Photoelectric conversion element, photoelectric conversion device, mobile body, building material, and composition

Abstract

The present disclosure addresses the problem of providing a photoelectric conversion element having superior photoelectric conversion efficiency. In order to solve the problem, the present disclosure provides a photoelectric conversion element comprising a first electrode (7), a second electrode (3), and a photoelectric conversion layer (5) that is disposed between the first electrode (7) and the second electrode (3) and contains crystals having a perovskite structure. The photoelectric conversion element is characterized by comprising a charge transport layer (6) between the photoelectric conversion layer (5) and the first electrode (7), wherein the charge transport layer (6) includes a cyclic conjugated compound and a calixarene compound, the cyclic conjugated compound being formed by conjugated coupling of a plurality of pyrrole rings, and the charge transport layer (6) includes a compound that improves current density. Alternatively, the photoelectric conversion element is characterized by comprising a surface modification layer between the charge transport layer (6) and the first electrode (7).

Description

Photoelectric conversion elements, photoelectric conversion devices, mobile bodies, building materials, and compositions

[0001] This disclosure relates to photoelectric conversion elements, photoelectric conversion devices, mobile devices, building materials, and compositions.

[0002] In order to address the depletion of fossil fuels and the environmental problems caused by their use, research into renewable and clean alternative energy sources such as solar, wind, and hydroelectric power is actively being conducted. Among these, there is growing interest in solar cells, which directly convert sunlight into electrical energy. Here, a solar cell refers to a battery that absorbs light energy from sunlight and generates current and voltage using the photovoltaic effect, which generates electrons and holes.

[0003] Currently, n-p diode type silicon (Si) single-crystal based solar cells with a light energy conversion efficiency exceeding 20% ​​are widely known and actually used in photovoltaic power generation. However, these have the problem of high cost per unit of power due to the need for high-temperature processing and the high price of the material itself. Furthermore, there are supply issues from the perspective 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 using a so-called roll-to-roll method on a sheet-like substrate, which is expected to reduce costs.

[0005] However, further improvements in power generation efficiency and durability are desired for the practical application of organic solar cells. In particular, perovskite solar cells, which have a perovskite structure crystal as the photoelectric conversion layer, are being developed toward the practical application of solar cells because of their excellent photoelectric conversion properties.

[0006] For example, Patent Document 1 describes a configuration in which the hole transport layer contains an organic semiconductor component and a structure in which an electron-withdrawing group is bonded to a heteroatom. Patent Document 2 also describes a configuration having a charge transport layer containing a phthalocyanine compound and an aromatic ring compound having a hydroxyl group.

[0007] Japanese Patent Publication No. 2018-82140 Japanese Patent Publication No. 2024-60579

[0008] According to the inventors' studies, the photoelectric conversion elements described in Patent Documents 1 and 2 still have room for improvement in achieving even higher conversion efficiency. Therefore, the object of this disclosure is to provide a photoelectric conversion element with superior photoelectric conversion efficiency. Another object of this disclosure is to provide a coating composition that can improve photoelectric conversion efficiency.

[0009] The above objectives are achieved by the present disclosure below. Specifically, the present disclosure is a photoelectric element having a first electrode, a second electrode, and a photoelectric conversion layer comprising a perovskite crystal disposed between the first electrode and the second electrode, wherein the photoelectric conversion layer has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer comprising a cyclic conjugated compound formed by the conjugation of a plurality of pyrrole rings and a calixarene compound, the charge transport layer comprising a compound that improves current density, or the photoelectric element having a surface modification layer between the charge transport layer and the first electrode. The present disclosure is also a photoelectric conversion device having the above photoelectric element. The present disclosure is also a composition comprising a pigment which is a cyclic conjugated compound formed by the conjugation of a plurality of pyrrole rings, a calixarene compound, a solvent, a compound that improves current density, or a compound that forms a surface modification layer.

[0010] According to this disclosure, it is possible to provide a photoelectric conversion element with excellent photoelectric conversion efficiency, a photoelectric conversion device, and a coating composition that can improve photoelectric conversion efficiency.

[0011] This is a schematic cross-sectional view in the thickness direction of one embodiment of the photoelectric conversion element of the present disclosure. This is a schematic perspective view showing one embodiment of a mobile body equipped with the photoelectric conversion element of the present disclosure. This is a schematic perspective view showing one embodiment of a building material equipped with the photoelectric conversion element of the present disclosure.

[0012] <Embodiments> The embodiments relate to a photoelectric conversion element and a composition. The photoelectric conversion element of the present disclosure is a photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer containing a perovskite crystal disposed between the first electrode and the second electrode, wherein the photoelectric conversion layer has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer contains a cyclic conjugated compound formed by the conjugation bonding of a plurality of pyrrole rings and a calixarene compound, the charge transport layer contains a compound that improves current density, or the photoelectric conversion element has a surface modification layer between the charge transport layer and the first electrode. Furthermore, the composition of the present disclosure contains a pigment which is a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated, a calixarene compound, a solvent, a compound that improves current density, or a compound that forms a surface modification layer.

[0013] As a result of their investigation, the inventors have found that having the above-mentioned charge transport layer results in a photoelectric conversion element with excellent photoelectric conversion efficiency. Although the details of why such high efficiency is obtained in this disclosure are not clear, it is thought to be as follows.

[0014] The photoelectric conversion element of the present disclosure comprises a charge transport layer comprising a cyclic conjugated compound formed by the conjugation bonding of a plurality of pyrrole rings and a calixarene compound, wherein the charge transport layer comprises a compound that improves the current density, or the photoelectric conversion element has a surface modification layer between the charge transport layer and the first electrode.

[0015] Specifically, for example, if the charge transport layer contains a cyclic conjugated compound formed by the conjugation of multiple pyrrole rings having charge transport ability, a calixarene compound, and a compound that improves current density, then it is possible to efficiently extract charge from the photoelectric conversion layer and efficiently transfer the charge to a layer located on the opposite side of the photoelectric conversion layer without it accumulating in the charge transport layer. By including a compound that improves current density in the charge transport layer, the charge transport ability of the cyclic conjugated compound formed by the conjugation of multiple pyrrole rings is enhanced, and the flow of charge can be increased.

