JP6379074B2 - Photoelectric conversion element and solar cell - Google Patents

Description

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

  Photoelectric conversion elements are used in various optical sensors, copying machines, solar cells, and the like. Solar cells are expected to be put into full-scale practical use as non-depleting solar energy. There are various types of solar cells such as silicon, dye sensitization, and organic thin film (see, for example, Patent Documents 1 to 3). Among them, dye sensitization using an organic dye or a Ru bipyridyl complex as a sensitizer. Research and development of active solar cells has been actively promoted, and the photoelectric conversion efficiency has reached about 11%.

  On the other hand, in recent years, solar cells using metal halides as compounds having a perovskite crystal structure (hereinafter also referred to as “perovskite compounds” or “perovskite light absorbers”) have a relatively high photoelectric conversion efficiency. Research results that can be achieved are reported and attracting attention.

For example, in Non-Patent Document 1, a perovskite compound represented by CH ₃ NH ₃ PbI _3-x Cl _x is used as a light absorber in a photosensitive layer, and a poly perovskite compound is used as a hole transport material in a hole transport layer. In a solar cell using (3-hexylthiophene-2,5-diyl) (poly (3-hexylthiophene); P3HT), it has been reported that the photoelectric conversion efficiency has reached 9.3%.

JP 2012-195575 A JP 2013-100457 A JP 2012-214681 A

Journal of Power Sources 251 (2014) p. 152-156.

  A photoelectric conversion element or a solar cell using a perovskite compound has achieved certain results in improving photoelectric conversion efficiency. However, photoelectric conversion elements or solar cells using perovskite compounds have attracted attention in recent years, and little is known about battery performance other than photoelectric conversion efficiency.

  In addition to high photoelectric conversion efficiency, the photoelectric conversion element and the solar cell are required to have durability capable of maintaining initial performance in the field environment where they are actually used.

  However, it is known that perovskite compounds are susceptible to damage in a high humidity environment or a high humidity heat environment. In fact, photoelectric conversion elements or solar cells using a perovskite compound as a light absorber often have a significant decrease in photoelectric conversion efficiency in a high humidity environment or a high humidity heat environment.

  It is an object of the present invention to provide a photoelectric conversion element using a perovskite compound as a light absorber in a photosensitive layer, which is excellent in moisture resistance and moist heat resistance. Moreover, this invention makes it a subject to provide the solar cell provided with the said photoelectric conversion element.

  In a photoelectric conversion element or a solar cell using a perovskite compound as a light absorber, the present inventors have used a polymer having a specific structural unit as a hole transport material in a hole transport layer, thereby providing a high humidity environment. It has been found that a photoelectric conversion element or a solar cell can be obtained in which the photoelectric conversion efficiency is not easily lowered even under a high humidity environment. The present invention has been further studied based on these findings and has been completed.

That is, the above-mentioned subject of the present invention was solved by the following means in one mode.
[1]
A first electrode comprising a conductive support, a photosensitive layer containing a light absorber provided on the conductive support, a second electrode facing the first electrode, a first electrode and a second electrode A photoelectric conversion element having a hole transport layer between and
The photosensitive layer has, as the light absorber, a cation of a group 1 element of the periodic table or a cationic organic group A, a cation of a metal atom M other than the group 1 element of the periodic table, and an anionic atom or an atomic group X. At least a compound having a perovskite crystal structure containing an anion,
The hole transport layer contains at least a polymer having a structural unit represented by the following formula (AI).

Where
Ar ¹ and Ar ² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.

-(-Z-) _n- represents a linking group necessary for forming a ring together with Ar ¹ and Ar ² linked to each other by a single bond. n represents 1 or 2, and when n is 1, the formed ring is a 5-membered ring, and when n is 2, the formed ring is a 6-membered ring. When n is 2, two Zs may be the same or different.

Z represents —O—, —S—, —C (═O) —, —CR ¹ R ² —, —S (═O) —, —SO ₂ —, —Si (R ³ ) (R ⁴ ) —. , -N (R ⁵ )-, -B (R ⁶ )-, -P (R ⁷ )-or -P (= O) (R ⁸ )-, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or a substituent.

* Represents a bonded portion with another site constituting the polymer.
[2]
The photoelectric conversion element according to [1], wherein the structural unit represented by the formula (AI) is represented by the following formula (AII).

Where
Ar ²¹ and Ar ²² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.

R ²¹ and R ²² each independently represents a hydrogen atom or a substituent. Alternatively, R ²¹ and R ²² may be connected to each other to form a ring.

* Represents a bonded portion with another site constituting the polymer.
[3]
The photoelectric conversion element according to [1], wherein the structural unit represented by the formula (AI) is represented by the following formula (AIII).

Where
Ar ³¹ and Ar ³² each independently represent a trivalent aromatic heterocyclic group.

R ³¹ , R ³² , R ³³ and R ³⁴ each independently represent a hydrogen atom or a substituent. Alternatively, two of R ³¹ , R ³² , R ³³ and R ³⁴ are connected to form a ring, and the rest each independently represents a hydrogen atom or a substituent.

* Represents a bonded portion with another site constituting the polymer.
[4]
In the formula (AI), at least one Z is —CR ¹ R ² —, and at least one of R ¹ and R ² is a group represented by the following formula (AIV), Conversion element.

Where
L ¹¹ represents a linking group, Ar ¹⁰ represents an aryl group or a heteroaryl group, and * represents a bond to the carbon atom to which R ¹ or R ² is bonded.
[5]
The photoelectric conversion element according to [2], wherein in formula (AII), at least one of R ²¹ and R ²² is a group represented by the following formula (AV).

Where
L ²¹ represents a linking group, Ar ²⁰ represents an aryl group or a heteroaryl group, and * represents a bond to the carbon atom to which R ²¹ or R ²² is bonded.
[6] The photoelectric conversion element according to [3], wherein in formula (AIII), at least one of R ³¹ , R ³² , R ³³ and R ³⁴ is a group represented by the following formula (AVI).

Where
L ³¹ represents a linking group, Ar ³⁰ represents an aryl group or a heteroaryl group, and * represents a bond to the carbon atom to which R ³¹ , R ³² , R ³³ or R ³⁴ is bonded.
[7]
The photoelectric conversion element according to [1] or [4], wherein in formula (AI), Ar ¹ and Ar ² are thiophene rings.
[8]
The photoelectric conversion element according to [1], [4], or [7], wherein n is 2 in the formula (AI).
[9]
In the formula (AII), the photoelectric conversion element according to [2] or [5], wherein Ar ²¹ and Ar ²² are thiophene rings.
[10]
The photoelectric conversion element according to [3] or [6], wherein in formula (AIII), Ar ³¹ and Ar ³² are thiophene rings.
[11]
The solar cell which comprises the photoelectric conversion element of any one of [1]-[10].

  In the present specification, a part of the notation of each formula may be expressed as a formula for understanding the chemical structure of the compound. Accordingly, in each formula, the partial structure is referred to as a (substituted) group, ion, atom, or the like. In this specification, these are represented by the above formula in addition to the (substituted) group, ion, atom, or the like. It may mean an element group or an element constituting a (substituted) group or ion.

  In this specification, about the display of a compound (a complex and a pigment | dye are included), it uses for the meaning containing its salt and its ion besides the compound itself. In addition, it means that a part of the structure is changed as long as the desired effect is achieved. Furthermore, a compound that does not clearly indicate substitution or non-substitution means that it may have an arbitrary substituent within a range that exhibits a desired effect. The same applies to substituents and linking groups (hereinafter referred to as substituents and the like).

  In this specification, when there are a plurality of substituents and the like indicated by a specific symbol, or when a plurality of substituents and the like are specified at the same time, the respective substituents are the same as or different from each other unless otherwise specified. May be. The same applies to the definition of the number of substituents and the like. Further, when a plurality of substituents and the like are close to each other (especially when they are adjacent to each other), they may be connected to each other to form a ring unless otherwise specified. In addition, a ring such as an alicyclic ring, an aromatic ring, or a heterocyclic ring may be further condensed to form a condensed ring.

