0106] <<Photosensitive compound>>

[0107] The photosensitive compound is adsorbed on the surface of the semiconductor material constituting the electron transport layer in order to further improve the output or the photoelectric conversion efficiency.

[0108] The photosensitive compound is not particularly limited and can be appropriately selected according to the intended purpose, as long as it is a compound that is photoexcited by light emitted to the photoelectric conversion element. Examples of the photosensitive compound include the following known compounds.

[0109] Specific examples thereof include metal complexes and coumarin compounds described in J. Phys. Chem. C, 7224, Vol. 111 (2007), polyene compounds described in Chem. Commun., 4887 (2007), indoline compounds described in J. Am. Chem. Soc., 12218, Vol. 126 (2004), Chem. Commun., 3036 (2003) and Angew. Chem. Int. Ed., 1923, Vol. 47 (2008), thiophene compounds described in J. Am. Chem. Soc., 16701, Vol. 128 (2006) and J. Am. Chem. Soc., 14256, Vol. 128 (2006), cyanine dyes, merocyanine dyes, 9-aryl xanthene compounds, triarylmethane compounds, and phthalocyanine compounds and porphyrin compounds described in J. Phys. Chem., 2342, Vol. 91 (1987), J. Phys. Chem. B, 6272, Vol. 97 (1993), Electroanal. Chem., 31, Vol. 537 (2002), J. Porphyrins Phthalocyanines, 230, Vol. 3 (1999), Angew. Chem. Int. Ed., 373, Vol. 46 (2007) and Langmuir, 5436, Vol. 24 (2008).

[0110] Among them, metal complexes, coumarin compounds, polyene compounds, indoline compounds and thiophene compounds are preferred. Compounds represented by the following structural formulas (1), (2) and (3) and available from MITSUI BISHI PAPER MILLS LIMITED, and in addition, compounds represented by the following general formula (3) are more preferred. These photosensitive compounds can be used alone or in combination.

[0111] [Chemical formula 1]

[0112]

[0113] [Chemical formula 2]

[0114]

[0115] [Chemical formula 3]

[0116]

[0117] [Chemical formula 4]

[0118]

[0119] In general formula (3), X1 and X2 each represent an oxygen atom, a sulfur atom, or a selenium atom, and R1 represents a methine group which may have a substituent. Specific examples of the substituent include aryl groups (e.g., phenyl and naphthyl) and heterocycles (e.g., thienyl and furyl).

[0120] R2 represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent. Examples of the alkyl group include methyl, ethyl, 2-propyl, and 2-ethylhexyl. Examples of the aryl group and the heterocyclic group include the groups exemplified above.

[0121] R3 represents an acid group such as a carboxylic acid, a sulfonic acid, a phosphonic acid, a boric acid, or a phenol, and Z1 and Z2 each represent a substituent forming a cyclic structure.

[0122] Examples of Z1 include fused hydrocarbon group compounds (e.g., benzene ring and naphthalene ring) and heterocycles (e.g., thiophene ring and furan ring), each of which may have a substituent. Specific examples of the substituent include the alkyl groups and alkoxy groups described above (e.g., methoxy, ethoxy, and 2-isopropoxy).

[0123] Examples of Z2 include the following (A-1) to (A-22).

[0124] [Chemical formula 5]

[0125]

[0126] Specific examples of the photosensitive compound containing general formula (3) include, but are not limited to, the following (B-1) to (B-36).

[0127] [Chemical formula 6]

[0128]

[0129] [Chemical formula 7]

[0130]

[0131] [Chemical formula 8]

[0132]

[0133] [Chemical formula 9]

[0134]

[0135] As a method of adsorbing a photosensitive compound on the surface of a semiconductor material in an electron transport layer, for example, a method of immersing an electron transport layer containing a semiconductor material in a solution of a photosensitive compound or a dispersion of a photosensitive compound, and a method of coating and adsorbing a solution of a photosensitive compound or a dispersion of a photosensitive compound on the electron transport layer can be used. In the case of the method of immersing an electron transport layer on which a semiconductor material is formed in a solution of a photosensitive compound or a dispersion of a photosensitive compound, an immersion method, a dipping method, a roll method, or an air knife method can be used. In the case of the method of coating and adsorbing a solution of a photosensitive compound or a dispersion of a photosensitive compound on the electron transport layer, a wire bar coating method, a slide hopper coating method, an extrusion coating method, a curtain coating method, a spin coating method, or a spray coating method can be used. In addition, the photosensitive compound can also be adsorbed in a supercritical fluid such as carbon dioxide.

[0136] When the photosensitive compound is adsorbed on the semiconductor material, a condensing agent can be used in combination.

[0137] The condensing agent can be a reagent that exhibits such a catalytic function of physically or chemically binding the photosensitive compound to the surface of the semiconductor material, or can be a reagent that acts stoichiometrically and favorably shifts the chemical equilibrium. In addition, a thiol or a hydroxy compound can be added thereto as a condensation aid.

[0138] Examples of the solvent for dissolving or dispersing the photosensitive compound include water, an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, an amide solvent, a halogenated hydrocarbon solvent, and a hydrocarbon solvent.

[0139] Examples of the alcohol solvent include methanol, ethanol, and isopropyl alcohol.

[0140] Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0141] Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate.

[0142] Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and di ane.

[0143] Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0144] Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0145] Examples of hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene.

[0146] These may be used alone or in combination.

[0147] Depending on the type of photosensitive compound, there are photosensitive compounds that function more effectively in preventing aggregation between compounds. Therefore, aggregation dissociating agents can be used in combination.

[0148] The aggregation dissociating agent is not particularly limited and can be appropriately selected according to the dye used. Preferred examples of the aggregation dissociating agent include steroidal compounds (e.g., cholic acid and chenodeoxycholic acid), long-chain alkyl carboxylic acids, or long-chain alkyl phosphonic acids.

[0149] The amount of the aggregation dissociating agent is preferably 0.01 parts by mass or more and 500 parts by mass or less, more preferably 0.1 parts by mass or more and 100 parts by mass or less, relative to 1 part by mass of the photosensitive compound.

[0150] The temperature when the photosensitive compound or the photosensitive compound and the aggregation dissociating agent are adsorbed on the surface of the semiconductor material constituting the electron transport layer is preferably -50°C or higher and 200°C or lower. The adsorption time is preferably 5 seconds or longer and 1000 hours or shorter, more preferably 10 seconds or longer and 500 hours or shorter, even more preferably 1 minute or longer and 150 hours or shorter. The adsorption step is preferably carried out in the dark. In addition, the adsorption step can be carried out with standing or stirring.

[0151] The stirring method is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the stirring method include methods using, for example, a stirrer, a ball mill, a paint conditioner, a sand mill, a grinder, a disperser, and an ultrasonic disperser.

[0152] <Hole transport layer>

[0153] The photoelectric conversion element includes a hole transport layer.

[0154] The hole transport layer preferably contains a p-type semiconductor material and a basic compound.

[0155] The hole transport layer includes a p-type semiconductor material in order to obtain the function of transporting holes.

[0156] The ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material. When the ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material, stability over time and high photovoltaic conversion properties can be achieved even under low-intensity light.

[0157] <<p-type semiconductor material>>

[0158] The p-type semiconductor material is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the p-type semiconductor material include inorganic p-type semiconductor materials and organic p-type semiconductor materials.

[0159] The inorganic p-type semiconductor material is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the inorganic p-type semiconductor material include CuSCN, CuI, CuBr, NiO, V2O5, and graphene oxide. Among them, organic p-type semiconductor materials are preferred.

[0160] The organic p-type semiconductor material is not particularly limited and can be appropriately selected according to the intended purpose. For example, known organic p-type semiconductor materials can be used.

[0161] Examples of known organic p-type semiconductor materials include diazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, diazole compounds, tetraarylbiphenylamine compounds, stilbene compounds, and spiro compounds. These can be used alone or in combination. Among them, spiro compounds are preferred.

[0162] Examples of the spiro compound include compounds containing the following general formula (4).

[0163] [Chemical formula 10]

[0164]

[0165] In the general formula (4), R4 to R7 represent substituted amino groups such as dimethylamino, diphenylamino, or naphthyl-4-tolylamino.

[0166] The spiro compound is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the spiro compound include, but are not limited to, exemplary compounds (D-1) to (D-20). These can be used alone or in combination.

[0167] [Chemical formula 11]

[0168]

[0169] [Chemical formula 12]

[0170]

[0171] [Chemical Formula 13]

[0172]

[0173] [Chemical Formula 14]

[0174]

[0175] [Chemical Formula 15]

[0176]

[0177] [Chemical Formula 16]

[0178]

[0179] [Chemical Formula 17]

[0180]

[0181] Since two benzidine backbone molecules are helically bound in the helical compound, an approximately spherical electron cloud is formed, and the hopping conductivity between molecules is excellent. Therefore, the helical compound exhibits excellent optoelectronic conversion characteristics. In addition, the helical compound is highly soluble and dissolves in various organic solvents. Since the helical compound is amorphous (an amorphous substance without a crystal structure), the helical compound tends to densely fill the porous electron transport layer. Since the helical compound does not absorb light of 450 nm or longer, the light absorption of the photosensitizing compound can be effectively carried out, which is particularly preferred for solid dye-sensitized solar cells.

[0182] [[Basic Compound]]

[0183] The hole transport layer contains a basic compound.

[0184] It is believed that the basic compound exists at the boundary near the electron transport layer to prevent back electron transfer from the electron transport layer (i.e., electron transfer from the electron transport layer to the hole transport layer).

[0185] The basic compound is preferably a basic compound represented by the following general formula (A) or general formula (B), more preferably a tertiary amine compound represented by the following general formula (1) and general formula (2). It is advantageous to include a basic compound represented by the following general formula (A) or general formula (B) in the hole transport layer because a high open-circuit voltage and high photoelectric conversion characteristics can be obtained. When the hole transport layer contains at least one selected from the tertiary amine compounds represented by general formula (1) and the tertiary amine compounds represented by general formula (2), high photoelectric conversion characteristics and stability over time can be achieved even under low-intensity light.

[0186] [Chemical formula 18]

[0187]

[0188] (In general formula (A), R1 and R2 each independently represent an alkyl group or an aromatic hydrocarbon group and represent the same or different groups, or R1 and R2 are connected to each other to represent a heterocyclic group containing a nitrogen atom.)

[0189] [Chemical formula 19]

[0190]

[0191] (In general formula (B), R1 and R2 each independently represent an alkyl group or an aromatic hydrocarbon group and represent the same or different groups, or R1 and R2 are connected to each other to represent a heterocyclic group containing a nitrogen atom.)

[0192] [Chemical formula 20]

[0193]

[0194] [Chemical formula 21]

[0195]

[0196] Here, in general formula (1) and general formula (2), Ar1 and Ar2 represent aryl groups that may have substituents, and Ar1 and Ar2 may be the same or different and may be connected to each other.

[0197] Specific example compounds of the basic compounds represented by general formula (A) and general formula (B) are presented below, but the present disclosure is not limited thereto.

[0198] [Chemical formula 22]

[0199]

[0200] [Chemical formula 23]

[0201]

[0202] Specific examples of the tertiary amine compounds represented by the general formula (1) and the general formula (2) include, but are not limited to, the compounds C-1 to C-20 of the following examples. These can be used alone or in combination.

[0203] [Chemical formula 24]

[0204]

[0205] [Chemical formula 25]

[0206]

[0207] [Chemical formula 26]

[0208]

[0209] [Chemical formula 27]

[0210]

[0211] The amount of the basic compound in the hole transport layer is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 30 parts by mass or less, relative to the total amount of the hole transport material. When the amount of the basic compound falls within the preferred range, a high open-circuit voltage can be maintained, a high output can be obtained, and high stability and durability can be obtained even when used for a long time under various environments.

[0212] The molecular weight of the basic compound is preferably 140 g / mol or more. When the molecular weight of the basic compound is 140 g / mol or more, since the basic compound exists at the boundary near the electron transport layer, the electron transport layer and the hole transport layer can be prevented from contacting each other chemically and physically, and the reverse electron transfer can be further reduced. Therefore, high photoelectric conversion characteristics can be exhibited even under low-intensity light.

