JPWO2019053967A1 - Photoelectric conversion element manufacturing method and solar cell manufacturing method - Google Patents

Abstract

Provided are a method for manufacturing a photoelectric conversion element capable of suppressing variations in photoelectric conversion efficiency between elements, and a method for manufacturing a solar cell through the manufacturing method. Photoelectric conversion element having a first electrode having a conductive support and a photosensitive layer, a hole transport layer provided in contact with the photosensitive layer, and a second electrode provided on the hole transport layer. The method for producing the above-mentioned method is to apply a coating solution a containing a precursor compound capable of forming a perovskite type crystal structure onto a conductive support to form a coating film a, and Coating a coating liquid b containing a hole transport material on the coating a to form the coating b, and subjecting the laminated structure of the coating a and the coating b to heat treatment to form a perovskite type coating on the coating a. Forming a crystal structure.

Description

  The present invention relates to a method for manufacturing a photoelectric conversion element and a method for manufacturing a solar cell.

  Photoelectric conversion elements are used in various optical sensors, copying machines, solar cells, and the like. Solar cells are being put into practical use as those that utilize non-depleting solar energy. Among these, the dye-sensitized solar cell using an organic dye or Ru bipyridyl complex as a sensitizer has been actively researched and developed, and the photoelectric conversion efficiency has reached about 11%.

  On the other hand, in recent years, research results report that a solar cell using a metal halide as a compound having a perovskite type crystal structure (hereinafter also referred to as “perovskite compound”) can achieve relatively high photoelectric conversion efficiency. Have been attracting attention. The compound having a perovskite type crystal structure can be formed into a film by solution coating, and after the coating, a high temperature heat treatment is performed to form a perovskite type crystal structure. However, this heat treatment may cause pinholes, cracks, voids, etc. in the formed crystal layer. As a technique for avoiding this, Patent Document 1 describes that after applying a precursor solution of a perovskite compound, a low temperature gas is sprayed on the coating film to promote spontaneous formation of a perovskite type crystal structure. There is.

JP, 2017-59643, A

As a structure of a photoelectric conversion element using a perovskite compound as a photosensitive layer, a photosensitive layer is provided on a conductive support to form a first electrode, and a hole transport layer is provided in contact with the photosensitive layer of the first electrode. A form in which a second electrode is provided on the top is known. Based on the practical application of the photoelectric conversion element of this form, the present inventors further studied the performance, and even if the elements were manufactured by the same method, the variation in the photoelectric conversion efficiency between the elements was relatively large. However, it has been found that it is difficult to stably supply an element with a small variation in performance.
Therefore, the present invention provides a method of manufacturing a photoelectric conversion element having the above-mentioned layer structure, which can effectively reduce variations in photoelectric conversion efficiency between elements, and a method of manufacturing a solar cell through the manufacturing method. The challenge is to provide a method.

The present inventors have conducted extensive studies in view of the above problems. As a result, a first electrode provided with a photosensitive layer containing a perovskite compound on a conductive support, a hole transport layer provided in contact with the photosensitive layer of the first electrode, and a second electrode further thereon. It was found that the above-mentioned problems can be solved by performing the steps of forming the photosensitive layer and the hole-transporting layer integrally instead of independently in manufacturing the photoelectric conversion element having the layer structure.
That is, the coating film a formed by applying the coating liquid containing the compound (precursor) necessary for forming the perovskite type crystal structure is not subjected to heat treatment (that is, without promoting the formation of the perovskite type crystal structure). The coating liquid containing the hole transport material is applied onto the coating film a to form the coating film b. At this stage, the laminated structure of the coating film a and the coating film b is first subjected to heat treatment to form the coating film a. By forming a perovskite type crystal structure in the inside, it is possible to effectively suppress the variation in photoelectric conversion efficiency between elements of the obtained element and improve the stability of the performance of the produced photoelectric conversion element. I found it.
The present invention has been completed through further studies based on these findings.

That is, the above problems of the present invention have been solved by the following means.
[1]
Photoelectric conversion device having a first electrode having a conductive support and a photosensitive layer, a hole transport layer provided in contact with the photosensitive layer, and a second electrode provided on the hole transport layer. The manufacturing method of
Forming a coating film a by applying a coating liquid a containing a precursor compound capable of forming a perovskite type crystal structure on a conductive support;
Forming a coating film b by applying a coating liquid b containing a hole transport material on the coating film a without subjecting the coating film a to heat treatment;
And subjecting the formed laminated structure of the coating film a and the coating film b to a heat treatment to form a perovskite type crystal structure in the coating film a.
[2]
The method for manufacturing a photoelectric conversion element according to [1], wherein the hole transport material contains a compound represented by the following formula (H1).
_{^{A 1 - (L 1) nb}} - (D 1) na - (L 2) nc -A 2 Formula (H1)
In the formula, A ¹ and A ² represent a heterocyclic group, a hydrocarbon ring group or an acceptor group.
L ¹ and L ² represent a linking group, and nb and nc are integers of 0-5.
D ¹ represents a condensed ring structure, and na is an integer of 1 to 4.
[3]
Said ^{D 1} is represented by the following formula ^(D 1 -1) or ^(D 1 -2), [2] a method for manufacturing a photoelectric conversion element according.

X ^{1 to} X ⁴ represent a sulfur atom, an oxygen atom or a selenium atom.
Z ^{1 to} Z ⁴ represent a nitrogen atom or CR ^a , and R ^a represents a hydrogen atom or a substituent.
A and B show a ring structure.
* Indicates a connection site.
[4]
The method for producing a photoelectric conversion element according to [1], wherein the hole transport material contains a compound represented by the following formula (H2-1) or (H2-2).
_{^{D 2 - (L 3) nd}} -C (R 1) = A 3 Equation (H2-1)
_{^{D 2 = (L 3) nd}} -C (R 1) = A 3 Equation (H2-2)
In the formula, D ² represents a donor group.
L ³ represents a linking group, and nd represents an integer of 0 to 5.
R ¹ represents a hydrogen atom or a substituent.
A ³ represents an acceptor group.
[5]
The method for producing a photoelectric conversion element according to [4], wherein the D ² includes a condensed ring structure composed of 3 or more rings.
[6]
[4] or [5] in which the compound represented by the above formula (H2-1) is represented by the following formula (H2-1-1), (H2-1-2) or (H2-1-3). ] The manufacturing method of the photoelectric conversion element of description.

In the formula, E represents a ring structure.
G represents a heterocyclic structure containing a nitrogen atom as a ring-constituting atom.
R < ² > -R < ⁴ > shows a substituent, ne is an integer of 0-4, nf is an integer of 0-3, nh is an integer of 0-5, and ng is 0 or 1.
L ³ and A ³ have the same meanings as L ³ and A ^{3 in} formula (H2-1), respectively.
[7]
The method for manufacturing a photoelectric conversion element according to [1], wherein the hole transport material contains a compound represented by the following formula 1-1 or 1-2.

In the formula, X ^{1 to} X ⁴ represent an oxygen atom, a sulfur atom, a group represented by the following formula 1-a, a group represented by the following formula 1-b, or = C (G ¹ ) (G ² ). . G ¹ and G ² represent an electron-withdrawing group and are not linked to each other to form a ring.
Y ^{1 to} Y ⁴ represent OR, SR, O ⁻ , S ⁻ , a halogen atom, a group represented by the following formula 1-c, or a group represented by the following 1-d. R represents a hydrogen atom or a substituent.

In the formula, A ¹ represents a hydrocarbon ring or a hetero ring, and B ¹ represents a hetero ring or NR ^N1 R ^N2 . R ^N1 and R ^N2 represent a substituent, and they are not linked to each other to form a ring.
L ^{1 to} L ⁴ represent a linking group. na and nd are integers of 0 to 2, and nb and nc are 1 or 2.
* Indicates a linking site with the above formula 1-1 or formula 1-2.
However, the compound represented by the formula 1-1 and the compound represented by the formula 1-2 have at least one group represented by any one of the formulas 1-a to 1-d, It does not have a COOH and -NH _2.
[8]
The method for manufacturing a photoelectric conversion element according to [7], wherein the hole transport material is represented by any one of the following formulas 2-1 to 2-5.

In the formula, A ² represents a heterocycle. A ⁴ represents a heterocycle in which two or more rings are condensed or an oxygen atom. A ³ , A ⁵ , B ² and B ³ represent a heterocycle.
L ^{5 to} L ¹³ represent a linking group. ne to ng, ni and nj are integers of 0 to 2, and nh and nk to nm are 1 or 2.
X ^{6 to} X ¹¹ represent an oxygen atom, a sulfur atom or = C (G ¹ ) (G ² ). G ¹ and G ² represent an electron-withdrawing group and are not linked to each other to form a ring.
Y ^{5 to} Y ⁸ represent OR, SR, O ⁻ , S ⁻ or a halogen atom.
R ^{1 to} R ⁸ represent a substituent.
[9]
The method for producing a photoelectric conversion element according to any one of [1] to [8], wherein the solution containing the hole transport material does not contain a dopant.
[10]
A method for manufacturing a solar cell, wherein a photoelectric conversion element is obtained by the method for manufacturing a photoelectric conversion element according to any one of [1] to [9], and a solar cell is manufactured using the obtained photoelectric conversion element.

  In this specification, a part of the notation of each formula may be expressed as a rational formula in order to understand the chemical structure of the compound. Along with this, in each formula, the partial structure is referred to as a (substituted) group, ion or atom, etc., but in the present specification, these are represented by the above formula in addition to the (substituted) group, ion or atom, etc. It may mean an element group or an element that constitutes a (substituted) group or an ion.

  In the present specification, the expression of a compound (including a complex and a dye) is used to mean the compound itself, a salt thereof, and an ion thereof. In addition, a compound that does not specify substitution or non-substitution is meant to include a compound having any substituent as long as the intended effect is not impaired. This also applies to the substituent, the linking group and the like (hereinafter referred to as the substituent and the like).

In the present specification, when there are a plurality of substituents and the like represented by a specific code, or when a plurality of substituents and the like are defined at the same time, each substituent and the like are the same or different from each other, unless otherwise specified. May be. The same applies to the definition of the number of substituents and the like. In addition, when a plurality of substituents and the like are close to each other (particularly when they are adjacent to each other), they may be linked to each other to form a ring, unless otherwise specified. Further, a ring, for example, an aliphatic ring, an aromatic ring, or a hetero ring may be further condensed to form a condensed ring.
In this specification, when defining the carbon number of a group, this carbon number means the carbon number of the entire group. That is, when the group has a substituent, it means the total number of carbon atoms including the substituent.
In the present specification, the same reference numeral may be used between different general formulas as a reference numeral indicating a substituent or the like of the general formula, but unless otherwise specified, the same reference numeral is used between different general formulas. The groups represented by are mutually independent groups. That is, the symbols in the general formula are defined for each general formula.

In the present specification, the numerical range represented by using "to" means a range including the numerical values before and after "to" as the lower limit value and the upper limit value.
In the present invention, the term "provided on a layer" means not only a form provided directly on the surface of the "-layer" but also a form provided with another layer on the surface of the "-layer" and provided via this "other layer". It is meant to include. In addition, the upper and lower expressions in the layer structure of the photoelectric conversion element are such that the conductive support side is the bottom and the second electrode side is the top.

  According to the method for manufacturing a photoelectric conversion element of the present invention, a photosensitive layer containing a perovskite compound is provided on a conductive support, a hole transport layer is provided in contact with the photosensitive layer, and a second electrode is further provided thereon. It is possible to effectively reduce variations in photoelectric conversion efficiency between elements in a photoelectric conversion element having a layered structure including. Further, according to the method for manufacturing a solar cell of the present invention, it is possible to reduce the variation in photoelectric conversion efficiency between elements of the photoelectric conversion element that constitutes the solar cell, and as a result, effectively reduce the variation in photoelectric conversion efficiency between solar cells. Can be reduced to

FIG. 1 is a sectional view schematically showing a preferable embodiment of the photoelectric conversion element of the present invention, including an enlarged view of a circular portion in a layer. FIG. 2 is a sectional view schematically showing a preferred embodiment having a thick photosensitive layer of the photoelectric conversion element of the present invention. FIG. 3 is a sectional view schematically showing another preferable embodiment of the photoelectric conversion element of the present invention. FIG. 4 is a sectional view schematically showing another preferable embodiment of the photoelectric conversion element of the present invention.

[Configuration of photoelectric conversion element]
The configuration of the photoelectric conversion element (hereinafter, also referred to as “the photoelectric conversion element of the present invention”) obtained by the method for manufacturing the photoelectric conversion element of the present invention (hereinafter, also simply referred to as the “production method of the present invention”) will be described. The photoelectric conversion element of the present invention is provided with a first electrode in the form of a photosensitive layer provided on a conductive support, a hole transport layer provided on the photosensitive layer, and a hole transport layer. And a second electrode.
The photosensitive layer contains a light absorber having a specific organic cation, a metal cation, and an anion, and at least a part of the light absorber has a perovskite type crystal structure. When the light absorber has a portion that does not have a perovskite crystal structure, the cation and anion can be in an ionic bond state in the portion that does not have a perovskite crystal structure.

  In the present invention, having a photosensitive layer on a conductive support or forming a photosensitive layer on a conductive support means that the photosensitive layer is provided in contact with the surface of the conductive support (directly provided), and It is meant to include a mode in which the photosensitive layer is provided above the surface of the conductive support through another layer.

In the embodiment having a photosensitive layer above the surface of the conductive support via another layer, the other layer provided between the conductive support and the photosensitive layer does not deteriorate the cell performance of the solar cell. There is no particular limitation as long as it exists. For example, a porous layer, a blocking layer, an electron transport layer, a hole transport layer, etc. are mentioned.
In the present invention, as an embodiment in which the photosensitive layer is provided above the surface of the conductive support through another layer, for example, the photosensitive layer is a thin film (see FIG. 1) or a thick film on the surface of the porous layer. (See FIG. 2), a mode of providing a thin film or a thick film on the surface of the blocking layer (see FIG. 3), and a mode of providing a thin film or a thick film on the surface of the electron transport layer (see FIG. 4). ). The photosensitive layer may be provided linearly or dispersedly, but is preferably provided as a film.

  In the photoelectric conversion element of the present invention, the photosensitive layer contains a light absorber having a specific organic cation, a metal cation, and an anion, and at least a part of the light absorber is composed of a perovskite compound.

  The photoelectric conversion element of the present invention is not particularly limited in configuration other than the configuration specified in the present invention, and known configurations relating to the photoelectric conversion element and the solar cell can be adopted. Each layer constituting the photoelectric conversion element of the present invention is designed according to the purpose, and may be formed in, for example, a single layer or multiple layers.

Hereinafter, preferred embodiments of the photoelectric conversion element obtained by the production method of the present invention will be described.
1-4, the same code | symbol means the same component (member).
1 and 2, the size of the fine particles forming the porous layer 12 is emphasized. These fine particles are preferably blocked (deposited or adhered) in the horizontal direction and the vertical direction with respect to the conductive support 11 to form a porous structure.

  In the present specification, simply referring to the photoelectric conversion element 10 means the photoelectric conversion elements 10A to 10D unless otherwise specified. The same applies to the system 100 and the first electrode 1. Further, when simply referred to as the photosensitive layer 13, it means the photosensitive layers 13A to 13C unless otherwise specified. Similarly, the hole transport layer 3 means the hole transport layers 3A and 3B unless otherwise specified.

As a preferable embodiment of the photoelectric conversion element obtained by the manufacturing method of the present invention, for example, the photoelectric conversion element 10A shown in FIG. 1 can be mentioned. The system 100A shown in FIG. 1 is a system in which the photoelectric conversion element 10A is applied to a battery for causing the operating means M (for example, an electric motor) to work in the external circuit 6.
This photoelectric conversion element 10A has a first electrode 1A, a second electrode 2, and a hole transport layer 3A between the first electrode 1A and the second electrode 2.
The first electrode 1A includes a conductive support 11 composed of a support 11a and a transparent electrode 11b, a porous layer 12, and a porous layer 12 as shown in an enlarged sectional area a in which the sectional area a is enlarged in FIG. The surface of the material layer 12 has a photosensitive layer 13A provided with a light absorber containing a perovskite compound. Further, the blocking layer 14 is provided on the transparent electrode 11b, and the porous layer 12 is formed on the blocking layer 14. As described above, in the photoelectric conversion element 10A having the porous layer 12, the surface area of the photosensitive layer 13A is increased, and thus it is estimated that the charge separation and charge transfer efficiency are improved.

  The photoelectric conversion element 10B shown in FIG. 2 schematically shows an aspect in which the photosensitive layer 13A of the photoelectric conversion element 10A shown in FIG. 1 is provided thickly. In this photoelectric conversion element 10B, the hole transport layer 3B is provided thinly. The photoelectric conversion element 10B is different from the photoelectric conversion element 10A shown in FIG. 1 in the film thickness of the photosensitive layer 13B and the hole transport layer 3B, but is the same as the photoelectric conversion element 10A except for these points. ing.

  The photoelectric conversion element 10C shown in FIG. 3 schematically shows another preferable embodiment of the photoelectric conversion element obtained by the manufacturing method of the present invention. The photoelectric conversion element 10C is different from the photoelectric conversion element 10B shown in FIG. 2 in that the porous layer 12 is not provided, but is the same as the photoelectric conversion element 10B except for this point. That is, in the photoelectric conversion element 10C, the photosensitive layer 13C is formed as a thick film on the surface of the blocking layer 14. In the photoelectric conversion element 10C, the hole transport layer 3B can be formed thick similarly to the hole transport layer 3A.

  The photoelectric conversion element 10D shown in FIG. 4 schematically shows another preferable embodiment of the photoelectric conversion element obtained by the manufacturing method of the present invention. This photoelectric conversion element 10D is different from the photoelectric conversion element 10C shown in FIG. 3 in that an electron transport layer 15 is provided instead of the blocking layer 14, but other than this point, it is configured similarly to the photoelectric conversion element 10C. There is. The first electrode 1D has a conductive support 11, and an electron transport layer 15 and a photosensitive layer 13C which are sequentially formed on the conductive support 11. This photoelectric conversion element 10D is preferable in that each layer can be formed of an organic material. Thereby, the productivity of the photoelectric conversion element is improved, and the photoelectric conversion element can be thinned or made flexible.

In the present invention, the system 100 to which the photoelectric conversion element 10 is applied functions as a solar cell as follows.
That is, in the photoelectric conversion element 10, the light that has passed through the conductive support 11 or the second electrode 2 and entered the photosensitive layer 13 excites the light absorber. The excited light absorber has a high-energy electron and can emit this electron. The light absorber that has emitted high-energy electrons becomes an oxidant (cation).

In the photoelectric conversion elements 10A to 10D, the electrons emitted from the light absorbing agent move between the light absorbing agents and reach the conductive support 11. The electrons that have reached the conductive support 11 work in the external circuit 6, and then return to the photosensitive layer 13 via the second electrode 2 and the hole transport layer 3. The light absorber is reduced by the electrons returned to the photosensitive layer 13.
In the photoelectric conversion element 10, the system 100 functions as a solar cell by repeating such a cycle of excitation of the light absorber and electron transfer.

In the photoelectric conversion elements 10A to 10D, the way electrons flow from the photosensitive layer 13 to the conductive support 11 depends on the presence or absence of the porous layer 12, its type, and the like. In the photoelectric conversion element 10 of the present invention, electron conduction occurs in which electrons move between the light absorbers. Therefore, in the present invention, when the porous layer 12 is provided, the porous layer 12 can be formed of an insulator other than the conventional semiconductor. When the porous layer 12 is formed of a semiconductor, electron conduction occurs in which electrons move inside the semiconductor particles of the porous layer 12 or between the semiconductor particles. On the other hand, when the porous layer 12 is made of an insulator, electron conduction does not occur in the porous layer 12. When the porous layer 12 is formed of an insulator, a relatively high electromotive force (Voc) can be obtained by using aluminum oxide (Al ₂ O ₃ ) fine particles as the insulating fine particles.
Even when the blocking layer 14 as the other layer is formed of a conductor or a semiconductor, electron conduction occurs in the blocking layer 14.
Further, electron conduction also occurs in the electron transport layer 15.

