Photoelectric conversion element, photoelectric conversion device, movable body, and building material

Abstract

To provide a photoelectric conversion element improved in 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, between the photoelectric conversion layer and the first electrode, a charge transport layer containing a phthalocyanine crystal. In an X-ray diffraction spectrum using a CuKα ray for the phthalocyanine crystal, a peak is present within a range in which the Bragg angle 2θ is 28.0° or more and 29.0° or less. A lattice spacing d1 nm calculated from the value of 2θ of the peak satisfies 0.3100≤d1≤0.3160.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element, a photoelectric conversion device, a moving body, and a building material. [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, it has been reported that perovskite-type solar cells have problems with durability as solar cells, such as destruction of perovskite crystals due to the intrusion of moisture in the air and migration of ions from each layer into other layers. In order to solve this problem, research is being actively conducted on forming a layer around the photoelectric conversion layer to improve durability.

[0005] Patent Document 1 describes a technique for improving the photoelectric conversion efficiency and durability of a solar cell by forming a compound layer having a compound with a phthalocyanine skeleton in a hole transport layer. Patent Document 2 describes an improvement in photoelectric conversion efficiency (hereinafter also referred to as "PCE") by forming a layer containing a phthalocyanine compound between a hole transport layer (hereinafter also referred to as "charge transport layer") and a perovskite. Non-Patent Document 1 describes an improvement in conversion efficiency by including copper phthalocyanine in a hole transport layer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-149805 A [Patent Document 2] Patent Publication No. 2022-168820 [Non-patent literature]

[0007] [Non-Patent Document 1] F.Wang,et al,J.Phys.Chem.C 2017,121,3,1562 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in order to put the above conventional techniques to practical use, it was necessary to achieve a further improvement in conversion efficiency. It is therefore an object of the present invention to provide a photoelectric conversion element having improved conversion efficiency. It is also an object of the present invention to provide a photoelectric conversion device, a mobile object, and a building material each having the photoelectric conversion element. [Means for solving the problem]

[0009] The above object can be achieved by the present invention. A photoelectric conversion element having a first electrode, a second electrode, and 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, the photoelectric conversion element has a charge transport layer containing a phthalocyanine crystal between the photoelectric conversion layer and the first electrode, In an X-ray diffraction spectrum of the phthalocyanine crystal using CuKα radiation, a peak exists within a range of a Bragg angle 2θ of 28.0° or more and 29.0° or less, The lattice spacing d1 [nm] calculated from the 2θ value of the peak is 0.3100≦d1≦0.3160 The photoelectric conversion element is characterized in that: The present invention also provides a photoelectric conversion device having the above-described photoelectric conversion element. The present invention also relates to a moving object having the above-described photoelectric conversion element. The present invention also relates to a building material having the above-described photoelectric conversion element. Effect of the Invention

[0010] According to the present invention, it is possible to provide a photoelectric conversion element with improved conversion efficiency. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view in a thickness direction of an example of an embodiment of a photoelectric conversion element of the present invention. [Diagram 2] FIG. 4 is a schematic cross-sectional view in the thickness direction of another example of the photoelectric conversion element according to the embodiment of the present invention. [Diagram 3] 1 is a perspective view showing a schematic diagram of an embodiment of a moving body including a photoelectric conversion element of the present invention; [Figure 4] FIG. 1 is a perspective view 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

[0012] <One embodiment> One embodiment of the present invention relates to a photoelectric conversion element. The photoelectric conversion element of the present invention comprises: A photoelectric conversion element having a first electrode, a second electrode, and 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, the photoelectric conversion element has a charge transport layer containing a phthalocyanine crystal between the photoelectric conversion layer and the first electrode, In an X-ray diffraction spectrum of the phthalocyanine crystal using CuKα radiation, a peak exists within a range of a Bragg angle 2θ of 28.0° or more and 29.0° or less, The lattice spacing d1 [nm] calculated from the 2θ value of the peak is 0.3100≦d1≦0.3160 The present invention is characterized in that:

[0013] According to Patent Document 2, when the photoelectric conversion layer contains crystals with a perovskite structure, submicron unevenness occurs on the surface. It is presumed that filling the concave portions of such unevenness with pigment particles made of phthalocyanine crystals stabilizes the interfacial bond with the electrode, and high photoelectric conversion efficiency can be obtained. However, it was found that this alone is insufficient to obtain a higher photoelectric conversion efficiency.

[0014] As a result of investigations by the present inventors, the phthalocyanine crystal of the present invention has a peak in an X-ray diffraction spectrum using CuKα radiation, in which the Bragg angle 2θ is in the range of 28.0° to 29.0°, and the lattice spacing d1 [nm] calculated from the value of 2θ of the peak is 0.3100≦d1≦0.3160 It has been found that the photoelectric conversion efficiency can be further improved by keeping the temperature within the range of 100° C. to 150° C.

[0015] The reason why high photoelectric conversion efficiency can be obtained in the present invention is not clear in detail, but the present inventors speculate as follows. Phthalocyanine molecules are known to be flat, with their π orbitals extending in a direction perpendicular to the molecular plane (molecular axis direction) (hereinafter also referred to as the "vertical direction"). Therefore, phthalocyanine crystals have a columnar structure in which the faces are stacked facing each other due to the intermolecular interactions of the π bonding properties of the planar molecules. In the phthalocyanine crystals, the peaks that exist in the range of the Bragg angle 2θ of 28.0° to 29.0° are considered to be due to the phthalocyanine crystals being stacked in the vertical direction between the charge generating layer and the first electrode (the molecular spacing is assumed to be about 3 Å based on the Bragg equation).