  In addition, a numerical range expressed using “to” in this specification means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The photoelectric conversion element and the solar cell of the present invention are excellent in moisture resistance and moist heat resistance even though they include a perovskite compound as a light absorber.

FIG. 1A is a cross-sectional view schematically showing a preferred embodiment of the photoelectric conversion element of the present invention. FIG. 1B is an enlarged view of the cross-sectional area b of FIG. 1A. FIG. 2 is a cross-sectional view schematically showing another preferred embodiment of the photoelectric conversion element of the present invention. FIG. 3 is a cross-sectional view schematically showing another preferred embodiment of the photoelectric conversion element of the present invention. FIG. 4 is a cross-sectional view schematically showing still another preferred embodiment of the photoelectric conversion element of the present invention.

<< Photoelectric conversion element >>
The photoelectric conversion element of the present invention includes a first electrode having a conductive support and a photosensitive layer provided on the conductive support, a second electrode facing the first electrode, a first electrode and a second electrode. It has a hole transport layer in between.

  In the present invention, providing a photosensitive layer on a conductive support means an embodiment in which a photosensitive layer is provided (directly provided) in contact with the surface of the conductive support, and another layer is provided above the surface of the conductive support. It includes a mode in which a photosensitive layer is provided.

  In the embodiment having the photosensitive layer through another layer above the surface of the conductive support, the other layer provided between the conductive support and the photosensitive layer does not deteriorate the battery performance of the solar cell. If there is no particular limitation. For example, a porous layer, a blocking layer, an electron transport layer, etc. are mentioned.

  In the present invention, as an aspect having a photosensitive layer through another layer above the surface of the conductive support, for example, an aspect in which the photosensitive layer is provided in the form of a thin film on the surface of the porous layer (FIGS. 1B), a mode (see FIG. 2) provided on the surface of the porous layer (see FIG. 2), a mode provided on the surface of the blocking layer as a thin or thick film (see FIG. 3), and an electron transport layer Examples include a mode in which a thin film or a thick film (see FIG. 4) is provided on the surface. The photosensitive layer may be provided in a linear or dispersed form, but is preferably provided in a film form.

  The photoelectric conversion element of the present invention is not particularly limited in structure other than the structure defined in the present invention, and a known structure 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 a single layer or multiple layers, for example. For example, a porous layer can be provided between the conductive support and the photosensitive layer (see FIGS. 1A and 2).

  Hereinafter, the preferable aspect of the photoelectric conversion element of this invention is demonstrated.

  1A, FIG. 1B, and FIGS. 2 to 4, the same reference numerals mean the same components (members).

  1A and 2 show the size of the fine particles forming the porous layer 12 with emphasis. These fine particles are preferably clogged (deposited or adhered) in the horizontal and vertical directions with respect to the conductive support 11 to form a porous structure.

  In the present specification, the term “photoelectric conversion element 10” means the photoelectric conversion elements 10A to 10D unless otherwise specified. The same applies to the system 100 (hereinafter “system”) using the solar cell and the first electrode 1. Further, when the photosensitive layer 13 is simply referred to, 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 aspect of the photoelectric conversion element of the present invention, for example, a photoelectric conversion element 10A shown in FIG. 1A can be given. A system 100A shown in FIG. 1A is a system applied to a battery for causing the operation means M (for example, an electric motor) to work with the external circuit 6 using the photoelectric conversion element 10A.

  The photoelectric conversion element 10A includes a first electrode 1A, a second electrode 2, and a hole transport layer 3A.

  1 A of 1st electrodes are porous as typically shown by FIG. 1B which expanded the electroconductive support body 11 which consists of the support body 11a and the transparent electrode 11b, the porous layer 12, and the cross-sectional area | region b in FIG. 1A. The surface of the layer 12 has a photosensitive layer 13A provided with a perovskite light absorber. Further, the blocking layer 14 is provided on the transparent electrode 11 b, and the porous layer 12 is formed on the blocking layer 14. Thus, it is estimated that the photoelectric conversion element 10A having the porous layer 12 improves the charge separation and charge transfer efficiency because the surface area of the photosensitive layer 13A is increased.

  The photoelectric conversion element 10B shown in FIG. 2 schematically shows a preferred embodiment in which the photosensitive layer 13A of the photoelectric conversion element 10A shown in FIG. 1A is provided thick. In the photoelectric conversion element 10B, the hole transport layer 3B is thinly provided. The photoelectric conversion element 10B differs from the photoelectric conversion element 10A shown in FIG. 1A in the film thicknesses of the photosensitive layer 13B and the hole transport layer 3B, but is configured in the same manner as the photoelectric conversion element 10A except for these points. ing.

  A photoelectric conversion element 10 </ b> C shown in FIG. 3 schematically shows another preferred embodiment of the photoelectric conversion element of the present invention. The photoelectric conversion element 10C is different from the photoelectric conversion element 10B illustrated in FIG. 2 in that the porous layer 12 is not provided, but is configured in the same manner as the photoelectric conversion element 10B except for this point. That is, in the photoelectric conversion element 10 </ b> C, the photosensitive layer 13 </ b> C is formed in a thick film shape on the surface of the blocking layer 14. In the photoelectric conversion element 10 </ b> C, the hole transport layer 3 </ b> B can be provided thick like the hole transport layer 3 </ b> A illustrated in FIG. 1A.

  The photoelectric conversion element 10D shown in FIG. 4 schematically shows another preferred embodiment of the photoelectric conversion element 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 is otherwise configured in the same manner as the photoelectric conversion element 10C. Yes. The first electrode 1 </ b> D includes a conductive support 11 and an electron transport layer 15 and a photosensitive layer 13 </ b> C that 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. As a result, the productivity of the photoelectric conversion element is improved, and it is possible to make it thinner or 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, light that has passed through the conductive support 11 or passed through the second electrode 2 and entered the photosensitive layer 13 excites the light absorber. The excited light absorber has electrons with high energy and can emit these electrons. The light absorber that has released electrons with high energy becomes an oxidant.

  In the photoelectric conversion elements 10 </ b> A to 10 </ b> D, electrons emitted from the light absorber move between the light absorbers and reach the conductive support 11. After the electrons that have reached the conductive support 11 work in the external circuit 6, they return to the photosensitive layer 13 through the second electrode 2 and the hole transport layer 3. The light absorber is reduced by the electrons returning to the photosensitive layer 13.

  In the photoelectric conversion element 10, the system 100 functions as a solar cell by repeating such excitation and electron transfer cycles of the light absorber.

In the photoelectric conversion elements 10 </ b> A to 10 </ b> D, the way in which electrons flow from the photosensitive layer 13 to the conductive support 11 varies depending on the presence / absence of the porous layer 12 and the type thereof. In the photoelectric conversion element 10 of the present invention, electron conduction in which electrons move between the light absorbers occurs. Therefore, when providing the porous layer 12, the porous layer 12 can be formed with an insulator other than the conventional semiconductor. When the porous layer 12 is formed of a semiconductor, electron conduction in which electrons move inside the semiconductor fine particles of the porous layer 12 or between the semiconductor fine particles also occurs. On the other hand, when the porous layer 12 is formed of an insulator, electron conduction in the porous layer 12 does not occur. 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 ) particles as the insulator particles.

  When the blocking layer 14 as the other layer is formed of a conductor or a semiconductor, electron conduction in the blocking layer 14 occurs.

  Electron conduction also occurs in the electron transport layer 15.

  The photoelectric conversion element and the solar cell of the present invention are not limited to the above-described preferred embodiments, and the configuration of each embodiment can be appropriately combined between the respective embodiments without departing from the spirit of the present invention.

  In this invention, the material and each member which are used for a photoelectric conversion element or a solar cell can be prepared by a conventional method except the material and member prescribed | regulated by this invention. For example, for perovskite sensitized solar cells, see, for example, Non-Patent Document 1 and J. MoI Am. Chem. Soc. 2009, 131 (17), p. 6050-6051 and Science, 338, p. 643-647 (2012) can be referred to. Moreover, it can refer also about the material and each member which are used for a dye-sensitized solar cell. Examples of the dye-sensitized solar cell include Japanese Patent Application Laid-Open No. 2001-291534, US Pat. No. 4,927,721, US Pat. No. 4,684,537, US Pat. No. 5,0843,65. No., US Pat. No. 5,350,644, US Pat. No. 5,463,057, US Pat. No. 5,525,440, JP-A-7-249790, JP Reference can be made to 2004-220974 and JP-A-2008-135197.