In the present invention, the material and each member used for the photoelectric conversion element can be prepared by a conventional method except for the light absorber. Regarding the photoelectric conversion element or the solar cell using the perovskite compound, for example, see J. Am. Chem. Soc. , 2009, 131 (17), p. 6050-6051 and Science, 338, p. 643 (2012) can be referred to.
Further, the materials and each member used for the dye-sensitized solar cell can be referred to. Regarding the dye-sensitized solar cell, for example, JP 2001-291534 A, U.S. Pat. No. 4,927,721, U.S. Pat. No. 4,684,537, U.S. Pat. No. 5,0843,65. Specification, US Pat. No. 5,350,644, US Pat. No. 5,463,057, US Pat. No. 5,525,440, JP-A-7-249790, JP2004. Reference can be made to JP-A-220974 and JP-A-2008-135197.

  Hereinafter, preferred embodiments of members and compounds included in the photoelectric conversion element of the present invention will be described.

<First electrode 1>
The first electrode 1 has a conductive support 11 and a photosensitive layer 13, and functions as a working electrode in the photoelectric conversion element 10.
The first electrode 1 preferably further includes at least one layer of a porous layer 12, a blocking layer 14, and an electron transport layer 15, as shown in FIGS. 1 to 4.
The first electrode 1 preferably has at least the blocking layer 14 from the viewpoint of short circuit prevention, and more preferably has the porous layer 12 and the blocking layer 14 from the viewpoint of light absorption efficiency and short circuit prevention.
In addition, the first electrode 1 preferably has the electron transport layer 15 formed of an organic material from the viewpoint of improving the productivity of the photoelectric conversion element and making it thinner or flexible.

-Conductive support 11-
The conductive support 11 is not particularly limited as long as it has conductivity and can support the photosensitive layer 13 and the like. The conductive support 11 is composed of a material having conductivity, for example, a metal, or a glass or plastic support 11a, and a transparent electrode 11b as a conductive film formed on the surface of the support 11a. A configuration having is preferable.

Among them, as shown in FIGS. 1 to 4, a conductive support 11 in which a transparent metal 11b is formed by coating a conductive metal oxide on the surface of a glass or plastic support 11a is more preferable. . Examples of the support 11a made of plastic include the transparent polymer film described in paragraph No. 0153 of JP 2001-291534 A. As a material for forming the support 11a, in addition to glass and plastic, ceramic (JP-A-2005-135902) and conductive resin (JP-A-2001-160425) can be used. As the metal oxide, tin oxide (TO) is preferable, and fluorine-doped tin oxide such as indium-tin oxide (tin-doped indium oxide; ITO) and fluorine-doped tin oxide (FTO) is particularly preferable. At this time, the coating amount of the metal oxide is preferably 0.1 to 100 g per 1 m ² of the surface area of the support 11a. When the conductive support 11 is used, it is preferable that light be incident from the support 11a side.

The conductive support 11 is preferably substantially transparent. In the present invention, "substantially transparent" means that the transmittance of light (wavelength 300 to 1200 nm) is 10% or more, preferably 50% or more, particularly preferably 80% or more.
The thickness of the support 11a and the conductive support 11 is not particularly limited and is set to an appropriate thickness. For example, the thickness is preferably 0.01 μm to 10 mm, more preferably 0.1 μm to 5 mm, and particularly preferably 0.3 μm to 4 mm.
When the transparent electrode 11b is provided, the film thickness of the transparent electrode 11b is not particularly limited and is, for example, preferably 0.01 to 30 μm, more preferably 0.02 to 25 μm, and further preferably 0.025 to 20 μm. Is particularly preferable.

  The conductive support 11 or the support 11a may have a light management function on the surface. For example, the surface of the conductive support 11 or the support 11a may have an antireflection film, which is described in JP-A-2003-123859, in which a high refractive film and a low refractive index oxide film are alternately laminated. Well, it may have a light guide function described in JP-A-2002-260746.

-Blocking layer 14-
In the present invention, like the photoelectric conversion elements 10A to 10C, preferably on the surface of the transparent electrode 11b, that is, the conductive support 11, the porous layer 12, the photosensitive layer 13, the hole transport layer 3, and the like. In between, a blocking layer 14 is provided.
In the photoelectric conversion element, for example, when the photosensitive layer 13 or the hole transport layer 3 is electrically connected to the transparent electrode 11b or the like, a reverse current is generated. The blocking layer 14 functions to prevent this reverse current. The blocking layer 14 is also referred to as a short circuit prevention layer.
The blocking layer 14 can also function as a scaffold carrying a light absorber.
The blocking layer 14 may be provided even when the photoelectric conversion element has an electron transport layer. For example, in the case of the photoelectric conversion element 10D, it may be provided between the conductive support 11 and the electron transport layer 15.

The material for forming the blocking layer 14 is not particularly limited as long as it is a material that can perform the above functions, and is a substance that transmits visible light and is an insulating substance for the conductive support 11 (transparent electrode 11b) and the like. Is preferred. The “insulating substance for the conductive support 11 (transparent electrode 11b)” is specifically a material having an energy level in the conduction band that forms the conductive support 11 (metal oxide that forms the transparent electrode 11b). Compound) which is higher than the energy level of the conduction band of the material) and lower than the energy level of the conduction band of the material forming the porous layer 12 or the energy level of the ground state of the light absorber (n-type semiconductor compound).
Examples of the material forming the blocking layer 14 include silicon oxide, magnesium oxide, aluminum oxide, calcium carbonate, cesium carbonate, polyvinyl alcohol, polyurethane and the like. Further, a material generally used as a photoelectric conversion material may be used, and examples thereof include titanium oxide, tin oxide, zinc oxide, niobium oxide, and tungsten oxide. Of these, titanium oxide, tin oxide, magnesium oxide, aluminum oxide and the like are preferable.
The thickness of the blocking layer 14 is preferably 0.001 to 10 μm, more preferably 0.005 to 1 μm, and particularly preferably 0.01 to 0.1 μm.

  In the present invention, the film thickness of each layer can be measured by observing the cross section of the photoelectric conversion element 10 using a scanning electron microscope (SEM) or the like.

-Porous layer 12-
In the present invention, like the photoelectric conversion elements 10A and 10B, the porous layer 12 is preferably provided on the transparent electrode 11b. When the blocking layer 14 is provided, the porous layer 12 is preferably formed on the blocking layer 14.
The porous layer 12 is a layer that functions as a scaffold that carries the photosensitive layer 13 on its surface. In the solar cell, in order to increase the light absorption efficiency, it is preferable to increase the surface area of at least a portion that receives light such as sunlight, and it is preferable to increase the surface area of the porous layer 12 as a whole.

The porous layer 12 is preferably a fine particle layer having fine pores, in which fine particles of the material forming the porous layer 12 are deposited or adhered. The porous layer 12 may be a fine particle layer formed by depositing two or more kinds of fine particles. When the porous layer 12 is a fine particle layer having pores, the amount of the light absorber carried (adsorption amount) can be increased.
In order to increase the surface area of the porous layer 12, it is preferable to increase the surface area of the individual fine particles forming the porous layer 12. In the present invention, in the state where the fine particles forming the porous layer 12 are coated on the conductive support 11 or the like, the surface area of the fine particles is preferably 10 times or more, and 100 times or more of the projected area. Is more preferable. This upper limit is not particularly limited and is usually about 5000 times. The particle diameter of the fine particles forming the porous layer 12 is preferably 0.001 to 1 μm as primary particles in the average particle diameter using the diameter when the projected area is converted into a circle. When the porous layer 12 is formed using a dispersion of fine particles, the average particle diameter of the fine particles is preferably 0.01 to 100 μm as the average particle diameter of the dispersion.

The material forming the porous layer 12 is not particularly limited in terms of conductivity, and may be an insulator (insulating material), a conductive material or a semiconductor (semi-conductive material). ..
As a material for forming the porous layer 12, for example, a metal chalcogenide (for example, an oxide, a sulfide, a selenide, or the like), a compound having a perovskite type crystal structure (excluding a perovskite compound used as a light absorber), and silicon. (For example, silicon dioxide, zeolite), or carbon nanotubes (including carbon nanowires and carbon nanorods) can be used.

  The metal chalcogenide is not particularly limited, and preferably titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, aluminum or tantalum oxide, and cadmium sulfide. , Cadmium selenide and the like. Examples of the crystal structure of the metal chalcogenide include anatase type, brookite type and rutile type, and anatase type and brookite type are preferable.

  The compound having a perovskite crystal structure is not particularly limited, and examples thereof include transition metal oxides. For example, strontium titanate, calcium titanate, barium titanate, lead titanate, barium zirconate, barium stannate, lead zirconate, strontium zirconate, strontium tantalate, potassium niobate, bismuth ferrate, strontium barium titanate. , Barium lanthanum titanate, calcium titanate, sodium titanate, and bismuth titanate. Of these, strontium titanate and calcium titanate are preferable.

  The carbon nanotube has a shape in which a carbon film (graphene sheet) is rolled into a tubular shape. Carbon nanotubes are single-walled carbon nanotubes (SWCNT) in which one graphene sheet is wound in a cylindrical shape, two-walled carbon nanotubes in which two graphene sheets are concentrically wound (DWCNT), and multiple graphene sheets are concentric circles. It is classified as a multi-walled carbon nanotube (MWCNT) that is wound into a shape. Any carbon nanotube can be used as the porous layer 12 without any particular limitation.

  Among them, the material forming the porous layer 12 is preferably an oxide of titanium, tin, zinc, zirconium, aluminum or silicon, or a carbon nanotube, and more preferably titanium oxide or aluminum oxide.

  The porous layer 12 may be formed of at least one of the above-mentioned metal chalcogenide, compound having a perovskite type crystal structure, silicon oxide and carbon nanotube, and may be formed of a plurality of types. .

  The thickness of the porous layer 12 is not particularly limited and is usually in the range of 0.05 to 100 μm, preferably 0.1 to 100 μm. When used as a solar cell, the thickness is preferably 0.1 to 50 μm, more preferably 0.2 to 30 μm.

-Electron transport layer 15-
In the present invention, it is also preferable to have the electron transport layer 15 on the surface of the transparent electrode 11b like the photoelectric conversion element 10D.
The electron transport layer 15 has a function of transporting electrons generated in the photosensitive layer 13 to the conductive support 11. The electron transport layer 15 is formed of an electron transport material capable of exhibiting this function. The electron transport material is not particularly limited, and an organic material (organic electron transport material) is preferable. Examples of the organic electron-transporting material include fullerene compounds such as [6,6] -Phenyl-C61-Butyric Acid Methyl Ester (PC ₆₁ BM), perylene compounds such as perylene tetracarboxydiimide (PTCDI), and tetracyanoquinodimethane. A low molecular weight compound such as (TCNQ) or a high molecular weight compound may be used.
The film thickness of the electron transport layer 15 is not particularly limited and is preferably 0.001 to 10 μm, more preferably 0.01 to 1 μm.

-Photosensitive layer (light absorbing layer) 13-
The photosensitive layer 13 is preferably the surface of each layer of the porous layer 12 (photoelectric conversion elements 10A and 10B), the blocking layer 14 (photoelectric conversion element 10C), or the electron transport layer 15 (photoelectric conversion element 10D) (photosensitive layer). 13 includes the inner surface of the recess when the surface provided with 13 is uneven.).
In the present invention, the photosensitive layer 13 contains a light absorber. This light absorber contains an organic cation, a cation of a metal atom, and an anion. At least a part of this light absorber has a perovskite type crystal structure.
Further, the photosensitive layer may have a light absorbing component such as a metal complex dye or an organic dye in addition to the above light absorbing agent.

  The mode in which the photosensitive layer 13 is provided on the conductive support 11 is as described above. The photosensitive layer 13 is preferably provided on the surface of each layer so that excited electrons flow to the conductive support 11 or the second electrode 2. At this time, the photosensitive layer 13 may be provided on the entire surface of each layer, or may be provided on a part of the surface.

The film thickness of the photosensitive layer 13 is appropriately set according to the mode in which the photosensitive layer 13 is provided on the conductive support 11, and is not particularly limited. Usually, the film thickness is, for example, preferably 0.001 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 5 μm.
When the porous layer 12 is provided, the total film thickness together with the film thickness of the porous layer 12 is preferably 0.01 μm or more, more preferably 0.05 μm or more, further preferably 0.1 μm or more, and 0.3 μm or more. Particularly preferred. The total film thickness is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 30 μm or less. The total film thickness can be within a range in which the above values are appropriately combined. Here, as shown in FIG. 1, when the photosensitive layer 13 is a thin film, the film thickness of the photosensitive layer 13 is from the interface with the porous layer 12 along the direction perpendicular to the surface of the porous layer 12. , The distance to the interface with the hole transport layer 3.
When the photoelectric conversion element 10 has the porous layer 12, the total film thickness of the porous layer 12, the photosensitive layer 13, and the hole transport layer 3 is not particularly limited, and is preferably 0.01 μm or more, 0.05 μm or more is more preferable, 0.1 μm or more is further preferable, and 0.3 μm or more is particularly preferable. The total film thickness is preferably 200 μm or less, more preferably 50 μm or less, further preferably 30 μm or less, and particularly preferably 5 μm or less. The total film thickness can be within a range in which the above values are appropriately combined.
In the present invention, when the photosensitive layer is provided in the form of a thick film (photosensitive layers 13B and 13C), the light absorber contained in this photosensitive layer may function as a hole transport material.

[Light absorber]
In the photoelectric conversion element of the present invention, the light absorber constituting the photosensitive layer has an organic cation, a cation of a metal atom, and an anion of an anionic atom or an anionic atomic group, and at least a part of the light absorber. Has a perovskite type crystal structure.

As the organic cation constituting the light absorber, one or more organic cations represented by the following formula (I) can be used.
Formula _{^{(I) R 1 -NR 1a 3}} +
In formula (I), R ¹ is more preferably an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aliphatic heterocyclic group or a group represented by the following formula (Ia), and alkyl A group or a group represented by the following formula (Ia) is more preferable, and methyl, ethyl or a group represented by the following formula (Ia) is particularly preferable.

In the group represented by the formula (Ia), X ^a represents NR ^2c , an oxygen atom or a sulfur atom, and NR ^2c is preferable. Here, R ^2c represents a hydrogen atom or a substituent. The substituent that can be used as R ^2c is not particularly limited, and an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, or an aliphatic heterocyclic group is preferable. R ^2c is preferably a hydrogen atom.

R ^2b represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be used as R ^2b is not particularly limited, and examples thereof include an amino group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, and an aliphatic heterocyclic group.

The alkyl group that can be used as R ^2b and R ^2c includes a linear alkyl group and a branched alkyl group. 1-18 are preferable, as for carbon number of this alkyl group, 1-12 are more preferable, 1-6 are more preferable, and 1-3 are especially preferable. Preferable specific examples of the alkyl group include, for example, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, pentyl, hexyl, decyl and octadecyl.

The cycloalkyl group that can be used as R ^2b and R ^2c preferably has 3 to 8 carbon atoms. Specific examples of preferable cycloalkyl groups include cyclopropyl, cyclopentyl, and cyclohexyl.

The alkenyl group that can be used as R ^2b and R ^2c includes a straight chain alkenyl group and a branched alkenyl group. The carbon number of this alkenyl group is preferably 2 to 18, more preferably 2 to 7, and further preferably 2 to 5. Preferred specific examples of the alkenyl group include, for example, vinyl, allyl, butenyl, pentenyl and hexenyl.

The alkynyl group that can be used as R ^2b and R ^2c includes a linear alkynyl group and a branched alkynyl group. The carbon number of the alkynyl group is preferably 2-18, more preferably 2-7, and even more preferably 2-5. Preferred specific examples of the alkynyl group include, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl and octynyl.

The aryl group that can be used as R ^2b and R ^2c preferably has 6 to 14 carbon atoms. Specific examples of preferable aryl groups include phenyl and naphthyl, with phenyl being more preferable.

The heteroaryl group that can be used as R ^2b and R ^2c is a monocyclic group consisting only of an aromatic heterocycle and another ring (for example, an aromatic ring, an aliphatic ring or a heterocycle) fused to the aromatic heterocycle. And a group consisting of the fused heterocycle.
As the ring-constituting heteroatom constituting the aromatic heterocycle, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The number of ring members of the aromatic heterocycle is preferably a 3- to 8-membered ring, more preferably a 5-membered ring or a 6-membered ring.
Examples of the 5-membered aromatic heterocycle include a pyrrole ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a triazole ring, a furan ring, and a thiophene ring. Examples of the condensed heterocycle containing a 5-membered aromatic heterocycle include a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, an indoline ring, and an indazole ring.
Further, examples of the 6-membered aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. Further, examples of the condensed heterocycle containing a 6-membered aromatic heterocycle include a quinoline ring and a quinazoline ring.

The aliphatic heterocyclic group that can be used as R ^2b and R ^2c is a monocyclic group consisting of only an aliphatic heterocycle and an aliphatic condensed ring in which another ring (for example, an aliphatic ring) is condensed with the aliphatic heterocycle. And a group consisting of a heterocycle. As the ring-constituting hetero atom constituting the aliphatic heterocycle, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. Further, the number of ring members of the aliphatic heterocycle is preferably a 3- to 8-membered ring, and more preferably a 5-membered ring or a 6-membered ring. The aliphatic heterocycle has preferably 0 to 24 carbon atoms, more preferably 1 to 18 carbon atoms, further preferably 2 to 10 carbon atoms, and particularly preferably 3 to 5 carbon atoms.
Preferred specific examples of the aliphatic heterocycle include a pyrrolidine ring, an oxolane ring, a thiolane ring, a piperidine ring, a tetrahydrofuran ring, an oxane ring (tetrahydropyran ring), a thiane ring, a piperazine ring, a morpholine ring, a quinuclidine ring, a pyrrolidine ring, and azetidine ring. Examples thereof include a ring, an oxetane ring, an aziridine ring, a dioxane ring, a pentamethylene sulfide ring and γ-butyrolactone.

Preferred forms of an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group and an aliphatic heterocyclic group that can be used as R ¹ are, respectively, an alkyl group that can be used as R ^2b , a cycloalkyl group, It is the same as the preferable form of the alkenyl group, alkynyl group, aryl group, heteroaryl group and aliphatic heterocyclic group.

Examples of the group represented by the formula (Ia) include a (thio) acyl group, a (thio) carbamoyl group, an imidoyl group and an amidino group.
The (thio) acyl group includes an acyl group and a thioacyl group. Acyl group, the total carbon number preferably an acyl group having 1 to 7, for example, formyl, acetyl _{(CH 3 C (= O)} -), propionyl, hexanoyl and the like. Thioacyl group, the total carbon number of preferably thioacyl group having 1 to 7, for example, thioformyl, thioacetyl _{(CH 3 C (= S)} -), thiopropionyl, and the like.
(Thio) carbamoyl group, a carbamoyl group _{(H 2 NC (= O)} -) and thiocarbamoyl group _{(H 2 NC (= S)} -) embraces.
The imidoyl group is a group represented by R ^2b -C (= NR ^2c )-, and R ^2b and R ^2c are each preferably a hydrogen atom or an alkyl group, and this alkyl group is an alkyl group which can be used as R ^1a described above. Is synonymous with. As the imidoyl group for example, formimidoyl (HC (= NH) -) , acetimidoyl _{(CH 3 C (= NH)} -), propionic imidoyl _{(CH 3 CH 2 C (=} NH) -) and the like include To be Among them, formimidoyl is preferable.
Amidino group as the group represented by formula (Ia), ^{R 2c R 2b} of the imidoyl group at the amino group has the structure _{(-C (= NH) NH 2} ) is a hydrogen atom.

  *** represents a binding site to the nitrogen atom in formula (I).

In formula (I), R ^1a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or an aliphatic heterocyclic group.
Preferred forms of an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group and an aliphatic heterocyclic group which can be adopted as R ^1a are, respectively, an alkyl group which can be adopted as R ^2b , a cycloalkyl group, It is the same as the preferable form of the alkenyl group, alkynyl group, aryl group, heteroaryl group and aliphatic heterocyclic group. Two adjacent R ^1a 's linked to a nitrogen atom may be linked to each other to form a ring. In this case, the ring formed may have a hetero atom as a ring-constituting atom.
R ^1a is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom.

In the formula (I), when all three R ^1a are hydrogen atoms, the compound represented by the formula (I) is an organic ammonium compound in which R ¹ and NH ₃ in the above formula (I) are bonded to each other. The structure has cations. When the organic ammonium cation can have a resonance structure, it contains a cation having a resonance structure in addition to the organic ammonium cation. For example, when ^{X a} in group represented by the above formula (Ia) is NH ^{(R 2c} is a hydrogen atom), the structure of the portion represented by ^R 1 ^{-NR 1a} ₃ of the formula (I) is an organic ammonium cation In addition to the structure, the structure of the organic amidinium cation, which is one of the resonance structures of the organic ammonium cation, can be adopted. Examples of the organic amidinium cation include cations represented by the following formula (A ^am ). In the present specification, a form of a resonance structure such as a cation represented by the following formula (A ^am ) is also included in the group represented by the above formula (Ia).

