Organic-inorganic composite material, method for producing same, circularly polarized light detection element, wavelength shifting method, photovoltaic element, and solar cell

Abstract

This organic-inorganic composite material comprising chiral molecules and a plurality of inorganic chains consisting of a substance having an octahedral structure and constituting pseudo linear structures, wherein: the substance and the chiral molecules constitute a compound A2BX6 composed of three kinds of ions A, B, and X; the ions B and the ions X form a plurality of units having the octahedral structure; the octahedral structure of adjacent units include the pseudo linear structures along the orientation of the chiral molecules without sharing any one of the vertices and surfaces with each other; and the ions B in the octahedral structure are tetravalent metal ions.

Description

Organic-inorganic composite material, its manufacturing method, circularly polarized light detection element, wavelength shift method, photovoltaic element, and solar cell

[0001] This disclosure relates to an organic-inorganic composite material, a manufacturing method thereof, a circular polarization detection element, a wavelength shift method, a photovoltaic element, and a solar cell. This application claims priority to Japanese Patent Application No. 2024-88896, filed on May 31, 2024, the contents of which are incorporated herein by reference.

[0002] Polarization image sensors are known that utilize polarization phenomena to visualize information about the structure and properties of various objects. A polarization image sensor includes a polarizer array with multiple groups of four polarizers with different polarization directions, and a photodiode array with multiple photodiodes arranged facing each polarizer group. Linearly polarized light signals transmitted through the four polarizers in the same group are converted into electrical signals by the photodiodes and output as information for one pixel. From the linearly polarized light output signal, three Stokes parameters can be calculated by combining the sum and difference of the intensities of orthogonal polarization components, and these parameters can be used to quantify the state of the transmitted light.

[0003] However, it is difficult to visualize states such as birefringence and stress distribution observed when an object is bent using only the three Stokes parameters obtained from linearly polarized light. It is known that these states can be visualized using Stokes parameters calculated from the intensity of circularly polarized light, and a technology for detecting circularly polarized light is needed. Furthermore, detecting circularly polarized light using the polarization image sensor described above requires an additional wave plate, which significantly reduces sensitivity. Therefore, a technology for directly detecting circularly polarized light is needed.

[0004] Patent Document 1 discloses a thin film for detecting circularly polarized light, which is made of a perovskite-type material and includes a plurality of inorganic layers constituting a layered structure and / or a plurality of inorganic chains constituting a chain structure, and chiral molecules contained in at least a portion of the boundaries between adjacent inorganic layers and / or adjacent inorganic chains, wherein the chiral molecules are either S-type chiral molecules or R-type chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, and the crystal structure of the perovskite-type material is oriented in a predetermined direction.

[0005] Further, conventional photovoltaic materials that generate an electric potential at a heterointerface where different substances come into contact with each other (for example, a p-n junction interface, or an interface between a light absorbing layer and an electron / hole transport layer) are known, and various photoelectric conversion apparatuses and devices such as solar cells have been developed using such conventional photovoltaic materials.

[0006] International Publication No. 2021 / 241554

[0007] Currently, there is a demand for thin films that have high circularly polarized light absorption intensity in the visible light region over a wider wavelength range than the thin film of Patent Document 1. In addition, there is a demand for novel photovoltaic materials that generate an electromotive force in a single material without the presence of a potential difference interface (an interface where different materials come into contact, such as a p-n junction), and further, that do not depend on the band gap, and therefore have no theoretical upper limit to their photoelectric conversion efficiency.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide an organic-inorganic composite material that induces or has high circularly polarized light absorption intensity over a wide wavelength range in the visible light region, a method for producing the same, a circularly polarized light detection element, and a method for shifting the circularly polarized light absorption wavelength to longer wavelengths. The present invention also aims to provide a photovoltaic element and a solar cell that use a novel photovoltaic material, and is expected to reduce the burden on solar cell manufacturing processes and dramatically improve their performance.

[0009] In order to solve the above problems, the present invention proposes the following means: (1) An organic-inorganic composite material according to aspect 1 of the present invention is an organic-inorganic composite material for detecting circularly polarized light or generating bulk photovoltage, comprising: a plurality of inorganic chains made of a substance having an octahedral structure and constituting a pseudo-linear structure; and chiral molecules, wherein the chiral molecules are contained in at least a part of the boundaries between adjacent inorganic chains, the chiral molecules are either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, the octahedral structure of the substance is oriented in a certain direction, and the substance and the chiral molecules are formed by a compound A composed of three types of ions A, B, and X. ２ BX ６The ion B and the ion X form a plurality of units having the octahedral structure, and the octahedral structures of adjacent units do not share any vertices or faces, but comprise a pseudo-linear structure aligned with the orientation of the chiral molecules, and the ion B in the octahedral structure is a tetravalent metal ion. (2) Aspect 2 of the present invention relates to the organic-inorganic hybrid material of Aspect 1, wherein the tetravalent metal ion may be a tetravalent tellurium ion. (3) Aspect 3 of the present invention relates to the organic-inorganic hybrid material of Aspect 1, wherein the ion A is an aromatic compound containing an ethylammonium ion, and the tetravalent metal ion may be a tetravalent tellurium ion. (4) Aspect 4 of the present invention relates to the organic-inorganic hybrid material of Aspect 3, wherein the aromatic compound may be a polycyclic aromatic compound. (5) Aspect 5 of the present invention relates to the organic-inorganic hybrid material of Aspect 4, wherein the aromatic ring of the polycyclic aromatic compound may be a naphthalene ring or an anthracene ring. (6) Use of Aspect 6 of the present invention is the use of the organic-inorganic composite material of any one of Aspects 1 to 5 for circular polarization detection or bulk photovoltage generation. (7) A production method of Aspect 7 of the present invention is the production method of the organic-inorganic composite material of Aspect 1, comprising: a first step of synthesizing a raw material BX of the precursor of the substance having an octahedral structure, which is composed of the ion X and the tetravalent metal ion that is the ion B; a second step of dissolving the raw material BX in a solvent to prepare a first solution; a third step of synthesizing a halide AX of the chiral molecule composed of the ion X and the ion A; a fourth step of dissolving the halide AX synthesized in the third step in the first solution to prepare a second solution; a fifth step of applying the second solution to a substrate by spin coating to form a coating film composed of the precursor on the substrate; and a fifth step of heating the resulting coating film to form a compound A. ２ BX ６ and a sixth step of forming a thin film comprising the compound A. ２ BX ６(8) A manufacturing method of Aspect 8 of the present invention is a manufacturing method of an organic-inorganic composite material of Aspect 1, comprising: a first step of synthesizing a raw material BX of the precursor of the substance having the octahedral structure, which is composed of the ion X and the tetravalent metal ion that is the ion B; a second step of dissolving the raw material BX in a solvent to prepare a first solution; a third step of synthesizing a halide AX of the chiral molecule composed of the ion X and the ion A; a fourth step of dissolving the halide AX synthesized in the third step in the first solution to prepare a second solution; and a fourth step of gradually cooling the second solution to change it from a dissolved state to a crystallized solid state and precipitate a crystal, thereby producing the compound A. ２ BX ６ and a fifth step of forming a crystal having the compound A. ２ BX ６ The ion B in the above-mentioned formula (9) Aspect 9 of the present invention is the production method of Aspect 7 or Aspect 8, wherein the ion A is an aromatic compound containing an ethylammonium ion, and the tetravalent metal ion may be a tetravalent tellurium ion. (10) Aspect 10 of the present invention is the production method of Aspect 9, wherein the aromatic compound may be a polycyclic aromatic compound. (11) Aspect 11 of the present invention is the production method of Aspect 10, wherein the aromatic ring of the polycyclic aromatic compound may be a naphthalene ring or an anthracene ring. (12) A circular polarization detection element of Aspect 12 of the present invention includes the organic-inorganic composite material of any one of Aspects 1 to 5 of the present invention. (13) A wavelength shift method of Aspect 13 of the present invention is a wavelength shift method for shifting the circularly polarized light absorption wavelength detected by a circular polarization detection element to a longer wavelength, comprising: ２ BX ６the thin film comprises, as a light receiving layer of a circular polarization detection element, a thin film containing only tetravalent metal ions as ions B contained within the octahedral structure of the thin film, the thin film comprising: a plurality of inorganic chains made of a substance having the octahedral structure and constituting a pseudo-linear structure; and chiral molecules, the chiral molecules being contained in at least a portion of the boundaries between adjacent inorganic chains, the chiral molecules being either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, the octahedral structure being oriented in a certain direction, and the substance and the chiral molecules being compound A composed of three types of ions A, B, and X. ２ BX ６ wherein the ions B and X form a plurality of units having the octahedral structure, and the octahedral structures of adjacent units do not share any vertex or face, and comprise a pseudo-linear structure that follows the orientation of the chiral molecules. (14) A photovoltaic element of Aspect 14 of the present invention comprises the organic-inorganic composite material of any one of Aspects 1 to 5 of the present invention. (15) A solar cell of Aspect 15 of the present invention comprises the photovoltaic element of Aspect 14.