  Hereinafter, the preferable aspect of the main member and compound of the photoelectric conversion element of this invention and a solar cell is demonstrated.

<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.

  As shown in FIG. 1A and FIGS. 2 to 4, the first electrode 1 includes at least one of a porous layer 12, a blocking layer 14, and an electron transport layer 15 in addition to the conductive support 11 and the photosensitive layer 13. It is preferable to have a layer.

  The first electrode 1 preferably has at least the blocking layer 14 in terms of prevention of short circuit, and more preferably has the porous layer 12 and the blocking layer 14 in terms of light absorption efficiency and prevention of short circuit.

  Moreover, it is preferable that the 1st electrode 1 has the electron carrying layer 15 formed with the organic material at the point of the improvement of productivity of a photoelectric conversion element, thickness reduction, or flexibility.

− 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 conductive material (for example, 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. The structure having is preferable.

In particular, as shown in FIGS. 1A and 2 to 4, a conductive support 11 in which a transparent metal electrode 11 b is formed by coating a conductive metal oxide on the surface of a glass or plastic support 11 a. Is more preferable. Examples of the support 11a made of plastic include a transparent polymer film described in paragraph No. 0153 of JP-A No. 2001-291534. As a material for forming the support 11a, ceramic (for example, see JP-A-2005-135902) or conductive resin (for example, see JP-A-2001-160425) is used in addition to glass and plastic. Can do. As the metal oxide, tin oxide (Tin Oxide: TO) is preferable, indium-tin oxide (tin-doped indium oxide) (Indium Tin Oxide: ITO), fluorine-doped tin oxide (Fluorine doped Tin Oxide: FTO) Particularly preferred are fluorine-doped tin oxides such as The coating amount of the metal oxide at this time 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, light is preferably 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, and particularly preferably 80% or more.

  The thicknesses of the support 11a and the conductive support 11 are not particularly limited, and are set to appropriate thicknesses. 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 providing the transparent electrode 11b, the film thickness of the transparent electrode 11b is not specifically limited, For example, it is preferable that it is 0.01-30 micrometers, It is more preferable that it is 0.03-25 micrometers, 0.05-20 micrometers It is particularly preferred that

  The conductive support 11 or the support 11a may have a light management function on the surface. For example, even if the surface of the conductive support 11 or the support 11a has an antireflection film in which high refractive films and low refractive index oxide films are alternately stacked as described in JP-A-2003-123859. The light guide function described in JP-A-2002-260746 may be provided.

− 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. Between them, the blocking layer 14 is provided.

  In a photoelectric conversion element and a solar cell, for example, when the photosensitive layer 13 or the hole transport layer 3 and the transparent electrode 11b are electrically connected, 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 the light absorber.

  This blocking layer 14 may also be provided when the photoelectric conversion element has an electron transport layer. For example, in the case of the photoelectric conversion element 10 </ b> D, the blocking layer 14 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 capable of fulfilling the above functions, but is a substance that transmits visible light and is an insulating substance for the conductive support 11 (transparent electrode 11b) and the like. It is preferable that Specifically, the “insulating substance with respect to the conductive support 11 (transparent electrode 11b)” specifically refers to a material whose conduction band energy level forms the conductive support 11 (metal oxide forming the transparent electrode 11b). A compound (n-type semiconductor compound) that 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 constituting the porous layer 12 and the ground state of the light absorber.

  Examples of the material for forming the blocking layer 14 include silicon oxide, magnesium oxide, aluminum oxide, calcium carbonate, cesium carbonate, polyvinyl alcohol, and polyurethane. Moreover, the material generally used for the 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 film 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 photoelectric conversion element 10 has the blocking layer 14, the porous layer 12 is preferably formed on the blocking layer 14.

  The porous layer 12 is a layer that functions as a scaffold for carrying the photosensitive layer 13 on the 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 entire surface area of the porous layer 12.

  The porous layer 12 is preferably a fine particle layer having 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 in which two or more kinds of fine particles are deposited. When the porous layer 12 is a fine particle layer having pores, the amount of light absorbent supported (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 constituting the porous layer 12. In the present invention, in a 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, more than 100 times the projected area. It is more preferable. Although there is no restriction | limiting in particular in this upper limit, Usually, it is about 5000 times. The particle diameter of the fine particles forming the porous layer 12 is preferably 0.001 to 1 μm as the primary particle 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 for forming the porous layer 12 is not particularly limited with respect to conductivity, and may be an insulator (insulating material), a conductive material, or a semiconductor (semiconductive material). .

  Examples of the material for forming the porous layer 12 include metal chalcogenides (eg, oxides, sulfides, selenides, etc.), compounds having a perovskite crystal structure (excluding perovskite compounds used as light absorbers), silicon. These oxides (for example, silicon dioxide, zeolite) or carbon nanotubes (including carbon nanowires and carbon nanorods) can be used.

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

  Although it does not specifically limit as a compound which has a perovskite type crystal structure, A transition metal oxide etc. are mentioned. 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, bismuth titanate. Of these, strontium titanate, calcium titanate and the like are preferable.

  The carbon nanotube has a shape obtained by rounding a carbon film (graphene sheet) into a cylindrical shape. The carbon nanotube is a single-walled carbon nanotube (SWCNT) in which one graphene sheet is wound in a cylindrical shape, or a double-walled carbon nanotube (double-walled in which two graphene sheets are wound concentrically). carbon nanotube (DWCNT), and a multi-walled carbon nanotube (MWCNT) in which a plurality of graphene sheets are concentrically wound. As the porous layer 12, any carbon nanotube is not particularly limited and can be used.

  Among these materials, the material forming the porous layer 12 is preferably titanium, tin, zinc, zirconium, aluminum or silicon oxide, or carbon nanotube, and more preferably titanium oxide or aluminum oxide.

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

  Although the film thickness of the porous layer 12 is not specifically limited, Usually, it is the range of 0.05-100 micrometers, Preferably it is the range of 0.1-100 micrometers. When using as a solar cell, 0.1-50 micrometers is preferable and 0.2-30 micrometers is more preferable.

− Electron transport layer 15 −
In the present invention, like the photoelectric conversion element 10D, the electron transport layer 15 is preferably provided on the surface of the transparent electrode 11b.

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 that can exhibit this function. The electron transport material is not particularly limited, but 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-Butylic Acid Methyl Ester (PC ₆₁ BM), perylene compounds such as perylene tetracarboxylic diimide (PTCDI), and other tetra Examples thereof include a low molecular compound such as cyanoquinodimethane (TCNQ) or a high molecular compound.

  Although the film thickness of the electron carrying layer 15 is not specifically limited, 0.001-10 micrometers is preferable and 0.01-1 micrometer is more preferable.

− Photosensitive layer (light absorbing layer) 13 −
The photosensitive layer 13 is preferably a surface of each of the porous layer 12 (photoelectric conversion elements 10A and 10B), the blocking layer 14 (photoelectric conversion element 10C), and the electron transport layer 15 (photoelectric conversion element 10D) (photosensitive layer). 13 is included in the concave surface when the surface on which the surface 13 is provided is uneven.

  In the present invention, the photosensitive layer 13 may contain at least one perovskite compound described later as a light absorber, and may contain two or more perovskite compounds. The photosensitive layer 13 may contain a light absorber other than the perovskite compound as a light absorber in combination with the perovskite compound. Examples of the light absorber other than the perovskite compound include metal complex dyes and organic dyes. At this time, the ratio of the perovskite compound to other light absorbers is not particularly limited.

  The photosensitive layer 13 may be a single layer or a laminate of two or more layers. When the photosensitive layer 13 has a laminated structure of two or more layers, a laminated structure in which layers made of different light absorbers are laminated may be used, and a hole transport material is included between the photosensitive layer and the photosensitive layer. A laminated structure having an intermediate layer may also be used.

