Photoelectric conversion element

Abstract

Provided is a photoelectric conversion element having excellent characteristics and capable of forming a high-quality perovskite layer without using a poor solvent method. A photoelectric conversion element in which a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode are laminated in this order, the hole transport layer containing a compound represented by chemical formula (I), the photoelectric conversion layer containing a perovskite compound, and the hole transport layer containing a compound represented by chemical formula (I). And the perovskite compound is formed from a raw material including at least one of formamidine and a salt thereof. In the chemical formula (I), Ar1 is a structure containing an aromatic ring, the atoms constituting the aromatic ring may contain a heteroatom or may not contain a heteroatom, Ar1 may have a substituent other than-L1-X1 or may not have a substituent other than-L1-X1, the number of-L1-X1 may be one or a plurality, if a plurality of-L1-X1 may be provided, each L1 and each X1 may be the same as or different from each other, and if a plurality of-L1-X1 may be provided, each L1 and each X1 may be the same as or different from each other. Each L1 is an atomic group or a covalent bond that bonds Ar1 and X1, and each X1 is a group capable of accepting and imparting an electric charge between the first electrode and each X1.

Description

Technical Field

[0001] The present disclosure relates to a photoelectric conversion element. Background Art

[0002] In recent years, solar power generation has attracted considerable attention as a clean energy source, and the development of solar cells has continued to advance. Among these, solar cells using perovskite materials for their light-absorbing layers are rapidly gaining attention as low-cost, next-generation solar cells. For example, Non-Patent Document 1 reports on a solution-based solar cell using perovskite materials for its light-absorbing layer. Furthermore, Non-Patent Document 2 reports on the high efficiency of solid-state perovskite solar cells.

[0003] Furthermore, when forming a perovskite layer, a method of adding a poor solvent dropwise before drying is known as a method for promoting crystallization. This poor solvent method is effective for achieving high conversion efficiency in small cells because it produces high-quality crystals. However, it has the disadvantage of being difficult to apply to coating methods other than spin coating.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-patent document 1: Journal of the American Chemical Society, 2009, 131, 6050-6051.

[0007] Non-patent document 2: Science, 2012, 388, 643-647. Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Although the poor solvent method has the above-mentioned disadvantages, even if a method other than the poor solvent method is used, it is difficult to obtain a high-quality perovskite layer comparable to that of the poor solvent method.

[0010] Therefore, an object of the present disclosure is to provide a photoelectric conversion element that can form a high-quality perovskite layer without using a poor solvent method and has excellent characteristics.

[0011] Technical means to solve the problem

[0012] To achieve the above object, the photoelectric conversion element disclosed herein is characterized in that:

[0013] The first electrode, the electron transport layer, the photoelectric conversion layer, the hole transport layer and the second electrode are stacked in the order described,

[0014] The hole transport layer comprises a compound represented by the following chemical formula (I):

[0015] The photoelectric conversion layer includes a perovskite compound, and the perovskite compound is a perovskite compound formed from a raw material including at least one of formamidine and a salt thereof.

[0016] [Chemical I]

[0017]

[0018] In the chemical formula (I),

[0019] Ar 1 is a structure containing an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms,

[0020] Ar 1 Can have except -L 1 -X 1 Substituents other than -L 1 -X 1 Substituents other than

[0021] -L 1 -X 1 It can be one or more. In the case of multiple, each L 1 and each X 1 They can be the same or different from each other.

[0022] Each L 1 To Ar 1 With X 1 The bonded atomic groups are either covalent bonds,

[0023] Each X 1 They are respectively groups capable of accepting and donating charges between the first electrode and the first electrode.

[0024] Effects of the Invention

[0025] According to the present disclosure, a photoelectric conversion element can be provided that can form a high-quality perovskite layer without using a poor solvent method and has excellent characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [ Figure 1 ] Figure 1 This is a cross-sectional view showing an example of the structure of the photoelectric conversion element of the present disclosure.

[0027] [ Figure 2 ] Figure 2 This is a 1H NMR chart of compound 3PATAT produced in Examples.

[0028] [ Figure 3 Figure 3 is a 13C NMR chart of compound 3 PATAT manufactured in an example.

[0029] [ Figure 4 Figure 4 is a 31P NMR chart of compound 3 PATAT manufactured in an example. DETAILED DESCRIPTION

[0030] Next, the present disclosure is described in more detail citing examples. However, the present disclosure is not limited by the following description.

[0031] In the present disclosure, unless otherwise specified, "mass%" and "weight%" can be replaced with each other, and "mass parts" and "weight parts" can be replaced with each other.

[0032] In the present disclosure, "on" or "on the surface of" can be a state of directly contacting on or on the surface of, or can be a state of being separated by other constituent members or the like.

[0033] [Photoelectric conversion element]

[0034] As described above, the photoelectric conversion element of the present disclosure is characterized in that a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode are laminated in the order, the hole transport layer contains a compound represented by the chemical formula (I), the photoelectric conversion layer contains a perovskite compound, and the perovskite compound is a perovskite compound formed from a raw material containing at least one of formamidine and a salt thereof.

[0035] The photoelectric conversion element of the present disclosure can contain other constituent members than the first electrode, the electron transport layer, the photoelectric conversion layer, the hole transport layer, and the second electrode, or can not contain them. For example, the photoelectric conversion element of the present disclosure can contain a support body as described later. In addition, the constituent members adjacent to each other among the first electrode, the electron transport layer, the photoelectric conversion layer, the hole transport layer, and the second electrode can be laminated in a state of directly contacting each other without being separated by other constituent members, or can be laminated with being separated by other constituent members or the like therebetween.

[0036] Hereinafter, the structure of the photoelectric conversion element of the present disclosure and each constituent member are described in more detail citing examples. However, the photoelectric conversion element of the present disclosure is not limited to the following examples. Furthermore, the following mainly describes a case where the photoelectric conversion element of the present disclosure is a solar cell.

[0037] Figure 1 An example of the structure of the photoelectric conversion element of the present disclosure is shown. Furthermore, Figure 1 ​​For the sake of convenience, the figures are schematically drawn with appropriate omissions, exaggerations, etc. As shown in the figure, the photoelectric conversion element of the present disclosure is a perovskite solar cell, and has an inverted structure.

[0038] [Support 11]

[0039] The support 11 is not particularly limited. For example, a substrate that can be used for a general photoelectric conversion element such as a solar cell can be suitably used. Examples of such substrates include glass, plastic plates, plastic films, and inorganic crystals. Furthermore, substrates having at least one of a metal film, a semiconductor film, a conductive film, and an insulating film formed on part or all of the surface of these substrates can also be suitably used as the support 11. The size, thickness, etc. of the support 11 are also not particularly limited. For example, the size, thickness, etc. of the support 11 can be the same as or based on that of a general photoelectric conversion element such as a solar cell.

[0040] [First electrode 12]

[0041] The first electrode 12 is, for example, a layer that supports the hole transport layer 13 and extracts holes from the photoelectric conversion layer 14. The first electrode 12 is, for example, a layer that functions as a cathode (positive electrode).

[0042] The first electrode 12 can be formed directly on the support 11, for example. The first electrode 12 can be a transparent electrode formed of an electrically conductive body, for example. As the transparent electrode, there is no particular limitation, and examples that can be given include a tin-doped indium oxide (indium tin oxide (ITO)) film, an impurity-doped indium oxide (In2O3) film, an impurity-doped zinc oxide (ZnO) film, a fluorine-doped tin oxide (FTO) film, a laminated film in which two or more of these are laminated, gold, silver, copper, aluminum, tungsten, titanium, chromium, nickel, cobalt, and the like. These can be used alone or in combination of two or more, and can be a single layer or a laminate. In addition, these films can be a film that functions as a diffusion preventing layer, for example. The thickness of the first electrode 12 is not particularly limited, and is preferably adjusted so that the sheet resistance is 5 Ω / D to 15 Ω / D (per unit area), for example. The method of forming the first electrode 12 is not particularly limited, and can be obtained by a known film formation method according to the material used for the formation, for example. In addition, the shape of the first electrode 12 is not particularly limited, and can be a film shape or can be formed in a lattice shape such as a grid shape, for example. The method of forming the first electrode 12 on the support 11 is not particularly limited, and can be a known method, and is preferably vacuum film formation such as vacuum evaporation or sputtering, for example. In addition, the first electrode 12 can also use a pattern-formed electrode. As the method of pattern formation, there is no particular limitation, and examples that can be given include a method using laser or immersion in an etching solution, a method of pattern formation using a mask at the time of vacuum film formation, and the like, and any of these can be used in the present disclosure. In addition, the first electrode 12 can also be used in combination with a metal wiring or the like for the purpose of reducing the resistance value. As the material of the metal wiring (metal lead), there is no particular limitation, and examples that can be given include aluminum, copper, silver, gold, platinum, nickel, and the like. The metal lead can be formed on the first substrate by evaporation, sputtering, crimping, or the like, and an ITO or FTO layer can be provided thereon or on the ITO or FTO, whereby the combination can be achieved, for example.

