Photoelectric conversion element and photoelectric conversion device

Abstract

To provide a photoelectric conversion element with improved conversion efficiency and durability.SOLUTION: The photoelectric conversion element has: a first electrode; a second electrode; and a photoelectric conversion layer containing a perovskite structure crystal and disposed between the first electrode and the second electrode. The photoelectric conversion element further has: a layer having crystals of a cyclic conjugated compound formed of multiple pyrrole rings boned to each other through conjugated bond between the photoelectric conversion layer and the first electrode; and an organic compound in the crystals of the cyclic conjugated compound formed of multiple pyrrole rings boned to each other through conjugated bond. Therein the organic compound has a pKa of 10.0 or more and a dipole moment of 1.60D or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Currently, np diode type silicon (Si) single crystal solar cells are widely used for photovoltaic power generation as solar cells with high energy conversion efficiency. However, these require high temperature processing and the materials themselves are expensive, so they have the problem of high cost per unit of power.

[0003] In order to solve these problems, solar cells using organic materials have been actively studied. Among them, perovskite solar cells using crystals with a perovskite structure as a photoelectric conversion layer have attracted attention due to their high photoelectric conversion efficiency. The perovskite crystals used in perovskite solar cells have a problem of low stability against heat, humidity, long-term light irradiation, etc., and it has been necessary to improve their durability. In Patent Document 1, a study is being conducted on the formation of a layer that protects the perovskite layer by incorporating a highly insulating polymer into the hole transport layer.

[0004] However, as a result of investigations by the present inventors, it was found that with such highly insulating materials, the photoelectric conversion significantly deteriorates when the film thickness is increased, and there are still problems in achieving both stable photoelectric conversion efficiency and durability. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6943591 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, forming a layer between the perovskite layer and the electrode for the purpose of protecting the perovskite layer is used as a means of solving the durability issue. However, adding these layers also poses the issue of preventing the movement of charges generated in the perovskite layer, which leads to a decrease in photoelectric conversion efficiency.

[0007] Therefore, an object of the present invention is to protect the perovskite structure from light, heat, and moisture, and to improve the durability and photoelectric conversion efficiency of a photoelectric conversion element and a photoelectric conversion device. [Means for solving the problem]

[0008] The present invention relates to a semiconductor device comprising a first electrode, a second electrode, A photoelectric conversion element having a photoelectric conversion layer including a crystal having a perovskite structure, the photoelectric conversion layer being disposed between the first electrode and the second electrode, a layer having a crystal of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings between the photoelectric conversion layer and the first electrode, and an organic compound is contained in the crystal of the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings; The organic compound is characterized by having a pKa of 10.0 or more and a dipole moment of 1.60 Debye (D) or more. Effect of the Invention

[0009] According to the present invention, it is possible to provide a photoelectric conversion element having improved conversion efficiency and durability. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view in a thickness direction of a first embodiment of a photoelectric conversion element of the present invention. [Diagram 2] FIG. 4 is a schematic cross-sectional view in the thickness direction of a second embodiment of a photoelectric conversion element of the present invention. [Diagram 3] 1 is a perspective view showing a schematic diagram of an embodiment of a moving body including a photoelectric conversion element of the present invention; [Figure 4]FIG. 1 is a perspective view showing a schematic diagram of one embodiment of a building material including a photoelectric conversion element of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below with reference to preferred embodiments. The present invention is not limited to the following embodiments, and the scope of the present invention also includes modifications and improvements to the following embodiments based on the ordinary knowledge of those skilled in the art, provided that the modifications and improvements do not deviate from the spirit of the present invention. In this specification, the term "layer" refers not only to a layer having a clear boundary or a flat thin-film layer, but also to a layer having a concentration gradient in which the contained elements change gradually, or to a layer that can form a complex structure together with other layers. Elemental analysis of the layer can be performed, for example, by performing TOF-SIMS / FE-TEM / EDS line analysis measurement of the cross section of the photoelectric conversion element to confirm the element distribution of a specific element.

[0012] The present invention relates to a photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer containing a crystal of a perovskite structure disposed between the first electrode and the second electrode, the photoelectric conversion element having the photoelectric conversion layer, characterized in that a layer having a crystal of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings is provided between the photoelectric conversion layer and the first electrode, the crystal of the cyclic conjugated compound formed by conjugating the plurality of pyrrole rings contains an organic compound, and the organic compound has a pKa of 10.0 or more and a dipole moment of 1.60 Debye or more.

[0013] The present inventors have found that the above-mentioned characteristics make it possible to improve the photoelectric conversion efficiency and durability. The present inventors consider these effects as follows. Compounds having a crystal of a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated have high hole transport properties. Therefore, by combining a layer containing these compounds with a perovskite layer, it becomes possible to quickly transport the charge generated in the perovskite layer. When an organic compound having a pKa of 10.0 or more and a dipole moment of 1.60 Debye (D) or more is contained in the crystal, such an effect is more pronounced. When the pKa is 10.0 or more, if an organic compound having a dipole moment of 1.60D or more is close to the cyclic conjugated compound, it is expected to interact with the π electrons of the cyclic conjugated compound and cause charge imbalance. As a result, polarization is promoted, and it is considered that the mobility of the charge is improved. When the dipole moment of an organic compound is high, the molecule is easily polarized and charge imbalance is easily generated. Furthermore, when the pKa is high, it is considered that the basicity is high and it is easier to increase the charge imbalance. The organic compound in the crystal of the cyclic conjugated compound of the present invention is characterized in that it has a pKa of 10.0 or more, and preferably has a pKa of 10.0 or more and 40.0 or less.

[0014] The dipole moment of the organic compound is characterized by being 1.60 D or more, and preferably 2.20 D or more. When it is within these ranges, the above-mentioned effects are easily manifested, and photoelectric conversion efficiency and durability are easily improved. From the viewpoint of ease of incorporation into the crystal, the organic compound is characterized by having a molar volume of 20.0 cm. 3 / mol or more 85.0cm 3 / mol or less. 3 When the amount is less than or equal to 1 / mol, the photoelectric conversion efficiency is easily improved since the photoelectric conversion efficiency can be improved without significantly destroying the crystal structure.

[0015] As the organic compound, various organic compounds such as amides, esters, ketones, alcohols, glycerols, sulfoxides, and organic amines can be used, among which amides and sulfoxides are preferred, and further preferably any one selected from the group consisting of N-methylformamide, N-ethylformamide, N-propylformamide, and dimethylsulfoxide. When these organic compounds are contained in the crystal, the photoelectric conversion efficiency is easily improved. These organic compounds are preferably contained in an amount of 0.50% by mass or more and 2.00% by mass or less with respect to the cyclic conjugated compound in which the multiple pyrrole rings are conjugated. When the amount is 0.50% by mass or more, the above-mentioned effects are easily manifested and the photoelectric conversion efficiency is easily improved. Also, when the amount is 2.00% by mass or less, the crystallinity is easily maintained, so that the photoelectric conversion efficiency and durability are easily improved. The method of introducing the organic compound into the crystal is not particularly limited, but for example, there is a method of making the organic compound coexist during the crystallization process. The amount of the organic compound in the crystals can be changed by changing various conditions such as the treatment time and treatment intensity in the crystallization step (e.g., step 3 described below). For example, the amount of the organic compound can be reduced by lengthening the treatment time after appropriately setting the treatment intensity.

