Photoelectric conversion element and photoelectric conversion device

Abstract

To provide a photoelectric conversion element and a photoelectric conversion device that are improved in conversion efficiency.SOLUTION: A photoelectric conversion element has a photoelectric conversion layer including a crystal of a perovskite structure. The photoelectric conversion element has, between the photoelectric conversion layer and a first electrode, a charge transport layer containing a crystal of an annular conjugated compound in which a plurality of pyrrole rings are conjugated and bonded. At the Bragg angle 2θ in an X-ray diffraction spectrum using a CuKα ray for the charge transport layer, when a peak with the maximum intensity, of peaks present within a range of 5.0°-8.0°, is defined as a peak α, and a peak with the maximum intensity, of peaks present within a range of 26.0°-29.0°, is defined as a peak β, one of the peak α and the peak β is a peak with the maximum intensity within a scan range. When the intensity of the peak α is defined as Iα, and the intensity of the peak β as Iβ, Iα / Iβ is 2.0 or less.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] In order to solve the problem of fossil energy depletion and the global environmental problems caused by the use of fossil energy, active research is being conducted on renewable and clean alternative energy sources such as solar energy, wind power, and hydroelectric power. Among them, interest in solar cells that directly convert sunlight into electrical energy is increasing. Here, a solar cell refers to a cell that generates a current and voltage by utilizing the photovoltaic effect in which light energy from sunlight is absorbed and electrons and holes are generated.

[0003] Currently, np diode type silicon (Si) single crystal-based solar cells with a light energy conversion efficiency of over 20% are widely known and are actually used for photovoltaic power generation. However, these require high-temperature processing and the materials themselves are expensive, so they have the problem of high cost per unit of power. In addition, there are problems with supply in terms of silicon resources.

[0004] On the other hand, solar cells using organic materials (hereinafter referred to as "organic solar cells") do not require high-temperature processing and can be produced by the so-called roll-to-roll method using a sheet-like substrate, which is expected to reduce costs. However, further improvements in power generation efficiency and durability are desired for practical use of organic solar cells. In particular, perovskite-type solar cells having crystals with a perovskite structure as a photoelectric conversion layer have excellent photoelectric conversion properties, so development is being advanced toward practical use of solar cells. For example, Patent Document 1 describes the improvement of conversion efficiency by forming a layer containing a phthalocyanine compound between a hole transport layer (hereinafter also referred to as a "charge transport layer") and perovskite. Non-Patent Document 1 describes the improvement of conversion efficiency by including copper phthalocyanine in the hole transport layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2022-168820 [Non-patent literature]

[0006] [Non-Patent Document 1] F. Wang,et al,J.Phys.Chem.C,2017,121,1562 Summary of the Invention [Problem to be solved by the invention]

[0007] According to the investigations of the present inventors, it was necessary to achieve a further improvement in conversion efficiency in the above-mentioned conventional techniques in order to put them into practical use. An object of the present invention is to provide a photoelectric conversion element and a photoelectric conversion device with improved conversion efficiency. [Means for solving the problem]

[0008] The above object can be achieved by the present invention. That is, the photoelectric conversion element according to the present invention comprises: 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 the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer containing a crystal of a cyclic conjugated compound in which a plurality of pyrrole rings are conjugatedly bonded; in a scanning range of 3.0° to 30.0° of Bragg angle 2θ in an X-ray diffraction spectrum using CuKα radiation of the charge transport layer, the peak with the maximum intensity among peaks existing within a range of 5.0° to 8.0° is defined as peak α, and the peak with the maximum intensity among peaks existing within a range of 26.0° to 29.0° is defined as peak β, either peak α or peak β is the peak with the maximum intensity in the scanning range, When the intensity of the peak α is Iα and the intensity of the peak β is Iβ, the Iα / Iβ ratio is 2.0 or less. Effect of the Invention

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

[0010] [Figure 1] FIG. 2 is a schematic diagram of the crystal structure of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings contained in a charge transport layer according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a crystal structure of a cyclic conjugated compound formed by conjugating a plurality of pyrrole rings contained in a charge transport layer according to a comparative example of the present invention. [Diagram 3] 1 is a schematic cross-sectional view in a thickness direction of a first embodiment of a photoelectric conversion element of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view in the thickness direction of a second embodiment of a photoelectric conversion element of the present invention. [Diagram 5] 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 6] FIG. 1 is a perspective view illustrating 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 photoelectric conversion element of the present invention has 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. A charge transport layer containing a cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings is provided between the photoelectric conversion layer and the first electrode.