[0016] As mentioned above, vertical stacking is the direction in which the π electron clouds overlap, and therefore the smaller the lattice spacing d1, the stronger the overlap of the π electron clouds, which increases the efficiency of carrier transport within the film and improves the photoelectric conversion efficiency.

[0017] On the other hand, phthalocyanine crystals have the property of absorbing light and generating electric charges, and are widely known to be used as a material for generating photocarriers in electrophotographic photoreceptors, for example. When the photoelectric conversion element of the present invention is irradiated with light, the phthalocyanine crystals also absorb a portion of the light to generate electron pairs, which are expected to hinder the transport of carriers from the photoelectric conversion layer toward the first electrode. By increasing the lattice spacing d1, the efficiency of electron pair generation in the phthalocyanine crystals is reduced, and the efficiency of carrier transport is increased, thereby improving the photoelectric conversion efficiency.

[0018] Based on the above mechanism, the present inventors speculate that by controlling the lattice spacing d1 at a peak where the Bragg angle 2θ of the phthalocyanine crystal is in the range of 28.0° or more and 29.0° or less within an appropriate range, it is possible to increase the efficiency of carrier transport and improve the photoelectric conversion efficiency.

[0019] 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.

[0020] 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 gradually change, or a layer that can form a complex and intricate structure together with other layers.

[0021] FIG. 1 is a cross-sectional view showing a schematic example of the configuration of one embodiment of the photoelectric conversion element of the present invention. The photoelectric conversion element 1 of FIG. 1 has a second electrode 3, an electron transport layer 4, a photoelectric conversion layer 5, a charge transport layer 6, a second charge transport layer 7, and a first electrode 8 on a substrate 2. One of the first electrode 8 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 8 and the second electrode 3 with an external circuit. The photoelectric conversion element 1 preferably has a second charge transport layer 7. When the photoelectric conversion element 1 has the second charge transport layer 7, the charge transport layer (charge transport layer 6) containing phthalocyanine crystals becomes the first charge transport layer.

[0022] 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 8, the charge transport layer 6, and the second charge transport layer 7, and generates electrons or holes. That is, the photoelectric conversion layer 5 generates a current between the first electrode 8 and the second electrode 3. The electron transport layer 4 is a layer disposed between the photoelectric conversion layer 5 and the two electrodes 3 and 8, 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 be called a tandem structure. In addition, as shown in FIG. 2, a configuration may be used in which the first electrode 8, the second charge transport layer 7, the charge transport layer 6, the photoelectric conversion layer 5, the electron transport layer 4, and the second electrode 3 are provided on the substrate 2. Each component will be described below.

[0023] [Photoelectric conversion element] The photoelectric conversion element 1 of the present invention includes a first electrode 8, a second electrode 3, and a photoelectric conversion layer 5 containing a crystal of a perovskite structure disposed between the first electrode 8 and the second electrode 3, and a charge transport layer containing a phthalocyanine crystal is provided between the photoelectric conversion layer 5 and the first electrode 8. 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 5, a silicon solar cell, a CIGS solar cell, and the like.

[0024] Examples of the method for forming each layer including the photoelectric conversion layer and the charge transport layer of the photoelectric conversion element 1 of the present invention include a coating method and a deposition method. 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 a coating solution 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.

[0025] 〔substrate〕 The photoelectric conversion element 1 of the present invention may include a substrate 2, examples of which include a transparent glass substrate made of soda-lime glass or alkali-free glass, a ceramic substrate, and a transparent plastic substrate. In Fig. 1, when light is taken in from the first electrode 8 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.

[0026] 〔electrode〕 The materials of the first electrode 8 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 / 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 of them may be used in combination.

[0027] At least one of the first electrode 8 and the second electrode 3 on the light incident side is a transparent electrode, and the other may be a transparent electrode or may also serve as a reflective layer formed of a light-reflective material, or may be a transparent electrode provided with a reflective layer on the side opposite to the light incident side. As the photoelectric conversion element 1, it is preferable that the first electrode 8 is a positive electrode. When the first electrode 8 is on the light incident side, the second electrode 3 may be a transparent electrode and the substrate 2 may be a reflective layer. The transparent electrode may be a patterned electrode.

[0028] [Photoelectric Conversion Layer] The photoelectric conversion layer 5 has a crystal having a perovskite structure. The crystal having a perovskite structure used in the present invention is preferably represented by the following general formula [1]. ABX3[1] In the above general formula [1], A is a monovalent cation of an organic molecule or a metal atom, B is a divalent metal cation, and X is a monovalent halide anion. As A in the above general formula [1], for example, in the case of an organic molecule, C p N q H r (wherein p, q, and r are all positive integers) are preferable. Specific examples include methylammonium and formamidium.

[0029] 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.

[0030] When the constituent cation A is too large to fit within the crystal of the three-dimensional perovskite structure, it forms a crystal of a two-dimensional perovskite structure, a crystal of a 2.5-dimensional perovskite structure having both two-dimensional and three-dimensional properties, a two-layer crystal of a three-dimensional and two-dimensional perovskite structure, or a crystal of a mixed three-dimensional and two-dimensional perovskite structure, all of which function as the photoelectric conversion layer 5. A two-layer crystal of a three-dimensional and two-dimensional perovskite structure refers to a crystal in which crystals of a three-dimensional and two-dimensional perovskite structure are stacked as independent and separate layers, and a mixed three-dimensional and two-dimensional perovskite refers to a crystal in which regions or domains of both a two-dimensional or 2.5-dimensional layered and a three-dimensional perovskite structure crystal are mixed.

