Photoelectric conversion element, photoelectric conversion device, and method for manufacturing photoelectric conversion element

Abstract

To provide a photoelectric conversion element that improves photoelectric conversion efficiency.SOLUTION: A photoelectric conversion element has a first electrode, a second electrode, and a photoelectric conversion layer arranged between the first electrode and the second electrode and including a crystal of a perovskite structure. The photoelectric conversion element has a charge transport layer arranged between the photoelectric conversion layer and the first electrode. The charge transport layer is formed of charge transporting particles and insulating resin on a surface of the photoelectric conversion layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element, a photoelectric conversion device, and a method for manufacturing a photoelectric conversion element. [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 sheet-shaped substrates, which is expected to reduce costs. However, further improvement in power generation efficiency and durability is 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 characteristics, so development is being advanced toward practical use of solar cells. For example, Patent Document 1 describes a technology that improves peeling from the electrode by including an organic semiconductor and a polymer compound with a glass transition temperature of 100°C or higher in the hole transport layer. Non-Patent Document 1 describes that conversion efficiency is improved by mixing copper phthalocyanine and a conductive polymer in the hole transport layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-170382 A [Non-patent literature]

[0006] [Non-Patent Document 1] Q. Hu,et al,Sol.RRL,2019,3,1800264 Summary of the Invention [Problem to be solved by the invention]

[0007] According to the studies of the present inventors, it has been found that the photoelectric conversion elements described in Patent Document 1 and Non-Patent Document 1 have room for improvement in photoelectric conversion efficiency. Therefore, an object of the present invention is to provide a photoelectric conversion element having improved photoelectric conversion efficiency. Another object of the present invention is to provide a photoelectric conversion device having improved photoelectric conversion efficiency. Or, an object of the present invention is to provide a manufacturing method for a photoelectric conversion element having improved photoelectric conversion efficiency. [Means for solving the problem]

[0008] The above object can be achieved by the present invention. A first electrode; 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 charge transport layer is disposed between the photoelectric conversion layer and the first electrode; The photoelectric conversion element has a charge transport layer formed on the surface of the photoelectric conversion layer from charge transport particles and an insulating resin. The present invention also relates to a photoelectric conversion device including the photoelectric conversion element. The present invention also provides a method for producing a semiconductor device comprising the steps of: forming a first electrode; forming a second electrode; forming a photoelectric conversion layer including a crystal having a perovskite structure between the first electrode and the second electrode; forming a charge transport layer between the photoelectric conversion layer and the first electrode; A method for producing a photoelectric conversion element comprising: The method for producing a photoelectric conversion element includes forming the charge transport layer on the surface of the photoelectric conversion layer, the charge transport layer including charge transport particles and an insulating resin. Effect of the Invention

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

[0010] [Figure 1] 1 is a schematic diagram of a layer structure in a thickness direction of a first embodiment of a photoelectric conversion element of the present invention. [Diagram 2] 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; [Diagram 3] 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. [Figure 4] 1 is a schematic cross-sectional view of one embodiment of a photoelectric conversion element of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <First embodiment> The first embodiment relates to a photoelectric conversion element. The photoelectric conversion element of the present invention comprises: A first electrode; 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 charge transport layer is disposed between the photoelectric conversion layer and the first electrode; The charge transport layer is formed on the surface of the photoelectric conversion layer from charge transport particles and an insulating resin. As a result of investigations, the present inventors have found that the inclusion of the above-mentioned charge transport layer results in a photoelectric conversion element with excellent conversion efficiency. The reasons for this are believed to be as follows.

[0012] The photoelectric conversion layer made of crystals with a perovskite structure has unevenness on the crystal surface. In addition, there may be gaps between the crystal grains. If oxygen or the like is present in these unevenness or gaps, deterioration will progress easily, so it is preferable to fill them with a charge transport layer or the like. However, when a low-resistance charge transport layer is formed on the surface of the photoelectric conversion layer made of crystals with a perovskite structure, the surface on the side of the unevenness or gap against the flow of charge will be covered with a low-resistance material. As a result, the electrons and holes are easily recombined, and the photoelectric conversion efficiency may decrease. In addition, when a high-resistance charge transport layer is formed on the surface of the photoelectric conversion layer made of crystals with a perovskite structure, the exchange of charges is hindered, and the conversion efficiency of the photoelectric conversion element may decrease.

[0013] On the other hand, when a charge transport layer is formed on a crystal having a perovskite structure using charge transport particles and an insulating resin, the charge transport particles and the insulating resin exist independently, and as a result, the insulating resin preferentially penetrates into the side surfaces of the unevenness and gaps of the crystal having a perovskite structure, suppressing the recombination of electrons and holes that occurs there.

[0014] At the same time, it is believed that the charge transport efficiency from the perovskite crystal to the first electrode is maintained without the insulating resin interfering with charge transport because the charge transport material is present as particles on the perovskite crystal.