[0043] [hole transport layer 13]

[0044] As described above, the hole transport layer 13 contains the compound represented by Chemical Formula (I). The compound represented by Chemical Formula (I) has a group X 1, and therefore can function as a hole transport compound. The compound represented by the chemical formula (I) can function as a hole transport compound (hereinafter also referred to as "single molecule hole transport compound") that forms a monolayer. The single molecule hole transport compound, for example, is preferably an anchor group that forms a chemical bond with the first electrode (for example, ITO as a transparent electrode, etc.) in an inverted structure. As the anchor group, for example, a phosphonic acid group, a carboxyl group, a sulfonic acid group, a boric acid group, a trihalogenated silane group, a trialkoxysilane group, or a trihydroxysilane group can be cited. Among these, a phosphonic acid group, a trihalogenated silane group, and a trialkoxysilane group are particularly preferred. For example, the group X in the chemical formula (I) that can accept and give charge between the first electrode 1 Preferably, the group is a group capable of forming a chemical bond or a hydrogen bond with the first electrode (i.e., an anchoring group). In addition, in the present disclosure, "chemical bond" refers to a bond between atoms or ions that form a molecule, crystal, etc., and can be, for example, a covalent bond, an ionic bond, or a metallic bond, or a bond in which multiple forms of these bonds exist in a mixture.

[0045] In the chemical formula (I), -L 1 -X 1 The number of is not particularly limited and can be, for example, in the range of 1 to 4.

[0046] In the photoelectric conversion element of the present disclosure, for example, in the chemical formula (I), each X 1 They can be phosphonic acid group (-P=O(OH)2), carboxyl group (-COOH), sulfonic acid group (-SO3H), boric acid group (-B(OH)2), trihalosilyl group (-SiX3, wherein X is a halide group) or trialkoxysilyl group (-Si(OR)3, wherein R is an alkyl group).

[0047] In the photoelectric conversion element of the present disclosure, for example, in the chemical formula (I), the Ar 1 It can be represented by the following chemical formula (I-1).

[0048] [ChemI-1]

[0049]

[0050] In the chemical formula (I-1),

[0051] Ar 11 is an atomic group containing a cyclic structure, wherein the cyclic structure may be an aromatic ring or a non-aromatic ring, a monocyclic ring, a condensed ring, or a spirocyclic ring, and the atoms constituting the ring may or may not contain heteroatoms,

[0052] Ar 12 is an aromatic ring, and the atoms constituting the ring may or may not contain heteroatoms,

[0053] Ar 12 Can be used with Ar 11 Share more than one atom with Ar 11 Integration,

[0054] Ar 12 There may be one or more than one, and in the case of a plurality of them, they may be the same as or different from each other.

[0055] Ar 12 The number of is not particularly limited and can be, for example, in the range of 1 to 4.

[0056] In the photoelectric conversion element of the present disclosure, for example, in the chemical formula (I-1), the Ar 11 It can be represented by any of the following chemical formulas (a1) to (a10).

[0057] [a1-a10]

[0058]

[0059] In the photoelectric conversion element of the present disclosure, for example, in the chemical formula (I-1), each of the Ar 12 They can be represented by the following chemical formula (b).

[0060] [b]

[0061]

[0062] In the chemical formula (b),

[0063] Carbon atom C 1 and carbon atom C 2 Also serving as the Ar in the chemical formula (I-1) 11 part of the atoms of the ring structure,

[0064] The R 1 is a hydrogen atom, X in the chemical formula (I) 1 or a substituent, wherein the substituent may contain a hydrogen atom or may not contain a hydrogen atom, and at least one hydrogen atom in the substituent may be replaced by X in the chemical formula (I) 1 replace,

[0065] The R 11 They may be the same or different and may be hydrogen atoms or substituents, or two adjacent R 11 They can become one with the benzene ring to which they are bonded to form a condensed ring.

[0066] The R 11 It may or may not further have a substituent.

[0067] In the photoelectric conversion element of the present disclosure, for example, the chemical formula (b) can be represented by any one of the following chemical formulas (b1) to (b7).

[0068] [b1-b7]

[0069]

[0070] In the chemical formulas (b1) to (b7), C 1 、C 2 and R 1 They are respectively the same as those in the chemical formula (b).

[0071] In the photoelectric conversion element of the present disclosure, specific examples of the compound represented by Chemical Formula (I) include compounds represented by any one of the following Chemical Formulas A-1 to A-23.

[0072] [Chemical A1A4]

[0073]

[0074] [Hua A5A8]

[0075]

[0076] [Hua9A12]

[0077]

[0078] [Hua A13A16]

[0079]

[0080] [Hua A17A20]

[0081]

[0082] [Hua A21A23]

[0083]

[0084] In the chemical formulas A-1 to A-23, each of the R 1 are respectively a hydrogen atom, X in the chemical formula (I) 1 or X in the chemical formula (I) 1 The further substituted substituents may be the same or different from each other, and each R 1 At least one of the X in the chemical formula (I) 1 or X in the chemical formula (I) 1 further substituted substituents, said R2 is a substituent, which may be one, multiple, or absent. In the case of multiple substituents, each R 2 They can be the same or different from each other.

[0085] In the chemical formulas A-1 to A-23, R 1 is X in the chemical formula (I) 1 In the case of further substituted substituents, X 1 The number of can be one or more. 1 is X in the chemical formula (I) 1 In the case of further substituted substituents, for example, X in the chemical formula (I) may be replaced by 1 further substituted alkyl or alkoxy groups.

[0086] In the chemical formulas A-1 to A-23, the substituent R 2 The number of is not particularly limited. 2 For example, they may be an alkyl group, an alkoxy group or a halo group (halogen atom).

[0087] In the photoelectric conversion element of the present disclosure, for example, the compound represented by the chemical formula (I) may be a compound represented by the following chemical formula: 4PATAT, 1-legged-3PATAT, 1-legged-3PATAT-H, 2-legged-3PATAT, 4PATTI-C3, 4PATTI-C4, or 3PATAT.

[0088] [Chemical 4PATAT]

[0089]

[0090] [Chemical 3PATAT1]

[0091]

[0092] [3PATATH]

[0093]

[0094] [Chemical 3PATAT2]

[0095]

[0096] [4PATTI-C3]

[0097]

[0098] [Chemical 4PATTI-C4]

[0099]

[0100] [3PATAT]

[0101]

[0102] In the present disclosure, chain groups or atomic groups (such as hydrocarbon groups such as alkyl groups and unsaturated aliphatic hydrocarbon groups) may be straight-chain or branched unless otherwise specified, and the number of carbon atoms is not particularly limited, for example, it may be 1 to 40, 1 to 32, 1 to 24, 1 to 18, 1 to 12, 1 to 6 or 1 to 2 (2 or more in the case of unsaturated hydrocarbon groups). In addition, in the present disclosure, the number of ring members (the number of atoms constituting the ring) of cyclic groups or atomic groups (such as aromatic rings, aromatic groups, etc., such as aryl groups, heteroaryl groups, etc.) is not particularly limited, for example, it may be 5 to 32, 5 to 24, 6 to 18, 6 to 12 or 6 to 10. In addition, when isomers exist in substituents, etc., unless otherwise specified, any isomer may be used, for example, when referred to as "naphthyl", it may be 1-naphthyl or 2-naphthyl.

[0103] In the present disclosure, the "substituent" is not particularly limited, and examples thereof include alkyl, unsaturated aliphatic hydrocarbon, alkoxy, aralkyl, aryl, heteroaryl, halogen, amino (-NR 1 R 2 、R 1 、R 2 (H, alkyl, aryl), hydroxyl (-OH), mercapto (-SH), alkylthio (-SR 2 、R 2 is an alkyl group), a sulfonyl group, a nitro group, a diazo group, a cyano group, a trifluoromethyl group, and the like.

[0104] In addition, in the present disclosure, when there are isomers such as tautomers or stereoisomers (for example, geometric isomers, conformational isomers, and optical isomers) in a compound, any isomer may be used in the present disclosure unless otherwise specified. In addition, in the present disclosure, when a compound can form a salt, the salt may also be used in the present disclosure unless otherwise specified. The salt may be an acid addition salt, but may also be 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. As the inorganic acid, there is no particular limitation, and examples thereof include: sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypofluoric acid, hypochlorous acid, hypobromous acid, hypoiodous acid, fluorous acid, chlorous acid, bromous acid, iodous acid, fluoric acid, chloric acid, bromic acid, iodic acid, perfluoric acid, perchloric acid, perbromic acid, and periodic acid. The organic acid is also not particularly limited, and examples thereof include: p-toluenesulfonic acid, methanesulfonic acid, oxalic acid, p-bromobenzenesulfonic acid, carbonic acid, succinic acid, citric acid, benzoic acid and acetic acid. As the inorganic base, there is no particular limitation, and examples thereof include: ammonium hydroxide, alkali metal hydroxides, alkaline earth metal hydroxides, carbonates and bicarbonates, and more specifically, examples thereof include: 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 examples thereof include: ethanolamine, triethylamine and tris(hydroxymethyl)aminomethane. The method for producing these salts is also not particularly limited, and for example, they can be produced by a method such as adding the acid or base described above to the compound using a known method. The method for producing these salts can be, for example, a method for producing a device using a compound that has previously formed a salt, or a method for producing a device using a compound before forming a salt and then forming a salt.

[0105] In the present disclosure, the compound represented by the chemical formula (I) can form a salt as described above, and the salt is preferably an acid addition salt. The acid forming the acid addition salt can be an inorganic acid or an organic acid. The inorganic acid and the organic acid are not particularly limited, and specific examples thereof are as described above. The method for producing the acid addition salt is also not particularly limited, and for example, is as described above.

[0106] The method for synthesizing (producing) the compound represented by the chemical formula (I) is not particularly limited, and the compound can be synthesized in the same manner as, or based on, a method for synthesizing compounds having similar structures.

[0107] The method for forming the hole transport layer 13 is not particularly limited. For example, it can be carried out in the same manner as a general photoelectric conversion element, or based on this, or with reference thereto, by an appropriate method. The following mainly describes the case where the compound represented by the chemical formula (I) is a single-molecule hole transport compound. Even if this is not the case, the hole transport layer 13 can be formed by the same method.