[0016] The organic compound of the present invention is contained in a crystal. The organic compound contained in the crystal can be identified and quantified by the following method. Dispersing the cyclic conjugated compound of the present invention in a heavy solvent in which the compound is insoluble; 1 The organic compound of the present invention is quantified by measuring H-NMR. Next, the cyclic conjugated compound of the present invention is dissolved in a heavy solvent in which it can be dissolved, and the type and amount of the organic compound present in the crystal can be identified and quantified by taking the difference from the quantified value.

[0017] The cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings used in the present invention is preferably a porphyrin compound or a phthalocyanine compound from the viewpoint of the spread of the π electron cloud that is the starting point of the interaction, and more preferably a phthalocyanine compound. The phthalocyanine compound preferably has a central element, and examples of the central element include Ga, Cu, Ti, Zn, Si, V, Pb, and Pt. From the viewpoint of the transport performance of holes, Ga, Ti, and Zn are preferred, and Ga is more preferred. The cyclic conjugated compound formed by covalently bonding pyrrole rings may have an axial ligand as a ligand. From the viewpoint of the spread of the π electron cloud and the ease of crystallization, OH, Cl, and O are preferred as the axial ligand. Furthermore, as a combination of these central metals and axial ligands, a hydroxygallium phthalocyanine compound is more preferred.

[0018] Specific examples of the cyclic conjugated compound of the present invention in which a plurality of pyrrole rings are covalently bonded are given below. [ka] [ka] In the above formulas (P-1) and (P-2), R1 to R 12 each independently represents an organic group containing hydrogen, an aromatic group which may have a substituent, or an aliphatic group which may have a substituent.

[0019] R1~R 12As the X, hydrogen, methyl group, ethyl group, propyl group, isopropyl group, butyl group, octyloxy group, butoxy group, halogen atom, phenyl group, phenoxy group, carboxyphenyl group, benzenesulfonic acid group, hydroxyphenyl group, dihydroxyphenyl group, trihydroxyphenyl group, methoxyphenyl group, dimethoxyphenyl group, trimethoxyphenyl group, methylphenyl group, dimethylphenyl group, trimethylphenyl group, pyridyl group, aminophenyl group, sodium sulfonate base, 4-cumylphenoxy group, sulfonic acid group, phenylthio group, tert-butyl group, hydroxy group, carbonyl group, methoxy group, amino group, sulfo group, and aldehyde group are preferable. In the above formulas (P-1) and (P-2), X represents a metal atom or an inorganic compound, and specifically, SiCl2, Cu, Zn, Pd, Pb, Ni, Pt, Co, MnCl, FeCl, VO, and RuCO are preferable.

[0020] Specific examples of the phthalocyanine compound of the present invention are given below. [ka] [ka] [ka]

[0021] In the above formulas (P-3) and (P-4), R 13 ~R 28 R each independently represents an organic group containing a hydrogen atom, an aromatic group which may have a substituent, or an aliphatic group which may have a substituent. 13 ~R 28Examples of the aryl group include hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, octyloxy group, butoxy group, halogen atom, phenyl group, phenoxy group, carboxyphenyl group, benzenesulfonic acid group, hydroxyphenyl group, dihydroxyphenyl group, trihydroxyphenyl group, methoxyphenyl group, dimethoxyphenyl group, trimethoxyphenyl group, methylphenyl group, dimethylphenyl group, trimethylphenyl group, pyridyl group, aminophenyl group, sodium sulfonate base, 4-cumylphenoxy group, sulfonic acid group, phenylthio group, tert-butyl group, hydroxy group, carbonyl group, methoxy group, amino group, sulfo group, and aldehyde group. Among them, methyl group, ethyl group, propyl group, butyl group, halogen atom, sulfonic acid group, hydroxy group, carbonyl group, methoxy group, amino group, sulfo group, and aldehyde group are preferred. In the above formulas (P-3), (P-4), and (P-5), X represents a metal atom or an inorganic compound, and specifically, SiCl2, Cu, Zn, Pd, Pb, Ni, Pt, Co, MnCl, FeCl, VO, and RuCO are preferable.

[0022] It was found that even when a hole transport layer or an insulating layer is introduced to a thickness of several tens of nm between the layer having the crystal of the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings according to the present invention and the photoelectric conversion layer, it contributes to improving the leakage resistance and conversion efficiency. It is particularly preferable from the viewpoint of leakage resistance that the layer having the crystal of the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings according to the present invention is in contact with the photoelectric conversion layer as a charge transport layer or as a part of the charge transport layer. Specific examples of compounds used in the hole transport layer or insulating layer that may be inserted between the layer having the crystal of the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings according to the present invention and the photoelectric conversion layer include sodium chloride, sodium iodide, potassium iodide, rubidium iodide, cesium acetate, copper bromide (1), copper iodide (1), nickel chloride (2), zinc iodide, germanium dioxide, aluminum acetylacetonate, europium (3) acetylacetonate, 1,8-diaminooctane, Dihydroiodide, 1,4-butanediamine dihydroiodide, hexylamine hydrobromide, n-octylamine hydrobromide, 2-phenylethylammonium iodide, ethylenediamine Hydrogen diiodide, sodium fluoride, cesium chloride, methylammonium chloride, lead thiocyanate(2), lead acetate(2), potassium chloride, niobium fluoride(5), choline chloride, L-α-phosphatidylcholine, fullerene, phenyl C61 butyric acid methyl ester (PCBM((6,6)-phenyl C61 butyric acid methyl ester)), iodopentafluorobenzene, F4TCNQ, thiophene, pyridine, pentafluorobenzyl bromide, (3-mercaptopropyl) Preferred examples include trimethoxysilane, thiourea, benzylamine, hexamethylenetetramine, N-(3-aminopropyl)-2-pyrrolidinone, theophylline, caffeine, 2-aminoethanesulfonamide hydrochloride, tri-n-octylphosphine oxide, graphene oxide, poly(3-hexylthiophene-2,5-diyl), poly(4-vinylpyridine), polyethylene oxide, polyvinylpyrrolidone, and poly(methyl methacrylate). Among these, sodium chloride, potassium iodide, rubidium iodide, cesium acetate, nickel(2) chloride, aluminum acetylacetonate, n-octylamine hydrobromide, 2-phenylethylammonium iodide, sodium fluoride, cesium chloride, methylammonium chloride, potassium chloride, niobium(5) fluoride, thiophene, pyridine, trimethoxysilane, thiourea, benzylamine, theophylline, poly(4-vinylpyridine), and poly(methyl methacrylate) are particularly preferred.