[0015] <Charge transport particles> In the present invention, the average particle size of the charge transport particles is 1.0×10 1 nm or more 3.0×10 2nm or less. Within the above range, the charge transport particles can be prevented from penetrating between the perovskite crystal grains, and the uniformity of the film can be maintained, so that the loss of charge transport properties can be suppressed. The particle size of the charge transport particles contained in the charge transport layer can be determined as the volume average particle size from the particle size distribution determined by an image imaging method using a scanning electron microscope (SEM). Specific examples of materials for the charge transporting particles include phthalocyanine pigments, azo pigments, lake pigments, quinacridone pigments, dioxazine pigments, perylene pigments, and isoindolinone pigments.

[0016] In the present invention, the charge transporting particles are preferably particles containing a cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings. By forming the cyclic conjugated compound formed by covalently bonding a plurality of pyrrole rings into charge transporting particles, the charge transporting particles exhibit high charge transporting ability. In the present invention, the charge transporting particles are preferably particles containing a phthalocyanine compound, and more preferably particles having a structure represented by the following formula (Pc-2). The charge transporting particles can more efficiently transport charges generated in the photoelectric conversion layer. [ka] (M in the above formula (Pc-2) is H 2 , a metal atom having a ligand, or a metal atom having no ligand. The structure of chemical substances such as the charge transport particles of the present invention can be confirmed by a nuclear magnetic resonance (NMR) method.

[0017] In particular, M in the above formula (Pc-2) is H 2 When this is the case, the above formula (Pc-2) is represented by the following formula (Pc-1). [ka]

[0018] Specific examples of insulating resins include polyacetal resins, acrylic resins, polyarylate resins, polycarbonate resins, polyvinyl acetate resins, polyester resins, polyamide resins, polyurethane resins, and polystyrene resins.

[0019] In the present invention, the insulating resin preferably has a glass transition temperature of 95° C. or less. Within this range, the insulating resin can easily come into intimate contact with the charge transport material (charge transport particles), and a more effective charge distribution can be formed. The glass transition temperature can be determined by a differential scanning calorimeter (DSC).

[0020] In the present invention, the insulating resin is preferably a polyvinyl acetal resin or a polyvinyl butyral resin, which is easily in close contact with the charge transport material (charge transport particles) and can form a more effective charge distribution.

[0021] In the present invention, the charge transport layer preferably contains an aromatic ring compound having a hydroxyl group, which is different from the charge transport material (charge transport particles) and the insulating resin. By containing the aromatic ring compound having a hydroxyl group, the charge transport material (charge transport particles) and the insulating resin can be more easily contacted with each other, and a more effective charge distribution can be formed.

[0022] In the present invention, the photoelectric conversion element may have a second charge transport layer between the first electrode and the charge transport layer. By having the second charge transport layer, the transfer of carriers to the electrode may be facilitated.

[0023] As explained above, the respective components exert a synergistic effect on each other, thereby making it possible to achieve the effects of the present invention. 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.

[0024] 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 a layer can be performed, for example, by performing TOF-SIMS / FE-TEM / EDS line analysis measurement of a cross section of a photoelectric conversion element to confirm the element distribution of a specific element. Analysis of each layer may be performed by peeling and removing the completed photoelectric conversion element to expose the layer to be analyzed. In the present invention, the volume ratio is quantified by using the area ratio of the exposed surface or cross section as the volume ratio of the layer.

[0025] 1 is a cross-sectional view showing a schematic configuration of one embodiment of a photoelectric conversion element of the present invention. The photoelectric conversion element 1 has a second electrode 3, an electron transport layer 4, a photoelectric conversion layer 5, a charge transport layer 6, and a first electrode 7 on a substrate 2. One of the first electrode 7 and the second electrode 3 is an anode and the other is a cathode, and a current can be extracted by connecting the first electrode 7 and the second electrode 3 to an external circuit.

[0026] 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 two electrodes (the second electrode 3 and the first electrode 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 laminated may be used. Such a form may also be called a tandem structure. Each member will be described below. In addition, 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.

[0027] [Photoelectric conversion element] The photoelectric conversion element of the present invention is characterized by having a first electrode, a second electrode, a photoelectric conversion layer containing a crystal of a perovskite structure disposed between the first electrode and the second electrode, and a charge transport layer 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 perovskite crystal in the photoelectric conversion layer, a silicon solar cell, a CIGS solar cell, and the like.

[0028] 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. Each layer will be described below.

[0029] 〔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, a transparent plastic substrate, etc. 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.

[0030] 〔electrode〕 The photoelectric conversion element of the present invention has a first electrode and a second electrode. The materials of the first electrode 7 and the second electrode 3 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 / Al 2 O3 Examples of transparent electrode materials include CuI, ITO (indium tin oxide), SnO 2 Examples of the conductive transparent material include AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), FTO (fluorine-doped tin oxide), ATO (antimony-doped tin oxide), and conductive transparent polymers. These materials may be used alone or in combination of two or more. The first electrode 7 and the second electrode 3 are such that at least one electrode on the light incident side is a transparent electrode, and the other may be a transparent electrode or a layer 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 electrodes may be patterned electrodes.

[0031] [Photoelectric Conversion Layer] The photoelectric conversion element of the present invention has a photoelectric conversion layer including a crystal having a perovskite structure, which is disposed between a first electrode and a second electrode. 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]. ABX 3 [1]

[0032] 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. As A in the above general formula [1], for example, in the case of an organic molecule, C p N m H n (wherein p, m, and n are all positive integers) are preferred. 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.

