Composition and photoelectric conversion element

Abstract

The present invention provides a composition usable in photoelectric conversion elements that can achieve both excellent photoelectric conversion characteristics and excellent photodurability. [Solution] The solution comprises at least one selected from the group consisting of a compound represented by the following chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound comprises multiple types of compounds with different values ​​of Z. TIFF2026116031000055.tif44147 Ar is a structure containing an aromatic ring, -LZ may be one or more, and if there are multiple, each L and each Z may be the same or different from each other, each L is an atomic group that bonds Ar and Z or is covalently bonded, and each Z is a group that can form a chemical bond or hydrogen bond with a metal oxide.

Description

Technical Field

[0001] The present disclosure relates to a composition and a photoelectric conversion device.

Background Art

[0002] In recent years, photovoltaic power generation as a clean energy has attracted attention, and the development of solar cells has advanced. As one of them, a solar cell using a perovskite material as a light absorption layer has rapidly attracted attention as a next-generation solar cell that can be manufactured at low cost. For example, in Non-Patent Document 1, a solution-type solar cell using a perovskite material as a light absorption layer has been reported. In addition, Non-Patent Document 2 also reports that a solid-type perovskite solar cell exhibits high efficiency.

[0003] As an example of the basic structure of a perovskite solar cell, there is a normal structure in which an electron transport layer, a light absorption layer (perovskite layer), a hole transport layer (also referred to as a hole transport layer), and a back electrode are laminated in this order on an electrode. As another example, there is an inverted structure in which a hole transport layer, a light absorption layer, an electron transport layer, and a back electrode are laminated in this order on an electrode. In addition, a porous electron transport layer may be disposed between the electron transport layer and the perovskite layer. Among these, as a material for forming the hole transport layer, for example, there is a carbazole-type hole transport material having phosphonic acid (Non-Patent Document 3). This compound reacts with an indium tin compound (ITO) used as a transparent electrode and forms a monomolecular layer on the transparent electrode. Furthermore, Patent Document 1 describes mixing two types of carbazole-type hole transport materials.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-46212 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, conventional perovskite solar cells do not have sufficient photoelectric conversion efficiency. To improve the photoelectric conversion efficiency of solar cells, it is particularly important to improve the properties of the hole transport layer. For this purpose, carbazole-type hole transport materials containing phosphonic acid have been reported in recent years. This compound reacts with indium tin compounds (ITO), which are used as transparent electrodes, to form a monolayer on the transparent electrode. The hole transport compound that forms this monolayer has been reported to have a photoelectric conversion efficiency of over 20%, making it a very excellent compound. However, if the coverage of the hole transport layer on the electrode is insufficient, the electrode and the photoelectric conversion layer may come into contact, which may reduce the photoelectric conversion characteristics and may result in insufficient photodurability.

[0007] Therefore, the present disclosure aims to provide a composition usable in photoelectric conversion elements that can achieve both excellent photoelectric conversion characteristics and excellent photodurability, and a photoelectric conversion element using the same. [Means for solving the problem]

[0008] To achieve the above objective, the compositions of the present disclosure include at least one selected from the group consisting of a compound represented by the following chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound is characterized in that it includes multiple types of compounds in which Z in the following chemical formula (I) is different from each other.

[0009] [ka]

[0010] In the above chemical formula (I), Ar has a structure that includes an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms. Ar may or may not have substituents other than -LZ. -LZ may be one or more, and if there are multiple, each L and each Z may be the same or different from one another. Each L is either an atomic group bonding Ar and Z, or a covalent bond. Each Z is a group that can form chemical bonds or hydrogen bonds with a metal oxide.

[0011] The photoelectric conversion element of the present disclosure is characterized in that a first electrode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a second electrode are stacked in the order described above, the photoelectric conversion layer includes a perovskite structure, and the hole transport layer includes the composition of the present disclosure. [Effects of the Invention]

[0012] According to this disclosure, it is possible to provide a composition that can be used in a photoelectric conversion element that can achieve both excellent photoelectric conversion characteristics and excellent photodurability, and a photoelectric conversion element using the same. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a cross-sectional view showing an example of a photoelectric conversion element according to the present disclosure. [Modes for carrying out the invention]

[0014] This disclosure will be explained in more detail with examples. However, this disclosure is not limited to the following explanation. In the following explanation, the case in which the photoelectric conversion element of this disclosure is a solar cell will be explained in particular.

[0015] [1. Composition] As described above, the compositions of this disclosure include at least one selected from the group consisting of a compound represented by the following chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound is characterized in that it includes multiple types of compounds in which Z in the following chemical formula (I) is different from each other.

[0016] [ka]

[0017] In the above chemical formula (I), Ar has a structure that includes an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms. Ar may or may not have substituents other than -LZ. -LZ may be one or more, and if there are multiple, each L and each Z may be the same or different from one another. Each L is either an atomic group bonding Ar and Z, or a covalent bond. Each Z is a group that can form chemical bonds or hydrogen bonds with a metal oxide.

[0018] In the compositions of this disclosure, the compound represented by chemical formula (I) may, for example, have Ar represented by the following chemical formula (I-1) in chemical formula (I).

[0019] [ka]

[0020] In the above chemical formula (I-1), Ar 11 This is an atomic group containing a cyclic structure, and the cyclic structure may be an aromatic ring or an unaromatic ring, a monoring, a fused ring or a spiroring, and may or may not contain heteroatoms among the atoms constituting the ring. Ar 12is an aromatic ring, which may or may not contain a heteroatom among the atoms constituting the ring. Ar 12 is one or more atoms that share with Ar 11 and may be integrated with Ar 11 to form an integrated structure. Ar 12 can be one or more. When there are multiple, they may be the same as or different from each other. Ar 12 The number of is not particularly limited, but for example, it may be in the range of 1 to 4.

[0021] The composition of the present disclosure, for example, in the above chemical formula (I - 1), the Ar 11 may be represented by any one of the following chemical formulas (a1) to (a10).

[0022]

Chemical formula

[0023] The composition of the present disclosure, for example, in the above chemical formula (I - 1), each of the Ar 12 may be represented by the following chemical formula (b) respectively.

[0024]

Chemical formula

[0025] In the above chemical formula (b), The carbon atoms C 1 and C 2 also serve as part of the atoms constituting the cyclic structure in the Ar 11 in the above chemical formula (I - 1). The R 1 is a hydrogen atom, X in the above chemical formula (I) 1 , or a substituent. The substituent may or may not contain a hydrogen atom, and at least one of the hydrogen atoms in the substituent may be substituted by X in the above chemical formula (I) 1 . Each of the R 11These may be the same or different from each other, and each may be a hydrogen atom or a substituent, or two adjacent R atoms. 11 These may form a fused ring together with the benzene ring to which they are bonded. Each of the above R 11 It may or may not have substituents.

[0026] The compositions of this disclosure may, for example, have chemical formula (b) represented by any of the following chemical formulas (b1) to (b7).

[0027] [ka] In the above chemical formulas (b1) to (b7), C 1 , C 2 and R 1 These are the same as chemical formula (b) above.

[0028] In the above chemical formula (I), L may be, for example, a divalent linking group or a single bond that connects Ar and Z. In chemical formula (I), L, which is a divalent linking group, may be, for example, an alkylene group (which may be linear or branched, and the number of carbon atoms is not particularly limited but is preferably 1 to 8), a vinylene group, a vinylidene group, an ethynylene group, an aromatic ring group (for example, a divalent aromatic ring group derived from the aromatic ring exemplified by Ar in chemical formula (I)), a non-aromatic ring group (which may be monocyclic or polycyclic, and may have heteroatoms, for example, a piperazine ring group), -O-, -S-, -NR N -(R N Examples include a hydrogen atom or an alkyl group, wherein the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited but 1 to 8 is preferred), and a divalent linking group consisting of a combination of two or more (for example, 2 to 6) of these. The above combination of two or more divalent linking groups may be a combination of different groups or a combination of the same groups.

[0029] In the L in the chemical formula (I), the divalent linking group may or may not have one or more substituents (e.g., 1 to 6) if possible. The substituents are not particularly limited, but may be similar to the groups derived from the structure exemplified as Ar, or similar to the groups exemplified as Z later.

[0030] As described above, Z in chemical formula (I) is a group that can form a chemical bond or hydrogen bond with a metal oxide, and if there are multiple Zs, each Z may be the same or different from the others. Z is not particularly limited, but for example, each may independently be a dihydroxyphosphoryl group (-P=O(OH)2), a carboxyl group (-COOH), a sulfo group (-SO3H), a boronic acid group (-B(OH)2), a trihalogenated silyl group (-SiX3, where X is a halo group), a trialkoxysilyl group (-Si(OQ)3, where Q is an alkyl group), a trihydroxysilyl group, or a dialkylphosphoryl group. The dihydroxyphosphoryl group (-P=O(OH)2) and the carboxyl group (-COOH) may form a salt with a cation. Examples of the cation include alkali metal cations such as potassium cations and sodium cations, ammonium cations, methylammonium cations, tetramethylammonium cations, and quaternary ammonium cations such as tetra-n-butylammonium cations.

[0031] Specific examples of the compound represented by the chemical formula (I) include compounds with a structure represented by any of the following chemical formulas (A-1) to (A-15). In the following chemical formulas (A-1) to (A-15), L and Z are the same as in the chemical formula (I), R represents a substituent, and R may be zero (i.e., not present), one or more, and if there are multiple Rs, they may be the same or different from each other.

[0032] [ka]

[0033] [ka]

[0034] The substituent R in the chemical formulas (A1) to (A15) is not particularly limited, but examples include alkyl groups such as methyl, ethyl, and isopropyl groups; alkoxy groups such as methoxy and ethoxy groups; aryl groups such as phenyl and 1-naphthyl groups; heterocyclic groups such as thienyl and furyl groups; and halogen atoms such as fluorine, chlorine, and bromine. The substituent R may or may not be substituted with further substituents.