[0010] According to the above-mentioned aspects related to the circular polarization detection element of the present invention, it is possible to provide an organic-inorganic composite material that induces or has a high circularly polarized light absorption intensity over a wide wavelength range in the visible light region, a method for producing the same, a circularly polarized light detection element, and a method for wavelength shifting the circularly polarized light absorption wavelength. Furthermore, the present invention can provide a photovoltaic element and a solar cell using a novel photovoltaic material, which can reduce the burden on the solar cell process and dramatically improve its performance.

[0011] 1 shows a cross-sectional view of a thin film according to one embodiment of the present invention. (a) in the figure is a cross-sectional view of a thin film containing S-1-NEA as a chiral molecule, (b) in the figure is a cross-sectional view of a thin film containing R-1-NEA as a chiral molecule, and (c) in the figure shows an octahedral structure. The arrows in (a) and (b) indicate the direction of current resulting from the thin film absorbing circularly polarized light or light containing circularly polarized light irradiated onto the thin film. This is a schematic cross-sectional view of a photovoltaic element according to one embodiment of the present invention. This is a flowchart of a method for producing an organic-inorganic composite material comprising a crystal according to one embodiment of the present invention. This is a flowchart of a method for producing an organic-inorganic composite material comprising a thin film according to one embodiment of the present invention. This is an X-ray diffraction pattern of Example 3 (single crystal 1). This is an X-ray diffraction pattern of Example 1 (thin film 1). This is an absorption spectrum of Example 4 (single crystal 2) (top panel) and circular dichroism spectra of Examples 3 and 4 (single crystals 1 and 2) (bottom panel). 1 shows the circular dichroism spectra of Example 1 (thin film 1) and Example 2 (thin film 2). FIG. 2 shows the photoelectric conversion characteristics of Examples 3 and 4 (single crystal bodies 1 and 2).

[0012] Hereinafter, an organic-inorganic composite material, a manufacturing method thereof, a circular polarization detection element, a wavelength shift method, a photovoltaic element, and a solar cell according to embodiments of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component element may not necessarily be the same as in reality. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate modifications can be made within the scope of the present invention.

[0013] FIG. 1 is a cross-sectional view schematically illustrating the configuration of an organic-inorganic composite material 100 according to one embodiment of the present invention. The organic-inorganic composite material 100 is a thin film for detecting circularly polarized light or generating bulk photovoltaic power. It is composed of a substance 101 having a hexacoordinated octahedral structure (hereinafter, sometimes simply referred to as an "octahedral structure") and includes multiple inorganic chains 102 forming a pseudo-linear structure and chiral molecules 103. The organic-inorganic composite material 100 is an organic-inorganic composite material to which chirality has been imparted. Here, the octahedral structure refers to a molecular structure in which six ligands are symmetrically arranged around a central atom, forming the vertices of a regular octahedron (i.e., a hexacoordinated octahedral structure, see, for example, FIG. 1(c)). While FIG. 1 illustrates an amino group (specifically, an ethylamino group) as the functional group of the chiral molecule 103, the functional group used in the present invention is not limited to the ethylamino group.

[0014] Each inorganic chain 102 is, for example, a chain structure in which the substances 101 form a pseudo-linear structure. The pseudo-linear structure refers to a structure in which the substances 101 are arranged in a line in a certain direction (arrangement direction) as shown in Figure 1. The octahedral structure of the substances 101 is oriented in a certain direction. Here, "oriented in a certain direction" means, for example, that the substances 101 exist in a substantially regular and uniform state in a direction determined within a specific range. The spacing between the substances 101 is not particularly limited, but it is preferable that they are arranged regularly.

[0015] The substance 101 and the chiral molecule 103 are a compound A consisting of three types of ions A, B, and X (i.e., three types of ions A, B, and X). ２ BX ６ Ions B and X form a plurality of units having an octahedral structure. Specifically, ions B and X form a plurality of units (BX ６ ) ４－The octahedral structures of adjacent units do not share any vertices or faces. Ion B is located at the center of the octahedron, and ion X is located at a vertex of the octahedron. Ion A is located at a position circumscribing the octahedral structure of each unit. Ion A is a chiral molecule 103.

[0016] The inorganic chains 102 have a pseudo-linear structure that follows the orientation of the chiral molecules 103, with the octahedral structures not sharing any vertices or faces. In other words, the chiral molecules 103 surround the inorganic chains 102. This allows the inorganic chains 102 to be endowed with the ability to directly detect circularly polarized light. Furthermore, the fact that the octahedral structures do not share any vertices or faces can enhance the ability to absorb circularly polarized light in the visible light region (e.g., 350 nm to 800 nm, preferably 400 nm to 700 nm). Furthermore, bulk photovoltaic power can be generated. The fact that the octahedral structures do not share any vertices or faces can be determined by structural analysis using X-ray diffraction measurements (see, for example, Figures 5 and 6).

[0017] Ion A is a chiral molecule 103. The chiral molecule 103 has one or more asymmetric carbon atoms. At the boundary 104 between adjacent inorganic chains 102, the chiral molecule 103 is bonded to the inorganic chain 102 (the substance 101 that constitutes the inorganic chain 102) via a functional group (an ethylamino group in FIG. 1 ) covalently bonded to one asymmetric carbon atom that constitutes the chiral molecule 103. That is, the chiral molecule 103 is bonded to the substance 101 via a functional group (bonding functional group) covalently bonded to the asymmetric carbon atom of the chiral molecule 103. This allows for the formation of a structure in which the chiral molecule 103 surrounds the inorganic chain 102.

[0018] The chiral molecule 103 has, for example, an aromatic ring having a site capable of bonding to an asymmetric carbon atom, a binding functional group that bonds to the substance 101, and an asymmetric carbon atom that bonds to the aromatic ring and the binding functional group. The chiral molecule 103 is preferably an aromatic compound containing an ethylammonium ion. The molecular weight of the chiral molecule 103 is preferably, for example, 100 to 1000. The aromatic ring of the chiral molecule 103 may further have a substituent. The substituents other than the binding functional group are not particularly limited. The number of substituents on the aromatic ring of the chiral molecule 103 is, for example, 1 to 2. The functional group that bonds to the asymmetric carbon atom other than the aromatic ring and the binding functional group of the chiral molecule 103 is not particularly limited, and may be, for example, a hydrogen atom or an alkyl group.