[0023] In addition, when the layer having the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings contains a resin, it is preferable that P / B is 1 or more and 20 or less, where B is the content of the resin in the layer and P is the content of the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings.

[0024] 1 is a cross-sectional view showing a schematic configuration of one embodiment of the photoelectric conversion element of the present invention. The case where the layer having a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings according to the present invention is a charge transport layer will be described below. A second electrode 3, an electron transport layer 4, a photoelectric conversion layer 5, a charge transport layer 6, and a first electrode 7 are provided on a substrate 2. One of the first electrode 7 and the second electrode 3 is a positive electrode and the other is a negative electrode, and a current can be extracted by connecting the first electrode 7 and the second electrode 3 to an external circuit. The photoelectric conversion layer 5 is excited by light incident through the substrate 2, the second electrode 3, and the electron transport layer 4, or the first electrode 7 and the charge transport layer 6, and generates electrons or holes. That is, the photoelectric conversion layer 5 generates a current between the first electrode 7 and the second electrode 3. The electron transport layer 4 is a layer disposed between the photoelectric conversion layer 5 and the two electrodes 3 and 7, and may not be formed in some cases. A form in which a plurality of electron transport layers 4 and photoelectric conversion layers 5 are stacked may be used. Such a form may be called a tandem structure. In addition, as shown in FIG. 2, a photoelectric conversion element may be fabricated on the substrate 2 in the order of the first electrode 7, the charge transport layer 6, the photoelectric conversion layer 5, the electron transport layer 4, and the second electrode 3.

[0025] Each member constituting the photoelectric conversion element of the present invention will be described below. [Photoelectric conversion element] The photoelectric conversion element of the present invention is a photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer containing a crystal of a perovskite structure disposed between the first electrode and the second electrode, characterized in that a charge transport layer is provided between the photoelectric conversion layer and the first electrode. In addition, in order to improve the photoelectric conversion efficiency, the photoelectric conversion elements may be stacked in a tandem type. The photoelectric conversion elements to be stacked are not limited to the type of photoelectric conversion element, and may include a perovskite solar cell using a crystal of a perovskite structure in the photoelectric conversion layer, a silicon solar cell, a CIGS solar cell, and the like. The photoelectric conversion layer of the photoelectric conversion element of the present invention and each layer including the charge transport layer can be formed by coating or vapor deposition. Examples of the coating method include dip coating, spin coating, spray coating, inkjet coating, meniscus coating, screen coating, roll coating, die coating, blade coating, curtain coating, and wire bar coating. The coating method is a method in which the coating liquid for each layer described later is prepared, coated in the desired layer order, and dried. A desired method can be selected from these film formation methods according to each layer.

[0026] Each layer will be described below. 〔substrate〕 The photoelectric conversion element 1 of the present invention may include a substrate 2, examples of which include a transparent glass substrate such as soda-lime glass or alkali-free glass, a ceramic substrate, and a transparent plastic substrate. When light is taken in from the first electrode 7 side, an opaque material can be used for the substrate 2, and when light is taken in from the second electrode 3 side, the substrate 2 is made of a transparent material.

[0027] 〔electrode〕 The material of the first electrode 7 and the second electrode 3 is not particularly limited, and a conventionally known material can be used. For example, metals such as gold, silver, titanium, and copper, sodium, sodium-potassium alloy, lithium, magnesium, carbon, carbon nanotubes, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al2O3 mixture, and Al / LiF mixture can be mentioned. Examples of transparent electrode materials include conductive transparent materials such as CuI, ITO (indium tin oxide), SnO2, AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), FTO (fluorine-doped tin oxide), and ATO (antimony-doped tin oxide), and conductive transparent polymers. These materials may be used alone, or two or more of them may be used in combination. At least one of the electrodes on the light incident side of the first electrode 7 and the second electrode 3 may be a transparent electrode, and the other may be a transparent electrode or a transparent electrode that also serves as a reflective layer formed of a light-reflective material, or a transparent electrode provided with a reflective layer on the side opposite to the light incident side. When the first electrode 7 is on the light incident side, the second electrode 3 may be a transparent electrode and the substrate 2 may be a reflective layer. The transparent electrode may be a patterned electrode.

[0028] [Photoelectric Conversion Layer] The photoelectric conversion layer 5 has a crystal having a perovskite structure. The crystal having a perovskite structure used in the present invention is preferably represented by the following general formula [1]. ABX3 [1] In the above general formula [1], A is a monovalent cation of an organic molecule or a metal atom, B is a divalent metal cation, and X is a monovalent halide anion. In the general formula [1], A is preferably represented by, for example, CpNqHr (where p, q, and r are all positive integers) in the case of an organic molecule. Specific examples include methylammonium and formamidium. The metal atom is not particularly limited, but lithium, cesium, sodium, potassium, and rubidium are preferred. These organic molecules or metal atoms may be used alone or in combination of two or more. When the constituent A cations are too large to fit within the 3D perovskite crystal, they form 2D perovskite crystals, 2.5D perovskite crystals with both 2D and 3D properties, bilayer crystals of 3D and 2D perovskite structures, or mixed 3D and 2D perovskite crystals, all of which function as photoelectric conversion layers. A bilayer crystal of 3D and 2D perovskite refers to a crystal in which 3D and 2D perovskite crystals are stacked as independent, separate layers, while a mixed 3D and 2D perovskite refers to a crystal with a structure in which both regions or domains of 2D or 2.5D layered and 3D perovskite crystals are mixed.

[0029] The crystals having a two-dimensional perovskite or 2.5-dimensional perovskite structure are preferably represented by the following general formulas [2] to [4], where n is a positive integer. R'2A n-1 B n X 3n+1 [2] R''A n-1 B n X 3n+1 [3] R'''2A n B n X 3n+1 [4]

[0030] In the above general formulas, [2] forms an RP (Ruddlesden-Popper) type perovskite structure, [3] forms a DJ (Dion-Jacobson) type perovskite structure, and [4] forms an ACI (Alternating cations in the interlayer) type perovskite structure.