[0031] The crystals having a two-dimensional perovskite or 2.5-dimensional perovskite structure are preferably represented by the following general formulas [2] to [4]. 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, general formula [2] forms an RP (Ruddlesden-Popper) type perovskite structure, general formula [3] forms a DJ (Dion-Jacobson) type perovskite structure, and general formula [4] forms an ACI (Alternating cations in the interlayer) type perovskite structure.

[0032] 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, isobutylammonium, 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 ... Preferred are ammonium, 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, and 4-(aminomethyl)piperidinium.

[0033] In the above general formula [1] to the above general formula [4], B is a metal atom, and examples thereof include 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.

[0034] X in the above general formulas [1] to [4] is a halogen atom, etc., and examples thereof include 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 structure crystal is easily soluble in an organic solvent by containing a halogen in the structure, and can be applied to inexpensive printing methods, etc. Furthermore, iodine is more preferred because the energy band gap of the perovskite structure crystal is narrowed.

[0035] 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<h2 style=";text-align:left;direction:ltr">(FAPbI3)<h2 style=";text-align:left;direction:ltr"> 0.85 <h2 style=";text-align:left;direction:ltr"> (MAPbBr3)<h2 style=";text-align:left;direction:ltr"> 0.15 <h2 style=";text-align:left;direction:ltr"> CsPbI<h2 style=";text-align:left;direction:ltr"> 3、 <h2 style=";text-align:left;direction:ltr"> CsPbBr3, Cs<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> (MA)<h2 style=";text-align:left;direction:ltr"> 1-x <h2 style=";text-align:left;direction:ltr"> PbI3, Cs<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> (FA)<h2 style=";text-align:left;direction:ltr"> 1-x <h2 style=";text-align:left;direction:ltr"> PbI3, MA<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> (FA)<h2 style=";text-align:left;direction:ltr"> 1-x <h2 style=";text-align:left;direction:ltr"> PbI3, MA<h2 style=";text-align:left;direction:ltr"> 0.17 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.83 <h2 style=";text-align:left;direction:ltr"> Pb(I<h2 style=";text-align:left;direction:ltr"> 0.83 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.17 <h2 style=";text-align:left;direction:ltr"> 3.Cs<h2 style=";text-align:left;direction:ltr"> 0.15 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.85 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.55 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.45 <h2 style=";text-align:left;direction:ltr"> Cs<h2 style=";text-align:left;direction:ltr"> 0.05 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.88 <h2 style=";text-align:left;direction:ltr"> MA<h2 style=";text-align:left;direction:ltr"> 0.07 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.56 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.44 <h2 style=";text-align:left;direction:ltr"> Cs<h2 style=";text-align:left;direction:ltr"> 0.15 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.85 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.55 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.45 <h2 style=";text-align:left;direction:ltr"> (PEA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (PTA)2(MA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (PEA)2(MA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (ThMA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (3BBA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (ThMA)2(FA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (4FPEA)2(FA<h2 style=";text-align:left;direction:ltr"> 0.3 <h2 style=";text-align:left;direction:ltr"> MA<h2 style=";text-align:left;direction:ltr"> 0.7 <h2 style=";text-align:left;direction:ltr"> 4Pb5I)<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (PDMA)FA2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (3AMPY)(MA)3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (PDMA)MA5Pb6I<h2 style=";text-align:left;direction:ltr"> 19 <h2 style=";text-align:left;direction:ltr"> (PDMA)MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (TTDMA)MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (TTDMA)MA4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (BA<h2 style=";text-align:left;direction:ltr"> 0.9 <h2 style=";text-align:left;direction:ltr"> PEA<h2 style=";text-align:left;direction:ltr"> 0.1 <h2 style=";text-align:left;direction:ltr"> )2MA4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (BA<h2 style=";text-align:left;direction:ltr"> 0.9 <h2 style=";text-align:left;direction:ltr"> PEA<h2 style=";text-align:left;direction:ltr"> 0.1 <h2 style=";text-align:left;direction:ltr"> )2MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (4FPEA)2MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13, (4FPEA)2MA4Pb5I 16 , (BA)2MA2Pb3I 10 , (BA)2MA3Pb4I 13 , (TEA)2MA2Pb3I 10 , (BA)2MA4Pb5I 16 , (BA)2MA3Pb4I 13 , CsSnBr3, CsSnI3, FA 0.75 MA 0.25 Sn 0.95 Ge 0.05 I3, FAMASnGeI3, FASnBr3, FASnI3, MA2Sn3I8, MASnBr3, MASnGeI3, and MASnI3 are preferred. The A site, B site, and X site in the above general formula may be adjusted to be under- or over-adjusted depending on the purpose, and the combination of x1 to x5 may be changed depending on the purpose. The combination of x1 to x5 is, for example, as shown in Table 1. Particularly preferred ranges are 0.03≦x1≦0.10, 0.80≦x2≦0.96, 0.95≦x3≦1.05, 0.80≦x4≦0.96, and 2.95≦x5≦3.05. MACl may be included as a material for forming perovskite crystals.

[0036] [Table 1]

[0037] 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.

[0038] 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 by having such a structure, the orientation of the octahedron in the crystal lattice can be easily changed, thereby increasing the mobility of electrons in the crystal with the perovskite structure and improving the photoelectric conversion efficiency of the photoelectric conversion element 1.

[0039] 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 1 is improved.