[0019] The binding functional group of the chiral molecule 103 is a substituent that can have an electric charge, and the substituent and the substance 101 can form a bond via a halogen ion (ion X). An example of the binding functional group is an amino group. Specifically, an alkylamino group is preferable, and an ethylamino group is more preferable. The amino group (NH ３ ＋ ) is, for example, (TeI ６ ) ４－ I － By combining with (TeI ６ ) ４－ Chirality is generated in the inorganic chain 102 consisting of the above, and new properties such as circularly polarized light absorption ability and bulk photovoltaic generation ability are exhibited.

[0020] The chiral molecule 103 is preferably a polycyclic aromatic compound having one or more benzene rings, preferably two or more. It is more preferable that the chiral molecule 103 is a polycyclic aromatic compound having three or more benzene rings. If the aromatic ring of the chiral molecule 103 is an aromatic ring (fused aromatic ring) having a structure (covalent structure) in which one side of the benzene ring is shared, such as a naphthalene ring or an anthracene ring, this is preferable because it increases the circularly polarized light absorption intensity, bulk photovoltaic generation ability, etc. The aromatic ring is preferably a naphthalene ring or an anthracene ring.

[0021] Chiral molecules 103 exist in the R-configuration and the S-configuration. Chiral molecules 103 in the R-configuration or the S-configuration strongly absorb either right-handed or left-handed circularly polarized light. Here, an R-configuration is one in which four different bonding groups are bonded to an asymmetric carbon, with the one with the smallest atomic number placed furthest away and the remaining three bonding groups arranged clockwise from largest to smallest atomic number, and an S-configuration is one in which they are arranged counterclockwise. Examples of R-configurations include R-(+)-1-(1-naphthyl)ethylamine shown in the following formula (1) and R-(+)-1-(2-naphthyl)ethylamine shown in the following formula (3). Examples of S-configurations include S-(-)-1-(1-naphthyl)ethylamine shown in the following formula (2) and S-(-)-1-(1-naphthyl)ethylamine shown in the following formula (4).

[0022]

[0023]

[0024]

[0025]

[0026] The chiral molecules 103 are either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other. When the chiral molecules 103 are either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, a chiral structure of R- or S-configuration can be induced in the substance 101, and circularly polarized light can be directly detected.

[0027] The ion B is a tetravalent metal ion. An example of the tetravalent metal ion is a tetravalent tellurium (Te) ion. This allows for the production of an organic-inorganic composite material 100 with high circularly polarized light absorption intensity over a wide wavelength range in the visible light region. The ion X may be, for example, a halogen ion. An example of the halogen ion is F. － , Cl － ,Br － and I － The halogen ions include I － is preferred.

[0028] In FIG. 1, a case is illustrated where chiral molecules 103 form an organic layer 105 at the boundary portion 104 and the organic layer 105 covers around the inorganic chain 102. In the organic-inorganic composite material 100, at least a part of the boundary portion 104 between adjacent inorganic chains 102 contains the chiral molecules. Thereby, the substance 101 is regularly arranged to form a pseudo-linear structure. The aromatic rings of the chiral molecules 103 bonded to the substance 101 may be arranged in a certain direction. When the organic-inorganic composite material 100 is used for a circularly polarized light detecting element, a photovoltaic element, etc., from the viewpoint of facilitating the flow of current in the thickness direction D, the thickness of the organic-inorganic composite material 100 is preferably about 100 nm or more and 500 nm or less.

[0029] In order to cause the irradiated light to be absorbed by the substance 101, from the viewpoint of efficiently transmitting the irradiated light, the surface roughness Ra (arithmetic mean roughness) of each organic-inorganic composite material 100 is preferably 1 nm or more and 30 nm or less. Further, if the arithmetic mean roughness Ra of the organic-inorganic composite material 100 is 30 nm or less, the leakage of the circularly polarized light detecting element 120 described later can be suppressed. The arithmetic mean roughness Ra can be measured, for example, using an atomic force microscope (AFM). When measuring using an atomic force microscope, for example, an atomic force microscope manufactured by Shimadzu Corporation is used, and the arithmetic mean roughness Ra can be obtained from an observation image obtained by setting the scanning range and scanning mode to appropriate values (specifically, for example, scanning mode: dynamic mode) for measurement.

[0030] Further, as the absorption intensity per unit thickness of the organic-inorganic composite material 100, for example, 50,000 cm －１ or more and 500,000 cm －１ or less can be mentioned. Note that the absorption intensity per unit thickness is the value of the peak wavelength of the peak with the highest absorption intensity. The measurement of the absorption intensity of the organic-inorganic composite material 100 shall be performed by a transmission method. With such an absorption intensity, the substance 101 can efficiently absorb the irradiated light.

[0031] (Circular Polarization Detection Element) A circular polarization detection element including the organic-inorganic composite material 100 is mainly formed by laminating an anode layer, the organic-inorganic composite material 100, and a cathode layer in this order. At least one of the anode layer and the cathode layer has optical transparency so that the substance 101 in the thin film absorbs light (circularly polarized light). The anode layer is formed on one side in the thickness direction of the organic-inorganic composite material 100, for example, by SnO ２ , TiO ２ The positive electrode layer may be bonded to the other side in the thickness direction of the organic-inorganic composite material 100 via a negative electrode-side adhesive layer (electron transport layer) made of, for example, BCP (Bathocuproine (registered trademark)), spiro-MeOTAD, TPD, or the like. When the negative electrode layer is optically transparent, the negative electrode-side adhesive layer is also optically transparent. When the positive electrode layer is optically transparent, the positive electrode-side adhesive layer is also optically transparent.

[0032] In the circular polarization detection element, the inorganic chains 102 constituting the organic-inorganic composite material 100 have a crystalline structure, and therefore the light absorption of the organic-inorganic composite material 100 is large (for example, absorption intensity at a wavelength of 375 nm: approximately 50,000 cm －１ The organic-inorganic composite material 100 has a high conductivity (carrier diffusion length of approximately 1 μm or more) and a high conductivity (carrier diffusion length of approximately 1 μm or more). Therefore, when the light irradiated onto the organic-inorganic composite material 100 is circularly polarized or contains circularly polarized light, a current due to the absorbed circularly polarized light can be detected. Note that by using only R- or S-configuration chiral molecules, a chiral structure with an R- or S-configuration can be induced in the perovskite structure, which selectively absorbs right-handed circularly polarized light or left-handed circularly polarized light, and the resulting current can be detected (see the arrows in Figures 1(a) and (b)).

[0033] 2, a photovoltaic element 120A including an organic-inorganic composite material (thin film) 100A is mainly formed by laminating an anode layer 106A, an organic-inorganic composite material 100A, and a cathode layer 107A in this order. The organic-inorganic composite material 100A is a single crystal. At least one of the anode layer 106A and the cathode layer 107A is optically transparent so that the substance 101 absorbs light (circularly polarized light).

[0034] In the photovoltaic element 120A, the inorganic chains 102 constituting the organic-inorganic composite material 100A are single crystals, and therefore the light absorption of the organic-inorganic composite material 100A is large (for example, absorption intensity at a wavelength of 375 nm: approximately 50,000 cm －１ The organic-inorganic composite material 100A has a high conductivity (carrier diffusion length of about 1 μm or more) and a high conductivity (carrier diffusion length of about 1 μm or more). Therefore, when the light irradiated onto the organic-inorganic composite material 100A is circularly polarized or contains circularly polarized light, a current resulting from the absorbed circularly polarized light can be detected, and the bulk photovoltaic generation capacity can be increased. Note that by using only R- or S-configuration chiral molecules, a chiral structure of R- or S-configuration can be induced in the perovskite structure, and right-handed circularly polarized light or left-handed circularly polarized light can be selectively absorbed, and the resulting current can be detected.