[0213] The form of the hole transport layer is not particularly limited and can be appropriately selected according to the intended purpose as long as it has the function of transporting holes. Examples of the form of the hole transport layer include: an electrolytic solution obtained by dissolving a redox pair in an organic solvent; a gel electrolyte obtained by immersing in a polymer matrix—a liquid obtained by dissolving a redox pair in an organic solvent; a molten salt containing a redox pair; and a solid electrolyte. These can be used alone or in combination.

[0214] <<Oxidizing agent>>

[0215] The hole transport layer preferably contains an oxidizing agent. When the hole transport layer contains an oxidizing agent, a part of the organic hole transport material becomes a radical cation. Therefore, the conductivity can be improved, and the stability or durability of the output characteristics can be enhanced.

[0216] When the oxidizing agent oxidizes the organic hole transporting material, it exhibits good hole conductivity and can prevent the elimination (reduction) of the oxidized state affected by the surrounding environment of the photoelectric conversion layer, which exhibits good stability over time.

[0217] The oxidizing agent is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the oxidizing agent include tris(4-bromophenyl)ammonium hexachloroantimonate, silver hexafluoroantimonate, nitrosyl tetrafluoroborate , silver nitrate, and metal complexes. These can be used alone or in combination. Among them, metal complexes are preferred.

[0218] Examples of the metal complex include a composition containing, for example, a metal cation, a ligand, and an anion.

[0219] The metal cation is not particularly limited and is appropriately selected according to the intended purpose. Examples of the metal cation include, for example, cations of chromium, manganese, zinc, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, vanadium, gold, and platinum. Among them, cations of manganese, zinc, iron, cobalt, nickel, copper, ruthenium, silver, and vanadium are preferred, and cobalt complexes are more preferred.

[0220] The ligand preferably includes a 5-membered heterocycle and / or a 6-membered heterocycle - which contains at least one nitrogen and may include substituents. Specific examples thereof include, but are not limited to, the following.

[0221] [Chemical formula 28]

[0222]

[0223] [Chemical formula 29]

[0224]

[0225] [Chemical formula 30]

[0226]

[0227] Examples of the anion include hydride ion (H - ), fluoride ion (F - ), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ), hydroxide ion (OH - ), cyanide ion (CN - ), nitrate ion (NO3 - ), nitrite ion (NO2 - ), hypochlorite ion (ClO - ), chlorite ion (ClO2- ) Chlorate ion (ClO3 - ) Perchlorate ion (ClO4 - ) Permanganate ion (MnO4 - ) Acetate ion (CH3COO - ) Bicarbonate ion (HCO3 - ) Dihydrogen phosphate ion (H2PO4 - ) Hydrogen sulfate ion (HSO4 - ) Hydrogen sulfide ion (HS - ) Thiocyanate ion (SCN - ) Tetrafluoroborate ion (BF4 - ) Hexafluorophosphate ion (PF6 - ) Tetracyano borate ion (B(CN)4 - ) Dicyanamide ion (N(CN)2 - ) p-Toluenesulfonate ion (TsO - ) Trifluoromethanesulfonate ion (CF3SO2 - ) Bis(trifluoromethylsulfonyl)amide ion (N(SO2CF3))2 - ) Tetrahydroxy aluminate ion ([Al(OH)4] - or [Al(OH)4(H2O)2] - ) Dicyanoargentate(I) ion ([Ag(CN)2] - ) Tetrahydroxy chromate(III) ion ([Cr(OH)4] - ) Tetrachloroaurate(III) ion ([AuCl4] - ) Oxide ion (O2 - ) Sulfide ion (S2 - ) Peroxide ion (O2 2- ) Sulfate ion (SO4 2- ) Sulfite ion (SO3 2- ) Thiosulfate (S2O3 2- ) Carbonate ion (CO3 2- ) Chromate ion (CrO4 2- ) Dichromate ion (Cr2O7 2- ) Hydrogen phosphate ion (HPO4 2- ) Tetrahydroxy zincate(II) ion ([Zn(OH)4] 2- ) Tetracyano zincate(II) ion ([Zn(CN)4] 2- ) Tetrachlorocuprate(II) ion ([CuCl4] 2- ) Phosphate ion (PO4 3- ) Hexacyanoferrate(III) ion ([Fe(CN)6]3- ) Silver(I) bis(thiosulfato)argentate(III) ion ([Ag(S2O3)2] 3- ) and hexacyanoferrate(II) ion ([Fe(CN)6] 4- ). Among them, tetrafluoroborate ion, hexafluorophosphate ion, tetracyano-borate ion, bis(trifluoromethylsulfonyl)amide ion, and perchlorate ion are preferred.

[0228] The metal complex is particularly preferably a trivalent cobalt complex represented by the following general formula (5). When the metal complex is a trivalent cobalt complex, it has excellent function as an oxidizing agent, which is advantageous.

[0229] [Chemical formula 31]

[0230]

[0231] In the general formula (5), R8 to R 10 represent a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group, or a trifluoromethyl group. X represents one selected from the above anions.

[0232] Specific examples of the cobalt complex represented by the general formula (5) are described below. However, the present disclosure is not limited thereto. These can be used alone or in combination.

[0233] [Chemical formula 32]

[0234]

[0235] [Chemical formula 33]

[0236]

[0237] As the metal complex, a trivalent cobalt complex represented by the following general formula (6) is also effectively used.

[0238] [Chemical formula 34]

[0239]

[0240] In the general formula (6), R 11 and R 12 represent a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group, or a trifluoromethyl group. X represents one selected from the above anions.

[0241] Specific examples of the cobalt complex represented by the general formula (6) are described below. However, the present disclosure is not limited thereto. These can be used alone or in combination.

[0242] [Chemical formula 35]

[0243]

[0244] With respect to 100 parts by mass of the hole transport material, the amount of the oxidizing agent is preferably 0.5 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less. It is not necessary to oxidize all of the hole transport material by adding the oxidizing agent, and it is effective as long as only a part of the hole transport material is oxidized.

[0245] <<alkali metal salt>>

[0246] The hole transport layer preferably contains an alkali metal salt as an additive. This is advantageous because charge transfer can be smooth and good photoelectric conversion characteristics can be obtained.

[0247] It is believed that the cations of the alkali metal salt are present at the boundary near the electron transport layer, and the anions of the alkali metal salt are doped in the hole transport layer.

[0248] Examples of the alkali metal salt include: lithium salts such as lithium chloride, lithium bromide, lithium iodide, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium diisopropylimide, lithium acetate, lithium tetrafluoroborate, lithium pentafluorophosphate, and lithium tetracyanoborate; sodium salts such as sodium chloride, sodium bromide, sodium iodide, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium acetate, sodium tetrafluoroborate, sodium pentafluorophosphate, and sodium tetracyanoborate; and potassium salts such as potassium chloride, potassium bromide, potassium iodide, and potassium perchlorate. Among them, lithium bis(trifluoromethanesulfonyl)imide and lithium diisopropylimide are preferred.

[0249] With respect to 100 parts by mass of the hole transport material, the amount of the alkali metal salt is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less.

[0250] The hole transport layer may have a single-layer structure formed of a single material or may have a laminated structure including a plurality of compounds. When the hole transport layer has a laminated structure, a polymer material is preferably used in the hole transport layer near the second electrode. It is advantageous to use a polymer material having excellent film-forming properties because the surface of the porous electron transport layer can be made smoother and the photoelectric conversion characteristics can be improved. In addition, the polymer material is not easily infiltrated into the interior of the porous electron transport layer. Therefore, the polymer material has excellent properties of covering the surface of the porous electron transport layer, and can achieve the effect of preventing short circuit when setting the electrode.

[0251] The polymer material for the hole transport layer is not particularly limited. Examples of the polymer material include known hole transport polymer materials.

[0252] Examples of the hole transport polymer material include polythiophene compounds, poly(phenylene vinylene) compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiadiazole compounds.

[0253] Examples of polythiophene compounds include poly(3 - n - hexylthiophene), poly(3 - n - octyloxythiophene), poly(9,9'-dioctyl - fluorene - co - bithiophene), poly(3,3”'-didodecyl - quaterthiophene), poly(3,6 - dioctylthieno[3,2 - b]thiophene), poly(2,5 - bis(3 - decylthiophen - 2 - yl)thieno[3,2 - b]thiophene), poly(3,4 - didecylthiophene - co - thieno[3,2 - b]thiophene), poly(3,6 - dioctylthieno[3,2 - b]thiophene - co - thieno[3,2 - b]thiophene), poly(3,6 - dioctylthieno[3,2 - b]thiophene - co - thiophene), and poly(3,6 - dioctylthieno[3,2 - b]thiophene - co - bithiophene).

[0254] Examples of poly(phenylene vinylene) compounds include poly[2 - methoxy - 5 - (2 - ethylhexyl)oxy - 1,4 - phenylene vinylene], poly[2 - methoxy - 5 - (3,7 - dimethyloctyloxy) - 1,4 - phenylene vinylene], and poly[(2 - methoxy - 5 - (2 - ethylhexyl)oxy - 1,4 - phenylene vinylene) - co - (4,4'-biphenylene vinylene)].

[0255] Examples of polyfluorene compounds include poly(9,9'-didodecylfluorenyl - 2,7 - diyl), poly[(9,9 - dioctyl - 2,7 - divinylenefluorene) - alt - co - (9,10 - anthracene)], poly[(9,9 - dioctyl - 2,7 - divinylenefluorene) - alt - co - (4,4'-biphenylene)], poly[(9,9 - dioctyl - 2,7 - divinylenefluorene) - alt - co - (2 - methoxy - 5 - (2 - ethylhexyl)oxy - 1,4 - phenylene)], and poly[(9,9 - dioctyl - 2,7 - diyl) - co - (1,4 - (2,5) - dihexyloxy)benzene].

[0256] Examples of polyphenylene compounds include poly[2,5 - dioctyloxy - 1,4 - phenylene] and poly[2,5 - bis(2 - ethylhexyl)oxy - 1,4 - phenylene].

[0257] Examples of polyarylamine compounds include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alternating-co-(N,N'-diphenyl)-N,N'-bis(p-hexylphenyl)-1,4-diaminobenzene], poly[(9,9-dioctylfluorenyl-2,7-diyl)-alternating-co-(N,N'-bis(4-octoxyphenyl)benzidine-N,N'-(1,4-phenylene)], poly[(N,N'-bis(4-octoxyphenyl)benzidine-N,N'-(1,4-phenylene)], poly[(N,N'-bis(4-(2-ethylhexoxy)phenyl)benzidine-N,N'-(1,4-phenylene)], poly[phenylimino-1,4-phenylenevinylene-2,5-dioctoxy-1,4-phenylenevinylene-1,4-phenylene], poly[p-toluoyl imino-1,4-phenylenevinylene-2,5-bis(2-ethylhexoxy)-1,4-phenylenevinylene-1,4-phenylene], and poly[4-(2-ethylhexoxy)phenylimino-1,4-phenylene].

[0258] Examples of polythiadiazole compounds include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alternating-co-(1,4-benzo(2,1',3)thiadiazole] and poly(3,4-didecylthiophene)-co-(1,4-benzo(2,1',3)thiadiazole).

[0259] Among them, polythiophene compounds and polyarylamine compounds are preferred in terms of carrier mobility and ionization potential.

[0260] Various additives can be added to the hole transport material.