[0035] In the present invention, chain-like groups or atomic groups (e.g., hydrocarbon groups such as alkyl groups and unsaturated aliphatic hydrocarbon groups) may be linear or branched unless otherwise specified, and the number of carbon atoms is not particularly limited, but may be, for example, 1-40, 1-32, 1-24, 1-18, 1-12, 1-6, or 1-2 (2 or more in the case of unsaturated hydrocarbon groups). Also in the present invention, the number of ring members (number of atoms constituting the ring) of cyclic groups or atomic groups (e.g., aromatic rings, aromatic groups, etc., such as aryl groups and heteroaryl groups) is not particularly limited, but may be, for example, 5-32, 5-24, 6-18, 6-12, or 6-10. Furthermore, if isomers exist for substituents, etc., any isomer may be used unless otherwise specified, for example, when simply referred to as "naphthyl group", it may be either a 1-naphthyl group or a 2-naphthyl group.

[0036] In the present invention, the term "substituent" is not particularly limited, but examples include alkyl groups, unsaturated aliphatic hydrocarbon groups, alkoxy groups, aralkyl groups, aryl groups, heteroaryl groups, halogens, hydroxyl groups (-OH), mercapto groups (-SH), alkylthio groups (-SR, where R is an alkyl group), sulfo groups, nitro groups, diazo groups, cyano groups, trifluoromethyl groups, and the like.

[0037] In this disclosure, if a compound has isomers such as tautomers or stereoisomers (e.g., geometric isomers, conformational isomers, and optical isomers), any isomer may be used unless otherwise specified. Also in this disclosure, if a compound can form a salt, the salt may be used unless otherwise specified. The salt may be an acid addition salt or a base addition salt. Furthermore, the acid forming the acid addition salt may be an inorganic acid or an organic acid, and the base forming the base addition salt may be an inorganic base or an organic base. The inorganic acid is not particularly limited and includes, for example, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypofluorite, hypochlorous acid, hypobromous acid, hypoiodic acid, hypofluorite, chlorous acid, bromous acid, iodic acid, fluorite, chlorite, bromic acid, iodic acid, perfluorite, perchlorite, perbromic acid, and periodic acid. The organic acid is not particularly limited and includes, for example, p-toluenesulfonic acid, methanesulfonic acid, oxalic acid, p-bromobenzenesulfonic acid, carbonic acid, succinic acid, citric acid, benzoic acid, and acetic acid. The inorganic base is not particularly limited and includes, for example, ammonium hydroxide, alkali metal hydroxide, alkaline earth metal hydroxide, carbonate, and bicarbonate. More specifically, it includes, for example, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, calcium hydroxide, and calcium carbonate. The organic base is also not particularly limited and includes, for example, ethanolamine, triethylamine, and tris(hydroxymethyl)aminomethane. The method for producing these salts is also not particularly limited and can be produced, for example, by appropriately adding the above-mentioned acids and bases to the compound by known methods.

[0038] As described above, the compositions of the present disclosure include at least one selected from the group consisting of a compound represented by the chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound includes a plurality of types of compounds in which Z in the following chemical formula (I) is different from each other. In the plurality of types of compounds, it is preferable that at least one of the compounds is a compound in which Z in the chemical formula (I) is a phosphonic acid group or a salt thereof. The phosphonic acid group may be, for example, at least one of a phosphoryl group and a phosphate group. The content of compounds in which Z in the chemical formula (I) is different from Z in the chemical formula (I) is not particularly limited, but is preferably 1 to 10,000 parts by mass, and more preferably 10 to 1,000 parts by mass, per 100 parts by mass of the compound in which Z in the chemical formula (I) is a phosphonic acid group or a salt thereof.

[0039] In the compositions of the present disclosure, the plurality of compounds in which Z in chemical formula (I) differs from each other may include, for example, a first compound in which Z in chemical formula (I) is a phosphonic acid group and a second compound in which Z in chemical formula (I) is a carboxyl group. The content of the second compound is not particularly limited, but is preferably 1 to 10,000 parts by mass, and more preferably 10 to 1,000 parts by mass, with respect to 100 parts by mass of the first compound.

[0040] In the compositions of the present disclosure, the plurality of compounds in which Z in chemical formula (I) is different from each other may include, for example, at least one of the compound represented by the following chemical formula (II) and the compound represented by the following chemical formula (III).

[0041] [ka]

[0042] In the above chemical formula (II), L and Z are the same as in the above chemical formula (I), R 1 represents a substituent, n is R 1 This is the number of elements, and represents an integer of 0 or greater than or equal to 1. R1 If there are multiple instances, they may be identical or different from one another.

[0043] [ka]

[0044] In the above chemical formula (III), L, Z, R 1 and n are the same as in chemical formula (II), and respectively represent L, Z, and R in chemical formula (II). 1 It may be the same as or different from n.

[0045] In the compositions of the present disclosure, the plurality of compounds in which Z in chemical formula (I) is different from each other may include, for example, the compound represented by the following chemical formula 3-PATAT-C3 and the compound represented by the following chemical formula 3-CATAT-C3.

[0046] [ka]

[0047] [ka]

[0048] The compositions of this disclosure may or may not contain other substances other than the compound represented by chemical formula (I), its tautomers, stereoisomers, and salts thereof. The other substances are not particularly limited, but examples include substances contained in the hole transport layer of a photoelectric conversion element described later.

[0049] [2. Photoelectric conversion element] Next, the photoelectric conversion element of the present disclosure will be described with an example. As described above, the photoelectric conversion element of the present disclosure is characterized in that a first electrode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a second electrode are stacked in the order described above, the photoelectric conversion layer includes a perovskite structure, and the hole transport layer includes the composition of the present disclosure.

[0050] The photoelectric conversion element of this disclosure may or may not include other components other than the first electrode, hole transport layer, photoelectric conversion layer, electron transport layer, and second electrode. Examples of such other components include a support, which will be described later. Furthermore, the first electrode, hole transport layer, photoelectric conversion layer, electron transport layer, and second electrode may be directly stacked in the order described above, or they may be stacked with other components in between.

[0051] Figure 1 shows a cross-sectional view illustrating an example of the configuration of the photoelectric conversion element 10 disclosed herein. Note that Figure 1 is a schematic representation, with some omissions and exaggerations for the sake of clarity.

[0052] As shown in Figure 1, the photoelectric conversion element 10 has a laminated structure in which a first electrode 12, a hole transport layer 13, a photoelectric conversion layer 14, an electron transport layer 15, and a second electrode 16 are stacked on a support (also called a substrate or base material) 11 in this order.

[0053] The following will provide a detailed explanation of each component of the photoelectric conversion element 10, with examples. In addition, the manufacturing method of the photoelectric conversion element 10 (the method for forming each component of the photoelectric conversion element 10) and the method of using the photoelectric conversion element 10 will also be explained with examples.

[0054] [2-1.Support] The support 11 is not particularly limited, and may be any substrate suitable for use in photoelectric conversion elements such as general solar cells. Examples of such substrates include glass, plastic plates, plastic films, and inorganic crystals. Furthermore, substrates on which at least one type of film, such as a metal film, semiconductor film, conductive film, or insulating film, is formed on part or all of the surface of the substrate can also be suitably used as the support 11. The size, thickness, etc., of the support 11 are not particularly limited, and may be the same as or similar to those of general photoelectric conversion elements such as general solar cells.

[0055] [2-2. First Electrode] The first electrode 12 is, for example, a layer that supports the hole transport layer 13 and has the function of extracting holes from the photoelectric conversion layer 14. The first electrode 12 also functions as, for example, a cathode (positive electrode).

[0056] The first electrode 12 may be formed directly on the support 11, for example. The first electrode 12 may be a transparent electrode formed from a conductor, for example. The transparent electrode is not particularly limited, but examples include a tin-doped indium oxide (ITO) film, an impurity-doped indium oxide (In2O3) film, an impurity-doped zinc oxide (ZnO) film, a fluorine-doped tin dioxide (FTO) film, a laminated film formed by laminating two or more of these, gold, silver, copper, aluminum, tungsten, titanium, chromium, nickel, and cobalt. These may be used individually or as a mixture of two or more, and may be a single layer or a laminate. These films may also function as a diffusion barrier layer, for example. The thickness of the first electrode 12 is not particularly limited, but it is preferable to adjust it so that the sheet resistance is 5 to 15 Ω / □ (per unit area). The method for forming the first electrode 12 is not particularly limited, but it can be obtained by known film formation methods depending on the material to be formed. Furthermore, the shape of the first electrode 12 is not particularly limited, but may be, for example, a film or a lattice-like mesh. The method for forming the first electrode 12 on the support 11 is not particularly limited, but may be a known method, for example, vacuum deposition such as vacuum deposition or sputtering is preferred. The first electrode 12 may also be patterned. The patterning method is not limited to two methods, but examples include immersion in a laser or etching solution, or patterning using a mask during vacuum deposition, and any of these methods may be used in this disclosure. Furthermore, the first electrode 12 may be used in combination with metal wiring or the like for the purpose of lowering the electrical resistance. The material of the metal wiring (metal lead wire) is not particularly limited, but examples include aluminum, copper, silver, gold, platinum, and nickel. The metal lead wire can be formed on the first substrate by, for example, deposition, sputtering, or crimping, and then a layer of ITO or FTO is provided on top of it, or provided on top of ITO or FTO to be used in combination.