[0035] (Method for producing an organic-inorganic composite material consisting of a single crystal) Next, a method for producing an organic-inorganic composite material consisting of a single crystal according to the present disclosure will be described. FIG. 3 is a flowchart of the production method according to the present disclosure. The production method according to the present disclosure includes: (1) a first step S1A of synthesizing a raw material BX, which is a precursor of a substance 101 having an octahedral structure and composed of an ion X and a tetravalent metal ion, which is an ion B; (2) a second step S2A of dissolving the raw material BX in a solvent to prepare a first solution; (3) a third step S3A of synthesizing a halide AX of a chiral molecule 103 composed of an ion X and an ion A; (4) a fourth step S4A of dissolving the halide AX synthesized in the third step S3A in the first solution to prepare a second solution; and (5) a fourth step S4A of gradually cooling the second solution to change it from a dissolved state to a crystalline solid state and precipitate crystals, thereby synthesizing the compound A. ２ BX ６ and a fifth step S5A of forming a crystal having compound A. ２ BX ６ The ion B in the formula (I) includes only tetravalent metal ions, and the tetravalent metal ion is preferably tellurium.

[0036] (First Step S1A) In the first step S1A, a raw material BX of the precursor of the substance 101 having an octahedral structure composed of ion X and ion B, a tetravalent metal ion, is synthesized. The precursor of the substance 101 refers to a substance at a stage before the substance 101 is produced. The raw material BX of the precursor is a halide of ion B. An example of the halide of ion B is TeCl. ４ , TeBr ４ , TeI ４ and the like. The halide of ion B can also be used as a mixture containing hydrogen halides such as hydrogen chloride, hydrogen bromide, and hydrogen iodide. Each raw material may be commercially available, or may be synthesized using a synthesis method in accordance with a conventional method in the technical field. When a commercially available product is used as raw material BX, the first step S1A can be skipped by the purchaser of the commercially available product, since it is used in the process of producing the commercially available product.

[0037] (Second Step S2A) In the second step S2A, the raw material BX synthesized in the first step S1A is dissolved in a solvent to prepare a first solution. The solvent is not particularly limited as long as it can dissolve the raw material BX. Examples of the solvent include water, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and γ-butyrolactone. Water and dimethylformamide are particularly preferred as the solvent.

[0038] When dissolving the raw material BX in a solvent, it is advisable to heat the solvent as needed. The heating temperature of the solvent is, for example, 30°C to 100°C. The heating temperature is equal to or lower than the boiling point of the solvent. By keeping the temperature range from 60°C to 80°C, the solubility of the raw material BX can be further increased.

[0039] The concentration of the raw material BX in the first solution is preferably 15% by mass to 40% by mass, and a thin film of a precursor suitable for forming the substance 101 can be formed.

[0040] (Third Step S3A) In the third step S3A, a halide AX of a chiral molecule 103 composed of an ion X and an ion A is synthesized. Here, the ion X is Cl, Br, or I. The chiral molecule 103, which is the ion A, preferably has a functional group capable of forming a salt with a halogen. Examples of functional groups capable of forming a salt with a halogen include alkylamino groups such as a methylamino group and an ethylamino group, and aminocarboxylic acid groups. Examples of the chiral molecule 103 before halogenation include the aforementioned R-(+)-1-(1-naphthyl)ethylamine, R-(+)-1-(2-naphthyl)ethylamine, S-(-)-1-(1-naphthyl)ethylamine, and S-(-)-1-(1-naphthyl)ethylamine. The halogenated chiral molecule 103 may be commercially available or may be synthesized using a synthesis method based on a conventional method in the art. When a commercially available product is used as the halide AX, the third step S3A is used in the process of producing the commercially available product, and therefore, the purchaser of the commercially available product can skip this step.

[0041] (Fourth Step S4A) In the fourth step S4A, the halide AX synthesized in the third step S3A is dissolved in the first solution to prepare a second solution.

[0042] The halide AX may be dissolved in the first solution by adding a solution prepared by dissolving the halide AX in a solvent in advance to the first solution and mixing the solution. Examples of the solvent include water, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and γ-butyrolactone. Dimethylformamide is particularly preferred as the solvent.

[0043] When dissolving the halide AX in the first solution, it is preferable to heat the first solution as needed. The heating temperature of the first solution is, for example, 30°C to 100°C. The heating temperature is equal to or lower than the boiling point of the solvent. By keeping the temperature in the range of 60°C to 80°C, the solubility of the raw material BX and the halide AX can be further increased.

[0044] The concentration of the raw material BX in the second solution is preferably 3% by mass to 30% by mass. By setting the concentration of the raw material BX in the second solution to 3% by mass to 30% by mass, it is possible to form a precursor thin film suitable for forming the substance 101. The concentration of the raw material BX in the second solution is more preferably 10% by mass or less.

[0045] The concentration of the halide AX in the second solution is preferably 3% by mass to 30% by mass. By setting the concentration of the halide AX in the second solution to 3% by mass to 30% by mass, a thin film of a precursor suitable for forming the substance 101 can be formed. The concentration of the halide AX in the second solution is more preferably 10% by mass or less.

[0046] The molar ratio of the raw material BX to the halide AX in the second solution is preferably 4:1 to 1:2, which makes it easier to obtain the thin film of the present disclosure when the thin film of the precursor is heated.

[0047] (Fifth Step S5A) In the fifth step S5A, the second solution is gradually cooled to change from a dissolved state to a crystallized solid state, thereby precipitating crystals of the compound A. ２ BX ６ The resulting crystals have the formula:

[0048] The slow cooling is preferably carried out under a constant temperature gradient using a known temperature-controllable device. Here, the temperature-lowering treatment under a constant temperature gradient is not particularly limited, as long as it is performed, for example, at an average cooling rate of 5°C / h or less, to change the second solution from a dissolved state to a crystallized solid state and precipitate crystals. For example, the temperature-lowering time for crystal precipitation from the temperature at which the solution is dissolved (specifically, for example, 70°C) to the temperature at which the solution is crystallized solid (specifically, for example, 30°C) can be, for example, 8 to 40 hours. In such cases, the temperature-lowering treatment is preferably carried out under a temperature gradient condition with a constant temperature decrease rate within the range of 1 to 5°C per hour. The average cooling rate is preferably 2 to 4°C / h, more preferably 3°C / h.

[0049] The second solution is gradually cooled to change from a dissolved state to a crystalline solid state, thereby precipitating crystals, thereby obtaining compound A.２ BX ６ By performing the treatment of the fifth step S5A for forming a crystal having the above formula, the obtained crystal becomes a single crystal.