[0261] Examples of additives include basic compounds and alkali metal salts such as metal iodides (e.g., iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, and silver iodide), quaternary ammonium salts (e.g., tetraalkylammonium iodide and pyridinium iodide ), metal bromides (e.g., lithium bromide, sodium bromide, potassium bromide, cesium bromide, and calcium bromide), bromides of quaternary ammonium compounds (e.g., tetraalkylammonium bromide and pyridinium bromide ), metal chlorides (e.g., copper chloride and silver chloride), metal acetates (e.g., copper acetate, silver acetate, and palladium acetate), metal sulfates (e.g., copper sulfate and zinc sulfate), metal complexes (e.g., ferrocyanide-ferricyanide and ferrocene-ferrocenium ion), sulfur compounds (e.g., sodium polysulfide and alkylthiol-alkyl disulfide), viologen dyes, hydroquinone, ionic liquids described in Inorg. Chem. 35(1996)1168 (e.g., 1,2-dimethyl-3-n-propylimidazolium iodide , 1-methyl-3-n-hexylimidazolium iodide , 1,2-dimethyl-3-ethylimidazole trifluoromethanesulfonate, 1-methyl-3-butylimidazole nonafluorobutanesulfonate and 1-methyl-3-ethylimidazole bis(trifluoromethyl)sulfonimide), pyridine, 4-tert-butylpyridine, benzimidazole and its derivatives.

[0262] The average thickness of the hole transport layer is not particularly limited and can be appropriately selected according to the intended purpose. The hole transport layer preferably has a structure in which the hole transport layer enters the pores of the porous electron transport layer. A hole transport layer with an average thickness of 0.01 μm or more and 20 μm or less is preferably provided on the electron transport layer, a hole transport layer with an average thickness of 0.1 μm or more and 10 μm or less is more preferably provided on the electron transport layer, and a hole transport layer with an average thickness of 0.2 μm or more and 2 μm or less is still more preferably provided on the electron transport layer.

[0263] The hole transport layer can be directly formed on the electron transport layer that adsorbs the photosensitive compound. The method for producing the hole transport layer is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include methods for forming a thin film under vacuum, such as vacuum deposition and wet film formation. Among them, in particular, the wet film formation method is preferred, and in terms of production cost, the method of coating on the electron transport layer is preferred.

[0264] When using the wet film formation method, the coating method is not particularly limited and can be carried out according to methods known in the art. Examples thereof include dipping, spraying, wire bar coating, spin coating, roll coating, knife coating, gravure coating, and die coating. Examples of wet printing methods include various methods such as letterpress printing, offset printing, gravure printing, intaglio printing, flexography, and screen printing.

[0265] The film can be formed in a supercritical fluid or subcritical fluid at a temperature and pressure below the critical point. The supercritical fluid is not particularly limited and can be appropriately selected according to the intended purpose, as long as it is a non-condensable high-density fluid in a temperature and pressure region exceeding the limit (critical point) where gas and liquid can coexist, does not condense even under compression, and is a fluid in a state equal to or higher than the critical temperature and critical pressure. The supercritical fluid is preferably a supercritical fluid with a low critical temperature.

[0266] Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, and ether solvents.

[0267] Examples of the alcohol solvent include methanol, ethanol, and n-butanol.

[0268] Examples of hydrocarbon solvents include ethane, propane, 2,3-dimethylbutane, benzene, and toluene. Examples of halogen solvents include dichloromethane and chlorotrifluoromethane.

[0269] Examples of ether solvents include dimethyl ether.

[0270] These can be used alone or in combination.

[0271] Among them, since carbon dioxide has a critical pressure of 7.3 MPa and a critical temperature of 31 °C, it can easily generate a supercritical state, is non-flammable, and is easy to handle, so it is preferred.

[0272] The subcritical fluid is not particularly limited and can be appropriately selected according to the intended purpose, as long as it exists as a high-pressure liquid in the temperature and pressure region near the critical point. Compounds that are examples of supercritical fluids can be appropriately used as subcritical fluids.

[0273] The critical temperature and critical pressure of the supercritical fluid are not particularly limited and can be appropriately selected according to the intended purpose. Its critical temperature is preferably -273 °C or higher and 300 °C or lower, more preferably 0 °C or higher and 200 °C or lower.

[0274] In addition to supercritical fluids and subcritical fluids, organic solvents or entrainers can also be used in combination. By adding an organic solvent or an entrainer, the solubility in the supercritical fluid can be more easily adjusted.

[0275] The organic solvent is not particularly limited and can be appropriately selected according to the intended purpose. Examples thereof include ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents.

[0276] Examples of ketone solvents include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0277] Examples of ester solvents include ethyl formate, ethyl acetate, and n-butyl acetate.

[0278] Examples of ether solvents include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and di alkane.

[0279] Examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0280] Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene.

[0281] Examples of hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and isopropylbenzene.

[0282] These can be used alone or in combination.

[0283] After laminating a hole transport material on an electron transport layer on which a photosensitive compound has been adsorbed, a pressing treatment step can be performed. The pressing treatment allows the hole transport material to further adhere to the electron transport layer that is a porous electrode, which can improve the efficiency.

[0284] The method of the pressing treatment is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include a pressing molding method using a plate typified by an IR tablet molding device and a roll pressing method using a roll.

[0285] The pressure is preferably 10 kgf / cm 2 or greater, more preferably 30 kgf / cm 2 or greater.

[0286] The time of the pressing treatment is not particularly limited and can be appropriately selected according to the intended purpose. The time is preferably 1 hour or shorter. Additionally, heat can also be applied during the pressing treatment. A release agent can be provided between the press and the electrode during the pressing treatment.

[0287] Examples of the release agent include fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, perfluoroalkoxy fluororesin, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, and polyvinyl fluoride. These can be used alone or in combination.

[0288] After the pressing treatment step but before setting the second electrode, a metal oxide can be provided between the hole transport material and the second electrode.

[0289] Examples of the metal oxide include molybdenum oxide, tungsten oxide, vanadium oxide, and nickel oxide. These can be used alone or in combination. Among them, molybdenum oxide is preferred.

[0290] The method of providing the metal oxide on the hole transport layer is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include a method of forming a thin film in a vacuum (e.g., sputtering method and vacuum vapor deposition method), and a wet film forming method.

[0291] The wet film-forming method is preferably a method of preparing a paste obtained by dispersing a powder or sol of a metal oxide and coating the paste on the hole transport layer. In the case of using the wet film-forming method, the coating method is not particularly limited and can be carried out according to methods known in the art. Examples of the coating method include dip coating, spray coating, wire bar coating, spin coating, roll coating, knife coating, gravure coating, and die coating. As the wet printing method, various methods such as letterpress printing, offset printing, gravure printing, intaglio printing, flexographic printing, and screen printing can be used.

[0292] The average thickness of the coated metal oxide is preferably 0.1 nm or more and 50 nm or less, more preferably 1 nm or more and 10 nm or less.

[0293] <Second electrode>

[0294] The photoelectric conversion element includes a second electrode.

[0295] The second electrode can be formed on the hole transport layer or on the metal oxide on the hole transport layer. The same electrode as the first electrode can be used in the second electrode. When the strength can be sufficiently maintained, a carrier is not always required.

[0296] Examples of the material of the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers.

[0297] Examples of the metals include platinum, gold, silver, copper, and aluminum.

[0298] Examples of the carbon compounds include graphite, fullerenes, carbon nanotubes, and graphene.

[0299] Examples of the conductive metal oxides include ITO, FTO, and ATO.

[0300] Examples of the conductive polymers include polythiophene and polyaniline.

[0301] These can be used alone or in combination.

[0302] The method of providing these metal oxides on the hole transport material is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include methods of forming a thin film under vacuum, such as sputtering or vacuum deposition; and the wet film-forming method.

[0303] The wet film-forming method is preferably a method of preparing a paste in which a powder or sol of a metal oxide is dispersed, and then coating the paste on the hole transport layer.

[0304] When using the wet film-forming method, the coating method is not particularly limited and can be carried out according to methods known in the art.

[0305] Examples thereof include an impregnation method, a spraying method, a wire bar method, a spin coating method, a roll coating method, a doctor blade coating method, an intaglio coating method, and a die coating method. Examples of wet printing methods include various methods such as letterpress printing, offset printing, intaglio printing, line engraving intaglio printing, flexographic printing, and screen printing. The film thickness is preferably 0.1 nm or more and 50 nm or less, more preferably 1 nm or more and 10 nm or less.

[0306] The second electrode is newly provided after forming the hole transport layer or on the above metal oxide.

[0307] In the second electrode, generally the same electrode as the first electrode can be used. In a structure where strength or airtightness is sufficiently ensured, a carrier is not always required.

[0308] The second electrode can be appropriately formed on the hole transport layer by methods such as a coating method, a lamination method, a deposition method, a CVD method, and a pasting method, depending on the type of material used and the type of hole transport layer.

[0309] In the photoelectric conversion element, preferably, at least one of the first electrode and the second electrode is substantially transparent. Preferably, one side of the first electrode is transparent, and a method of receiving incident light from the side of the first electrode is used. In this case, preferably, a material that reflects light is used on one side of the second electrode, and preferably, glass, plastic, or a metal thin film on which a metal or a conductive oxide is deposited is used. In addition, providing an antireflection layer on the side to receive incident light is an effective means.

[0310] <Sealing portion>

[0311] Preferably includes a sealing portion configured to shield at least the photoelectric conversion layer from the external environment.

[0312] The sealing portion is held by a pair of substrates, at least the electron transport layer and the hole transport layer can be shielded from the external environment, and the sealing portion of the photoelectric conversion element may include a hollow portion.

[0313] The position of the sealing member is not particularly limited and can be appropriately selected according to the intended purpose, as long as the sealing member is provided at a position where at least the electron transport layer and the hole transport layer are shielded from the external environment. For example, the sealing member can be provided on the entire surface to cover the electron transport layer, the hole transport layer, and the second electrode. Alternatively, a substrate can be provided above the second electrode, and the sealing member can be provided at the outer edge of the substrate so as to attach the sealing member to at least one of the first substrate, the first electrode, and the hole blocking layer.

[0314] In a configuration where a substrate is provided as described later and a sealing member is provided at the outer edge of the substrate, a hollow portion can be provided inside the photoelectric conversion element or the photoelectric conversion module. The hollow portion can control oxygen and humidity and effectively improve output or durability.

[0315] When the sealing portion and the photoelectric conversion layer are in contact with each other, when the photoelectric conversion element is deformed due to mechanical stress, the photoelectric conversion layer may be broken (peeled or cracked) due to the stretching of the sealing portion. In terms of durability over time, uncured monomer components and the like may flow out of the sealing portion over time to erode the photoelectric conversion layer.

[0316] Therefore, in the present disclosure, the sealing portion is provided so as to surround the periphery of the photoelectric conversion layer. As Figure 26 described, the width of the sealing portion 9 provided on each side has a minimum width A and a maximum width B in the width direction. The minimum width A and the maximum width B are given at the boundary of the sealing portion or in the main body of the sealing portion. The ratio (B / A) of the maximum width B to the minimum width A is preferably 1.02 or more and 5.0 or less, more preferably 1.09 or more and 3.0 or less. When the ratio (B / A) is 1.02 or more and 5.0 or less, the displacement amount becomes larger according to the deformation of the photoelectric conversion element due to mechanical stress, and the durability against mechanical stress can be improved while maintaining high durability against high temperature and high humidity.

[0317] The distance C between the sealing portion and the second electrode is preferably 30 μm or more, more preferably 50 μm or more, still more preferably 100 μm or more. A distance C of 30 μm or more is advantageous because even when monomer components ooze out from the sealing resin, they hardly reach the power generation layer.

[0318] The minimum width A, the maximum width B, and the distance C can be measured by, for example, an optical microscope and a microscope.

[0319] The shape of the sealing portion in the width direction is not particularly limited as long as the range of the ratio (B / A) and the distance C are satisfied. Examples of the shape include a curved shape, a rectangular shape, and a wedge shape. These can be used alone, or multiple shapes can be mixed. The periodicity of the shape is not particularly limited. The periodicity of the shape can be random or can be periodic.

[0320] In the present disclosure, preferably, at least a part of the peripheral portion of the photoelectric conversion layer includes a missing portion, and the sealing portion is provided between the missing portion and the second substrate.

[0321] Since fine uneven portions are formed by the missing portion, the adhesion to the sealing portion is improved by the anchoring effect, and the durability against mechanical stress can be improved while maintaining high durability against high temperature and high humidity.