[0012] The present inventors have found that the inclusion of the charge transport layer results in a photoelectric conversion element with excellent conversion efficiency. Although the details of why high stability is obtained in the present invention are not clear, the mechanism is thought to be as follows.

[0013] According to prior art documents, when a photoelectric conversion layer contains crystals with a perovskite structure, submicron irregularities are generated on the surface. It is presumed that filling the concaves of such irregularities with pigment particles made of a phthalocyanine compound, which is a type of cyclic compound formed by covalently bonding multiple pyrrole rings, stabilizes the interface bond with the electrode and allows high photoelectric conversion efficiency to be obtained. However, it has been found that this alone is insufficient to obtain a higher conversion efficiency.

[0014] Therefore, the present inventors presume that the formation of a charge transport layer that exhibits a specific X-ray diffraction peak by a cyclic conjugated compound in which a plurality of pyrrole rings are covalently bonded contributes to the improvement of the conversion efficiency.

[0015] Specifically, in a scanning range of 3.0° to 30.0° of the Bragg angle 2θ in an X-ray diffraction spectrum using CuKα radiation (λ=1.5418 Å) of the charge transport layer, when the peak with the greatest intensity among the peaks present within the range of 5.0° to 8.0° is defined as peak α, and the peak with the greatest intensity among the peaks present within the range of 26.0° to 29.0° is defined as peak β, either peak α or peak β is the peak with the greatest intensity in the scanning range, and when the intensity of peak α is defined as Iα and the intensity of peak β is defined as Iβ, the conversion efficiency can be improved by Iα / Iβ being 2.0 or less.

[0016] It is believed that the strong peak intensity (Iα) in the range of 5.0° to 8.0° indicates that there are many crystals (Figure 1) in which the cyclic conjugated compounds are stacked in the horizontal direction (molecular spacing is about 12 Å according to the Bragg formula), and the strong peak intensity (Iβ) in the range of 26.0° to 29.0° indicates that there are many crystals (Figure 2) in which the cyclic conjugated compounds are stacked in the vertical direction (film thickness direction) (molecular spacing is about 3 Å according to the Bragg formula). In other words, the smaller the Iα / Iβ, the higher the proportion of crystals stacked in the vertical direction compared to crystals stacked in the horizontal direction.

[0017] Vertical stacking is the direction in which π electron clouds overlap, which is expected to result in high efficiency in the transport of carriers moving within the film. It is therefore speculated that the presence of a certain number of vertically stacked crystals contributes to improved conversion efficiency.

[0018] In FIG. 1, 1 denotes a cyclic conjugated compound molecule (flat structure) formed by conjugating multiple pyrrole rings, and 2 denotes the entire crystal. In FIG. 2, 1 denotes a cyclic conjugated compound molecule (flat structure) formed by conjugating multiple pyrrole rings, and 3 denotes the entire crystal.

[0019] The effects of the present invention can be achieved through the above mechanism. 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 any modifications or improvements to the following embodiments based on the ordinary knowledge of a person skilled in the art without departing from the spirit of the present invention are also included in the scope 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 and intricate structure together with other layers.

[0020] 3 is a cross-sectional view showing a schematic configuration of one embodiment of the photoelectric conversion element of the present invention. A second electrode 5, an electron transport layer 6, a photoelectric conversion layer 7, a charge transport layer 8, and a first electrode 9 are provided on a substrate 4. One of the first electrode 9 and the second electrode 5 is an anode and the other is a cathode, and a current can be extracted by connecting the first electrode 9 and the second electrode 5 to an external circuit.

[0021] The photoelectric conversion layer 7 is excited by light incident through the substrate 4, the second electrode 5, and the electron transport layer 6, or through the first electrode 9 and the charge transport layer 8, and generates electrons or holes. That is, the photoelectric conversion layer 7 generates a current between the first electrode 9 and the second electrode 5. The electron transport layer 6 is a layer disposed between the photoelectric conversion layer 7 and the two electrodes 5, 9, and may not be formed in some cases. A configuration in which a plurality of electron transport layers 6 and photoelectric conversion layers 7 are stacked may be used. Such a configuration may be called a tandem structure.