[0016] Furthermore, the calixarene compound can facilitate the transfer of increased charge between cyclic conjugated compounds, which are formed by the conjugation of multiple pyrrole rings. Moreover, for efficient charge transfer to the layer located opposite the photoelectric conversion layer, the interfacial energy levels and adhesion are important, and with the configuration of this disclosure, it is possible to improve the selection of energy levels and adhesion without reducing the charge transport capacity in the charge transport layer.

[0017] This disclosure prefers that the cyclic conjugated compound be a pigment. The charge transport ability can be further improved if the cyclic conjugated compound is a pigment. Furthermore, the average particle size of the pigment is preferably 10 nm to 400 nm, and more preferably 50 nm to 250 nm. Within this particle size range, the charge transport ability can be further improved.

[0018] This disclosure indicates that, from the viewpoint of charge transport ability, the cyclic conjugated compound is more preferably a phthalocyanine compound, and even more preferably a compound having the structure shown in the following formula (Pc-1).

[0019] This disclosure provides that in formula (Pc-1), M is H ２ Preferably, the metal atom has a ligand or does not have a ligand, and more preferably, M is gallium, aluminum, titanium, iron, or silicon, which has a ligand. The present disclosure prefers that the cyclic conjugated compound is a hydroxygallium compound or a chlorogallium phthalocyanine compound.

[0020] In particular, M in the above formula (Pc-1) is H ２ When this is the case, the above equation (Pc-1) is given by the following equation (Pc-2). To change the energy levels of the charge transport layer and improve charge extraction, substituents may be introduced into the cyclic conjugated compound.

[0021] This disclosure prefers that the calixarene compound be represented by the following formula (A) from the viewpoint of charge extraction and transfer between cyclic conjugated compounds formed by the conjugation of multiple pyrrole rings, and at the interface. (In the above formula (A), R １~R ５ is, independently within each repeating unit and independently for each of n repeating units, R １ represents a hydrogen atom or an alkyl group, and R ２ represents a substituted or unsubstituted alkylene group, and R ３ ~R ５ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted -Y-Ar group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group, and R ３ ~R ５ Among them, at least one is a -Y-Ar group having a substituent. The -Y- represents -CH=N-, -CH=CH-, or -N=N-, and the Ar is a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group. n is an integer of 3 or more and 20 or less. )

[0022] The above R １ and R ３ ~R ５ Examples of the alkyl group mentioned by R ３ ~R ５ include a methyl group, an ethyl group, a propyl group, a butyl group, and the like. The aromatic hydrocarbons mentioned by R

[0023] Also, the above R ３ ~R ５ Examples of the heterocyclic ring mentioned by R

[0024] Also, R ３ ~R ５Examples of substituents that alkyl groups, phenylazo groups, aromatic hydrocarbon groups, and heterocycles may have include alkyl groups such as methyl, ethyl, propyl, and butyl groups; alkoxy groups such as methoxy and ethoxy groups; dialkylamino groups such as dimethylamino and diethylamino groups; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; halogen atoms such as fluorine, chlorine, and bromine atoms; hydroxyl groups, nitro groups, cyano groups, and halomethyl groups.

[0025] This disclosure prefers that n in formula (A) be 4 or 8 from the viewpoint of charge extraction and transfer. Furthermore, this disclosure also prefers that R in formula (A) be 4 or 8. ４ However, it is preferable from the viewpoint of charge extraction and transfer that each of the n repeating units independently has a nitrophenylazo group or a dinitrophenylazo group. Furthermore, in this disclosure, it is preferable from the viewpoint of charge extraction and transfer that the molecular weight of the calixarene compound of formula (A) is 10,000 or less.

[0026] Furthermore, in this disclosure, R １ However, it is preferable that each of the n repeating units is independently hydrogen or a methyl group, an ethyl group, or a propyl group. Also, R ２ However, it is preferable that each of the n repeating units independently consists of a methylene group, an ethylene group, or a propylene group. ３ , R ５ However, it is preferable that it be a hydrogen group.

[0027] This disclosure prefers that the calixarene compound of formula (A) be a mixture of the compound shown in formula (C-1), the compound shown in formula (C-2), the compound shown in formula (C-3), and the compound shown in formula (C-4) below, from the viewpoint of charge extraction and transfer.

[0028] This disclosure prefers that the compound that improves the current density is a dopant material or an ionic liquid material. Examples of dopant materials include those described in Non-Patent Literature (J. Lee, et al., EcoMat vol. 5, p.e 12414 (2023)). The combination of cation and anion is not limited.

[0029] Examples of cations in ionic liquid materials include imidazolium salts, pyrrolidinium salts, pyridinium salts, piperidinium salts, ammonium salts, phosphonium salts, sulfonium salts, and phthalocyanine salts. Examples of anions include the following:

[0030] Furthermore, the compound that improves the current density may be a compound in which the anion is substituted with the cation, as shown in the following formula (Pc-TFSI).

[0031] This disclosure is preferable in that the ratio of the mass of the compound that improves the current density to the mass of the calixarene compound is 0.002 or more and 10 or less, in which the accumulation of charge resulting from the extraction and transfer of the increased charge due to the improved charge transport capacity can be suppressed.

[0032] This disclosure is preferable in that, if the ratio of the mass of the calixarene compound to the mass of the cyclic conjugated compound formed by the conjugation of the plurality of pyrrole rings is 0.01 or more and 0.5 or less, it is possible to suppress the accumulation of charge that occurs during the extraction and transfer of charge between the cyclic conjugated compound formed by the conjugation of the plurality of pyrrole rings.

[0033] This disclosure is preferable in that the charge transport capacity in the charge transport layer can be further improved if the ratio of the mass of the compound that improves the current density to the mass of the cyclic conjugated compound formed by the conjugation of the plurality of pyrrole rings is 0.0001 or more and 1 or less.

[0034] In the photoelectric conversion element disclosed herein, it is preferable that the charge transport layer contains a resin. Adding a resin is preferable because it suppresses the formation of voids in the charge transport layer, enhances adhesion between materials, improves charge transport ability, and suppresses stagnation that occurs during charge extraction and transfer. Furthermore, the SP value and functional groups of the resin can be appropriately selected to suppress the formation of voids.