[0033] 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 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.

[0034] The crystals having a two-dimensional perovskite or 2.5-dimensional perovskite structure are preferably represented by the following general formulas [2] to [4], in which n is a positive integer. R' 2 A n-1 B n X 3n+1 [2] R''A n-1 B n X 3n+1 [3] R'''A n B n X 3n+1 [4]

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 and the like. Furthermore, iodine is more preferred because the energy band gap of the perovskite crystals is narrowed.

[0039] Specifically, 3D perovskites, 2D perovskites, and mixed 3D / 2D perovskites are synthesized using MAPbI 3 or FAPbCl 3 , FAPbI 3 , 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 , (FAPbI 3 )0.95 (MAPbBr 3 ) 0.05 、(FAPbI 3 ) 0.85 (MAPbBr 3 ) 0.15 、CsPbI 3 、CsPbBr 3 、Cs x (MA) 1-x PbI 3 、Csx(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 、(PEA) 2 (MA) 2 Pb 3 I 10 、(PTA) 2 (MA) 4 Pb 5 I 16 、(PEA) 2 (MA) 4 Pb 5 I 16 、(ThMA) 2 (MA) 2 Pb 3 I 10 、(3BBA) 2 (MA) 2 Pb 3 I 10 、(ThMA) 2 (FA) 4 Pb 5 I 16 、(pF-PEA) 2 (FA 0.3 MA0.7 ) 4 Pb 5 I 16 、(PDMA)FA 2 Pb 3 I 10 、(3AMPY)(MA) 3 Pb 4 I 13 、(PDMA)MA 5 Pb 6 I 19 、(PDMA)MA 3 Pb 4 I 13 、(TTDMA)MA 3 Pb 4 I 13 、(TTDMA)MA 4 Pb 5 I 16 、(BA 0.9 PEA 0.1 ) 2 MA 4 Pb 5 I 16 、(BA 0.9 PEA 0.1 ) 2 MA 3 Pb 4 I 13 、(4FPEA) 2 MA 3 Pb 4 I 13 、(4FPEA) 2 MA 4 Pb 5 I 16 (BA) 2 MA 2 Pb 3 I 10 、(BA) 2 MA 3 Pb 4 I 13 、(TEA) 2 MA 2 Pb 3 I 10 、(BA) 2 MA 4 Pb 5 I 16 、(BA) 2 MA 3 Pb 4 I 13 、CsSnBr3 , CsSnI 3 , F.A. 0.75 MA 0.25 Sn 0.95 Ge 0.05 I 3 , FAMASnGeI 3 , FASnBr 3 , FASnI 3 , M.A. 2 Sn 3 I 8 , MASnBr 3 , MASnGeI 3 , MASnI 3 is preferable. Depending on the purpose, the A site, B site, or X site in the above general formula may be adjusted to be under- or over-adjusted, and the combination of x1 to x5 may be changed depending on the purpose. Combinations of x1 to x5 are, for example, as shown in Table 1. Particularly preferable 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.

[0040] [Table 1]

[0041] 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.

[0042] 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.

[0043] The organic-inorganic perovskite compound 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 organic-inorganic perovskite compound as a crystalline semiconductor, the mobility of electrons in the organic-inorganic perovskite compound is increased, and the photoelectric conversion efficiency of the photoelectric conversion element is improved. Furthermore, the photoelectric conversion layer according to the present invention may contain materials other than the crystals having the organic-inorganic perovskite structure, as long as the photoelectric conversion efficiency and charge transport properties are not impaired.

[0044] 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 or more, 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.

[0045] In the present invention, the surface roughness Ra of the perovskite crystal of the photoelectric conversion layer is preferably 10 nm or more and 200 nm or less. When the surface roughness Ra is 10 nm or more, the recombination suppression effect of the insulating resin is more likely to be exhibited. When the surface roughness Ra is larger than 200 nm, the charge transporting particles are more likely to penetrate to the second electrode side of the photoelectric conversion layer, and the recombination suppression effect may be reduced.

[0046] [Charge transport layer] In the photoelectric conversion element of the present invention, a charge transport layer is disposed between a photoelectric conversion layer and a first electrode, and the charge transport layer is formed on the surface of the photoelectric conversion layer from charge transport particles and an insulating resin. In the photoelectric conversion element of the present invention, it is preferable that the insulating resin is disposed between the crystals of the perovskite structure of the photoelectric conversion layer. The charge transport particles, insulating resin, and other items are as described above.

[0047] In the present invention, the charge transport layer contains charge transport particles that are P-type semiconductors and an insulating resin, and the volume of the charge transport particles in the charge transport layer is preferably 5 to 30 times the volume of the insulating resin in the charge transport layer. 8 Ω·cm or more.

[0048] 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.

[0049] 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.

[0050] [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.

[0051] 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.