[0022] Alternatively, a first electrode 9, a charge transport layer 8, a photoelectric conversion layer 7, an electron transport layer 6, and a second electrode 5 may be provided on a substrate 4 (FIG. 4).

[0023] Each component 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.

[0024] 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.

[0025] Each layer will be described below. 〔substrate〕 The photoelectric conversion element of the present invention may include a substrate, for example, a transparent glass substrate such as soda lime glass or alkali-free glass, a ceramic substrate, or a transparent plastic substrate. When light is taken in from the first electrode 9 side in Fig. 4, an opaque material can be used for the substrate 4, and when light is taken in from the second electrode 5 side in Fig. 5, the substrate 4 is made of a transparent material.

[0026] 〔electrode〕 The materials of the first electrode and the second electrode are not particularly limited, and conventionally known materials 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. Transparent electrode materials include, for example, 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 may be used in combination. At least one of the first electrode and the second electrode on the light incident side is 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, and may be a transparent electrode provided with a reflective layer on the opposite side to the light incident side. As a photoelectric conversion element, it is preferable that the first electrode is a positive electrode. When the first electrode is on the light incident side, the second electrode may be a transparent electrode and the substrate may be a reflective layer. The transparent electrode may be a patterned electrode.

[0027] [Photoelectric Conversion Layer] The photoelectric conversion layer 7 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.

[0028] 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] 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. 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.

[0029] 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.

[0030] X in the above general formulas [1] to [4] is a halogen atom, such as chlorine, bromine, iodine, sulfur, and selenium. 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 and the like. Furthermore, iodine is more preferred because the energy band gap of the perovskite crystals is narrowed.

[0031] 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 (FA x2 MA 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 PbI 3、 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)2MA4Pb5I16 , (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. [Table 1] 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.

[0032] 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 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.

[0033] 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.

[0034] 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.

[0035] [Charge transport layer] The charge transport layer 8 of the present invention has crystals of a cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings. The cyclic conjugated compound used in the present invention, which is formed by covalently bonding a plurality of pyrrole rings, is preferably a porphyrin compound or a phthalocyanine compound, more preferably a phthalocyanine compound, from the viewpoint of the spread of the π-electron cloud that is the starting point of the interaction. The phthalocyanine compound may have a central element, and examples of the central element include Ga, Cu, Ti, Zn, Si, V, Pb, Pt, Co, Sn, Mg, Fe, Al, and Mn, and among them, a gallium phthalocyanine compound in which the central element is Ga or a titanyl phthalocyanine compound in which the central metal is Ti is preferred. A hydroxygallium phthalocyanine compound is more preferred.

[0036] Specific examples of the cyclic conjugated compound in which a plurality of pyrrole rings are covalently bonded in the present invention are given below. Porphyrin derivatives such as tetraphenylporphyrin, diphenylporphyrin, tetrapyridylporphyrin, copper porphyrin, copper tetraphenylporphyrin, copper octaethylporphyrin, cobalt tetraphenylporphyrin, octaethylporphyrin, chlorophenylporphyrin, methoxyphenylporphyrin, methylphenylporphyrin, zinc porphyrin, magnesium porphyrin, octabutoxyporphyrin, manganese chloroporphyrin, metal-free tetraazaporphyrin, copper tetraazaporphyrin, zinc tetraazaporphyrin, nickel tetraazaporphyrin, titanyl tetraazaporphyrin, tetraphenyltetraazaporphyrin, and octaphenyltetraazaporphyrin. Phthalocyanine derivatives such as hydroxygallium phthalocyanine, chlorogallium phthalocyanine, copper phthalocyanine, zinc phthalocyanine, phthalocyanine, cobalt phthalocyanine, titanyl phthalocyanine, dichlorotin phthalocyanine, magnesium phthalocyanine, tin phthalocyanine, lead phthalocyanine, iron phthalocyanine, vanadyl phthalocyanine, chloroaluminum phthalocyanine, nickel phthalocyanine, dichlorosilicon phthalocyanine, indium chlorophthalocyanine, manganese phthalocyanine, chloroiron phthalocyanine, and platinum phthalocyanine. Naphthalocyanine derivatives such as naphthalocyanine, magnesium naphthalocyanine, copper naphthalocyanine, magnesium naphthalocyanine, cobalt naphthalocyanine, vanadyl naphthalocyanine, tin naphthalocyanine, and dichlorotin naphthalocyanine.