  The mode having the photosensitive layer 13 on the conductive support 11 is as described above. The photosensitive layer 13 is preferably provided on the surface of each of the layers 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 of the above layers, 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 having the photosensitive layer 13 on the conductive support 11 and is not particularly limited. For example, 0.001 to 100 μm is preferable, 0.01 to 10 μm is more preferable, and 0.01 to 5 μm is particularly preferable.

  When the porous layer 12 is included, the total film thickness with 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. Further, the total film thickness is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The total film thickness can be in a range where the above values are appropriately combined. Here, as shown in FIGS. 1A and 1B, when the photosensitive layer 13 is a thin film, the thickness of the photosensitive layer 13 is the same as that of the porous layer 12 along the direction perpendicular to the surface of the porous layer 12. The distance between this interface and the interface between the hole transport layer 3 described later.

  In the photoelectric conversion element 10, the total film thickness of the porous layer 12, the photosensitive layer 13, and the hole transport layer 3 is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, and 0 .1 μm or more is more preferable, and 0.5 μm or more is particularly preferable. The total film thickness is preferably 200 μm or less, preferably 50 μm or less, preferably 30 μm or less, and preferably 5 μm or less. The total film thickness can be in a range where 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 the photosensitive layer may function as a hole transport material.

The amount of the perovskite compound used may be an amount that covers at least a part of the surface of the first electrode 1, and is preferably an amount that covers the entire surface.
[Light absorber of photosensitive layer]
The photosensitive layer 13 includes, as light absorbers, “periodic table group 1 element or cationic organic group A”, “metal atom M other than periodic table group 1 element”, and “anionic atom or atomic group X”. And a perovskite compound having a perovskite crystal structure (perovskite light absorber).

  In the perovskite compound, a periodic table group I element or a cationic organic group A, a metal atom M, and an anionic atom or atomic group X are each a cation (for convenience, sometimes referred to as cation A), metal, It exists as constituent ions of a cation (for convenience, sometimes referred to as cation M) and an anion (for convenience, sometimes referred to as anion X).

  In the present invention, the cationic organic group means an organic group having a property of becoming a cation in the perovskite type crystal structure, and the anionic atom or atomic group is an atom or atomic group having a property of becoming an anion in the perovskite type crystal structure. Say.

  In the perovskite compound used in the present invention, the cation A is an organic cation composed of a cation of the group A element of the periodic table or a cationic organic group A. The cation A is preferably an organic cation.

The cation of the Group 1 element of the periodic table is not particularly limited, and for example, the cation (Li ⁺ , Na ⁺ , K ⁺ of each element of lithium (Li), sodium (Na), potassium (K), or cesium (Cs). Cs ⁺ ), and a cesium cation (Cs ⁺ ) is particularly preferable.

The organic cation is not particularly limited as long as it is a cation of an organic group having the above properties, but is more preferably an organic cation of a cationic organic group represented by the following formula (1).
Formula (1): R ^1a -NH ₃ ⁺
In the formula, R ^1a represents a substituent. R ^1a is not particularly limited as long as it is an organic group, but an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, or a group represented by the following formula (2) is preferable. . Among these, an alkyl group and a group represented by the following formula (2) are more preferable.

In formula, ^Xa represents NR ^<1c> , an oxygen atom, or a sulfur atom. R ^1b and R ^1c each independently represent a hydrogen atom or a substituent. *** represents a bond with the nitrogen atom of formula (1).

In the present invention, the organic cation of the cationic organic group A is an organic ammonium cation (R ^1a -NH ₃ ⁺ consisting of an ammonium cationic organic group A formed by bonding R ^1a and NH ₃ in the above formula (1). ) Is preferred. When the organic ammonium cation can take a resonance structure, the organic cation includes a cation having a resonance structure in addition to the organic ammonium cation. For example, in the group that can be represented by the above formula (2), when X ^a is NH (R ^1c is a hydrogen atom), the organic cation is bonded to the group that can be represented by the above formula (2) and NH _3. In addition to the organic ammonium cation of the ammonium cationic organic group, an organic amidinium cation which is one of the resonance structures of the organic ammonium cation is also included. Examples of the organic amidinium cation comprising an amidinium cationic organic group include a cation represented by the following formula (A ^am ). In this specification, a cation represented by the following formula (A ^am ) may be expressed as “R ^1b C (═NH) —NH ₃ ” for convenience.

The alkyl group as R ^1a in formula (1) is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and still more preferably an alkyl group having 1 to 3 carbon atoms. For example, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl, decyl and the like can be mentioned.

The cycloalkyl group as R ^1a is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include cyclopropyl, cyclopentyl, and cyclohexyl.

The alkenyl group as R ^1a is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 6 carbon atoms. For example, vinyl, allyl, butenyl, hexenyl and the like can be mentioned.

The alkynyl group as R ^1a is preferably an alkynyl group having 2 to 18 carbon atoms, and more preferably an alkynyl group having 2 to 4 carbon atoms. For example, ethynyl, butynyl, hexynyl and the like can be mentioned.

The aryl group as R ^1a is preferably an aryl group having 6 to 14 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and examples thereof include phenyl.

The heteroaryl group as R ^1a includes a group consisting only of an aromatic heterocycle and a group consisting of a condensed heterocycle obtained by condensing an aromatic heterocycle with another ring, for example, an aromatic ring, an aliphatic ring or a heterocycle. Include.

  As a ring-constituting hetero atom constituting the aromatic hetero ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. Further, 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 condensed heterocycle including a 5-membered aromatic heterocycle and a 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. , Benzimidazole ring, benzoxazole ring, benzothiazole ring, indoline ring, and indazole ring. Examples of the condensed heterocycle including a 6-membered aromatic heterocycle and a 6-membered aromatic heterocycle include, for example, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, and quinazoline ring. Is mentioned.

In the group that can be represented by the formula (2), X ^a represents NR ^1c , an oxygen atom or a sulfur atom, and NR ^1c is preferable. Here, R ^1c represents a hydrogen atom or a substituent, and is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group or a heteroaryl group, and more preferably a hydrogen atom.

R ^1b represents a hydrogen atom or a substituent, and preferably a hydrogen atom. ^Examples of the substituent that R ^1b can take include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, and an amino group.

The alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group which R ^1b and R ^1c can each have the same meanings as those of R ^1a above, and the preferred ones are also the same.

  Examples of the group that can be represented by the formula (2) 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. The acyl group is preferably an acyl group having 1 to 7 carbon atoms, and examples thereof include formyl, acetyl, propionyl, hexanoyl and the like. The thioacyl group is preferably a thioacyl group having 1 to 7 carbon atoms in total, and examples thereof include thioformyl, thioacetyl, thiopropionyl and the like.

The (thio) carbamoyl group includes a carbamoyl group and a thiocarbamoyl group (H ₂ NC (═S) —).

The imidoyl group is a group represented by R ^1b —C (═NR ^1c ) —, wherein R ^1b and R ^1c are each preferably a hydrogen atom or an alkyl group, and the alkyl group has the same meaning as the alkyl group for R ^1a above. Is more preferable. For example, formimidoyl, acetimidoyl, propionimidoyl (CH ₃ CH ₂ C (═NH) —) and the like can be mentioned. Of these, formimidoyl is preferable.

The amidino group as a group that can be represented by the formula (2) has a structure in which R ^{1b of the} imidoyl group is an amino group and R ^1c is a hydrogen atom.

The alkyl group, the cycloalkyl group, the alkenyl group, the alkynyl group, the aryl group, the heteroaryl group, and the group that can be represented by the above formula (2), which R ^1a can take, may have a substituent. Good. The R ^1a may substituent W ^P that have, but are not limited to, for example, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkylthio group, an amino Group, alkylamino group, arylamino group, acyl group, alkylcarbonyloxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, acylamino group, sulfonamido group, carbamoyl group, sulfamoyl group, halogen atom, cyano group, A hydroxy group, a mercapto group or a carboxy group can be mentioned. Each substituent that R ^1a may have may be further substituted with a substituent.