[0052] [Electron transport layer] In the photoelectric conversion element of the present invention, as shown in FIG. 1, 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 organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surfactants, etc. Specific examples thereof include cyano group-containing polyphenylene vinylene, boron-containing polymers, bathocuproine, bathophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic 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, zinc sulfide, etc. In particular, tin oxide may be obtained by reacting tin chloride (2), tin chloride (4), tin chloride (2) dihydrate, or tin chloride (4) pentahydrate.

[0053] 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 of the electron transport layer 4 is 1 nm or more, holes can be blocked sufficiently, and if it is 2000 nm or less, it is unlikely to become a resistance during electron transport, and the photoelectric conversion efficiency is high. 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.

[0054] [Control of particle size of charge transport particles] The particle size of the charge transport particles can be changed by dispersing the charge transport layer coating liquid with a paint shaker, and the particle size can be reduced by extending the dispersion time, and the particle size can be further reduced by centrifuging the charge transport layer coating liquid.

[0055] <Application Examples> Application examples of the present invention include photoelectric conversion devices, moving objects, and building materials. [Photoelectric conversion device] The photoelectric conversion device of the present invention has the above-mentioned photoelectric conversion element. A photoelectric conversion device can be configured by using a plurality of photoelectric conversion elements of the present invention. When a plurality of photoelectric conversion elements are connected, the 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 photoelectric conversion elements having 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 or the like, an all-solid-state battery, an electric double layer capacitor, etc. may 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.

[0056] [Mobile object] The moving body of the present invention has the above-mentioned photoelectric conversion element. FIG. 2 is a perspective view showing an embodiment of a moving body equipped with the photoelectric conversion element of the present invention. The moving body 30 has the 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 arranged at a position where the vehicle 32 can receive external light. If the moving body 30 is an automobile, it may be arranged on the roof. The electric energy obtained by the photoelectric conversion element 31 may be used as the power of the moving body 30 or as the power of other electric devices. The electric energy generated from the power of the moving body 30 may be used to power the photoelectric conversion element 31. If the moving body 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.

[0057] [Building materials] The building material of the present invention has the above-mentioned photoelectric conversion element. Fig. 3 is a perspective view showing an embodiment of a building material including the 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 the 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.

[0058] 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.

[0059] 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.

[0060] In addition to the above application examples, other application examples include the following: Portable devices, such as calculators, sensors, and small solar panels. Wearable devices, such as eyeglass-type terminals, wristwatch-type terminals, and portable medical equipment. Sheet structures supported by multiple frames, such as tents, vinyl greenhouses, and truck beds. Fixed structures, such as 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.

[0061] <Second embodiment> The second embodiment relates to a method for manufacturing a photoelectric conversion element. The method for producing a photoelectric conversion element of the present invention includes the steps of: forming a first electrode; forming a second electrode; forming a photoelectric conversion layer including a crystal having a perovskite structure between the first electrode and the second electrode; forming a charge transport layer between the photoelectric conversion layer and the first electrode; A method for producing a photoelectric conversion element comprising: The charge transport layer contains charge transport particles and an insulating resin and is formed on the surface of the photoelectric conversion layer. Each substance and material is the same as in the first embodiment, and therefore the description will be omitted.

[0062] As a result of investigations, the present inventors have found that the use of the above-mentioned manufacturing method makes it possible to obtain a photoelectric conversion element having excellent conversion efficiency. The reasons for this are believed to be as follows. The photoelectric conversion layer made of crystals with a perovskite structure has unevenness on the crystal surface. In addition, there may be gaps between the crystal grains. If oxygen or the like is present in these gaps, deterioration will progress easily, so it is preferable to fill them with a charge transport layer or the like. However, when a low-resistance charge transport layer is formed on the surface of the photoelectric conversion layer made of crystals with a perovskite structure, the surface on the side of the unevenness or gap will be covered with a low-resistance material against the flow of charge. As a result, the electrons and holes are easily recombined, and the conversion efficiency of the photoelectric conversion element may decrease. In addition, when a high-resistance charge transport layer is formed on the surface of the photoelectric conversion layer made of crystals with a perovskite structure, the exchange of charges is hindered, and the conversion efficiency of the photoelectric conversion element may decrease.

[0063] On the other hand, when a charge transport layer is formed on a perovskite crystal using charge transport particles and an insulating resin, the charge transport particles and the insulating resin exist independently, and therefore the insulating resin preferentially penetrates into the side surfaces of the unevenness and gaps of the crystal with the perovskite structure, suppressing the recombination of electrons and holes that occurs there.

[0064] At the same time, it is believed that the charge transport efficiency from the perovskite crystal to the first electrode is maintained without the insulating resin interfering with charge transport because the charge transport material is present as particles on the perovskite crystal.

[0065] <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.

[0066] When manufacturing solar cells, cutting is generally performed between each process to form circuits. Examples of cutting include mechanical patterning and laser patterning.

[0067] <Modularization process> The method for producing a photoelectric conversion element of the present invention may include a modularization step of sealing the element having the electrodes formed thereon. Examples of the sealing method include sealing with a resin or sealing with a film. Examples of materials used for sealing include silazane, silicone rubber, resins 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.

[0068] <Step of forming photoelectric conversion layer> The method for producing a photoelectric conversion element of the present invention includes a step of forming a photoelectric conversion layer containing a crystal of a perovskite structure between a first electrode and a second electrode. The step of forming the photoelectric conversion layer includes 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, print 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.