[0108] The method for forming the hole transport layer 13 using the monomolecular hole transport compound is not particularly limited. For example, the hole transport layer 13 can be formed by adsorbing the monomolecular hole transport compound on the first electrode 12 to form a monomolecular layer. The method for adsorbing the monomolecular hole transport compound on the first electrode 12 to form a monomolecular layer is not particularly limited. For example, the monomolecular hole transport compound can be dissolved in a solvent and brought into contact with and combined with the first electrode 12. The combination of the monomolecular hole transport compound and the first electrode 12 is not particularly limited and can be a physical combination or a chemical bond. The type of the bond is also not particularly limited and can be any one of a hydrogen bond, an ester bond, a chelate bond, etc. The solvent used to dissolve the monomolecular hole transport compound is also not particularly limited and can be, for example, water or an organic solvent, or both. More specifically, the solvent includes alcohols such as water, 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; heterocyclics 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; halogen-based solvents such as dichloromethane and chloroform; and fluorinated solvents such as chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons. These solvents may be used alone or in combination of two or more.

[0109] There is no particular limitation on the specific method for adsorbing the monomolecular hole transport compound on the first electrode 12 to form a monomolecular layer. For example, known methods such as immersion method, spray method, spin coating method, and rod coating method can be cited. The temperature during adsorption is not particularly limited, and is preferably -20°C to 100°C, and more preferably 0°C to 50°C. The adsorption time is also not particularly limited, and is preferably 1 second to 48 hours, and more preferably 10 seconds to 1 hour. In addition, the adsorption treatment may be washed or not washed after the adsorption treatment, for example. The washing method is also not particularly limited, and for example, known methods can be used as appropriate. In addition, after the adsorption treatment or after the washing, a heat treatment may be performed or not. The temperature of the heat treatment is preferably 50°C to 150°C, and more preferably 70°C to 120°C. The heat treatment time is preferably 1 second to 48 hours, and more preferably 10 seconds to 1 hour. In addition, the heat treatment may be performed, for example, in the atmosphere or in a vacuum.

[0110] When the monomolecular hole transport compound is adsorbed on the first electrode 12, a co-adsorbent may be used in combination. The co-adsorbent may be added when the monomolecular hole transport compound alone cannot completely cover the electrode surface or for the purpose of hindering the interaction between the monomolecular hole transport compounds. Specific examples of the co-adsorbent include: n-butylphosphonic acid, n-hexylphosphonic acid, n-decylphosphonic acid, n-octadecylphosphonic acid, 2-ethylhexylphosphonic acid, methoxymethylphosphonic acid, 3-acryloyloxypropylphosphonic acid, 11-hydroxyundecylphosphonic acid, 1H,1H,2H,2H-perfluorophosphonic acid, 3-aminopropylphosphonic acid, 4-phosphonobutyric acid and other phosphonic acid compounds, acetic acid, propionic acid, isobutyric acid, nonanoic acid, fluoroacetic acid, α-chloropropionic acid, glyoxylic acid, chenodeoxycholic acid, etc. These may be used alone or in combination of two or more.

[0111] The method for adsorbing the co-adsorbent onto the first electrode 12 is not particularly limited, but preferably involves dissolving the co-adsorbent in a solvent similar to the monomolecular hole transport compound and then adsorbing the co-adsorbent. The solvent is also not particularly limited and can be, for example, the same solvent as exemplified for the monomolecular hole transport compound. Furthermore, the co-adsorbent can be adsorbed by immersing the first electrode 12 in a solvent containing the co-adsorbent after the monomolecular hole transport compound is once adsorbed onto the substrate. Alternatively, a substance dissolved in an organic solvent mixed with the monomolecular hole transport compound can be used.

[0112] [Photoelectric conversion layer 14]

[0113] As described above, the photoelectric conversion layer 14 contains a perovskite compound. Furthermore, the perovskite compound in the photoelectric conversion layer 14 is, as described above, a perovskite compound formed from a raw material containing at least one of formamidine and a salt thereof. Other than these, the photoelectric conversion layer 14 and a method of forming the same are not particularly limited, and are described below, for example.

[0114] The perovskite compound contained in the photoelectric conversion layer 14 may, for example, be a compound represented by the following Chemical Formula (III).

[0115] X α Y β Z γ ...(III)

[0116] In the Chemical Formula (III), the ratio of a : b : g may, for example, be 3 : 1 : 1, and b and g represent integers greater than 1. X may, for example, represent a halide ion, Y may, for example, represent a monovalent cation, and Z may, for example, represent a divalent cation. In addition, Y may, for example, represent an organic compound having an amino group, and Z may, for example, represent a metal ion. The perovskite layer (photoelectric conversion layer) 14 is preferably arranged so as to be directly adjacent to the electron transport layer 15 without being interposed by other constituent members. Furthermore, the ratio of a : b : g may, for example, be as 3 : 1.05 : 0.95, and does not necessarily have to be 3 : 1 : 1. The ratio of a : b : g may, for example, be 3 : (0.95 to 1.05) : (0.95 to 1.05).

[0117] There is no particular limitation on X in the Chemical Formula (III), and it can be appropriately selected according to the purpose, and may, for example, be a halide ion such as chlorine, bromine, iodine, or the like. These can be used alone as one kind, or two or more kinds can be used in combination.

[0118] Y in the Chemical Formula (III) may, for example, be an alkylamine compound ion (organic compound having an amino group) such as methylamine, ethylamine, n-butylamine, formamidine, or the like, or may, for example, be an alkali metal ion such as cesium, potassium, rubidium, or the like, without being limited to organic compounds. The alkylamine compound ion or the alkali metal ion can be used alone as one kind, or two or more kinds can be used in combination. In addition, Y may, for example, be used in combination with an organic substance (for example, alkylamine compound ion) and an inorganic substance (for example, alkali metal ion), and may, for example, be used in combination with a cesium ion and formamidine.

[0119] As Z in the chemical formula (III), there is no particular limitation and it can be appropriately selected according to the purpose. For example, metals such as lead, indium, antimony, tin, copper, and bismuth can be listed. One of these can be used alone, or two or more can be used in combination. In particular, lead, and particularly preferably lead and tin are used in combination. In addition, the perovskite layer (photoelectric conversion layer) 14 preferably shows a layered perovskite structure, in which a layer comprising a metal halide and a layer arranged with organic cation molecules are alternately stacked. The perovskite layer may contain an alkali metal. When the perovskite layer contains at least an alkali metal, it is advantageous in terms of increasing the output. As alkali metals, for example, cesium, rubidium, potassium, etc. can be listed. Among these, cesium is preferred.

[0120] As described above, the photoelectric conversion layer 14 may be a perovskite layer formed from a perovskite compound. There are no particular limitations on the method for forming such a perovskite layer, and the method may be appropriately selected depending on the intended purpose. For example, a method may be employed in which a solution containing a metal halide and an alkylamine halide is applied or dispersed therein and then dried. In the present disclosure, as described above, the photoelectric conversion layer 14 comprises a perovskite compound, and the perovskite compound is a perovskite compound formed from a raw material containing at least one of formamidine and a salt thereof. The salt of the formamidine contained in the raw material is preferably at least one selected from the group consisting of formamidine formate, formamidine acetate, formamidine thiocyanate, and formamidine chloride. Examples of the salt of the formamidine include salts formed from formamidine and anions. The anion is not particularly limited. Examples thereof include anions formed from carboxylic acids such as fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, cyanoacetic acid, chloroacetic acid, bromoacetic acid, iodoacetic acid, nitroacetic acid, 2-fluoropropionic acid, pentafluoropropionic acid, and heptafluorobutyric acid; anions formed from dicarboxylic acids such as oxalic acid, pyruvic acid, malonic acid, methylmalonic acid, fluoromalonic acid, succinic acid, and muconic acid; and anions formed from monoester carboxylic acids such as monomethyl malonate, monoethyl malonate, and monobenzyl succinate.

[0121] In addition, as a method for forming a perovskite layer, for example, a solution in which a metal halide is dissolved or dispersed and dried can be enumerated, and then immersed in a solution dissolved with an alkyl amine halide to form a two-stage precipitation method of a perovskite compound. In addition, a solution in which a metal halide and an alkyl amine halide are dissolved or dispersed can be enumerated, while a poor solvent (solvent with little solubility) for the perovskite compound is added to separate out the crystals, etc. can be enumerated. Furthermore, a method in which a metal halide is evaporated in a gas filled with methylamine, etc. can also be enumerated. Furthermore, a method in which a metal halide is evaporated in a gas filled with methylamine, etc. can be enumerated. As a method for applying these solutions, there is no particular limitation, and it can be suitably selected according to the purpose, and can be enumerated: immersion method, spin coating method, spraying method, dip coating method, roller method, air knife method, etc. can be used. In addition, as a method for applying a solution, it can also be a method for separating out in a supercritical fluid using carbon dioxide, etc. Regarding the method of adding the poor solvent to precipitate crystals, examples of the poor solvent used 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, halogen-based solvents such as dichloromethane and chloroform, and fluorine-based solvents such as chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons.

[0122] The thickness of the photoelectric transmission layer 14 (eg, a light absorbing layer such as a perovskite layer) is not particularly limited, but is preferably 50 nm to 1200 nm, more preferably 200 nm to 100 nm, from the viewpoint of further suppressing performance degradation due to defects or peeling.