  In the perovskite compound used in the present invention, the metal cation M is not particularly limited as long as it is a cation of a metal atom M other than a group 1 element of the periodic table and a cation of a metal atom capable of adopting a perovskite crystal structure. Examples of such metal atoms 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), etc. Of the metal atoms. Among these, the metal atom M is particularly preferably a Pb atom or an Sn atom. M may be one type of metal atom or two or more types of metal atoms. In the case of two or more kinds of metal atoms, two kinds of Pb atoms and Sn atoms are preferable. The proportion of metal atoms at this time is not particularly limited.

In the perovskite compound used in the present invention, the anion X represents an anionic atom or an anion of the atomic group X. This anion is preferably an anion of a halogen atom or an anion of each atomic group of NCS ⁻ , NCO ⁻ , CH ₃ COO ⁻ or HCOO ⁻ . Of these, an anion of a halogen atom is more preferable. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, for example.

  The anion X may be an anion of one type of anionic atom or atomic group, or may be an anion of two or more types of anionic atom or atomic group. In the case of one kind of anionic atom or anion of an atomic group, an anion of iodine atom is preferable. On the other hand, in the case of two or more types of anionic atoms or anions of atomic groups, two types of anions of halogen atoms, particularly anions of chlorine atoms and iodine atoms are preferred. The ratio of two or more types of anions is not particularly limited.

The perovskite compound used in the present invention is preferably a perovskite compound having a perovskite crystal structure having each of the above constituent ions and represented by the following formula (I).
Formula (I): A _a M _m X _x
In the formula, A represents a group 1 element of the periodic table or a cationic organic group. M represents a metal atom other than Group 1 elements of the periodic table. X represents an anionic atom or atomic group.

  a represents 1 or 2, m represents 1, and a, m, and x satisfy a + 2m = x.

  In the formula (I), the periodic table group 1 element or the cationic organic group A forms the cation A having a perovskite crystal structure. Accordingly, the Group 1 element of the periodic table and the cationic organic group A are not particularly limited as long as they are elements or groups that can form the perovskite crystal structure by becoming the cation A. The Periodic Table Group 1 element or the cationic organic group A has the same meaning as the Periodic Table Group 1 element or the cationic organic group described above for the cation A, and the preferred ones are also the same.

  The metal atom M is a metal atom that forms the metal cation M having a perovskite crystal structure. Therefore, the metal atom M is not particularly limited as long as it is an atom other than the Group 1 element of the periodic table and can form the perovskite crystal structure by becoming the metal cation M. The metal atom M is synonymous with the metal atom described in the metal cation M, and the preferred ones are also the same.

  The anionic atom or atomic group X forms the anion X having a perovskite crystal structure. Therefore, the anionic atom or atomic group X is not particularly limited as long as it is an atom or atomic group that can form the perovskite crystal structure by becoming the anion X. The anionic atom or atomic group X is synonymous with the anionic atom or atomic group described in the above anion X, and preferred ones are also the same.

When a is 1, the perovskite compound represented by the formula (I) is a perovskite compound represented by the following formula (I-1), and when a is 2, the following formula (I-2) It is a perovskite compound represented.
Formula (I-1): AMX ₃
Formula (I-2): A ₂ MX ₄
In formula (I-1) and formula (I-2), A represents a periodic table group 1 element or a cationic organic group, and is synonymous with A of the said formula (I), and its preferable thing is also the same.

  M represents a metal atom other than the Group 1 element of the periodic table, and is synonymous with M in the above formula (I), and preferred ones are also the same.

  X represents an anionic atom or an atomic group, and is synonymous with X in the formula (I), and preferred ones are also the same.

  The perovskite compound used in the present invention may be either a compound represented by formula (I-1) or a compound represented by formula (I-2), or a mixture thereof. Therefore, in the present invention, at least one perovskite compound only needs to be present as a light absorber, and it is not necessary to clearly distinguish which compound is strictly based on the composition formula, molecular formula, crystal structure, and the like. .

  Specific examples of the perovskite compound that can be used in the present invention are illustrated below, but the present invention is not limited thereto. In the following, the compound represented by the formula (I-1) and the compound represented by the formula (I-2) are described separately. However, even if it is a compound illustrated as a compound represented by a formula (I-1), depending on synthesis conditions etc., it may become a compound represented by a formula (I-2). In some cases, the mixture is a mixture of the compound represented by -1) and the compound represented by formula (I-2). Similarly, even if it is a compound illustrated as a compound represented by a formula (I-2), it may become a compound represented by a formula (I-1), and is represented by a formula (I-1). In some cases, the compound is a mixture of the compound represented by formula (I-2).

Specific examples of the compound represented by formula (I-1) include, for example, CH ₃ NH ₃ PbCl ₃ , CH ₃ NH ₃ PbBr ₃ , CH ₃ NH ₃ PbI ₃ , CH ₃ NH ₃ PbBrI ₂ , and CH ₃ NH _3. PbBr _{2 I,} include _{CH 3 NH 3 SnBr 3, CH} 3 NH 3 SnI 3, CH (= NH) NH 3 PbI 3.

Specific examples of the compound represented by the formula (I-2) include, for example, (C ₂ H ₅ NH ₃ ) ₂ PbI ₄ , (CH ₂ = CHNH ₃ ) ₂ PbI ₄ , (CH≡CNH ₃ ) ₂ PbI _{4 , (n-C 3 H 7} NH 3) 2 PbI 4, (n-C 4 H 9 NH 3) 2 PbI 4, (C 10 H 21 NH 3) 2 PbI 4, (C 6 H 5 NH 3) 2 PbI ₄ , (C ₆ H ₅ CH ₂ CH ₂ NH ₃ ) ₂ PbI ₄ , (C ₆ H ₃ F ₂ NH ₃ ) ₂ PbI ₄ , (C ₆ F ₅ NH ₃ ) ₂ PbI ₄ , (C ₄ H ₃ SNH _{3) 2} PbI ₄ and the like. _{Here, C} 4 _{H 3} SNH 3 in _{(C 4 H 3 SNH 3)} 2 PbI 4 is aminothiophene.

The perovskite compound can be 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 the formula (II), A represents a group 1 element of the periodic table or a cationic organic group, and has the same meaning as A in the formula (I), and preferred ones are also the same. In formula (II), X represents an anionic atom or atomic group, and is synonymous with X in formula (I), and preferred ones are also the same.

  In formula (III), M represents a metal atom other than Group 1 elements of the periodic table, and has the same meaning as M in formula (I), and preferred ones are also the same. In formula (III), X represents an anionic atom or atomic group, and is synonymous with X in formula (I), and preferred ones are also the same.

  For a method for synthesizing perovskite compounds, see, for example, Akihiro Kojima, Kenjiro Teshima, Yasuo Shirai, and Tsutomu Miyasaka, “Organic Halide ssto assVsit assVsit assVsit assVsit esV. Am. Chem. Soc. , 2009, 131 (17), 6050-6051, and the like.

  The usage-amount of a light absorber should just be the quantity which covers at least one part of the surface of the 1st electrode 1, and the quantity which covers the whole surface is preferable.

  In the photosensitive layer 13, the content of the perovskite compound is usually 1 to 100% by mass.

<Hole transport layer 3>
The photoelectric conversion element of this invention has the positive hole transport layer 3 between the 1st electrode 1 and the 2nd electrode 2 like photoelectric conversion element 10A-10D. 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 replenishing electrons to the oxidant of the light absorber, and is preferably a solid layer (solid hole transport layer).

  The hole transport layer 3 contains a polymer having a structural unit represented by the following formula (AI) (hereinafter also referred to as “polymer (A)”) as a hole transport material.

Where
Ar ¹ and Ar ² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.

-(-Z-) _n- represents a linking group necessary for forming a ring together with Ar ¹ and Ar ² linked to each other by a single bond. n represents 1 or 2, and when n is 1, the formed ring is a 5-membered ring, and when n is 2, the formed ring is a 6-membered ring. When n is 2, two Zs may be the same or different.