[0031] R', R'', and R''' in the above general formulas [2] to [4] are organic molecules or metal cations which may have a substituent, and specific examples thereof include ethylammonium, propylammonium, n-butylammonium, n-hexylammonium, n-octylammonium, 1,6-hexadiammonium, iso-butylammonium, 3-(nonafluoro-tert-butyloxy)propylamine, 1,3-propanediammonium, 1,5-pentamethylenediamine, octyldiammonium, 2,2-(ethylenedioxy)bis(ethylammonium), 5-aminovaleric acid, 4-tert-butylammonium, N,N'-dimethylethylene-1,2-diammonium, 2,2,3,3,3-pentafluoropropylammonium, guanidinium, propylammonium, propargylamine, alkylammonium, cyclohexylmethylammonium, 4-(aminomethyl)piperidinium, piperidinium, pyrrolidinium, cyclohexylmethylammonium, 4-(aminomethyl)piperidinium, piperidinium, pyrrolidinium, cyclohexylmethylammonium, 4-aminomethyl)piperidin ... Cylammonium, 4-fluorophenethylammonium, 4-fluorophenethylammonium, trifluoromethylbenzylammonium, pentafluorobenzylammonium, pentafluorophenylethylammonium, 4-methoxyphenethylammonium, imidazolium, pyridinium, 3-thiophenemethylammonium, 2-thiopheneethylammonium, 2-thiopheneformamidium, 2-thiophenemethylammonium, 1-naphthylmethylammonium, 2-naphthylmethylammonium, phenethylammonium, phenylammonium, benzylammonium, 2,5-thiophenedimethylammonium, phenylpropylammonium, 1,4-phenylenedimethanamine, 3-phenyl-2-propene-1-ammonium, phenylbutylammonium, 4-tert-butyl-benzylammonium, 3-(aminomethyl)piperidinium, 4-(aminomethyl)piperidinium are preferred.

[0032] In the above general formulas [1] to [4], B is a metal atom, such as lead, tin, bismuth, zinc, titanium, antimony, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium. Among these, lead, tin, and bismuth are preferred from the viewpoint of electron orbital overlap. These metal atoms may be used alone or in combination of two or more.

[0033] X in the above general formulas [1] to [4] is a halogen atom, such as chlorine, bromine, and iodine. These halogen atoms may be used alone or in combination of two or more. Among them, halogen atoms are preferred because the perovskite crystals are easily soluble in organic solvents by containing halogen in the structure, making it possible to apply the perovskite crystals to inexpensive printing methods. Furthermore, iodine is more preferred because the energy band gap of the perovskite crystals is narrowed.

[0034] Specifically, 3D perovskites, 2D perovskites, and mixed 3D / 2D perovskites are MAPbI3 and FAPbCl 3、 FAPbI3, MAPbI x Br 3-x、 MAPbI x Cl 3-x , Cs 0.05 (MA 0.17 FA 0.83 ) 0.95 Pb(I 0.83 Br 0.17 )3, {Cs x1 (FAx2MA 1-x2 ) 1-x1} x3 Pb(I x4 Br 1-x4 ) x5 , Cs 0.05 FA 0.88 MA 0.07 PbI 2.56 Br 0.44 , (FAPbI3) 0.95 (MAPbBr3) 0.05 , (FAPbI3) 0.85(MAPbBr3) 0.15 、CsPbI3、CsPbBr3、Cs x (MA) 1-x PbI3、Cs x (FA) 1-x PbI 3, MA x (FA) 1-x PbI3、MA 0.17 FA 0.83 Pb(I 0.83 Br 0.17 )3、Cs 0.15 FA 0.85 PbI 2.55 Br 0.45 、Cs 0.05 FA 0.88 MA 0.07 PbI 2.56 Br 0.44 、Cs 0.15 FA 0.85 PbI 2.55 Br 0.45 、(AND)2(MA)2Pb3I 10 、(PTA)2(MA)4Pb5I 16 、(AND)2(MA)4Pb5I 16 、(ThMA)2(MA)2Pb3I 10, (3BBA)2(MA)2Pb3I 10 、(ThMA)2(FA)4Pb5I 16 、(4FPEA)2(FA 0.3 MA 0.7 )4Pb5I 16 、(PDMA)FA2Pb3I 10 、(3AMPY)(MA)3Pb4I 13 、(PDMA)MA5Pb6I 19 、(PDMA)MA3Pb4I 13 、(TTDMA)MA3Pb4I 13 、(TTDMA)MA4Pb5I 16 ,(THAT 0.9 AND 0.1 )2MA4Pb5I 16 ,(THAT 0.9 AND 0.1 )2MA3Pb4I 13 、(4FPEA)2MA3Pb4I 13 、(4FPEA)2MA4Pb5I 16, (BA)2MA2Pb3I 10 , (BA)2MA3Pb4I 13 , (TEA)2MA2Pb3I 10 , (BA)2MA4Pb5I 16 , (BA)2MA3Pb4I 13、 CsSnBr3, CsSnI3, FA 0.75 MA 0.25 Sn 0.95 Ge 0.05 I3, FAMASnGeI3, FASnBr3, FASnI3, MA2Sn3I8, MASnBr3, MASnGeI3, and MASnI3 are preferred. The A site, B site, and X site in the above general formula may be adjusted to be under- or over-adjusted depending on the purpose, and the combination of x1 to x5 may be changed depending on the purpose. The combination of x1 to x5 is, for example, as shown in Table 1. Particularly preferred ranges are 0.03≦x1≦0.10, 0.80≦x2≦0.96, 0.95≦x3≦1.05, 0.80≦x4≦0.96, and 2.95≦x5≦3.05. MACl may be included as a material for forming perovskite crystals.

[0035] [Table 1]

[0036] In the above specific examples, "MA" stands for methylammonium, "FA" stands for formamidinium, "PEA" stands for phenethylammonium, "PTA" stands for phenyltriethylammonium, "ThMA" stands for 2-thiophenemethylammonium, "3BBA" stands for 3-bromobenzylammonium, "3AMPY" stands for 3-(aminomethyl)pyridine, "PDMA" stands for 1,4-phenylenedimethaneammonium, "TTDMA" stands for thieno[3,2-b]thiophene-2.5-diyldimethaneammonium, "4FPEA" stands for 4-fluorophenethylammonium, "BA" stands for butylammonium, and "TEA" stands for 2-thiophenethylammonium.

[0037] The crystal with the perovskite structure preferably has a cubic structure in which a metal atom B is located at the body center, an organic molecule A at each vertex, and a halogen atom or X at the face center. Although the details are not clear, it is presumed that the presence of such a structure makes it easy to change the orientation of the octahedron in the crystal lattice, thereby increasing the mobility of electrons in the crystal with the perovskite structure and improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0038] The perovskite crystal used in the present invention is preferably a crystalline semiconductor. The crystalline semiconductor means a semiconductor in which the scattering peak can be detected by measuring the X-ray scattering intensity distribution. By using the perovskite crystal as a crystalline semiconductor, the mobility of electrons in the perovskite crystal is increased, and the photoelectric conversion efficiency of the photoelectric conversion element is improved.

[0039] The thickness of the photoelectric conversion layer according to the present invention is preferably 5 nm or more and 2000 nm or less. If the thickness is 5 nm or more, light can be sufficiently absorbed, and if the thickness is 2000 nm or less, the generated charge can be transported to each electrode. The more preferred lower limit is 50 nm, the more preferred upper limit is 1200 nm, the even more preferred lower limit is 100 nm, and the even more preferred upper limit is 1000 nm.