[0035] Examples of functional groups include hydroxyl groups, carbonyl groups, ester groups, ether groups, carboxyl groups, methoxy groups, amino groups, sulfo groups, aldehyde groups, amide groups, halogens, sulfide groups, cyano groups, thienyl groups, pyridine, furan, pyrazole, imidazole, oxazole, and thiazole.

[0036] In the photoelectric conversion element of this disclosure, it is preferable that the resin is an insulating resin. If it is an insulating resin, the charge rectification required for the photoelectric conversion element can be maintained. The volume resistivity of the charge transport insulating resin is 1.0 × 10⁻⁶. ９ Preferably Ω·cm or more, and more preferably 1.0 × 10⁻⁶ １０ Ω・cm or more, 1.0×10 １５ A value of Ω·cm or less is more preferable.

[0037] This disclosure is preferable in that the ratio of the mass of the calixarene compound to the mass of the resin is 0.2 or more and 10 or less, as this can suppress the accumulation of charge that occurs during charge extraction and transfer.

[0038] Furthermore, this disclosure is preferable in that the charge transport capacity in the charge transport layer can be further improved if the ratio of the mass of the compound that improves the current density to the mass of the resin is 0.002 or more and 10 or less.

[0039] Furthermore, this disclosure is preferable in that the charge transport capacity in the charge transport layer can be further improved if the ratio of the mass of the cyclic conjugated compound, which is formed by the conjugation of multiple pyrrole rings, to the mass of the resin is 5 or more and 30 or less.

[0040] The thickness of the charge transport layer is preferably 5 nm to 800 nm. A thickness of 5 nm or more can be expected to suppress interlayer migration, and a thickness of 800 nm or less facilitates efficient charge transport to each electrode. More preferably, the thickness is 40 nm to 600 nm, and even more preferably 40 nm to 400 nm. By changing the thickness, the smoothness of the surface can be controlled, and an improvement in the charge transport capacity at the interface can be expected.

[0041] The photoelectric conversion element of the present disclosure has, for example, a charge transport layer between the photoelectric conversion layer and the first electrode, comprising a cyclic conjugated compound in which a plurality of pyrrole rings are conjugated together and a calixarene compound, and a surface modification layer between the charge transport layer and the first electrode.

[0042] As a result of their investigation, the inventors have found that having the above configuration results in a photoelectric conversion element with excellent photoelectric conversion efficiency. Although the details of why such high efficiency is obtained in this disclosure are not clear, it is thought to be as follows.

[0043] The charge transport layer comprises a cyclic conjugated compound and a calixarene compound, each consisting of multiple pyrrole rings with charge transport capabilities bonded together. By having a surface modification layer between the charge transport layer and the first electrode, charge retention in the charge transport layer is reduced, and charge can be efficiently transferred to the layer located opposite the photoelectric conversion layer. Furthermore, by appropriately configuring the wettability and interface states with the surface modification layer, charge can be transferred even more efficiently, improving the photoelectric conversion efficiency.

[0044] In the photoelectric conversion element of the present disclosure, the surface modification layer preferably comprises a dopant material, an ionic liquid material, or a passivation material, and more preferably, in order to further enhance the charge transfer capability at the interface, the surface modification layer is an ionic insulating material. Examples of passivation materials include the following:

[0045] The thickness of the surface modification layer is preferably 100 nm or less. A thickness of 100 nm or less facilitates good charge transport. More preferably, the thickness is 0.1 nm or more and 20 nm or less.

[0046] The composition of this disclosure contains a pigment which is a cyclic conjugated compound in which multiple pyrrole rings are conjugated together, a calixarene compound, a solvent, and a compound that improves current density or forms a surface modification layer. Each substance is as described above. The solvent can be any solvent that disperses and dissolves each substance, for example, 2-propanol or butanol.

[0047] When this composition is used to form a film for a photoelectric conversion element, the photoelectric conversion efficiency can be improved. The surface modification layer can also be formed by migrating the compounds in the above composition to the surface during coating. For surface migration, it is preferable that the compound forming the surface modification layer has an element or structure with low surface free energy, such as fluorine or siloxane.

[0048] As described above, the effects of this disclosure can be achieved through the synergistic interactions of each component.

[0049] The present disclosure will be described in detail below with reference to preferred embodiments. The present disclosure is not limited to the embodiments described below, and the scope of the present disclosure also includes modifications, improvements, etc., to the extent appropriate to the embodiments described below, based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the present disclosure.

[0050] In this specification, the term "layer" refers not only to layers with clear boundaries or flat, thin films, but also to layers with gradually changing concentrations of constituent elements, and layers that can combine with other layers to form complex, interwoven structures.

[0051] Furthermore, layer analysis can be performed, for example, by measuring using MS / NMR / XPS / IR / XRD / TEM / SEM / EDS / SPM to confirm the compounds contained in the layers and their composition.

[0052] Figure 1 is a schematic cross-sectional view showing the configuration of one embodiment of the photoelectric conversion element of the present disclosure. The photoelectric conversion element of the present disclosure has a first electrode 7, a second electrode 3, and a photoelectric conversion layer 5 containing a perovskite crystal disposed between the first electrode 7 and the second electrode 3, and a charge transport layer 6 between the photoelectric conversion layer 5 and the first electrode 7.

[0053] The substrate 2 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. One of the first electrode 7 and the second electrode 3 is a positive electrode and the other is a negative electrode, and current can be extracted by connecting the first electrode 7 and the second electrode 3 to an external circuit.

[0054] 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, generating electrons or holes. That is, the photoelectric conversion layer 5 generates an electric current between the first electrode 7 and the second electrode 3.

[0055] The electron transport layer 4 is a layer placed between the photoelectric conversion layer 5 and the two electrodes (second electrode 3 and first electrode 7), and may be omitted in some cases. Multiple electron transport layers 4 and photoelectric conversion layers 5 may be stacked on top of each other.