Z represents —O—, —S—, —C (═O) —, —CR ¹ R ² —, —S (═O) —, —SO ₂ —, —Si (R ³ ) (R ⁴ ) —. , -N (R ⁵ )-, -B (R ⁶ )-, -P (R ⁷ )-or -P (= O) (R ⁸ )-, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or a substituent.

  * Represents a bonded portion with another site constituting the polymer (A).

Hereinafter, the general formula (AI) will be described in detail.
The trivalent aromatic hydrocarbon ring group represented by Ar ¹ and Ar ² is preferably a trivalent aromatic hydrocarbon ring group having 6 to 60 carbon atoms, and may further have a substituent. Good.

  This aromatic hydrocarbon ring group may be a single ring or a condensed ring. In one embodiment of the present invention, the aromatic hydrocarbon ring group is preferably a condensed ring in which 5 or less rings are condensed, or a single ring, more preferably a condensed ring in which two rings are condensed, or a single ring. Rings are more preferred.

  Examples of the aromatic hydrocarbon ring group include benzene, naphthalene, anthracene, fluorene, pyrene, and perylene. Of these, benzene or naphthalene is preferable, and benzene is more preferable.

  The aromatic hydrocarbon ring group may further have a substituent as described above, and in this case, the whole including the substituent is an aromatic hydrocarbon ring group. However, in this case, the carbon number of the preferred aromatic hydrocarbon ring group described above does not include the carbon number of the substituent. As the substituent, a halogen atom, a saturated or unsaturated hydrocarbon group having 1 to 12 carbon atoms, an aryl group having 6 to 60 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, Examples thereof include an alkanoyl group having 1 to 12 carbon atoms, an aryloxy group having 6 to 60 carbon atoms, a heterocyclic group having 3 to 60 carbon atoms, an amino group, a nitro group, and a cyano group.

The trivalent aromatic heterocyclic group represented by Ar ¹ and Ar ² is preferably a trivalent aromatic heterocyclic group having 4 to 60 carbon atoms, and may further have a substituent.

  The aromatic heterocyclic group may be a single ring or a condensed ring. Among these, a condensed ring or a single ring in which 5 or less rings are condensed is preferable, a condensed ring or a single ring in which two rings are condensed is more preferable, and a single ring is more preferable.

  Examples of the ring hetero atom constituting the aromatic hetero ring include an oxygen atom, a sulfur atom, a selenium atom, a silicon atom, and a nitrogen atom. Among them, an oxygen atom, a sulfur atom and a selenium atom are preferable, and a sulfur atom is More preferred. Further, 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 condensed heterocycle including a 5-membered aromatic heterocycle and a 5-membered aromatic heterocycle include a pyrrole ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a triazole ring, a selenazole ring, and a furan ring. , Thiophene ring, silole ring, selenophene ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, benzoselenazole ring, indoline ring, and indazole ring. Examples of the condensed heterocycle including a 6-membered aromatic heterocycle and a 6-membered aromatic heterocycle include, for example, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, and quinazoline ring. Is mentioned.

In one embodiment of the present invention, the aromatic heterocyclic group represented by Ar ¹ and Ar ² preferably contains a sulfur atom, for example, a thiophene ring.

  The aromatic heterocyclic group may further have a substituent as described above. In this case, the carbon number of the preferred aromatic heterocyclic group described above does not include the carbon number of the substituent. Examples of the substituent include the same examples as those described above as the substituent that the aromatic hydrocarbon ring group may have.

In one embodiment of the present invention, n in formula (AI) is 2, and the ring formed by — (— Z—) _n — together with Ar ¹ and Ar ² is preferably a 6-membered ring.

Z is, as described above, —O—, —S—, —C (═O) —, —CR ¹ R ² —, —S (═O) —, —SO ₂ —, —Si (R ³ ) ( R ⁴ ) —, —N (R ⁵ ) —, —B (R ⁶ ) —, —P (R ⁷ ) — or —P (═O) (R ⁸ ) — are represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or a substituent.

Examples of the substituent represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ (hereinafter, R ^{1 to} R ⁸ ) include a halogen atom, an alkyl group, and an alkoxy group. Group, alkylthio group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, acyl group, acyloxy group, amide group, imide group, imino group, amino group, substituted amino group, substituted Examples include silyl group, substituted silyloxy group, substituted silylthio group, substituted silylamino group, monovalent heterocyclic group, heterocyclic oxy group, heterocyclic thio group, arylalkenyl group, arylalkynyl group, carboxyl group, and cyano group.

In —CR ¹ R ² —, R ¹ and R ² may be connected to each other to form a ring. Examples of the ring formed in this case include a cyclopentane ring which may have a substituent, a cyclohexane ring which may have a substituent, a cycloheptane ring which may have a substituent, and the like. Is mentioned.

Examples of the halogen atom represented by R ^{1 to} R ⁸ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group represented by R ^{1 to} R ⁸ may be linear, branched or cyclic. Carbon number of an alkyl group is 1-30 normally. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl tomb, n-pentyl group, isopentyl group, 2- Methylbutyl group, 1-methylbutyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, heptyl group, octyl group, isooctyl group, 2-ethylhexyl group, 3, 7-dimethyloctyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group, hexadecyl tomb, octadecyl group, eicosyl group and other chain alkyl groups, cyclopentyl group, cyclohexyl group, adamantyl group and other cycloalkyl groups Can be mentioned. The alkyl group may have a substituent.

The alkoxy group represented by R ^{1 to} R ⁸ may be linear, branched, or cyclic. Carbon number of the alkoxy group is usually 1-20, and specific examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, Hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group, lauryloxy group, and substituted alkoxy groups Specific examples include trifluoromethoxy group, pentafluoroethoxy group, perfluorobutoxy group, perfluorohexyl group, perfluorooctyl group, methoxymethyloxy group, 2-methoxyethyloxy group and the like having 1 to 20 carbon atoms. Fluorinated alkoxy group The alkoxy group may have a substituent.

The alkylthio group represented by R ^{1 to} R ⁸ may be linear, branched, or cyclic. Carbon number of the alkylthio group is usually 1-20, and specific examples of the alkylthio group include methylthio group, ethylthio group, propylthio group, isopropylthio group, butylthio group, isobutylthio group, tert-butylthio group, pentylthio group, Specific examples of the substituted alkylthio group include hexylthio group, cyclohexylthio group, heptylthio group, octylthio group, 2-ethylhexylthio group, nonylthio group, decylthio group, 3,7-dimethyloctylthio group, and laurylthio group. And a fluorinated alkylthio group having 1 to 20 carbon atoms such as a trifluoromethylthio group. The alkylthio group may have a substituent.

The aryl group represented by R ^{1 to} R ⁸ usually has 6 to 60 carbon atoms. Specific examples of the aryl group include a phenyl group and a C1 to C12 alkoxyphenyl group (C1 to C12 alkoxy is an alkoxy having 1 to 12 carbon atoms. The C1 to C12 alkoxy is preferably a C1 to C8 alkoxy. Yes, more preferably C1 to C6 alkoxy, C1 to C8 alkoxy represents alkoxy having 1 to 8 carbon atoms, and C1 to C6 alkoxy represents alkoxy having 1 to 6 carbon atoms. Specific examples of C1 to C12 alkoxy, C1 to C8 alkoxy and C1 to C6 alkoxy include those described and exemplified for the above alkoxy group, and the same applies to the following, and C1 to C12 alkylphenyl groups (C1 to C1). C12 alkyl indicates alkyl having 1 to 12 carbon atoms, and C1 to C12 alkyl is preferred. Or C1 to C8 alkyl, more preferably C1 to C6 alkyl, C1 to C8 alkyl is an alkyl having 1 to 8 carbon atoms, and C1 to C6 alkyl is an alkyl having 1 to 6 carbon atoms. Specific examples of C1 to C12 alkyl, C1 to C8 alkyl, and C1 to C6 alkyl include those described and exemplified above for the alkyl group, and the same applies to the following. Examples thereof include a naphthyl group, a 2-naphthyl group, and a pentafluorophenyl group.

The aryloxy group represented by R ^{1 to} R ⁸ usually has 6 to 60 carbon atoms. Specific examples of the aryloxy group include a phenoxy group, a C1-C12 alkoxyphenoxy group, a C1-C12 alkylphenoxy group, a 1-naphthyloxy group, and a 2-naphthyloxy group. Specific examples of the substituted aryloxy group As such, a pentafluorophenyloxy group may be mentioned.