[0057] [2-3. Hole transport layer] The hole transport layer 13 contains at least one selected from the group consisting of the compound represented by chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound includes multiple types of compounds in which Z in the following chemical formula (I) is different from each other. The hole transport layer 13 can be formed, for example, by adsorbing the multiple types of compounds onto the first electrode 12. The method for adsorbing the compound represented by chemical formula (I) onto the first electrode 12 is not particularly limited, but for example, the compound represented by chemical formula (I) may be dissolved in a solvent and brought into contact with the first electrode 12 to bond. The bond between the compound represented by chemical formula (I) and the first electrode 12 is not particularly limited and may be a physical bond or a chemical bond. The type of bond is also not particularly limited and may be a hydrogen bond, ester bond, chelate bond, etc. The solvent for dissolving the compound represented by chemical formula (I) is also not particularly limited and may be, for example, water and an organic solvent, or a mixed solvent of both. Examples of organic solvents include alcohols such as methanol, ethanol, and 2-propanol; ethers such as diethyl ether and diisopropyl ether; ketones such as acetone and methyl isobutyl ketone; esters such as ethyl acetate, isobutyl acetate, and γ-butyrolactone; heterocyclic compounds such as tetrahydrofuran and thiophene; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide; sulfones such as diethyl sulfone and sulfolane; nitriles such as acetonitrile and 3-methoxypropionitrile; aromatic compounds such as benzene, toluene, and chlorobenzene; halogenated solvents such as dichloromethane and chloroform; and fluorinated solvents such as chlorofluorocarbon and hydrochlorofluorocarbon. These may be used individually or in mixtures of two or more.

[0058] The specific method for adsorbing the compound represented by chemical formula (I) onto the first electrode 12 to form an electron transport layer is not particularly limited, but known methods such as dipping, spraying, spin coating, and bar coating can be cited. The temperature during adsorption is not particularly limited, but -20°C to 100°C is preferred, and 0°C to 50°C is more preferred. The adsorption time is also not particularly limited, but for example, 1 second to 48 hours is preferred, and 10 seconds to 1 hour is more preferred.

[0059] Furthermore, washing may or may not be performed after the adsorption treatment. The washing method is not particularly limited, and any known method may be used as appropriate. Heat treatment may or may not be performed after the adsorption treatment or washing. The temperature of the heat treatment is not particularly limited, but 50°C to 150°C is preferred, and 70°C to 120°C is more preferred. The heat treatment time is not particularly limited, but 1 second to 48 hours is preferred, and 10 seconds to 1 hour is more preferred. This heat treatment may be performed, for example, in the atmosphere or in a vacuum.

[0060] When adsorbing the compound represented by the general formula (I) onto the first electrode 12, a co-adsorbent may also be used. Specific examples of co-adsorbents include phosphonic acid compounds such as n-butylphosphonic acid, n-hexylphosphonic acid, n-decylphosphonic acid, n-octadecylphosphonic acid, 2-ethylhexylphosphonic acid, methoxymethylphosphonic acid, 3-acryloyloxypropylphosphonic acid, 11-hydroxyundecylphosphonic acid, and 1H,1H,2H,2H-perfluorophosphonic acid, as well as acetic acid, propionic acid, isobutyric acid, nonanoic acid, fluoroacetic acid, α-chloropropionic acid, and glyoxylic acid. These may be used individually or in a mixture of two or more types.

[0061] The method for adsorbing the co-adsorbent onto the first electrode 12 is not particularly limited, but a method of dissolving it in a solvent before adsorption is preferred, similar to the compound represented by chemical formula (I). The solvent is also not particularly limited, but may be the same as the solvent exemplified for the compound represented by chemical formula (I). Furthermore, the co-adsorbent may be adsorbed by first adsorbing the compound represented by chemical formula (I) onto the substrate, and then immersing the first electrode 12 in a solvent in which the co-adsorbent is dissolved, or it may be used after mixing and dissolving it together with the compound represented by chemical formula (I) in an organic solvent.

[0062] Furthermore, the hole transport layer 13 may include other layers besides the layer containing the composition of the present disclosure. The other layer may be, for example, a p-type metal oxide semiconductor layer containing a p-type metal oxide semiconductor. In the photoelectric conversion element 10 of Figure 1, the hole transport layer 13 includes a p-type metal oxide semiconductor layer 13-1 and a hole transport material layer 13-2. The hole transport material layer 13-2 is a layer containing the composition of the present disclosure. As shown in the figure, the p-type metal oxide semiconductor layer 13-1 and the hole transport material layer 13-2 are stacked on the first electrode 12 in the order described above. The p-type metal oxide semiconductor layer 13-1 is stacked on the main surface of the first electrode 12 on the side of the photoelectric conversion layer 14.

[0063] The p-type metal oxide semiconductor used in the p-type metal oxide semiconductor layer 13-1 is preferably a semiconductor material formed from a metal oxide that transports holes. Specifically, examples include oxides formed by using nickel, copper, aluminum, etc., alone or in mixtures. The p-type metal oxide semiconductor layer 13-1 may be a single layer or a multilayer, and in the case of a multilayer, it may have a porous shape in which semiconductor fine particles of different particle sizes are coated in multiple layers. In the porous shape, the particle size of the semiconductor fine particles is not particularly limited, but is preferably 3 to 100 nm, and more preferably 5 to 70 nm. The film thickness of the p-type metal oxide semiconductor layer 13-1 is not particularly limited, but is preferably 1 to 1000 nm, and more preferably 10 to 500 nm. There are no particular restrictions on the method of forming the p-type metal oxide semiconductor layer 13-1, and may be either vacuum deposition such as sputtering or ion plating, or wet deposition such as sol-gel.

[0064] The surface of the p-type metal oxide semiconductor layer 13-1 may or may not be covered with a very thin insulating layer, as long as it does not impair hole transport. This insulating layer is not particularly limited, but examples include insulating metal oxides formed by using oxides of aluminum, magnesium, silicon, niobium, strontium, barium, titanium, zinc, vanadium, etc., either individually or in combination. The thickness of this insulating metal oxide is not particularly limited, but a thin thickness is preferable, preferably 1 to 20 nm, and more preferably 2 to 10 nm. The method for forming the insulating layer made of the insulating metal oxide is not particularly limited and may be vacuum deposition such as sputtering or ion plating, or wet deposition such as sol-gel deposition.

[0065] The compound represented by the chemical formula (I) may be formed, for example, as a monolayer on the p-type metal oxide semiconductor layer 13-1. That is, the hole transport material layer 13-2 in Figure 10 may be a monolayer containing the composition of this disclosure.

[0066] The hole transport layer 13 may or may not contain an insulating compound. At least a portion of the insulating compound and at least a portion of the hole transport material may or may not be in contact with the main surface of the first electrode 12 on the photoelectric conversion layer 14 side. In addition, the hole transport material functions as a hole transporter in the hole transport layer 13. By including an insulating compound in addition to the hole transport material as the material of the hole transport layer 13, the degree of scattering of light incident on the hole transport layer 13 increases. As a result, it is presumed that the amount of light taken up by the photoelectric conversion layer 14 increases, and consequently the photoelectric conversion efficiency increases.

[0067] Insulating compounds are compounds that do not conduct electricity well, and generally, for example, 10 8 ~10 18It exhibits a resistivity of Ω·cm. The insulating compound used in the hole transport layer 13 can be, for example, at least one selected from metal oxides, metal nitrides, insulating organic compounds, and organic-inorganic hybrid compounds. An example of the metal oxide is silica (SiO2, refractive index 1.48, volume resistivity 1 × 10⁻⁶). 16 (Ω·cm), alumina (Al2O3, refractive index 1.64, volume resistivity 1×10⁻⁶) 14 (Ω·cm), Zirconia (ZrO2), Ceria (CeO2, refractive index 2.13, volume resistivity 1×10⁻⁶) 10 Magnesia (MgO), yttria (Y2O3), refractive index 1.18, volume resistivity 1 × 10⁻⁶ (Ω·cm), 13 (Ω·cm), tantalum pentoxide (Ta2O5), hafnia (HfO2), strontium oxide, lanthanum oxide, barium titanate (BaTiO3, refractive index 2.43~2.49, volume resistivity 1×10⁻⁶) 12 Examples include Ω·cm, strontium titanate (SrTiO3), etc. Examples of the metal nitride include aluminum nitride (AlN), silicon nitride (SiN), aluminum gallium nitride (AlGaN), boron nitride (BN), etc. Examples of the insulating organic compound include acrylic resin, epoxy resin, polystyrene, etc. The organic-inorganic hybrid compound is, for example, a compound having both carbon atoms and silicon atoms, and is preferably a compound having both a siloxane bond and a substructure having carbon atoms (such as a hydrocarbon group), specifically silsesquioxane, etc. Among these, it is particularly preferable to use metal oxides as insulating compounds.

[0068] In the hole transport layer 13, the volume resistivity of the insulating compound is 1 × 10⁻⁶. 8 Preferably Ω·cm or more, 1 × 10 9 Ω·cm or larger is more preferable, 1 × 10 10 A value of Ω·cm or higher is even more preferable. Furthermore, the volume resistivity of the insulating compound is 1 × 10⁻⁶. 18 Preferably less than Ω·cm, and 1 × 10 17 Ω·cm or less is more preferable, and 1 × 10 16 A value of Ω·cm or less is even more preferable.

[0069] In the hole transport layer 13, the refractive index of the insulating compound is preferably 1.20 or higher, and more preferably 1.40 or higher. The refractive index of the insulating compound is, for example, 2.50 or lower. The refractive index of the insulating compound can be measured, for example, by the critical angle method.

[0070] There are no limitations on the method for forming the hole transport layer 13 containing the insulating compound, and it can be appropriately selected depending on the purpose, but a wet film formation method or a wet printing method is preferred. As for the wet film formation method, a method of preparing a dispersion of the insulating compound powder or sol and applying it is preferred. There are no particular limitations on the wet film formation method, and it can be appropriately selected depending on the purpose, and examples include the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, etc. As for the wet printing method, there are no particular limitations, but various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used.