[0069] 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.

[0070] <Step of forming charge transport layer> The method for producing a photoelectric conversion element of the present invention includes a step of forming a charge transport layer between the photoelectric conversion layer and the first electrode. The charge transport layer contains charge transport particles and an insulating resin and is formed on the surface of the photoelectric conversion layer. The step of forming the charge transport layer is preferably a method of applying a resin solution in which an insulating resin is dissolved, which allows the insulating resin to preferentially infiltrate into the gaps between the perovskite crystal grains. Examples of the step of forming the charge transport layer include a method of disposing charge transport particles on the surface of the photoelectric conversion layer and then applying a resin solution in which an insulating resin is dissolved. Alternatively, a method of applying a resin solution in which an insulating resin is dissolved on the surface of the photoelectric conversion layer and then disposing charge transport particles. Alternatively, a method of applying a solution in which charge transport particles are dispersed in a resin solution in which an insulating resin is dissolved on the surface of the photoelectric conversion layer. EXAMPLES

[0071] 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 based on mass unless otherwise specified.

[0072] Example 1 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 4.5 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%.

[0073] 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. At this time, 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 in a Hyper Dry dryer (product name: HD-06R, frequency (oscillation frequency): 2455 MHz ± 15 MHz, manufactured by Japan Biocon) to obtain hydroxygallium phthalocyanine (OHGaPc) particles (crystals) with a moisture content of 1.0 mass% or less.

[0074] Process (3) Five parts of the hydroxygallium phthalocyanine particles were mixed with 5 parts of N-methylformamide solvent, and the mixture was dispersed for 6 hours using a sand mill (TSG-1 / 4G-4U, manufactured by Igarashi Machinery Manufacturing (now Imex), disk diameter 70 mm, number of disks 5) containing 5 parts of glass beads, filtered, and dried to obtain Particle 1 (specific gravity 1.6).

[0075] Preparation of resin solution 1 1.0 g of polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd., specific gravity 1.6) was dissolved in 19 g of 2-propanol with stirring for 24 hours to obtain resin solution 1.

[0076] [Formation of Electron Transport Layer] A square ITO-coated glass substrate with sides of 25 mm was cleaned, and a 5-fold diluted tin oxide (2) colloidal solution (15% water dispersion, manufactured by Alfa Aesar) was spin-coated onto it, followed by heating at 150°C for 30 minutes to form a thin-film electron transport layer with a thickness of 16 nm.

[0077] [Formation of photoelectric conversion layer] 0.487 g of lead bromide, 1.034 g of formamidium iodide, 2.903 g of lead iodide, and 0.139 g of methylammonium bromide were dissolved in 4.25 g of N,N-dimethylformamide and 1.216 g of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 1). Furthermore, 0.100 g of cesium iodide was dissolved in 0.285 g of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 2). The dissolved cesium iodide solution (solution 2) was then added to solution 1 to prepare a photoelectric conversion layer coating solution. This coating solution was spin-coated on the electron transport layer using the poor solvent method, resulting in the formation of a photoelectric conversion layer containing Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 ) 3 A photoelectric conversion layer having a thickness of 600 nm and a surface roughness Ra of 13 nm was formed.

[0078] [Formation of Charge Transport Layer] 0.1g of the particles 1 and 0.01g of a calixarene compound (JP Patent Publication 2003-207913) were mixed with 10.6g of 2-propanol, and 11g of beads (zirconia beads, Treceram (registered trademark) zirconia beads, 0.3mm) were encapsulated in this mixture, and dispersion was performed using a paint shaker (manufactured by Toyo Seiki) for 7 hours. Then, 0.2g of resin solution 1 was added, and dispersion was performed again using a paint shaker for 6 hours to prepare a charge transport layer solution. This charge transport layer solution was spin-coated on the photoelectric conversion layer to form a charge transport layer having a thickness of 160nm.

[0079] [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 4-tert-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(3)tris(bis(trifluoromethylsulfonyl)imide)] in 0.3 g of acetonitrile was mixed to prepare a material 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 100 nm.

[0080] [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 Gold electrodes were formed at 10 locations by vacuum deposition to obtain a photoelectric conversion element.

[0081] [Analysis of compound amounts] The electrode surface of the photoelectric conversion element was peeled off to expose the charge transport layer surface. This charge transport layer surface was wiped with a cotton swab soaked in a solvent, dissolved in heavy water sulfuric acid, and 1H-NMR measurement (apparatus: AVANCE3-500, manufactured by BRUKER) was performed. In addition, the peeled off charge transport layer components were subjected to mass and structure analysis by elemental analysis such as GPC, MALDI-TOF-MS, IR, gas chromatography, XPS, and EDX to confirm the presence of compounds. 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).

[0082] [Measurement of particle size of charge transport particles] The particle size of the charge transporting particles contained in the charge transport layer is a volume average particle size determined from particle size distribution. In the present invention, the particle size distribution of the charge transporting particles was determined by an image imaging method using a transmission electron microscope (TEM). Specifically, first, the obtained TEM image of the cross section of the charge transport layer is used to extract N particles (N is 1000 or more) using image processing software Photoshop (manufactured by Adobe). Next, the area S of each particle is calculated, and the diameter of a circle with the same area as this area (= 2 × (S / π) 1 / 2 ) was used as the particle size, and the average value of the median 80% of the N particles was taken.