[0056] This configuration can also be called a tandem structure. Alternatively, the photoelectric conversion element may be fabricated on the substrate 2 in the following order: first electrode 7, charge transport layer 6, photoelectric conversion layer 5, electron transport layer 4, and second electrode 3.

[0057] The following describes each component constituting the photoelectric conversion element of this disclosure.

[0058] [Photoelectric Conversion Element] The photoelectric conversion element of the present disclosure is characterized by having a photoelectric conversion layer containing a perovskite structure crystal, a charge transport layer, or a photoelectric conversion layer containing a perovskite structure crystal, a charge transport layer, and a surface modification layer.

[0059] The photoelectric conversion element can be configured in either a forward layer configuration, where a layer with P-type semiconductor characteristics is formed after the photoelectric conversion layer, or an inverse layer configuration, where a layer with N-type semiconductor characteristics is formed after the photoelectric conversion layer. Furthermore, to improve the photoelectric conversion efficiency, a tandem type configuration in which photoelectric conversion elements are stacked may be used.

[0060] The photoelectric conversion elements to be stacked are not limited to the type of photoelectric conversion element, but also include perovskite solar cells that use perovskite crystals as the photoelectric conversion layer, as well as silicon solar cells and CIGS solar cells.

[0061] Methods for forming each layer of the photoelectric conversion element disclosed herein include coating methods and vapor deposition methods. Examples of coating methods include immersion coating, spin coating, spray coating, inkjet coating, meniscus coating, screen coating, roll coating, die coating, blade coating, curtain coating, and wire bar coating.

[0062] The coating method involves preparing the coating solution for each layer, applying them in the desired order, and then drying them. The appropriate method for each layer can be selected. The following describes each layer.

[0063] [Substrate] The photoelectric conversion element 1 of the present disclosure may include a substrate 2, for example, a transparent glass substrate made of soda-lime glass or alkali-free glass, a ceramic substrate, or a transparent plastic substrate. When light is taken in from the first electrode 7 side, the substrate 2 can be made of an opaque material, and when light is taken in from the second electrode 3 side, the substrate 2 is made of a transparent material.

[0064] [Electrodes] 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 alloys; lithium; magnesium; carbon; carbon nanotubes; aluminum; magnesium-silver mixtures; magnesium-indium mixtures; aluminum-lithium alloys; Al / Al ２ O ３ Examples include mixtures and Al / LiF mixtures.

[0065] Examples of transparent electrode materials include CuI, ITO (indium tin oxide), and SnO. ２Examples include conductive transparent materials and conductive transparent polymers such as AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), FTO (fluorine-doped tin oxide), and ATO (antimond-doped tin oxide). These materials may be used individually or in combination of two or more.

[0066] The first electrode 7 and the second electrode 3 are configured such that at least one electrode on the light incidence side is a transparent electrode, and the other electrode may be a transparent electrode or a reflective layer made of a light-reflective material, or a transparent electrode with a reflective layer on the side opposite to the light incidence side. When the first electrode 7 is on the light incidence side, the second electrode 3 may be a transparent electrode and the substrate 2 may be a reflective layer. The transparent electrode may also be a patterned electrode.

[0067] [Photoelectric Conversion Layer] The photoelectric conversion layer 5 has a perovskite crystal structure. The perovskite crystal structure used in this disclosure is preferably represented by the following general formula [1]. A ｏ B ｐ X ｑ [1]

[0068] In the above general formula [1], A is a cation, B is a cation, and X is an anion. o, p, and q satisfy 0 < o ≤ 10, 0 < p ≤ 10, and 0 < q ≤ 20, respectively. A, B, and X may be composed of a single material or two or more materials may be used in combination. Additives may be added within the range that the above general formula holds true.

[0069] The above general formula generally forms a three-dimensional perovskite crystal. However, if the constituent cation A is large enough to fit within the three-dimensional perovskite crystal, it can form a two-dimensional perovskite crystal, a 2.5-dimensional perovskite crystal possessing properties of both two and three dimensions, a two-layer crystal with three-dimensional and two-dimensional perovskite structures, or a crystal with a mixed three-dimensional / two-dimensional perovskite structure, all of which function as a photoelectric conversion layer.

[0070] A two-layer crystal of three-dimensional and two-dimensional perovskite refers to a crystal in which three-dimensional and two-dimensional perovskite crystals are stacked as independent, separate layers. A mixed three-dimensional / two-dimensional perovskite refers to a crystal in which regions or domains of both two-dimensional or 2.5-dimensional layered and three-dimensional perovskite crystals are mixed.

[0071] Crystals of two-dimensional perovskites or 2.5-dimensional perovskite structures may form RP (Ruddlesden-Popper), DJ (Dion-Jacobson), or ACI (Alternating Cautions in the Interlayer) type perovskite structures.

[0072] The type of cation A in the above general formula [1] is not particularly limited. A may or may not have substituents, and the following structural formulas are examples.

[0073] Furthermore, while the inorganic atoms are not particularly limited, lithium, cesium, sodium, potassium, and rubidium are preferred. These organic molecules or inorganic atoms may be used individually, or two or more may be used in combination.

[0074] In the general formula [1] above, B is a cation atom, and examples 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, bismuth, and silver are preferred from the viewpoint of the stability of the perovskite crystal structure. These atoms may be used individually or in combination of two or more.

[0075] In the general formula [1] above, X is a halogen or chalcogen atom, such as chlorine, bromine, iodine, oxygen, sulfur, selenium, tellurium, or polonium. These halogen or chalcogen atoms may be used individually or in combination of two or more.

[0076] In particular, halogen atoms are preferred because the inclusion of halogens in the structure makes the perovskite crystals more soluble in organic solvents, enabling their application to inexpensive printing methods and the like. Furthermore, iodine is more preferred because it narrows the energy band gap of the perovskite crystals.