[0040] The thickness of the photoelectric conversion layer 5 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 charges can be transported to each electrode. A more preferred lower limit is 50 nm or more, a more preferred upper limit is 1200 nm, a still more preferred lower limit is 100 nm, and a still more preferred upper limit is 1000 nm.

[0041] [Charge transport layer] The charge transport layer 6 of the present invention has phthalocyanine crystals. In the phthalocyanine material of the present invention, the term "crystals" means that the half-width of a peak in the Bragg angle 2θ range of 28.0° to 29.0° in the X-ray diffraction measurement described below is 1.0° or less.

[0042] In the photoelectric conversion element 1 of the present invention, the phthalocyanine crystal is preferably a gallium phthalocyanine crystal, more preferably a hydroxygallium phthalocyanine crystal. The phthalocyanine crystal used in the present invention may have a central element, such as Ga, Cu, Ti, Zn, Si, V, Pb, Pt, Co, Sn, Mg, Fe, Al, Mn, etc., and among them, a gallium phthalocyanine compound whose central element is Ga is preferable. Among gallium phthalocyanines, hydroxygallium phthalocyanine is more preferable. The phthalocyanine crystal may be a derivative having a phthalocyanine skeleton. Gallium phthalocyanine has good electronic interaction with a resin having a functional group of a Lewis base, and it is presumed that hydroxygallium phthalocyanine has a stronger interaction with a Lewis base due to the presence of a hydroxy group, thereby improving the photoelectric conversion efficiency.

[0043] Specific examples of the phthalocyanine crystal of the present invention are given below. The phthalocyanine crystal of the present invention is, for example, 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.

[0044] The phthalocyanine crystal of the present invention is, for example, naphthalocyanine, magnesium naphthalocyanine, copper naphthalocyanine, magnesium naphthalocyanine, cobalt naphthalocyanine, vanadyl naphthalocyanine, tin naphthalocyanine, and dichlorotin naphthalocyanine. In the present invention, the chemical structure of the phthalocyanine crystal or the like can be confirmed, for example, by nuclear magnetic resonance (NMR) spectroscopy.

[0045] In the photoelectric conversion element 1 of the present invention, the charge transport layer 6 preferably contains a resin. From the viewpoint of film-forming property and charge transport ability, when the content of the phthalocyanine crystal in the charge transport layer 6 is taken as 100 parts by mass, the content of the resin in the charge transport layer 6 is preferably 3 parts by mass or more and 30 parts by mass or less, and more preferably 5 parts by mass or more and 20 parts by mass or less. When the film-forming property is improved by containing a resin, the number of leak points caused by the roughness of the photoelectric conversion layer 5 is reduced, and the photoelectric conversion efficiency is improved. The content of the resin can be quantified using a nuclear magnetic resonance (NMR) device or a gas chromatography device.

[0046] The molecular weight of the resin is preferably 10,000 or more. Resins that are 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, and polyvinyl chloride resins.

[0047] Furthermore, the resin preferably has a glass transition temperature of 95° C. or less. Within this range, the resin can easily come into intimate contact with the charge transport material (charge transport particles), forming a more effective charge distribution. The glass transition temperature can be determined by a differential scanning calorimeter (DSC).

[0048] 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.

[0049] In the photoelectric conversion element 1 of the present invention, in the X-ray diffraction spectrum using CuKα radiation for the charge transport layer 6 having the phthalocyanine crystal, a peak exists in the range of the Bragg angle 2θ of 28.0° or more and 29.0° or less, and the lattice spacing d1 [nm] calculated from the value of 2θ of the peak is 0.3100≦d1≦0.3160 In the photoelectric conversion element 1 of the present invention, the lattice spacing d1 [nm] calculated from the 2θ value of the peak is 0.3120≦d1≦0.3160 It is preferable that 0.3145≦d1≦0.3155 It is more preferable that the following conditions are satisfied.

[0050] In the present invention, in an X-ray diffraction spectrum using CuKα radiation, the lattice spacing d1 [nm] calculated from the value of 2θ of a peak in which the Bragg angle 2θ is in the range of 28.0° to 29.0° can be calculated using θ1 [rad], which is the θ obtained from a peak in the range of 28.0° to 29.0°, and the X-ray wavelength λ [nm] (λ = 0.15418 in the case of an X-ray diffraction spectrum using CuKα radiation), using the Bragg equation shown below (1). d1=λ / (2sinθ1) (1)

[0051] Here, when a peak derived from phthalocyanine crystals exists between 28.0° and 29.0°, the angle θ at the point with the highest peak intensity is defined as θ1. Here, the meanings of "particle", "crystallite" and "crystallite size d2 (nm)" of the phthalocyanine crystal in the present invention will be explained. In the present invention, a "particle" of a phthalocyanine crystal is a primary particle of a phthalocyanine crystal formed by an aggregation of phthalocyanine molecules. On the other hand, a "crystallite" of a phthalocyanine crystal is the smallest unit part that can be regarded as a single crystal of phthalocyanine in the above crystal particle, and the crystallite size d2 means the size of the crystallite.