[0322] The sealing member is not particularly limited and can be appropriately selected according to the intended purpose, as long as it inhibits the entry of water vapor in the air. Examples of the sealing member include low-melting-point sintered glass, ultraviolet curable resins such as epoxy resins and acrylic resins, and thermosetting resins. These can be used alone or in combination. In addition to the above-mentioned constituent materials, a desiccant can also be mixed to further inhibit the entry of water vapor.

[0323] In the present disclosure, an epoxy resin is preferably used as the sealing member.

[0324] When an epoxy resin is used as the sealing member and the hole transport layer contains at least one selected from the tertiary amine compounds represented by the general formula (1) and the tertiary amine compounds represented by the general formula (2), even when the photoelectric conversion element is stored under high-temperature and high-humidity conditions, the high output obtained before storage can be maintained.

[0325] In addition, since the flexibility of the cured product and the adhesion to the substrate can be well maintained, good mechanical durability can also be obtained.

[0326] The epoxy resin is not particularly limited and can be appropriately selected according to the intended purpose, as long as it is a resin obtained by curing a monomer or oligomer including an epoxy group in its molecule. Examples of the epoxy resin include water-dispersed epoxy resins, non-solvent epoxy resins, solid epoxy resins, thermosetting epoxy resins, epoxy resins mixed with curing agents, and ultraviolet curable epoxy resins. Among them, thermosetting epoxy resins and ultraviolet curable epoxy resins are preferred, and ultraviolet curable epoxy resins are more preferred. Note that the ultraviolet curable epoxy resin can be heated.

[0327] Examples of the epoxy resin include bisphenol A-based epoxy resins, bisphenol F-based epoxy resins, novolak-based epoxy resins, alicyclic epoxy resins, long-chain aliphatic epoxy resins, glycidylamine-based epoxy resins, glycidyl ether-based epoxy resins, and glycidyl ester-based epoxy resins. These can be used alone or in combination.

[0328] If necessary, the epoxy resin can include a curing agent and various additives.

[0329] Examples of the curing agent include amine-based curing agents, acid anhydride-based curing agents, polyamide-based curing agents, and other curing agents.

[0330] Examples of the amine-based curing agents include aliphatic polyamines such as diethylenetriamine and triethylenetetramine; and aromatic polyamines such as methylenedianiline, diaminodiphenylmethane, and diaminodiphenylsulfone.

[0331] Examples of the acid anhydride-based curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnaphthalic anhydride, pyromellitic dianhydride, HET anhydride, and dodecenyl succinic anhydride.

[0332] Examples of other curing agents include imidazole and polythiol. These can be used alone or in combination.

[0333] Examples of the additives include fillers, spacers, polymerization initiators, desiccants (moisture absorbers), curing accelerators, coupling agents, toughening agents, colorants, flame retardant aids, antioxidants, and organic solvents. These can be used alone or in combination. Among them, fillers, gap agents, curing accelerators, polymerization initiators, and desiccants (moisture absorbers) are preferred, and fillers and polymerization initiators are particularly preferred.

[0334] - Fillers -

[0335] Fillers are effective in preventing the entry of moisture or oxygen in the external environment. In addition, fillers can achieve effects such as reducing the volume shrinkage during curing, reducing the amount of gas generated during curing or heating, improving mechanical strength, and controlling thermal conductivity or fluidity, and are very effective in maintaining a stable output in various environments in the present disclosure.

[0336] Regarding the output characteristics or durability of the photoelectric conversion element, not only the influence of moisture or oxygen entering the photoelectric conversion element from the external environment cannot be ignored, but also the influence of the gas generated during heating and curing the sealing member cannot be ignored. In particular, the influence of the gas generated during heating greatly affects the output characteristics of the photoelectric conversion element when stored in a high-temperature environment.

[0337] In this case, when fillers, gap agents, and desiccants are included in the sealing member, they can prevent the entry of moisture or oxygen, and can reduce the amount of the sealing member used, thereby achieving the effect of reducing gas generation. This is effective not only during curing but also when the photoelectric conversion element is stored in a high-temperature environment.

[0338] The fillers are not particularly limited and known products can be used. Preferred examples of the fillers include inorganic fillers such as crystalline or amorphous silica, talc, alumina, aluminum nitride, silicon nitride, calcium silicate, and calcium carbonate. These can be used alone or in combination.

[0339] The average primary particle diameter of the filler is preferably 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less. An average primary particle diameter of the filler satisfying 0.1 μm or more and 10 μm or less is effective because the effect of preventing moisture or oxygen from entering can be sufficiently achieved, the viscosity becomes appropriate, the adhesion to the substrate or the defoaming property is improved, and the control of the width and processability of the sealing portion is achieved.

[0340] Preferably, the filler is uniformly provided in the sealing portion. This makes it possible to sufficiently obtain the effect of suppressing the entry of moisture or oxygen. When a gap filler or a spacer is used, a layer with a low filler density may be formed near its boundary. In this case, by extending the distance of the layer with a low filler density in the width direction of the sealing portion, the effect of suppressing the entry of moisture or oxygen can be sufficiently obtained. The density of the filler can be measured by, for example, a scanning electron microscope (SEM).

[0341] The amount of the filler is preferably 10 parts by mass or more and 90 parts by mass or less, more preferably 20 parts by mass or more and 70 parts by mass or less, relative to the total amount of the sealing member. When the amount of the filler is 10 parts by mass or more and 90 parts by mass or less, the effect of preventing moisture or oxygen from entering can be sufficiently obtained, the viscosity becomes appropriate, and the adhesion and processability are good.

[0342] - Gap filler -

[0343] The gap filler is also called a gap control agent or a spacer, and can control the gap of the sealing portion. For example, when a sealing member is provided on a first substrate or a first electrode and a second substrate is provided thereon for sealing, since the gap filler is mixed in the epoxy resin, the gap of the sealing portion matches the size of the gap filler. As a result, the gap of the sealing portion can be easily controlled.

[0344] As the gap filler, materials known in the art can be used as long as they have a particulate shape and a uniform particle diameter, and have high solvent resistance and high heat resistance. Those having a high affinity for epoxy resin and having a spherical particulate shape are preferred. Specific examples thereof include glass beads, silica particles, and organic resin particles. These can be used alone or in combination.

[0345] The particle diameter of the gap filler can be selected according to the gap of the sealing portion to be set. The particle diameter of the gap filler is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less.

[0346] As another method of controlling the gap of the sealing portion, a spacer can be provided.

[0347] The spacer can be set at any position as long as it is located in the peripheral portion of the photoelectric conversion layer. For example, the spacer can be set on, for example, the first substrate, the first electrode, the hole blocking layer, the missing layer, the second electrode, or the second substrate. The spacer can be set on the aforementioned combinations.

[0348] The spacer can be set outside the sealing portion or can be incorporated inside the sealing portion.

[0349] The material of the spacer is not particularly limited and can be appropriately selected according to the intended purpose as long as it inhibits the entry of water vapor in the air. Examples of the material include glass materials, metal materials, metal oxide materials, ultraviolet curable resins such as epoxy resins or acrylic resins, and thermosetting resins. These can be used alone or in combination.

[0350] -Polymerization initiator-

[0351] The polymerization initiator is a material added for the purpose of initiating polymerization using heat or light.

[0352] The thermal polymerization initiator is a compound that generates active species such as free radicals or cations by heating. Specific examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) and peroxides such as benzoyl peroxide (BPO). Examples of the thermal cationic polymerization initiator include benzenesulfonate esters and alkylsulfonium salts.

[0353] Meanwhile, as the photoinitiator, a photo cationic polymerization initiator is preferably used in the case of epoxy resin. When the photo cationic polymerization initiator is mixed with epoxy resin and irradiated with light, the photo cationic polymerization initiator decomposes to generate a strong acid, and the acid initiates the polymerization of the epoxy resin. Then, the curing reaction proceeds. This photo cationic polymerization initiator has the effects of low volume shrinkage during curing, no oxygen inhibition, and high storage stability.

[0354] Examples of the photo cationic polymerization initiator include aromatic diazonium salts, aromatic iodine salts, aromatic sulfonium salts, metallocene compounds, and silanol-aluminum complexes. In addition, a photoacid generator having a function of generating an acid by irradiation with light can also be used.

[0355] The photoacid generator is used as an acid that initiates cationic polymerization. Examples of the photoacid generator include salts, such as ionic sulfonium salt-based salts and ionic iodine salt-based salts, which contain a cationic part and an anionic part. These can be used alone or in combination.

[0356] The amount of the polymerization initiator is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 5 parts by mass or less, relative to the total amount of the sealing member. An amount of the polymerization initiator that satisfies 0.5 parts by mass or more and 10 parts by mass or less enables the curing to proceed appropriately, can reduce the remaining uncured product, and can prevent an excessive amount of gas generation, which is effective.

[0357] -Desiccant-

[0358] A desiccant is also referred to as a moisture absorbent and is a material having a function of physically or chemically adsorbing or absorbing moisture. It is effective to include a desiccant in the sealing member because the moisture resistance can be further improved and the influence of outgassing can be reduced in some cases.

[0359] The desiccant is preferably particulate. Examples of the desiccant include inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolites. These can be used alone or in combination. Among them, zeolite is preferred because zeolite absorbs a large amount of moisture.

[0360] -Curing accelerator-

[0361] A curing accelerator is also referred to as a curing catalyst and is used for the purpose of accelerating the curing rate. Curing accelerators are mainly used for thermosetting epoxy resins.

[0362] Examples of the curing accelerator include: tertiary amines or tertiary amine salts such as DBU (1,8-diazabicyclo(5,4,0)-undec-7-ene) and DBN (1,5-diazabicyclo(4,3,0)-non-5-ene); imidazole-based compounds such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole; and phosphines or salts such as triphenylphosphine and tetraphenyl ·tetraphenylborate, etc. These can be used alone or in combination.

[0363] -Coupling agent-

[0364] The coupling agent has the effect of improving the bonding force between molecules, and examples of the coupling agent include silane coupling agents. Specific examples thereof include: silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)-3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyltrimethoxysilane. These can be used alone or in combination.

[0365] As the sealing member, an epoxy resin composition commercially available as a sealing material, a sealing member material, or an adhesive is known and can be effectively used in the present disclosure. Among them, the epoxy resin composition has been developed and is commercially available for use in solar cells or organic EL elements, and can be particularly effectively used in the present disclosure.

[0366] Examples of commercially available products include product names: TB3118, TB3114, TB3124, and TB3125F (all of which are available from ThreeBond), World Rock 5910, World Rock 5920, and World Rock 8723 (all of which are available from Kyoritsu Chemical & Co., Ltd.), and WB90US(P) (available from MORESCO).

[0367] The epoxy resin compositions are disclosed in, for example, Japanese Patent No. 4918975, Japanese Patent No. 5812275, Japanese Patent No. 5835664, Japanese Patent No. 5930248, and Japanese Unexamined Patent Application Publication No. 2012-136614, and these epoxy resin compositions can also be used.

[0368] In the present disclosure, a sheet-shaped sealing material can also be effectively used.

[0369] The sheet-like sealing material is a sheet on which an epoxy resin layer is pre-formed. As the sheet, for example, glass or a film having high gas barrier properties can be used, and the sheet-like sealing material corresponds to the substrate in the present disclosure. When the sheet-like sealing material is pasted on the second electrode of a photoelectric conversion element or a photoelectric conversion module and then cured, a sealing member and a substrate can be formed at once. It is effective to provide a hollow portion in the photoelectric conversion element according to the formation pattern of the epoxy resin layer formed on the sheet.

[0370] Preferably, the hollow portion specifically contains oxygen. Containing oxygen can stably maintain the hole-transporting function of the hole transport layer for a long period of time and improve the durability of the photoelectric conversion element or the photoelectric conversion module. The effect can be achieved as long as the oxygen concentration in the hollow portion provided by sealing contains oxygen. The oxygen concentration is preferably 1.0 vol% or more and 21.0 vol% or less, more preferably 3.0 vol% or more and 15.0 vol% or less.