[0071] There are no particular limitations on the method for producing the fine particles of the insulating compound. For example, if the insulating compound is a metal oxide, methods such as solid-phase reaction using known raw materials such as oxides or carbonates, coprecipitation, hydrothermal synthesis, and sol-gel methods can be used. The shape of the fine particles is also not particularly limited and can be spherical, irregular, rod-shaped, or plate-shaped anisotropic shapes. In this embodiment, the insulating compound is preferably in the form of particles. When the insulating compound is in the form of particles, the average particle size is preferably 1 to 200 nm, more preferably 1 to 100 nm, and even more preferably 1.5 to 50 nm. The average particle size of the insulating compound is calculated by measuring the diameter (or major axis if not perfectly round) of 100 particles of the insulating compound using a scanning electron microscope (SEM). When the hole transport layer 13 is formed, the average particle size can be measured by taking a picture of the cross-section of the hole transport layer 13 with an SEM and measuring the diameter (or major axis if not perfectly round) of 100 particles of the insulating compound. Before forming the hole transport layer 13, the average particle size of the insulating compound used to form the hole transport layer 13 may be measured.

[0072] There are no particular limitations on the method for preparing the dispersion of the insulating compound, and a suitable method can be selected depending on the purpose. For example, a method of mechanically grinding the insulating compound using a known milling apparatus or the like is one possible method. By this preparation method, the dispersion of the insulating compound can be prepared by dispersing the particulate insulating compound alone, or a mixture of the insulating compound and a resin, in a dispersion medium (for example, water, an organic solvent, or a mixture thereof).

[0073] The resin used in the dispersion is not particularly limited, but examples include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic acid esters, and methacrylic acid esters, silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, polyester resins, cellulose ester resins, cellulose ether resins, urethane resins, phenolic resins, epoxy resins, polycarbonate resins, polyarylate resins, polyamide resins, and polyimide resins. These may be used individually or in combination of two or more.

[0074] Examples of dispersion media in the dispersion of the insulating compound include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of alcohol solvents include methanol, ethanol, isopropyl alcohol, and α-terpineol. Examples of ketone solvents include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of ester solvents include ethyl formate, ethyl acetate, and n-butyl acetate. Examples of ether solvents include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane. Examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of 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. These may be used individually or in combination of two or more.

[0075] A dispersion containing the insulating compound, or a paste containing the insulating compound obtained by a sol-gel method or the like, may contain, for example, an acid, a surfactant, a chelating agent, etc., to prevent the re-aggregation of the insulating compound particles. Examples of the acid include hydrochloric acid, nitric acid, and acetic acid. Examples of the surfactant include polyoxyethylene octylphenyl ether. Examples of the chelating agent include acetylacetone, 2-aminoethanol, and ethylenediamine. In addition, it is also effective to add a thickener to the dispersion or paste, for example, to improve film-forming properties. Examples of the thickener include polyethylene glycol, polyvinyl alcohol, and ethylcellulose.

[0076] [2-4. Photoelectric Conversion Layer] The photoelectric conversion layer 14 is not particularly limited and may be the same as a photoelectric conversion layer used in a general photoelectric conversion element such as a solar cell. The photoelectric conversion layer 14 includes, for example, a perovskite compound. The perovskite compound may be, for example, an organic-inorganic perovskite compound represented by the following chemical formula (IV). X α Y β Z γ ...(IV)

[0077] In the chemical formula (IV) above, the ratio of α:β:γ is 3:1:1 or close to it, and β and γ represent integers greater than 1. X represents a halogen ion, Y represents an organic compound having an amino group, and Z represents a metal ion. The photoelectric conversion layer 14 containing the perovskite compound is preferably arranged adjacent to the electron transport layer 15, which will be described later. Note that the ratio of α:β:γ does not necessarily have to be strictly 3:1:1, for example, 3:1.05:0.95.

[0078] There are no particular restrictions on X in the aforementioned chemical formula (IV), and it can be appropriately selected depending on the purpose. Examples include halogen ions such as chlorine, bromine, and iodine. These may be used individually or in combination of two or more.

[0079] In the above chemical formula (IV), Y can be an alkylamine compound ion (an organic compound having an amino group) such as methylamine, ethylamine, n-butylamine, or formamidine, or, not limited to organic compounds, an alkali metal ion such as cesium, potassium, or rubidium. Alkylamine compound ions and alkali metal ions may be used individually or in combination of two or more. Furthermore, organic (alkylamine compound ions) and inorganic (alkali metal ions) can be used in combination; for example, cesium ions and formamidine may be used together.

[0080] In the aforementioned chemical formula (IV), Z is not particularly limited and can be appropriately selected depending on the purpose. Examples include metals such as lead, indium, antimony, tin, copper, and bismuth. These may be used individually or in combination of two or more. Lead is particularly preferred, and among these, the combination of lead and tin is especially preferred. Furthermore, the perovskite layer preferably exhibits a layered perovskite structure in which layers made of metal halides and layers in which organic cation molecules are arranged are alternately stacked. The perovskite layer may contain alkali metals. The inclusion of at least alkali metals in the perovskite layer is advantageous in that it increases the output. Examples of alkali metals include cesium, rubidium, and potassium. Among these, cesium is preferred.

[0081] As described above, the photoelectric conversion layer 14 may be a perovskite layer formed from a perovskite compound. There are no particular restrictions on the method for forming such a perovskite layer, and it can be appropriately selected depending on the purpose. For example, one method is to coat a solution in which a metal halide and an alkylamine halide are dissolved or dispersed, and then dry it.

[0082] Furthermore, methods for forming the perovskite layer include, for example, a two-step precipitation method in which a solution containing dissolved or dispersed metal halides is applied, dried, and then immersed in a solution containing dissolved alkylamine halides to form a perovskite compound. Other methods for forming a perovskite layer include, for example, applying a solution in which metal halides and alkylamine halides are dissolved or dispersed, while adding a poor solvent (a solvent with low solubility) for the perovskite compound to precipitate crystals. Other methods for forming a perovskite layer include, for example, depositing metal halides in a gas filled with methylamine.

[0083] A particularly preferred method for forming a perovskite layer is to coat a solution containing dissolved or dispersed metal halides and alkylamine halides while adding a poor solvent for the perovskite compound to precipitate crystals. There are no particular limitations on the method of coating these solutions, and they can be appropriately selected depending on the purpose. Examples include immersion, spin coating, spraying, dipping, roller coating, and air knife coating. Alternatively, the solution may be coated using a supercritical fluid such as carbon dioxide for precipitation. Examples of poor solvents that can be used in the method of precipitating crystals by adding the poor solvents described above include hydrocarbons such as n-hexane and n-octane, alcohols such as methanol, ethanol, and 2-propanol, ethers such as diethyl ether and diisopropyl ether, ketones such as acetone and methyl isobutyl ketone, esters such as ethyl acetate, isobutyl acetate, and γ-butyrolactone, nitriles such as acetonitrile and 3-methoxypropionitrile, aromatic hydrocarbon compounds such as benzene, toluene, and chlorobenzene, halogenated solvents such as dichloromethane and chloroform, and fluorinated solvents such as chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons.

[0084] The thickness of the photoelectric transport layer 14 (for example, a light absorption layer, such as a perovskite layer) is not particularly limited, but from the viewpoint of further suppressing performance degradation due to defects and delamination, 50 to 1200 nm is preferred, and 200 to 1000 nm is more preferred.

[0085] A method for forming a perovskite layer may include, for example, a surface treatment step (surface treatment step) using a salt formed from one or more cations and one or more anions. Examples of the cations include inorganic cations such as lithium, sodium, potassium, rubidium, cesium, magnesium, and calcium; ammonium cations, methylamine, ethylamine, n-butylamine, isopentylamine, neopentylamine, formamidine, acetamidine, benzylamine, 2-phenylethylamine, 2-(4-methoxyphenyl)ethylamine, 4-fluorobenzylamine, 2-(4-fluorophenyl)ethylamine, 1,4-phenylenediamine, 5-aminovaleric acid, metamine, ethylenediamine, p-xylylenediamine, m-xylylenediamine, and 1,2-amide. Examples of cations include organic compounds having an amino group such as mantanediamine, 1,3-adamantanediamine, N,N-dimethylethylenediamine, 1,3-diaminopropane, 1,4-diazabicyclo[2.2.2]octane, guanidine, aniline, pyrrole, imidazole, 1-ethylimidazole, 2-ethylimidazole, benzmidazole, morpholin, pyrrolidine, pyrazole, triazole, and carbazole; and cations obtained from heterocycles containing nitrogen atoms such as pyridine, pyrazine, pyridazine, pyrimidine, quinoline, isoquinoline, phenanthroline, 2,2'-bipyridyl, and 4,4'-bipyridyl. Examples of the anions include halogen ions such as fluoride ions, chloride ions, bromide ions, and iodide ions; carboxylate ions such as formate ions and acetate ions; isocyanate ions, thiocyanate ions, tetrafluoroborate ions, hexafluorophosphate ions; and trifluoromethanesulfonylimide ions.

[0086] The salt comprising the cation and the anion is preferably soluble in one or more solvents. Examples of such solvents include alcohols such as isopropanol (2-propanol), ethanol (EtOH), methanol (MeOH), and butanol; nitriles such as acetonitrile and propionitrile; and aromatic solvents such as toluene, chlorobenzene, and 1,2-dichlorobenzene. One solvent may be used alone, or two or more may be used in combination.

[0087] The surface treatment step is carried out by applying a solution of the dissolved salt onto the formed perovskite layer and then drying it. There are no particular restrictions on the method of applying the solution, and it can be appropriately selected depending on the purpose. Examples include immersion, spin coating, spraying, dipping, roller coating, and air knife coating. Heat treatment may also be performed after application. If heating is performed, the heating temperature is preferably 50 to 200°C, and more preferably 70 to 180°C. The heating time is preferably 1 to 150 minutes, and more preferably 5 to 60 minutes. There are no particular restrictions on the film thickness to which the solution is applied.