[0037] The charge transport layer may contain a resin. From the viewpoint of film-forming properties and charge transport ability, the content of the resin in the charge transport layer is preferably 3% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, based on the content of the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings.

[0038] The molecular weight of the resin is preferably 10,000 or more. 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. From the viewpoint of film-forming properties, the glass transition point of the resin is preferably 60° C. or higher and 95° C. or lower. The charge transport layer may contain an aromatic ring compound containing a hydroxyl group. From the viewpoint of film-forming properties and charge transport ability, the content of the aromatic ring compound containing a hydroxyl group in the charge transport layer is preferably from 1% by mass to 30% by mass, more preferably from 5% by mass to 20% by mass, based on the content of the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings. Examples of aromatic ring compounds containing a hydroxyl group that are preferably used in the present invention include calixarene compounds. In an X-ray diffraction spectrum of this charge transport layer using CuKα radiation, in a scanning range of 3.0° to 30.0° of Bragg angle 2θ, when the peak with the greatest intensity among the peaks present in the range of 5.0° to 8.0° is defined as peak α, and the peak with the greatest intensity among the peaks present in the range of 26.0° to 29.0° is defined as peak β, either peak α or peak β is the peak with the greatest intensity in the scanning range, and when the intensity of peak α is defined as Iα and the intensity of peak β is defined as Iβ, Iα / Iβ is 2.0 or less. Iα / Iβ is preferably 1.5 or less, and more preferably 1.0 or less.

[0039] It is more preferable that the peak α is within a range of 7.2° to 7.6° and the peak β is within a range of 28.0° to 28.4°, and that the above Iα / Iβ value is satisfied. Examples of a dispersion method for forming particles of crystals of a cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings include a method using a paint shaker, a sand mill, a ball mill, or a liquid collision type high-speed disperser. Among these, sand mills break down crystals into particles using shear forces from the rotation of a rotating disk inside the mill and from media such as glass beads that serve as grinding media, but the peak ratio changes as the crystallinity changes depending on the dispersion conditions, such as the dispersion time, amount of beads, and disk rotation speed. For example, if the dispersion time is extended to the extent that overdispersion (aggregation of particles or formation of fragments, etc.) does not occur, the Iα / Iβ tends to decrease. The thickness of the charge transport layer is preferably from 1 nm to 1000 nm, more preferably from 5 nm to 500 nm, and particularly preferably from 10 nm to 200 nm.

[0040] The measurement of the X-ray diffraction spectrum of the charge transport layer used in the present invention and the confirmation of the cyclic compounds formed by covalently bonding a plurality of pyrrole rings contained therein were carried out by removing the layers above the charge transport layer of the photoelectric conversion element of the present invention with an organic solvent such as chloroform, exposing the surface of the charge transport layer, and then carrying out the following method.

[0041] [Analysis of compound amounts] The surface of the charge transport layer was wiped with a cotton swab soaked in a solvent, dissolved in heavy water and sulfuric acid, and 1HNMR measurement (apparatus: BRUKER, AVANCE3-500) was performed. In addition, the peeled off components were subjected to mass and structural analysis by GPC, MALDI-TOF-MS, IR, and gas chromatography to confirm the presence of the compound. The film thickness was confirmed by cutting the photoelectric conversion element, fixing it to an inclined sample stage, and then observing the cross-section with a SEM (apparatus: Carl Zeiss, SmartSEM). MALDI-TOF-MS analysis The analysis was carried out under the following conditions, and the molecular weight was confirmed from the obtained peak top value. Measurement equipment used: Bruker Daltonics, matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (MALDI-TOF MS) ultraflex Accelerating voltage: 20 kV Mode: Reflector Molecular weight standard: Fullerene C60