[0040] [Charge transport layer] The present invention is a photoelectric conversion element having a charge transport layer, and the layer having the crystal of the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings according to the present invention is the charge transport layer. In this case, the thickness of the charge transport layer is preferably 1 nm or more and 1000 nm or less, more preferably 5 nm or more and 500 nm or less, and particularly preferably 10 nm or more and 200 nm or less. As described above, when the charge transport layer contains a resin, the photoelectric conversion efficiency and durability are easily improved. In the present invention, the resin refers to a molecule having a number average molecular weight (Mn) of 1000 or more. The preferred number average molecular weight of the resin is 10000 or more. The resin preferably has a glass transition temperature (Tg), and the Tg of the resin is preferably 95° C. or lower. Resins preferably used in the present invention include polyester resins, polycarbonate resins, polyvinyl acetal resins, polyvinyl butyral resins, acrylic resins, polyvinyl alcohol resins, cellulose resins, polystyrene resins, polyvinyl acetate resins, polyvinyl chloride resins, etc. The amount of the resin is preferably 1.0% by mass or more and 20% by mass or less with respect to the cyclic conjugated compound. The charge transport layer can be formed by preparing a coating solution for the charge transport layer containing the above-mentioned materials and solvent, forming this coating film on the photoelectric conversion layer, and drying it. Examples of the solvent used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, alcohol-based solvents or aromatic hydrocarbon-based solvents are preferred.

[0041] [Second Charge Transport Layer] In the present invention, from the viewpoint of film compatibility of the charge transport layer 6, a second charge transport layer may be further provided between the charge transport layer 6 and the first electrode . The material of the second charge transport layer is not particularly limited, and examples thereof include spirofluorene compounds, triphenylamine compounds, chrysene compounds, pyrene compounds, phthalocyanine compounds, carbazole compounds, fluorene compounds, phenylcyclohexane compounds, benzidine compounds, phenoxazine compounds, phenylenediamine compounds, thiocyanate compounds, and thiophene compounds. In particular, from the viewpoint of compatibility with the film interface, it is preferable that the compound has an aromatic ring, and Spiro-OMeTAD, PTAA, and phthalocyanine compounds are preferable. The second charge transport layer may have a dopant as an additive to improve the charge transport ability. Examples of materials that can be used as a dopant include lithium compounds such as bis(trifluoromethanesulfonyl)imide lithium, cobalt compounds such as [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(3)tris(bis(trifluoromethylsulfonyl)imide)], boron compounds such as tetrakis(pentafluorophenyl)borate, molybdenum compounds such as tris[1-(methoxycarbonyl)-2-(trifluoromethyl)-ethane-1,2-dithiolene]molybdenum, organic compounds having a tetracyanoquinodimethane skeleton such as 2,3,4,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, and organic compounds having a pyridine skeleton such as 4-tert-butylpyridine.

[0042] [Electron transport layer] In the photoelectric conversion element of the present invention, as shown in FIGS. 1 and 2, an electron transport layer 4 may be disposed between the second electrode 3 and the photoelectric conversion layer 5. The material of the electron transport layer 4 is not particularly limited, and examples thereof include N-type conductive polymers, N-type low-molecular-weight organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surfactants, and the like. Specific examples thereof include cyano group-containing polyphenylene vinylene, boron-containing polymers, bathocuproine, bathophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalene tetracarboxylic acid compounds, fullerene compounds, perylene compounds, phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, and zinc sulfide. The thickness of the electron transport layer 4 is preferably 1 nm at the lower limit and 2000 nm at the upper limit. If the thickness is 1 nm or more, holes can be blocked sufficiently, and if the thickness is 2000 nm or less, the layer is unlikely to become a resistance during electron transport, and the photoelectric conversion efficiency is increased. The more preferable lower limit of the thickness is 3 nm, the more preferable upper limit is 1000 nm, the even more preferable lower limit is 5 nm, and the even more preferable upper limit is 500 nm.

[0043] <Application Examples> Application examples of the present invention include photoelectric conversion devices, moving objects, and building materials. [Photoelectric conversion device] A photoelectric conversion device can be constructed by using a plurality of photoelectric conversion elements of the present invention. When a plurality of photoelectric conversion elements are connected, such a photoelectric conversion device can also be called a photoelectric conversion cell or a photoelectric conversion module. The photoelectric conversion element may be a stack of elements with different absorption wavelengths in order to increase the output voltage. The photoelectric conversion device may have the photoelectric conversion element of the present invention and an inverter. The inverter may be a converter that converts direct current to alternating current. The photoelectric conversion device may have a storage unit connected to the photoelectric conversion element. The storage unit is not limited as long as it can store electricity. For example, a secondary battery using lithium ions, an all-solid-state battery, and an electric double layer capacitor can be mentioned. In order to impart a function such as maintaining or increasing the amount of incident light, a surface layer that is resistant to water and dirt, or a function of collecting or guiding light may be added.

[0044] [Mobile object] FIG. 3 is a perspective view showing a schematic diagram of an embodiment of a moving body equipped with a photoelectric conversion element of the present invention. The moving body 30 has a photoelectric conversion element 31 of the present invention and a vehicle 32 equipped with the photoelectric conversion element 31. The photoelectric conversion element 31 is disposed at a position on the vehicle 32 where it can receive external light. If the moving body 30 is an automobile, the photoelectric conversion element 31 may be disposed on the roof. The electric energy obtained by the photoelectric conversion element 31 may be used as the power source for the moving body 30 or may be used as the power source for other electric devices. The electric energy generated from the power source of the moving body 30 may be used as the power source for the photoelectric conversion element 31. If the moving body 30 is an automobile, the frictional energy generated by the brakes may be converted into electric energy and used to control the photoelectric conversion element 31. The moving body 30 may be, for example, an automobile, a motorcycle, a railroad vehicle, a ship, an artificial satellite, an airplane, or a flying object including a drone. The configuration of the body 32 of the moving body 30 is not particularly limited, but it is preferable that the body 32 be made of a high-strength material.

[0045] [Building materials] 4 is a perspective view showing an embodiment of a building material including a photoelectric conversion element of the present invention. The building material 40 may be the roof of a building. The building material 40 of this embodiment has a photoelectric conversion element 41 of the present invention, a protective member 42 that protects the photoelectric conversion element 41, a heat dissipation member 43, and exteriors 44a and 44b. The building material 40 of the present invention may have a heat dissipation member 43 having a higher thermal conductivity than the photoelectric conversion element 41. In general, when a building material having a photoelectric conversion element is used on a roof or the like, the temperature of the photoelectric conversion element 41 may increase due to sunlight, and the photoelectric conversion efficiency may decrease. In this case, the decrease in photoelectric conversion efficiency can be reduced by using the heat dissipation member 43. Examples of the heat dissipation member 43 include metal, alloy, liquid metal, and liquid resin. The building material 40 of the present invention may have exteriors 44a and 44b. The exteriors 44a and 44b may emit different colors or the same color. The exteriors 44a and 44b may be made of the same material or different materials. Paint or a transparent substrate may be used as the exterior material, and it is preferable to use one with low light absorption and high heat insulation. In addition to the above application examples, the following application examples can be mentioned. Portable devices include, for example, calculators, sensors, and small solar panels. Wearable devices include, for example, eyeglass-type terminals, wristwatch-type terminals, and portable medical equipment. Sheet structures supported by multiple frames include, for example, tents, vinyl greenhouses, and truck beds. Fixed structures include, for example, road panels, floating panels, building materials that take advantage of the flexibility of the substrate, wall-type building materials, glass-type building materials, and mega solar panels.