[0088] [2-5.Electron transport layer] There are no particular restrictions on the material used for the electron transport layer 15, and it can be appropriately selected according to the purpose, but semiconductor materials are preferred. There are no particular restrictions on the semiconductor material, and known materials can be used, such as elemental semiconductors, compound semiconductors, and organic n-type semiconductors.

[0089] The aforementioned single semiconductor is not particularly limited, but examples include silicon, germanium, and the like.

[0090] The aforementioned compound semiconductors are not particularly limited, but examples include metal chalcogenides, specifically oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum, etc.; sulfides of cadmium, zinc, lead, silver, antimony, bismuth, etc.; selenides of cadmium, lead, etc.; tellurides of cadmium, etc. Other compound semiconductors include phosphides of zinc, gallium, indium, cadmium, etc., gallium arsenide, copper-indium selenide, copper-indium sulfide, etc.

[0091] The aforementioned organic n-type semiconductor is not particularly limited, but examples include perylenetetracarboxylic anhydride, perylenetetracarboxydiimide compounds, naphthalenediimide-bithiophene copolymer, benzobisimidazobenzophenanthroline polymer, C 60 , C 70 PCBM([6,6]-phenyl-C 61 Examples include frehlan compounds such as methyl butyrate, carbonyl bridge-bithiazole compounds, ALq3 (tris(8-quinolinolato)aluminum), triphenylene bipyridyl compounds, silole compounds, oxadiazole compounds, etc.

[0092] Among the aforementioned materials used in the electron transport layer 15, organic n-type semiconductors are particularly preferred.

[0093] The materials used to form the electron transport layer 15 may be used alone or in combination of two or more materials. Furthermore, there are no particular restrictions on the crystal type of the semiconductor material; it can be appropriately selected according to the purpose, and may be single crystal, polycrystalline, or amorphous.

[0094] There are no particular restrictions on the thickness of the electron transport layer 15, and it can be appropriately selected depending on the purpose, but 5 nm to 1000 nm is preferred, and 10 nm to 700 nm is more preferred.

[0095] There are no particular restrictions on the method for forming the electron transport layer 15, and it can be appropriately selected depending on the purpose. For example, methods such as forming a thin film in a vacuum (vacuum deposition method) and wet deposition methods can be used. Examples of vacuum deposition methods include sputtering, pulsed laser deposition (PLD), ion beam sputtering, ion-assisted deposition, ion plating, vacuum evaporation, atomic layer deposition (ALD), and chemical vapor deposition (CVD). Examples of wet deposition methods include methods of forming by coating a solvent containing dissolved electron transport material, and in the case of oxide semiconductors, the sol-gel method. The sol-gel method is a method in which a gel is prepared from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then densification is promoted by heat treatment. When using the sol-gel method, there are no particular restrictions on the method of applying the sol solution, and it can be appropriately selected according to the purpose. Examples include the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, and gravure coating method. Wet printing methods include letterpress, offset, gravure, intaglio, rubber plate, and screen printing. Furthermore, the temperature during the heat treatment after applying the sol solution is preferably 80°C or higher, and more preferably 100°C or higher.

[0096] After forming the electron transport layer 15, an electron injection layer (hole blocking layer) may be formed between it and the second electrode 16. Examples of materials used for the electron injection layer include bathocuproine (BCP), which may be doped with cesium. The electron injection layer is preferably 1 to 100 nm in thickness, and more preferably 3 to 20 nm.

[0097] [2-6. Second Electrode] The second electrode 16 (which may be, for example, a back electrode) is a layer that has the function of extracting electrons from the photoelectric conversion layer 14 via the electron transport layer 15. The second electrode 16 is also a layer that acts as an anode (negative electrode).

[0098] The second electrode 16 may be formed directly on the electron transport layer (also called the electron injection layer) 15. Furthermore, the material of the second electrode 16 is not particularly limited; for example, the same material as that used for the first electrode 12 can be used. The shape, structure, and size of the second electrode 16 are not particularly limited and can be appropriately selected according to the purpose. Examples of materials for the second electrode 16 include metals, carbon compounds, conductive metal oxides, and conductive polymers.

[0099] Examples of the metal include platinum, gold, silver, copper, and aluminum. Examples of the carbon compound include graphite, fullerene, carbon nanotubes, and graphene. Examples of the conductive metal oxide include ITO, FTO, and ATO. Examples of the conductive polymer include polythiophene and polyaniline. The material used to form the second electrode 16 may be used alone or in combination of two or more materials.

[0100] The second electrode 16 can be formed on the electron transport layer 15 by methods such as coating, laminating, vacuum deposition, CVD, or bonding, depending on the type of material used and the type of hole transport layer 13.

[0101] Furthermore, in the photoelectric conversion element 10 of this embodiment, it is preferable that at least one of the first electrode 12 and the second electrode 16 is substantially transparent. When using the photoelectric conversion element 10 of this embodiment, it is preferable to make the electrodes transparent and allow incident light to enter from the electrode side. In this case, it is preferable to use a light-reflecting material for the back electrode (the electrode opposite to the transparent electrode, for example, the second electrode 16), and metals, glass with a conductive oxide deposited on it, plastics, thin metal films, etc., are preferably used. Providing an anti-reflective layer on the electrode on the incident light side is also an effective means.

[0102] The configuration of the photoelectric conversion element 10 is not limited to that shown in Figure 1. For example, the support 11 may be positioned on the opposite side from Figure 1 (above the second electrode 16 in Figure 1), and the second electrode 16, electron transport layer 15, photoelectric conversion layer 14, hole transport layer 13, and first electrode 12 may be stacked on the support 11 in the order described above. Also, as mentioned above, other components may or may not exist between each layer of the support 11, first electrode 12, hole transport layer 13, photoelectric conversion layer 14, electron transport layer 15, and second electrode 16. Furthermore, although an example in which the first electrode 12 is a transparent electrode and the second electrode 16 is a back electrode has been described, the photoelectric conversion element 10 is not limited to this. For example, in the photoelectric conversion element 10, the opposite may be true: the first electrode 12 is a back electrode and the second electrode 16 is a transparent electrode.

[0103] [2-7. Sealing] The photoelectric conversion element 10 (e.g., solar cell) of this embodiment is preferably sealed to protect the device (photoelectric conversion element 10 of this embodiment) from water and oxygen. The sealing structure is not particularly limited, but may be the same as that of a general photoelectric conversion element (e.g., solar cell). Specifically, for example, the sealing material may be applied only to the outer periphery of the photoelectric conversion element 10 of this embodiment and covered with glass or film, the sealing material may be applied to the entire surface of the photoelectric conversion element 10 of this embodiment and covered with glass or film, or the sealing material may be applied to the entire surface of the photoelectric conversion element 10 of this embodiment.

[0104] There are no particular restrictions on the material of the sealing member; it can be appropriately selected according to the purpose. For example, epoxy resin or acrylic resin is preferably used and cured, but it is acceptable if it is not cured at all, or if only a part of it is cured.

[0105] The epoxy resin is not particularly limited, but examples include water-dispersible, solvent-free, solid, heat-curing, curing agent-mixed, and UV-curing types. Among these, the heat-curing and UV-curing types are preferred, and the UV-curing type is more preferred. Even with UV-curing types, heating is possible, and it is preferable to heat even after UV curing. Specific examples of epoxy resins include bisphenol A type, bisphenol F type, novolac type, cyclic aliphatic type, long-chain aliphatic type, glycidylamine type, glycidyl ether type, and glycidyl ester type. These may be used individually or in combination of two or more. It is also preferable to mix the epoxy resin with a curing agent and various additives as needed. Existing epoxy resin compositions can be used in this embodiment. Among them, epoxy resin compositions developed and commercially available for solar cells and organic EL elements can be used particularly effectively in this embodiment. Examples of commercially available epoxy resin compositions include TB3118, TB3114, TB3124, TB3125F (manufactured by ThreeBond Corporation), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyōritsu Chemical Industry Co., Ltd.), WB90US(P), and WB90US-HV (manufactured by Moresco).

[0106] The acrylic resin is not particularly limited, but for example, those developed and commercially available for solar cells and organic EL elements can be effectively used. Examples of commercially available acrylic resin compositions include TB3035B and TB3035C (manufactured by ThreeBond Corporation).

[0107] There are no particular restrictions on the curing agent, and it can be appropriately selected depending on the purpose, but examples include amine-based, acid anhydride-based, polyamide-based, and other curing agents. Examples of amine-based curing agents include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of acid anhydride-based curing agents include phthalic anhydride, tetra and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, hetic anhydride, and dodecenyl succinic anhydride. Examples of other curing agents include imidazoles and polymer captans. These may be used alone or in combination of two or more.

[0108] There are no particular restrictions on the aforementioned additives, and they can be appropriately selected according to the purpose. Examples include fillers, gap fillers, polymerization initiators, desiccants (hygroscopic agents), curing accelerators, coupling agents, softening agents, colorants, flame retardant aids, antioxidants, and organic solvents. Among these, fillers, gap fillers, curing accelerators, polymerization initiators, and desiccants (hygroscopic agents) are preferred, with fillers and polymerization initiators being more preferred. By including fillers as additives, it is possible to suppress the intrusion of moisture and oxygen, and furthermore, to obtain effects such as reduced volume shrinkage during curing, reduced outgassing during curing or heating, improved mechanical strength, and control of thermal conductivity and fluidity. Therefore, including fillers as additives is very effective in maintaining stable output in various environments.

[0109] Furthermore, regarding the output characteristics and durability of photoelectric conversion elements, the effects of outgassing generated during the curing or heating of the sealing material, in addition to the effects of infiltrating moisture and oxygen, cannot be ignored. In particular, the effects of outgassing generated during heating have a significant impact on the output characteristics when stored in a high-temperature environment. By incorporating fillers, gap fillers, and desiccants into the sealing material, these materials themselves can suppress the infiltration of moisture and oxygen, and the amount of sealing material used can be reduced, thereby reducing outgassing. Incorporating fillers, gap fillers, and desiccants into the sealing material is effective not only during curing but also when storing photoelectric conversion elements in a high-temperature environment.