In the perovskite compound constituting the light absorber, the cation of the metal atom is preferably a cation of a metal atom other than the Group 1 element of the periodic table. Examples of the metal atom include calcium (Ca), strontium (Sr), cadmium (Cd), copper (Cu), nickel (Ni), manganese (Mn), iron (Fe), cobalt (Co), palladium (Pd). ), Germanium (Ge), tin (Sn), lead (Pb), ytterbium (Yb), europium (Eu), indium (In), titanium (Ti), bismuth (Bi), thallium (Tl), and other metal atoms. Is mentioned. Among them, Pb atom, Cu atom, Ge atom or Sn atom is particularly preferable.
The cation of the metal atom may be one kind of cation or two or more kinds of cation. In the case of two or more kinds of cations, their ratio (content ratio) is not particularly limited.

In the perovskite compound used in the present invention, the anion represents an anion of an anionic atom or an atomic group. The anion is preferably an anion of a halogen atom or an anion of each atomic group of NCS ⁻ , NCO ⁻ , OH ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ or HCOO ⁻ . Of these, an anion of a halogen atom is more preferable. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The anion may be an anion of one kind of anionic atom or atomic group, or may be an anion of two or more kinds of anionic atoms or atomic groups. When the anion is one kind of anionic atom or atomic group, the anion of iodine atom is preferable. On the other hand, when it is an anion of two or more kinds of anionic atoms or atomic groups, anions of two kinds of halogen atoms, particularly anions of chlorine atom and anions of iodine atom are preferable. The ratio (content ratio) of two or more anions is not particularly limited.

  In the photoelectric conversion device of the present invention, the perovskite compound that constitutes at least a part of the light absorber is represented by, for example, the following formula (i).

Formula (i) A _a M _m X _x
In the formula, A represents a cationic organic group. M represents a metal atom. X represents an anionic atom or an anionic atomic group.
a represents 1 or 2, m represents 1, and a, m and x satisfy a + 2m = x.
In the formula (i), the cationic organic group A exists as the organic cation in the perovskite type crystal structure.
The metal atom M is a metal atom existing as a cation of the above metal atom in the perovskite type crystal structure.
The anionic atom or the anionic atomic group X exists as an anion described above in the perovskite type crystal structure.

A perovskite compound represented by the formula (i) is a perovskite compound represented by the following formula (i-1) when a is 1, and a perovskite compound represented by the following formula (i-2) when a is 2. It is a perovskite compound represented.
Formula (i-1) AMX ₃
Formula (i-2) A ₂ MX ₄

The crystal structure of the perovskite compound may further contain a cation of a Group 1 element of the periodic table.
The cation of the Group 1 element of the periodic table is not particularly limited, and examples thereof include cations (Li ⁺ , Na ⁺ , of each element of lithium (Li), sodium (Na), potassium (K) or cesium (Cs), K ⁺ , Cs ⁺ ) are mentioned, and a cesium cation (Cs ⁺ ) is particularly preferable.

Although details will be described later, the perovskite compound can be generally synthesized from a compound represented by the following formula (ii) and a compound represented by the following formula (iii).
Formula (ii) AX
Formula (iii) MX ₂
In formulas (ii) and (iii), A, M and X have the same meanings as A, M and X in formula (i), respectively.
For the synthesis method of the perovskite compound, for example, Akihiro Kojima, Kenjiro Teshima, Yasuo Shirai, and Tsutomu Miyashiraz cit. Am. Chem. Soc. , 2009, 131 (17), p. 6050-6051 is mentioned. In the present specification, the term “perovskite compound” is used to include all crystal structures that can be formed using AX of the above formula (ii) and MX ₂ of the above formula (iii).

The amount of the light absorber used may be an amount that covers at least a part of the surface of the first electrode 1, and an amount that covers the entire surface is preferable.
The content of the light absorber in the photosensitive layer 13 is usually 1 to 100% by mass.

<Hole transport layer 3>
The photoelectric conversion element of the present invention has the hole transport layer 3 between the first electrode 1 and the second electrode 2 like the photoelectric conversion elements 10A to 10D. In this aspect, it is preferable that the hole transport layer 3 is in contact (lamination) with the photosensitive layer 3C. The hole transport layer 3 is preferably provided between the photosensitive layer 13 of the first electrode 1 and the second electrode 2.
The hole transport layer 3 has a function of supplementing electrons to the oxidant of the light absorber, and is preferably a solid layer (solid hole transport layer).

The hole transport material forming the hole transport layer 3 may be a liquid material or a solid material, and is not particularly limited. Examples thereof include inorganic materials such as CuI and CuNCS, and organic hole transporting materials described in paragraph numbers 0209 to 0212 of JP 2001-291534 A. The organic hole transport material is preferably a conductive polymer such as polythiophene, polyaniline, polypyrrole and polysilane, a spiro compound in which two rings share a central atom having a tetrahedral structure such as C and Si, and a triarylamine. And aromatic amine compounds, triphenylene compounds, nitrogen-containing heterocyclic compounds or liquid crystalline cyano compounds.
The hole transporting material is preferably an organic hole transporting material that can be applied by a solution and becomes solid, and specifically, 2,2 ′, 7,7′-tetrakis- (N, N-di-p-methoxyphenyl). Amino) -9,9'-spirobifluorene (also referred to as spiro-MeOTAD, which is compound S1 described later), poly (3-hexylthiophene-2,5-diyl), 4- (diethylamino) benzaldehyde diphenylhydrazone, Examples thereof include polyethylenedioxythiophene (PEDOT).

  The hole transport layer 3 also preferably contains a compound represented by the following formula (H1) as a hole transport material.

_{^{A 1 - (L 1) nb}} - (D 1) na - (L 2) nc -A 2 Formula (H1)

In formula (H1), A ¹ and A ² represent a heterocyclic group, a hydrocarbon ring group or an acceptor group.
Examples of the heterocyclic group that can be used as A ¹ and A ² include a heteroaryl group and an aliphatic heterocyclic group.
The heteroaryl group that can be used as A ¹ and A ² is a group composed of an aromatic heterocycle, and a condensed heterocycle condensed with another ring (for example, an aromatic ring, an aliphatic ring or a heterocycle). A group consisting of a heterocycle can be mentioned.
The ring-constituting hetero atom of the aromatic hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. Moreover, 3-8 are preferable and, as for the number of ring members of the said aromatic heterocycle, 5 or 6 is more preferable. 0-24 are preferable, as for carbon number of an aromatic heterocycle, 1-18 are more preferable, and 2-12 are more preferable.
Examples of the 5-membered aromatic heterocycle or the condensed heterocycle containing the 5-membered aromatic heterocycle include, for example, a pyrrole ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a selenazole ring, and a triazole ring. , A furan ring, a thiophene ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, an indoline ring or an indazole ring.
Examples of the 6-membered aromatic heterocycle or the condensed heterocycle containing the 6-membered aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a quinoline ring and a quinazoline ring. Can be mentioned.

Examples of the aliphatic heterocyclic group that can be used as A ¹ and A ² include a group composed of an aliphatic heterocycle and an aliphatic condensed heterocycle in which another ring (for example, an aliphatic ring) is condensed with the aliphatic heterocycle. And a group consisting of
The ring-constituting heteroatom of the aliphatic heterocycle is preferably a nitrogen atom, an oxygen atom or a sulfur atom. The number of ring members in the aliphatic heterocycle is preferably 3 to 8, and more preferably 5 or 6. 1-24 are preferable, as for carbon number of an aliphatic heterocycle, 1-18 are more preferable, and 1-12 are more preferable.
Specific preferred examples of the aliphatic heterocycle include a pyrrolidine ring, oxolane ring, thiolane ring, piperidine ring, tetrahydrofuran ring, oxane ring, thian ring, piperazine ring, morpholine ring, quinuclidine ring, pyrrolidine ring, azetidine ring, oxetane ring. , Aziridine ring, dioxane ring, pentamethylene sulfide ring, γ-butyrolactone and the like.

Examples of the hydrocarbon ring group that can be used as A ¹ and A ² include a cycloalkyl group, a cycloalkenyl group, and an aryl group.
The cycloalkyl group that can be used as A ¹ and A ² preferably has 3 to 8 carbon atoms. Specific preferred examples of the cycloalkyl group include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group.
The cycloalkenyl group that can be used as A ¹ and A ² preferably has 3 to 8 carbon atoms. Specific preferred examples of the cycloalkenyl group include a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, and a cyclohexadienyl group.
The aryl group that can be used as A ¹ and A ² preferably has 6 to 14 carbon atoms. Preferable specific examples of the aryl group include, for example, a phenyl group, a naphthyl group and an anthracenyl group, and among them, phenyl is preferable.

In the heterocyclic group and the hydrocarbon ring group which can be used as A ¹ and A ² , at least one —CH ₂ — constituting the ring is —C (═O) —, —C (═S) —, —C ( It may be replaced by any one selected from = NR ^o )-and -C (= CR ^p R ^q )-.
Here, R ^o represents a hydrogen atom or a substituent. R ^p and R ^q represent a hydrogen atom or a substituent, or are bonded to each other to form a ring.
There is no particular limitation on the substituent that can be used as R ^o , R ^p and R ^q , and examples thereof include the substituents that the hydrocarbon ring and the heterocycle as A ¹ and A ² may have, which will be described later. Preferable examples of the substituent that can be adopted as R ^o , R ^p and R ^q include an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group and a cyano group.

The heterocyclic ring and hydrocarbon ring that can be used as A ¹ and A ² may be in a form having a substituent.
This substituent is not particularly limited and is, for example, an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, more preferably 2 to 18 carbon atoms, and further preferably 4 to 18 carbon atoms. For example, methyl, ethyl or propyl. , Isopropyl, butyl, tert-butyl, pentyl, hexyl and decyl, and a cycloalkyl group (preferably a cycloalkyl group having 3 to 8 carbon atoms. Examples thereof include cyclopropyl, cyclopentyl and cyclohexyl. ), An alkenyl group (preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 6 carbon atoms. Examples thereof include vinyl, allyl, butenyl and hexenyl), an alkynyl group (preferably having 2 carbon atoms). To 18, more preferably an alkynyl group having 2 to 4 carbon atoms, for example, ethynyl. Butynyl and hexynyl are included.), An alkoxy group (preferably having a carbon number of 1 to 30, more preferably a carbon number of 2 to 18, and further preferably a carbon number of 4 to 18.) For example, methoxy, ethoxy, isopropyl. Oxy, t-butyloxy, octyloxy, and benzyloxy are included.), An aryloxy group (preferably an aryloxy group having 6 to 14 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably phenoxy). ), An alkylthio group (preferably an alkylthio group having 1 to 30 carbon atoms, and more preferably an alkylthio group having 4 to 18 carbon atoms. Examples thereof include methylthio, ethylthio, isopropylthio, t-butylthio, and octylthio), and an amino group. (Preferably an amino group having 0 to 20 carbon atoms, for example, Examples thereof include alkylamino group, alkenylamino group, alkynylamino group, cycloalkylamino group, cycloalkenylamino group, arylamino group and heterocyclic amino group, more specifically, for example, amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, N-allylamino, N- (2-propynyl) amino, N-cyclohexylamino, N-cyclohexenylamino, anilino, pyridylamino, imidazolylamino, benzimidazolylamino, thiazolylamino, benzothiazoli Ruamino and triazinylamino), an acyl group (preferably an acyl group having 1 to 20 carbon atoms, such as acetyl, cyclohexylcarbonyl and benzoyl), an acyloxy group (preferably having carbon atoms). 1 To 20 acyloxy groups. Examples include acetyloxy, cyclohexylcarbonyloxy and benzoyloxy. ), An alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms. Examples thereof include methoxycarbonyl, ethoxycarbonyl and 2-ethylhexyloxycarbonyl), an aryloxycarbonyl group (preferably having 6 to 10 carbon atoms). 20 aryloxycarbonyl groups, such as phenyloxycarbonyl and naphthyloxycarbonyl, and carbamoyl groups (preferably C1-20 carbamoyl groups. For example, alkylcarbamoyl groups and cycloalkylcarbamoyl groups. Or an arylcarbamoyl group, more specifically, for example, N, N-dimethylcarbamoyl, N-cyclohexylcarbamoyl, or N-phenylcarbamoyl), and an acylamino group. Preferred is an acylamino group having 1 to 20 carbon atoms, such as acetylamino, cyclohexylcarbonylamino and benzoylamino, and a sulfonyl group (preferably a sulfonyl group having 1 to 20 carbon atoms. For example, alkylsulfonyl. Group or an arylsulfonyl group, more specifically, for example, methylsulfonyl, ethylsulfonyl, cyclohexylsulfonyl and benzenesulfonyl can be mentioned.), An aryl group (preferably having 6 to 14 carbon atoms, more preferably having carbon atoms). 6 to 12 aryl groups such as phenyl and naphthyl, heteroaryl groups (groups consisting of an aromatic heterocycle, and aromatic heterocycles containing other rings (eg, aromatic rings, aliphatic rings). And a heterocyclic ring) fused condensed ring To free. The preferred form is the same as the preferred form of the heteroaryl group which may take as A ¹ and A ^2.), Silyl group (preferably a silyl group having 1 to 20 carbon atoms. Alkyl, aryl, alkoxy, and Aryloxy-substituted silyl groups are preferred, such as trimethylsilyl, triethylsilyl, triisopropylsilyl, triphenylsilyl, diethylbenzylsilyl and dimethylphenylsilyl, halogen atoms (fluorine atom, chlorine atom, bromine atom and Examples thereof include an iodine atom, preferably a fluorine atom), a group having a halogen atom, a cyano group and a nitro group. Of these, an alkoxycarbonyl group, a halogen atom or a cyano group is preferable. These substituents may further have a substituent.

The heterocyclic group and hydrocarbon ring group that can be used as A ¹ and A ² also preferably have an electron-withdrawing group as a substituent.
Examples of the electron-withdrawing group include a group having a positive σp value in Hammet's rule, preferably a hydroxycarbonyl group (carboxylic acid), an aryloxycarbonyl group, an alkoxycarbonyl group, a halogen atom, a halogen atom. And a cyano group. Of these, an alkoxycarbonyl group or a cyano group is preferable.

Specific examples of the hydrocarbon ring and the heterocycle represented by A ¹ and A ² include the following structures. In the formula, the wavy line indicates the connecting site with L ¹ , L ² , or D ^{1 in} formula (H1).

Next, the acceptor group that can be used as A ¹ and A ² will be described. As used herein, the term “acceptor property” refers to a relative electronic relationship between at least two types of groups present in one molecule of a compound. Specifically, an acceptor has a relatively high electron accepting property. On the other hand, one having a relatively high electron donating property is called a donor property.
The acceptor group which can be adopted as A ¹ and A ² is a group having a group having a positive σp value in Hammet's rule, and / or having a -M effect in the mesomeric effect, -C (= O)-,- C (= S) - and -C (= NR ^x) - it is a group containing at least one of. Here, R ^X represents a hydrogen atom or a substituent. This substituent is not particularly limited, and examples thereof include the above-mentioned substituents that may be possessed by the heterocyclic ring and aromatic hydrocarbon ring that can be used as A ¹ and A ² . This substituent is preferably an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a cyano group.
Note that the acceptor group which can be taken as A ¹ and A ^2, shall not be included in the heterocyclic group and the hydrocarbon ring group which may take as A ¹ and A ² described above.

The acceptor group that can be used as A ¹ and A ² is preferably a group represented by any of the following formulas (A-1), (A-2) and (A-3). In the compound represented by the formula (H1), at least one of A ¹ and A ² is a group represented by any of the following formulas (A-1), (A-2) and (A-3). Is preferred.

In formula (A-1), Y ^A1 represents an oxygen atom, a sulfur atom or NR ^c , and R ^c represents a hydrogen atom or a substituent. When R ^c is a substituent, examples thereof include the substituents that the above-mentioned hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have, and the preferred forms are also the same. Of these, the substituent that can be used as R ^c is preferably an alkyl group. Y ^A1 is preferably an oxygen atom.
R ^A1 represents a hydrogen atom or a substituent. When R ^A1 is a substituent, examples thereof include the substituents that the hydrocarbon ring or heterocycle that can be used as A ¹ and A ² may have, and the preferred forms are also the same. Of these, the substituent that can be used as R ^A1 is preferably an alkyl group or an alkoxy group.
* Indicates a linking site with L ¹ , L ² or D ¹ .

In formula (A-2), R ^A2 and R ^A3 represent a hydrogen atom or a substituent. However, at least one of R ^A2 and R ^A3 is an electron-withdrawing group.
When R ^A2 and R ^A3 are substituents, there may be mentioned the substituents which the above-mentioned hydrocarbon ring or heterocycle that may be used as A ¹ and A ² may have, and the preferred forms are also the same. However, at least one of R ^A2 and R ^A3 is an electron-withdrawing group, and R ^A2 and R ^A3 are preferably electron-withdrawing groups.
Examples of the electron-withdrawing group that can be adopted as R ^A2 and R ^A3 include groups having a positive σp value in the Hammett's rule. Preferred examples of the electron-withdrawing group include a hydroxycarbonyl group (carboxylic acid), an aryloxycarbonyl group, an alkoxycarbonyl group, a halogen atom, a group having a halogen atom, and a cyano group. Among them, an alkoxycarbonyl group is preferable. Alternatively, a cyano group is preferable.
R ^A4 represents a hydrogen atom or a substituent. When R ^A4 is a substituent, examples thereof include the substituents that the above-mentioned hydrocarbon ring or heterocycle that can be used as A ¹ and A ² may have, and the preferred forms are also the same. R ^A4 is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.
* Represents a linking site with L ¹ , L ² , or D ¹ .

In formula (A-3), X is a hydrocarbon ring or a heterocycle. Provided that at least one _-CH 2 constituting the ring - is, -C (= O) -, - C (= S) -, - C (= NR d) -, and -C ⁽⁼ CR ^{e R} f) It may be replaced by any group selected from-. Here, R ^d represents a hydrogen atom or a substituent. Further, R ^e and R ^f represent a hydrogen atom or a substituent, or are bonded to each other to form a ring. Examples of the substituent that can be used as R ^d , R ^e, and R ^f include the substituents that the hydrocarbon ring and the heterocycle that can be used as A ¹ and A ² may have. preferable.
Examples of the hydrocarbon ring that can be used as X include a cycloalkyl group, a cycloalkenyl group, an aryl group, and the like. The preferred forms of these cycloalkyl groups, cycloalkenyl groups and aryl groups are the same as the preferred forms when the hydrocarbon ring that can be used as A ¹ and A ² is a cycloalkyl group, cycloalkenyl group or aryl group. is there.
Examples of the heterocyclic ring that can be used as X include a heteroaryl group and an aliphatic heterocyclic group. Examples of the heteroaryl group and the aliphatic heterocyclic group include the examples of the heteroaryl group and the aliphatic heterocyclic group that can be used as A ¹ and A ² described above. In one embodiment of the present invention, the heterocycle represented by X preferably contains 1 to 6 heteroatoms selected from oxygen atom, sulfur atom and nitrogen atom, and more preferably 1 to 5 heteroatoms. It is more preferable to include 1 or 2.
The hydrocarbon ring or heterocyclic ring which can be adopted as X has 1 to 4 —CH ₂ — constituting the ring, —C (═O) —, —C (═S) —, and —C (═NR ^d ). More preferably, it is replaced by any one selected from-, -C (= CR ^e R ^f )-, and replaced by any selected from -C (= O)-and -C (= S)-. More preferably. R ^d , R ^e, and R ^f have the same meanings as R ^d , R ^e, and R ^f described above, respectively.
The hydrocarbon ring or heterocycle that can be used as X may have a substituent, and this substituent may be, for example, the hydrocarbon ring or heterocycle that can be used as A ¹ and A ² described above. Good substituents may be mentioned. When the hydrocarbon ring or heterocycle as X has a substituent, the number thereof is, for example, preferably 1 to 7, more preferably 1 to 5, and preferably 1 to 3. Is more preferable.
R ^A5 represents a hydrogen atom or a substituent. When R ^A5 is a substituent, ^examples thereof include a substituent that a hydrocarbon ring and a heterocycle that may be used as A ¹ and A ² may have. R ^A5 is preferably a hydrogen atom or an alkyl group.
* Represents a linking site with L ¹ , L ² , or D ¹ .