The arylthio group represented by R ^{1 to} R ⁸ usually has 6 to 60 carbon atoms. Specific examples of the arylthio group include a phenylthio group, a C1-C12 alkoxyphenylthio group, a C1-C12 alkylphenylthio group, a 1-naphthylthio group, and a 2-naphthylthio group. Specific examples of the substituted arylthio group include And pentafluorophenylthio group.

The arylalkyl group represented by R ^{1 to} R ⁸ usually has 7 to 60 carbon atoms. Specific examples of the arylalkyl group include a phenyl-C1-C12 alkyl group, a C1-C12 alkoxyphenyl-C1-C12 alkyl group, a C1-C12 alkylphenyl-C1-C12 alkyl group, and a 1-naphthyl-C1-C12 alkyl group. , 2-naphthyl-C1-C12 alkyl group.

The arylalkoxy group represented by R ^{1 to} R ⁸ usually has 7 to 60 carbon atoms. Specific examples of the arylalkoxy group include a phenyl-C1-C12 alkoxy group, a C1-C12 alkoxyphenyl-C1-C12 alkoxy group, a C1-C12 alkylphenyl-C1-C12 alkoxy group, and a 1-naphthyl-C1-C12 alkoxy group. , 2-naphthyl-C1-C12 alkoxy group.

The arylalkylthio group represented by R ^{1 to} R ⁸ usually has 7 to 60 carbon atoms. Specific examples of the arylalkylthio group include a phenyl-C1-C12 alkylthio group, a C1-C12 alkoxyphenyl-C1-C12 alkylthio group, a C1-C12 alkylphenyl-C1-C12 alkylthio group, and a 1-naphthyl-C1-C12 alkylthio group. 2-naphthyl-C1-C12 alkylthio group.

The acyl group represented by R ^{1 to} R ⁸ usually has 2 to 20 carbon atoms. Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a benzoyl group, a trifluoroacetyl group, and a pentafluorobenzoyl group.

The acyloxy group represented by R ^{1 to} R ⁸ usually has 2 to 20 carbon atoms. Specific examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group, a trifluoroacetyloxy group, and a pentafluorobenzoyloxy group.

The amide group represented by R ^{1 to} R ⁸ usually has 1 to 20 carbon atoms. An amide group refers to a group obtained by removing a hydrogen atom bonded to a nitrogen atom from an acid amide. Specific examples of the amide group include a formamide group, an acetamide group, a propioamide group, a butyroamide group, a benzamide group, a trifluoroacetamide group, a pentafluorobenzamide group, a diformamide group, a diacetamide group, a dipropioamide group, a dibutyroamide group, and a dibenzamide group. , Ditrifluoroacetamide group and dipentafluorobenzamide group.

The imide group represented by R ^{1 to} R ⁸ refers to a group obtained by removing a hydrogen atom bonded to a nitrogen atom from an acid imide. Specific examples of the imide group include succinimide group and phthalimide group.

The substituted amino group represented by R ^{1 to} R ⁸ usually has 1 to 40 carbon atoms. Specific examples of the substituted amino group include methylamino group, dimethylamino group, ethylamino group, diethylamino group, propylamino group, dipropylamino group, isopropylamino group, diisopropylamino group, butylamino group, isobutylamino group, tert -Butylamino group, pentylamino group, hexylamino group, cyclohexylamino group, heptylamino group, octylamino group, 2-ethylhexylamino group, nonylamino group, decylamino group, 3,7-dimethyloctylamino group, laurylamino group, Cyclopentylamino group, dicyclopentylamino group, cyclohexylamino group, dicyclohexylamino group, pyrrolidyl group, piperidyl group, ditrifluoromethylamino group, phenylamino group, diphenylamino group, C1-C12 alcohol Ruoxyphenylamino group, di (C1-C12 alkoxyphenyl) amino group, di (C1-C12 alkylphenyl) amino group, 1-naphthylamino group, 2-naphthylamino group, pentafluorophenylamino group, pyridylamino group, Dazinylamino group, pyrimidylamino group, pyrazylamino group, triazylamino group, phenyl-C1-C12 alkylamino group, C1-C12 alkoxyphenyl-C1-C12 alkylamino group, C1-C12 alkylphenyl-C1-C12 alkylamino group Group, di (C1-C12 alkoxyphenyl-C1-C12 alkyl) amino group, di (C1-C12 alkylphenyl-C1-C12 alkyl) amino group, 1-naphthyl-C1-C12 alkylamino group, 2-naphthyl-C1 ~ C12 alkyl Mino group, and the like.

Examples of the substituted silyl group represented by R ^{1 to} R ⁸ include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, a triisopropylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, a triphenylsilyl group, and a triphenylsilyl group. -P-xylylsilyl group, tribenzylsilyl group, diphenylmethylsilyl group, tert-butyldiphenylsilyl group, dimethylphenylsilyl group can be mentioned.

Examples of the substituted silyloxy group represented by R ^{1 to} R ⁸ include trimethylsilyloxy group, triethylsilyloxy group, tri-n-propylsilyloxy group, triisopropylsilyloxy group, tert-butyldimethylsilyloxy group, Examples thereof include phenylsilyloxy group, tri-p-xylylsilyloxy group, tribenzylsilyloxy group, diphenylmethylsilyloxy group, tert-butyldiphenylsilyloxy group, and dimethylphenylsilyloxy group.

Examples of the substituted silylthio group represented by R ^{1 to} R ⁸ include trimethylsilylthio group, triethylsilylthio group, tri-n-propylsilylthio group, triisopropylsilylthio group, tert-butyldimethylsilylthio group, Examples include phenylsilylthio group, tri-p-xylylsilylthio group, tribenzylsilylthio group, diphenylmethylsilylthio group, tert-butyldiphenylsilylthio group, and dimethylphenylsilylthio group.

Examples of the substituted silylamino group represented by R ^{1 to} R ⁸ include trimethylsilylamino group, triethylsilylamino group, tri-n-propylsilylamino group, triisopropylsilylamino group, tert-butyldimethylsilylamino group, Phenylsilylamino group, tri-p-xylylsilylamino group, tribenzylsilylamino group, diphenylmethylsilylamino group, tert-butyldiphenylsilylamino group, dimethylphenylsilylamino group, di (trimethylsilyl) amino group, di ( Triethylsilyl) amino group, di (tri-n-propylsilyl) amino group, di (triisopropylsilyl) amino group, di (tert-butyldimethylsilyl) amino group, di (triphenylsilyl) amino group, di (tri -P-xylylsilyl Amino group, di (tribenzylsilyl) amino group, di (diphenylmethyl silyl) amino, di (tert- butyldiphenylsilyl) amino group, di (dimethylphenylsilyl) and amino group.

Examples of the monovalent heterocyclic group represented by R ^{1 to} R ⁸ include furan, thiophene, pyrrole, pyrroline, pyrrolidine, oxazole, isoxazole, thiazole, isothiazole, imidazole, imidazoline, imidazolidine, pyrazole, pyrazoline, and pyrazolidine. , Furazane, triazole, thiadiazole, oxadiazole, tetrazole, pyran, pyridine, piperidine, thiopyran, pyridazine, pyrimidine, pyrazine, piperazine, morpholine, triazine, benzofuran, isobenzofuran, benzothiophene, indole, isoindole, indolizine, indoline , Isoindoline, chromene, chroman, isochroman, benzopyran, quinoline, isoquinoline, quinolidine, benzimidazole, benzothiazole , Indazole, naphthyridine, quinoxaline, quinazoline, quinazolidine, cinnoline, phthalazine, purine, pteridine, carbazole, xanthene, phenanthridine, acridine, β-carboline, perimidine, phenanthroline, thianthrene, phenoxathiin, phenoxazine, phenothiazine, phenazine, etc. And a group obtained by removing one hydrogen atom from the heterocyclic compound. As the monovalent heterocyclic group, a monovalent aromatic heterocyclic group is preferable. The monovalent heterocyclic group may have a substituent.