[0371] By performing the sealing in a glove box in which the oxygen concentration is set, the oxygen concentration in the hollow portion can be controlled. The oxygen concentration can be set by a method using a gas cylinder having a specific oxygen concentration or by a method using a nitrogen generator. The oxygen concentration in the glove box is measured using a commercially available oxygen concentration meter or oxygen monitor.

[0372] The oxygen concentration inside the hollow portion formed by sealing can be measured by, for example, atmospheric pressure ionization mass spectrometry (API-MS). Specifically, the photoelectric conversion element or the photoelectric conversion module is placed in a chamber filled with an inert gas, and the sealed portion is opened in the chamber. Then, quantitative analysis of the gas in the chamber is performed by API-MS, and all components in the gas contained in the hollow portion are quantified. The ratio of oxygen to the sum of all components can be calculated to determine the oxygen concentration.

[0373] The gas other than oxygen is preferably an inert gas. Examples of the inert gas include nitrogen and argon.

[0374] When performing the sealing, it is preferable to control the oxygen concentration and the dew point inside the glove box, and such control is effective for improving the output and durability.

[0375] The dew point is defined as the temperature at which condensation begins when a gas containing water vapor is cooled.

[0376] The dew point is preferably 0°C or lower, more preferably -20°C or lower. The lower limit is preferably -50°C or higher.

[0377] In addition, a passivation layer can be provided between the second electrode and the sealing member. The passivation layer is not particularly limited and can be appropriately selected according to the intended purpose. For example, alumina, silicon nitride, and silicon oxide are preferred.

[0378] The method for forming the sealing member is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include dispensing method, wire bar method, spin coating method, roll coating method, knife coating method, gravure coating method, letterpress printing, offset printing, intaglio printing, rubber plate printing, and screen printing.

[0379] <deletion part>

[0380] The deletion part is preferably provided on at least a part of the peripheral portion of the photoelectric conversion layer.

[0381] The deletion part in the present disclosure preferably includes a deletion layer.

[0382] The deletion layer can be formed on the first substrate, on the first electrode, on the hole blocking layer, or on a combination of the foregoing.

[0383] The deletion part preferably has uneven portions.

[0384] The maximum thickness of the deletion layer included in the deletion part is preferably 5 nm or more and 1,000 nm or less, more preferably 10 nm or more and 300 nm or less.

[0385] The minimum thickness is preferably 1 / 10 or less of the maximum thickness, more preferably 0 nm.

[0386] When the minimum thickness is 0 nm, the percentage of the area including the deletion layer in the deletion part is preferably 30% or more and 95% or less, more preferably 40% or more and 80% or less.

[0387] The shape of the convex portion can be a periodic structure or a random structure. The shape of the convex portion can be a structure in which particles are bonded.

[0388] The concave portion can be sufficiently filled with the sealing member.

[0389] The filling state can be confirmed by scanning electron microscope (SEM).

[0390] When the maximum thickness and the minimum thickness fall within the preferred ranges, the adhesion to the sealing part is improved by the anchoring effect of the fine uneven portions. In addition, the deletion layer functions as a filler at the boundary between the substrate and the sealing part to delay the entry of moisture. In addition, the durability against mechanical stress can be improved while maintaining high durability against high temperature and high humidity.

[0391] The missing layer preferably contains the same material as the hole blocking layer. When the missing layer contains the same material as the hole blocking layer, the missing layer and the hole blocking layer adhere firmly to each other. As a result, the durability against mechanical stress can be improved while maintaining high durability against high temperature and high humidity.

[0392] The missing layer preferably contains one or more constituent materials of the photoelectric conversion layer, and more preferably contains at least the same material as the material of the electron transport layer.

[0393] The missing layer preferably contains an oxide semiconductor, more preferably titanium oxide, zinc oxide, tin oxide, and niobium oxide, and particularly preferably titanium oxide. The missing layer may further contain a photosensitive compound and a hole transport layer. In order to prevent curing failure of the sealing member, the missing layer more preferably does not include a hole transport layer.

[0394] The missing layer is formed from the residue obtained when each layer is removed.

[0395] In addition to thickness measurement, the residue can also be confirmed by elemental analysis of the surface. Confirmation can be performed by detecting the elements constituting the electron transport layer or the hole transport layer using measurements such as energy-dispersive X-ray spectroscopy SEM-EDX.

[0396] The method for confirming the maximum thickness and the minimum thickness is not particularly limited. The maximum thickness and the minimum thickness can be confirmed by known means. The maximum thickness and the minimum thickness can be measured by, for example, a scanning electron microscope (SEM).

[0397] The method for forming a cross-section for confirming the thickness is not particularly limited and conventional existing means can be used. A cross-section can be formed by known means such as a diamond cutting saw, a diamond wire saw, ion milling, and focused ion beam processing (FIB).

[0398] The thickness of the missing layer is in nanometers. Therefore, when measuring the missing layer using, for example, a scanning electron microscope (SEM), the measurement is performed within the recognizable visual range. For example, Figure 27 the measurement conditions (acceleration voltage: 3 kV, aperture: 60 μm) described above are preferred. Here, regarding the minimum thickness of 0 nm, the place where the missing layer cannot be confirmed under the measurement conditions (acceleration voltage: 3 kV, aperture: 60 μm) described in Figure 27 is considered to be 0 mm.

[0399] A scanning electron microscope (SEM) can be used to evaluate the region including the missing layer in the missing portion. As Figure 27 presented, within a width of about 3.8 μm, the region including the missing part can be calculated by the following equation.

[0400] Width of the layer with missing part / Entire width = Area of the layer with missing part (%)

[0401] Even when no uneven portions are formed on the first substrate or the first electrode, fine uneven portions can be formed by the missing layer. For example, the bonding region with the sealing portion has a plurality of boundaries between the first substrate and the first electrode, the wettability of the sealing member changes, and adhesion differences may occur. At the same time, for example, when the missing layer covers the first substrate and the first electrode, the bonding region with the sealing portion becomes the same boundary through the missing layer, the wettability does not change, and the adhesion becomes uniform. Since the difference in adhesion affects the stress tolerance, the same boundary is more preferable.

[0402] The method for forming the missing layer is not particularly limited and can be carried out according to known methods. Examples of the method include sandblasting, water spraying, polishing, chemical etching, and laser processing. Among them, laser processing is preferable.

[0403] When using the laser processing method, the laser can be emitted from the side of the first electrode or from the side of the second electrode. However, the laser is preferably emitted from the side of the first electrode.

[0404] In addition, defocusing helps to reduce damage to the electrode. The defocusing is preferably from -1 mm to -10 mm.

[0405] Regarding the timing of the treatment, after forming the film of the hole transport layer, not only the electron transport layer but also the hole transport layer is preferably treated simultaneously.

[0406] The power of the laser is preferably 5.0 μJ or more and 9.5 μJ or less, more preferably 7.0 μJ to 9.0 μJ. When the power of the laser is 10 μJ or more, the photoelectric conversion characteristics may be reduced due to damage to the counter electrode.

[0407] The pitch of the laser is preferably 1 μm or more and 80 μm or less, more preferably 10 μm or more and 30 μm or less. Controlling the pitch can obtain periodic laser marks. The laser marks can be confirmed by, for example, a microscope.

[0408] When the pitch of the laser falls within the preferred range, the missing layer can be formed in a compact manner while preventing damage to the counter electrode, and the durability against mechanical stress can be improved while maintaining high durability against high temperature and high humidity.

[0409] <First substrate>

[0410] The shape, structure, and size of the first substrate are not particularly limited and can be appropriately selected according to the intended purpose.

[0411] The material of the first substrate is not particularly limited and can be appropriately selected according to the intended purpose as long as it has transparency and insulation properties. Examples of the material include substrates such as glass, plastic plates, plastic films, plastic sheets, ceramics, and inorganic transparent crystal substances. Among them, when performing a firing step to form an electron transport layer as described below, a substrate having heat resistance to the firing temperature is preferred. In addition, the first substrate is preferably a flexible substrate.

[0412] <Second substrate>

[0413] The second substrate is not particularly limited and known products can be used. Examples of the second substrate include substrates such as glass, transparent plastic plates, transparent plastic films, inorganic transparent crystal substances, plastic films, and ceramics. Concavo-convex portions can be formed at the joint portion between the second substrate and the sealing member to increase adhesiveness.

[0414] The method of forming the concavo-convex portions is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the forming method include sandblasting, water spraying, sandpaper, chemical etching, and laser processing.

[0415] As a means of increasing the adhesiveness between the second substrate and the sealing member, for example, organic substances on the surface can be removed, or hydrophilicity can be improved. The means for removing organic substances on the surface of the second substrate is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the means include UV ozone washing and oxygen plasma treatment.

[0416] <Hole blocking layer>

[0417] The photoelectric conversion element can include a hole blocking layer.

[0418] The hole blocking layer is preferably formed between the first electrode and the electron transport layer.

[0419] The hole blocking layer transports electrons generated in the photosensitive compound and transmitted to the electron transport layer to the first electrode, and also prevents contact with the hole transport layer. Therefore, the hole blocking layer does not easily allow holes to flow to the first electrode and can prevent a reduction in output due to the recombination of electrons and holes. Compared with a wet-type photoelectric conversion element using an electrolyte, the recombination rate of holes in the hole transport material of a solid photoelectric conversion element provided with a hole transport layer and electrons on the electrode surface is relatively fast. Therefore, the effect obtained by forming the hole blocking layer is quite large.

[0420] The material of the hole blocking layer is not particularly limited and can be appropriately selected according to the intended purpose as long as the material is transparent to visible light and has electron transport properties. Examples of the material include elemental semiconductors such as silicon and germanium; compound semiconductors such as chalcogenides of metals; and compounds having a perovskite structure.

[0421] Examples of metal chalcogenides include: oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium and lead; and tellurides of cadmium. Other examples of compound semiconductors include: phosphides of zinc, gallium, indium, and cadmium; gallium arsenide; copper indium selenide; and copper indium sulfide.

[0422] Examples of compounds having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate.

[0423] Among them, oxide semiconductors are preferred, titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide, and tin oxide are more preferred, and titanium oxide is still more preferred.

[0424] These can be used alone or in combination. These can be a single layer or a laminated layer. The crystal type of these semiconductors is not particularly limited and can be appropriately selected according to the intended purpose. The crystal type can be single crystal, polycrystal, or amorphous.

[0425] The method for forming the hole blocking layer is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include: wet film formation such as sol-gel method and hydrolysis method using titanium tetrachloride; and dry film formation such as sputtering. Among them, the sputtering method is preferred. When the method for forming the hole blocking layer is the sputtering method, the film density can be high enough and current loss can be prevented.

[0426] The average thickness of the hole blocking layer is not particularly limited and can be appropriately selected according to the intended purpose. The average thickness of the hole blocking layer is preferably 5 nm or more and 1 μm or less. In wet film formation, the average thickness of the hole blocking layer is more preferably 500 nm or more and 700 nm or less. In dry film formation, the average thickness of the hole blocking layer is more preferably 5 nm or more and 30 nm or less.

[0427] Embodiments of the photoelectric conversion element of the present disclosure will be described in detail with reference to the drawings.

[0428] In each drawing, the same components can be denoted by the same reference numerals, and redundant descriptions can be omitted. The number, position, shape, etc. of the following components are not limited to the embodiments of the present disclosure, and the preferred number, position, shape, etc. of the components can be used for the present disclosure.

[0429] <First Embodiment>

[0430] Figure 1 is a schematic diagram showing an example of the photoelectric conversion element of the first embodiment. In Figure 1In the photoelectric conversion element, a first electrode 2 is formed on a first substrate 1, and a hole blocking layer 3 is formed on the first electrode 2. An electron transport layer 4 is formed on the hole blocking layer 3, and a photosensitive compound 5 is adsorbed on the surface of the electron transport material constituting the electron transport layer 4. A hole transport layer 6 is formed above and inside the electron transport layer 4, and a second electrode 7 is formed on the hole transport layer 6. A second substrate 8 is disposed above the second electrode 7, and the second substrate 8 is fixed by a sealing member 9 between the second substrate 8 and the first electrode 2.