[0046] [About the manufacturing method of photoelectric conversion element] A method for producing a photoelectric conversion element of the present invention includes the steps of forming a first electrode, forming a second electrode, and forming a photoelectric conversion layer containing crystals with a perovskite structure between the first electrode and the second electrode. Each step of the manufacturing method will be described below.

[0047] [Step of forming a first electrode and step of forming a second electrode] The method for manufacturing a photoelectric conversion element of the present invention includes a step of forming a first electrode and a step of forming a second electrode. In the step of forming the first electrode and the step of forming the second electrode, an appropriate method can be selected according to the material of the first electrode and the material of the second electrode, respectively. Examples of such methods include, but are not limited to, sputtering vacuum deposition, CVD (vapor phase deposition), and SPD (spray pyrolysis deposition). The materials of the first electrode and the second electrode are as described above. When either or both of the first electrode and the second electrode are transparent electrodes, the thickness of the transparent electrode is preferably 0.03 μm or more and 3 μm or less. When manufacturing a solar cell, cutting may be performed between each process to form a circuit. Examples of cutting include mechanical patterning and laser patterning.

[0048] [Modularization process] The element having the electrodes formed thereon may be sealed. Examples of the sealing method include sealing with a resin or sealing with a film. Examples of the material used for sealing include silazane, silicone rubber, a resin having a siloxane skeleton, and glass. In addition, from the viewpoint of preventing adhesion between elements that occurs when the elements are wound in a roll-to-roll system, the surfaces of the encapsulated elements may be subjected to a hairline treatment.

[0049] [Step of forming photoelectric conversion layer] The step of forming the photoelectric conversion layer may include a step of applying a liquid containing the material of the photoelectric conversion layer described above. Examples of the application method include spin coating, blade coating, slit die coating, screen printing, bar coater, casting, printing transfer, immersion and pulling, inkjet, spraying, and vacuum deposition. Among these, a method is appropriately selected according to the characteristics of the photoelectric conversion layer to be produced, such as thickness control and orientation control. In order to remove the solvent or dispersion medium from the liquid containing the applied photoelectric conversion layer material, annealing may be performed under reduced pressure or in an inert atmosphere (nitrogen or argon atmosphere). The temperature of the annealing is preferably 40° C. or higher and 300° C. or lower, and more preferably 50° C. or higher and 150° C. or lower. Note that annealing is preferable because it may increase the contact area at the interface between the stacked layers by allowing the materials constituting each layer to penetrate into each other, thereby increasing the short-circuit current.

[0050] [Step of forming charge transport layer] The step of forming the charge transport layer is preferably a method of applying a liquid containing the material of the charge transport layer. Examples of the application method include spin coating, blade coating, slit die coating, screen printing, bar coater, casting, printing transfer, immersion and pulling, inkjet, spraying, and vacuum deposition. Examples of the step of forming the charge transport layer include the following. This is a method of disposing crystals of a cyclic conjugated compound formed by conjugating multiple pyrrole rings and then applying a resin. Alternatively, this is a method of disposing crystals of a cyclic conjugated compound formed by conjugating multiple pyrrole rings and then applying a resin solution in which a resin is dissolved. Alternatively, this is a method of disposing a solution in which crystals of a cyclic conjugated compound formed by conjugating multiple pyrrole rings are dispersed in a resin solution in which a resin is dissolved.

[0051] <Method for identifying the amount of compound> The cyclic compound formed by covalently bonding a plurality of pyrrole rings in the charge transport layer used in the present invention, and the organic compound in the cyclic conjugated compound crystal were identified by the following method. The electrode surface of the photoelectric conversion element was peeled off to expose the charge transport layer surface. The charge transport layer surface was wiped with a cotton swab or the like soaked in a solvent such as chloroform to expose the charge transport layer. The exposed charge transport layer was peeled off and collected. The type of the organic compound of the present invention was identified for the collected charge transport layer using 1H-NMR, MALDI-TOF-MS, IR, and gas chromatography. In addition, the pKa of the present invention was measured by performing potentiometric titration on the organic compound identified by the above method. The film thickness was confirmed by cutting the photoelectric conversion element, fixing it on an inclined sample stage, and then performing cross-sectional SEM (apparatus: SmartSEM, Carl Zeiss Co., Ltd.). The crystallinity of the cyclic conjugated compound of the present invention was confirmed by detecting diffraction peaks by XRD measurement (apparatus: XRD apparatus RINT-TTRII, manufactured by Rigaku Denki Co., Ltd.). EXAMPLES

[0052] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited to the following examples without departing from the gist of the present invention. In the following description of the examples, "parts" are by mass unless otherwise specified.

[0053] Preparation of particle 1 Process (1) In a nitrogen flow atmosphere, 5.46 parts of orthophthalonitrile and 45 parts of α-chloronaphthalene were put into a reaction vessel, and then heated to a temperature of 30°C and maintained at this temperature. Next, 3.75 parts of gallium trichloride were put in at this temperature (30°C). The water concentration of the mixed liquid at the time of putting in was 150 ppm. Then, the temperature was raised to 200°C. Next, under a nitrogen flow atmosphere, the reaction was carried out at a temperature of 200°C for 4 hours, and then cooled, and when the temperature reached 150°C, the product was filtered. The obtained filtrate was dispersed and washed using N,N-dimethylformamide at a temperature of 140°C for 2 hours, and then filtered. The obtained filtrate was washed with methanol and then dried to obtain chlorogallium phthalocyanine particles with a yield of 65%.

[0054] Process (2) 4.65 parts of the chlorogallium phthalocyanine particles were dissolved in 139.5 parts of concentrated sulfuric acid at a temperature of 10°C, dropped into 620 parts of ice water under stirring to reprecipitate, and filtered under reduced pressure using a filter press. No. 5C (manufactured by Advantec Co., Ltd.) was used as the filter. The obtained wet cake (filtrate) was dispersed and washed with 2% ammonia water for 30 minutes, and then filtered using a filter press. Next, the obtained wet cake (filtrate) was dispersed and washed with ion-exchanged water, and then filtration using a filter press was repeated three times. Finally, freeze-drying was performed to obtain crude hydroxygallium phthalocyanine particles (hydrated hydroxygallium phthalocyanine particles) with a solid content of 23 mass% at a yield of 71%. The hydroxygallium phthalocyanine particles were dried using a hyper-dry dryer (trade name: HD-06R, frequency (oscillation frequency): 2455MHz±15MHz, manufactured by Japan Biocon Co., Ltd.) to obtain hydroxygallium phthalocyanine (OHGaPc) particles (crystals).