[0077] Specifically, 3D perovskites, 2D perovskites, and mixed 3D / 2D perovskites are classified under MAPbI. ３ ya 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 , Cs ｘ (FA) １－ｘ PbI ３ MA ｘ (FA) １－ｘ PbI ３ MA ０．１７ FA ０．８３ Pb(I０．８３ 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 MA ０．７ ) 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 、(BA ０．９ PEA ０．１ ) ２ MA ４ Pb５ I １６ (BA ０．９ PEA ０．１ ) ２ MA ３ Pb ４ I １３ (BA) ２ MA ２ Pb ３ I １０ (BA) ２ MA ３ Pb ４ I １３ (BA) ２ MA ４ Pb ５ I １６ (BA) ２ MA ３ Pb ４ I １３ , CsSnBr ３ , CsSnI ３ FA ０．７５ MA ０．２５ Sn ０．９５ Ge ０．０５ I ３ , FAMASnGeI ３ FASnBr ３ FASnI ３ MA ２ Sn ３ I ８ ,MASnBr ３ ,MASnGeI ３ , MASnI ３ It is preferable.

[0078] Depending on the purpose, the A site, B site, or X site in the above general formula [1] may be adjusted to be too little or too much, and the combinations of x1 to x5 may be changed depending on the purpose. Examples of combinations of x1 to x5 are 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 also be included as the material for forming the perovskite crystal.

[0079]

[0080] The perovskite crystal described above preferably has a cubic crystal structure in which a metal atom B is located at the body center, organic molecules A are located at each vertex, and halogen atoms X are located at the face centers. Although the details are not clear, it is presumed that having such a structure allows the orientation of octahedra within the crystal lattice to change easily, thereby increasing the electron mobility in the perovskite crystal and improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0081] The perovskite crystal used in this disclosure is preferably a crystalline semiconductor. A crystalline semiconductor is a semiconductor in which the X-ray scattering intensity distribution can be measured and a scattering peak can be detected. Because the perovskite crystal is a crystalline semiconductor, the electron mobility in the perovskite crystal is increased, improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0082] The thickness of the photoelectric conversion layer according to this disclosure is preferably 5 nm or more and 2000 nm or less. If the thickness is 5 nm or more, light can be absorbed sufficiently, and if it is 2000 nm or less, the generated charge can be transported to each electrode. A more preferable lower limit is 50 nm or more, a more preferable upper limit is 1200 nm, an even more preferable lower limit is 100 nm, and an even more preferable upper limit is 1000 nm.

[0083] [Hole Transport Layer] In this disclosure, a hole transport layer may be provided between the charge transport layer and the first electrode 7. The material of the hole transport layer is not particularly limited, and examples 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, it is preferable that the material has an aromatic ring from the viewpoint of compatibility at the film interface, and Spiro-OMeTAD, PTAA, and phthalocyanine compounds are preferred.

[0084] Furthermore, the hole transport layer may contain dopants as additives to improve its charge transport capability. Examples of substances that can be used as dopants include lithium compounds such as bis(trifluoromethanesulfonyl)imide lithium, cobalt compounds such as [tris(2-(1H-pyrazole-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.

[0085] The thickness of the hole transport layer is preferably 1 nm to 1000 nm, more preferably 5 nm to 500 nm, and particularly preferably 10 nm to 200 nm.

[0086] [Electron Transport Layer] In the photoelectric conversion element of this disclosure, an electron transport layer 4 may be placed between the second electrode 3 and the photoelectric conversion layer 5, as shown in Figure 1.

[0087] The material of the electron transport layer 4 is not particularly limited and includes, for example, N-type conductive polymers, N-type low molecular weight organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surfactants, and more specifically, cyano group-containing polyphenylene vinylene, boron-containing polymers, vasocuproin, vasophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic acid compounds, fullerene compounds, perylene compounds, phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, titanium dioxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, and zinc sulfide.

[0088] The preferred lower limit for the thickness of the electron transport layer 4 is 1 nm, and the preferred upper limit is 2000 nm. If the thickness of the electron transport layer 4 is 1 nm or more, holes can be sufficiently blocked, and if it is 2000 nm or less, it will not become a resistance during electron transport, and the photoelectric conversion efficiency will be high. A more preferred lower limit for the thickness is 3 nm, a more preferred upper limit is 1000 nm, an even more preferred lower limit is 5 nm, and an even more preferred upper limit is 500 nm.

[0089] [Intermediate Layer] The photoelectric conversion element 1 may have one or more intermediate layers between each layer for the purpose of reducing energy gaps that hinder charge transfer or suppressing migration between layers. The intermediate layer contains either an inorganic compound or an organic compound.

[0090] Examples of inorganic compounds include Al compounds, Mo compounds, Ni compounds, Ti compounds, Sn compounds, and Zn compounds. Examples of organic compounds include fullerene compounds, phthalocyanine compounds, spirofluorene compounds, triphenylamine compounds, chrysene compounds, pyrene compounds, phthalocyanine compounds, carbazole compounds, fluorene compounds, phenylcyclohexane compounds, benzidine compounds, phenoxazine compounds, phenylenediamine compounds, thiocyanate compounds, butyral resins, acrylic resins, polycarbonate resins, polyester resins, polyvinyl acetal resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinylphenol resins, alkyd resins, polyvinyl alcohol resins, polyethylene oxide resins, polypropylene oxide resins, polyamide resins, polyamic acid resins, polyimide resins, polyamideimide resins, and cellulose resins. These compounds may be used individually or in combination of two or more. These compounds can also be mixed into layers or attached to surfaces by rinsing.

[0091] The thickness of the intermediate layer is preferably 5 nm to 800 nm. If the thickness is 5 nm or more, an effect of suppressing interlayer migration can be expected, and if the thickness is 800 nm or less, charge can be easily transported to each electrode. More preferably, it is 40 nm to 600 nm, and even more preferably 40 nm to 400 nm.

[0092] <Application Examples> [Photoelectric Conversion Device] The photoelectric conversion device of the present disclosure has a photoelectric conversion element of the present disclosure. A photoelectric conversion device can be configured by using multiple photoelectric conversion elements of the present disclosure. When multiple photoelectric conversion elements are connected together, such a photoelectric conversion device can also be called a photoelectric conversion cell or a photoelectric conversion module. The photoelectric conversion elements may be stacked with elements having different absorption wavelengths in order to increase the output voltage. The photoelectric conversion device also has a photoelectric conversion element of the present disclosure and an inverter. The inverter may be a converter that converts DC to AC. The photoelectric conversion device may have a power storage unit connected to the photoelectric conversion element. The power storage unit is not limited as long as it can store electricity. Examples include lithium-ion secondary batteries, all-solid-state batteries, and electric double-layer capacitors. To provide functions such as maintaining or increasing the amount of incident light, a surface that is resistant to water and dirt, or a function to collect or guide light may be added.