[0052] In the present invention, the crystallite size d2 [nm] of the phthalocyanine crystal was calculated from a peak present in the Bragg angle 2θ range of 28.0° to 29.0° in the X-ray diffraction spectrum using CuKα radiation. The crystallite size d2 can be expressed by the following formula (2) using the Scherrer formula: Scherrer constant K [-], X-ray wavelength λ [nm], half-width β [rad], and θ1 [rad]. d2=K·λ / (β·cosθ1) ···(2)

[0053] The larger the crystallite size d2, the fewer the number of crystallite interfaces that cause the transport of carriers injected from the photoelectric conversion layer 5 to be hindered, and therefore the increase in resistance and the voltage drop due to the retention of carriers are suppressed, and the photoelectric conversion efficiency is improved. In the photoelectric conversion element 1 of the present invention, the crystallite size d2 calculated from the half-width of the peak is: d2≧ 19.5 It is preferable that d2≧ 20.0 It is more preferable that the following conditions are satisfied.

[0054] On the other hand, if the crystallites are too large, the crystal size varies and the surface properties of the charge transport layer 6 deteriorate, so that the shunt resistance decreases and the photoelectric conversion efficiency is adversely affected. d2≦ 21.1 It is preferable that the following is satisfied. The number-average particle size of the phthalocyanine crystals is preferably 50 nm or more and 150 nm or less.

[0055] Dispersion methods for turning phthalocyanine crystals into particles include methods using a paint shaker, sand mill, ball mill, and liquid collision type high-speed disperser. If the dispersion method is changed, the load on the phthalocyanine material will be different, so the values ​​of d1 and d2 will be significantly different.

[0056] Among them, the sand mill breaks down crystals into particles by the shearing force of the rotating disk inside the mill and the grinding media such as glass beads. The lattice spacing d1, crystallite size d2, and number-average particle size change due to the change in crystallinity 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 a degree that does not cause overdispersion (aggregation of particles or formation of fragments, etc.), both d1 and d2 tend to decrease. In addition, by changing the temperature during dispersion, it is possible to change d2 while keeping the change in d1 small. It is presumed that the amount of change in d1 and d2 changes depending on the balance between the change in temperature that promotes the growth of crystallites and the change in dispersion strength due to temperature change. Furthermore, d1 and d2 vary greatly depending on the type of central element of the phthalocyanine crystal, the crystal form, or the solvent used during dispersion.

[0057] The phthalocyanine crystal may contain a part of the solvent used for dispersion in the crystal. The solvent contained in the crystal is preferably any one selected from the group consisting of N-methylformamide, N-ethylformamide, N-propylformamide, and dimethylsulfoxide, and among these, N-methylformamide is more preferable. That is, in the photoelectric conversion element 1 of the present invention, the phthalocyanine crystal preferably contains N-methylformamide. Since these materials have a large pKa and a large dipole moment, the charge bias inside the material becomes large, and the carrier mobility increases, thereby improving the photoelectric conversion efficiency. The method of introducing the organic compound into the crystal is not particularly limited, but for example, there is a method of making the organic compound coexist in the crystallization process. As for the amount of the organic compound in the crystal, there is a method of changing various conditions such as the processing time and processing strength in the crystallization process.

[0058] If the photoelectric conversion layer 5 has a large roughness, the photoelectric conversion layer 5 and the first electrode 8 come into direct contact with each other, which is thought to cause a decrease in the photoelectric conversion efficiency due to a decrease in the shunt resistance and a decrease in durability during long-term storage. Therefore, by increasing the thickness of the charge transport layer 6 to a certain level or more, it is possible to suppress the contact between the photoelectric conversion layer 5 and the first electrode 8 and improve the photoelectric conversion efficiency and durability. On the other hand, if the thickness of the charge transport layer 6 is too thick, the efficiency of carrier transport decreases, so it is preferable that the thickness of the charge transport layer 6 is not too thick. In the photoelectric conversion element 1 of the present invention, the average thickness of the charge transport layer 6 is preferably 30 nm or more and 400 nm or less, more preferably 50 nm or more and 180 nm or less.

[0059] The measurement of the X-ray diffraction spectrum of the charge transport layer 6 and confirmation of the contained phthalocyanine crystals can be carried out, for example, by removing the layers above the charge transport layer 6 of the photoelectric conversion element 1 with an organic solvent such as chloroform, and then exposing the surface of the charge transport layer 6. In the examples of the present invention, unless otherwise specified, the measurement of the X-ray diffraction spectrum and confirmation of the contained phthalocyanine crystals were carried out in a state where the charge transport layer 6 was exposed by the above-mentioned method.

[0060] [X-ray diffraction measurement] In the present invention, the X-ray diffraction spectrum of the charge transport layer 6 exposed under the following conditions was measured. The obtained X-ray diffraction spectrum of the charge transport layer 6 was smoothed, and the peak position of the peak present in the range of 28.0° to 29.0° was taken as θ1 [rad], and the half-width of the peak was taken as half-width β [rad]. In the analysis, the Scherrer constant K differs depending on the shape of the crystal and how the half-width is taken, but in the present invention, the calculation was performed with K=0.89. 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: 0.5° / min Sampling interval: 0.01° Start angle 2θ: 5.0° Stop angle 2θ: 35.0° 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

[0061] [Analysis of compound amounts] In the embodiment of the present invention, the surface of the charge transport layer 6 of the photoelectric conversion element 1 was wiped with a cotton swab or the like soaked in a solvent, dissolved in heavy water sulfuric acid, and subjected to 1H-NMR measurement (apparatus: AVANCE3-500, manufactured by BRUKER). The peeled off components were subjected to mass and structure analyses such as GPC, MALDI-TOF-MS, IR, and gas chromatography, as well as elemental analyses such as EDX and XPS, and the types of phthalocyanine crystals, the presence of organic compounds contained in the crystals such as N-methylformamide, and compounds such as resins were confirmed in conjunction with the results of the X-ray diffraction measurement.