[0050] (Method for manufacturing photovoltaic element) Electrode layers (negative electrode layer 106A, positive electrode layer 107A) are formed on the crystal (single crystal body) obtained through the fifth step S5A using a known film formation method such as vacuum deposition or sputtering, and the positive electrode layer 107A is formed on one side of the thickness direction of the thin film, and the negative electrode layer 106A is formed on the other side, making it possible to manufacture a device including a photovoltaic element. The positive electrode layer 107A or the negative electrode layer 106A may be formed on the above-mentioned substrate. That is, a coating film of the precursor (i.e., the second solution) is formed on the positive electrode layer 107A or the negative electrode layer 106A, and the coating film is slowly cooled to change from a dissolved state to a crystallized solid state and precipitate crystals, thereby forming the compound A. ２ BX ６ Alternatively, an organic-inorganic composite material 100A may be obtained in which crystals having the formula (I) are formed. Alternatively, the single crystal obtained in the fifth step S5A may be dissolved in a solvent to prepare a coating solution, and a coating film may be formed on the positive electrode layer 107A or the negative electrode layer 106A by spin coating or the like. Furthermore, a positive electrode-side adhesive layer and a negative electrode-side adhesive layer may be formed between the organic-inorganic composite material 100A and the positive electrode layer 107A and between the organic-inorganic composite material 100A and the negative electrode layer 106A, respectively, using a film-forming method conforming to a conventional method in the art, such as vacuum deposition, spin coating, or sputtering. The organic-inorganic composite material (thin film) 100A has the same configuration as the organic-inorganic composite material (thin film) 100, but while the organic-inorganic composite material 100 is polycrystalline, the organic-inorganic composite material 100A is single crystalline.

[0051] As described above, in the photovoltaic element 120A including the organic-inorganic composite material (thin film) 100A of this embodiment, the chiral molecules 103 induce chirality in the arrangement of the substance 101. This can increase the bulk photovoltaic generation ability induced or possessed by the organic-inorganic composite material 100A.

[0052] The present invention includes a solar cell equipped with a photovoltaic element 120A including the organic-inorganic composite material 100A of this embodiment. As described above, when the organic-inorganic composite material 100A is irradiated with circularly polarized light or when the light includes circularly polarized light, the organic-inorganic composite material 100A of this embodiment can detect a current resulting from the circularly polarized light absorbed in the pseudo-linear structure of the substance 101, and exhibits a phenomenon in which photovoltaic power is generated by the substance alone (i.e., the bulk photovoltaic effect), and can also be used as a novel photovoltaic material that can efficiently utilize the visible light region.

[0053] As described above, such novel photovoltaic materials generate an electromotive force using a single material, and furthermore, this electromotive force does not depend on the band gap. Therefore, there is no theoretical upper limit to their photoelectric conversion efficiency. Unlike conventional solar cells that generate a potential at a heterointerface where different materials come into contact (for example, a p-n junction interface or an interface between a light absorbing layer and an electron / hole transport layer), this will enable the development of solar cells that do not use such potential difference interfaces, and is expected to reduce the burden on solar cell manufacturing processes and dramatically improve their performance.

[0054] (Method of Manufacturing Organic-Inorganic Composite Material Composed of Thin Film) Next, a method of manufacturing an organic-inorganic composite material composed of a thin film according to the present disclosure will be described. FIG. 4 is a flowchart of the manufacturing method according to the present disclosure. The manufacturing method according to the present disclosure includes: (1) a first step S1 of synthesizing a raw material BX, which is a precursor of a substance 101 having an octahedral structure composed of an ion X and a tetravalent metal ion, which is an ion B; (2) a second step S2 of dissolving the raw material BX in a solvent to prepare a first solution; (3) a third step S3 of synthesizing a halide AX of a chiral molecule 103 composed of an ion X and an ion A; (4) a fourth step S4 of dissolving the halide AX synthesized in the third step S3 in the first solution to prepare a second solution; (5) a fifth step S5 of applying the second solution to a substrate by spin coating to form a coating film composed of a precursor on the substrate; and (6) a fifth step S6 of heating the obtained coating film to convert the substance 101 and the chiral molecule 103 into a compound A composed of three types of ions A, B, and X. ２ BX ６and a sixth step S6 of forming a thin film comprising compound A. ２ BX ６ The ion B in the formula (I) includes only tetravalent metal ions, and the tetravalent metal ion is preferably tellurium.

[0055] (First Step S1) In the first step S1, a raw material BX of a precursor of the substance 101 having an octahedral structure composed of ion X and ion B, which is a tetravalent metal ion, is synthesized. The precursor of the substance 101 refers to a substance at a stage before the substance 101 is produced. The raw material BX of the precursor is, for example, TeCl ４ , TeBr ４ , TeI ４ etc. The raw material BX may be commercially available, or may be synthesized using a synthesis method conforming to a common method in the art. When a commercially available product is used as the raw material BX, the first step S1 can be skipped by the purchaser of the commercially available product, since it is used in the process of producing the commercially available product.

[0056] (Second Step S2) In the second step S2, the raw material BX synthesized in the first step S1 is dissolved in a solvent to prepare a first solution. The solvent is not particularly limited as long as it can dissolve the raw material BX. Examples of the solvent include dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and γ-butyrolactone. Dimethylformamide is particularly preferred as the solvent.

[0057] When dissolving the raw material BX in a solvent, it is advisable to heat the solvent as needed. The heating temperature of the solvent is, for example, 30°C to 100°C. The heating temperature is equal to or lower than the boiling point of the solvent. By keeping the temperature range from 60°C to 80°C, the solubility of the raw material BX can be further increased.

[0058] The concentration of the raw material BX in the first solution is preferably 15% by mass to 40% by mass, and a thin film of a precursor suitable for forming the substance 101 can be formed.

[0059] (Third Step S3) In the third step S3, a halide AX of a chiral molecule 103 composed of an ion X and an ion A is synthesized. Here, the ion X is Cl, Br, or I. The chiral molecule 103, which is the ion A, preferably has a functional group capable of forming a salt with a halogen. Examples of functional groups capable of forming a salt with a halogen include alkylamino groups such as a methylamino group and an ethylamino group, and aminocarboxylic acid groups. Examples of the chiral molecule 103 before halogenation include the aforementioned R-(+)-1-(1-naphthyl)ethylamine, R-(+)-1-(2-naphthyl)ethylamine, S-(-)-1-(1-naphthyl)ethylamine, and S-(-)-1-(1-naphthyl)ethylamine. The halogenated chiral molecule 103 may be commercially available or may be synthesized using a synthesis method based on a conventional method in the art. When a commercially available product is used as the halide AX, the third step S3 is used in the process of producing the commercially available product, and therefore the purchaser of the commercially available product can skip this step.

[0060] (Fourth Step S4) In the fourth step S4, the halide AX synthesized in the third step S3 is dissolved in the first solution to prepare a second solution.

[0061] The halide AX may be dissolved in the first solution by adding a solution prepared by dissolving the halide AX in a solvent in advance to the first solution and mixing the solution. Examples of the solvent include dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and γ-butyrolactone. Dimethylformamide is particularly preferred as the solvent.

[0062] When dissolving the halide AX in the first solution, it is preferable to heat the first solution as needed. The heating temperature of the first solution is, for example, 30°C to 100°C. The heating temperature is equal to or lower than the boiling point of the solvent. By keeping the temperature in the range of 60°C to 80°C, the solubility of the raw material BX can be further increased.

[0063] The concentration of the raw material BX in the second solution is preferably 10% by mass to 50% by mass. By setting the concentration of the raw material BX in the second solution to 10% by mass to 50% by mass, a precursor thin film suitable for forming the substance 101 can be formed. The concentration of the raw material BX in the second solution is more preferably 20% by mass or more. The concentration of the raw material BX in the second solution is more preferably 40% by mass or less.

[0064] The concentration of the halide AX in the second solution is preferably 10% by mass to 50% by mass. By setting the concentration of the halide AX in the second solution to 10% by mass to 40% by mass, a precursor thin film suitable for forming the substance 101 can be formed. The concentration of the halide AX in the second solution is more preferably 20% by mass or less.

[0065] The molar ratio of the raw material BX to the halide AX in the second solution is preferably 4:1 to 1:2, which makes it easier to obtain the thin film of the present disclosure when the thin film of the precursor is heated.