[0093] [Mobile Body] The mobile body of the present disclosure has a photoelectric conversion element of the present disclosure. Figure 2 is a schematic perspective view showing one embodiment of a mobile body equipped with the photoelectric conversion element of the present disclosure. The mobile body 30 has a photoelectric conversion element 31 of the present disclosure and a body 32 equipped with the photoelectric conversion element 31. The photoelectric conversion element 31 is positioned in a location on the body 32 that can receive ambient light. If the mobile body 30 is an automobile, the photoelectric conversion element 31 may be placed on the roof. The electrical energy obtained by the photoelectric conversion element 31 may be used to power the mobile body 30 or other electrical equipment. The electrical energy generated from the power of the mobile body 30 may be used to power the photoelectric conversion element 31. If the mobile body 30 is an automobile, the frictional energy generated by the brakes may be converted into electrical energy and used to control the photoelectric conversion element 31.

[0094] The mobile body 30 may be, for example, an automobile, a motorcycle, a railway vehicle, a ship, a satellite, an airplane, or a drone. The structure of the mobile body 32 is not particularly limited, but it is preferably made of a high-strength material.

[0095] [Building Material] The building material of the present disclosure has a photoelectric conversion element of the present disclosure. Figure 3 is a schematic perspective view showing one embodiment of the building material equipped with the photoelectric conversion element of the present disclosure. The building material 40 may be the roof of a building. The building material 40 of this embodiment has a photoelectric conversion element 41 of the present disclosure, a protective member 42 for protecting the photoelectric conversion element 41, a heat dissipation member 43, and exterior parts 44a and 44b.

[0096] The building material 40 of this disclosure may have a heat dissipation member 43 with a higher thermal conductivity than the photoelectric conversion element 41. Generally, when a building material equipped with a photoelectric conversion element is used on a roof or the like, the temperature of the photoelectric conversion element 41 may rise due to sunlight, which may reduce the photoelectric conversion efficiency. In this case, the reduction in photoelectric conversion efficiency can be reduced by using a heat dissipation member 43. Examples of heat dissipation members 43 include metals, alloys, liquid metals, and liquid resins.

[0097] Furthermore, the building material 40 of this disclosure may have exteriors 44a and 44b. Exteriors 44a and 44b may emit different colors or the same color. 44a and 44b may be composed of the same material or different materials. As the exterior material, paint or a transparent substrate may be used, and it is preferable to use one that has low light absorption and high heat shielding properties.

[0098] In addition to the above examples of applications, the following are some other examples of applications: Portable devices include calculators, sensors, and small solar panels. Wearable devices include eyeglasses, smartwatches, and portable medical devices. Sheet structures supported by multiple frames include tents, greenhouses, and truck beds. Fixed structures include road panels, floating panels, building materials that utilize the flexibility of the substrate, wall-type building materials, glass-type building materials, and mega solar panels.

[0099] <Method for Manufacturing a Photoelectric Conversion Element> The method for manufacturing a photoelectric conversion element according to the present disclosure includes the steps of forming a first electrode, forming a second electrode, forming a photoelectric conversion layer containing a perovskite crystal 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.

[0100] [Process for forming the first electrode and the process for forming the second electrode] In the process for forming the first electrode and the process for 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 deposition), and SPD (spray pyrolysis deposition). The materials of the first and second electrodes are as described above. When either the first electrode or the second electrode, or both, are transparent electrodes, the thickness of the transparent electrode is preferably 0.03 μm or more and 3 μm or less. When manufacturing solar cells, cutting may be performed between each process to form circuits. Examples of cutting may include mechanical patterning and laser patterning.

[0101] [Modularization Process] The elements with electrodes formed may be sealed. The material used for sealing is not limited to organic or inorganic materials. Specifically, examples include silicone rubber, resins having a siloxane skeleton, resins containing fluorine, silazane, and glass. Examples of sealing methods include coating, vapor deposition, or sealing by attaching a sheet. Furthermore, from the viewpoint of suppressing adhesion between elements that occurs when winding in a roll-to-roll manner, the surface of the sealed elements may be given a hairline finish.

[0102] [Step for forming the photoelectric conversion layer] The step for forming the photoelectric conversion layer may include a step of applying a liquid containing the photoelectric conversion layer material described above. Examples of application methods include spin coating, blade coating, slit die coating, screen printing, bar coating, mold making, print transfer, immersion and pull-up, inkjet, spray, and vacuum deposition.

[0103] From these options, a suitable choice is made depending on the characteristics of the photoelectric conversion layer to be fabricated, such as thickness control and orientation control. Annealing may be performed under reduced pressure or in an inert atmosphere (nitrogen or argon atmosphere) to remove the solvent or dispersion medium from the liquid containing the material of the applied photoelectric conversion layer.

[0104] The annealing temperature is preferably between 40°C and 300°C, and more preferably between 50°C and 150°C. Annealing is preferable because it can increase the contact area at the interface between the stacked layers, as the materials constituting each layer penetrate each other, thereby increasing the current.

[0105] [Step to form the charge transport layer] A preferred step for forming the charge transport layer is to apply a liquid containing the charge transport layer material described above. Examples of application methods include spin coating, blade coating, slit die coating, screen printing, bar coating, mold making, print transfer, immersion and pull-up, inkjet, spray, and vacuum deposition.

[0106] The present disclosure will be described in more detail below using examples and comparative examples. The present disclosure is not limited in any way by the following examples unless it exceeds the gist of the disclosure. In the following examples, "parts" refers to mass unless otherwise specified.

[0107] <Preparation of Particle 1> Step (1) Under a nitrogen flow atmosphere, 5.46 parts of orthophthalonitrile and 45 parts of α-chloronaphthalene were added to the reaction vessel, then heated to a temperature of 30°C and maintained at this temperature. Next, 3.75 parts of gallium trichloride were added at this temperature (30°C). The water concentration of the mixture at the time of addition was 150 ppm.