[0062] [Measurement of average film thickness] In the present invention, the average film thickness of the charge transport layer 6 was confirmed by cutting the photoelectric conversion element 1, fixing it on an inclined sample stage, and then observing the cross section using a scanning electron microscope (hereinafter also referred to as "SEM") (apparatus: Carl Zeiss, SmartSEM). In the observation, the charge transport layer 6 was distinguished from other layers based on the difference in contrast of the observed image and composition analysis using the SEM-EDX function, and the average film thickness of the charge transport layer 6 portion was measured by image processing of an image taken at a magnification of 50,000 times. This was taken at five random locations, and the average of the five average values ​​was taken as the average film thickness of the charge transport layer 6.

[0063] [Second Charge Transport Layer] From the viewpoint of film compatibility of the charge transport layer, the photoelectric conversion element 1 of the present invention preferably has a second charge transport layer 7 between the charge transport layer 6 and the first electrode 8. In that case, the charge transport layer containing phthalocyanine crystals (charge transport layer 6) becomes the first charge transport layer. The material of the second charge transport layer 7 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 and PTAA are more preferable.

[0064] 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.

[0065] [Electron transport layer] In the photoelectric conversion element 1 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-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.

[0066] 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.

[0067] <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 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 may also have the photoelectric conversion element of the present invention and an inverter. The inverter may be a converter that converts direct current to alternating current. The photoelectric conversion device may have a storage unit connected to the photoelectric conversion element. The storage unit is not limited as long as it can store electricity. For example, a secondary battery using lithium ions, an all-solid-state battery, and an electric double layer capacitor can be mentioned. In order to impart a function such as maintaining or increasing the amount of incident light, a surface layer that is resistant to water and dirt, or a function of collecting or guiding light may be added.

[0068] [Mobile object] The moving body of the present invention has the above-mentioned photoelectric conversion element. FIG. 3 is a perspective view showing an embodiment of a moving body having a photoelectric conversion element of the present invention. The moving body 30 has a photoelectric conversion element 31 of the present invention and a vehicle 32 having 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.

[0069] 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.

[0070] [Building materials] The building material of the present invention has the above-mentioned photoelectric conversion element. Fig. 4 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.

[0071] 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.

[0072] 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. The exteriors 44a and 44b may be made of the same material or different materials. Paint or a transparent substrate may be used as the exterior. A material with low light absorption and high heat insulation is preferable.

[0073] In addition to the above application examples, the following application examples can be mentioned. Examples of portable devices include calculators, sensors, and small solar panels. Examples of wearable devices include glasses-type terminals, wristwatch-type terminals, and portable medical equipment. Examples of sheet structures supported by multiple frames include tents, vinyl greenhouses, and truck beds. Examples of structures that are used in a fixed position include 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.

[0074] [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, forming a photoelectric conversion layer containing crystals with a perovskite structure between the first electrode and the second electrode, and forming a charge transport layer between the photoelectric conversion layer and the first electrode. Each step of the manufacturing method will be described below.

[0075] (Step of forming a first electrode and step of forming a second electrode) The method for manufacturing the 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.

[0076] (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.

[0077] (Step of forming photoelectric conversion layer) The method for manufacturing the 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 may include a step of applying a liquid containing the material of the photoelectric conversion layer described above. Examples of the application method include spin coating, blade coating, slit die coating, screen printing, bar coater, casting, printing transfer, immersion and pulling, inkjet, spraying, and vacuum deposition. Among these, a method is appropriately selected according to the characteristics of the photoelectric conversion layer to be prepared, such as thickness control and orientation control.

[0078] 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.

[0079] (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, such as spin coating, blade coating, slit die coating, screen printing, bar coater, casting, print transfer, immersion and pulling, inkjet, spraying, and vacuum deposition.

[0080] Examples of the process for forming the charge transport layer include the following. A method of disposing charge transport particles on the surface of the photoelectric conversion layer, applying a resin solution in which a resin is dissolved, and then drying the resulting solution. Alternatively, a method of disposing charge transport particles on the surface of the photoelectric conversion layer, applying a resin solution in which a resin is dissolved, and then drying the resin solution. Alternatively, a method of dispersing charge transport particles in a resin solution in which a resin is dissolved, and then applying the solution to the surface of the photoelectric conversion layer and drying the resulting solution. EXAMPLES

[0081] 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.

[0082] (Preparation process of phthalocyanine crystal 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% by mass.

[0083] 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.

[0084] Process (3) Five parts of the hydroxygallium phthalocyanine particles were dispersed in 100 parts of N-methylformamide solvent and 100 parts of glass beads in a sand mill (TSG-1 / 4G-4U, manufactured by Igarashi Machinery Manufacturing Co., Ltd. (now Imex), disk diameter 70 mm, number of disks 5) by rotating the disks at 300 rpm and dispersing at 25°C for 30 hours, followed by filtration and drying to obtain phthalocyanine crystals 1.

[0085] (Preparation process of phthalocyanine crystals 2 to 16) Phthalocyanine crystals 2 to 16 were prepared in the same manner as in the preparation of phthalocyanine crystal 1, except that the solvent used in step (3), the temperature during the dispersion treatment, and the dispersion time were changed as shown in Table 2. Phthalocyanine crystal 14 was prepared by performing dispersion, filtration, drying in step (3), and then centrifugal separation to remove coarse particles.

[0086] [Table 2]

[0087] (Preparation of resin solution 1) 1.0 g of polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd., glass transition temperature 71° C.) was dissolved in 19 g of 2-propanol with stirring for 24 hours to obtain resin solution 1.