[0110] There are no particular restrictions on the filler material, and it can be appropriately selected depending on the purpose. Examples include crystalline or amorphous silica, silicate minerals such as talc, inorganic fillers such as alumina, aluminum nitride, silicon nitride, calcium silicate, and calcium carbonate. Among these, hydrotalcite is particularly preferred. These may be used individually or in combination of two or more.

[0111] The average primary particle size of the filler is not particularly limited, but is preferably 0.1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. When the average primary particle size of the filler is within the above preferred range, the effect of suppressing the intrusion of moisture and oxygen can be sufficiently obtained, the viscosity becomes appropriate, adhesion to the substrate and degassing performance are improved, and it is also effective in controlling the width of the sealing part and workability.

[0112] The content of the filler is preferably 10 to 90 parts by mass, and more preferably 20 to 70 parts by mass, relative to the entire sealing member (100 parts by mass). By having the content of the filler within the above preferred range, sufficient effect in suppressing the penetration of moisture and oxygen is obtained, the viscosity becomes appropriate, and adhesion and workability are also good.

[0113] The gap agent is also called a gap control agent or spacer agent. By including a gap agent as an additive, it becomes possible to control the gap of the sealed portion. For example, when a sealing member is applied to a first substrate or a first electrode, and a second substrate is placed on top of it to perform sealing, the gap of the sealed portion can be easily controlled because the gap agent is mixed into the sealing member, causing the gap to match the size of the gap agent.

[0114] The gap filler is not particularly limited, but for example, it is preferably granular with a uniform particle size and high solvent resistance and heat resistance, and can be appropriately selected depending on the purpose. The gap filler is preferably one that has high affinity with epoxy resin and has a spherical particle shape. Specifically, glass beads, silica fine particles, organic resin fine particles, etc. are preferred. These may be used individually or in combination of two or more. The particle size of the gap filler can be selected according to the gap of the sealing part to be set, but is preferably 1 μm to 100 μm, and more preferably 5 μm to 50 μm.

[0115] The polymerization initiator is not particularly limited, but examples include polymerization initiators that initiate polymerization using heat or light, and can be appropriately selected depending on the purpose. Examples include thermal polymerization initiators and photopolymerization initiators. Thermal polymerization initiators are compounds that generate active species such as radicals and cations when heated, and examples include azo compounds such as 2,2'-azobisbutyronitrile (AIBN) and peroxides such as benzoyl peroxide (BPO). Examples of thermal cationic polymerization initiators include benzenesulfonic acid esters and alkylsulfonium salts. In the case of epoxy resins, photocationic polymerization initiators are preferably used. When a photocationic polymerization initiator is mixed with an epoxy resin and irradiated with light, the photocationic polymerization initiator decomposes, generating acid, which causes polymerization of the epoxy resin, and the curing reaction proceeds. Photocationic polymerization initiators have the effect of low volume shrinkage during curing, not being affected by oxygen inhibition, and having high storage stability.

[0116] Examples of photocatalytic polymerization initiators include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metacerone compounds, and silanol-aluminum complexes. Additionally, photoacid generators that generate acid upon irradiation with light can also be used as polymerization initiators. These photoacid generators act as acids that initiate cationic polymerization and include ionic sulfonium salts and iodonium salts, among others, consisting of a cation and anion. These may be used individually or in combination of two or more.

[0117] The amount of polymerization initiator added is not particularly limited and may vary depending on the material used, but is preferably 0.5 parts by mass or more and 10 parts by mass or less, and more preferably 1 part by mass or more and 5 parts by mass or less, relative to the entire sealing member (100 parts by mass). By adding the amount within the above preferred range, curing can proceed appropriately, the amount of uncured material remaining can be reduced, and excessive outgassing can be prevented.

[0118] The desiccant (also called a moisture absorber) is a material that has the function of physically or chemically adsorbing and absorbing moisture, and by incorporating it into the sealing member, moisture resistance can be further enhanced and the effects of outgassing can be reduced. There are no particular restrictions on the desiccant, and it can be appropriately selected according to the purpose, but particulate materials are preferred, and examples of inorganic water-absorbing materials include calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolites. Among these, zeolites, which have a high moisture absorption capacity, are preferred. These may be used alone or in combination of two or more.

[0119] The curing accelerator (also called a curing catalyst) is a material that speeds up the curing process and is mainly used with thermosetting epoxy resins. There are no particular restrictions on the curing accelerator, and it can be appropriately selected depending on the purpose. Examples include tertiary amines or tertiary amine salts such as DBU (1,8-diazabicyclo(5,4,0)-undecene-7) and DBN (1,5-diazabicyclo(4,3,0)-nonene-5), imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, and phosphines or phosphonium salts such as triphenylphosphine and tetraphenylphosphonium·tetraphenylborate. These may be used alone or in combination of two or more.

[0120] The coupling agent is not particularly limited as long as it is a material that enhances molecular bonding strength, and can be appropriately selected depending on the purpose. Examples include silane coupling agents. Specifically, examples include silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyltrimethoxysilane. These may be used alone or in combination of two or more.

[0121] In this embodiment, for example, a sheet-like adhesive can be used. A sheet-like adhesive is, for example, one in which a resin layer has been formed in advance on a sheet using a sealing resin. The sheet can be made of glass, a film with high gas barrier properties, or the like. Alternatively, the sheet-like adhesive may be formed using only a sealing resin. It is also possible to attach the sheet-like adhesive to a sealing film. In this case, it is also possible to create a structure in which a hollow portion is provided in the sheet constituting the sheet-like adhesive attached to the sealing film before bonding it to the device.

[0122] When sealing is performed using the aforementioned sealing film, it is positioned opposite the support so as to sandwich the photoelectric conversion device. There are no particular restrictions on the shape, structure, size, or type of the substrate of the sealing film, and it can be appropriately selected according to the purpose. The sealing film has a barrier layer formed on the surface of the substrate that prevents the passage of moisture and oxygen, and this layer may be formed on one side of the substrate or on both sides.

[0123] The barrier layer may be composed of a material whose main components are, for example, a metal oxide, a metal, or a mixture formed from a polymer and a metal alkoxide. Examples of the metal oxide include aluminum oxide, silicon oxide, and aluminum; examples of the polymer include polyvinyl alcohol, polyvinylpyrrolidone, and methylcellulose; and examples of the metal alkoxide include tetraethoxysilane, triisopropoxyaluminum, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane.

[0124] The barrier layer may be transparent or opaque, for example. Furthermore, the barrier layer may be a single layer formed from a combination of the above materials, or it may be a multi-layered structure. Known methods can be used to form the barrier layer, including vacuum deposition methods such as sputtering, dipping, roll coating, screen printing, spraying, and gravure printing.

[0125] [2-8. Wiring] In this embodiment, the photoelectric conversion element 10 (e.g., solar cell) preferably has lead wires (wirings) connected to the first electrode 12 and the back electrode of the second electrode in order to efficiently extract the current generated by light. The lead wires are connected to the first electrode and the second electrode using a conductive material such as solder, silver paste, or graphite. The conductive material may be used alone, or in a mixture of two or more types or in a laminated structure. Furthermore, the area to which the lead wires are attached may be covered with an acrylic resin or epoxy resin for physical protection.

[0126] Lead wires are a general term for wires used to electrically connect power sources, electronic components, etc., in electrical circuits. Examples include vinyl-coated wires and enameled wires.

[0127] The photoelectric conversion element 10 described above offers the advantage of achieving both excellent photoelectric conversion characteristics and excellent photodurability.

[0128] [2-9. Applications] The applications and methods of use of the photoelectric conversion element disclosed herein are not particularly limited, and it can be widely used in the same applications as general photoelectric conversion elements (e.g., general solar cells). The photoelectric conversion element of this embodiment (e.g., solar cell) can be applied to a power supply device by combining it with, for example, a circuit board that controls the generated current. Examples of devices that utilize a power supply device include electronic desktop calculators and solar-powered radio-controlled watches. It is also possible to apply the solar cell of this embodiment as a power supply device to mobile phones, electronic paper, thermometers and hygrometers, etc. Furthermore, it can be used as an auxiliary power source to extend the continuous use time of rechargeable or battery-powered electrical appliances, or in combination with secondary batteries for nighttime use. It can also be used as a self-contained power source that does not require battery replacement or power wiring. [Examples]

[0129] The following describes embodiments of this disclosure. However, this disclosure is not limited to the following embodiments.

[0130] [Example 1] The photoelectric conversion element, the solar cell, was fabricated (manufactured) in the following manner.

[0131] First, an ITO glass substrate (a glass substrate with a first electrode formed on it) was prepared. Meanwhile, a DMF solution (0.1 mmol / L) was prepared by adjusting the molar ratio of the following compounds (3-PATAT-C3) and (3-CATAT-C3) to 1:1. 100 μL of this solution was placed on the ITO of the ITO glass substrate and coated using a spin coater (3,000 rpm, 30 seconds) to form a monolayer (hole transport layer) on the ITO (first electrode). Next, a solution was prepared by dissolving cesium iodide (0.738 g), formamidine iodide (7.512 g), methylamine bromide (0.905 g), lead iodide (23.888 g), and lead bromide (1.022 g) in a mixed solvent of DMF (40.0 mL) and dimethyl sulfoxide (DMSO, 12.0 mL). This solution was then coated onto the monolayer (hole transport layer) by spin coating to form a film. The spin coating was performed at 3000 rpm, with chlorobenzene (0.3 mL) added dropwise 30 seconds after the start. The coated film was then heated at 150°C for 10 minutes to obtain a perovskite layer (photoelectric conversion layer). Next, a solution of ethylenediamine hydroiodide (25.5 mg) dissolved in a mixed solvent of 2-propanol (25 mL) and chlorobenzene (25 mL) was deposited on the perovskite layer by spin coating (4,000 rpm, 23 seconds). A passivation layer was formed on the perovskite layer by heating the film at 100°C for 5 minutes. Then, C was applied to the passivation layer. 60A photoelectric conversion element was fabricated by vacuum deposition using 20 nm (electron transport layer), vasocuproin (BCP, 8 nm) (electron injection layer), and Ag (100 nm) (second electrode) in that order. Furthermore, Nagase ChemteX XNR5516 was coated on the outer periphery of the photoelectric conversion element, bonded to glass under an inert gas atmosphere, and irradiated with UV light to fabricate a sealed device. After device fabrication, the solar cell characteristics of the photoelectric conversion element were evaluated. The performance is shown in Table 1 below. In addition, a continuous light irradiation test was performed at AM 1.5 G, 100 mW / cm². 2 A continuous irradiation test of 500 hours was conducted using a Suntest XLS+ adjusted to the specified light intensity. The maintenance rate of the conversion efficiency measured before and after this test is shown in Table 1 below.