[0108] The temperature was then raised to 200°C. Next, the reaction was carried out at 200°C for 4.5 hours under a nitrogen flow atmosphere, then cooled, and the product was filtered when the temperature reached 150°C. The obtained filtrate was dispersed and washed with N,N-dimethylformamide at 140°C for 2 hours, and then filtered. The obtained filtrate was washed with methanol and dried to obtain chlorogallium phthalocyanine particles in a yield of 71%.

[0109] Step (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, and while stirring, the mixture was dropped dropwise into 620 parts of ice water to reprecipitation, and then filtered under reduced pressure using a filter press. A No. 5C filter (manufactured by Advantec Co., Ltd.) was used at this time.

[0110] 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 deionized water, and the filtration process using a filter press was repeated three times.

[0111] Finally, freeze-drying was performed to obtain hydroxygallium phthalocyanine particles (hydrated hydroxygallium phthalocyanine particles) with a solid content of 23% by mass in a yield of 71%. These hydroxygallium phthalocyanine particles were dried in a hyper-dry dryer (product name: HD-06R, frequency (oscillation frequency): 2455 MHz ± 15 MHz, manufactured by Nippon Biocon) to obtain hydroxygallium phthalocyanine (OHGaPc) particles (crystals) with a moisture content of 1.0% by mass or less.

[0112] Step (3) Five parts of the hydroxygallium phthalocyanine particles were mixed with five parts of N-methylformamide solvent. This mixture was dispersed for six hours using a sand mill (TSG-1 / 4G-4U, manufactured by Igarashi Machinery Manufacturing (now AIMEX), with a disc diameter of 70 mm and five discs) containing five glass beads, and then filtered and dried to obtain particle 1.

[0113] <Preparation of Resin Solution 1> 1.0 g of polyvinyl acetal resin (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd., glass transition temperature 71°C) was dissolved in 19 g of 2-propanol by stirring for 24 hours to obtain Resin Solution 1.

[0114] <Preparation of Resin Solution 2> 1.0 g of polymethyl methacrylate (trade name: PMMA, manufactured by Sigma-Aldrich, glass transition temperature 100°C) was dissolved in 19 g of chlorobenzene with stirring for 24 hours to obtain Resin Solution 2.

[0115] (Example 1) The photoelectric conversion element of Example 1 was obtained by the formation method described below.

[0116] [Formation of electron transport layer] An ITO-coated glass substrate was cleaned, and tin(II) oxide adjusted to 3% by mass was applied thereon by spin coating. Then, it was heated at 150°C for 30 minutes to form an electron transport layer on a thin film with a thickness of 15 nm.

[0117] [Formation of the photoelectric conversion layer] 22.4 mg of methylammonium bromide, 172 mg of formamidium iodide, and 576 mg of lead iodide were dissolved in 600 μL of N,N-dimethylformamide and 160 μL of dimethyl sulfoxide and stirred for 1 hour (Solution 1). Furthermore, 389.72 mg of cesium iodide was dissolved in 1000 μL of dimethyl sulfoxide and stirred for 1 hour (Solution 2).

[0118] Subsequently, 40 μL of dissolved cesium iodide solution (Solution 2) was added to Solution 1 to prepare a photoelectric conversion layer coating solution. By spin-coating this coating solution onto the electron transport layer, Cs ０．０５ (FA ０．８３ MA ０．１７ ) ０．９６ Pb(I ０．９５ Br ０．０５ ) ３ A photoelectric conversion layer with a thickness of 500 nm was formed.

[0119] [Formation of charge transport layer] 0.1 g of the aforementioned particles, 0.01 g of a calixarene compound (Japanese Patent Publication No. 2003-207913), 0.01 g of trioctylmethylammonium-bis(trifluoromethanesulfonyl)imide, and 10.6 g of 2-propanol were mixed together. 11 g of zirconia beads were enclosed in this mixture, and the mixture was dispersed in a paint shaker (manufactured by Toyo Seiki) for 3 hours.

[0120] Subsequently, 0.2 g of resin solution 1 was added, and paint shaker dispersion was performed again for 4 hours. A charge transport layer with a thickness of 150 nm was formed by spin coating this charge transport layer solution onto the photoelectric conversion layer.

[0121] [Formation of Hole Transport Layer] 0.15 g of the compound represented by the following formula (HTM-1) and 0.015 g of diphenyleneiodonium-tris(pentafluorophenyl)borane were weighed out and dissolved in chlorobenzene. This was then applied to the above charge transport layer by spin coating to form a hole transport layer with a thickness of 200 nm.

[0122] [Formation of the first electrode] A layer with a thickness of 80 nm and an area of ​​0.09 cm² is placed on the hole transport layer. ２ Gold electrodes were formed by vacuum deposition to obtain a photoelectric conversion element.

[0123] (Example 2) A photoelectric conversion element was obtained in the same manner as in Example 1, except that the charge transport layer and the surface modification layer were formed as described below. A hole transport layer was formed on the surface modification layer.

[0124] [Formation of charge transport layer] 0.1 g of the aforementioned particles 1 and 0.01 g of a calixarene compound (Japanese Patent Publication No. 2003-207913) were mixed with 10.6 g of 2-propanol, 11 g of zirconia beads were enclosed in this mixture, and the mixture was dispersed in a paint shaker (manufactured by Toyo Seiki) for 3 hours.

[0125] Subsequently, 0.2 g of resin solution 1 was added, and paint shaker dispersion was performed again for 4 hours to prepare the charge transport layer solution. A charge transport layer with a thickness of 150 nm was formed by spin coating this charge transport layer solution onto the photoelectric conversion layer.

[0126] [Formation of Surface Modified Layer] 0.143 g of diphenyleneiodonium-bis(trifluoromethanesulfonyl)imide was mixed and dissolved with 1.1 g of monochlorobenzene to obtain a coating for the surface modified layer. A 1 nm surface modified layer was formed by spin-coating this coating onto the charge transport layer.

[0127] (Example 3) A photoelectric conversion element was obtained in the same manner as in Example 1, except that the cyclic conjugated compound was changed to oxytitanium phthalocyanine particles.