[0088] (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.

[0089] (Preparation of resin solution 3) 1.0 g of polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich, glass transition temperature 70° C.) was dissolved in 19 g of 2-propanol with stirring for 24 hours to obtain resin solution 3.

[0090] (Preparation of resin solution 4) Resin solution 4 was obtained by dissolving 1.0 g of polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich, glass transition temperature 100° C.) in 19 g of 2-propanol with stirring for 24 hours.

[0091] Example 1 [Formation of Electron Transport Layer] A glass substrate with ITO was cleaned, and tin(II) oxide prepared to a concentration of 3% by mass was spin-coated onto it. 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.

[0092] [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 500 μL of N,N-dimethylformamide and 200 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 Cs0.05 (FA 0.83 MA 0.17 ) 0.96 Pb(I 0.95 Br 0.05 A photoelectric conversion layer having a thickness of 500 nm was formed from the above-mentioned film 3.

[0093] [Formation of Charge Transport Layer] 0.1 g of the phthalocyanine crystal 1 and 0.01 g of the calixarene compound (JP Patent Publication 2003-207913) were enclosed in 10.6 g of 2-propanol and 11 g of zirconia beads, and dispersed in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) for 6 hours, and then 0.2 g of resin solution 1 was added, and dispersion was again carried out in the paint shaker for 6 hours to prepare a coating liquid for a charge transport layer. The obtained coating liquid for the charge transport layer was spin-coated on the photoelectric conversion layer to form a charge transport layer having a thickness of 100 nm.

[0094] [Formation of the 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 36 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 0.5 g of acetonitrile was mixed to prepare a charge transport coating solution 1. This charge transport coating solution 1 was applied on the charge transport layer by spin coating to form a second charge transport layer having a thickness of 100 nm.

[0095] [Formation of the first electrode] A layer having a thickness of 80 nm and an area of ​​0.09 cm2 was deposited on the second charge transport layer. 2 A gold electrode was formed by vacuum deposition to obtain a photoelectric conversion element. The photoelectric conversion element thus obtained was subjected to measurements of the amounts of the above compounds, N-methylformamide, average film thickness, and X-ray diffraction to determine the composition of the phthalocyanine crystal, the presence or absence of NMF (N-methylformamide) in the phthalocyanine crystal, the film thickness of the charge transport layer, and d1 and d2. The results are shown in Tables 3 and 4.

[0096] (Preparation of Examples 2 and 3) Examples 2 and 3 were produced in the same manner as in Example 1, except that the type of phthalocyanine crystal used and the amount of phthalocyanine crystal enclosed were changed as shown in Table 3.

[0097] (Preparation of Examples 4 to 28) Examples 4 to 28 are prepared in the same manner as Example 1, except that the type of phthalocyanine crystals, the amount of phthalocyanine crystals enclosed, and the type of resin solution used are changed as shown in Table 3. However, in Examples 14 to 16, the charge transport layer coating liquid is prepared without adding the resin solution and dispersing with a paint shaker thereafter in forming the charge transport layer. Also, Example 26 is prepared without forming a second charge transport layer.

[0098] [Table 3]

[0099] (Preparation of Comparative Example 1) Comparative Example 1 was prepared in the same manner as in Example 1, except that in the preparation of Example 1, the charge transport layer was changed to the particle layer prepared in Example 1 described in JP-A-2022-168820.

[0100] (Preparation of Comparative Example 2) Comparative Example 1 was prepared in the same manner as in Example 1, except that in the preparation of Example 1, the charge transport layer was changed to the particle layer prepared in Example 9 described in JP-A-2022-168820.

[0101] (Preparation of Comparative Example 3) Comparative Example 3 is prepared in the same manner as in Example 18, except that chlorogallium phthalocyanine 1 is changed to chlorogallium phthalocyanine 2, which has strong peaks at 9.0±0.2°, 17.6±0.2°, 27.4±0.2°, and 28.8±0.2° in the X-ray diffraction spectrum.

[0102] (Preparation of Comparative Example 4) Comparative Example 4 is prepared in the same manner as in Example 20, except that copper phthalocyanine 1 is changed to copper phthalocyanine 2, which has strong peaks at 7.0±0.2°, 9.2±0.2°, 12.5±0.2°, 16.8±0.2°, 18.6±0.2°, 21.3±0.2°, 23.8±0.2°, 26.2±0.2°, 28.0±0.2°, and 30.5±0.2° in the X-ray diffraction spectrum.

[0103] (Preparation of Comparative Examples 5 and 6) Comparative Examples 5 and 6 were prepared in the same manner as in Example 1, except that the phthalocyanine crystal 1 was changed as shown in Table 3.

[0104] 〔evaluation〕 [Photoelectric conversion 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 a certain amount of light using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) and measuring the generated current and voltage. The series resistance was calculated by approximating the inverse of the slope of the obtained current-voltage curve near Voc (open circuit voltage), and the shunt resistance was calculated by approximating the inverse of the slope of the obtained current-voltage curve near Jsc (short circuit current density). The results are shown in Table 4.

[0105] [X-ray diffraction measurement] The X-ray diffraction measurement was performed by the above method on the sample obtained in Example 1. In the measurement, a sample in which the layers above the charge transport layer were peeled off and a sample in which the layers up to the charge transport layer were peeled off were prepared, and the difference between the two data was taken to obtain an X-ray diffraction spectrum of only the charge transport layer, and the values ​​of 2θ and half width were calculated.