[0132] The photoelectric conversion characteristics of the photoelectric conversion element fabricated in Example 1 were measured using a method compliant with the output measurement method for silicon crystalline solar cells specified in JISC8913:1998. A solar simulator (SMO-250III, manufactured by Spectrometer Co., Ltd.) combined with an air mass filter equivalent to AM1.5G was used with a secondary reference Si solar cell at 100 mW / cm². 2 The light intensity was adjusted to serve as the light source for measurement, and while irradiating a test sample of a perovskite solar cell (the photoelectric conversion element fabricated in Example 1) with light, the IV curve characteristics were measured using a source meter (Keithley Instruments Inc., 2400 general-purpose source meter). From the IV curve characteristics measurement, the short-circuit current (Isc), open-circuit voltage (Voc), fill factor (FF), short-circuit current density (Jsc), and photoelectric conversion efficiency (PCE) were determined.

[0133] Equation 1: Short-circuit current density (Jsc; mA / cm²) 2 )=Isc(mA) / Effective photosensitive area S(cm 2 ) Equation 2: Photoelectric conversion efficiency (PCE; %) = Voc(V) × Jsc(mA / cm) 2 ) × FF × 100 / 100 (mW / cm 2 )

[0134] [ka]

[0135] [ka]

[0136] [Example 2] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was changed to a DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 3:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0137] [Example 3] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was changed to a DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 9:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0138] [Example 4] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was changed to a DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:3. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0139] [Example 5] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was replaced with a DMF solution (0.1 mmol / L) in which the compounds (3-iso-PATAT-C3) and (3-iso-CATAT-C3) were adjusted to a molar ratio of 1:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0140] [ka]

[0141] [ka]

[0142] [Example 6] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was replaced with a DMF solution (0.1 mmol / L) in which the compounds (3-Cl-iso-PATAT-C3) and (3-Cl-iso-CATAT-C3) were adjusted to a molar ratio of 1:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0143] [ka]

[0144] [ka]

[0145] [Example 7] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was replaced with a DMF solution (0.1 mmol / L) in which the compounds (4-PATI-C3) and (4-CATI-C3) were adjusted to a molar ratio of 1:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0146] [ka]

[0147] [ka]

[0148] [Example 8] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) in which the compounds (3-PATAT-C3) and (3-CATAT-C3) were adjusted to a molar ratio of 1:1 was replaced with a DMF solution (0.1 mmol / L) in which the compounds (MeO-2PACz) and (1-CATAT-C3) were adjusted to a molar ratio of 1:1. The photoelectric conversion characteristics were then evaluated. The results are shown in Table 1.

[0149] [ka]

[0150] [ka]

[0151] [Comparative Example 1] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) prepared by adjusting the molar ratio of compound (3-PATAT-C3) to compound (3-CATAT-C3) to 1:1 was replaced with a DMF solution (0.1 mmol / L) of compound (3-PATAT-C3) alone, and the photoelectric conversion characteristics were evaluated. The results are shown in Table 1.

[0152] [Comparative Example 2] A device was fabricated in the same manner as in Example 1, except that the DMF solution (0.1 mmol / L) containing the compounds (3-PATAT-C3) and (3-CATAT-C3) adjusted to a molar ratio of 1:1 was replaced with a DMF solution (0.1 mmol / L) containing the compound (MeO-2PACz), and the photoelectric conversion characteristics were evaluated. The results are shown in Table 1.

[0153] [Table 1]

[0154] [Example 9] In Example 1, instead of placing 100 μL of a DMF solution (0.1 mmol / L) prepared by adjusting the molar ratio of the compound (3-PATAT-C3) and the compound (3-CATAT-C3) to 1:1 onto the ITO of an ITO glass substrate (a glass substrate on which the first electrode is formed) and forming a monolayer (hole transport layer) on the ITO (first electrode) using a spin coater (3,000 rpm, 30 seconds), an ITO-NiO glass substrate was used, in which 10 nm of NiO was sputtered onto the ITO of the ITO glass substrate. The device was fabricated in the same manner as in Example 1, except that a monolayer of the DMF solution (0.1 mmol / L) prepared by adjusting the molar ratio of the compound (3-PATAT-C3) and the compound (3-CATAT-C3) to 1:1 was formed on the NiO of the ITO-NiO substrate, and the photoelectric conversion characteristics were evaluated. The results are shown in Table 2.

[0155] [Example 10] In Example 9, an ITO-NiO glass substrate was prepared by sputtering 10 nm of NiO onto the ITO of the ITO glass substrate. A DMF solution (0.1 mmol / L) containing the compounds (3-PATAT-C3) and (3-CATAT-C3) adjusted to a molar ratio of 1:1 was then applied to the NiO of the ITO-NiO substrate to form a monolayer. Average particle size 50nm A device was fabricated in the same manner as in Example 9, except that a solution obtained by diluting a dispersion containing 20 wt% alumina and 2-propanol as the dispersion medium 50 times with 2-propanol was added to the hole transport layer, and a hole transport layer containing the hole transport material and insulating compound was formed using a spin coater (3,000 rpm, 30 seconds) and a hot plate (100°C, 15 minutes). The photoelectric conversion characteristics were then evaluated. The results are shown in Table 2.

[0156] [Table 2]

[0157] As described above, the solar cells (photoelectric conversion elements) of Examples 1 to 10, in which the hole transport layer contains the composition of the present disclosure, exhibited high photoelectric conversion efficiency (PCE), and even after 500 hours of continuous irradiation testing (light irradiation), the retention rate of the photoelectric conversion efficiency exceeded 90%. In other words, the solar cells of Examples 1 to 10 achieved both excellent photoelectric conversion characteristics and excellent photodurability. On the other hand, the solar cells of Comparative Examples 1 to 2, which contained only one type of hole transport material (compound represented by the chemical formula (I)), had high initial photoelectric conversion efficiency, but the retention rate of the photoelectric conversion efficiency after 500 hours of continuous irradiation testing (light irradiation) was lower than that of Examples 1 to 10.

[0158] The present disclosure has been described above using embodiments and examples. However, the present disclosure is not limited to the embodiments and examples described above, and may be combined, modified, or selected as necessary and appropriate, without departing from the spirit of the present disclosure.