[0055] Process (3) Two parts of the hydroxygallium phthalocyanine particles were mixed with 5 parts of N-methylformamide solvent, and the mixture was dispersed at 500 rpm for 20 hours using a sand mill (TSG-1, manufactured by Igarashi Machinery Manufacturing Co., Ltd. (now Imex), disk diameter 70 mm, number of disks 5) containing 5 parts of glass beads, filtered, and dried to obtain Particle 1.

[0056] (Preparation of particles 2 to 18) Particles 2 to 5, 14, 15, and 18 were prepared in the same manner as particle (1), except that in step (3) of the preparation of particle 1, a solvent (organic compound) as shown in Table 2 below was used instead of N-methylformamide, and the treatment time and rotation speed in step (3) of the preparation of particle 1 were changed. Particles 10 to 12 and 17 were prepared in the same manner as particle 1, except that in step (1) of the preparation of particle 1, gallium trichloride was changed to various corresponding metal compounds, the amount ratio of particles to solvent and various reaction conditions were changed, and in step (3) of the preparation of particle 1, the solvent was changed to the amount shown in Table 2. Particles 6 to 9 were prepared in the same manner as particle 1, except that in step (3) of the preparation of particle 1, the amount ratio of particles to solvent, treatment time, and rotation speed were changed. Particles 13 were produced in the same manner as in the production of Particles 1, except that step (2) was not carried out and the particles obtained in step (1) were directly treated in step (3). Particles 16 were produced according to the method described in Japanese Patent No. 5132013.

[0057] [Table 2] (In Table 2, NMF stands for N-methylformamide, IPA stands for 2-propanol, NEF stands for N-ethylformamide, NPF stands for N-propylformamide, DMSO stands for dimethylsulfoxide, and DMF stands for N,N-dimethylformamide.)

[0058] Example 1 [Formation of Electron Transport Layer] A glass substrate with ITO was cleaned, and tin oxide (2) adjusted to 3% by mass was spin-coated onto it using a spin coater, and then heated at 150°C for 30 minutes to form a thin-film electron transport layer with a thickness of 15 nm.

[0059] [Formation of photoelectric conversion layer] 17.9 mg of methylammonium bromide, 137.6 mg of formamidium iodide, and 460.8 mg of lead iodide were dissolved in 600 μL of N,N-dimethylformamide and 160 μL of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 1). Furthermore, 389.72 mg of cesium iodide was dissolved in 1000 μL of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 2). Then, 34 μL of the dissolved cesium iodide solution (solution 2) was added to solution 1 to prepare a coating solution for the photoelectric conversion layer. This coating solution was spin-coated on the electron transport layer to obtain Cs 0.05 (FA 0.83 MA 0.17 ) 0.96 Pb(I 0.95 Br 0.05 A photoelectric conversion layer having a thickness of 400 nm was formed from the photoelectric conversion layer 3.

[0060] [Formation of Charge Transport Layer] 1.0 g of polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 19 g of 2-propanol with stirring for 24 hours to obtain a resin solution 1. 0.1g of the particles 1 and 0.01g of a calixarene compound (exemplified compound 1 in JP-A-2003-207913) were mixed with 12.8g of 2-propanol, 11g of zirconia beads were encapsulated in this mixture, and dispersion was performed for 6 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.). Then, 0.2g of resin solution 1 was added, and dispersion was performed again for 6 hours using a paint shaker to prepare a coating liquid for a charge transport layer. This coating liquid for a charge transport layer was spin-coated on the photoelectric conversion layer to form a charge transport layer having a thickness of 150nm.

[0061] [Introduction of a second charge transport layer] 0.098 g of Spiro-OMeTAD as a hole transport material was dissolved in 2.2 g of chlorobenzene. 36 μL of acetonitrile solution obtained by dissolving 0.13 g of lithium bis(trifluoromethanesulfonyl)imide in 0.30 g of acetonitrile and 24 μL of t-butylpyridine (TBP) were added to this chlorobenzene solution and mixed. Furthermore, 58 μL of acetonitrile solution obtained by dissolving 0.10 g of [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(3)tris(bis(trifluoromethylsulfonyl)imide)] in 0.30 g of acetonitrile was mixed to prepare a second charge transport layer coating solution. This was applied by spin coating on the charge transport layer to form a hole transport layer with a thickness of 130 nm.

[0062] [Formation of the first electrode] On the second charge transport layer, a layer having a thickness of 80 nm and an area of ​​0.09 cm 2 A gold electrode was formed by vacuum deposition to obtain a photoelectric conversion element.

[0063] Example 2 In Example 2, a photoelectric conversion element was produced in the same manner as in Example 1, except that particles 1 were changed to particles 2 in the formation of the charge transport layer.

[0064] Example 3 In Example 3, a photoelectric conversion element was produced in the same manner as in Example 1, except that particles 1 were changed to particles 3 in the formation of the charge transport layer.

[0065] Example 4 In Example 4, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 4 in the formation of the charge transport layer.

[0066] Example 5 In Example 5, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 5 in the formation of the charge transport layer.

[0067] Example 6 In Example 6, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 6 in the formation of the charge transport layer.

[0068] Example 7 In Example 7, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 7 in the formation of the charge transport layer.

[0069] Example 8 In Example 8, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 8 in the formation of the charge transport layer.

[0070] Example 9 In Example 9, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 9 in the formation of the charge transport layer.

[0071] Example 10 In Example 10, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, the particles 1 were changed to the particles 10 and polyvinyl butyral was not added.

[0072] Example 11 In Example 11, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, particles 1 were changed to particles 11 and polyvinyl butyral was not added.

[0073] Example 12 In Example 12, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, the particles 1 were changed to the particles 12 and polyvinyl butyral was not added.

[0074] (Example 13) In Example 13, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, particles 1 were changed to particles 13 and polyvinyl butyral was not added.

[0075] Example 14 In Example 14, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 14 in the formation of the charge transport layer.

[0076] Example 15 In Example 15, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 15 in the formation of the charge transport layer.

[0077] (Example 16) In Example 16, a photoelectric conversion element was prepared in the same manner as in Example 1, except that particles 1 were changed to particles 16 in the formation of the charge transport layer.

[0078] (Example 17) In Example 17, a photoelectric conversion element was prepared in the same manner as in Example 1, except that the amount of polyvinyl butyral added in forming the charge transport layer was changed.

[0079] (Example 18) In Example 18, a photoelectric conversion element was prepared in the same manner as in Example 1, except that polyvinyl butyral was not added in the formation of the charge transport layer.

[0080] Comparative Example 1 In Comparative Example 1, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, the particles 1 were changed to the particles 17 and polyvinyl butyral was not added.

[0081] Comparative Example 2 In Comparative Example 1, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, particles 1 were changed to particles 18 and polyvinyl butyral was not added.

[0082] Comparative Example 3 In Comparative Example 3, a photoelectric conversion element was prepared in the same manner as in Example 1, except that the charge transport layer was not formed.