In one aspect of the present invention, the group represented by the formula (A-2) is preferably a group represented by the following formula (A-4). The group represented by the formula (A-3) is preferably a group represented by the following formula (A-5). At least one of A ¹ and A ² is preferably a group represented by the following formula (A-4) or (A-5), and more preferably at least one of A ¹ and A ² is a group represented by the following formula (A It is preferably represented by -5). More preferably, A ¹ and A ² are groups represented by the following formula (A-5).

In formula (A-4), EWG represents an electron-withdrawing group. This electron-withdrawing group is the same as the electron-withdrawing group described in formula (A-2). * Indicates a linking site with L ¹ , L ² or D ¹ .

In formula (A-5), X ^A is a sulfur atom, an oxygen atom, or a heterocycle containing NR ^m, and at least one —CH ₂ — constituting the ring is —C (═O) —, —C. A heterocycle which is replaced by any of (= S)-,-(= NR ^d )-, and -C (= CR ^e R ^f )-. R ^m represents a hydrogen atom or a substituent. The substituent is not particularly limited, and examples thereof include the substituents that the hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have. R ^d , R ^e, and R ^f have the same meanings as R ^d , R ^e, and R ^f described above, respectively.
In one embodiment of the present invention, in the heterocycle as X ^A , at least 1 to 4 —CH ₂ — constituting the ring are —C (═O) —, —C (═S) —, —C ( It is more preferable that they are replaced by any one of ═NR ^d ) − and —C (═CR ^e R ^f ) −, and any one selected from —C (═O) — and —C (= S) —. It is even more preferable that they are replaced by
X ^A is preferably a 3- to 8-membered ring, and more preferably a 5- or 6-membered ring. The heterocycle as X ^A is preferably a heterocycle containing 1 to 6 heteroatoms selected from a sulfur atom, an oxygen atom and NR ^m, and more preferably a heterocycle containing 1 to 5 heteroatoms. More preferably, it is a heterocycle containing 1 to 2.

X ^A is also preferably a heterocycle having a substituent, and examples of this substituent include the substituents which the above-mentioned hydrocarbon ring and heterocycle as A ¹ and A ² may have. You can When X ^A is a heterocycle having a substituent, the number of substituents is preferably 1-5, more preferably 1-3.

  The group represented by the above formula (A-5) is more preferably represented by the following formula.

In the above formula, Y ^A2 represents CR ²⁶ R ²⁷ , NR ²⁸ , a sulfur atom or an oxygen atom. R ²⁶ , R ²⁷ and R ²⁸ represent a hydrogen atom or a substituent. The substituent is not particularly limited, and examples thereof include the substituents that the above-mentioned hydrocarbon ring and heterocycle that can be adopted by A ¹ and A ² may have. In one form, Y ^A2 is preferably a sulfur atom or an oxygen atom.

X ^A1 represents a sulfur atom, an oxygen atom, NR ²⁹ or CR ³⁰ R ³¹ . Here, R ²⁹ , R ³⁰ and R ³¹ represent a hydrogen atom or a substituent. This substituent is not particularly limited, and examples thereof include the substituents that the hydrocarbon ring and heterocycle that can be adopted as A ¹ and A ² may have.
Further, -N by two adjacent ^{X A1 = N -, - N} = CR 32 -, or ^-CR 33 = ^{CR 34} - may constitute a. R ³² , R ³³ and R ³⁴ represent a hydrogen atom or a substituent. This substituent is not particularly limited, and examples thereof include the substituents that the hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have.

  Specific examples of the groups represented by the formulas (A-1) to (A-5) include the following structures. In the following specific examples, “*” represents a linking position with the rest of the compound of the present invention, “Me” represents a methyl group, “Et” represents an ethyl group, “Bu” represents a butyl group, "Ph" represents a phenyl group.

D ¹ represents a condensed ring structure, and na is an integer of 1 to 4. D ¹ is a fused ring structure represented by the following formula ^(D 1 -1) or ^(D 1 -2) is preferred. D ¹ is preferably a donor group.

In each of the above formulas, X ^{1 to} X ⁴ represent a sulfur atom, an oxygen atom or a selenium atom. In the formula ^(D 1 -1), it is preferable that at least one of ^{X 1} and ^{X 2} is a sulfur atom, more preferably ^{X 1} and ^{X 2} is a sulfur atom. Further, in the equation ^(D 1 -2), it is preferable that at least one of ^{X 3} and ^{X 4} is a sulfur atom, more preferably ^{X 3} and ^{X 4} is a sulfur atom.

Z ^{1 to} Z ⁴ represent a nitrogen atom or CR ^a , and R ^a represents a hydrogen atom or a substituent. When R ^a is a substituent, examples thereof include the substituents that the hydrocarbon ring or heterocycle that can be used as A ¹ and A ² may have, and among them, an alkyl group is preferable. In the formula ^(D 1 -1), it is preferable that at least one of ^{Z 1} and ^{Z 2} is a nitrogen atom, and more preferably ^{Z 1} and ^{Z 2} is a nitrogen atom. Further, in the equation ^(D 1 -2), it is preferable that at least one of ^{Z 3} and ^{Z 4} is a nitrogen atom, and more preferably ^{Z 3} and ^{Z 4} is a nitrogen atom.

A and B show a ring structure. This ring structure may be a single ring or a condensed ring. In the case of a monocycle, a 5-membered ring or a 6-membered ring is preferable. In the case of a condensed ring, a ring formed by condensing a 5-membered ring and / or a 6-membered ring is preferable. In one aspect of the present invention, rings A and B are preferably condensed rings in which 5 or less rings are fused, or a single ring. More preferably, rings A and B are fused rings in which 3 or less rings are fused, or are monocycles. More preferably, rings A and B are condensed rings in which two rings are condensed, or are monocyclic rings, and monocyclic rings are particularly preferable.
Specific examples of the rings A and B are shown below, but the present invention is not limited thereto. In the following example, "*" ^{is, X 1, X 2, Z} 1 and ^{Z 2} in the formula ^(D 1 -1), or, ^X 3 in the formula ^{(D 1 -2), X 4} , Z 3 and represents a linking position with Z ^4, "Me" represents a methyl group. The following specific examples may further have a substituent.

In one embodiment of the present invention, D ¹ in the formula (H1) is any ^one of the following formulas (D ¹ -3), (D ¹ -4), (D ¹ -5), and (D ¹ -6). It is preferably a group represented.

In each formula, X ^D1 and X ^D2 represent an oxygen atom, a sulfur atom or a selenium atom.
Z ^D1 and Z ^D2 represent a nitrogen atom or CR ^a . R ^a represents a hydrogen atom or a substituent.
R ^D1 represents a hydrogen atom or a substituent.
nd1 is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
* Indicates a linking site with L ¹ , L ² , A ¹ , A ² or D ¹ .
X ^D3 represents an oxygen atom, a sulfur atom, a selenium atom, CR ^g R ^h , NR ⁱ or SiR ^j R ^k , and R ^g , R ^h , R ⁱ , R ^j and R ^k represent a hydrogen atom or a substituent. . X ^D3 is preferably a sulfur atom, CR ^g R ^h or NR ⁱ .
Substituents that R ^a , R ^D1 , R ^g , R ^h , R ⁱ , R ^j, and R ^k can have include the hydrocarbon rings and heterocycles that can be used as A ¹ and A ² described above. Another example is a substituent.

L ¹ and L ² represent a linking group. As the linking group, an alkenylene group, a cycloalkenylene group, an alkynylene group, an arylene group, or a heteroarylene group is preferable, and an alkenylene group, an arylene group, or a heteroarylene group is more preferable.

The alkenylene group that can be used as L ¹ and L ² preferably has 2 to 30 carbon atoms. For example, ethenylene, 1-propenylene, 2-butenylene, 1-butenylene, 3-methyl-2-pentenylene, hexenylene, decenylene and the like can be mentioned. In alkenylene, cis-trans isomerism is not particularly limited.
The cycloalkenylene group that can be used as L ¹ and L ² preferably has 5 to 25 carbon atoms. For example, cyclopentenylene, cyclohexenylene, cyclohexadienylene, cyclooctenylene, cyclooctadienylene and the like can be mentioned.
The alkynylene that can be used as L ¹ and L ² preferably has 2 to 6 carbon atoms. For example, ethynylene may be mentioned.
The arylene group that can be used as L ¹ and L ² is preferably, for example, an arylene group having 6 to 14 carbon atoms. Specific examples include a phenylene group, a naphthylene group, an anthracenylene group and the like.
Examples of the heteroarylene group that can be used as L ¹ and L ² include the ring-structured groups described for the heteroaryl group that can be used as A ¹ and A ² described above.

  In formula (H1), nb and nc are integers of 0 to 5, preferably 1 to 3.

In one embodiment of the present invention, nb in formula (H1) is an integer of 1 to 5, and at least one linking group selected from nb L ¹ is a linking group represented by the following formula (X). It is preferable that nc is an integer of 1 to 5 and at least one linking group selected from nc L ² is a linking group represented by the following formula (X).

In formula (X), Z ^X1 represents a nitrogen atom or CR ^X1 . R ^X1 represents a hydrogen atom or a substituent. When R ^X1 is a substituent, examples thereof include the substituents which the above-mentioned hydrocarbon ring and heterocycle that can be adopted as A ¹ and A ² may have, and among them, an alkyl group is preferable.
* Represents a linking site with L ¹ , L ² , A ¹ , A ² , or D ¹ .

In one embodiment of the present invention, at least one linking group selected from nb L ¹ and nc L ² is a linking group represented by formula (X), an oxazole ring group, or a selenazole ring group. Preferably there is. More preferably, at least one linking group selected from nb L ¹ and nc L ² is a linking group represented by formula (X), and Z ^{X1 in} formula (X) is nitrogen. A linking group that is an atom (that is, a thiazole ring) is more preferable.

  In one embodiment of the present invention, the compound represented by the formula (H1) is preferably a compound represented by the following formula (H1-1).

In formula (H1-1), Z ^H1 , Z ^H2 and Z ^H3 represent a nitrogen atom or CR ⁿ . R ⁿ represents a hydrogen atom or a substituent.
R ^H1 , R ^H2 and R ^H3 represent a hydrogen atom or a substituent.
Examples of the substituent that can be used as R ⁿ , R ^H1 , R ^H2, and R ^H3 include the substituent that the above-described hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have.
nh1 and nh2 are integers of 0-4.
Each of A ¹ and ^{A 2} are the preferred form has the same meaning as ^{A 1} and ^{A 2} in the formula (H1) is the same. Is preferably represented by A ¹ and ^{A 2} are inter alia the formula (A-4) or (A-5), it is particularly preferable ^{that A 1} and ^{A 2} are represented by the above formula (A-5) .
However, in the formula (H1-1), at least one of the two Z ^H3 is a nitrogen atom, or nh1 is an integer of 1 to 4, and at least one Z ^H1 is a nitrogen atom, or nh2 is an integer from 1 to 4, at least one ^{Z H2} is a nitrogen atom.

  Specific examples of the compound represented by formula (H1) are shown below, but the present invention is not limited to these compounds.

  The hole transport layer 3 also preferably contains a compound represented by the following formula (H2-1) or (H2-2) as a hole transport material.

_{^{D 2 - (L 3) nd}} -C (R 1) = A 3 Equation (H2-1)
_{^{D 2 = (L 3) nd}} -C (R 1) = A 3 Equation (H2-2)

In the above formulas (H2-1) and (H2-2), A ³ represents an acceptor group, and D ² represents a donor group.

A ³ preferably has a ring structure and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring. A ³ preferably has a ring structure usually used as an acidic nucleus in a merocyanine dye, and specific examples of this ring structure include the following (a) to (q). In addition, the specific examples of the ring structure illustrated below are meant to include a form having a substituent, and examples of this substituent include a hydrocarbon ring and a heterocycle which can be adopted as A ¹ and A ² described above. There may be mentioned a substituent which may be possessed. In addition, “nucleus” is synonymous with “skeleton”.

(A) 1,3-Dicarbonyl nucleus: For example, 1,3-indandioneone, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, or 1,3-dioxane-4,6-. Zion.
(B) Pyrazolinone nucleus: for example, 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, or 1- (2-benzothiazoyl) -3-methyl-. 2-pyrazolin-5-one.
(C) Isoxazolinone nucleus: For example, 3-phenyl-2-isoxazolin-5-one, or 3-methyl-2-isoxazolin-5-one.
(D) Oxindole nucleus: For example, 1-alkyl-2,3-dihydro-2-oxindole.
(E) 2,4,6-Triketohexahydropyrimidine nucleus: for example barbituric acid or 2-thiobarbituric acid, or derivatives thereof. Examples of this derivative include 1-alkyl compounds such as 1-methyl and 1-ethyl; 1,3-dialkyl compounds such as 1,3-dimethyl, 1,3-diethyl and 1,3-dibutyl; 1,3-diphenyl. 1,3-Diaryl compounds such as 1,3-di (p-chlorophenyl) and 1,3-di (p-ethoxycarbonylphenyl); 1-alkyl-1-aryl compounds such as 1-ethyl-3-phenyl ; And 1,3-di (2-pyridyl) and other 1,3-diheterocyclic substituents.
(F) 2-Thio-2,4-thiazolidinedione nuclei: for example rhodanine and its derivatives. Examples of this derivative include 3-methylrhodanine, 3-ethylrhodonine, 3-allylrhodine, and other 3-alkylrhodanines; 3-phenylrhodamine and other 3-arylrhodanines; and 3- (2-pyridyl). ) 3-position heterocyclic ring-substituted rhodanine such as rhodanine.
(G) 2-thio-2,4-oxazolidinedione (2-thio-2,4- (3H, 5H) -oxazoledione) nucleus: for example 3-ethyl-2-thio-2,4-oxazolidinedione.
(H) Thianaphthenone nucleus: for example, 3 (2H) -thianaphthenone-1,1-dioxide.
(I) 2-Thio-2,5-thiazolidinedione nucleus: for example 3-ethyl-2-thio-2,5-thiazolidinedione.
(J) 2,4-thiazolidinedione nucleus: for example, 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, or 3-phenyl-2,4-thiazolidinedione.
(K) Thiazolin-4-one nucleus: 4-thiazolinone, or 2-ethyl-4-thiazolinone, for example.
(L) 2,4-imidazolidinedione (hydantoin) nucleus: for example, 2,4-imidazolidinedione or 3-ethyl-2,4-imidazolidinedione.
(M) 2-Thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus: 2-thio-2,4-imidazolidinedione, or 3-ethyl-2-thio-2,4-imidazolidine Zion etc.
(N) 2-Imidazolin-5-one nucleus: for example 2-propylmercapto-2-imidazolin-5-one.
(O) 3,5-Pyrazolidinedione nucleus: for example, 1,2-diphenyl-3,5-pyrazolidinedione or 1,2-dimethyl-3,5-pyrazolidinedione.
(P) Benzothiophen-3-one nucleus: for example, benzothiophen-3-one, oxobenzothiophen-3-one, or dioxobenzothiophen-3-one.
(Q) Indanone nucleus: For example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1-indanone, or 3,3-dimethyl-1-indanone.

A ³ is preferably a 1,3-dicarbonyl nucleus, a pyrazolinone nucleus, a 2,4,6-triketohexahydropyrimidine nucleus (including a thioketone body, for example, barbituric acid, 2-thiobarbituric acid, and the like below). ), 2-thio-2,4-thiazolidinedione nucleus, 2-thio-2,4-oxazolidinedione nucleus, 2-thio-2,5-thiazolidinedione nucleus, 2,4-thiazolidinedione nucleus, 2,4- Structure of imidazolidinedione nucleus, 2-thio-2,4-imidazolidinedione nucleus, 2-imidazolin-5-one nucleus, 3,5-pyrazolidinedione nucleus, benzothiophen-3-one nucleus, or indanone nucleus And more preferably 1,3-dicarbonyl nucleus, 2,4,6-triketohexahydropyrimidine nucleus, 3,5-pyrazolidinedione nucleus, benzothiophen-3- It has a structure of an on nucleus or an indanone nucleus, more preferably a structure of a 1,3-dicarbonyl nucleus, or a 2,4,6-triketohexahydropyrimidine nucleus, and particularly preferably a 1,3-indane nucleus. It has a dione structure or a structure of barbituric acid or 2-thiobarbituric acid or a derivative thereof.

When A ³ is 1,3-indandione, A ³ is preferably represented by the following general formula (IV).

In formula (IV), R ^{41 to} R ⁴⁴ represent a hydrogen atom or a substituent. * Indicates a connection site. Examples of the substituent that can be adopted as R ^{41 to} R ⁴⁴ include the substituents that may be possessed by the hydrocarbon ring and heterocycle that can be adopted as A ¹ and A ² described above. Among these, this substituent is preferably an alkyl group, and more preferably an alkyl group having 1 to 6 carbon atoms.
In addition, adjacent groups of R ^{41 to} R ⁴⁴ may combine to form a ring. Among them, it is preferable that R ⁴² and R ⁴³ are bonded to each other to form a ring (preferably a benzene ring, a pyridine ring or a pyrazine ring). When R ⁴² and R ⁴³ combine to form a ring, R ⁴¹ and R ⁴⁴ are preferably hydrogen atoms.
It is also preferable that all of R ^{41 to} R ^{44 in} the general formula (IV) are hydrogen atoms.

The form in which R ⁴² and R ⁴³ of the general formula (IV) are bonded to each other to form a ring is preferably represented by the following general formula (V).

In formula (V), R ⁴¹ and R ⁴⁴ have the same meanings as R ⁴¹ and R ⁴⁴ in formula (IV), respectively. R ⁴¹ and R ⁴⁴ are preferably hydrogen atoms. * Indicates a connection site.

In formula (V), R ^{45 to} R ⁴⁸ represent a hydrogen atom or a substituent. Examples of this substituent include the substituents that the hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have. Of these, this substituent is preferably an alkyl group, and more preferably an alkyl group having 1 to 6 carbon atoms.
It is preferable that R ^{45 to} R ⁴⁸ are all hydrogen atoms. That is, in the compound represented by the general formula (V), all of R ⁴¹ , R ⁴⁴ , and R ^{45 to} R ⁴⁸ are preferably hydrogen atoms.

D ² is preferably a group having an amino group (—NR ^a (R ^b )). More preferably, ^{D 2} is ^-NR a ^{(R b)} one having an aryl group (preferably, ^-NR a ^{(R b)} one having a phenyl group or a naphthyl group as a substituent) as a substituent is.
R ^a and R ^b represent a hydrogen atom or a substituent. Examples of the substituent that can be used as R ^a or R ^b include the substituents that the above-described hydrocarbon ring and heterocycle that can be used as A ¹ and A ² may have. Among these, this substituent is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a silyl group, or an aromatic heterocyclic group (preferably a 5-membered ring, specific examples thereof are furan, thiophene, pyrrole, oxadiazole). Is preferred.
D ² preferably contains a condensed ring structure composed of 3 or more rings.

L ³ represents a linking group, and nd is an integer of 0 to 5. L ³ is preferably alkylene, alkenylene group, alkynylene, arylene or heteroarylene, and particularly preferably alkenylene, arylene or heteroarylene. The number of atoms constituting the L ³ is preferably 1 to 100, 2 to 25 and particularly Konomashiii.
nd is preferably 0 to 3, more preferably 0 or 1, and particularly preferably 0.

R ¹ represents a hydrogen atom or a substituent. Examples of the substituent that can be used as R ¹ include the substituents that the hydrocarbon ring and heterocycle that can be used as A ¹ and A ² described above may have. R ¹ is preferably a hydrogen atom.

  The compound represented by the formula (H2-1) is more preferably represented by the following formula (H2-1-1), (H2-1-2) or (H2-1-3).

In formulas (H2-1-1), (H2-1-2) and (H2-1-3), E represents a ring structure. Ring E is preferably a monocycle. Ring E is more preferably a 5-membered ring or a 6-membered ring.
G represents a heterocyclic structure containing a nitrogen atom as a ring-constituting atom. Ring G is preferably a monocycle. Ring G is more preferably a 5-membered ring or a 6-membered ring.
R < ² > -R < ⁴ > shows a substituent, ne is an integer of 0-4, nf is an integer of 0-3, nh is an integer of 0-5, and ng is 0 or 1. Examples of the substituent that can be used as R ^{2 to} R ⁴ include the substituents that the hydrocarbon ring and heterocycle that can be used as A ¹ and A ² described above may have.
L ³ , nd and A ³ have the same meanings as L ³ , nd and A ³ in formula (H2-1), respectively.