[0431] Note that each of the first electrode 2 and the second electrode 7 may include a path configured to allow current to pass through each electrode lead-out terminal (not shown).

[0432] Figure 2 is Figure 1 A schematic top view of the photoelectric conversion element according to the first embodiment. As Figure 2 shown, a sealing portion 9 is provided at a peripheral portion of the second electrode. The sealing portion 9 includes a minimum width A and a maximum width B, and includes a distance C between the second electrode and the sealing portion 9.

[0433] This configuration enables an improvement in the sealing effect of preventing excessive entry of moisture or oxygen and an improvement in the durability against mechanical stress such as torsion.

[0434] <Second Embodiment>

[0435] Figure 3 is a schematic diagram showing an example of the photoelectric conversion element according to the second embodiment. Except that the hole blocking layer 3 provided on the first electrode 2 has the same size as the first electrode 2, and the second substrate 8 is fixed by a sealing member 9 between the second substrate 8 and the hole blocking layer 3, Figure 3 the photoelectric conversion element has the same configuration as the photoelectric conversion element according to the first embodiment.

[0436] In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and repeated descriptions will be omitted.

[0437] <Third Embodiment>

[0438] Figure 4 is a schematic diagram showing an example of the photoelectric conversion element according to the third embodiment. Except that a missing portion 10 including a missing layer 11 is provided on the first electrode 2, and the second substrate 8 is fixed by a sealing member 9 between the second substrate 8 and the missing layer 11, Figure 4 the photoelectric conversion element has the same configuration as the photoelectric conversion element according to the first embodiment.

[0439] In the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0440] <Fourth Embodiment>

[0441] Figure 5 is a schematic view showing an example of a photoelectric conversion element according to the fourth embodiment. Except that the hole blocking layer 3 provided on the first electrode 2 has the same size as the first electrode 2, a missing portion 10 including a missing layer 11 is provided on the hole blocking layer 3, and the second substrate 8 is fixed by a sealing member 9 between the second substrate 8 and the missing layer 11, Figure 5 the photoelectric conversion element has the same configuration as the photoelectric conversion element of the first embodiment.

[0442] In the fourth embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0443] <Fifth Embodiment>

[0444] Figure 6 is a schematic view showing an example of a photoelectric conversion element according to the fifth embodiment. Except that the hole blocking layer 3 provided on the first electrode 2 has the same size as the first electrode 2, a missing portion 10 including a missing layer 11 is provided on the hole blocking layer 3, and the second substrate 8 is fixed by a sealing member 9 including a spacer 12 between the second substrate 8 and the missing layer 11, Figure 6 the photoelectric conversion element has the same configuration as the photoelectric conversion element of the first embodiment.

[0445] In the fifth embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0446] (Photoelectric Conversion Module)

[0447] The photoelectric conversion module of the present disclosure includes a photoelectric conversion element setting area in which a plurality of photoelectric conversion elements are arranged adjacent to each other. The plurality of photoelectric conversion elements at least include a first electrode, an electron transport layer containing a photosensitive compound, a hole transport layer, and a second electrode. The plurality of photoelectric conversion elements include a sealing portion provided at an edge of the photoelectric conversion element setting area and configured to shield the electron transport layer from the external environment of the photoelectric conversion element, and further include other layers if necessary. Each layer may be a single-layer structure or may be a laminated layer structure.

[0448] The photoelectric conversion module of the present disclosure can have such a configuration including a plurality of photoelectric conversion elements.

[0449] The structure of each layer of the photoelectric conversion module may have the same structure as that of the photoelectric conversion element.

[0450] Examples of the photoelectric conversion module include structures in which a plurality of photoelectric conversion elements are connected in series or in parallel.

[0451] The photoelectric conversion module may be in the form of a continuous layer, in which at least the hole transport layer extends between at least two adjacent photoelectric conversion elements.

[0452] The photoelectric conversion module may have a structure including a pair of substrates, a photoelectric conversion element setting area between the pair of substrates, and a sealing member sandwiched between the pair of substrates.

[0453] Hereinafter, an example of the photoelectric conversion module of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited thereto, and those not described in the embodiments of the present disclosure regarding the number, position, and shape of the following constituent components may be included within the scope of the present disclosure.

[0454] Figure 7 is a schematic diagram showing an example of the photoelectric conversion module of the present disclosure. Figure 7 An example of a cross-section of a part of a photoelectric conversion module including a plurality of photoelectric conversion elements connected in series is presented.

[0455] In Figure 7 , after forming the hole transport layer 6, the through-hole 13 is formed. Then, the second electrode 7 is formed thereon, thereby introducing the material of the second electrode inside the through-hole 13, which allows current to flow through the first electrode 2 of the adjacent cell. Note that each of the first electrode 2 and the second electrode 7 has a path further adjacent to the electrode of the cell or is configured to allow current to pass through the electrode lead-out terminal, which is not presented in Figure 7 .

[0456] The through-hole 13 may penetrate the first electrode 2 to reach the first substrate 1, or may not reach the first substrate 1 by stopping the process inside the first electrode 2.

[0457] In the case where the shape of the through-hole 13 is such a micropore that penetrates the first electrode 2 and reaches the first substrate 1, when the total opening area of the micropore is too large relative to the area of the through-hole 13, the cross-sectional area of the film of the first electrode 2 decreases, thereby increasing the resistance value, which may lead to a reduction in the photoelectric conversion efficiency. Therefore, the ratio of the total opening area of the micropore to the area of the through-hole 13 is preferably 5 / 100 or more and 60 / 100 or less.

[0458] The method for forming the through-hole 13 is not particularly limited and can be appropriately selected according to the intended purpose. Examples of the method include a sandblasting method, a water jet method, a polishing method, a chemical etching method, and a laser processing method. Among them, the laser processing method is preferred. This enables the formation of minute holes without using, for example, sand, etching, or a resist, and enables processing with good cleanliness and reproducibility. Further, when forming the through-hole 13, at least one of the hole blocking layer 3, the electron transport layer 4, the hole transport layer 6, and the second electrode 7 can be removed by impact peeling using the laser processing method. As a result, a mask does not need to be provided at the time of lamination, and the removal and formation of the above-described minute through-hole 13 can be easily performed at once.

[0459] (Electronic device)

[0460] The electronic device of the present disclosure includes the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure, and a device configured to be driven by electric power generated by photoelectric conversion through the photoelectric conversion element and / or the photoelectric conversion module, and further includes other devices if necessary.

[0461] (Power supply module)

[0462] The power supply module of the present disclosure includes the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure and a power supply IC, and further includes other devices if necessary.

[0463] Specific embodiments of an electronic device including the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure, and a device configured to be driven by electric power obtained by power generation through the photoelectric conversion element and / or the photoelectric conversion module will be described.

[0464] Figure 8 An example in which a mouse is used as the electronic device is presented.

[0465] As Figure 8 presented in, the photoelectric conversion element and / or the photoelectric conversion module, the power supply IC, and the power storage device are combined, and the supplied electric power is allowed to be transmitted to the power supply of the control circuit of the mouse. As a result, the power storage device is charged when the mouse is not in use, and the mouse can be driven by electric power, so that a mouse that does not require wiring or battery replacement can be obtained. Since a battery is not required, its weight can be reduced, which is effective.

[0466] Figure 9It is a schematic diagram showing a photoelectric conversion element installed in a mouse. The photoelectric conversion element, power supply IC, and power storage device are installed inside the mouse, but the upper part of the photoelectric conversion element is covered by a transparent housing so that the photoelectric conversion element receives light. In addition, the entire housing of the mouse can be formed of transparent resin. The arrangement of the photoelectric conversion element is not limited to the above. For example, the photoelectric conversion element can be arranged at a position where light can be irradiated even when the mouse is covered by a hand, and such an arrangement may be preferable.

[0467] Another embodiment of an electronic device including the photoelectric conversion element and / or photoelectric conversion module of the present disclosure, and a device configured to be driven by the electric power obtained from the power generation by the photoelectric conversion element and / or photoelectric conversion module will be described.

[0468] Figure 10 An example of using a keyboard used in a personal computer as an electronic device is presented.

[0469] As Figure 10 presented, the photoelectric conversion element, power supply IC, and power storage device are combined, and the supplied electric power is allowed to be transmitted to the power supply of the control circuit of the keyboard. As a result, the power storage device can be charged when the keyboard is not in use, and the keyboard can be driven by this electric power. Therefore, such a keyboard that does not require wiring or battery replacement can be obtained. Since no battery is required, its weight can be reduced, which is effective.

[0470] Figure 11 A schematic diagram showing a photoelectric conversion element installed in a keyboard is presented. The photoelectric conversion element, power supply IC, and power storage device are installed inside the keyboard, but the upper part of the photoelectric conversion element is covered by a transparent housing so that the photoelectric conversion element receives light. The entire housing of the keyboard can be made of transparent resin. The arrangement of the photoelectric conversion element is not limited to the above.

[0471] In the case of a small keyboard where the space for incorporating the photoelectric conversion element is small, as Figure 12 presented, small photoelectric conversion elements can be embedded in some keys, and such an arrangement is effective.

[0472] Another embodiment of an electronic device including the photoelectric conversion element and / or photoelectric conversion module of the present disclosure, and a device configured to be driven by the electric power obtained from the power generation by the photoelectric conversion element and / or photoelectric conversion module will be described.

[0473] Figure 13 An example where a sensor is used as an electronic device is presented.

[0474] As Figure 13As presented, a photoelectric conversion element, a power supply IC, and a power storage device are combined so that the supplied power passes through the power supply of the sensor circuit. As a result, a sensor module can be configured without being connected to an external power supply and without replacing the battery. The sensing targets are, for example, temperature and humidity, illuminance, human detection, CO2, acceleration, UV, noise, geomagnetism, and atmospheric pressure, and such an electronic device can be applied to various sensors, which is effective. As Figure 13 presented, the sensor module is configured to periodically sense the target to be measured and transmit the read data to a personal computer (PC) or a smartphone via wireless communication.

[0475] As the Internet of Things (IoT) society approaches, the use of sensors is expected to increase significantly. Replacing the batteries of numerous sensors one by one is both time-consuming and unrealistic. In addition, the fact that sensors are installed in positions where it is not easy to replace the batteries, such as on ceilings and walls, also makes the operability poor. In addition, supplying power by a photoelectric conversion element is also a significantly great advantage. In addition, the photoelectric conversion element of the present disclosure has the following advantages: high output can be obtained even with low-illuminance light, and high mounting freedom can be achieved due to the small dependence of the output on the light incident angle.

[0476] Next, another embodiment of an electronic device including the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure, and a device configured to be driven by the power generated by the photoelectric conversion element and / or the photoelectric conversion module will be described.

[0477] Figure 14 An example of using a turntable as an electronic device is presented.

[0478] As Figure 14 presented, a photoelectric conversion element, a power supply IC, and a power storage device are combined so that the supplied power passes through the power supply of the turntable control circuit. As a result, a turntable can be configured without being connected to an external power supply and without replacing the battery.

[0479] For example, a turntable is used in a display case for displaying products. The wiring of the power supply will reduce the appearance of the display, and it is time-consuming to remove the displayed products when replacing the battery. Using the photoelectric conversion element of the present disclosure is effective because the above problems can be solved.

[0480] <Usage>

[0481] As described above, electronic devices including the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure, devices configured to be driven by electric power obtained from power generation by the photoelectric conversion element and / or the photoelectric conversion module, and power supply modules have been described. However, the described embodiments are only a part of the applicable embodiments, and the uses of the photoelectric conversion element or the photoelectric conversion module of the present disclosure are not limited to the above uses.

[0482] The photoelectric conversion element and / or the photoelectric conversion module can be applied to, for example, a power supply device by combining it with, for example, a circuit board configured to control the generated current.

[0483] Examples of devices using the power supply device include electronic desktop calculators, watches, mobile phones, electronic notebooks, and electronic paper.