[0123] [Electron transport layer 15]

[0124] The material used in the electron transport layer 15 is not particularly limited and can be appropriately selected according to the purpose, but is preferably a semiconductor material. The semiconductor material is not particularly limited and widely known materials can be used, such as single semiconductors, compound semiconductors, and organic n-type semiconductors. Among them, metal oxide semiconductors are most suitable.

[0125] The compound semiconductors are not particularly limited, and examples thereof include metal chalcogenides, specifically oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium and lead; and tellurides of cadmium. Other compound semiconductors include phosphides of zinc, gallium, indium, and cadmium; gallium arsenide; copper-indium-selenide; and copper-indium-sulfide.

[0126] The organic n-type semiconductor is not particularly limited, and examples thereof include perylene tetracarboxylic anhydride, perylene tetracarboxylic imide compounds, naphthalene diimide-bithiophene copolymers, benzobisimidazobenzophenanthroline polymers, C 60 、C 70 、PCBM([6,6]-phenyl-C 61 -methyl butyrate) and other fullerene compounds, carbonyl bridge-bithiazole compounds, ALq3 (tris (8-hydroxyquinoline) aluminum), triphenylene bipyridine compounds, silole compounds, oxadiazole compounds, etc. In the present disclosure, among the materials used in the electron transport layer 15, organic n-type semiconductors are particularly preferred. In addition, the crystal type of these semiconductor materials is not limited, and can be appropriately selected according to the purpose. It can be single crystal, polycrystalline, or amorphous. In addition, the film thickness of the electron transport layer 15 is not particularly limited, and can be appropriately selected according to the purpose, but is preferably 5nm to 1000nm, and more preferably 10nm to 700nm.

[0127] There is no particular limitation on the method for forming the electron transport layer 15, and it can be appropriately selected according to the purpose. For example, a method for forming a thin film in a vacuum (vacuum film forming method), a wet film forming method, etc. can be listed. As the vacuum film forming method, sputtering method, pulse laser deposition (PLD) method, ion beam sputtering method, ion assisted method, ion plating method, vacuum evaporation method, atomic layer deposition (ALD) method, chemical vapor growth method (chemical vapor deposition (CVD) method), etc. can be listed. As a wet film forming method, a method of forming by coating a solvent in which an electron transport material is dissolved can be listed, or in the case of an oxide semiconductor, a sol-gel method can be listed. The sol-gel method is a method in which a solution is subjected to a chemical reaction such as hydrolysis, polymerization, condensation, etc. to make a gel, and then the densification is promoted by heat treatment. When using the sol-gel method, the method for applying the sol solution is not particularly limited and can be appropriately selected depending on the intended purpose. Examples include dip coating, spraying, wire bar coating, spin coating, roll coating, blade coating, and gravure coating. Wet printing methods include relief printing, offset printing, gravure printing, intaglio printing, rubber printing, and screen printing. The temperature during the heat treatment after applying the sol solution is preferably 80°C or higher, and more preferably 100°C or higher.

[0128] [Second electrode 16]

[0129] The second electrode 16 (which may be, for example, a back electrode) is a layer having a function of extracting electrons from the photoelectric conversion layer 14 via the electron transport layer. The second electrode 16 is a layer that functions as, for example, an anode (negative electrode).

[0130] The second electrode 16 can be formed directly on the electron transport layer (also called the electron injection layer) 15. The material of the second electrode 16 is not particularly limited; for example, the same material as 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 depending on the intended purpose. Examples of materials for the second electrode 16 include metals, carbon compounds, conductive metal oxides, and conductive polymers.

[0131] 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 antimony-doped tin oxide (ATO). Examples of the conductive polymer include polythiophene and polyaniline.

[0132] The material used in forming the second electrode 16 may be used alone, or two or more materials may be used in combination (mixed), or stacked. The second electrode 16 can be appropriately formed on the electron transport layer 15 by using a method such as coating, lamination, vacuum deposition, CVD, or lamination, depending on the type of material used or the type of the hole transport layer 13.

[0133] In addition, in the photoelectric conversion element of the present disclosure, it is preferred that at least one of the first electrode 12 and the second electrode 16 is substantially transparent. When using the photoelectric conversion element of the present disclosure, it is preferred to make the electrode transparent so that the incident light is incident from the electrode side. In such a case, it is preferred to use a light-reflecting material in the back electrode (the electrode on the opposite side to the transparent electrode, such as the second electrode), and glass, plastic, metal film, etc. on which a metal or conductive oxide is vapor-deposited can be preferably used. In addition, it is also effective to provide an anti-reflection layer on the electrode on the incident light side.

[0134] Furthermore, the structure of the photoelectric conversion element disclosed in the present invention is not limited to Figure 1 For example, the support 11 may be arranged in a Figure 1 The opposite side ( Figure 1The upper side of the second electrode 16 in the support 11), the second electrode 16, the electron transport layer 15, the photoelectric conversion layer 14, the hole transport layer 13, and the first electrode 12 can be stacked on the support 11 in the order described. In addition, for example, as described above, other components may or may not exist between the layers of the support 11, the first electrode 12, the hole transport layer 13, the photoelectric conversion layer 14, the electron transport layer 15 and the second electrode 16. In addition, an example in which the first electrode 12 is a transparent electrode and the second electrode 16 is a back electrode is described, but the photoelectric conversion element of the present disclosure is not limited to this. For example, in the photoelectric conversion element of the present disclosure, on the contrary, the first electrode may be a back electrode and the second electrode may be a transparent electrode.

[0135] [seal]

[0136] The photoelectric conversion element (e.g., solar cell) disclosed herein is preferably sealed to protect the device (photoelectric conversion element disclosed herein) from water or oxygen. The sealing structure is not particularly limited, and for example, it can be the same as that of a general photoelectric conversion element (e.g., solar cell). Specifically, for example, a sealing material can be applied only to the periphery of the photoelectric conversion element disclosed herein and covered with glass or a film, or a sealing material can be applied to the entire surface of the photoelectric conversion element disclosed herein and covered with glass or a film, or only a sealing material can be applied to the entire surface of the photoelectric conversion element disclosed herein.

[0137] The material of the sealing member is not particularly limited and can be appropriately selected depending on the intended purpose. For example, epoxy resin or acrylic resin is preferably used and cured. However, the sealing member may not be cured or may be partially cured.

[0138] The epoxy resin is not particularly limited, and examples thereof include: water dispersion system, solvent-free system, solid system, heat curing type, hardener mixed type, ultraviolet curing type, etc., among which heat curing type and ultraviolet curing type are preferred, and ultraviolet curing type is more preferred. In addition, even if it is an ultraviolet curing type, it can be heated, and preferably, it is heated even after ultraviolet 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, glycidyl ester type, etc. These can be used alone or in combination of two or more. In addition, it is preferred to mix a hardener or various additives in the epoxy resin as needed. Commercially available epoxy resin compositions can be used in the present disclosure. Among them, there are also commercially available epoxy resin compositions developed for use in solar cells or organic electroluminescence (EL) elements, which can be used particularly effectively in the present disclosure. Examples of commercially available epoxy resin compositions include TB3118, TB3114, TB3124, and TB3125F (manufactured by ThreeBond Co., Ltd.), WorldRock 5910, 5920, and 8723 (manufactured by Kyoritsu Chemical Industry Co., Ltd.), and WB90US(P) and WB90US-HV (manufactured by Moresco).

[0139] The acrylic resin is not particularly limited, and commercially available resins developed for solar cells or organic EL devices can be effectively used. Examples of commercially available acrylic resin compositions include TB3035B and TB3035C (manufactured by ThreeBond Co., Ltd.).

[0140] The hardener is not particularly limited and can be appropriately selected depending on the intended purpose. Examples include amine-based, acid anhydride-based, polyamide-based, and other hardeners. Examples of amine-based hardeners include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of acid anhydride-based hardeners include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic dianhydride, chlorendic anhydride, and dodecenylsuccinic anhydride. Examples of other hardeners include imidazoles and polythiols. These can be used alone or in combination of two or more.

[0141] As the additive, there is no particular limitation, can be suitably selected according to purpose, for example, can be enumerated: filler (filler), interstitial agent, polymerization initiator, desiccant (hygroscopic agent), hardening accelerator, coupling agent, flexible agent, colorant, flame retardant auxiliary, antioxidant, organic solvent etc..Wherein, preferably filler, interstitial agent, hardening accelerator, polymerization initiator, desiccant (hygroscopic agent), more preferably filler and polymerization initiator.By containing filler as additive, the intrusion of moisture or oxygen can be suppressed, and then the reduction of volume shrinkage during hardening, the reduction of outgassing amount during hardening or heating, the raising of mechanical strength, the control of thermal conductivity or fluidity etc. can be obtained.Therefore, comprising filler as additive is very effective in terms of maintaining stable output in various environments.

[0142] In addition, the output characteristics or durability of the photoelectric conversion element are not only affected by the intrusion of moisture or oxygen, but also the influence of outgassing generated during the hardening or heating of the sealing member cannot be ignored. In particular, the influence of outgassing generated during heating has a great influence on the output characteristics during storage in a high-temperature environment. By making the sealing member contain a filler or a gap agent or a desiccant, they themselves can inhibit the intrusion of moisture or oxygen. In addition, the amount of sealing member used can be reduced, thereby achieving the effect of reducing outgassing. Making the sealing member contain a filler or a gap agent or a desiccant is not only effective during hardening, but also effective when storing the photoelectric conversion element in a high-temperature environment.