[0083] [Measurement of surface roughness Ra of photoelectric conversion layer] The surface roughness Ra of the photoelectric conversion layer is the roughness of the surface on the first electrode side. Examples of the measurement method include a method of measuring the photoelectric conversion layer after removing the first electrode and the charge transport layer from the photoelectric conversion element using an AFM / SPM, and a method of calculating from a cross-sectional image of the photoelectric conversion element. In this embodiment, the surface roughness Ra was calculated by image analysis of an atomic force microscope AFM / SPM (MFP-3D Origin, Oxford Instruments) that was used to obtain a height image in AM-FM mode. The measurement conditions were a cantilever OMCL-AC-160TS (Olympus), and a range of 90 μm × 90 μm was measured at a scanning frequency of 1 Hz. The number of X data points was 256, and the number of Y data points was 256.

[0084] Example 2 1 g of particles 1 obtained in the particle preparation process is mixed with 100 g of 2-propanol, 80 g of zirconia beads are enclosed in this mixture, and dispersion is performed for 6 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.) to prepare a particle dispersion. Next, the particle dispersion is centrifuged (15,000 rpm, 3 minutes) using a tabletop high-spin centrifuge (D3024, manufactured by DLAB) to reduce the particle size in the dispersion, and the particles are filtered and dried to obtain particles 2 with reduced particle size. A photoelectric conversion element is obtained in the same manner as in Example 1, except that particles 2 are used instead of particles 1 in the formation of the charge transport layer.

[0085] Example 3 1 g of particles 1 obtained in the particle preparation process is mixed with 100 g of 2-propanol, 80 g of zirconia beads are enclosed in this mixture, and dispersion is performed for 10 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.) to prepare a particle dispersion. Next, the particle dispersion is centrifuged (15,000 rpm, 5 minutes) to reduce the particle size in the dispersion, and the particles are filtered and dried to obtain particles 3 with reduced particle size. A photoelectric conversion element is obtained in the same manner as in Example 1, except that particles 3 are used instead of particles 1 in forming the charge transport layer.

[0086] Example 4 A photoelectric conversion element is obtained in the same manner as in Example 1, except that in forming the charge transport layer, the dispersion time in the paint shaker dispersion is changed from 6 hours to 4 hours to increase the particle size in the dispersion liquid.

[0087] Example 5 A photoelectric conversion element is obtained in the same manner as in Example 1, except that in forming the charge transport layer, the dispersion time in the paint shaker dispersion is changed from 6 hours to 2 hours to increase the particle size in the dispersion liquid.

[0088] Example 6 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the ratio of the volume of the charge transport material (charge transport particles) to the volume of the insulating resin is set to 3.

[0089] Example 7 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the ratio of the volume of the charge transport material (charge transport particles) to the volume of the insulating resin is set to 5.

[0090] Example 8 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the ratio of the volume of the charge transport material (charge transport particles) to the volume of the insulating resin is set to 20.

[0091] Example 9 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the ratio of the volume of the charge transport material (charge transport particles) to the volume of the insulating resin is set to 30.

[0092] Example 10 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the ratio of the volume of the charge transport material (charge transport particles) to the volume of the insulating resin is set to 35.

[0093] Example 11 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd.) is replaced with polyvinyl butyral (product name: BX-1, manufactured by Sekisui Chemical Co., Ltd.).

[0094] Example 12 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the particles 1 are nickel phthalocyanine particles.

[0095] (Example 13) A photoelectric conversion element is obtained in the same manner as in Example 1, except that the particles 1 are copper phthalocyanine particles.

[0096] Example 14 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the second charge transport layer is not provided.

[0097] Example 15 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the polyvinyl butyral is replaced with polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich, glass transition temperature 70° C.).

[0098] (Example 16) A photoelectric conversion element is obtained in the same manner as in Example 1, except that the polyvinyl butyral is replaced with polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich, glass transition temperature: 100° C.).

[0099] (Example 17) A photoelectric conversion element is obtained in the same manner as in Example 1, except that the particles 1 are particles having a compound represented by the following formula (Pc-3). [ka]

[0100] (Example 18) A photoelectric conversion element is obtained in the same manner as in Example 1, except that the particles 1 are quinacridone particles.

[0101] (Example 19) A photoelectric conversion element is obtained in the same manner as in Example 1, except that the particles 1 are changed to tetraphenylporphyrin (TPP).

[0102] (Example 20) A photoelectric conversion layer was formed without using the poor solvent method to obtain a photoelectric conversion element in Example 1. The surface roughness Ra of the photoelectric conversion layer was 122 nm.

[0103] Example 21 In Example 1, 3.85 g of N,N-dimethylformamide and 1.15 g of dimethyl sulfoxide were used, and a photoelectric conversion layer was formed without using the poor solvent method, to obtain a photoelectric conversion element. The surface roughness Ra of the photoelectric conversion layer was 212 nm.