  Specific examples of the compound represented by the above formula (H2-1) or (H2-2) are shown below, but the present invention is not limited to these forms.

The hole transport layer 3 also preferably contains a compound represented by the following Formula 1-1 or Formula 1-2 as a hole transport material. This hole-transporting material may have one or more cation sites or anion sites in the molecule as long as the charges are balanced as a whole.
The hole transport material may have an optional substituent, but not to have -COOH and -NH _2. When the hole transport material has —COOH or —NH ₂ , a high fill factor cannot be imparted.

In the compound represented by the following formula 1-1 or the following formula 1-2, when the double bond in the chemical formula can be either E type or Z type, it may be either of them unless otherwise specified. , Or a mixture thereof.
Moreover, when various isomers are present in the compound represented by the following formula 1-1 or the following formula 1-2, or when a plurality of resonance structures can be adopted, one of them is represented by the following formula 1-1 or the following. When it can be represented by Formula 1-2, it is a compound represented by Formula 1-1 or Formula 1-2 below, regardless of other isomers or resonance structures. However, regarding a partial structure that can be represented by a benzene ring or a thiophene ring, a resonance structure formed by breaking the partial structure is not considered.

In the formula, X ^{1 to} X ⁴ represent an oxygen atom, a sulfur atom, a group represented by the following formula 1-a, a group represented by the following formula 1-b, or = C (G ¹ ) (G ² ). . Each of X ^{1 to} X ⁴ is preferably an oxygen atom, a group represented by the following formula 1-a, a group represented by the following formula 1-b, or ═C (G ¹ ) (G ² ). One of X ¹ and X ² and one of X ³ and X ⁴ are preferably an oxygen atom, a sulfur atom or ═C (G ¹ ) (G ² ), and more preferably an oxygen atom. The other of X ¹ and X ^{2 and} the other of X ³ and X ⁴ are preferably a group represented by the following formula 1-a or a group represented by the following formula 1-b.

Y ^{1 to} Y ⁴ represent OR, SR, O ⁻ , S ⁻ , a halogen atom, a group represented by the following formula 1-c, or a group represented by the following 1-d. Each of Y ^{1 to} Y ⁴ is preferably OR, SR, O ⁻ , S ⁻ , a group represented by the following formula 1-c or a group represented by the following 1-d. One of Y ¹ and Y ² and one of Y ³ and Y ⁴ are preferably OR, SR, O ⁻ , S ⁻ or a halogen atom, and more preferably OR, SR, O ⁻ or S ⁻ , and OR. Or O ⁻ is more preferable. The other of Y ¹ and Y ^{2 and} the other of Y ³ and Y ⁴ are preferably a group represented by the following formula 1-c or a group represented by the following 1-d.

The hole transport material represented by Formula 1-1 and the hole transport material represented by Formula 1-2 each contain at least one group represented by any one of the following Formula 1-a to Formula 1-d. Have one. That is, at least one of X ¹ , X ² , Y ^1, and Y ² in Formula 1-1 is a group represented by any one of Formula 1-a to Formula 1-d below. Further, in Formula 1-2, at least one of X ³ , X ⁴ , Y ³ and Y ⁴ is a group represented by any one of Formula 1-a to Formula 1-d below. The number of the hole transport material represented by each formula having a group represented by any one of the following formulas 1-a to 1-d is preferably 2 or more, and more preferably 2. preferable.

When it has two groups represented by any one of the following formulas 1-a to 1-d, it is not particularly limited, and it is preferable that X ² and Y ^{1 in} formula 1-1 take the above groups, It is preferable that Y ³ and Y ^{4 in} 1-2 have the above groups.
When having two groups represented by any one of formula 1-a to formula 1-d, the combination of groups represented by any one of formula 1-a to formula 1-d is not particularly limited, Examples include a combination of any one of 1-a and formula 1-b and one of formula 1-c and formula 1-d, a combination of two kinds selected from formula 1-c and formula 1-d, and the like. To be A combination represented by Formulas 2-1 to 2-5 described later is preferable.

In the above = C (G ¹ ) (G ² ), which may be used as X ^{1 to} X ⁴ , G ¹ and G ² each represent an electron-withdrawing group. In the present invention, the electron-withdrawing group refers to a group having a property of reducing the electron density of ═C or a binding site with ═C by an inducing effect and / or a mesomeric effect. As the electron withdrawing group include a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom), a nitro group, a cyano group, a sulfonyl group, a phosphoryl group, an azide group (-N _3), a carbonyl group, an alkoxy Examples thereof include a carbonyl group, an aryloxycarbonyl group and a heterocyclic oxycarbonyl group, and a halogen atom is preferable. Examples of the alkoxycarbonyl group, the aryloxycarbonyl group, and the heterocyclic oxycarbonyl group include each group in the substituent group T described later. For the sulfonyl group, the alkyl, cycloalkyl or arylsulfonyl group in the substituent group T described later can be referred to.
However, the electron-withdrawing groups that can be used as G ¹ and G ² do not include a carboxy group, and preferably do not include an acidic group. Here, the acidic group is a group having a dissociative proton and has a pKa of 11 or less. The pKa of the acidic group is as described in J. Phys. Chem. A2011, 115, p. It can be determined according to the “SMD / M05-2X / 6-31G ^* ” method described in pp. Examples of the acidic group include a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, a phenolic hydroxyl group, and a sulfonamide group in addition to the carboxy group.
G ¹ and G ² do not combine with each other to form a ring. When G ¹ and G ² are linked to each other to form a ring, the group formed is included in the group represented by Formula 1-a described later.
The combination of G ¹ and G ² is not particularly limited and is appropriately determined. Examples of preferable combinations include cyano groups, an alkoxycarbonyl group and a cyano group, and the like.

As R of OR and SR which can be taken as Y ^{1 to} Y ⁴ , a hydrogen atom or a substituent is shown, and a hydrogen atom is preferable. The substituent is not particularly limited and is preferably selected from the substituent group T described later. More preferable substituents include “more preferable groups selected from the substituent group T” described later.
Examples of the halogen atom that can be used as Y ^{1 to} Y ⁴ include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The groups represented by the following formula that can be adopted as X ^{1 to} X ⁴ and Y ^{1 to} Y ⁴ will be described.
In the following formula, * represents a linking site with the carbon four-membered ring structure in formula 1-1 or formula 1-2.

In Formula 1-a, A ¹ represents a hydrocarbon ring or a hetero ring, and the hetero ring is preferable.
The hydrocarbon ring in A ¹ is a hydrocarbon ring in which L ¹ or the single ring bonded to the above carbon four-membered ring structure is a hydrocarbon ring, and may include a heterocycle (may be fused). Further, the heterocycle in A ¹ is a heterocycle in which a monocycle bonded to L ¹ or the above carbon four-membered ring structure is a heterocycle, and may include a hydrocarbon ring.
The hydrocarbon ring or hetero ring may be a cation for canceling the charge, if desired.
The hydrocarbon ring and the heterocycle A ¹ are rings capable of bonding to L ¹ or the above carbon four-membered ring structure with one ring-constituting atom from which two hydrogen atoms have been removed. Such a hydrocarbon ring or hetero ring may be an aliphatic ring or an aromatic ring, and may be a single ring or a condensed ring (fused ring). When the hydrocarbon ring is a condensed ring, a condensed hydrocarbon ring in which the hydrocarbon rings are condensed with each other can be mentioned. When the heterocycle is a condensed ring, a heterocycle in which two or more rings including at least one heterocycle are condensed is preferable, and for example, a condensed heterocycle in which heterocycles are condensed, an aliphatic heterocycle or an aromatic ring. Examples thereof include a hetero ring in which a hetero ring and an aromatic hydrocarbon ring are condensed.
The monocyclic hydrocarbon ring and heterocyclic ring (including a ring forming a condensed ring) are preferably a 5-membered ring or a 6-membered ring.

  Among the hydrocarbon rings, examples of the aromatic hydrocarbon ring include a ring forming an aryl group in the substituent group T described later. Further, among the hydrocarbon rings, examples of the aliphatic hydrocarbon ring include a ring forming each group such as a cycloalkyl group and a cycloalkenyl group in the substituent group T described later.

The heterocycle has at least one heteroatom as a ring-constituting atom, for example, an oxygen atom, a sulfur atom or a nitrogen atom, and is preferably a ring having 2 to 20 carbon atoms.
Among the heterocycles represented by A ¹ , the aromatic heterocycle may be one that exhibits aromaticity as a whole ring, and examples thereof include a ring forming an aromatic heterocycle group in the substituent group T described later, and two of these. Examples thereof include a condensed (condensed) heterocyclic ring or a condensed (condensed) heterocyclic ring in which one or more rings forming an aromatic heterocyclic group and the above hydrocarbon ring are condensed. Here, aromaticity means satisfying Huckel's rule. Examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, a pyrrole ring, a furan ring, a thiazole ring, an oxazole ring, a single ring such as an imidazole ring, a benzothiophene ring, a benzofuran ring, a benzopyrrole ring, a benzothiazole ring, and a benzothiazole ring. Examples thereof include condensed rings such as an oxazole ring, a benzimidazole ring, a fluorene ring, a carbazole ring, and a quinoline ring.

Among the heterocycles represented by A ¹ , the aliphatic heterocycle may be one that does not exhibit aromaticity as a whole ring, and includes, for example, a ring forming an aliphatic heterocycle group in the substituent group T described later, or a condensed ring. Examples of the ring include a ring containing a ring forming this aliphatic heterocyclic group. Examples of the aliphatic heterocycle include a pyrrolidine ring, an imidazolidine ring, a thiazolidine ring, an oxazolidine ring, a pyrazolidine ring, a piperidine ring, a piperazine ring, a tetrahydrofuran ring, a tetrathiophene ring, a pyrroline ring, a thiazoline ring, an imidazoline ring and a pyrazoline ring. The monocycle of is mentioned. Examples of the condensed ring (heterocycle in which two or more rings are condensed) include, for example, a condensed ring of the above monocycle and a benzene ring (indoline ring, benzoxazoline, benzothiazoline, chroman ring, etc.), and The aliphatic hetero-condensed ring included in the exemplified compound is.

Among them, as A ¹ , an aliphatic heterocycle is preferable, a condensed aliphatic heterocycle is more preferable, and an indoline ring, benzoxazoline, benzothiazoline and the like are further preferable.

A ¹ may have a substituent. The substituent that A ¹ may have is not particularly limited, and examples thereof include a “more preferable group selected from the substituent group T” described later, the electron-withdrawing group, an oxo group or a thioxo group, and the like. Can be mentioned. The substituent that A ¹ may have may be further substituted with a substituent. Examples of such a group include a group formed by combining a plurality (preferably 2 to 5) of groups selected from the substituent group T. Examples thereof include an aromatic heterocycle substituted with an alkyl group, a halogenated alkyl group, a halogenated aryl group, and further, a specific substituent containing Z ⁷ and V ⁷ represented by Formula 6-1 described later. To be

In Formula 1-a, L ¹ represents a linking group. This L ¹ may be any group as long as it connects A ¹ to the carbon four-membered ring structure in Formula 1-1, and is a connecting group in which two hydrogen atoms are removed from each of the two atoms, four hydrogen atoms in total. is there. In the case where the formula 1-a has two L ¹ 's (when na is 2), the two L ^1- bonded groups connect A ¹ and the above carbon four-membered ring structure to each other. The binding mode between L ¹ 's is not particularly limited. This bonding mode is both a mode in which two L ¹ are bonded by a single bond (= L ¹ -L ¹ =) and a mode in which two L ¹ are bonded by a double bond (= L ¹ = L ¹ =). Includes.
Examples of the linking group that can be used as L ¹ include a group composed of an aliphatic hydrocarbon, a group composed of an aromatic hydrocarbon, a group composed of an aromatic heterocycle, a group composed of an aliphatic heterocycle, and the like.
As the group consisting of the above aliphatic hydrocarbon, a group consisting of a methane hydrocarbon (alkane), a group consisting of an ethylene hydrocarbon (alkene), or a group consisting of an acetylene hydrocarbon (alkyne) is preferable. Each of these groups may be linear, branched or cyclic. The number of carbon atoms of the linear and branched aliphatic hydrocarbon group is not particularly limited and is preferably 1 to 36, more preferably 1 to 18, further preferably 1 to 12, and 1 to 6 respectively. Particularly preferred. The cyclic aliphatic hydrocarbon group may be monocyclic or polycyclic, and the carbon number thereof is not particularly limited, preferably 3 to 36, more preferably 3 to 18, and further preferably 5 to 10.

The carbon number of the group consisting of the aromatic hydrocarbon is not particularly limited and is preferably 6 to 22, more preferably 6 to 18, and further preferably 6 to 10. Examples of the group composed of an aromatic hydrocarbon include a group composed of a benzene ring and a group composed of a naphthalene ring.
The aromatic heterocycle that forms the group consisting of the aromatic heterocycle is not particularly limited, and the aromatic heterocycle that can be used as A ¹ can be applied.
The aliphatic heterocycle forming the group consisting of the aliphatic heterocycle is not particularly limited, and the aliphatic heterocycle that can be adopted as A ¹ can be applied.

Among the above, L ¹ is preferably a group consisting of an aliphatic hydrocarbon, more preferably a group consisting of a methane hydrocarbon.
L ¹ may have a substituent. The substituent that L ¹ may have is not particularly limited, and examples thereof include a “more preferable group selected from the substituent group T” described later.

  In Formula 1-a, na is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

In Formula 1-a, the combination of A ¹ and L ¹ is not particularly limited, and examples thereof include a combination of the preferable one of A ^{1 and} the preferable one of L ¹ .

In Formula 1-b, B ¹ represents a heterocycle or NR ^N1 R ^N2 .
The heterocycle that can be taken as B ¹ is a heterocycle that can bond to L ² with one ring-constituting atom from which one hydrogen atom has been removed, and can be taken as A ¹ except that it can be bonded to L ² with a single bond. It has the same meaning as a heterocycle and the preferred ones are also the same.
NR ^N1 R ^N2 that can be taken as B ¹ is a substituted amino group, and R ^N1 and R ^N2 are not linked to each other to form a (nitrogen-containing hetero) ring. When R ^N1 and R ^N2 are linked to each other to form a ring, the group formed is included in a (nitrogen-containing) heterocycle that can be used as B ¹ . R ^N1 and R ^N2 each represent a substituent, and preferably include a “more preferable group selected from the substituent group T” described later, more preferably an aryl group, and further preferably a phenyl group. R ^N1 and R ^N2 may be the same or different.
B ¹ may have a substituent. The substituent that B ¹ may have is not particularly limited and has the same meaning as the substituent that A ¹ may have.

In the hole transport material represented by Formula 1-1 and Formula 1-2, when an acyclic substituted amino group is present in X ^{1 to} X ⁴ and Y ^{1 to} Y ^4, among the substituted amino groups, The substituted amino group closest to the carbon four-membered ring structure is not a substituent which B ¹ may have, but NR ^N1 R ^N2 which can be taken as B ¹ .

In Formula 1-b, L ² represents a linking group. This L ² may be a group that is a single bond to B ¹ and that is linked to the carbon four-membered ring structure in formula 1-1 by a double bond, and it may be one atom, two atoms, or another atom. Is a linking group from which one hydrogen atom, three hydrogen atoms in total, have been removed. In the case where the formula 1-b has two L ² 's (when nb is 2), the group to which the ^two L ^2's are bonded connects the B ¹ and the carbon four-membered ring structure to each other. The bonding mode of L ² is not particularly limited. This bonding mode is both a mode in which two L ² are bonded by a single bond (-L ² -L ² =) and a mode in which ^two L ² are bonded by a double bond (-L ² = L ² =). Includes.
Examples of the linking group that can be used as L ² include a group composed of an aliphatic hydrocarbon, a group composed of an aromatic hydrocarbon, a group composed of an aromatic heterocycle, a group composed of an aliphatic heterocycle, and the like. These groups have the same meanings as the above corresponding groups that can be adopted as L ¹ except that the number of hydrogen atoms to be removed is different, and the preferred ones are also the same.
L ² may have a substituent. The substituent that L ² may have is not particularly limited, and examples thereof include a “more preferable group selected from the substituent group T” described later.

  In Formula 1-b, nb is 1 or 2, and 1 is preferable.

In Formula 1-b, the combination of B ¹ and L ² is not particularly limited, and examples thereof include a combination of preferable B ^{1 and} a preferable combination of L ² (L ¹ ).

In Formula 1-c, A ¹ represents a hydrocarbon ring or a heterocycle. A ¹ in formula 1-c has the same meaning as A ¹ in formula 1-a, and the preferred ones are also the same.

In Formula 1-c, L ³ represents a linking group. This L ³ may be a group that is a double bond to A ¹ and is connected to the carbon four-membered ring structure in Formula 1-2 by a single bond, and may be one atom, two atoms, or another atom. Is a linking group from which one hydrogen atom, three hydrogen atoms in total, have been removed. When having two L ³ in formula 1-c (if nc is 2), if a group of two L ³ bound is long and connects the A ¹ and the carbon four-membered ring structure, two The binding mode between L ³ 's is not particularly limited. This bonding mode is both a mode in which two L ³ are bonded by a single bond (= L ³ −L ³ −) and a mode in which two L ³ are bonded by a double bond (= L ³ = L ³ −). Includes.
Examples of the linking group that can be used as L ³ include a group composed of an aliphatic hydrocarbon, a group composed of an aromatic hydrocarbon, a group composed of an aromatic heterocycle, a group composed of an aliphatic heterocycle, and the like. These groups have the same meanings as the above corresponding groups that can be adopted as L ¹ except that the number of hydrogen atoms to be removed is different, and the preferred ones are also the same.
L ³ may have a substituent. The substituent that L ³ may have is not particularly limited, and examples thereof include a “more preferable group selected from the substituent group T” described later.

  In Formula 1-c, nc is 1 or 2, and 1 is preferable.

In Formula 1-c, the combination of A ¹ and L ³ is not particularly limited, and examples thereof include a combination of the preferred one of A ^{1 and} a preferred one of L ³ (L ¹ ).

In Formula 1-d, B ¹ represents a hydrocarbon ring or NR ^N1 R ^N2 . B ¹ in Formula 1-d has the same meaning as B ¹ in Formula 1-b, and the preferred ones are also the same.

In Formula 1-d, L ⁴ represents a linking group. This L ⁴ may be a group that is a single bond to B ¹ and is also a single bond to the carbon four-membered ring structure in Formula 1-2, one from each of two atoms, and two hydrogen in total. It is a linking group with an atom removed. However, in the case where the formula 1-d has two L ⁴ 's (when nd is 2), the group to which the two L ^4's are bonded connects B ¹ to the carbon four-membered ring structure, The binding mode between the two L ⁴ 's is not particularly limited. This binding mode may include a mode where two ^{L 4} are bonded by a single bond ^{(-L 4 -L} 4 -) - both aspects with, aspects connected with a double bond ^{(-L 4} = ^L 4) Includes.
Examples of the linking group that can be used as L ⁴ include a group consisting of an aliphatic hydrocarbon, a group consisting of an aromatic hydrocarbon, a group consisting of an aromatic heterocycle, a group consisting of an aliphatic heterocycle, and the like. These groups have the same meanings as the above corresponding groups that can be adopted as L ¹ except that the number of hydrogen atoms to be removed is different, and the preferred ones are also the same.
L ⁴ may have a substituent. The substituent that L ⁴ may have is not particularly limited, and examples thereof include a “more preferable group selected from the substituent group T” described later.

  In Formula 1-d, nd is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

In Formula 1-d, the combination of B ¹ and L ⁴ is not particularly limited, and examples thereof include a combination of preferable B ^{1 and} a preferable combination of L ⁴ (L ¹ ).

The hole transport material contained in the hole transport layer 3 is preferably one represented by any one of the following formula 2-1 to the following formula 2-5.