[0143] The filler is not particularly limited and can be appropriately selected according to the purpose. Examples include inorganic fillers such as crystalline or amorphous silica, silicate minerals such as talc, aluminum oxide, aluminum nitride, silicon nitride, calcium silicate, and calcium carbonate. Among them, hydrotalcite is particularly preferred. These fillers may be used alone or in combination of two or more.

[0144] The average primary particle size of the filler is not particularly limited, but is preferably 0.1 μm to 10 μm, more preferably 1 μm to 5 μm. If the average primary particle size of the filler is within this preferred range, the effect of suppressing the intrusion of moisture or oxygen can be fully achieved, the viscosity becomes appropriate, the adhesion to the substrate and the degassing properties are improved, and the control of the width of the seal portion and workability are also effectively achieved.

[0145] The content of the filler is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less, relative to the entire sealing member (100 parts by mass). When the content of the filler is within the preferred range, the effect of inhibiting the intrusion of moisture or oxygen can be fully obtained, the viscosity becomes appropriate, and the adhesion and workability are also improved.

[0146] The gap agent is also called a gap control agent or a spacer. By including the gap agent as an additive, the gap of the sealing portion can be controlled. For example, when a sealing member is provided on the first substrate or the first electrode and a second substrate is placed thereon for sealing, the gap of the sealing portion can be easily controlled by mixing the gap agent with the sealing member so that the gap of the sealing portion is consistent with the size of the gap agent.

[0147] There is no particular limitation on the interstitial agent, and for example, it is preferably a granular agent with uniform particle size, high solvent resistance or heat resistance, and can be appropriately selected according to the purpose. As the interstitial agent, it is preferably an interstitial agent with high affinity for epoxy resin and spherical particle shape. Specifically, glass beads, silica particles, organic resin particles, etc. are preferred. These can be used alone or in combination of two or more. The particle size of the interstitial agent can be selected according to the gap of the sealing portion to be set, preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less.

[0148] The polymerization initiator is not particularly limited, and examples thereof include polymerization initiators that use heat or light to initiate polymerization. The polymerization initiator can be appropriately selected according to the purpose, and examples thereof include thermal polymerization initiators, photopolymerization initiators, and the like. Thermal polymerization initiators are compounds that generate active species such as free radicals or cations by heating, and examples thereof include azo compounds such as 2,2'-azobisisobutyronitrile (AIBN), or peroxides such as benzoyl peroxide (BPO). As thermal cationic polymerization initiators, benzenesulfonates or alkyl sulfonium salts can be used. In the case of epoxy resin, a photocationic polymerization initiator is preferably used. When a photocationic polymerization initiator is mixed with an epoxy resin and irradiated with light, the photocationic polymerization initiator decomposes to generate an acid, which causes polymerization of the epoxy resin, and the curing reaction proceeds. The photocationic polymerization initiator has the effects of less volume shrinkage during curing, no hindrance from oxygen, and high storage stability.

[0149] Examples of the photocationic polymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metallocene compounds, and silanol-aluminum complexes. Furthermore, as a polymerization initiator, a photoacid generator that generates an acid upon exposure to light may also be used. The photoacid generator acts as an acid that initiates cationic polymerization, and examples include onium salts such as ionic sulfonium salts or iodonium salts that contain a cationic portion and an anionic portion. These may be used alone or in combination of two or more.

[0150] The amount of the polymerization initiator added is not particularly limited and may vary depending on the material used. It is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to the entire sealing member (100 parts by mass). By adding an amount within the preferred range, curing can be appropriately performed, reducing the amount of uncured material remaining, and preventing excess outgassing.

[0151] The desiccant (also called a hygroscopic agent) is a material having the function of physically or chemically adsorbing and absorbing moisture. By making the sealing component contain the desiccant, the moisture resistance can be further improved and the influence of outgassing can be reduced. There is no particular limitation on the desiccant, and it can be appropriately selected according to the purpose, but it is preferably a granular desiccant, for example, inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolite. Among them, zeolite with a large moisture absorption capacity is preferred. These can be used alone or in combination of two or more.

[0152] The hardening accelerator (also known as a hardening catalyst) is a material that accelerates the hardening rate and is mainly used for thermosetting epoxy resins. The hardening accelerator is not particularly limited and can be appropriately selected according to the purpose. For example, tertiary amines or tertiary amine salts such as 1,8-diazabicyclo (5,4,0)-undecene-7 (1,8-diazabicyclo (5,4,0)-undecene-7, DBU) or 1,5-diazabicyclo (4,3,0)-nonene-5 (1,5-diazabicyclo (4,3,0)-nonene-5, DBN), imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole or 2-ethyl-4-methylimidazole, phosphines or phosphonium salts such as triphenylphosphine or tetraphenylphosphonium-tetraphenylborate, etc. These can be used alone or in combination of two or more.

[0153] The coupling agent is not particularly limited as long as it is a material that has the effect of increasing molecular bonding strength, and can be appropriately selected according to the purpose. Examples include silane coupling agents, etc. Specific 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.

[0154] In the present disclosure, a sheet-shaped adhesive agent can be used, for example. The sheet-shaped adhesive agent is, for example, an adhesive agent in which a resin layer is formed in advance on a sheet, and the sheet can use a film having high gas barrier properties or the like. In addition, the sheet can be formed only of a sealing resin. The sheet-shaped adhesive agent can also be attached to the sealing film. The sheet-shaped adhesive agent can also be attached to the sealing film after forming a structure provided with a hollow portion on the sealing film.

[0155] In the case of sealing using the sealing film, the sealing film is arranged so as to face the support body with the photoelectric conversion device interposed therebetween. The base material of the sealing film is not particularly limited in terms of shape, structure, size, or kind, and can be appropriately selected according to the purpose. The sealing film forms a barrier layer that prevents moisture or oxygen from passing through the surface of the base material, and can be formed on only one surface of the base material or on both surfaces.

[0156] The barrier layer can include, for example, a material in which a mixture formed of a metal oxide, a metal, a polymer, and a metal alkoxide is used as a main component. As the metal oxide, for example, alumina, silica, aluminum, or the like can be used, as the polymer, for example, polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, or the like can be used, and as the metal alkoxide, for example, tetraethoxysilane, triisopropoxyaluminum, 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, or the like can be used.

[0157] The barrier layer can be transparent or non-transparent. In addition, the barrier layer can be a single layer formed of a combination of the materials, or can be a multilayer structure. The barrier layer can be formed using a known method, and a vacuum film forming method such as sputtering, a dipping method, a roll coating method, a screen printing method, a spray method, a gravure printing method, or the like can be used.

[0158] [Lead wire]

[0159] In order to efficiently extract the current generated by light, the photoelectric conversion element (for example, a solar cell) of the present disclosure preferably has an electrode and a back electrode connection lead wire (lead wire). The lead wire is connected to the first electrode and the second electrode using, for example, a solder, a silver paste, or a conductive material such as graphite. The conductive material can be used alone, or two or more kinds can be mixed or used in a stacked structure. In addition, from the viewpoint of physical protection, the portion where the lead wire is mounted can be covered with an acrylic resin or an epoxy resin.

[0160] The lead wire is a general term for an electric wire for electrically connecting a power source or an electronic component or the like in a circuit, and for example, a plastic-covered wire, an enamel-covered wire, or the like can be used.

[0161] [Applications]

[0162] The use and method of use of the photoelectric conversion element of the present disclosure are not particularly limited, and for example, can be widely used for the same use as a general photoelectric conversion element (for example, a general solar cell). The photoelectric conversion element (for example, a solar cell) of the present disclosure can be applied to a power supply device, for example, by being combined with a circuit substrate or the like that controls the generated current. As a device category that utilizes the power supply device, for example, an electronic desktop computer, a solar-powered watch, or the like can be listed. In addition, the solar cell of the present disclosure can also be applied to a mobile phone, electronic paper, a hygrometer, or the like as a power supply device. In addition, by being combined with an auxiliary power supply or a secondary battery that is used to extend the continuous use time of an electric appliance of a chargeable or dry battery type, or the like, it can also be applied to nighttime use or the like. In addition, it can also be utilized as a self-supporting power supply that does not require battery replacement or a power supply wiring or the like.

[0163] Embodiment

[0164] Hereinafter, an embodiment of the present disclosure will be described. The present disclosure is not limited to the following embodiment.

[0165] [Embodiment 1]

[0166] The photoelectric conversion element of the present disclosure having the structure represented by the following formula was produced (manufactured) in the following manner. Figure 1

[0167] ​First, prepare an ITO glass substrate having an ITO electrode stacked on a glass substrate. The ITO glass substrate is a laminate of a substrate 11 and a first electrode 12, wherein the glass substrate is equivalent to the substrate 11, and the ITO electrode is equivalent to the first electrode 12. A dimethylformamide (DMF) solution containing a compound represented by the following chemical formula 3PATAT (0.1 mmol / L) and 4-phosphonobutyric acid (12 mmol / L) is placed on the surface of the ITO electrode (first electrode 12) side of the ITO glass substrate and applied using a spin coater (3,000 rpm, 30 seconds). Subsequently, the solution was dried by heating at 100°C on a hot plate for 10 minutes to form a monomolecular hole transport layer (hole transport layer 13) on the first electrode. Next, cesium iodide (0.738 g), formamidine iodide (7.512 g), methylamine bromide (0.905 g), lead iodide (25.17 g), and formamidine acetate (2.27 g) were dissolved in N,N-dimethylformamide (DMF, 40.0 mL) and dimethyl sulfoxide (DMSO, 12.0 mL), and the dissolved solution was spin-coated (3,000 rpm) on the hole transport layer 13 of the substrate. Then, the solution was heated at 150°C for 10 minutes to obtain a perovskite layer as the photoelectric conversion layer 14. Furthermore, a 1:1 mixed solution of 2-propanol and toluene (0.5 mg / mL) in which diethylenediamine diiodide was dissolved was spin-coated on the perovskite layer at 120°C for 10 minutes. Subsequently, a 20 nm C 60 (electron transport layer 15) and bathocuproine (BCP, 8 nm) (electron injection layer) were formed into films, and finally Ag (80 nm, second electrode 16) was formed into a film to obtain a photoelectric conversion element.