[0104] Comparative Example 1 A photoelectric conversion element was obtained in the same manner as in Example 1, except that the particles 1 were not used in forming the charge transport layer.

[0105] Comparative Example 2 A photoelectric conversion element is obtained in the same manner as in Example 1, except that the insulating resin is not used.

[0106] Comparative Example 3 A photoelectric conversion element is obtained in the same manner as in Example 15, except that the particles 1 are SPIRO-OMeTAD. In addition, SPIRO-OMeTAD was not able to be observed as particles because it was compatible with PMMA resin.

[0107] Comparative Example 4 A photoelectric conversion element is obtained in the same manner as in Example 1, except that P3HT is used as the conductive resin instead of the insulating resin.

[0108] [evaluation] A power supply (KEITHLEY, Model 236) was connected between the electrodes of the photoelectric conversion element prepared in Example 1, and the intensity was 114 mW / cm 2 The photoelectric conversion efficiency was measured by irradiating a certain amount of light using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) and measuring the generated current and voltage. In addition, measurements were taken at 10 electrodes for each photoelectric conversion element, and the average value was used as the representative value for that photoelectric conversion element. The results are shown in Table 2. In Table 2, the photoelectric conversion efficiency in Example 1 is set to 100, and the ratio to this is shown as the conversion efficiency of each photoelectric conversion element.

[0109] [Table 2]

[0110] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) A first electrode; 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 charge transport layer is disposed between the photoelectric conversion layer and the first electrode; The charge transport layer is formed on the surface of the photoelectric conversion layer and is made of charge transport particles and an insulating resin. (Configuration 2) 2. The photoelectric conversion element according to configuration 1, wherein the surface roughness Ra of the crystal of the perovskite structure of the photoelectric conversion layer is 10 nm or more and 200 nm or less. (Configuration 3) 3. The photoelectric conversion element according to configuration 1 or 2, wherein the insulating resin is disposed between crystals of a perovskite structure of the photoelectric conversion layer. (Configuration 4) The average particle size of the charge transport particles in the charge transport layer is 1.0×10 1 nm or more 3.0×102 4. The photoelectric conversion element according to any one of configurations 1 to 3, wherein the thickness of the photoelectric conversion element is 10 nm or less. (Configuration 5) 5. The photoelectric conversion element according to any one of configurations 1 to 4, wherein the volume of the charge transporting particles in the charge transport layer is 5 to 30 times the volume of the insulating resin in the charge transport layer. (Configuration 6) 6. The photoelectric conversion element according to any one of configurations 1 to 5, wherein the charge transporting particles are particles containing a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated. (Configuration 7) 7. The photoelectric conversion element according to any one of configurations 1 to 6, wherein the insulating resin has a glass transition temperature of 95° C. or lower. (Configuration 8) The photoelectric conversion element according to any one of configurations 1 to 7, wherein the charge transporting particles are particles containing a phthalocyanine compound. (Configuration 9) The photoelectric conversion element according to any one of configurations 1 to 8, wherein the charge transporting particles are particles having a structure represented by the following formula (Pc-2): [ka] (M in the above formula (Pc-2) is H 2 , or a metal atom having a ligand, or a metal atom having no ligand. (Configuration 10) 10. The photoelectric conversion element according to any one of configurations 1 to 9, wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin. (Configuration 11) 11. The photoelectric conversion element according to any one of configurations 1 to 10, wherein the charge transport layer contains a pigment and an aromatic ring compound having a hydroxyl group, which is different from the insulating resin. (Configuration 12) 12. The photoelectric conversion element according to any one of configurations 1 to 11, further comprising a second charge transport layer between the first electrode and the charge transport layer. (Configuration 13) A photoelectric conversion device comprising the photoelectric conversion element according to any one of configurations 1 to 12. (Method 1) forming a first electrode; forming a second electrode; forming a photoelectric conversion layer including a crystal having a perovskite structure between the first electrode and the second electrode; forming a charge transport layer between the photoelectric conversion layer and the first electrode; A method for producing a photoelectric conversion element comprising: The charge transport layer contains charge transport particles and an insulating resin, and is formed on the surface of the photoelectric conversion layer. (Method 2) The method for producing a photoelectric conversion element according to method 1, wherein the surface roughness Ra of the perovskite crystal of the photoelectric conversion layer is 10 nm or more and 200 nm or less. (Method 3) The average particle size of the charge transport particles in the charge transport layer is 1.0×10 1 nm or more 3.0×10 2 3. The method for producing a photoelectric conversion element according to method 1 or 2, wherein the thickness of the photoelectric conversion element is equal to or less than nm. (Method 4) The method for producing a photoelectric conversion element according to any one of Methods 1 to 3, wherein the volume of the charge transporting particles in the charge transport layer is 5 to 30 times the volume of the insulating resin in the charge transport layer. (Method 5) 5. The method for producing a photoelectric conversion element according to any one of Methods 1 to 4, wherein the charge transporting particles are particles containing a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated. (Method 6) 6. The method for producing a photoelectric conversion element according to any one of Methods 1 to 5, wherein the insulating resin has a glass transition temperature of 95° C. or lower. (Method 7) 7. The method for producing a photoelectric conversion element according to any one of Methods 1 to 6, wherein the charge transporting particles are particles containing a phthalocyanine compound. (Method 8) The method for producing a photoelectric conversion element according to any one of Methods 1 to 7, wherein the charge transporting particles are particles having a structure represented by the following formula (Pc-2): [ka] (M in the above formula (Pc-2) is H 2 , or a metal atom having a ligand, or a metal atom having no ligand. (Method 9) 9. The method for producing a photoelectric conversion element according to any one of Methods 1 to 8, wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin. (Method 10) 10. The method for producing a photoelectric conversion element according to any one of Methods 1 to 9, wherein the charge transport layer contains a pigment and an aromatic ring compound having a hydroxy group, which is different from the insulating resin. (Method 11) 11. The method for producing a photoelectric conversion element according to any one of Methods 1 to 10, wherein a second charge transport layer is provided between the first electrode and the charge transport layer. [Explanation of symbols]