The hole transport material represented by the above formula 2-1 has the group represented by the formula 1-a as X ² in the above formula 1-1, and the group represented by the formula 1-d as Y ^1. It is a preferable embodiment having.
A ² represents a heterocycle, and this heterocycle has the same meaning as the heterocycle that can be adopted as A ¹ in the above formula 1-a, and the preferred ones are also the same. L ⁶ represents a linking group, has the same meaning as the linking group that can be adopted as L ¹ in the above formula 1-a, and the preferred ones are also the same. nf is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
L ⁵ represents a linking group and has the same meaning as the linking group that can be adopted as L ⁴ in the above formula 1-d, and the preferred ones are also the same. R ¹ and ^{R 2} each represents a substituent, except that it may be linked to each other as described below, ^{R N1} and ^{R N2} of ^NR N1 ^{R N2,} which can take as ^{B 1} in the above formula 1-d It has the same meaning as above, and the preferred ones are the same. ne is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
Y ⁵ represents OR, SR, O ⁻ , S ⁻ or a halogen atom, has the same meaning as OR, SR, O ⁻ , S ⁻ or a halogen atom which can be taken as Y ² , and the preferable ones are also the same. X ⁶ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), which has the same meaning as an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ) that can be used as X ¹ , and is preferable. The same is true. It is preferable that Y ⁵ is OR or O ⁻ , and X ⁶ is an oxygen atom.

The hole transport material represented by the above formula 2-2 has a group represented by the formula 1-b as X ² in the above formula 1-1, and a group represented by the formula 1-d as Y ^1. It is a preferable embodiment having.
B ² represents a heterocycle, and this heterocycle has the same meaning as the heterocycle that can be adopted as B ¹ in the above formula 1-b, and the preferred ones are also the same. L ⁸ represents a linking group, has the same meaning as the linking group that can be adopted as L ² in the above formula 1-b, and the preferred ones are also the same. nh is 1 or 2, and 1 is preferable.
L ⁷ represents a linking group, has the same meaning as the linking group that can be adopted as L ⁴ in the above formula 1-d, and the preferred ones are also the same. R ³ and R ⁴ each represent a substituent and are synonymous with R ^N1 and R ^N2 of NR ^N1 R ^N2 that can be taken as B ¹ in the above formula 1-d, except that they may be linked to each other. The same applies to the preferred ones. ng is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
Y ⁶ represents OR, SR, O ⁻ , S ⁻ or a halogen atom, has the same meaning as OR, SR, O ⁻ , S ⁻ or a halogen atom which can be taken as Y ² , and the preferable ones are also the same. X ⁷ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), which has the same meaning as an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), which can be used as X ¹ , and is preferable. The same is true. It is preferred that Y ⁶ is OR or O ⁻ , and X ⁷ is an oxygen atom.

The hole transport material represented by the above formula 2-3 is a preferred embodiment having both the groups represented by the formula 1-d as Y ³ and Y ⁴ in the above formula 1-2.
L ⁹ and L ¹⁰ each represent a linking group, which has the same meaning as the linking group that can be adopted as L ⁴ in the above formula 1-d, and the preferred ones are also the same. L ⁹ and L ¹⁰ may be the same or different.
R ^{5 to} R ⁸ each represent a substituent, and are synonymous with R ^N1 and R ^N2 of NR ^N1 R ^N2 that may be taken as B ¹ in the above formula 1-d, except that they may be linked to each other. The same applies to the preferred ones. ni and nj are integers of 0 to 2, preferably 0 or 1, and more preferably 0.
X ⁸ and ^{X 9} are both an oxygen atom, a sulfur atom or ^{= C (G 1) (G} 2) , oxygen atom can take as ^{X 3,} sulfur atom or ^{= C (G 1) (G} 2) It has the same meaning as above, and the preferred ones are also the same. Both X ⁸ and X ⁹ are preferably OR or O ⁻ , and may be the same or different.

The hole transport material represented by the above formula 2-4 has a group represented by the formula 1-a or an oxygen atom as X ² in the above formula 1-1, and is represented by the formula 1-c as Y ^1. Is a preferred embodiment having a group
A ⁴ represents a heterocycle in which two or more rings are condensed or an oxygen atom, and a heterocycle in which two or more rings are condensed is preferable. The heterocyclic ring that can be used as A ⁴ has the same meaning as the heterocyclic ring that is a condensed ring of two or more rings that can be used as A ¹ in the above formula 1-a, and the preferred ones are also the same.
L ¹¹ represents a linking group, has the same meaning as the linking group that can be adopted as L ³ in the above formula 1-c, and the preferred ones are also the same. A ³ represents a heterocycle and has the same meaning as the heterocycle that can be adopted as A ¹ in the above formula 1-c, and the preferred ones are also the same. nk is 1 or 2, and 1 is preferable.
Y ⁷ represents OR, SR, O ⁻ , S ⁻ or a halogen atom, has the same meaning as OR, SR, O ⁻ , S ⁻ or a halogen atom which can be taken as Y ² , and the preferable ones are also the same. X ¹⁰ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), which has the same meaning as an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ) that can be used as X ¹ , and is preferable. The same is true. It is preferred that Y ⁷ is OR or O ⁻ , and X ¹⁰ is an oxygen atom.

The hole transport material represented by the formula 2-5 has a group represented by the formula 1-b as X ^{2 in the} formula 1-1, and a group represented by the formula 1-c as Y ^1. It is a preferable embodiment having.
B ³ represents a heterocycle, and this heterocycle has the same meaning as the heterocycle that can be adopted as B ¹ in the above formula 1-b, and the preferred ones are also the same. L ¹³ represents a linking group and has the same meaning as the linking group that can be adopted as L ² in the above formula 1-b, and the preferred ones are also the same. nm is 1 or 2, and 1 is preferable.
L ¹² represents a linking group, has the same meaning as the linking group that can be adopted as L ³ in the above formula 1-c, and the preferred ones are also the same. A ⁵ represents a heterocycle and has the same meaning as the heterocycle that can be used as A ¹ in the above formula 1-c, and the preferred ones are also the same. nl is 1 or 2, and 1 is preferable.
Y ⁸ represents OR, SR, O ⁻ , S ⁻ or a halogen atom, has the same meaning as OR, SR, O ⁻ , S ⁻ or a halogen atom which can be taken as Y ² , and the preferable ones are also the same. X ¹¹ represents an oxygen atom, a sulfur atom or ═C (G ¹ ) (G ² ), which has the same meaning as an oxygen atom, a sulfur atom or ═C (G ¹ ) (G ² ), which can be used as X ¹ , and is preferable. The same is true. It is preferred that Y ⁸ is OR or O ⁻ , and X ¹¹ is an oxygen atom.

In each of the above formulas, two of R ^{1 to} R ⁸ , that is, R ¹ and R ² , R ³ and R ⁴ , R ⁵ and R ⁶ , and each substituent of R ⁷ and R ⁸ are, respectively, , May form a ring by being bonded to each other (corresponding to a hetero ring that can be taken as B ¹ ) or need not be formed (corresponding to NR ^N1 R ^N2 that can be taken as B ¹ ).

The hole transport material contained in the hole transport layer 3 is more preferably one represented by any one of the following formulas 3-1 to 3-3.

The hole transport material represented by the above formula 3-1 has the group represented by the formula 1-b as X ² in the above formula 1-1, and the group represented by the formula 1-d as Y ^1. This is a more preferable embodiment.
B ⁴ represents a heterocycle, has the same meaning as B ² in the above formula 2-2, and the preferred ones are also the same. R ¹¹ represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be used as R ¹¹ is not particularly limited and is preferably selected from the substituent group T described below.
L ¹⁴ represents a linking group, has the same meaning as L ⁷ in the above formula 2-2, and the preferred ones are also the same. R < ⁹ > and R < ¹⁰ > each represent a substituent and have the same meaning as R < ³ > and R < ⁴ > in the above formula 2-2, and the preferred ones are also the same. nn is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
Y ⁹ represents OR, SR, O ⁻ or S ⁻ , has the same meaning as OR ⁶ , SR, O ⁻ or S ⁻ which can be adopted as Y ⁶ , and the preferable ones are also the same. X ¹² represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), and has the same meaning as that which can be adopted as X ⁷ , and the preferred ones are also the same. The combination of Y ⁹ and X ¹² is preferably Y ⁹ is OR or O ⁻ and X ¹² is an oxygen atom.

The hole transporting material represented by the above formula 3-2 has a group represented by the formula 1-a or an oxygen atom as X ² in the above formula 1-1, and is represented by the formula 1-c as Y ^1. Is a more preferred embodiment having a group
A ⁷ represents a heterocycle in which two or more rings are condensed or an oxygen atom, and a heterocycle in which two or more rings are condensed is preferable. A ⁷ has the same meaning as A ⁴ in the above formula 2-4, and the preferred ones are also the same.
A ⁶ represents a heterocycle, has the same meaning as A ³ in the above formula 2-4, and the preferred ones are also the same. R ¹² represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be used as R ¹² is not particularly limited and is preferably selected from the substituent group T described below.
Y ¹⁰ represents OR, SR, O ⁻ or S ⁻ , has the same meaning as OR, SR, O ⁻ or S ⁻ which can be adopted as Y ⁷ , and the preferable ones are also the same. X ¹³ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), has the same meanings as those that can be adopted as X ¹⁰ , and preferable ones are also the same. A combination in which Y ¹⁰ is OR or O ⁻ and X ¹³ is an oxygen atom is preferable.

The hole transport material represented by the formula 3-3 has a group represented by the formula 1-b as X ^{2 in the} formula 1-1, and a group represented by the formula 1-c as Y ^1. This is a more preferable embodiment.
B ⁵ represents a heterocycle, has the same meaning as B ³ in the above formula 2-5, and the preferred ones are also the same. R ¹⁴ represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be used as R ¹⁴ is not particularly limited and is preferably selected from the substituent group T described below.
A ⁸ represents a heterocycle, has the same meaning as A ⁵ in the above formula 2-5, and the preferred ones are also the same. R ¹³ represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be used as R ¹³ is not particularly limited and is preferably selected from the substituent group T described below.
Y ¹¹ is, OR, SR, O ^- or S ^- indicates, OR can take as ^{Y 8,} SR, O ^- or S ^- with the same meaning, it is preferable also the same. X ¹⁴ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), and has the same meanings as those that can be adopted as X ¹¹ , and the preferred ones are also the same. A combination in which Y ¹¹ is OR or O ⁻ and X ¹⁴ is an oxygen atom is preferable.

B ⁴ in the above formula 3-1, A ⁶ in the above formula 3-2, and A ⁸ and B ⁵ in the above formula 3-3 can each have a heterocyclic ring in which two or more rings are condensed. Ringed heterocycles are preferred.

The hole transport material contained in the hole transport layer 3 is more preferably one represented by any one of the following formulas 5-1 to 5-3.

The hole transport material represented by the above formula 5-1 has a group represented by the formula 1-b as X ² in the above formula 1-1, and a group represented by the formula 1-d as Y ^1. It is one more preferable embodiment having.
L ¹⁷ represents a linking group, has the same meaning as L ⁷ in the above formula 2-2, and the preferable ones are also the same. R ¹⁸ and R ¹⁹ each represent a substituent and have the same meaning as R ³ and R ⁴ in the above formula 2-2, and the preferable ones are also the same. nq is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
V ¹ represents N ⁺ R ^N3 or a nitrogen atom. R ^N3 represents a hydrogen atom or a substituent. The substituent that can be used as R ^N3 is not particularly limited and is, for example, selected from the substituent group T described later, and is preferably an alkyl group.
Z ¹ represents CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5, and an oxygen atom or a sulfur atom is preferable. R ^C1 , R ^C2 and R ^N5 each represent a hydrogen atom or a substituent. The substituent is not particularly limited and is selected from, for example, the substituent group T described later.
R ^{21 to} R ²⁴ each represent a hydrogen atom or a substituent. The substituent that can be used is not particularly limited and is selected from, for example, the substituent group T described later. At least one of R ^{21 to} R ²⁴ is preferably an electron-withdrawing group, and more preferably 1 to 2 is an electron-withdrawing group.
R ²⁰ represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. R ²⁰ has the same meaning as R ¹¹ , and the preferred ones are also the same.
Y ¹³ represents OR or O ⁻ , and OR has the same meaning as OR that can be adopted as Y ⁶ , and the preferable ones are also the same. X ¹⁶ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), has the same meanings as those that can be adopted as X ⁷ , and the same is preferable, and an oxygen atom is particularly preferable.

The hole transport material represented by the above formula 5-2 has a group represented by the formula 1-a or an oxygen atom as X ² in the above formula 1-1, and is represented by the formula 1-c as Y ^1. It is a further preferred embodiment having a group
A ⁹ represents a heterocycle in which two or more rings are condensed, and has the same meaning as the heterocycle that can be adopted as A ⁴ , and the preferred ones are also the same.
V ² represents NR ^N4 . R ^N4 represents a hydrogen atom or a substituent, and is preferably a hydrogen atom (V ² is NH). The substituent that can be adopted as R ^N4 is not particularly limited, and is, for example, selected from the substituent group T described later, and is preferably an alkyl group.
Z ² represents CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5 , and has the same meaning as Z ¹ above, and the preferred ones are also the same.
R ^{25 to} R ²⁸ each represent a hydrogen atom or a substituent. The substituent that can be used is not particularly limited and is selected from, for example, the substituent group T described later. At least one of R ^{25 to} R ²⁸ is preferably an electron-withdrawing group, and more preferably 1 to 2 is an electron-withdrawing group.
R ²⁹ represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. R ²⁹ has the same meaning as R ¹² , and the preferred ones are also the same.
Y ¹⁴ represents OR or O ⁻ , and OR has the same meaning as OR that can be adopted as Y ⁷ , and the preferable ones are also the same. X ¹⁷ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), and has the same meaning as that which can be adopted as X ¹⁰ , and the preferable ones are also the same, with an oxygen atom being particularly preferable.

The hole transporting material represented by the above formula 5-3 has a group represented by the formula 1-b as X ² in the above formula 1-1, and a group represented by the formula 1-c as Y ^1. It is one more preferable embodiment having.
V ³ represents NR ^N4 , which has the same meaning as V ² described above, and the preferred ones are also the same.
V ⁴ represents N ⁺ R ^N3 or a nitrogen atom, has the same meaning as V ¹ above, and the preferred ones are also the same.
Z ³ and Z ⁴ each represent CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5 , which has the same meaning as Z ¹ above, and the preferred ones are also the same. One of Z ³ and Z ⁴ is preferably an oxygen atom or a sulfur atom, and more preferably Z ³ and Z ⁴ are different.

R ^{30 to} R ³⁹ each represent a hydrogen atom or a substituent, and other than R ³⁷ and R ³⁸ , especially R ³⁴ and R ³⁵ are preferably hydrogen atoms. The substituent that can be adopted is not particularly limited and is, for example, a group selected from the substituent group T described later, and is preferably a group other than the acidic group. More preferably, at least one of R ^{30 to} R ³³ , or at least one of R ^{36 to} R ³⁹ is an electron-withdrawing group, and even more preferably at least one of R ^{30 to} R ³³ and R ^{36 to} R ^39. And at least one of them is an electron-withdrawing group. In each of the set of R ^{30 to} R ^{33 and} the set of R ^{36 to} R ³⁹ , the number of electron withdrawing groups may be 1 or more, and preferably 1 or 2. The electron-withdrawing group is preferably a halogen atom.
When R ³⁷ and R ³⁸ take a substituent, they include a mode in which they are bonded to each other to form a ring, and a mode in which they are not bonded to each other and do not form a ring. In the embodiment in which R ³⁷ and R ³⁸ form a ring, the ring formed is not particularly limited, and may be a hydrocarbon ring or a hetero ring, and may be a substituent (for example, selected from the substituent group T described below). You may have two or more groups. Examples of such a ring include a ring capable of forming a hole-transporting material represented by Formula 6-1 described later, and more specifically, a partial structure of Formula 6-1 (Z ⁸ and V And a ring consisting of a heterocycle containing ⁸ and a group having Z ⁷ and V ⁷ as a bonding portion.

Y ¹⁵ represents OR or O ⁻ , and OR has the same meaning as OR that can be adopted as Y ⁸ , and the preferable ones are also the same. X ¹⁸ represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), has the same meanings as those that can be adopted as X ¹¹ , and the same is preferable, and an oxygen atom is particularly preferable.

The hole transporting material contained in the hole transporting layer 3 is also one of the more preferred embodiments, represented by the following formula 6-1.

The hole transport material represented by Formula 6-1 is one of the preferable embodiments of the hole transport material represented by Formula 5-3 above.
That is, in the hole transport material represented by the above formula 5-3, the substituents taken as R ³⁷ and R ³⁸ form a ring with each other, and the substituent taken as R ³⁷ and R ³⁸ are the above formulas. It is a form that forms a specific ring containing Z ⁷ and V ⁷ represented by 6-1. In this embodiment, the left side portion (partial structure from the heterocycle containing Z ⁵ and V ⁵ to the benzene ring having R ⁴⁶ and R ⁴⁷ ) of the hole transport material represented by formula 6-1 is represented by the above formula 5- Equivalent to 3.
Further, this hole-transporting material can also be referred to as a dimer in which the hole-transporting material represented by the above formula 5-3 shares a benzene ring in the heterocycle containing V ⁴ and Z ⁴ .

In the formula, V ⁵ and V ⁸ each represent NR ^N4 , which has the same meaning as V ³ above, and the preferred ones are also the same. Both V ⁵ and V ⁸ are preferably NH. V ⁶ and V ⁷ each represent N ⁺ R ^N3 or a nitrogen atom, and have the same meaning as V ⁴ , and the preferable ones are also the same.
Z ^{5 to} Z ⁸ each represent CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5 , which has the same meaning as Z ³ above, and the preferred ones are also the same. At least one of Z ^{5 to} Z ⁸ is preferably an oxygen atom or a sulfur atom, and more preferably two are oxygen atoms or a sulfur atom. Z that takes an oxygen atom or a sulfur atom is not particularly limited, and examples thereof include Z ^{6 and} Z ⁷ .
X ¹⁹ and X ²⁰ each represent an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), have the same meanings as those that can be adopted as X ¹⁸ , and the same is preferable, and an oxygen atom is particularly preferable. .
Y ¹⁶ and Y ¹⁷ each represent OR or O ⁻ , and OR has the same meaning as OR that can be adopted as Y ¹⁵ , and the preferable ones are also the same.
R ^{40 to} R ⁵³ each represent a hydrogen atom or a substituent. The substituent that can be used is not particularly limited and is selected from, for example, the substituent group T described later. Preferably, at least one of R ^{40 to} R ⁴³ or at least one of R ^{50 to} R ⁵³ is an electron-withdrawing group, and more preferably at least one of R ^{40 to} R ⁴³ and at least one of R ^{50 to} R ⁵³ . One is an electron-withdrawing group. In each of the group of R ^{40 to} R ^{43 and} the group of R ^{50 to} R ⁵³ , the number of electron-withdrawing groups may be 1 or more, and preferably 1 to 2. Each of R ⁴⁴ , R ^45, R ⁴⁸ and R ⁴⁹ is preferably a hydrogen atom. Each of R ⁴⁶ and R ⁴⁷ is more preferably a hydrogen atom or an aromatic heterocycle.

The hole transport material represented by the above formula 1-1 is also one of the preferable embodiments represented by the following formula 11-1 or formula 11-2.

The hole transport material represented by Formula 11-1 is one of the preferable embodiments of the hole transport material represented by Formula 5-2 above. The hole transport material represented by Formula 11-1 is the hole transport material represented by Formula 5-2 above, except that Z ² is an oxygen atom or a sulfur atom, and V ² is NH. Is synonymous with the hole transport material represented by the above formula 5-2.
That is, in Formula 11-1, Z ^a represents an oxygen atom or a sulfur atom, and an oxygen atom is preferable. Y ^a represents OR or O ⁻ , and has the same meaning as Y ¹⁴ described above, and the preferable ones are also the same. X ^b represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), has the same meanings as those that can be adopted as X ¹⁷ , and the same is preferable, and an oxygen atom is particularly preferable. X ^c represents a heterocycle in which two or more rings are condensed, has the same meaning as A ⁹ above, and the preferred ones are also the same.
R ^{a to} R ^e each represent a hydrogen atom or a substituent other than an acidic group, and a hydrogen atom is preferable. Substituents that can be taken may be groups other than the above acidic groups, and are selected from, for example, the substituent group T described later. At least one of R ^{a to} R ^d is preferably an electron-withdrawing group, and more preferably 1 to 2 is an electron-withdrawing group. The electron-withdrawing group is preferably a halogen atom.