[0083] Comparative Example 4 In Comparative Example 4, a photoelectric conversion element was prepared in the same manner as in Example 1, except that in forming the charge transport layer, the particles 1 were changed to copper phthalocyanine (manufactured by TCI). When the copper phthalocyanine was analyzed, no organic compound was detected in the crystals.

[0084] Examples 1 to 18 and Comparative Examples 1 to 4 are shown in Table 3. [Table 3] (In Table 3, abbreviations such as NMF represent the same compounds as in Table 2.)

[0085] [evaluation] The photoelectric conversion elements obtained in each of the Examples and Comparative Examples were evaluated as follows. (Evaluation of Power Generation Efficiency) In Example 1, a power supply (KEITHLEY, Model 236) was connected between the electrodes of the photoelectric conversion element, and the intensity was 100 mW / cm 2 The photoelectric conversion efficiency was evaluated by irradiating a constant amount of light using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) and measuring the generated current and voltage. The fabricated photoelectric conversion element was left for one month in an environment with a temperature of 30°C and a humidity of 60% RH, and then the photoelectric conversion efficiency was determined by the same measurement method as above. The value of the photoelectric conversion efficiency after being left for one month relative to the initial photoelectric conversion efficiency was taken as the maintenance rate of the photoelectric conversion efficiency. Examples 1 to 18 and Comparative Examples 1 to 4 were also evaluated in the same manner as in Example 1, and the photoelectric conversion efficiency and the maintenance rate of the photoelectric conversion efficiency were determined. The results are shown in Table 4.

[0086] [Table 4]

[0087] The disclosure of this embodiment includes the following configuration. [Configuration 1] A first electrode and a second electrode, A photoelectric conversion element having a photoelectric conversion layer including a crystal having a perovskite structure, the photoelectric conversion layer being disposed between the first electrode and the second electrode, a layer having a crystal of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings is provided between the photoelectric conversion layer and the first electrode; A photoelectric conversion element comprising an organic compound in a crystal of the cyclic conjugated compound formed by conjugating the multiple pyrrole rings, the organic compound having a pKa of 10.0 or more and a dipole moment of 1.60 D or more. [Configuration 2] The molar volume of the organic compound is 20.0 cm 3 / mol or more 85.0cm 3 / mol or less. [Configuration 3] 3. The photoelectric conversion element according to configuration 1 or 2, wherein the organic compound is contained in an amount of 0.50% by mass to 2.00% by mass with respect to the cyclic conjugated compound formed by conjugating the multiple pyrrole rings. [Configuration 4] 4. The photoelectric conversion element according to any one of configurations 1 to 3, wherein the cyclic conjugated compound formed by conjugating the plurality of pyrrole rings contains any one of Ga, Ti and Zn as a central element. [Configuration 5] The photoelectric conversion element according to configuration 4, wherein the central element is Ga. [Configuration 6] The photoelectric conversion element according to any one of configurations 1 to 5, wherein the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings has at least one selected from the group consisting of OH, Cl, and O as an axial ligand. [Configuration 7] 7. The photoelectric conversion element according to any one of configurations 1 to 6, wherein the organic compound has a pKa of 10.0 or more and 40.0 or less. [Configuration 8] 8. The photoelectric conversion element according to any one of configurations 1 to 7, wherein the organic compound has a dipole moment of 2.20 D or more. [Configuration 9] 9. The photoelectric conversion element according to any one of configurations 1 to 8, wherein the organic compound is any one selected from the group consisting of N-methylformamide, N-ethylformamide, N-propylformamide, and dimethylsulfoxide. [Configuration 10] The photoelectric conversion element according to any one of configurations 1 to 9, wherein the layer having the crystals of the cyclic conjugated compound formed by the conjugated bonds of the plurality of pyrrole rings has a resin, and when the content of the resin in the layer is B and the content of the cyclic conjugated compound formed by the conjugated bonds of the plurality of pyrrole rings in the layer is P, P / B is 1 or more and 20 or less. [Configuration 11] 11. The photoelectric conversion element according to any one of configurations 1 to 10, wherein the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings is a phthalocyanine compound. [Configuration 12] 12. A photoelectric conversion device comprising the photoelectric conversion element according to any one of configurations 1 to 11. [Explanation of symbols]

[0088] 1 Photoelectric conversion element 2. Board 3 Second electrode 4 Electron transport layer 5 Photoelectric conversion layer 6 Charge transport layer 7 First electrode 30 Mobile 31, 41 Photoelectric conversion element 32 Aircraft 40 Building materials 42 Protective materials 43 Heat dissipation materials 44a, 44b Exterior

Claims

1. A first electrode and a second electrode, a photoelectric conversion layer including a crystal having a perovskite structure, the photoelectric conversion layer being disposed between the first electrode and the second electrode; A photoelectric conversion element having a layer having a crystal of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings is provided between the photoelectric conversion layer and the first electrode; A photoelectric conversion element comprising an organic compound in a crystal of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings, the organic compound having a pKa of 10.0 or more and a dipole moment of 1.60 D or more.

2. The molar volume of the organic compound is 20.0 cm ３ / mol or more 85.0cm ３ 2. The photoelectric conversion element according to claim 1, wherein the molecular weight is 1.0 to 1.0 mol / mol or less.

3. 2 . The photoelectric conversion element according to claim 1 , wherein the organic compound is contained in an amount of 0.50% by mass to 2.00% by mass with respect to the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings.

4. The photoelectric conversion element according to claim 1 , wherein the cyclic conjugated compound formed by conjugating the plurality of pyrrole rings contains any one of Ga, Ti, and Zn as a central element.

5. The photoelectric conversion element according to claim 4 , wherein the central element is Ga.

6. 2. The photoelectric conversion element according to claim 1, wherein the cyclic conjugated compound formed by conjugating the plurality of pyrrole rings has at least one selected from the group consisting of OH, Cl and O as an axial ligand.

7. 2. The photoelectric conversion element according to claim 1, wherein the organic compound has a pKa value of 10.0 or more and 40.0 or less.

8. 2. The photoelectric conversion element according to claim 1, wherein the organic compound has a dipole moment of 2.20 D or more.

9. 2. The photoelectric conversion element according to claim 1, wherein the organic compound is any one selected from the group consisting of N-methylformamide, N-ethylformamide, N-propylformamide, and dimethylsulfoxide.

10. 2. The photoelectric conversion element according to claim 1, wherein the layer having the crystals of the cyclic conjugated compound formed by the conjugated bonds of the plurality of pyrrole rings contains a resin, and when the content of the resin in the layer is B and the content of the cyclic conjugated compound formed by the conjugated bonds of the plurality of pyrrole rings in the layer is P, P / B is 1 or more and 20 or less.

11. 2. The photoelectric conversion element according to claim 1, wherein the cyclic conjugated compound formed by conjugating a plurality of pyrrole rings is a phthalocyanine compound.

12. A photoelectric conversion device comprising the photoelectric conversion element according to any one of claims 1 to 11.

Images