[0066] (Fifth Step S5) In the fifth step S5, the second solution is applied onto a substrate by spin coating to form a coating film made of the precursor on the substrate.

[0067] The spin-coating conditions are not particularly limited and can be set appropriately depending on the desired film quality. For example, a thin film of the precursor may be formed by dropping the second solution onto the substrate and then rotating the substrate at 1,000 rpm to 50,000 rpm. The material of the substrate is not limited. Examples of the substrate include indium tin oxide (ITO), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), and indium zinc oxide (IZO).

[0068] (Sixth Step S6) In the sixth step S6, the precursor coating film obtained in the fifth step S5 is heat-treated to form a compound A consisting of three types of ions A, B, and X. ２ BX ６ That is, in the sixth step S6, the substance 101 and the chiral molecule 103 are heated to form a thin film having the compound A. ２ BX ６ A thin film having the formula:

[0069] Heating may be performed using a known heating device such as a heater. By heating the precursor coating and sublimating the halide AX contained in the precursor coating, a thin film composed of the substance 101 and the chiral molecules 103 distributed therebetween can be obtained. Here, the heating temperature is not particularly limited as long as it can form the organic-inorganic composite material (thin film) 100, but is preferably set in the range of 70°C or more and 120°C or less, for example. The heating time is also not particularly limited as long as it can form the organic-inorganic composite material (thin film) 100, but is preferably set in the range of 15 minutes or more and 60 minutes or less, for example.

[0070] By carrying out the fifth step S5 and the sixth step S6 without crystallizing the second solution (including a state in which the second solution is not completely crystallized), the inorganic chains 102 of the organic-inorganic composite material 100 obtained through the sixth step S6 have a textured structure, and it is possible to effectively and efficiently obtain a polycrystalline body in which the inorganic chains 102 are preferentially oriented in a specific direction rather than randomly. Preferably, the fifth step S5 and the sixth step S6 are carried out without crystallizing the second solution at all.

[0071] A positive electrode layer can be formed on one side of the organic-inorganic composite material 100 obtained through the sixth step S6 using a known film-forming method such as vacuum deposition or sputtering, and a negative electrode layer can be formed on the other side in the thickness direction, thereby obtaining a circular polarization detection element that can output circularly polarized light information as an electrical signal. The positive electrode layer or negative electrode layer may be formed on the above-mentioned substrate. That is, a coating film of a precursor may be formed on the positive electrode layer or negative electrode layer, and the organic-inorganic composite material 100 may be obtained in the same process. Furthermore, a positive electrode-side adhesive layer and a negative electrode-side adhesive layer may be formed between the organic-inorganic composite material 100 and the positive electrode layer and between the organic-inorganic composite material 100 and the negative electrode layer, respectively, using a film-forming method based on a conventional method in the technical field, such as vacuum deposition, spin coating, or sputtering.

[0072] As described above, in the organic-inorganic composite material 100 of this embodiment, the chiral molecules 103 induce chirality in the arrangement of the substance 101. This allows the absorption wavelength range of the organic-inorganic composite material 100 for circularly polarized light to be expanded to the range of 350 nm to 800 nm, preferably to the range of 400 nm to 700 nm.

[0073] Furthermore, the organic-inorganic composite material 100 has high electrical conductivity. Therefore, by connecting electrodes to both ends in the thickness direction, when the light irradiated onto the organic-inorganic composite material 100 is circularly polarized or contains circularly polarized light, it is possible to detect an electric current resulting from the circularly polarized light absorbed by the pseudo-linear chain structure of the substance 101. That is, the inorganic chains 102 formed using only R-configuration chiral molecules or S-configuration chiral molecules can selectively absorb right-handed circularly polarized light or left-handed circularly polarized light, and the resulting electric current can be detected. Furthermore, even when the abundance ratio of either the R-configuration or the S-configuration is higher than the abundance ratio of the other, it is possible to induce an R-configuration or S-configuration chiral structure in the perovskite structure, selectively absorb right-handed circularly polarized light or left-handed circularly polarized light, and the resulting electric current can be detected.

[0074] Furthermore, the organic-inorganic composite material 100 of this embodiment does not require a polarizer or a wave plate to detect circularly polarized light, and therefore has a high extinction ratio, making it possible to directly detect circularly polarized light with high sensitivity and high resolution, which was impossible to directly detect with conventional photodetectors.

[0075] Therefore, the organic-inorganic composite material 100 of this embodiment can be used as a circular polarization detection element, and various devices, such as a polarization camera, can be realized that incorporate the circular polarization detection element. By directly detecting circularly polarized light, information such as the intensity distribution of birefringence can be obtained, which cannot be obtained with linearly polarized light.

[0076] (Wavelength shift method for shifting the circularly polarized light absorption wavelength to a longer wavelength) Next, the wavelength shift method of the present disclosure will be described. The wavelength shift method of the present disclosure is a wavelength shift method for shifting the circularly polarized light absorption wavelength detected by the circular polarization detection element 120 to a longer wavelength, and is a wavelength shift method for shifting the circularly polarized light absorption wavelength detected by the circular polarization detection element 120 to a longer wavelength, the wavelength shift method being a method for shifting the circularly polarized light absorption wavelength detected by the circular polarization detection element 120 to a longer wavelength, the ... ２ BX６ The method includes a step of disposing an organic-inorganic composite material 100, which contains only tetravalent metal ions as ions B contained within the octahedral structure of the organic-inorganic composite material 100, as a light-receiving layer of a circular polarization detection element. By disposing the organic-inorganic composite material 100 as a light-receiving layer of a circular polarization detection element 120, it is possible to shift the circular polarization absorption wavelength of the circular polarization detection element 120 to a longer wavelength side than the circular polarization absorption wavelength of a conventional circular polarization detection element.

[0077] In order to further shift the circularly polarized light absorption wavelength to a longer wavelength side, it is preferable to replace ion B with an ion having a larger electron cloud than the ion before substitution. For example, an ion having a larger electron cloud can be exemplified by tetravalent tellurium. Here, the electron cloud refers to the state of electrons moving around an atomic nucleus, which appears as a cloud surrounding the nucleus from the perspective of quantum mechanical probability. It is expected that a larger electron cloud will make it easier to shift the circularly polarized light absorption wavelength of the organic-inorganic composite material 100 to a longer wavelength side. The electron cloud spread can be confirmed by calculating a probability density function using a known method. Incidentally, by shifting the circularly polarized light absorption wavelength to a longer wavelength side, for example, a circular polarization detection element having a CD signal intensity in the ultraviolet region and a circular polarization detection element having a CD signal intensity in the visible region can be used, resulting in a wide CD signal intensity in the visible region.

[0078] Furthermore, chiral molecules 103 that can narrow the spacing between the substances 101 in the inorganic chain 102 can be used. Examples of such chiral molecules include molecules having functional groups or structures with self-organizing ability, such as alkyl groups or aromatic rings. In this specification, "self-organizing ability" refers to the ability to self-organize and form a specific structure under specific conditions. In the case of chiral molecules having alkyl groups, longer alkyl group chains increase crystallinity, so alkyl groups with six or more carbon atoms are expected to improve the self-organizing ability. Increasing the area of ​​the aromatic rings of the polycyclic aromatic compound, which is the chiral molecule 103, or increasing the number of interacting benzene rings, restricts the arrangement space and makes it easier for the molecules to stack on a plane. Therefore, increasing the number of benzene rings in the chiral molecule 103 enhances the packing effect between the chiral molecules 103. Therefore, it is expected that chiral molecules 103 with three or more benzene rings will improve the packing effect. It is expected that the aromatic ring of the chiral molecule 103 is a fused aromatic ring to improve the above-mentioned packing effect.