[0106] Next, in the preparation of Example 1, a sample in which the photoelectric conversion layer was formed and a sample in which the charge transport layer was formed were prepared and subjected to X-ray diffraction measurement. The values ​​of 2θ and full width at half maximum were the same as the X-ray diffraction results of the sample obtained by peeling off the upper layer. The evaluation of the samples prepared in Examples 2 to 28 and Comparative Examples 1 to 6 was performed using the sample in which the photoelectric conversion layer was formed and the sample in which the charge transport layer was formed. The results are shown in Table 4.

[0107] [Analysis of compound amount, measurement of average film thickness] The types of compounds in the phthalocyanine crystals, the presence or absence of NMF in the phthalocyanine crystals, the average film thickness of the charge transport layer, and the presence of resin in the charge transport layer were confirmed by the above-mentioned methods. The results are shown in Table 3.

[0108] [Table 4]

[0109] 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, the photoelectric conversion layer being disposed between the first electrode and the second electrode, the photoelectric conversion element has a charge transport layer containing a phthalocyanine crystal between the photoelectric conversion layer and the first electrode, In an X-ray diffraction spectrum of the phthalocyanine crystal using CuKα radiation, a peak exists within a range of a Bragg angle 2θ of 28.0° or more and 29.0° or less, The lattice spacing d1 [nm] calculated from the 2θ value of the peak is 0.3100≦d1≦0.3160 A photoelectric conversion element satisfying the above requirements. (Configuration 2) The crystallite size d2 [nm] calculated from the half width of the peak is d2≧ 19.5 The photoelectric conversion element according to configuration 1, (Configuration 3) The crystallite size d2 [nm] calculated from the half width of the peak is d2≧ 20.0 The photoelectric conversion element according to configuration 1, (Configuration 4) The crystallite size d2 [nm] calculated from the half width of the peak is d2≦ 21.1 4. The photoelectric conversion element according to any one of configurations 1 to 3, which satisfies the above. (Configuration 5) The lattice spacing d1 [nm] is 0.3145≦d1≦0.3155 5. The photoelectric conversion element according to any one of configurations 1 to 4, which satisfies the above. (Configuration 6) 6. The photoelectric conversion element according to any one of configurations 1 to 5, wherein the charge transport layer contains a resin. (Configuration 7) The photoelectric conversion element according to any one of configurations 1 to 6, further comprising a second charge transport layer between the first electrode and the charge transport layer. (Configuration 8) The photoelectric conversion element according to any one of configurations 1 to 7, wherein the phthalocyanine crystal is a gallium phthalocyanine crystal. (Configuration 9) The photoelectric conversion element according to any one of configurations 1 to 8, wherein the phthalocyanine crystal is a hydroxygallium phthalocyanine crystal. (Configuration 10) 10. The photoelectric conversion element according to any one of configurations 1 to 9, wherein the phthalocyanine crystal contains N-methylformamide. (Configuration 11) 11. The photoelectric conversion element according to any one of configurations 1 to 10, wherein the charge transport layer has an average thickness of 50 nm or more and 180 nm or less. (Configuration 12) A photoelectric conversion device comprising the photoelectric conversion element according to any one of configurations 1 to 11. (Configuration 13) A moving object having the photoelectric conversion element according to any one of configurations 1 to 11. (Configuration 14) A building material comprising the photoelectric conversion element according to any one of configurations 1 to 11. [Explanation of symbols]

[0110] 1 Photoelectric conversion element 2. Board 3 Second electrode 4 Electron transport layer 5 Photoelectric conversion layer 6 Charge transport layer 7 Second Charge Transport Layer 8 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, the photoelectric conversion layer being disposed between the first electrode and the second electrode, the photoelectric conversion element has a charge transport layer containing a phthalocyanine crystal between the photoelectric conversion layer and the first electrode, In an X-ray diffraction spectrum of the phthalocyanine crystal using CuKα radiation, a peak exists within a range of a Bragg angle 2θ of 28.0° or more and 29.0° or less, The lattice spacing d calculated from the 2θ value of the peak １ [nm] is 0.3100 ≦ d １ ≦ 0.3160 A photoelectric conversion element satisfying the above requirements.

2. The crystallite size d calculated from the half-width of the peak ２ [nm] is d ２ ≧ 19.5 The photoelectric conversion element according to claim 1 , which satisfies the above.

3. The crystallite size d calculated from the half-width of the peak ２ [nm] is d ２ ≧ 20.0 The photoelectric conversion element according to claim 1 , which satisfies the above.

4. The crystallite size d calculated from the half-width of the peak ２ [nm] is d ２ ≦ 21.1 The photoelectric conversion element according to claim 1 , which satisfies the above.

5. The lattice spacing d １ [nm] is 0.3145 ≦ d １ ≦ 0.3155 The photoelectric conversion element according to claim 1 , which satisfies the above.

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

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

8. 2. The photoelectric conversion element according to claim 1, wherein the phthalocyanine crystal is a gallium phthalocyanine crystal.

9. 2. The photoelectric conversion element according to claim 1, wherein the phthalocyanine crystal is a hydroxygallium phthalocyanine crystal.

10. 2. The photoelectric conversion element according to claim 1, wherein the phthalocyanine crystal contains N-methylformamide.

11. 2. The photoelectric conversion element according to claim 1, wherein the charge transport layer has an average thickness of 50 nm or more and 180 nm or less.

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

13. A moving object comprising the photoelectric conversion element according to any one of claims 1 to 11.

14. A building material comprising the photoelectric conversion element according to any one of claims 1 to 11.

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