[0111] 1 Photoelectric conversion element 2. Board 3 Second electrode 4 Electron transport layer 5 Photoelectric conversion layer 6 Charge transport layer 7 First electrode 11 Perovskite crystals 12 Charge transporting particles 13. Insulating resin 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; 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 charge transport layer is disposed between the photoelectric conversion layer and the first electrode; The charge transport layer is formed on the surface of the photoelectric conversion layer from charge transport particles and an insulating resin.

2. 2. The photoelectric conversion element according to claim 1, wherein the surface roughness Ra of the crystal of the perovskite structure of the photoelectric conversion layer is 10 nm or more and 200 nm or less.

3. The photoelectric conversion element according to claim 1 , wherein the insulating resin is disposed between crystals of the perovskite structure of the photoelectric conversion layer.

4. The average particle size of the charge transport particles in the charge transport layer is 1.0×10 １ nm or more 3.0×10 ２ The photoelectric conversion element according to claim 1 , wherein the thickness of the photoelectric conversion element is equal to or less than nm.

5. 2. The photoelectric conversion element according to claim 1, wherein a volume of the charge transporting particles in the charge transport layer is 5 to 30 times a volume of the insulating resin in the charge transport layer.

6. 2. The photoelectric conversion element according to claim 1, wherein the charge transporting particles are particles containing a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated.

7. 2. The photoelectric conversion element according to claim 1, wherein the insulating resin has a glass transition temperature of 95° C. or lower.

8. The photoelectric conversion element according to claim 1 , wherein the charge transporting particles are particles containing a phthalocyanine compound.

9. 2. The photoelectric conversion element according to claim 1, wherein the charge transporting particles are particles having a structure represented by the following formula (Pc-2): 【Chemistry 1】 (M in the above formula (Pc-2) is H ２ , or a metal atom having a ligand, or a metal atom having no ligand.

10. The photoelectric conversion element according to claim 1 , wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin.

11. The photoelectric conversion element according to claim 1 , wherein the charge transport layer contains an aromatic ring compound having a hydroxyl group, which is different from the pigment and the insulating resin.

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

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

14. forming a first electrode; forming a second electrode; forming a photoelectric conversion layer including a crystal having a perovskite structure between the first electrode and the second electrode; forming a charge transport layer between the photoelectric conversion layer and the first electrode; A method for producing a photoelectric conversion element comprising: The charge transport layer contains charge transport particles and an insulating resin, and is formed on the surface of the photoelectric conversion layer.

15. The method for producing a photoelectric conversion element according to claim 14 , wherein the surface roughness Ra of the crystal of the perovskite structure of the photoelectric conversion layer is 10 nm or more and 200 nm or less.

16. The average particle size of the charge transport particles in the charge transport layer is 1.0×10 １ nm or more 3.0×10 ２ The method for producing a photoelectric conversion element according to claim 14, wherein the thickness of the photoelectric conversion element is 1 nm or less.

17. The method for producing a photoelectric conversion element according to claim 14 , wherein a volume of the charge transporting particles in the charge transport layer is 5 to 30 times a volume of the insulating resin in the charge transport layer.

18. The method for producing a photoelectric conversion element according to claim 14 , wherein the charge transporting particles are particles containing a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated.

19. The method for producing a photoelectric conversion element according to claim 14 , wherein the insulating resin has a glass transition temperature of 95° C. or lower.

20. The method for producing a photoelectric conversion element according to claim 14 , wherein the charge transporting particles are particles containing a phthalocyanine compound.

21. The method for producing a photoelectric conversion element according to claim 14, wherein the charge transporting particles are particles having a structure represented by the following formula (Pc-2): 【Chemistry 2】 (M in the above formula (Pc-2) is H ２ , or a metal atom having a ligand, or a metal atom having no ligand.

22. The method for producing a photoelectric conversion element according to claim 14, wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin.

23. The method for producing a photoelectric conversion element according to claim 14 , wherein the charge transport layer contains an aromatic ring compound having a hydroxy group, which is different from the pigment and the insulating resin.

24. The method for producing a photoelectric conversion element according to claim 14 , further comprising a second charge transport layer between the first electrode and the charge transport layer.

Images