[0079] The organic-inorganic composite material, its manufacturing method, circular polarization detection element, wavelength shift method, photovoltaic element, and solar cell of the present disclosure have been described above. Note that the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. In addition, the components in the above-described embodiments can be replaced with known components as appropriate without departing from the spirit of the present invention.

[0080] The effects of the present invention will be made clearer by the following examples. Note that the present invention is not limited to the following examples and can be practiced with appropriate modifications within the scope of the present invention.

[0081] Example 1 Manufacturing Method of Organic-Inorganic Composite Material Consisting of Thin Film (Part 1: Thin Film 1) A thin film was manufactured by carrying out the method for manufacturing a thin film according to the above embodiment in the following procedure. 1 g of S-(-)-1-(1-naphthyl)ethylamine (S-1-NEA) was mixed with 500 μL of hydrogen iodide (HI), and the resulting mixture was stirred at 0°C for 2 hours to obtain S-(+)-1-(1-naphthyl)ethylamine hydroiodide ((S-1-NEA)I). Subsequently, 500 μL of dimethylformamide (DMF) was used as a solvent, and tellurium iodide (TeI) was added to the mixture. ４ A solution containing the raw materials for the thin film was prepared by mixing 1.0 M of ((S-1-NEA)I) and 0.75 M of ((S-1-NEA)I) and stirring the resulting mixture at 70°C for 1 hour. The prepared solution was applied to a separately prepared base substrate, and a coating film of the precursor was formed by spin coating. The formed coating film of the precursor was heated at 100°C for 30 minutes to form a thin film of (S-1-NEA)I. ２ TeI ６ A thin film (thin film 1) of

[0082] The obtained thin film was subjected to XRD analysis etc. as described below to calculate various physical properties of the pseudo-linear structure according to the present invention (see FIG. 1(a)). 1) Physical properties (unit cell parameters) of the pseudo-chain structure according to the present invention (1) a = 13.9781(3) Å (2) b = 7.951980(10) Å (3) c = 15.4902(4) Å (4) α = 90°, β = 92.346(2)°, γ = 90° (5) P2 １ (Chiral Space Group)

[0083] Example 2: Method for producing an organic-inorganic composite material consisting of a thin film (Part 2: Thin film 2) A thin film was produced in the same manner as in Example 1, except that R-(+)-1-(1-naphthyl)ethylamine (R-1-NEA) was used instead of 1 g of S-(-)-1-(1-naphthyl)ethylamine (S-1-NEA). ２ TeI ６ A thin film (thin film 2) of

[0084] The obtained thin film was subjected to XRD analysis etc. as described below to calculate various physical properties of the pseudo-linear structure according to the present invention (see FIG. 1(b)). 1) Physical properties (unit cell parameters) of the pseudo-chain structure according to the present invention (1) a = 13.9856(4) Å (2) b = 7.5155(2) Å (3) c = 15.4763(4) Å (4) α = 90°, β = 92.382(2)°, γ = 90° (5) P2 １ (Chiral Space Group)

[0085] Example 3: Method for producing an organic-inorganic composite material consisting of a crystal (Part 1: Single Crystal 1) The method for producing a crystal according to the above embodiment was carried out in the following procedure to produce a single crystal. 1 g of S-(-)-1-(1-naphthyl)ethylamine (S-1-NEA) was mixed with 500 μL of hydrogen iodide (HI), and the resulting mixture was stirred at 0°C for 2 hours to obtain S-(+)-1-(1-naphthyl)ethylamine hydroiodide ((S-1-NEA)I). Subsequently, 1 mL of water was used as a solvent, and tellurium iodide (TeI) was added to the mixture. ４ A solution containing the raw material for the single crystal was prepared by mixing 158.8 mg (0.25 mmol) of ((S-1-NEA)I) with 2.0 ml of hydrogen iodide (HI, aq, 55%) and mixing the mixture with 149.6 mg (0.50 mmol) of ((S-1-NEA)I). The mixture was stirred at 70°C for 1 hour to prepare a solution containing the raw material for the single crystal. The solution was cooled from 70°C to 30°C under a temperature gradient condition where the temperature was decreased at a rate of 3°C per hour, and black needle-like crystals of (S-1-NEA)I were obtained. ２ TeI ６ A single crystal (Single Crystal 1) of 85.2 atom % was obtained. The single crystal was analyzed for its elemental composition by energy dispersive X-ray fluorescence spectroscopy, and the iodine content was 85.2 atom % and the tellurium content was 14.8 atom %, that is, the abundance ratio of iodine to tellurium was 6:1.

[0086] Example 4: Method for producing a crystalline organic-inorganic composite material (part 2: single crystal 2) A crystal was produced in the same manner as in Example 1, except that R-(+)-1-(1-naphthyl)ethylamine (R-1-NEA) was used instead of S-(-)-1-(1-naphthyl)ethylamine (S-1-NEA) used in Example 3. (R-1-NEA) ２ TeI ６ The single crystal (Single Crystal 2) was obtained. The elemental composition of the obtained single crystal was analyzed by energy dispersive X-ray fluorescence spectroscopy, and the abundance ratio of elemental iodine to elemental tellurium was found to be 6:1, similar to the elemental composition analysis of Example 3.

[0087] (XRD Measurement) For Example 3 (Single Crystal 1) and Example 4 (Single Crystal 2), a RUGAKU XtaLAB Synergy-S X-ray diffractometer with a Mo tube was used. Olex2 software was used for crystal structure analysis. For Example 1 (Thin Film 1) and Example 2 (Thin Film 2), a MiniFlex was used to measure the X-ray diffraction (XRD) pattern of each thin film at room temperature. A CuKα source was used for this measurement. The tube voltage and tube current during measurement were 40 kV and 15 mA, respectively. The measurement conditions were a ω of 1.25° and an accumulation time of 10° / min. The physical properties of the pseudo-linear structure according to the present invention were determined based on the results of XRD measurement.

[0088] FIG. 5 shows the X-ray diffraction spectrum of Example 3 (single crystal body 1). The vertical axis of FIG. 5 represents the diffraction intensity (a.u.), and the horizontal axis of FIG. E represents the diffraction angle 2θ (deg). As shown in FIG. 5, it was confirmed that the octahedral structures do not share any vertices or faces. The X-ray diffraction spectrum shown in FIG. 5 is similar to the X-ray diffraction spectrum shown in FIG. 6 (described later), confirming that Example 1 (thin film 1) and Example 3 (single crystal body 1) have the same structure. FIG. 6 shows the X-ray diffraction spectrum of Example 1 (thin film 1). The vertical axis of FIG. 6 represents the diffraction intensity (a.u.), and the horizontal axis of FIG. 6 represents the diffraction angle 2θ (deg). As shown in FIG. 6, it was confirmed that the octahedral structures do not share any vertices or faces. The X-ray diffraction spectrum shown in FIG. 6 is similar to the X-ray diffraction spectrum shown in FIG. 5, and it was confirmed that Example 1 (thin film 1) and Example 3 (single crystal body 1) have the same structure.

[0089] (Absorption Spectrum Measurement) Measurement was carried out for Examples 1 and 2 using an ultraviolet-visible spectrophotometer (JASCO J-1500) to obtain the absorption spectrum of each thin film.

[0090] (Circular dichroism spectrum measurement) Measurement was performed on Example 1 (thin film 1), Example 2 (thin film 2), Example 3 (single crystal 1), and Example 4 (single crystal 2) using a circular dichroism spectrometer (JASCO J-1500) to obtain circular dichroism spectra of the thin films.