The hole transport material represented by Formula 11-2 is one of the preferable embodiments of the hole transport material represented by Formula 5-3 above. The hole transport material represented by Formula 11-2 is the positive hole transport material represented by Formula 5-2 above except that V ³ is NH in the hole transport material represented by Formula 5-3. Synonymous with pore transport material.
V ^a1 represents N ⁺ R ^Nv or a nitrogen atom and has the same ^meaning as V ⁴ . R ^Nv represents a hydrogen atom or a substituent. The substituent that can be adopted as R ^Nv is not particularly limited, and is, for example, selected from the substituent group T described later, and is preferably an alkyl group.
Z ^b and Z ^c represent CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5 , and have the same ^meanings as Z ³ and Z ⁴ , respectively, and the preferred ones are also the same. At least one of Z ^b and Z ^c is an oxygen atom or a sulfur atom, and more preferably an oxygen atom. It is also preferable that Z ^b and Z ^c are different atoms or groups from each other. In this case, the combination of Z ^b and Z ^c is not particularly limited, and for example, a combination in which one of Z ^b and Z ^c is an oxygen atom or a sulfur atom and the other is CR ^C1 R ^C2 is preferable.
Y ^b represents OR or O ⁻ , has the same meaning as Y ¹⁵ described above, and the preferred ones are also the same. X ^d represents an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), has the same meanings as those that can be adopted as X ¹⁸ , and the same is preferable, and an oxygen atom is particularly preferable.

R ^{f to} R ^o each represent a hydrogen atom or a substituent other than an acidic group, and a hydrogen atom is preferable except R ^m and R ⁿ . Substituents that can be taken may be groups other than the above acidic groups, and are selected from, for example, the substituent group T described later. At least one of R ^{f to} R ⁱ or at least one of R ^{1 to} R ^o is preferably an electron-withdrawing group, and more preferably at least one of R ^{f to} R ⁱ and R ^{1 to} R ^o . At least one is an electron-withdrawing group. In each of the set of R ^{f to} R ^{i and} the set of R ^{1 to} R ^o , the number of electron-withdrawing groups may be 1 or more, and preferably 1 to 2. The electron-withdrawing group is preferably a halogen atom.
When R ^m and R ⁿ take a substituent, they include a mode in which they are bonded to each other to form a ring, and a mode in which they are not bonded to each other and do not form a ring. In the embodiment where R ^m and R ⁿ form a ring, the ring formed is not particularly limited, and may be a hydrocarbon ring or a hetero ring, and may be a substituent (for example, selected from the substituent group T described later). You may have two or more groups. Examples of such a ring include a ring capable of forming a hole-transporting layer represented by Formula 11-3 described later, and examples thereof include a partial structure of Formula 11-3 (hetero containing Z ^g and V ^d. And a ring consisting of a group having Z ^f and V ^c as a bonding part).

The hole transport material represented by Formula 1-1 is also one of the preferable embodiments represented by Formula 11-3 below.

This hole-transporting material is characterized in that V ^a and V ^d each can take NR ^N4 , and R ¹ and R ^m are specific substituents containing Z ^f and V ^c represented by the above formula 11-3. It has the same meaning as the hole-transporting material represented by the above formula 11-2, except that In this case, the left side portion (partial structure from the hetero ring containing Z ^d and V ^a to the benzene ring containing R ^u and R ^v ) of the hole transport material represented by Formula 11-3 is ^a point of V ^a . It is equivalent to the above formula 11-2 except for.
In addition, this hole transport material can also be referred to as a dimer in which the hole transport material represented by the above formula 11-2 shares a benzene ring in a hetero ring containing V ^b and Z ^e .

In the formula, V ^a and V ^d each represent NR ^N4 , which has the same meaning as V ³ , and the preferred ones are also the same. Each of V ^a and V ^d is preferably NH. V ^b and V ^c each represent N ⁺ R ^N3 or a nitrogen atom, and have the same meaning as V ⁴ above, and the preferred ones are also the same. Z ^{d to} Z ^g each represent CR ^C1 R ^C2 , an oxygen atom, a sulfur atom or NR ^N5 , which has the same meaning as Z ^b described above, and the preferred ones are also the same.
In Formula 11-3, at least one of V ^a and V ^d is NH, or at least one of Z ^{d to} Z ^g is an oxygen atom or a sulfur atom.
A preferable form of Z ^{d to} Z ^g is that both Z ^d and Z ^e , or both Z ^f and Z ^g are oxygen atoms or sulfur atoms. Furthermore, it is preferable that Z ^d and Z ^e , or Z ^f and Z ^g are different atoms or groups. In this case, the combination of Z ^d and Z ^e is not particularly limited, and for example, it is preferable that one of Z ^d and Z ^e is an oxygen atom or a sulfur atom and the other is CR ^C1 R ^C2 . The combinations of the Z ^d and ^{Z e,} is synonymous with combination of ^{Z d} and ^{Z e,} a preferred also the same.

Y ^c and Y ^d each represent OR or O ⁻ , have the same meaning as Y ^b , and the preferable ones are also the same. X ^e and X ^f each represent an oxygen atom, a sulfur atom, or ═C (G ¹ ) (G ² ), have the same meaning as X ^d , and the preferable ones are also the same, and the oxygen atom is particularly preferable.
R ^{p to} R ^z and R ^{aa to} R ^ac each represent a hydrogen atom or a substituent other than an acidic group, and a hydrogen atom is preferable. Substituents that can be taken may be groups other than the above acidic groups, and are selected from, for example, the substituent group T described later. It is preferred that at least one of the at least one or ^R z ^{to R ac} of R ^p to R ^s is an electron withdrawing group, more preferably at least one of ^R p to R ^s, at least R z ^{to R ac} One is an electron-withdrawing group. In each of the set of R ^{p to} R ^{s and} the set of R ^{z to} R ^ac , the number of electron-withdrawing groups may be 1 or more, and preferably 1 to 2. The electron-withdrawing group is preferably a halogen atom. Each of R ^t , R ^u , R ^x and R ^y is preferably a hydrogen atom. Each of R ^v and R ^w is more preferably a hydrogen atom or an aromatic heterocycle.

  Hereinafter, specific examples of the hole transport material represented by Formula 1-1 or Formula 1-2 will be illustrated, but the present invention is not limited thereto. In the following specific examples, Me represents methyl.

  Specific examples of hole transport materials other than the compounds represented by the above formulas are shown below, but the present invention is not limited thereto.

<Substituent group T>
Alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 and further preferably 1 to 6), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 and further preferably 1 to 6) ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 and further preferably 1 to 6), a cycloalkyl group (preferably having 3 to 20 carbon atoms, further preferably 3 to 6), cycloalkenyl. Group (preferably having 5 to 20 carbon atoms), aryl group (aromatic hydrocarbon ring group, preferably having 6 to 26 carbon atoms, more preferably 6 to 10), heterocyclic group (at least one oxygen atom as a ring-constituting atom) , A sulfur atom and a nitrogen atom, preferably having 2 to 20 carbon atoms, more preferably a 5-membered ring or a 6-membered ring, and the heterocyclic group includes an aromatic heterocyclic group (heteroaryl group) and an aliphatic group. A telocyclic group), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 and further preferably 1 to 6), an alkenyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2). To 12), an alkynyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12), a cycloalkyloxy group (preferably having 3 to 20 carbon atoms, further preferably 3 to 6), an aryloxy group (preferably Is a carbon number of 6 to 26), a heterocyclic oxy group (preferably a carbon number of 2 to 20),

Alkoxycarbonyl group (preferably C2-20), cycloalkoxycarbonyl group (preferably C4-20), aryloxycarbonyl group (preferably C6-20), heterocyclic oxycarbonyl group (preferably carbon) Formula 3 to 20), amino group (excluding unsubstituted amino group, preferably 1 to 20 carbon atoms, alkylamino group, alkenylamino group, alkynylamino group, cycloalkylamino group, cycloalkenylamino group, arylamino group) , A heterocyclic amino group), a sulfamoyl group (preferably having 0 to 20 carbon atoms, preferably an alkyl, cycloalkyl or aryl sulfamoyl group), an acyl group (preferably having 1 to 20 carbon atoms), an acyloxy group (preferably Is a carbon number of 1 to 20), a carbamoyl group (preferably a carbon number In 20, alkyl, a carbamoyl group of the cycloalkyl or aryl Preferably, for example, N, N- dimethylcarbamoyl, N- cyclohexylcarbamoyl or N- phenylcarbamoyl),

Acylamino group (preferably having 1 to 20 carbon atoms), sulfonamide group (preferably having 0 to 20 carbon atoms, preferably alkyl, cycloalkyl or aryl sulfonamide group), alkylthio group (preferably having 1 to 20 carbon atoms, More preferably 1 to 12, more preferably 1 to 6), a cycloalkylthio group (preferably having 3 to 20 carbon atoms, further preferably 31 to 6), an arylthio group (preferably having 6 to 26 carbon atoms, further preferably 6). -10), a heterocyclic thio group (preferably having 2 to 20 carbon atoms), an alkyl, cycloalkyl or arylsulfonyl group (preferably having 1 to 20 carbon atoms),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy and aryloxy), a silyloxy group (preferably having 1 to 20 carbon atoms, alkyl, aryl, alkoxy and aryloxy); Substituted silyloxy groups are preferred), hydroxy groups, cyano groups, nitro groups, oxo groups (═O), or halogen atoms (eg, fluorine atom, chlorine atom, bromine atom or iodine atom).

  More preferred groups selected from the substituent group T include alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, heterocyclic groups, alkoxy groups, cycloalkoxy groups, aryloxy groups, alkoxycarbonyl groups, cycloalkoxycarbonyl groups, Examples thereof include an amino group, an acylamino group, a cyano group or a halogen atom, or a group formed by combining a plurality of these groups.

In the present invention, the hole transport layer 3 preferably does not contain the dopant normally contained in the hole transport layer. The dopant is said to have a function of receiving a charge from the hole transport material, generating a free charge in the hole transport material, and improving the dielectric constant. As the dopant, for example, metal complexes, metal salts, organic compounds and the like, for example _{(p-BrC 6 H 4)} 3 NSbCl 6, trivalent cobalt complex (FK209 other), LiTFSI (lithiumbis (trifluoromethanesulfonyl) imide) , FeCl ₃ , WO ₃ , MoO _3, Molybdenum tris (1- (trifluoroacetyl) -2- (trifluoromethyl) ethane-1,2-dithiolene), SnCl ₄ , SbCl ₅ , F4-TCNQ, t-butylpyridine, etc. Has been.
However, when the manufacturing method of the present invention to be described later is applied, it is possible to further suppress variations in performance between devices when the hole transport layer does not contain a dopant. The reason for this is not clear, but when a hole transport layer liquid is applied by the manufacturing method of the present invention, if a dopant is present, it reacts with a component in the perovskite precursor film, which may cause any growth of the perovskite crystal. It is presumed to have an influence.
Here, "the hole transport layer does not contain a dopant" does not mean that even a form containing a small amount of a dopant is excluded within a range in which the effect of reducing the dopant is exhibited. That is, in the present invention, “the hole transport layer contains no dopant” means that the content of the dopant in the hole transport layer is 1% by mass or less.

  The thickness of the hole transport layer 3 is not particularly limited, but is preferably 50 μm or less, more preferably 1 nm to 10 μm, further preferably 5 nm to 5 μm, particularly preferably 10 nm to 1 μm. The thickness of the hole transport layer 3 corresponds to the average distance between the second electrode 2 and the surface of the photosensitive layer 13, and the cross section of the photoelectric conversion element should be observed using a scanning electron microscope (SEM) or the like. Can be measured.

<Second electrode 2>
The second electrode 2 functions as a positive electrode in the solar cell. The second electrode 2 is not particularly limited as long as it has electrical conductivity, and can usually have the same configuration as the electrically conductive support 11. The support 11a is not always necessary if the strength is sufficiently maintained.
As the structure of the second electrode 2, a structure having a high current collecting effect is preferable. At least one of the conductive support 11 and the second electrode 2 must be substantially transparent in order for light to reach the photosensitive layer 13. In the solar cell of the present invention, it is preferable that the conductive support 11 is transparent and sunlight or the like is incident from the support 11a side. In this case, it is more preferable that the second electrode 2 has a property of reflecting light.

Examples of the material forming the second electrode 2 include platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium ( Examples include metals such as Pd), rhodium (Rh), iridium (Ir), osmium (Os), and aluminum (Al), the above-mentioned conductive metal oxides, carbon materials, and conductive polymers. Any carbon material may be used as long as it is a material having carbon atoms bonded to each other and having conductivity, and examples thereof include fullerenes, carbon nanotubes, graphite and graphene.
As the second electrode 2, a thin film of a metal or a conductive metal oxide (including a thin film formed by vapor deposition), or a glass substrate or a plastic substrate having this thin film is preferable. As the glass substrate or the plastic substrate, glass having a gold or platinum thin film or platinum-deposited glass is preferable.

  The film thickness of the second electrode 2 is not particularly limited and is preferably 0.01 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 1 μm.

<Other configurations>
In the present invention, in order to prevent contact between the first electrode 1 and the second electrode 2, a spacer or a separator may be used instead of the blocking layer 14 or together with the blocking layer 14 or the like.
Further, a hole blocking layer may be provided between the second electrode 2 and the hole transport layer 3.

[Solar cell]
A solar cell can be manufactured using the photoelectric conversion element of the present invention. For example, as shown in FIGS. 1 to 4, the photoelectric conversion element 10 configured to work the external circuit 6 can be used as a solar cell. The external circuit 6 connected to the first electrode 1 (conductive support 11) and the second electrode 2 may be a known one without particular limitation.
The present invention is described in, for example, J. Am. Chem. Soc. , 2009, 131 (17), p. 6050-6051 and Science, 338, p. It can be applied to each solar cell described in 643 (2012).
The solar cell of the present invention is preferably sealed on the side surface with a polymer, an adhesive or the like in order to prevent the deterioration and evaporation of the constituents.

[Method for manufacturing photoelectric conversion element]
In the manufacturing method of the present invention, the hole transport layer is provided directly on the surface of the photosensitive layer. In the manufacturing method of the present invention, a unique process different from the conventional process is adopted in forming the photosensitive layer and the hole transport layer. Formation of layers (including the substrate) other than these layers is performed by a known manufacturing method, for example, J. Am. Chem. Soc. , 2009, 131 (17), p. 6050-6051, Science, 338, p. The method described in 643 (2012) or the like can be applied.
Below, the manufacturing method of the photoelectric conversion element of this invention is demonstrated.

In the production of the photoelectric conversion element of the present invention, first, at least one of the blocking layer 14, the porous layer 12, and the electron transport layer 15 is formed on the surface of the conductive support 11, if desired.
The blocking layer 14 can be formed by, for example, a method of applying a dispersion containing the above-mentioned insulating substance or its precursor compound or the like on the surface of the conductive support 11 and firing it, or a spray pyrolysis method.

The material forming the porous layer 12 is preferably used as fine particles, and more preferably used as a dispersion containing fine particles.
The method for forming the porous layer 12 is not particularly limited, and examples thereof include a wet method, a dry method, and other methods (for example, the method described in Chemical Review, 110, 6595 (2010)). To be In these methods, after the dispersion (paste) is applied to the surface of the conductive support 11 or the surface of the blocking layer 14, firing may be performed at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours, for example, in the air. preferable. This makes it possible to bring the fine particles into close contact with each other.
When firing is performed a plurality of times, it is preferable that the firing temperature other than the last firing (the firing temperature other than the last) is lower than the temperature of the last firing (the last firing temperature). For example, when a titanium oxide paste is used, the firing temperature other than the last can be set within the range of 50 to 300 ° C. Further, the final firing temperature can be set to be higher than the firing temperatures other than the last firing temperature within the range of 100 to 600 ° C. When a glass support is used as the support 11a, the firing temperature is preferably 60 to 500 ° C.

The coating amount of the porous material when forming the porous layer 12 is appropriately set according to the film thickness of the porous layer 12, the number of coatings, and the like, and is not particularly limited. For example, the coating amount of the porous material per 1 m ² of surface area of the conductive support 11 is preferably 0.5 to 500 g, more preferably 5 to 100 g.

  When the electron transport layer 15 is provided, it can be formed in the same manner as the hole transport layer 3 or the electron transport layer 4 described later.

Then, the photosensitive layer 13 and the hole transport layer 3 are provided.
To form the photosensitive layer 13, a coating liquid containing a precursor compound capable of forming a perovskite type crystal structure (a compound capable of synthesizing a perovskite compound; hereinafter also referred to as “perovskite precursor”) is used. In the present invention, the form of the "coating liquid" is not particularly limited, and may be any form such as solution, suspension, and paste, and is preferably a solution.
Examples of the perovskite precursor include compound AX represented by the above formula (ii) and compound MX ₂ represented by the above formula (iii).
One preferred embodiment of the manufacturing method of the present invention forms a coating film a using a coating solution a1 containing both compounds of the compound AX and MX _2. In another preferred embodiment, the coating liquid a2 containing the compound AX and the coating liquid a3 containing the compound MX ₂ are used to sequentially coat these coating liquids to form a coating film a. The coating liquids a1 to a3 are collectively referred to simply as the coating liquid a.

In the present invention, it is preferable to use the compound R ¹ —N (R ^1a ) ₃ X as the compound AX. Wherein, ^{R 1} and ^{R 1a} are each the same meaning as ^{R 1} and ^{R 1a} in the formula (I), and preferred forms are also the same. In the above compound, X is preferably a halogen atom.

The coating film a is formed by applying the coating liquid a. For example, a method of bringing the coating liquid a into contact with the surface of the layer that forms the photosensitive layer 13 on the surface (in the photoelectric conversion element 10, one of the porous layer 12, the blocking layer 14, and the electron transport layer 15) Can be adopted.
Examples of the coating method of the coating liquid a include spin coating, extrusion die coating, blade coating, bar coating, screen printing, stencil printing, roll coating, curtain coating, spray coating, dip coating, inkjet printing and dipping. A known coating method can be used. Among them, spin coating, screen printing, dipping method and the like are preferable.

After forming the coating film a, the coating film a may be dried to a certain extent, but the coating film a is not subjected to heat treatment. That is, the coating film a is not subjected to heat treatment until the coating liquid b containing the hole transport material described later is applied to the surface thereof. By applying a coating solution containing a hole transport material on the coating film a without subjecting it to heat treatment, the coating film a may have a positive hole before the perovskite type crystal structure is widely formed. The transport material can be contacted. As a result, the packing at the interface between the photosensitive layer and the hole transport layer is improved and the charge transfer becomes smooth, which is presumed to be one of the factors that can suppress the variation in the performance between the elements.
In the present invention, “the coating film a is not subjected to heat treatment” means that the coating film a is not exposed to a temperature of 50 ° C. or higher.
Further, it is preferable that the coating film a is not dried when the coating liquid b containing the hole transport material described later is applied. By applying the coating liquid b to the coating film a in an undried state, the interface between the photosensitive layer and the hole transport layer becomes easier to fit, and the variation in performance between devices can be further suppressed. Become. For the purpose of suppressing the drying of the coating film a before the application of the coating liquid b, for example, a solvent can be sprayed during or after the application of the coating liquid a.

The content of the perovskite precursor in the coating liquid a is preferably 1 to 95% by mass, more preferably 10 to 60% by mass. When AX and MX ₂ are used as the perovskite precursor, the molar ratio of AX and MX ₂ in the coating film a is preferably AX: MX ₂ = 10: 1 to 1: 2.
The medium used for the coating liquid a is preferably an organic solvent, and particularly preferably an alcohol solvent, an amide solvent, a sulfoxide solvent, a nitrile solvent, a hydrocarbon solvent, a lactone solvent, a halogen solvent or a mixture thereof.
In addition to the perovskite precursor and the medium, the coating liquid a may contain a light absorbing component such as a metal complex dye or an organic dye as long as the effect of the present invention is not impaired.

  In the manufacturing method of the present invention, the coating liquid b containing the hole transport material is applied onto the coating film a to form the coating film b. Examples of the method for forming the coating film b include known coating methods such as spin coating, extrusion die coating, blade coating, bar coating, screen printing, stencil printing, roll coating, curtain coating, spray coating, dip coating, and inkjet printing. Any method can be used. Of these, spin coating and screen printing are preferable.

  When one or more compounds represented by the formulas (H1), (H2-1), (H2-2), 1-1 and 1-2 are used as the hole transport material. Therefore, it is possible to more effectively suppress variations in performance between elements. The reason for this is not clear, but it is considered that this is because the affinity with the perovskite precursor or the perovskite compound is high and the packing effect is improved.