[0042] [X-ray diffraction measurement] The X-ray diffraction spectrum of the exposed charge transport layer was measured, and the peak intensity ratio (Iα / Iβ) was calculated. Measuring equipment used: Rigaku Electric Co., Ltd., X-ray diffraction device RINT-TTRII X-ray tube:Cu X-ray wavelength: Kα1 Tube voltage: 50KV Tube current: 300mA Scan method: 2θ-θ scan Scan speed: 4.0° / min Sampling interval: 0.02° Start angle 2θ: 3.0° Stop angle 2θ: 30.0° Goniometer: Rotor horizontal goniometer (TTR-2) Filter: None Detector: Scintillation counter Incident Monochrome: Use Slit: Variable slit (parallel beam method) Counter monochromator: Not used Divergence slit: open Divergence vertical limit slit: 10.00mm Scattering slit: open Receiving slit: open

[0043] [Second Charge Transport Layer] In the present invention, from the viewpoint of film compatibility of the charge transport layer, a second charge transport layer may be provided between the charge transport layer 8 and the first electrode 9 in FIG. 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-OMeTA, 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.

[0044] [Electron transport layer] In the photoelectric conversion element of the present invention, as shown in FIG. 1, an electron transport layer 6 may be disposed between the second electrode 5 and the photoelectric conversion layer 7. The material of the electron transport layer 6 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, and surfactants. 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 derivatives, 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 6 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 thickness is more preferably 3 nm at the lower limit and 1000 nm at the upper limit, and even more preferably 5 nm at the lower limit and 500 nm at the upper limit.

[0045] <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 having different absorption wavelengths in order to increase the output voltage. The photoelectric conversion device has 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 provide a function of 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.

[0046] [Mobile object] 5 is a perspective view showing a schematic diagram of one embodiment of a moving body including a photoelectric conversion element of the present invention. A moving body 30 includes a photoelectric conversion element 31 of the present invention and a body 32 including the photoelectric conversion element 31. The photoelectric conversion element 31 is disposed in a position on the body 32 where it can receive external light. If the moving object 30 is an automobile, it may be disposed on the roof. The electric energy obtained by the photoelectric conversion element 31 may power the moving object 30 or may power other electric devices. The electric energy generated from the power of the moving object 30 may be used to power the photoelectric conversion element 31. If the moving object 30 is an automobile, frictional energy generated by braking 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.

[0047] [Building materials] 6 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. When 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. The use of the heat dissipation member 43 can reduce the decrease in photoelectric conversion efficiency. Examples of the heat dissipation member 43 include metal, alloy, liquid metal, and liquid resin. Furthermore, the building material 40 of the present invention may have exteriors 44a and 44b. The exteriors 44a and 44b may emit different colors or may be the same. 44a and 44b may be made of the same material or different materials. Paint or a transparent substrate may be used as the exterior. A material with low light absorption and high heat insulation is preferable.

[0048] In addition to the above application examples, the following application examples are also available. 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.

[0049] [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.

[0050] [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.

[0051] [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.

[0052] [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, mold method, print transfer method, immersion and pulling method, inkjet method, spray method, vacuum deposition method, etc. Among these, the 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 applied liquid containing the material of the photoelectric conversion layer, an annealing treatment may be performed under reduced pressure or in an inert atmosphere (nitrogen, argon atmosphere). The temperature of the annealing treatment is preferably 40°C or higher and 300°C or lower, more preferably 50°C or higher and 150°C or lower. Note that, by performing the annealing treatment, the contact area increases at the interface between the stacked layers due to the penetration of the materials constituting each layer into each other, which may increase the short-circuit current, which is preferable.

[0053] [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. A method in which charge transport particles are disposed on the surface of a photoelectric conversion layer, and then a resin solution in which a resin is dissolved is applied and dried. Alternatively, a method in which a resin solution in which a resin is dissolved is applied on the surface of a photoelectric conversion layer, and then charge transport particles are disposed, and then the resin solution is dried. Alternatively, a method in which a solution in which charge transport particles are dispersed in a resin solution in which a resin is dissolved is applied on the surface of a photoelectric conversion layer, and then dried. EXAMPLES

[0054] 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.

[0055] (Process for Producing Particle 1 Containing Cyclic Compound Crystals Formed by Conjugated Bonds of Multiple Pyrrole Rings) 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 4.5 hours, and then cooled. 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 71%.

[0056] 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 hydroxygallium phthalocyanine particles (hydrated hydroxygallium phthalocyanine particles) with a solid content of 23% by 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 particles (crystals) with a water content of 1.0% by mass or less.