[0168] [3PATAT]

[0169]

[0170] In addition, the compound represented by the chemical formula 3PATAT was synthesized as follows.

[0171] <Synthesis Example of 3-PATAT>

[0172] First, the compound represented by the following chemical formula (IV) was synthesized in the following order. That is, first, hydroxyindole (10.7 g, 80.55 mmol) and phosphorus oxychloride (50 mL) were placed in a flask and heated and stirred at 100° C. for 14 hours under an argon atmosphere. The reaction solution after heating and stirring was cooled to room temperature and poured into ice water to stop the reaction. Then, it was neutralized with sodium hydroxide aqueous solution and the precipitate was filtered. The precipitate was refined by silica gel column chromatography (eluent: only dichloromethane) and then recrystallized using acetone to obtain 5.8 g (11.11 mmol, yield 41%) of light yellow crystalline compound (IV).

[0173] [Chemistry IV]

[0174]

[0175] The compound (IV) (1.73 g) and DMF (50 ml) were placed in a three-necked flask, and sodium hydride (360 mg) was slowly added at room temperature while stirring under an argon gas stream. Subsequently, diethyl (3-bromopropyl)phosphonate (2.9 mL) was added dropwise, and after the addition was completed, the mixture was heated and stirred at 70°C. After heating and stirring for 36 hours, the reaction solution was injected into water and the reaction was stopped, and extracted three times with dichloromethane. The extracted organic layer was dried over magnesium sulfate, and the solvent was distilled off. The obtained residue was generated by silica gel column chromatography (eluent: ethyl acetate / methanol = 1 / 0 to 1 / 1 (volume ratio)), and 2.17 g of the compound represented by the following chemical formula (V) was obtained. The yield was 49% based on the compound (IV) as the raw material.

[0176] [V]

[0177]

[0178] The compound (V) (200 mg) and dichloromethane (6 mL) were placed in a three-necked flask, and trimethylsilyl bromide (0.30 mL) was slowly added under a stream of argon while stirring at room temperature. After 14 hours, the reaction solution was concentrated under reduced pressure to obtain a solid residue. The crystals were repeatedly reprecipitated using a mixed solvent of dichloromethane and methanol (5 / 1, volume ratio), and washed with dichloromethane to obtain 125 mg of 3PATAT. The yield was 77% based on the compound (V) as a raw material. For the 3PATAT, the hydrogen nuclear magnetic resonance ( 1 H-Nuclear Magnetic Resonance, 1 HNMR), carbon nuclear magnetic resonance ( 13 CNMR), phosphorus nuclear magnetic resonance ( 31PNMR) and high-resolution mass spectrometry (HRMS) (matrix-assisted laser desorption / ionization (MALDI)). The following shows the results of these measurements. 1 HNMR, 13 CNMR and 31 PNMR, the graph is shown in Figures 2-4 .

[0179] 1 HNMR (400MHz, DMSO-d6): δ8.30-8.28(d,J=8.0Hz,3H),7.91-7.89(d,J=8.0Hz,3H),7.51-7.47(t,J=7.2 Hz,3H),7.41-7.37(t,J=7.6Hz,3H),5.08-5.05(t,J=6.8Hz,6H),1.95-1.85(m,6H),1.13-1.04(m,6H).

[0180] 13 CNMR (101MHz, DMSO-d6): δ141.0,137.8,123.2,122.5,121.5,120.4,111.4,103.2,46.8,46.6,25.2,23.8,23.0,22.9.

[0181] 31 PNMR (162MHz, DMSO-d6): δ24.75.

[0182] HRMS (MALDI) (m / z): [M] + C 33 H 36 Calculated value (calcd.for) for N3O9P3 is 711.1664; observed value (found) is 711.1653.

[0183] [Evaluation of Solar Cell Characteristics]

[0184] The photoelectric conversion characteristics of the photoelectric conversion element produced in Example 1 were measured using the method for measuring the output of silicon crystalline solar cell cells in accordance with Japanese Industrial Standards (JIS) C8913:1998. The results are shown in Table 1 below. A solar simulator (SMO-250III manufactured by Spectrometer Corporation) equipped with an air mass filter equivalent to AM 1.5G was used to adjust the power consumption to 100 mW / cm2 using a secondary reference Si solar cell. 2 The amount of light used as the light source for measurement was used, and while the test sample of the perovskite solar cell core (the sealed device made in Example 1) was irradiated with light, a source meter (Keithley Instruments Inc., 2400 general source meter) was used to measure the IV curve characteristics. Using the short-circuit current (Isc), open-circuit voltage (Voc) and fill factor (FF) obtained by the IV curve characteristics measurement based on the measurement, the short-circuit current density (Jsc) and the photoelectric conversion efficiency (PCE) were calculated based on the following formula 1 and the following formula 2. In addition, after continuous irradiation for 100 hours using a solar simulator combined with an air mass filter equivalent to AM 1.5G in a glove box, the photoelectric conversion efficiency was calculated in the same manner as described above.

[0185] Formula 1: Short-circuit current density (Jsc; mA / cm 2 )=Isc(mA) / effective light receiving surface S(cm 2 )

[0186] Formula 2: Photoelectric conversion efficiency (PCE; %) = Voc (V) × Jsc (mA / cm 2 )×FF×100 / 100(mW / cm 2 )

[0187] [Example 2]

[0188] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine formate (2.06 g). The results are shown in Table 1 below.

[0189] [Example 3]

[0190] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine thiocyanate (2.25 g). The results are shown in Table 1 below.

[0191] [Example 4]

[0192] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine chloride (1.76 g). The results are shown in Table 1 below.

[0193] [Example 5]

[0194] A photoelectric conversion element was prepared (manufactured) and evaluated in the same manner as in Example 1, except that the DMF solution containing the compound (I) (0.1 mmol / L) and 4-phosphonobutyric acid (12 mmol / L) was replaced with the compound (II) (0.1 mmol / L). The results are shown in Table 1 below.

[0195] [Example 6]

[0196] A photoelectric conversion element was prepared and evaluated in the same manner as in Example 1, except that the DMF solution containing the compound (I) (0.1 mmol / L) and 4-phosphonobutyric acid (12 mmol / L) was replaced with the compound (II) (0.1 mmol / L) and 3-aminopropylphosphonic acid. The results are shown in Table 1 below.

[0197] [Example 7]

[0198] A photoelectric conversion element was prepared and evaluated in the same manner as in Example 1, except that N,N-dimethylformamide (DMF, 40.0 mL) and dimethyl sulfoxide (DMSO, 12.0 mL) were replaced with N,N-dimethylformamide (DMF, 30.0 mL) and tetrahydrofurfuryl alcohol (22.0 mL). The results are shown in Table 1 below.

[0199] [Example 8]

[0200] A photoelectric conversion element was prepared and evaluated in the same manner as in Example 1, except that N,N-dimethylformamide (DMF, 40.0 mL) and dimethyl sulfoxide (DMSO, 12.0 mL) were replaced with N-methyl-2-pyrrolidone (NMP, 20.0 mL) and tetrahydrofurfuryl alcohol (32.0 mL). The results are shown in Table 1 below.

[0201] [Comparative Example 1]

[0202] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was not used. The results are shown in Table 1 below.

[0203] [Comparative Example 2]

[0204] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with methylamine chloride (1.47 g). The results are shown in Table 1 below.

[0205] [Comparative Example 3]

[0206] When forming the hole transport layer, the DMF solution containing the compound 3PATAT (one of the compounds represented by the chemical formula (I), 0.1 mmol / L) and 4-phosphonobutyric acid (12 mmol / L) in Example 1 was not used. Instead, poly (3,4-ethylenedioxythiophene:polystyrene sulfonic acid, PEDOT:PSS) (Heraeus, Clevios PVP.Al 4083) was spin-coated (3,000 rpm) on ITO and dried at 140°C for 20 minutes to form a hole transport layer. A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except for forming the hole transport layer. The results are shown in Table 1 below.

[0207] [Example 9]

[0208] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine fluoroacetate (2.66 g). The results are shown in Table 2 below.

[0209] [Example 10]

[0210] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with difluoroacetic acid formamidine (3.05 g). The results are shown in Table 2 below.

[0211] [Example 11]

[0212] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine trifluoroacetate (3.45 g). The results are shown in Table 2 below.

[0213] [Example 12]

[0214] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was used instead of formamidine cyanoacetate (2.82 g). The results are shown in Table 2 below.

[0215] [Example 13]

[0216] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine iodoacetate (5.01 g). The results are shown in Table 2 below.

[0217] [Example 14]

[0218] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine malonate (3.23 g). The results are shown in Table 2 below.

[0219] [Example 15]

[0220] A photoelectric conversion element was produced (manufactured) and evaluated in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with formamidine fluoromalonate (3.62 g). The results are shown in Table 2 below.

[0221] [Example 16]

[0222] A photoelectric conversion element was prepared (manufactured) in the same manner as in Example 1, except that formamidine acetate (2.27 g) was replaced with monoethyl malonate formamidine (3.84 g), and the photoelectric conversion efficiency was measured. The solar cell characteristics are shown in Table 2 below.