[0159] This disclosure may also be presented, for example, as shown in the following addendum; however, the following addendum is illustrative and this disclosure is not limited to these forms. (Note 1) A composition, The composition comprises at least one selected from the group consisting of a compound represented by the following chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound comprises multiple types of compounds in which Z in the following chemical formula (I) is different from each other. [ka] In the above chemical formula (I), Ar has a structure that includes an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms. Ar may or may not have substituents other than -LZ. -LZ may be one or more, and if there are multiple, each L and each Z may be the same or different from one another. Each L is either an atomic group bonding Ar and Z, or a covalent bond. Each Z is a group that can form chemical bonds or hydrogen bonds with a metal oxide. (Note 2) The composition according to Appendix 1, wherein L in the chemical formula (I) is a divalent linking group or single bond that connects Ar and Z. (Note 3) The composition according to Appendix 1 or 2, wherein in the plurality of compounds in the chemical formula (I) where Z is different from each other, the Ar in the chemical formula (I) has the same structure. (Note 4) The composition according to any one of the appendices 1 to 3, wherein, in the plurality of compounds in which Z in chemical formula (I) is different from each other, Z in at least one of the compounds in chemical formula (I) is a phosphonic acid group. (Note 5) The composition according to Appendix 4, wherein the phosphonic acid group is at least one of a phosphoryl group and a phosphate group. (Note 6) The composition according to any of the appendices 1 to 5, wherein in the chemical formula (I), the Ar is represented by the following chemical formula (I-1). [ka] In the above chemical formula (I-1), Ar 11 This is an atomic group containing a cyclic structure, and the cyclic structure may be an aromatic ring or an unaromatic ring, a monoring, a fused ring or a spiroring, and may or may not contain heteroatoms among the atoms constituting the ring. Ar 12 This is an aromatic ring, and the atoms constituting the ring may or may not contain heteroatoms. Ar 12 It consists of one or more atoms in Ar 11 Share with Ar 11 It may be integrated with it, Ar 12 There may be one or more of them, and if there are multiple, they may be the same or different from each other. (Note 7) In the above chemical formula (I-1), the Ar 11 However, the composition described in Appendix 6 is represented by any of the following chemical formulas (a1) to (a10). [ka] (Note 8) In the above chemical formula (I-1), each Ar 12 However, the compositions described in Appendix 6 or 7, each represented by the following chemical formula (b). [ka] In the above chemical formula (b), Carbon atom C 1 and C 2 This is the Ar in the chemical formula (I-1) 11 It also serves as a part of the atoms constituting the cyclic structure in, The aforementioned R 1 This is a hydrogen atom, X in the chemical formula (I). 1, or substituent, the substituent may or may not contain a hydrogen atom, and at least one of the hydrogen atoms in the substituent is X in the chemical formula (I). 1 It may also be replaced with Each of the above R 11 These may be the same or different from each other, and each may be a hydrogen atom or a substituent, or two adjacent R atoms. 11 These may form a fused ring together with the benzene ring to which they are bonded. Each of the above R 11 It may or may not have substituents. (Note 9) The composition according to Appendix 8, wherein the chemical formula (b) is represented by any of the following chemical formulas (b1) to (b7). [ka] In the above chemical formulas (b1) to (b7), C 1 , C 2 and R 1 These are the same as chemical formula (b) above. (Note 10) The composition according to any one of the appendices 1 to 9, wherein the plurality of compounds in which Z in the chemical formula (I) is different from each other include at least one of the compound represented by the following chemical formula (II) and the compound represented by the following chemical formula (III). [ka] In the above chemical formula (II), L and Z are the same as in the above chemical formula (I), R 1 represents a substituent, n is R 1 This is the number of elements, and represents an integer of 0 or greater than or equal to 1. R 1 If there are multiple instances, they may be identical or different from one another. [ka] In the above chemical formula (III), L, Z, R1 and n are the same as in chemical formula (II), and respectively represent L, Z, and R in chemical formula (II). 1 It may be the same as or different from n. (Note 11) The substituent R in the above chemical formulas (II) and (III) 1 The composition according to Appendix 10, wherein each is independently an alkyl group, an alkoxy group, an aryl group, a heterocyclic ring, or a halogen atom. (Note 12) The composition according to any one of the appendices 1 to 11, wherein the plurality of compounds in which Z in the chemical formula (I) is different from each other include a first compound in which Z in the chemical formula (I) is a phosphonic acid group and a second compound in which Z in the chemical formula (I) is a carboxyl group. (Note 13) The composition according to Appendix 12, wherein the content of the second compound is 10 to 1000 parts by mass per 100 parts by mass of the first compound. (Note 14) The first compound is at least one selected from the group consisting of compounds represented by the following chemical formula 3PATAT-C3, compounds represented by the following chemical formula 3-iso-PATAT-C3, compounds represented by the following chemical formula Cl-iso-PATAT-C3, compounds represented by the following chemical formula 4-PATI-C3, and compounds represented by the following chemical formula MeO-2PACz, and salts thereof. The second compound is at least one selected from the group consisting of compounds represented by the following chemical formulas: 3-CATAT-C3, 3-iso-CATAT-C3, 3-Cl-iso-CATAT-C3, 4-CATI-C3, and 1-CATAT-C3, and their salts. The composition described in Appendix 12 or 13. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] (Note 15) The composition according to Appendix 14, wherein the first compound is at least one of the compound represented by the chemical formula 3PATAT-C3 and a salt thereof, and the second compound is at least one of the compound represented by the chemical formula 3-CATAT-C3 and a salt thereof. (Note 16) The composition according to Appendix 14, wherein the first compound is at least one of the compound represented by the chemical formula 3-iso-PATAT-C3 and a salt thereof, and the second compound is at least one of the compound represented by the chemical formula 3-iso-CATAT-C3 and a salt thereof. (Note 17) The composition according to Appendix 14, wherein the first compound is at least one of the compound represented by the chemical formula Cl-iso-PATAT-C3 and a salt thereof, and the second compound is at least one of the compound represented by the chemical formula Cl-iso-CATAT-C3 and a salt thereof. (Note 18) The composition according to Appendix 14, wherein the first compound is at least one of the compound represented by the chemical formula 4-PATI-C3 and a salt thereof, and the second compound is at least one of the compound represented by the chemical formula 4-CATI-C3 and a salt thereof. (Note 19) The composition according to Appendix 14, wherein the first compound is at least one of the compound represented by the following chemical formula MeO-2PACz and its salt, and the second compound is at least one of the compound represented by the chemical formula 1-CATAT-C3 and its salt. (Note 20) The first electrode, hole transport layer, photoelectric conversion layer, electron transport layer, and second electrode are stacked in the order described above. The aforementioned photoelectric conversion layer includes a perovskite structure, The hole transport layer is characterized by comprising the composition described in any one of the appendices 1 to 19. (Note 21) The photoelectric conversion element according to Appendix 20, wherein the hole transport layer includes a p-type metal oxide semiconductor. (Note 22) The photoelectric conversion element according to appendix 20 or 21, comprising insulating nanoparticles between the hole transport layer and the perovskite layer. (Note 23) The photoelectric conversion element according to Appendix 22, wherein the median particle size of the insulating nanoparticles is in the range of 1 to 100 nm. (Note 24) A photoelectric conversion element described in any of appendices 20 to 23, which is a solar cell. [Industrial applicability]

[0160] As described above, this disclosure provides a composition usable in photoelectric conversion elements that can achieve both excellent photoelectric conversion characteristics and excellent photodurability, and a photoelectric conversion element using the same. However, the use of the composition of this disclosure is not limited to photoelectric conversion elements and may be used in any application. The photoelectric conversion element of this disclosure is useful, for example, as a solar cell. The uses and methods of use of the photoelectric conversion element of this disclosure are not particularly limited and can be applied to a wide range of fields in the same uses and methods as general photoelectric conversion elements (e.g., general solar cells). [Explanation of symbols]

[0161] 10 Photoelectric conversion element 11 Support 12 First electrode 13 Hole transport layer 13-1 p-type metal oxide semiconductor layer 13-2 Hole transport material layer 14 Photoelectric conversion layer 15 Electron transport layer 16 Second electrode

Claims

1. A composition, The composition comprises at least one selected from the group consisting of a compound represented by the following chemical formula (I), its tautomers, stereoisomers, and salts thereof, and the compound comprises multiple types of compounds in which Z in the following chemical formula (I) is different from each other. [Chemistry I] In the aforementioned chemical formula (I), Ar has a structure that includes an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms. Ar may or may not have substituents other than -L-Z. -L-Z may be one or more, and if there are multiple, each L and each Z may be the same or different from one another. Each L is either an atomic group bonding Ar and Z, or a covalent bond. Each Z is a group that can form chemical bonds or hydrogen bonds with a metal oxide.

2. The composition according to claim 1, wherein L in the chemical formula (I) is a divalent linking group or single bond that connects Ar and Z.

3. The composition according to claim 1, wherein in the plurality of compounds in which Z in the chemical formula (I) is different from each other, Ar in the chemical formula (I) has the same structure.

4. The composition according to claim 1, wherein in the plurality of compounds in which Z in chemical formula (I) is different from each other, Z in at least one of the compounds is a phosphonic acid group.

5. The composition according to claim 4, wherein the phosphonic acid group is at least one of a phosphoryl group and a phosphate group.

6. The composition according to claim 1, wherein the plurality of compounds, each having different Z in the chemical formula (I), comprises a first compound in which Z in the chemical formula (I) is a phosphonic acid group, and a second compound in which Z in the chemical formula (I) is a carboxyl group.

7. The composition according to claim 6, wherein the content of the second compound is 10 to 1000 parts by mass with respect to 100 parts by mass of the first compound.

8. The composition according to claim 1, wherein the plurality of compounds in which Z in the chemical formula (I) is different from each other include at least one of the compound represented by the following chemical formula (II) and the compound represented by the following chemical formula (III). 【Chemistry II】 In the above chemical formula (II), L and Z are the same as in the above chemical formula (I), R １ This represents a substituent, n is R １ This is the number of elements, and represents an integer of 0 or more. R １ If there are multiple instances, they may be identical or different from one another. 【Chemistry III】 In the aforementioned chemical formula (III), L, Z, R １ and n are the same as in chemical formula (II), and respectively represent L, Z, and R in chemical formula (II). １ It may be the same as or different from n.

9. The substituent R in the above chemical formulas (II) and (III) １ The composition according to claim 9, wherein each is independently an alkyl group, an alkoxy group, an aryl group, a heterocyclic ring, or a halogen atom.

10. The first compound is at least one selected from the group consisting of compounds represented by the following chemical formula 3-PATAT-C3, compounds represented by the following chemical formula 3-iso-PATAT-C3, compounds represented by the following chemical formula Cl-iso-PATAT-C3, compounds represented by the following chemical formula 4-PATI-C3, and compounds represented by the following chemical formula MeO-2PACz and their salts. The second compound is at least one selected from the group consisting of the following compounds: compounds represented by the chemical formula 3-CATAT-C3, compounds represented by the chemical formula 3-iso-CATAT-C3, compounds represented by the chemical formula 3-Cl-iso-CATAT-C3, compounds represented by the chemical formula 4-CATI-C3, and compounds represented by the chemical formula 1-CATAT-C3 and their salts. The composition according to claim 6. 【Chemical Formula 3 - PATAT - C3】 【Chemical Formula 3 - iso - PATAT - C3】 【Chemical 3-Cl-iso-PATAT-C3】 【Chemical 4-PATI-C3】 【MeO-2PACz】 【Chem.3-CATAT-C3】 【Chem.3-iso-CATAT-C3】 【Chemical 3-Cl-iso-CATAT-C3】 【Chemical Formula 4-CATI-C3】 【Chemistry 1-CATAT-C3】

11. The first electrode, hole transport layer, photoelectric conversion layer, electron transport layer, and second electrode are stacked in the order described above. The aforementioned photoelectric conversion layer includes a perovskite structure, The hole transport layer comprises the composition described in any one of claims 1 to 10, making it a photoelectric conversion element.

12. The photoelectric conversion element according to claim 11, wherein the hole transport layer includes a p-type metal oxide semiconductor.

13. The photoelectric conversion element according to claim 11, further comprising insulating nanoparticles between the hole transport layer and the perovskite layer.

14. The photoelectric conversion element according to claim 13, wherein the median particle size of the insulating nanoparticles is in the range of 1 to 100 nm.

15. The photoelectric conversion element according to claim 11, which is a solar cell.

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