[0057] Process (3) One part of the hydroxygallium phthalocyanine particles was dispersed in 5 parts of N-methylformamide solvent and 5 parts of glass beads in a sand mill (TSG-1 / 4G-4U, manufactured by Igarashi Machine Manufacturing Co., Ltd. (now Imex), disk diameter 70 mm, number of disks 5) by rotating the disks at 300 rpm for 100 hours, followed by filtration and drying to obtain Particle 1.

[0058] (Preparation of resin solution 1) 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. (Preparation of resin solution 2) 1.0 g of polyacrylic acid (molecular weight 5000, Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 19 g of ethanol with stirring for 24 hours to obtain resin solution 2.

[0059] Example 1 [Formation of Electron Transport Layer] A glass substrate with ITO was cleaned, and tin(II) oxide adjusted to 3% by mass was applied thereon by spin coating. The substrate was then heated at 150° C. for 30 minutes to form a thin-film electron transport layer having a thickness of 15 nm.

[0060] [Formation of photoelectric conversion layer] 22.4 mg of methylammonium bromide, 172 mg of formamidium iodide, and 576 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, 40 μL of the dissolved cesium iodide solution (solution 2) was added to solution 1 to prepare a photoelectric conversion layer coating solution. 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.

[0061] [Formation of Charge Transport Layer] 0.1 g of the particles 1 and 0.01 g of a calixarene compound (exemplified compound 1 described in JP-A-2003-207913) were enclosed in 10.6 g of 2-propanol and 11 g of zirconia beads, and dispersed for 8 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.) 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 150 nm.

[0062] [Introduction of a second charge transport layer] 0.15 g of Spiro-OMeTAD as a material for the second charge transport layer was dissolved in 2.2 g of chlorobenzene. 36 μL of an acetonitrile solution obtained by dissolving 0.2 g of lithium bis(trifluoromethanesulfonyl)imide in 0.3 g of acetonitrile and 60 μL of t-butylpyridine (TBP) were added to this chlorobenzene solution and mixed. Furthermore, 58 μL of an acetonitrile solution obtained by dissolving 0.11 g of [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III)tris(bis(trifluoromethylsulfonyl)imide)] in 0.3 g of acetonitrile was mixed to prepare a coating solution for the second charge transport layer. This was applied by spin coating on the charge transport layer to form a second charge transport layer with a thickness of 150 nm.

[0063] [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.

[0064] [Power generation efficiency evaluation] 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 the device with a constant amount of light using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) and measuring the generated current and voltage. The results are shown in Table 2.

[0065] Comparative Example 1 A photoelectric conversion element was prepared and evaluated in the same manner as in Example 1 except that the cyclic conjugated compound was changed to that shown in Table 1 (Particle 1 used in Example 1 of JP-A-2022-168820). The results are shown in Table 2.

[0066] (Examples 2 to 16, Comparative Examples 2 and 3) Photoelectric conversion elements are prepared in the same manner as in Example 1, except that the type of cyclic conjugated compound, whether or not a resin solution is added when preparing the charge transport layer solution, the type of the resin solution, and the amount of the resin solution are changed. The results are shown in Table 2. The cyclic conjugated compound is prepared by dispersing any cyclic conjugated compound using a sand mill in the same manner as in the above step (3) while adjusting the dispersion conditions (dispersion time) so that the peak ratio becomes the ratio shown in the table.

[0067] [Table 2]

[0068] (Examples 17 to 19, Comparative Example 4) A photoelectric conversion element is prepared in the same manner as in Example 1, except for the type of cyclic conjugated compound, the presence or absence of addition of a resin solution when preparing the charge transport layer solution, the type of resin solution, the amount of resin solution, and not forming a second charge transport layer. The results are shown in Table 3. The cyclic conjugated compound is prepared by dispersing any cyclic conjugated compound using a sand mill in the same manner as in the above step (3) while adjusting the dispersion conditions (dispersion time) so that the peak ratio becomes the ratio shown in the table.