[0223] [Table 1]

[0224]

[0225] [Table 2]

[0226]

[0227] As can be seen from the differences between Examples 1 to 16 and Comparative Examples 1 and 2 in Tables 1 and 2, according to the present disclosure, it was confirmed that by using at least one of formamidine and its salts as an additive when forming a perovskite layer, a photoelectric conversion element with excellent characteristics can be obtained. In addition, according to the differences between Examples 1 to 16 and Comparative Example 3 in Tables 1 and 2, it was confirmed that by using a hole transport material (monomolecular hole transport compound) that forms a monomolecular film represented by Chemical Formula (I) in the hole transport layer and using at least one of formamidine and its salts as an additive when forming the perovskite layer, a photoelectric conversion element with excellent characteristics can be obtained.

[0228] The reason why a photoelectric conversion element with excellent characteristics can be obtained by not only using a monomolecular hole-transporting compound in the hole-transporting layer but also using a formamidine derivative when forming the perovskite layer is not clearly elucidated. For example, it is believed that since the perovskite layer is significantly affected by the substrate when forming the perovskite layer, combining these two elements (using a monomolecular hole-transporting compound in the hole-transporting layer and mixing a formamidine derivative when forming the perovskite layer) can achieve excellent characteristics.

[0229] As described above, this example confirmed that good solar cell characteristics can be obtained by using the structure of the photoelectric conversion element disclosed in the present invention.

[0230] The present disclosure has been described above using the embodiments and examples. However, the present disclosure is not limited to the embodiments and examples described above, and they can be arbitrarily and appropriately combined, modified, or selectively adopted as needed without departing from the scope of the present disclosure.

[0231] <Note>

[0232] A part or all of the above-mentioned embodiments and examples may be described as the following supplementary notes, but are not limited to the following contents.

[0233] (Note 1)

[0234] A photoelectric conversion element, characterized in that a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer and a second electrode are stacked in the order described,

[0235] The hole transport layer comprises a compound represented by the following chemical formula (I):

[0236] The photoelectric conversion layer includes a perovskite compound, and the perovskite compound is a perovskite compound formed from a raw material including at least one of formamidine and a salt thereof.

[0237] [ChemI]

[0238]

[0239] In the chemical formula (I),

[0240] Ar 1 is a structure containing an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms,

[0241] Ar 1 Can have except -L 1 -X 1 Substituents other than -L 1 -X 1 Substituents other than

[0242] -L 1 -X 1 It can be one or more. In the case of multiple, each L 1 and each X 1 They can be the same or different from each other.

[0243] Each L 1 To Ar 1 With X 1 The bonded atomic groups are either covalent bonds,

[0244] Each X 1 They are respectively groups capable of accepting and donating charges between the first electrode and the first electrode.

[0245] (Note 2)

[0246] The photoelectric conversion element according to Supplementary Note 1, wherein Ar in the chemical formula (I) 1 A nitrogen atom is included in the atoms constituting the aromatic ring.

[0247] (Note 3)

[0248] The photoelectric conversion element according to Supplementary Note 1 or 2, wherein L in the chemical formula (I) 1 To Ar 1 With X 1 The divalent linking group of the bond may be a single bond.

[0249] (Note 4)

[0250] The photoelectric conversion element according to any one of Supplementary Notes 1 to 3, wherein X in the chemical formula (I) 1 The group is a group capable of forming a chemical bond or a hydrogen bond with the first electrode.

[0251] (Note 5)

[0252] The photoelectric conversion element according to any one of Supplementary Notes 1 to 4, wherein X in the chemical formula (I) 1 Each is independently a dihydroxyphosphoryl group, a carboxyl group, a sulfonyl group, a boric acid group, a trihalosilyl group, a trialkoxysilyl group or a trihydroxysilyl group.

[0253] (Note 6)

[0254] The photoelectric conversion element according to any one of Supplementary Notes 1 to 5, wherein the compound represented by the chemical formula (I) has three or more substituents L 1 -X 1 .

[0255] (Note 7)

[0256] The photoelectric conversion element according to any one of Supplementary Notes 1 to 6, wherein in the chemical formula (I), -L 1 -X 1 The number of is in the range of 1 to 4.

[0257] (Note 8)

[0258] The photoelectric conversion element according to any one of Supplementary Notes 1 to 7, wherein in the chemical formula (I), each X 1 They are respectively phosphonic acid group (-P=O(OH)2), carboxyl group (-COOH), sulfonic acid group (-SO3H), boric acid group (-B(OH)2), trihalosilyl group (-SiX3, wherein X is a halide group) or trialkoxysilyl group (-Si(OR)3, wherein R is an alkyl group).

[0259] (Note 9)

[0260] The photoelectric conversion element according to any one of Supplementary Notes 1 to 8, wherein in the chemical formula (I), the Ar 1 It is represented by the following chemical formula (I-1).

[0261] [ChemI-1]

[0262]

[0263] In the chemical formula (I-1),

[0264] Ar 11 is an atomic group containing a cyclic structure, wherein the cyclic structure may be an aromatic ring or a non-aromatic ring, a monocyclic ring, a condensed ring, or a spirocyclic ring, and the atoms constituting the ring may or may not contain heteroatoms,

[0265] Ar 12 is an aromatic ring, and the atoms constituting the ring may or may not contain heteroatoms,

[0266] Ar 12 Can be used with Ar 11 Share more than one atom with Ar 11 Integration,

[0267] Ar 12 There may be one or more than one, and in the case of a plurality of them, they may be the same as or different from each other.

[0268] Ar 12 The number of is not particularly limited and can be, for example, in the range of 1 to 4.

[0269] (Note 10)

[0270] The photoelectric conversion element according to any one of the following Notes 1 to 9, wherein, in the formula (I-1), the Ar 11 is represented by any one of the following formulas (a1) to (a10).

[0271] [Chemicals a1-a10]

[0272]

[0273] (Note 11)

[0274] The photoelectric conversion element according to any one of the following Notes 1 to 10, wherein, in the formula (I-1), the Ar 12 is represented by the following formula (b), respectively.

[0275] [Chemical b]

[0276]

[0277] In the formula (b),

[0278] carbon atom C 1 and carbon atom C 2 serves as a part of atoms constituting the cyclic structure of the Ar 11 in the formula (I-1),

[0279] the R 1 is a hydrogen atom, X 1 in the formula (I), or a substituent, which can or can not include a hydrogen atom, at least one hydrogen atom in the substituent being replaced with X 1 in the formula (I),

[0280] the R 11 each can be the same as or different from each other, and is a hydrogen atom or a substituent, or, two R 11 adjacent to each other can be integrated with the benzene ring to which they are bonded to form a condensed ring,

[0281] the R 11 each can further have a substituent or can not have a substituent.

[0282] (Note 12)

[0283] The photoelectric conversion element according to Note 11, wherein the formula (b) is represented by any one of the following formulas (b1) to (b7).

[0284] [Chemicals b1-b7]

[0285]

[0286] In the chemical formulas (b1) to (b7), C 1 、C 2 and R 1 They are respectively the same as those in the chemical formula (b).

[0287] (Note 13)

[0288] The photoelectric conversion element according to any one of Supplementary Notes 1 to 12, wherein the compound represented by Chemical Formula (I) is a compound represented by any one of the following Chemical Formulas A-1 to A-23.

[0289] [Chemical A1A4]

[0290]

[0291] [Hua A5A8]

[0292]

[0293] [Hua9A12]

[0294]

[0295] [Hua A13A16]

[0296]

[0297] [Hua A17A20]

[0298]

[0299] [Hua A21A23]

[0300]

[0301] In the chemical formulas A-1 to A-23, each of the R 1 are respectively a hydrogen atom, X in the chemical formula (I) 1 or X in the chemical formula (I) 1 The further substituted substituents may be the same or different from each other, and each R 1 At least one of them is X in the chemical formula (I) 1 or X in the chemical formula (I) 1 further substituted substituents, said R 2 is a substituent, which may be one, multiple, or absent. In the case of multiple substituents, each R 2 They can be the same or different from each other.

[0302] (Note 14)

[0303] The photoelectric conversion element according to any one of Appendixes 1 to 13, wherein the compound represented by Chemical Formula (I) is a compound represented by the following Chemical Formula 4PATAT, 1-legged-3PATAT, 1-legged-3PATAT-H, 2-legged-3PATAT, 4PATTI-C3, 4PATTI-C4 or 3PATAT.

[0304] [Chemical 4PATAT]

[0305]

[0306] [Chemical 3PATAT1]

[0307]

[0308] [3PATATH]

[0309]

[0310] [Chemical 3PATAT2]

[0311]

[0312] [Chemical 4PATTI-C3]

[0313]

[0314] [Chemical 4PATTI-C4]

[0315]

[0316] [3PATAT]

[0317]

[0318] (Note 15)

[0319] The photoelectric conversion element according to any one of Notes 1 to 14 is characterized in that, in the perovskite compound contained in the photoelectric conversion layer, the salt of the formamidine contained in the raw material is at least one selected from the group consisting of formamidine formate, formamidine acetate, formamidine thiocyanate and formamidine chloride.

[0320] (Note 16)

[0321] The photoelectric conversion element according to any one of Supplementary Notes 1 to 15, wherein the perovskite compound contained in the photoelectric conversion layer is formed from a solution containing at least one of the formamidine and a salt thereof.

[0322] (Note 17)

[0323] The photoelectric conversion element according to any one of Supplementary Notes 1 to 16, wherein the hole transport layer contains a compound represented by the following Chemical Formula (II) in addition to the compound represented by the Chemical Formula (I).