The content of the hole transport material in the coating liquid b is preferably 0.01 to 90% by mass, more preferably 0.1 to 50% by mass.
As the medium used for the coating liquid b, an organic solvent is preferable, and an alcohol solvent, an amide solvent, a sulfoxide solvent, a nitrile solvent, a hydrocarbon solvent, a lactone solvent, a halogen solvent, a solvent obtained by mixing these, or the like can be used. Halogen solvents are especially preferred.

  In the manufacturing method of the present invention, after the laminated structure of the coating film a and the coating film b is formed as described above, this laminated structure is subjected to heat treatment. By this heat treatment, the formation of the perovskite type crystal structure in the coating film a can be promoted while drying each layer. The temperature of this heat treatment is preferably 60 to 300 ° C, more preferably 70 to 170 ° C, and further preferably 90 to 150 ° C.

  By the method described above, the perovskite compound forms the photosensitive layer 13 on the surface of the porous layer 12, the blocking layer 14, or the electron transport layer 15, and the hole transport layer 3 is formed on the surface of the photosensitive layer 13.

  The photoelectric conversion element can be obtained by forming the second electrode 2 after forming the hole transport layer 3.

  The film thickness of each layer can be adjusted by appropriately changing the concentration of each dispersion or solution and the number of times of coating. For example, when the photosensitive layers 13B and 13C having a large film thickness are provided, the coating liquid a can be applied a plurality of times.

  The coating liquid and the like for forming each of the above-mentioned layers may contain additives such as a dispersion aid and a surfactant, if necessary.

  As the medium used in the method for manufacturing the photoelectric conversion element, those not specifically mentioned above may be, for example, the solvents described in JP 2001-291534 A. Among them, an organic solvent is preferable, and an alcohol solvent, an amide solvent, a nitrile solvent, a hydrocarbon solvent, a sulfoxide solvent, a lactone solvent, a halogen solvent, or a mixed solvent of two or more thereof is preferable. As the mixed solvent, a mixed solvent of an alcohol solvent and a solvent selected from an amide solvent, a sulfoxide solvent, a nitrile solvent or a hydrocarbon solvent is preferable. Specifically, methanol, ethanol, isopropanol, γ-butyrolactone, chlorobenzene, acetonitrile, N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), dimethylacetamide, or a mixed solvent thereof is preferable.

  The coating method for forming each layer is spin coating, extrusion die coating, blade coating, bar coating, screen printing, stencil printing, roll coating, curtain coating, spray coating, dip for those not particularly mentioned above. Known coating methods such as coating, inkjet printing and dipping can be used. Of these, spin coating and screen printing are preferred.

  The photoelectric conversion element of the present invention may be subjected to efficiency stabilization treatment such as annealing, light soaking, and leaving in an oxygen atmosphere, if necessary.

  The photoelectric conversion element manufactured as described above can be used as a solar cell by connecting the external circuit 6 to the first electrode 1 and the second electrode 2.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these modes.

  The photoelectric conversion element 10A shown in FIG. 1 was manufactured by the procedure shown below. When the film thickness of the photosensitive layer 13 is large, it corresponds to the photoelectric conversion element 10B shown in FIG.

[Example 1, Comparative Example 1] Production of photoelectric conversion element-1
<Production of conductive support 11>
A fluorine-doped SnO ₂ conductive film (transparent electrode 11b, film thickness 300 nm) was formed on a glass substrate (support 11a, thickness 2 mm) to prepare a conductive support 11.

<Preparation of solution for blocking layer>
A 15 mass% isopropanol solution of titanium diisopropoxide bis (acetylacetonate) (manufactured by Aldrich) was diluted with 1-butanol to prepare a 0.02M blocking layer solution.

<Formation of blocking layer 14>
A blocking layer 14 (thickness: 50 nm) made of titanium oxide is formed on the SnO ₂ conductive film of the conductive support 11 at 450 ° C. by a spray pyrolysis method using the prepared 0.02 M blocking layer solution. did.

<Preparation of titanium oxide paste>
Ethyl cellulose, lauric acid and terpineol were added to an ethanol dispersion of titanium oxide (anatase, average particle size 20 nm) to prepare a titanium oxide paste.

<Formation of Porous Layer 12>
The prepared titanium oxide paste was applied onto the blocking layer 14 by a spin coating method, and baked in air at 500 ° C. for 3 hours. After that, the obtained fired body of titanium oxide was immersed in a 40 mM TiCl ₄ aqueous solution, and then heated at 60 ° C. for 1 hour, and subsequently heated at 500 ° C. for 30 minutes to form a porous layer 12 of TiO ₂ ( A film thickness of 250 nm) was formed.

<Preparation of coating liquid a>
A 40% methanol solution of methylamine (27.86 mL) and an aqueous solution of 57 mass% hydrogen iodide (hydroiodic acid, 30 mL) were stirred in a flask at 0 ° C. for 2 hours and then concentrated to give CH ₃ NH _3. A crude product of ₃ I was obtained. The obtained CH ₃ NH ₃ I crude product was dissolved in ethanol and recrystallized with diethyl ether, and the obtained crystals were collected by filtration and dried under reduced pressure at 60 ° C. for 5 hours to obtain purified CH ₃ NH ₃ I. Obtained.
Then, purified CH ₃ NH ₃ I and PbI ₂ were stirred and mixed in DMF at a molar ratio of 3: 1 at 60 ° C. for 12 hours, and then filtered through a polytetrafluoroethylene (PTFE) syringe filter to obtain a perovskite precursor. A coating liquid a containing 40% by mass was prepared.

<Preparation of coating liquid b>
The hole-transporting layer shown in the table below (20 mg, 180 mg only for S1 (spiro-OMeTAD)) was dissolved in chloroform (1 mL) and then filtered with a polytetrafluoroethylene (PTFE) syringe filter to form a hole-transporting layer. A coating solution b, which is a forming solution, was prepared.
In addition, the reference numerals described in the column of the hole transport material in the table below correspond to the reference numerals given to the exemplified compounds described above.

<Formation of Photosensitive Layer and Hole Transport Layer by Conventional Process (Comparative Example)>
On the porous layer 12 formed on the conductive support 11, the coating liquid a was formed by spin coating (5000 rpm for 60 seconds). During this spin coating, 500 μL of toluene was sprayed onto the surface of the coating layer with a pipettor during rotation. It was dried at 100 ° C. for 60 minutes on a hot plate to provide a photosensitive layer 13A (film thickness 250 nm) having a perovskite type crystal structure of CH ₃ NH ₃ PbI ₃ . Thus, the first electrode 1A was produced.
Next, the coating liquid b was applied onto the photosensitive layer 13A by a spin coating method (5000 rpm for 30 seconds) and dried to form a solid hole transport layer 3A.

<Formation of Photosensitive Layer and Hole Transport Layer by Process Defined in the Present Invention (Example)>
The coating liquid a was formed on the porous layer 12 formed on the conductive support 11 by a spin coating method (5000 rpm for 60 seconds) to form a coating film a. During this spin coating, 500 μL of toluene was sprayed onto the surface of the coating layer with a pipettor during rotation.
Next, the coating liquid b was applied to the undried coating film a by a spin coating method (5000 rpm for 30 seconds) to form a coating film b. The laminated body containing the coating film a and the coating film b thus formed was subjected to heat treatment at 100 ° C. for 60 minutes using a hot plate and dried, and the coating film a had a perovskite type crystal of CH ₃ NH ₃ PbI _3. The structure was formed. Thus, the photosensitive layer 13A (film thickness 250 nm) and the hole transport layer 3A (film thickness 50 nm) having the perovskite type crystal structure were formed to obtain a laminate having the hole transport layer 3A on the first electrode 1A.

<Formation of hole injection layer>
MoO ₃ was deposited on the hole transport layer 3A by a vapor deposition method to form a hole injection layer (film thickness 10 nm).

<Production of second electrode 2>
Gold was vapor-deposited on the hole injection layer by a vapor deposition method to form the second electrode 2 (film thickness 100 nm).
Thus, the photoelectric conversion element 10A was manufactured.
The film thickness of each layer was observed and measured by SEM according to the above method.

[Example 2 and Comparative Example 2] Production of photoelectric conversion element-2
Photoelectric conversion elements shown in the following table were produced in the same manner as in "Production of photoelectric conversion element-1" described above except that the coating liquid b was prepared as follows.

<Preparation of coating liquid b>
A hole-transporting material shown in the table below (20 mg, 180 mg only for S1 (spiro-OMeTAD)), 37.5 μL of an acetonitrile solution in which lithium-bis (trifluoromethanesulfonyl) imide (170 mg) was dissolved in acetonitrile (1 mL), t-Butylpyridine (TBP, 17.5 μL) was dissolved in chloroform (1 mL), and then filtered with a polytetrafluoroethylene (PTFE) syringe filter to prepare a coating liquid b (containing dopant).

[Example 3 and Comparative Example 3] Production of photoelectric conversion element-3
The above-mentioned "Production of photoelectric conversion element-1" except that the coating solution a was prepared as follows and the formation of the photosensitive layer and the hole transport layer (Comparative Examples and Examples) was performed as follows. The photoelectric conversion elements shown in the table below were produced in the same manner as in ".

<Preparation of coating liquid a>
Cesium iodide (39 mg), formamidine hydroiodide (516 mg), CH ₃ NH ₃ Br (67 mg) and lead iodide (1.73 g) were mixed with DMF and DMSO (dimethyl sulfoxide). A coating liquid a was prepared by dissolving in a solvent (DMF / DMSO = 4/1 (volume ratio)).

<Formation of Photosensitive Layer and Hole Transport Layer by Conventional Process (Comparative Example)>
The coating liquid a was applied onto the porous layer 12 formed on the conductive support 11 by a spin coating method (5000 rpm for 50 seconds). During this spin coating, 500 μL of chlorobenzene was sprayed onto the surface of the coating layer with a pipettor while rotating. The photosensitive layer 13A having a perovskite type crystal structure of Cs _0.04 FA _0.8 (CH ₃ NH ₃ ) _0.16 PbI _2.84 Br _{0.16 after} drying for 60 minutes at 100 ° C. on a hot plate (thickness 300 nm (Including the film thickness of 250 nm of the porous layer 12)) was formed. Thus, the first electrode 1A was produced.
Incidentally, "FA" represents a formamidinium _{(HC (= NH) NH 3} ).
Next, the coating liquid b was applied on the photosensitive layer 13A by a spin coating method (5000 rpm for 30 seconds) and dried to form a solid hole transport layer 3A.

<Formation of Photosensitive Layer and Hole Transport Layer by Process Defined in the Present Invention (Example)>
The coating liquid a was applied onto the porous layer 12 formed on the conductive support 11 by a spin coating method (5000 rpm for 50 seconds) to form a coating film a. During this spin coating, 500 μL of chlorobenzene was sprayed onto the surface of the coating layer with a pipettor while rotating.
Next, the coating liquid b was applied to the undried coating film a by a spin coating method (5000 rpm for 30 seconds) to form a coating film b. The laminated body containing the coating film a and the coating film b thus formed was subjected to heat treatment at 100 ° C. for 60 minutes using a hot plate and dried, and the coating film a was coated with Cs _0.04 FA _0.8 (CH A perovskite type crystal structure of ₃ NH ₃ ) _0.16 PbI _2.84 Br _0.16 was formed. Thus, the photosensitive layer 13A (film thickness 250 nm) and the hole transport layer 3A (film thickness 50 nm) having the perovskite type crystal structure were formed to obtain a laminate having the hole transport layer 3A on the first electrode 1A.

[Example 4, Comparative Example 4] Production of photoelectric conversion element-4
Photoelectric conversion elements shown in the following table were produced in the same manner as in "Production of photoelectric conversion element-1" described above except that the hole injection layer was not provided.
In addition, about the example which used S1 as a hole transport material, the dopant was used together similarly to the above-mentioned "Production of photoelectric conversion element-2."

[Test Example] Evaluation of Variation in Photoelectric Conversion Efficiency In each of the above Examples and Comparative Examples, nine photoelectric conversion elements were manufactured by the same manufacturing method. A battery characteristic test was conducted on 9 samples of photoelectric conversion elements obtained by the same manufacturing method, and the photoelectric conversion efficiency (η /%) of each of the 9 samples was obtained. The battery characteristic test was performed by irradiating each sample with 1000 W / m ² of pseudo sunlight from a xenon lamp that passed an AM1.5 filter using a solar simulator “PEC-L15” (manufactured by Pexel Technologies). went. The photoelectric conversion efficiency was obtained by measuring the current-voltage characteristics of each photoelectric conversion element irradiated with pseudo sunlight using a source meter “Keithley 2401” (manufactured by Tektronix).
Among the 9 samples of photoelectric conversion elements obtained by the same manufacturing method, the average value (η _av ) of the photoelectric conversion efficiencies of 7 samples excluding 1 sample having the highest photoelectric conversion efficiency and 1 sample having the lowest photoelectric conversion efficiency was calculated. I asked. The average value (η _av ) of the photoelectric conversion efficiency is set to 1 (reference), and the relative value (η _in / η _av = η) of the photoelectric conversion efficiency (η _in ) of each of the 7 specimens with respect to the average value (η _av ). _re ) was calculated, and the relative value at which the absolute value of the difference from the reference value 1 (| 1-η _re |) was the largest was defined as “mη _re ”.
For the same coating liquid a and the same coating liquid b, the respective m η _re of the device (Example) obtained by the process of the present invention and the device (Comparative example) obtained by the conventional process were compared (see "N-m [eta] _re " is obtained by the above process and "o-m [eta] _re " is obtained by the conventional process.), And the variation in photoelectric conversion efficiency between the devices is evaluated based on the following evaluation criteria.

<Evaluation criteria>
A: (o-m [eta] _re )-(n-m [eta] _re ) ≥0.1
B: 0.1> (o-m [eta] _re )-(n-m [eta] _re ) ≥0.08
C: 0.08> (o-m η _re )-(n-m η _re ) ≧ 0.07
D +: 0.07> (o-m [eta] _re )-(n-m [eta] _re ) ≥0.06
D: 0.06> (o-m [eta] _re )-(n-m [eta] _re ) ≥0.04
E: 0.04> (o-mη re) - (n-mη re) ≧ 0.02
F: 0.02> (o-m [eta] _re )-(n-m [eta] _re )> 0.00
G: 0.00 ≧ (o-m η _re )-(n-m η _re ).
The results are shown in the table below.

  As shown in the above tables, each of the photoelectric conversion elements in which the photosensitive layer and the hole transport layer were formed by the method specified in the present invention was a photoelectric conversion element in which the photosensitive layer and the hole transport layer were formed by the conventional method ( It can be seen that the variation in photoelectric conversion efficiency between the obtained devices can be suppressed as compared with the method of applying the method of providing the hole transport layer after providing the photosensitive layer on which the perovskite type crystal structure is formed).

1A to 1D First electrode 11 Conductive support 11a Support 11b Transparent electrode 12 Porous layer 13A to 13C Photosensitive layer 14 Blocking layer 2 Second electrode 3A, 3B Hole transport layer 15 Electron transport layer 6 External circuit (lead)
10A-10D Photoelectric conversion element 100A-100F System M using a solar cell Electric motor

Claims (10)

Photoelectric conversion element having a first electrode having a conductive support and a photosensitive layer, a hole transport layer provided in contact with the photosensitive layer, and a second electrode provided on the hole transport layer. The manufacturing method of
Forming a coating film a by applying a coating liquid a containing a precursor compound capable of forming a perovskite type crystal structure on the conductive support;
Forming a coating film b by applying a coating liquid b containing a hole transport material on the coating film a without subjecting the coating film a to heat treatment;
And subjecting the formed laminated structure of the coating film a and the coating film b to heat treatment to form a perovskite type crystal structure in the coating film a. The method for producing a photoelectric conversion element according to claim 1, wherein the hole transport material contains a compound represented by the following formula (H1).
_{^{A 1 - (L 1) nb}} - (D 1) na - (L 2) nc -A 2 Formula (H1)
In the formula, A ¹ and A ² represent a heterocyclic group, a hydrocarbon ring group or an acceptor group.
L ¹ and L ² represent a linking group, and nb and nc are integers of 0-5.
D ¹ represents a condensed ring structure, and na is an integer of 1 to 4. Wherein ^{D 1} is represented by the following formula ^(D 1 -1) or ^(D 1 -2), a method for manufacturing a photoelectric conversion element according to claim 2, wherein.

X ^{1 to} X ⁴ represent a sulfur atom, an oxygen atom or a selenium atom.
Z ^{1 to} Z ⁴ represent a nitrogen atom or CR ^a , and R ^a represents a hydrogen atom or a substituent.
A and B show a ring structure.
* Indicates a connection site. The method for producing a photoelectric conversion element according to claim 1, wherein the hole transport material contains a compound represented by the following formula (H2-1) or (H2-2).
_{^{D 2 - (L 3) nd}} -C (R 1) = A 3 Equation (H2-1)
_{^{D 2 = (L 3) nd}} -C (R 1) = A 3 Equation (H2-2)
In the formula, D ² represents a donor group.
L ³ represents a linking group, and nd represents an integer of 0 to 5.
R ¹ represents a hydrogen atom or a substituent.
A ³ represents an acceptor group. The method for producing a photoelectric conversion element according to claim 4, wherein the D ² includes a condensed ring structure composed of 3 or more rings. 6. The compound represented by the formula (H2-1) is represented by the following formula (H2-1-1), (H2-1-2) or (H2-1-3), and the compound according to claim 4 or 5. Manufacturing method of photoelectric conversion element.

In the formula, E represents a ring structure.
G represents a heterocyclic structure containing a nitrogen atom as a ring-constituting atom.
R < ² > -R < ⁴ > shows a substituent, ne is an integer of 0-4, nf is an integer of 0-3, nh is an integer of 0-5, and ng is 0 or 1.
L ³ and A ³ have the same meanings as L ³ and A ^{3 in} formula (H2-1), respectively. The method for producing a photoelectric conversion element according to claim 1, wherein the hole transport material contains a compound represented by the following formula 1-1 or 1-2.

In the formula, X ^{1 to} X ⁴ represent an oxygen atom, a sulfur atom, a group represented by the following formula 1-a, a group represented by the following formula 1-b, or = C (G ¹ ) (G ² ). . G ¹ and G ² represent an electron-withdrawing group and are not linked to each other to form a ring.
Y ^{1 to} Y ⁴ represent OR, SR, O ⁻ , S ⁻ , a halogen atom, a group represented by the following formula 1-c, or a group represented by the following 1-d. R represents a hydrogen atom or a substituent.

In the formula, A ¹ represents a hydrocarbon ring or a hetero ring, and B ¹ represents a hetero ring or NR ^N1 R ^N2 . R ^N1 and R ^N2 represent a substituent, and they are not linked to each other to form a ring.
L ^{1 to} L ⁴ represent a linking group. na and nd are integers of 0 to 2, and nb and nc are 1 or 2.
* Indicates a linking site with Formula 1-1 or Formula 1-2.
However, the compound represented by Formula 1-1 and the compound represented by Formula 1-2 have at least one group represented by any one of Formula 1-a to Formula 1-d, It does not have a COOH and -NH _2. The method for manufacturing a photoelectric conversion element according to claim 7, wherein the hole transport material is represented by any one of the following formulas 2-1 to 2-5.

In the formula, A ² represents a heterocycle. A ⁴ represents a heterocycle in which two or more rings are condensed or an oxygen atom. A ³ , A ⁵ , B ² and B ³ represent a heterocycle.
L ^{5 to} L ¹³ represent a linking group. ne to ng, ni and nj are integers of 0 to 2, and nh and nk to nm are 1 or 2.
X ^{6 to} X ¹¹ represent an oxygen atom, a sulfur atom or = C (G ¹ ) (G ² ). G ¹ and G ² represent an electron-withdrawing group and are not linked to each other to form a ring.
Y ^{5 to} Y ⁸ represent OR, SR, O ⁻ , S ⁻ or a halogen atom.
R ^{1 to} R ⁸ represent a substituent.   The method for manufacturing a photoelectric conversion element according to claim 1, wherein the coating liquid b containing the hole transport material does not contain a dopant. A method for manufacturing a solar cell, wherein a photoelectric conversion element is obtained by the method for manufacturing a photoelectric conversion element according to claim 1, and a solar cell is manufactured using the obtained photoelectric conversion element.