[0128] (Example 4) A photoelectric conversion element was obtained in the same manner as in Example 1, except that the calixarene compound was changed to calix[4]arene represented by the following formula (CA-1).

[0129] (Example 5) A photoelectric conversion element was obtained in the same manner as in Example 1, except that resin solution 1 was changed to resin solution 2.

[0130] (Examples 6-46) In Example 1, a photoelectric conversion element was obtained in the same manner as in Example 1, except that the mass portion of the cyclic conjugated compound, the mass portion of the calixarene compound, the compound that improves the current density, and the mass portion of the resin solution were changed as shown in Table 2.

[0131] (Examples 47-51) In Example 2, a photoelectric conversion element was obtained in the same manner as in Example 2, except that the surface modification layer was changed as shown in Table 2.

[0132] (Comparative Example 1) A photoelectric conversion element was obtained in the same manner as in Example 2, except that a surface modification layer was not formed.

[0133] [Evaluation] The photoelectric conversion efficiency of the photoelectric conversion elements obtained in Examples 1 to 51 and Comparative Example 1 was measured. The measurement result for Example 1 was set to 100, and the relative values ​​are shown in Table 2 below.

[0134]

[0135]

[0136] This disclosure is not limited to the embodiments described above, and various modifications and alterations are possible without departing from the spirit and scope of this disclosure. Accordingly, the following claims are attached to make the scope of this disclosure public.

[0137] This application claims priority based on Japanese Patent Application No. 2024-166621, filed on 25 September 2024, and Japanese Patent Application No. 2025-122562, filed on 22 July 2025, and all of the contents of those applications are incorporated herein by reference.

[0138] 1. Photoelectric element 2. Substrate 3. Second electrode 4. Electron transport layer 5. Photoelectric layer 6. Charge transport layer 7. First electrode

Claims

1. A photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer containing a perovskite crystal disposed between the first electrode and the second electrode, wherein a charge transport layer is provided between the photoelectric conversion layer and the first electrode, the charge transport layer comprises a cyclic conjugated compound formed by the conjugation bonding of a plurality of pyrrole rings and a calixarene compound, the charge transport layer contains a compound that improves current density, or the photoelectric conversion element has a surface modification layer between the charge transport layer and the first electrode.

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

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

4. The photoelectric conversion element according to any one of claims 1 to 3, wherein the cyclic conjugated compound is a compound having the structure shown by the following formula (Pc-1). (In the above formula (Pc-1), M is H ２ (Preferably, metal atoms having ligands or metal atoms without ligands.) 5. The photoelectric conversion element according to claim 4, wherein M is gallium, aluminum, titanium, iron, or silicon having a ligand.

6. The photoelectric conversion element according to any one of claims 1 to 5, wherein the cyclic conjugated compound is a hydroxygallium compound or a chlorogallium phthalocyanine compound.

7. The photoelectric conversion element according to any one of claims 1 to 6, wherein the calixarene compound is represented by the following formula (A). (In the formula (A), R １ to R ５ are each independently within each repeating unit and each independently for every n repeating units, R １ represents a hydrogen atom or an alkyl group, and R ２ represents a substituted or unsubstituted alkylene group, and R ３ to R ５ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted -Y-Ar group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group, and among R ３ to R ５ at least one is a -Y-Ar group having a substituent. The -Y- represents -CH=N-, -CH=CH-, or -N=N-, and the Ar is a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group. n is an integer of 3 or more and 20 or less.) 8. The photoelectric conversion element according to claim 7, wherein n is 4 or 8.

9. The aforementioned R ４ The photoelectric conversion element according to claim 7 or 8, wherein each of the n repeating units is independently a nitrophenylazo group or a dinitrophenylazo group.

10. The photoelectric conversion element according to any one of claims 1 to 9, wherein the molecular weight of the calixarene compound is 10,000 or less.

11. The photoelectric conversion element according to any one of claims 1 to 10, wherein the calixarene compound is a mixture of the compound represented by the following formula (C-1), the compound represented by the following formula (C-2), the compound represented by the following formula (C-3), and the compound represented by the following formula (C-4).

12. The photoelectric conversion element according to any one of claims 1 to 11, wherein the compound that improves the current density is a dopant material or an ionic liquid material.

13. The photoelectric conversion element according to any one of claims 1 to 12, wherein the ratio of the mass of the compound that improves the current density to the mass of the calixarene compound is 0.002 or more and 10 or less.

14. The photoelectric conversion element according to any one of claims 1 to 13, wherein the ratio of the mass of the calixarene compound to the mass of the cyclic conjugated compound is 0.01 or more and 0.5 or less.

15. The photoelectric conversion element according to any one of claims 1 to 14, wherein the ratio of the mass of the compound that improves the current density to the mass of the cyclic conjugated compound is 0.0001 or more and 1 or less.

16. The photoelectric conversion element according to any one of claims 1 to 15, wherein the charge transport layer contains a resin.

17. The photoelectric conversion element according to claim 16, wherein the resin is an insulating resin.

18. The photoelectric conversion element according to claim 16 or 17, wherein the ratio of the mass of the calixarene compound to the mass of the resin is 0.2 or more and 10 or less.

19. The photoelectric conversion element according to any one of claims 16 to 18, wherein the ratio of the mass of the compound that improves the current density to the mass of the resin is 0.002 or more and 10 or less.

20. The photoelectric conversion element according to any one of claims 16 to 19, wherein the ratio of the mass of the cyclic conjugated compound to the mass of the resin is 5 or more and 30 or less.

21. The photoelectric conversion element according to any one of claims 1 to 20, wherein the surface modification layer comprises a dopant material, an ionic liquid material, or a passivation material.

22. A photoelectric conversion device having a photoelectric conversion element according to any one of claims 1 to 21.

23. A mobile body having a photoelectric conversion element according to any one of claims 1 to 21.

24. A building material having a photoelectric conversion element according to any one of claims 1 to 21.

25. A composition comprising a pigment which is a cyclic conjugated compound in which multiple pyrrole rings are conjugated together, a calixarene compound, a solvent, and a compound which improves current density or forms a surface modification layer.

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