[0484] In addition, a power supply device including a photoelectric conversion element can be used as an auxiliary power source for extending the continuous operation time of rechargeable or dry battery-powered electronic equipment.

[0485] The photoelectric conversion element and the photoelectric conversion module of the present disclosure can be used as a self-sustaining power source, and the electric power generated by photoelectric conversion can be used to drive a device. Since the photoelectric conversion element and the photoelectric conversion module of the present disclosure can generate electric power by irradiation with light, it is not necessary to connect an electronic device to a power source or replace a battery. Therefore, an electronic device can be driven in a place without power facilities, the electronic device can be worn or carried, and the electronic device can be driven without replacing the battery even in a place where it is not easy to replace the battery. In addition, when using a dry battery, the electronic device becomes heavy due to the weight of the dry battery, or the electronic device becomes large due to the size of the dry battery. Therefore, problems may occur when installing the electronic device on a wall or ceiling or transporting the electronic device. Since the photoelectric conversion element and the photoelectric conversion module of the present disclosure are light and thin, they can be freely installed, worn, and carried, which is advantageous.

[0486] As described above, the photoelectric conversion element and the photoelectric conversion module of the present disclosure can be used as a self-sustaining power source and can be combined with various electronic devices. For example, the photoelectric conversion element and the photoelectric conversion module of the present disclosure can be used in combination with many electronic devices such as display devices (e.g., electronic desktop calculators, watches, mobile phones, electronic notebooks, and electronic paper, etc.), accessories of personal computers (e.g., mice and keyboards), various sensor devices (e.g., temperature and humidity sensors and human detection sensors), transmitters (e.g., beacons and global positioning systems (GPS)), auxiliary lights, and remote controls.

[0487] The photoelectric conversion elements and photoelectric conversion modules of the present disclosure are widely applied because they can particularly generate electricity using low-illuminance light and can generate electricity indoors and in darker shadows. In addition, the photoelectric conversion elements and photoelectric conversion modules are highly safe because there is no visible liquid leakage as in the case of dry batteries, nor is there any visible accidental swallowing as in the case of button batteries. In addition, the photoelectric conversion elements and photoelectric conversion modules can be used as auxiliary power sources to extend the continuous operation time of rechargeable or dry-battery-powered electronic equipment. As described above, when the photoelectric conversion elements and photoelectric conversion modules of the present disclosure are combined with devices configured to be driven by the electricity generated by photoelectric conversion through the photoelectric conversion elements and photoelectric conversion modules, electronic devices that are lightweight, easy to use, have a high degree of mounting freedom, do not require battery replacement, have excellent safety, and effectively reduce the environmental load can be obtained.

[0488] Figure 15 A basic configuration diagram of an electronic device obtained by combining the photoelectric conversion element and / or photoelectric conversion module of the present disclosure with a device configured to be driven by the electricity generated by the photoelectric conversion element and / or photoelectric conversion module is presented. When the photoelectric conversion element is irradiated with light, the electronic device can generate electricity and the electricity can be drawn out. The circuit of the device can be driven by the generated electricity.

[0489] Since the output of the photoelectric conversion element varies depending on the ambient illuminance, Figure 15 the presented electronic device may not be stably driven in some cases. In such a case, as Figure 16 presented, a power supply IC for the photoelectric conversion element can be incorporated between the photoelectric conversion element and the circuit of the device to supply a stable voltage to the circuit side, and such an arrangement is effective.

[0490] As long as light with sufficient illuminance is emitted, the photoelectric conversion element can generate electricity. However, when the illuminance for generating electricity is insufficient, the desired electricity cannot be obtained, which is a disadvantage of the photoelectric conversion element. In such a case, as Figure 17 presented, when a power storage device such as a capacitor is installed between the power supply IC and the device circuit, the excess electricity from the photoelectric conversion element can be stored in the power storage device. In addition, the electricity stored in the power storage device can be supplied to the device circuit, enabling stable operation even when the illuminance is too low or even when no light is applied to the photoelectric conversion element.

[0491] As described above, the electronic device obtained by combining the photoelectric conversion element and / or photoelectric conversion module of the present disclosure with the device circuit can be driven even in an environment without a power source, does not require battery replacement, and can be stably driven by combining with a power supply IC or a power storage device. Therefore, the advantages of the photoelectric conversion element can be fully utilized.

[0492] Meanwhile, the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure can also be used as a power module, and such use is effective. As Figure 18 presented, for example, when the photoelectric conversion element and / or the photoelectric conversion module of the present disclosure is connected to a power supply IC for the photoelectric conversion element, a DC power module capable of supplying the power generated by the photoelectric conversion of the photoelectric conversion element to the power supply IC at a predetermined voltage level can be formed.

[0493] In addition, as Figure 19 presented, when a power storage device is added to the power supply IC, the power generated by the photoelectric conversion element can be stored in the power storage device. Therefore, even when the illuminance is too low or even when no light is applied to the photoelectric conversion element, a power module that can supply power to it can be formed.

[0494] Figure 18 and Figure 19 the power module of the present disclosure presented in can be used as a power module without replacing the battery, just like the case of a primary battery known in the art.

[0495] [Embodiment]

[0496] Hereinafter, embodiments of the present disclosure will be described. However, the present disclosure should not be construed as being limited to these embodiments.

[0497] (Embodiment 1)

[0498] (Production of the photoelectric conversion element)

[0499] On a glass substrate as the first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO) are sequentially sputtered to form a film, thereby obtaining ITO-coated glass as the first electrode, which is an ITO conductive film. On the ITO-coated glass, a dense layer formed of titanium oxide is formed as a hole blocking layer by reactive sputtering with oxygen.

[0500] Next, titanium oxide (product name: P90, obtained from NIPPON AEROSIL CO., LTD.) (3 g), acetylacetone (0.2 g), and polyoxyethylene octylphenyl ether (obtained from Wako Pure Chemical Industries, Ltd.) (0.3 g) as a surfactant were subjected to bead milling treatment for 12 hours together with water (5.5 g) and ethanol (1.0 g) to prepare a titanium oxide dispersion. Polyethylene glycol (product name: polyethylene glycol 20,000, obtained from Wako Pure Chemical Industries, Ltd.) (1.2 g) was added to the prepared titanium oxide dispersion to prepare a paste. The prepared paste was coated on the hole blocking layer (average thickness: 1.5 μm), dried at 50°C, and baked in air at 500°C for 30 min to form a porous electron transport layer.

[0501] The glass substrate on which the electron transport layer was formed was immersed in an acetonitrile / tert-butanol (volume ratio 1:1) solution of a photosensitizing compound (product name: DN455, obtained from Chemicrea Inc.) (0.2 mM) represented by the following structural formula (A) and chenodeoxycholic acid (CDCA, obtained from Tokyo Chemical Industry Co., Ltd.) (0.4 mM). The obtained product was left in the dark for 1 hour to adsorb the photosensitive compound on the surface of the electron transport layer.

[0502] To a chlorobenzene solution (1 mL) of a hole transport material represented by D-7 (246.5 mg), lithium bis(trifluoromethanesulfonyl)imide (product name: LiTFSI, obtained from Tokyo Chemical Industry Co., Ltd.) (37.0 mg) as an additive and a basic compound represented by C-1 (37.5 mg) were added and dissolved to prepare a hole transport layer coating solution.

[0503] [Chemical formula 36]

[0504]

[0505] Here, Ph represents a phenyl group.

[0506] On the electron transport layer on which the photosensitive compound was adsorbed, a hole transport layer (average thickness: 600 nm) was formed by spin coating using the hole transport layer coating solution. At this time, the peripheral portion of the electron transport layer was protected with masking tape so that the hole transport layer would not adhere to it. After forming the hole transport layer, the masking tape was peeled off and removed.

[0507] Then, silver is deposited on the hole transport layer under vacuum, and a second electrode (average thickness: 100 nm) is formed to produce a photoelectric conversion element.

[0508] After forming the second electrode, an acrylic resin (ultraviolet curable type, product name: TB3035B, obtained from ThreeBond Holdings Co., Ltd.) is coated as a sealing member using a screen printing machine (obtained from Micro-tec Co., Ltd.). The structure in the width direction can be adjusted by the printing pattern design of a screen printing plate (obtained from SONOCOM).

[0509] Then, nitrogen is introduced into the glove box, and the resultant is transferred therein. A cover glass as a second substrate is placed on the sealing member and the sealing member is cured by ultraviolet irradiation. Then, the power generation area is sealed to produce the photoelectric conversion element of Example 1.

[0510] Figure 20 And Table 1-1 presents the sealing structure having a bent shape in the photoelectric conversion element obtained in Example 1.

[0511] (Examples 2 to 9)

[0512] Except that the printing pattern is changed such that the sealing portion will have a bent shape as Figure 21 presented; and the values of the minimum width A, maximum width B, and distance C of the sealing portion are changed to the values presented in Table 1-1, the photoelectric conversion elements of Examples 2 to 9 are produced in the same manner as in Example 1.

[0513] (Examples 10 to 18)

[0514] Except that the sealing portion is changed to an epoxy resin (ultraviolet curable type, product name: WorldRock No. 5910, obtained from Kyoritsu Chemical & Co., Ltd.); and the values of the minimum width A, maximum width B, and distance C of the sealing portion are changed to the values presented in Table 1-1, the photoelectric conversion elements of Examples 10 to 18 are produced in the same manner as in Example 2.

[0515] (Example 19)

[0516] Except that the printing pattern is changed such that the sealing portion has a rectangular shape as Figure 22 presented; and the values of the minimum width A, maximum width B, and distance C of the sealing portion are changed to the values presented in Table 1-1, the photoelectric conversion element of Example 19 is produced in the same manner as in Example 12.

[0517] (Example 20)

[0518] Except for changing the printed pattern so that the sealing portion will have a wedge shape as presented in Figure 23 ; and changing the values of the minimum width A, the maximum width B, and the distance C of the sealing portion to the values presented in Table 1-1, the photovoltaic conversion element of Example 20 was produced in the same manner as in Example 12.

[0519] (Example 21)

[0520] Except for coating the electron transport layer and the hole transport layer over the entire substrate; simultaneously using a laser to perform impact peeling on the electron transport layer and the hole transport layer to form a missing portion; and coating a sealing member, the photovoltaic conversion element of Example 21 was produced in the same manner as in Example 12.

[0521] The laser was emitted from one side of the first electrode. The laser device was a laser patterning device (obtained from Seishin Trading Co., Ltd.). The oscillator was a THG (third harmonic generation) oscillator. The power was set to 8.5 microjoules, the defocus was set to -5 mm, the processing pitch was set to 20 micrometers, and the wavelength was set to 355 nm.

[0522] The thickness of the missing layer and the elemental analysis of the surface were measured in the following manner. Specifically, a cross-section was cut using a diamond wire saw (obtained from Meiwafosis Co., Ltd., DWS3100). The cross-section was processed under a focused ion beam scanning electron microscope FIB-SEM (obtained from Hitachi High-Technologies Corporation), and measurements were performed by energy dispersive X-ray spectroscopy SEM-EDX (obtained from Hitachi High-Technologies Corporation). The obtained SEM images and the measurement conditions of the SEM (acceleration voltage: 3 kV, aperture: 60 μm) are presented in Figure 27 ; the maximum thickness and the minimum thickness of the obtained missing layer and the area (%) of the region containing the missing layer are as presented in Table 1-1. In the elemental analysis of the surface, the element (Ti) derived from the electron transport layer was confirmed.

[0523] (Examples 22 to 32)

[0524] Except for adjusting the power, defocus, and processing pitch of the laser, and changing the maximum thickness and the minimum thickness of the missing layer and the area of the region containing the missing layer to those described in Table 1-1 and Table 1-2, the photovoltaic conversion elements of Examples 22 to 32 were produced in the same manner as in Example 21.

[0525] (Example 33)

[0526] The photovoltaic conversion element of Example 33 was produced in the same manner as in Example 12, except that the hole transport layer was formed without using a masking tape for protection; the hole transport layer around the peripheral portion of the electron transport layer was impacted and peeled off using a laser to form a missing portion; and a sealing member was coated.