[0091] FIG. 7 shows the absorption spectra and circular dichroism spectra of Example 3 (single crystal 1) and Example 4 (single crystal 2). The upper graph in FIG. 7 shows the absorption spectrum of Example 4 (single crystal 2). The horizontal axis of the upper graph in FIG. 7 represents wavelength (nm), and the vertical axis represents absorbance. The lower graph in FIG. 7 shows the circular dichroism spectra of Example 3 (single crystal 1) and Example 4 (single crystal 2). The vertical axis of the lower graph in FIG. 7 represents CD signal intensity (mdeg), and the horizontal axis of the lower graph in FIG. 7 represents wavelength. As shown in FIG. 7, it was confirmed that a wide CD signal can be obtained in the visible region by using a tetravalent metal ion as ion B. It was also confirmed that an absorption spectrum similar to that shown in the upper graph in FIG. 7 was obtained for Example 3 (single crystal 1) (not shown). FIG. 8 shows the circular dichroism spectra of Example 1 (thin film 1) and Example 2 (thin film 2). The vertical axis of Fig. 8 represents the CD signal intensity (mdeg), and the horizontal axis of Fig. 8 represents the wavelength. As shown in Fig. 8, it was confirmed that a wide CD signal can be obtained in the visible region by using a tetravalent metal ion as ion B.

[0092] (Bulk Photovoltaic Measurement) For Example 3 (Single Crystal 1) and Example 4 (Single Crystal 2), a negative electrode probe 106 was placed at one of two separate positions on the same surface of the obtained thin film (thin film prepared from a single crystal) 100A, and a positive electrode probe 107 was placed at the other (see the device structure in Figure 9), and the thin film was irradiated with light containing circularly polarized light, thereby measuring the current generated between the probes. Based on the obtained measurement results, the presence or absence of a bulk photovoltaic effect possessed by the thin film and the photoelectric conversion characteristics were evaluated.

[0093] Figure 9 shows the photoelectric conversion characteristics of Example 3 (single crystal body 1) and Example 4 (single crystal body 2). The vertical axis of Figure 9 represents I (current) (unit: pA), and the horizontal axis of Figure 9 (single crystal body) represents voltage (unit: V). As shown in Figure 9 (single crystal body), by using a tetravalent metal ion as ion B, a photovoltage exceeding 4 V was detected, confirming the existence of the bulk photovoltaic effect possessed by the single crystal body. Incidentally, since the band gap of a one-dimensional tellurium crystal is approximately 1.8 eV, it can be seen that the above-mentioned bulk photovoltaic effect is manifested by the characteristic structure possessed by the single crystal body.

[0094] The organic-inorganic composite material of the present disclosure induces or has a high circularly polarized light absorption intensity over a wide wavelength range in the visible light region, and therefore has high industrial applicability.

[0095] 100, 100A Thin film, 101 Material, 102 Inorganic chain, 103 Chiral molecule, 104 Boundary, 105 Organic layer, 106, 106A, 107, 107A Electrode / electrode probe

Claims

1. An organic-inorganic composite material for detecting circularly polarized light or generating bulk photovoltage, comprising: a plurality of inorganic chains made of a substance having an octahedral structure and constituting a pseudo-linear structure; and chiral molecules, wherein the chiral molecules are contained in at least a portion of the boundaries between adjacent inorganic chains, and the chiral molecules are either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, the octahedral structure of the substance is oriented in a certain direction, and the substance and the chiral molecules are oriented in a certain direction, and the compound A is composed of three types of ions A, B, and X. ２ BX ６ wherein the ion B and the ion X form a plurality of units each having the octahedral structure, and the octahedral structures of adjacent units do not share any vertex or face, but include a pseudo-linear structure aligned with the orientation of the chiral molecules, and the ion B in the octahedral structure is a tetravalent metal ion.

2. The organic-inorganic hybrid material according to claim 1, wherein the tetravalent metal ion is a tetravalent tellurium ion.

3. The organic-inorganic hybrid material according to claim 1, wherein the ion A is an aromatic compound containing an ethylammonium ion, and the tetravalent metal ion is a tetravalent tellurium ion.

4. The organic-inorganic hybrid material according to claim 3, wherein the aromatic compound is a polycyclic aromatic compound.

5. The organic-inorganic hybrid material according to claim 4, wherein the aromatic ring of the polycyclic aromatic compound is a naphthalene ring or an anthracene ring.

6. A method for producing the organic-inorganic composite material according to claim 1, comprising: a first step of synthesizing raw material BX of the precursor of the substance having an octahedral structure, which is composed of ion X and ion B, which is the tetravalent metal ion; a second step of dissolving raw material BX in a solvent to prepare a first solution; a third step of synthesizing halide AX of the chiral molecule composed of ion X and ion A; a fourth step of dissolving halide AX synthesized in the third step in the first solution to prepare a second solution; a fifth step of applying the second solution onto a substrate by spin coating to form a coating film composed of the precursor on the substrate; and a fifth step of heating the resulting coating film to produce compound A. ２ BX ６ and a sixth step of forming a thin film comprising the compound A. ２ BX ６ wherein the ions B contain only the tetravalent metal ions.

7. A method for producing the organic-inorganic composite material according to claim 1, comprising: a first step of synthesizing raw material BX of the precursor of the substance having the octahedral structure, which is composed of ion X and ion B, which is the tetravalent metal ion; a second step of dissolving the raw material BX in a solvent to prepare a first solution; a third step of synthesizing halide AX of the chiral molecule composed of ion X and ion A; a fourth step of dissolving halide AX synthesized in the third step in the first solution to prepare a second solution; and a fourth step of gradually cooling the second solution to change it from a dissolved state to a crystallized solid state and precipitate crystals, thereby producing compound A. ２ BX ６ and a fifth step of forming a crystal having the compound A. ２ BX ６ wherein the ions B contain only the tetravalent metal ions.

8. The manufacturing method according to claim 6 or 7, wherein the ion A is an aromatic compound containing an ethylammonium ion, and the tetravalent metal ion is a tetravalent tellurium ion.

9. The method according to claim 8, wherein the aromatic compound is a polycyclic aromatic compound.

10. The method according to claim 9, wherein the aromatic ring of the polycyclic aromatic compound is a naphthalene ring or an anthracene ring.

11. A circular polarization detection element comprising the organic-inorganic composite material according to any one of claims 1 to 5.

12. A wavelength shift method for shifting the circularly polarized light absorption wavelength detected by a circularly polarized light detection element to a longer wavelength, comprising: ２ BX ６ the thin film comprises, as a light receiving layer of a circular polarization detection element, a thin film containing only tetravalent metal ions as ions B contained within the octahedral structure of the thin film, the thin film comprising: a plurality of inorganic chains made of a substance having the octahedral structure and constituting a pseudo-linear structure; and chiral molecules, the chiral molecules being contained in at least a portion of the boundaries between adjacent inorganic chains, the chiral molecules being either S-chiral molecules or R-chiral molecules, or the abundance ratio of either is higher than the abundance ratio of the other, the octahedral structure being oriented in a certain direction, and the substance and the chiral molecules being compound A composed of three types of ions A, B, and X. ２ BX ６ wherein the ions B and X form a plurality of units each having the octahedral structure, and the octahedral structures of adjacent units do not share any vertex or face, but include a pseudo-linear structure that follows the orientation of the chiral molecules.

13. A photovoltaic element comprising the organic-inorganic composite material according to any one of claims 1 to 5.

14. A solar cell comprising the photovoltaic element according to claim 13.

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