[0069] [Table 3]

[0070] The disclosure of this embodiment includes the following configuration. [Configuration 1] A photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer containing a crystal of a cyclic conjugated compound in which a plurality of pyrrole rings are conjugatedly bonded; A photoelectric conversion element characterized in that, in a scanning range of 3.0° to 30.0° of Bragg angle 2θ in an X-ray diffraction spectrum using CuKα radiation of the charge transport layer, when the peak with the maximum intensity among peaks present in the range of 5.0° to 8.0° is defined as peak α and the peak with the maximum intensity among peaks present in the range of 26.0° to 29.0° is defined as peak β, either peak α or peak β is the peak with the maximum intensity in the scanning range, and when the intensity of peak α is defined as Iα and the intensity of peak β is defined as Iβ, Iα / Iβ is 2.0 or less. [Configuration 2] 2. The photoelectric conversion element according to claim 1, wherein the Iα / Iβ is 1.0 or less. [Configuration 3] 3. The photoelectric conversion element according to configuration 1 or 2, wherein the photoelectric conversion element has a second charge transport layer between the first electrode and the charge transport layer. [Configuration 4] 4. The photoelectric conversion element according to any one of configurations 1 to 3, wherein the charge transport layer contains a resin. [Configuration 5] 5. The photoelectric conversion element according to configuration 4, wherein the content of the resin in the charge transport layer is 3% by mass to 30% by mass with respect to the content of the cyclic conjugated compound. [Configuration 6] 6. The photoelectric conversion element according to any one of configurations 1 to 5, wherein the cyclic conjugated compound is a phthalocyanine compound. [Configuration 7] 7. The photoelectric conversion element according to configuration 6, wherein the phthalocyanine compound is a titanyl phthalocyanine compound or a gallium phthalocyanine compound. [Configuration 8] 8. The photoelectric conversion element according to claim 7, wherein the phthalocyanine compound is a gallium phthalocyanine compound. [Configuration 9] 9. The photoelectric conversion element according to configuration 8, wherein the gallium phthalocyanine compound is a hydroxygallium phthalocyanine compound. [Configuration 10] 10. The photoelectric conversion element according to any one of configurations 1 to 9, wherein the peak α is in the range of 7.2° to 7.6°, and the peak β is in the range of 28.0° to 28.4°. [Explanation of symbols]

[0071] 1 Cyclic conjugated compound molecules 2. Crystal structure of the cyclic conjugated compound according to the example 3. Crystal structure of a cyclic conjugated compound for comparison 4. Board 5 Second electrode 6 Electron transport layer 7 Photoelectric conversion layer 8 Charge transport layer 9 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 photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer containing a crystal of a cyclic conjugated compound in which a plurality of pyrrole rings are conjugatedly bonded; A photoelectric conversion element characterized in that, in a scanning range of 3.0° to 30.0° of Bragg angle 2θ in an X-ray diffraction spectrum using CuKα radiation of the charge transport layer, when the peak with the maximum intensity among peaks present in a range of 5.0° to 8.0° is defined as peak α and the peak with the maximum intensity among peaks present in a range of 26.0° to 29.0° is defined as peak β, either peak α or peak β is the peak with the maximum intensity in the scanning range, and when the intensity of peak α is defined as Iα and the intensity of peak β is defined as Iβ, Iα / Iβ is 2.0 or less.

2. 2. The photoelectric conversion element according to claim 1, wherein the Iα / Iβ is 1.0 or less.

3. The photoelectric conversion element according to claim 1 , further comprising a second charge transport layer between the first electrode and the charge transport layer.

4. The photoelectric conversion element according to claim 1 , wherein the charge transport layer contains a resin.

5. The photoelectric conversion element according to claim 4 , wherein the content of the resin in the charge transport layer is 3% by mass to 30% by mass with respect to the content of the cyclic conjugated compound.

6. 2. The photoelectric conversion element according to claim 1, wherein the cyclic conjugated compound is a phthalocyanine compound.

7. The photoelectric conversion element according to claim 6 , wherein the phthalocyanine compound is a titanyl phthalocyanine compound or a gallium phthalocyanine compound.

8. The photoelectric conversion element according to claim 7 , wherein the phthalocyanine compound is a gallium phthalocyanine compound.

9. The photoelectric conversion element according to claim 8 , wherein the gallium phthalocyanine compound is a hydroxygallium phthalocyanine compound.

10. 2. The photoelectric conversion element according to claim 1, wherein the peak α is within a range of 7.2° to 7.6°, and the peak β is within a range of 28.0° to 28.4°.

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