[0527] The laser was emitted from the side of the first electrode. The laser device was a laser patterning device (obtained from Seishin Trading Co., Ltd.). The oscillator was a THG (third harmonic generation) oscillator. The power was set to 8.5 microjoules, the defocus was set to -5 mm, the processing pitch was set to 20 micrometers, and the wavelength was set to 355 nm.

[0528] The thickness of the missing layer and the elemental analysis of the surface were measured in the following manner. Specifically, a cross-section was cut using a diamond wire saw (obtained from Meiwafosis Co., Ltd., DWS3100). The cross-section was processed under a focused ion beam scanning electron microscope FIB-SEM (obtained from Hitachi High-Technologies Corporation), and measurement was performed by energy dispersive X-ray spectroscopy SEM-EDX (obtained from Hitachi High-Technologies Corporation). The maximum thickness and minimum thickness of the obtained missing layer and the area (%) including the missing layer are presented in Table 1-2. In the elemental analysis of the surface, elements (F, S) derived from the hole transport layer were confirmed.

[0529] (Examples 34 and 35)

[0530] The photovoltaic conversion elements of Examples 34 and 35 were produced in the same manner as in Example 21, except that the printing pattern was changed such that the distance C between the sealing portion and the second electrode would be 50 μm and 100 μm, respectively.

[0531] (Example 36)

[0532] The photovoltaic conversion element of Example 36 was produced in the same manner as in Example 35, except that SiO2 particles with a particle size of 40 μm as a spacer were mixed in the sealing member.

[0533] (Example 37)

[0534] The photovoltaic conversion element of Example 37 was produced in the same manner as in Example 35, except that the sealing member was coated without placing a cover glass thereon and was cured with ultraviolet rays (UV) to produce a spacer with a thickness of 40 micrometers, the sealing resin was coated again, and a cover glass was placed thereon for sealing.

[0535] (Example 38)

[0536] Except for using a laser device to laser-etch the ITO conductive film serving as the first electrode to process it into a 6-hole system substrate; after forming the hole transport layer, forming through-holes configured to serially connect photovoltaic conversion elements by laser processing; and depositing silver on the hole transport layer in a vacuum using a mask patterned to have a 6-hole system to form a second electrode (average thickness: 100 nm), the photovoltaic conversion module of Example 38 was produced in the same manner as in Example 37.

[0537] (Comparative Example 1)

[0538] Except for changing the printing pattern such that the sealing portions having the same width are arranged in a linear manner as presented in Figure 24 ; and changing the values of the minimum width A, the maximum width B, and the distance C to the values presented in Table 1-2, the photovoltaic conversion element of Comparative Example 1 was produced in the same manner as in Example 1.

[0539] (Comparative Example 2)

[0540] Except for changing the printing pattern such that the sealing portions having the same width are arranged in a curved manner as presented in Figure 25 ; and changing the values of the minimum width A, the maximum width B, and the distance C to the values presented in Table 1-2, the photovoltaic conversion element of Comparative Example 2 was produced in the same manner as in Example 1.

[0541] (Comparative Examples 3 and 4)

[0542] Except for changing the printing pattern such that the values of the minimum width A, the maximum width B, and the distance C of the sealing portion are changed to the values presented in Table 1-2, respectively, the photovoltaic conversion elements of Comparative Examples 3 and 4 were produced in the same manner as in Example 1.

[0543] The initial maximum output power (Pmax1) and the durability maintenance rate (Pmax2 / Pmax1) of the obtained photovoltaic conversion elements of Examples 1 to 38 and Comparative Examples 1 to 4 were measured in the following manner. The results are presented in Tables 1-1 and 1-2.

[0544] <Initial maximum output power (Pmax1) and durability maintenance rate (Pmax2 / Pmax1)>

[0545] Under the irradiation of a white LED adjusted to 200 lux, the IV characteristics of each of the produced photovoltaic conversion elements were evaluated using a solar cell evaluation system (DC voltage·current source / monitor, 6241A, obtained from ADC CORPORATION) to determine the initial maximum output power Pmax1 (μW / cm 2 ).

[0546] Then, support three corners of each of the produced photoelectric conversion elements, and perform a torsion test on one corner, where a load of 15 N is applied to one corner. The torsion test is performed at each of the four corners.

[0547] In addition, after the torsion test, the photoelectric conversion element is stored for 500 hours in an environment (40 °C, 90% RH) under irradiation of a white LED adjusted to 200 lux. Then, the IV characteristics of the photoelectric conversion element are evaluated again to determine the maximum output power Pmax2 (μW / cm 2 ) after the high-temperature and high-humidity use test. Divide the obtained Pmax2 by Pmax1 as the initial value to determine the "durability retention rate" (Pmax2 / Pmax1).

[0548] [Table 1-1]

[0549]

[0550] [Table 1-2]

[0551]

[0552] From the results of Table 1-1 and Table 1-2, it can be seen that the photoelectric conversion elements of Examples 1 to 38 that satisfy "the width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less" are excellent in durability against mechanical stress and stability over time in the torsion test.

[0553] Specifically, it is believed that since the sealing portion is provided around the photoelectric conversion layer, when the photoelectric conversion element is deformed due to mechanical stress, damage (peeling and cracking) of the photoelectric conversion layer can be prevented; and the displacement amount can become larger according to the deformation of the photoelectric conversion element to prevent peeling or breakage of the sealing portion.

[0554] Meanwhile, the photoelectric conversion elements of Comparative Examples 1 to 4 that do not satisfy "the width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less" cannot obtain the desired characteristics.

[0555] From the above results, it can be seen that the photoelectric conversion element of the present disclosure is excellent in durability against mechanical stress and stability over time.

[0556] For example, aspects of the present disclosure are as follows.

[0557] <1>A photoelectric conversion element, comprising:

[0558] The first substrate;

[0559] The first electrode;

[0560] The photoelectric conversion layer;

[0561] The second electrode; and

[0562] The second substrate,

[0563] wherein the photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer,

[0564] the sealing portion is provided so as to surround the periphery of the photoelectric conversion layer, and

[0565] the width of the sealing portion provided on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less.

[0566] <2>The photoelectric conversion element according to <1>,

[0567] wherein at least a part of the peripheral portion of the photoelectric conversion layer includes a missing portion,

[0568] the photoelectric conversion element includes a sealing portion between the missing portion and the second substrate, and

[0569] the missing portion includes a missing layer containing one or more constituent materials of the photoelectric conversion layer.

[0570] <3>The photoelectric conversion element according to <2>,

[0571] wherein the missing layer has concavo-convex portions.

[0572] <4>The photoelectric conversion element according to <3>,

[0573] wherein the maximum thickness of the missing layer is 10 nm or more and 300 nm or less.

[0574] <5>The photoelectric conversion element according to <3> or <4>,

[0575] wherein the minimum thickness of the missing layer is 0 nm.

[0576] <6>The photoelectric conversion element according to any one of <2> to <5>,

[0577] wherein the photoelectric conversion layer includes an electron transport layer and a hole transport layer, and

[0578] the missing layer includes the same material as the electron transport layer.

[0579] <7>The photoelectric conversion element according to any one of <1> to <6>,

[0580] wherein a ratio (B / A) of the maximum width B to the minimum width A is 1.09 or more and 3.0 or less.

[0581] <8>The photoelectric conversion element according to any one of <1> to <7>,

[0582] wherein a distance C between the sealing portion and the second electrode is 30 micrometers or more.

[0583] <9>The photoelectric conversion element according to any one of <1> to <8>,

[0584] wherein the sealing portion includes an epoxy resin.

[0585] <10>The photoelectric conversion element according to any one of <1> to <9>,

[0586] wherein the sealing portion is formed of a sealing resin and a spacer.

[0587] <11>A photoelectric conversion module, comprising

[0588] a plurality of photoelectric conversion elements, each of the plurality of photoelectric conversion elements being the photoelectric conversion element according to any one of <1> to <10>.

[0589] <12>The photoelectric conversion module according to <11>,

[0590] wherein the plurality of photoelectric conversion elements are connected in series or in parallel.

[0591] <13>An electronic device, comprising:

[0592] the photoelectric conversion element according to any one of <1> to <10> or the photoelectric conversion module according to <11> or <12>; and

[0593] a device configured to be driven by electric power generated by photoelectric conversion through the photoelectric conversion element or the photoelectric conversion module.

[0594] <14>A power supply module, comprising:

[0595] the photoelectric conversion element according to any one of <1> to <10> or the photoelectric conversion module according to <11> or <12>; and

[0596] a power supply IC.

[0597] <15>An electronic device, comprising:

[0598] The power supply module according to <14>; and

[0599] An electricity storage device.

[0600] The photoelectric conversion element according to any one of <1> to <10>, the photoelectric conversion module according to <11> or <12>, the electronic device according to <13> or <15>, and the power supply module according to <14> can solve the problems existing in the prior art and can achieve the object of the present disclosure.

[0601] [List of reference numerals]

[0602] 1: First substrate

[0603] 2: First electrode

[0604] 3: Hole blocking layer

[0605] 4: Electron transport layer

[0606] 5: Photosensitive compound

[0607] 6: Hole transport layer

[0608] 7: Second electrode

[0609] 8: Second substrate

[0610] 9: Sealing portion

[0611] 10: Missing portion

[0612] 11: Missing layer

[0613] 12: Spacer

Claims

1. A photoelectric conversion element, comprising: A first substrate; A first electrode; A photoelectric conversion layer; A second electrode; And A second substrate, Wherein the photoelectric conversion element includes at least a sealing portion that seals the photoelectric conversion layer, The sealing portion is arranged to surround the periphery of the photoelectric conversion layer, and The width of the sealing portion on each side has a minimum width A and a maximum width B in the width direction, and the ratio (B / A) of the maximum width B to the minimum width A is 1.02 or more and 5.0 or less, wherein The photoelectric conversion layer has a missing portion at least in a part of the periphery, The sealing portion is located between the missing portion and the second substrate, The missing portion has a missing layer, The photoelectric conversion layer has an electron transport layer and a hole transport layer, and The missing layer and the electron transport layer contain an oxide semiconductor.

2. The photoelectric conversion element according to claim 1, Wherein the missing layer contains one or more constituent materials of the photoelectric conversion layer.

3. The photoelectric conversion element according to claim 2, Wherein the missing layer has uneven portions.

4. The photoelectric conversion element according to claim 3, Wherein the maximum thickness of the missing layer is 10 nm or more and 300 nm or less.

5. The photoelectric conversion element according to claim 3 or 4, Wherein the minimum thickness of the missing layer is 0 nm.

6. The photoelectric conversion element according to claim 1, Wherein the missing layer includes the same material as the electron transport layer.

7. The photoelectric conversion element according to claim 1, Wherein the ratio (B / A) of the maximum width B to the minimum width A is 1.09 or more and 3.0 or less.

8. The photoelectric conversion element according to claim 1, Wherein the distance C between the sealing portion and the second electrode is 30 micrometers or more.

9. The photoelectric conversion element according to claim 1, Wherein the sealing portion includes an epoxy resin.

10. The photoelectric conversion element according to claim 1, Wherein the sealing portion is formed by a sealing resin and a spacer.

11. A photoelectric conversion module, comprising A plurality of photoelectric conversion elements, each of the plurality of photoelectric conversion elements being the photoelectric conversion element according to any one of claims 1 to 10.

12. The photoelectric conversion module according to claim 11, Wherein the plurality of photoelectric conversion elements are connected in series or in parallel.

13. An electronic device, comprising: The photoelectric conversion element according to any one of claims 1 to 10 or the photoelectric conversion module according to claim 11 or 12; And A device configured to be driven by electric power generated by photoelectric conversion through the photoelectric conversion element or the photoelectric conversion module.

14. A power supply module, comprising: The photoelectric conversion element according to any one of claims 1 to 10 or the photoelectric conversion module according to claim 11 or 12; And A power supply IC.

15. An electronic device, comprising: The power supply module according to claim 14; And A power storage device.

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