[0324] A 1 -L 2 -X 2 (II)

[0325] In the chemical formula (II),

[0326] A 1 is an atomic group containing at least one substituent selected from the group consisting of an alkoxy group, a hydroxy group, a carboxyl group, a dihydroxyphosphoryl group, a dialkylphosphoryl group, a hydroxysulfonyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted aminocarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aminocarbonylamino group, an alkylcarbonylamino group, an alkylsulfonylamino group, an aminosulfonyl group, and a nitrogen-containing heterocyclic group,

[0327] Each L 2 To A 1 With X 2 The bonded atomic groups are either covalent bonds,

[0328] X 2 They are respectively groups capable of accepting and donating charges between the first electrode and the first electrode.

[0329] (Note 18)

[0330] The photoelectric conversion element according to Supplementary Note 17, wherein the A in the chemical formula (II) 1 In the above-mentioned formula (I), the substituted or unsubstituted amino group is at least one substituent selected from the group consisting of amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino and aminocarbonylamino.

[0331] (Note 19)

[0332] The photoelectric conversion element according to Supplementary Note 17 or 18, wherein the A in the chemical formula (II) 1 In the above-mentioned, the substituted or unsubstituted aminocarbonyl group is at least one of a monoalkylaminocarbonyl group and a dialkylaminocarbonyl group.

[0333] (Note 20)

[0334] The photoelectric conversion element according to any one of Supplementary Notes 17 to 19, wherein L in the chemical formula (II) 2 To A 1 With X 2The divalent linking group of the bond may be a single bond.

[0335] (Note 21)

[0336] The photoelectric conversion element according to any one of Supplementary Notes 17 to 20, wherein X in the chemical formula (II) 2 The group is a group capable of forming a chemical bond or a hydrogen bond with the first electrode.

[0337] (Note 22)

[0338] The photoelectric conversion element according to any one of Supplementary Notes 17 to 21, wherein the molar ratio of the compound represented by the chemical formula (I) to the compound represented by the chemical formula (II) is in the range of 1:100 to 1:1.

[0339] (Note 23)

[0340] The photoelectric conversion element according to any one of Supplementary Notes 17 to 22, wherein X in the chemical formula (II) 2 The alkyl silyl group is at least one selected from the group consisting of a dihydroxyphosphoryl group, a carboxyl group, a sulfonyl group, a boric acid group, a trihalogenated silyl group, a trialkoxysilyl group, and a trihydroxysilyl group.

[0341] (Note 24)

[0342] The photoelectric conversion element according to any one of Supplementary Notes 1 to 23, wherein the perovskite compound contained in the photoelectric conversion layer is an organic-inorganic perovskite compound.

[0343] (Note 25)

[0344] The photoelectric conversion element according to any one of Supplementary Notes 1 to 24, wherein the perovskite compound contained in the photoelectric conversion layer contains at least one of tin and lead.

[0345] (Note 26)

[0346] The photoelectric conversion element according to any one of Supplementary Notes 1 to 25, wherein the perovskite compound contained in the photoelectric conversion layer is a perovskite compound formed from a raw material containing a salt of formamidine,

[0347] The anion in the salt of formamidine contained in the raw material is a carboxylate anion.

[0348] (Note 27)

[0349] The photoelectric conversion element according to claim 26, wherein the carboxylate anion is a monoanion.

[0350] (Note 28)

[0351] The photoelectric conversion element according to any one of Supplementary Notes 1 to 27, which is a solar cell.

[0352] Industrial applicability

[0353] As described above, the present disclosure provides a photoelectric conversion element that can form a high-quality perovskite layer without using a poor solvent method and has excellent characteristics. The photoelectric conversion element disclosed herein can be effectively used as a solar cell, for example. The purpose and method of use of the photoelectric conversion element disclosed herein are not particularly limited, and for example, it can be applied to a wide range of fields with the same purpose and method of use as a general photoelectric conversion element (e.g., a general solar cell).

[0354] This application claims priority based on Japanese patent application No. 2023-034065, filed on March 6, 2023, the disclosure of which is incorporated herein in its entirety.

[0355] Explanation of Figure Numbers

[0356] 11: Substrate

[0357] 12: First electrode

[0358] 13: Hole transport layer

[0359] 14: Photoelectric conversion layer

[0360] 15: Electron transport layer

[0361] 16: Second electrode

Claims

1. A photoelectric conversion element, characterized in that: The first electrode, the electron transport layer, the photoelectric conversion layer, the hole transport layer and the second electrode are stacked in the order described, The hole transport layer comprises a compound represented by the following chemical formula (I): The photoelectric conversion layer includes a perovskite compound, and the perovskite compound is a perovskite compound formed from a raw material including at least one of formamidine and a salt thereof. [Chemical I] In the chemical formula (I), Ar 1 is a structure containing an aromatic ring, and the atoms constituting the aromatic ring may or may not contain heteroatoms, Ar 1 Can have except -L 1 -X 1 Substituents other than -L 1 -X 1 Substituents other than -L 1 -X 1 It can be one or more. In the case of multiple, each L 1 and each X 1 They can be the same or different from each other. Each L 1 To Ar 1 With X 1 The bonded atomic groups are either covalent bonds, Each X 1 They are respectively groups capable of accepting and donating charges between the first electrode and the first electrode.

2. The photoelectric conversion element according to claim 1, wherein Ar in the chemical formula (I) 1 A nitrogen atom is included in the atoms constituting the aromatic ring.

3. The photoelectric conversion element according to claim 1 or 2, wherein L in the chemical formula (I) 1 To Ar 1 With X 1 The divalent linking group of the bond may be a single bond.

4. The photoelectric conversion element according to any one of claims 1 to 3, wherein X in the chemical formula (I) 1 The group is a group capable of forming a chemical bond or a hydrogen bond with the first electrode.

5. The photoelectric conversion element according to any one of claims 1 to 4, wherein X in the chemical formula (I) 1 Each is independently a dihydroxyphosphoryl group, a carboxyl group, a sulfonyl group, a boric acid group, a trihalosilyl group, a trialkoxysilyl group or a trihydroxysilyl group.

6. The photoelectric conversion element according to any one of claims 1 to 5, wherein In the perovskite compound included in the photoelectric conversion layer, the formamidine salt included in the raw material is at least one selected from the group consisting of formamidine formate, formamidine acetate, formamidine thiocyanate, and formamidine chloride.

7. The photoelectric conversion element according to any one of claims 1 to 6, wherein The perovskite compound contained in the photoelectric conversion layer is formed from a solution containing at least one of the formamidine and a salt thereof.

8. The photoelectric conversion element according to any one of claims 1 to 7, wherein The hole transport layer contains a compound represented by the following chemical formula (II) in addition to the compound represented by the chemical formula (I). HAS 1 -L 2 -X 2 (II) In the chemical formula (II), A 1 is an atomic group containing at least one substituent selected from the group consisting of an alkoxy group, a hydroxy group, a carboxyl group, a dihydroxyphosphoryl group, a dialkylphosphoryl group, a hydroxysulfonyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted aminocarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aminocarbonylamino group, an alkylcarbonylamino group, an alkylsulfonylamino group, an aminosulfonyl group, and a nitrogen-containing heterocyclic group, Each L 2 To A 1 With X 2 The bonded atomic groups are either covalent bonds, X 2 They are respectively groups capable of accepting and donating charges between the first electrode and the first electrode.

9. The photoelectric conversion element according to claim 8, wherein In the chemical formula (II), the A 1 In the above-mentioned formula (I), the substituted or unsubstituted amino group is at least one substituent selected from the group consisting of amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino and aminocarbonylamino.

10. The photoelectric conversion element according to claim 8 or 9, wherein In the chemical formula (II), the A 1 In the above-mentioned, the substituted or unsubstituted aminocarbonyl group is at least one of a monoalkylaminocarbonyl group and a dialkylaminocarbonyl group.

11. The photoelectric conversion element according to any one of claims 8 to 10, wherein L in the chemical formula (II) 2 To A 1 With X 2 The divalent linking group of the bond may be a single bond.

12. The photoelectric conversion element according to any one of claims 8 to 11, wherein X in the chemical formula (II) 2 The group is a group capable of forming a chemical bond or a hydrogen bond with the first electrode.

13. The photoelectric conversion element according to any one of claims 8 to 12, wherein The molar ratio of the compound represented by the chemical formula (I) to the compound represented by the chemical formula (II) is in the range of 1:100 to 1:

1.

14. The photoelectric conversion element according to any one of claims 8 to 13, wherein X in the chemical formula (II) 2 The alkyl silyl group is at least one selected from the group consisting of a dihydroxyphosphoryl group, a carboxyl group, a sulfonyl group, a boric acid group, a trihalogenated silyl group, a trialkoxysilyl group, and a trihydroxysilyl group.

15. The photoelectric conversion element according to any one of claims 1 to 14, wherein The perovskite compound contained in the photoelectric conversion layer is an organic or inorganic perovskite compound.

16. The photoelectric conversion element according to any one of claims 1 to 15, wherein The perovskite compound included in the photoelectric conversion layer includes at least one of tin or lead.

17. The photoelectric conversion element according to any one of claims 1 to 16, wherein The perovskite compound contained in the photoelectric conversion layer is a perovskite compound formed from a raw material containing a salt of formamidine, The anion in the salt of formamidine contained in the raw material is a carboxylate anion.

18. The photoelectric conversion element according to claim 17, wherein The carboxylate anion is a monoanion. 19 . The photoelectric conversion element according to claim 1 , which is a solar cell.

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