Examples of the heterocyclic oxy group represented by R ^{1 to} R ⁸ include a group represented by the formula (a1) in which an oxygen atom is bonded to the monovalent heterocyclic group. Examples of the heterocyclic thio group include a group represented by the formula (a2) in which a sulfur atom is bonded to the monovalent heterocyclic group.

In the formula, Ar ⁴¹ and Ar ⁴² each independently represent a monovalent heterocyclic group.

  In the present invention, the heterocyclic oxy group usually has 2 to 60 carbon atoms. Specific examples of the heterocyclic oxy group include thienyloxy group, C1-C12 alkylthienyloxy group, pyrrolyloxy group, furyloxy group, pyridyloxy group, C1-C12 alkylpyridyloxy group, imidazolyloxy group, pyrazolyloxy group, triazolyl group. And a ruoxy group, an oxazolyloxy group, a thiazoleoxy group, and a thiadiazoleoxy group.

  In the present invention, the heterocyclic thio group usually has 2 to 60 carbon atoms. Specific examples of the heterocyclic thio group include thienyl mercapto group, C1-C12 alkyl thienyl mercapto group, pyrrolyl mercapto group, furyl mercapto group, pyridyl mercapto group, C-C12 alkyl pyridyl mercapto group, imidazolyl mercapto group, pyrazolyl mercapto group. , Triazolyl mercapto group, oxazolyl mercapto group, thiazole mercapto group and thiadiazole mercapto group.

  In the present invention, the arylalkenyl group usually has 8 to 20 carbon atoms, and specific examples of the arylalkenyl group include a styryl group.

  In the present invention, the arylalkynyl group usually has 8 to 20 carbon atoms, and specific examples of the arylalkynyl group include a phenylacetylenyl group.

In one embodiment of the present invention, at least one Z in Formula (AI) is preferably —CR ¹ R ² —.
In that case, at least one of R ¹ and R ² is a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a monovalent heterocyclic group, a halogen atom, or a group represented by the following formula (AIV). Preferably there is.

Here, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a monovalent heterocyclic group, and a halogen atom are the alkyl group, alkoxy group, alkylthio group, aryl group, and monovalent complex described in R ^{1 to} R ⁸ . It is synonymous with a cyclic group and a halogen atom, and a preferable thing is also the same.

In one embodiment of the present invention, at least one Z in the formula (AI) is —CR ¹ R ² —, and at least one of R ¹ and R ² is a group represented by the following formula (AIV). It is preferable from a viewpoint of moisture resistance and heat-and-moisture resistance. In this case, since the hydrophobicity of the polymer A is increased and the intrusion of moisture is suppressed, it is presumed that the moisture resistance is improved. Further, it is presumed that the interaction between side chains in addition to the main chain is increased, whereby a preferable arrangement is strengthened and the heat and humidity resistance is improved.

In formula (AIV),
L ¹¹ represents a linking group.
Ar ¹⁰ represents an aryl group or a heteroaryl group.
* Represents a bond part to the carbon atom to which R ¹ or R ² is bonded.

Examples of the linking group represented by L ¹¹ in the formula (AIV) include an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 10 carbon atoms), and an alkenylene group (preferably having 2 carbon atoms). -6), an alkynylene group (preferably having 2 to 6 carbon atoms), -COO-, -CON (Ri)-, -OCO-, -N (Ri) CO-, -OCON (Ri)-, -N (Ri ) COO -, - N (Ri ) CON (Ri) -, - CO -, - CS -, - O -, - S -, - SO -, - SO 2 -, - SO 2 O -, - SO 2 N (Ri)-, -N (Ri)-(wherein Ri represents a hydrogen atom, an aryl group or an alkyl group), or a divalent linking group obtained by combining a plurality of these.

In one embodiment of the present invention, L ¹¹ is preferably an alkylene group or an alkylene group-O-alkylene group.

The aryl group represented by Ar ¹⁰ in formula (AIV) has the same meaning as the aryl group described in the aryl group described in R ^{1 to} R ⁸ , and the preferable one is also the same.

Examples of the heteroaryl group represented by Ar ¹⁰ include furan, thiophene, pyrrole, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole, furazane, triazole, thiadiazole, oxadiazole, tetrazole, pyridine, Pyridazine, pyrimidine, pyrazine, triazine, benzofuran, isobenzofuran, benzothiophene, indole, isoindole, indolizine, quinoline, isoquinoline, benzimidazole, benzothiazole, indazole, naphthyridine, quinoxaline, quinazoline, quinazolidine, cinnoline, phthalazine, purine, Pteridine, carbazole, phenanthridine, acridine, β-carboline, perimidine, phenanthroline, phena And a group obtained by removing one hydrogen atom from an aromatic heterocycle such as gin. The heteroaryl group may have a substituent.

  In one embodiment of the present invention, the polymer (A) preferably has a structural unit represented by the following formula (AII) as a structural unit represented by the formula (AI).

Where
Ar ²¹ and Ar ²² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.

R ²¹ and R ²² each independently represents a hydrogen atom or a substituent. Alternatively, R ²¹ and R ²² may be connected to each other to form a ring.

  * Represents a bonded portion with another site constituting the polymer (A).

The trivalent aromatic hydrocarbon ring group and aromatic heterocyclic group represented by Ar ²¹ and Ar ²² are a trivalent aromatic hydrocarbon ring represented by Ar ¹ and Ar ² in the general formula (AI). It is synonymous with a group and an aromatic heterocyclic group, and a preferable thing is also the same.

In one embodiment of the present invention, at least one of Ar ²¹ and Ar ²² is preferably an aromatic heterocyclic group containing a sulfur atom, and more preferably an aromatic heterocyclic ring containing both sulfur atoms. As the aromatic heterocycle containing a sulfur atom, for example, a thiophene ring is preferable.

Definitions and specific examples of the substituents represented by R ²¹ and R ²² are the same as R ^{1 to} R ⁸ described above, and preferred ones are also the same.

Examples of the ring that R ²¹ and R ²² may be formed by connecting to each other include, for example, a cyclopentane ring which may have a substituent, a cyclohexane ring which may have a substituent, and a substituent. And a cycloheptane ring which may be used.

In one embodiment of the present invention, at least one of R ²¹ and R ²² is a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, a halogen atom, or a group represented by the following formula (AV). Preferably there is.

Here, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, and a halogen atom are represented by R ¹ and R ² described in —CR ¹ R ² — as Z in Formula (AI). Are the same as the alkyl group, alkoxy group, alkylthio group, aryl group, heteroaryl group and halogen atom.

Where
L ²¹ represents a linking group, Ar ²⁰ represents an aryl group or a heteroaryl group, and * represents a bond to the carbon atom to which R ²¹ or R ²² is bonded.

Here, the linking group represented by L ²¹ is synonymous with the linking group represented by L ¹¹ in the general formula (AIV) described above, and preferred ones are also the same.

Furthermore, aryl and heteroaryl groups represented by Ar ²⁰ has the same meaning as the aryl group and heteroaryl group represented by Ar ¹⁰ in general formula (AIV), it is preferable also the same.

In one embodiment of the present invention, at least one of R ²¹ and R ²² is more preferably a group represented by the above formula (AV).

  In one embodiment of the present invention, the polymer (A) preferably has a structural unit represented by the following formula (AIII) as a structural unit represented by the formula (AI).

Where
Ar ³¹ and Ar ³² each independently represent a trivalent aromatic heterocyclic group.

R ³¹ , R ³² , R ³³ and R ³⁴ each independently represent a hydrogen atom or a substituent. Alternatively, two of R ³¹ , R ³² , R ³³ and R ³⁴ are connected to form a ring, and the rest each independently represents a hydrogen atom or a substituent.

  * Represents a bonded portion with another site constituting the polymer (A).

The aromatic heterocyclic group represented by Ar ³¹ and Ar ³² is a trivalent aromatic heterocyclic group containing at least one selected from an oxygen atom, a sulfur atom, a silicon atom, a nitrogen atom and a selenium atom. It is preferably a trivalent aromatic heterocyclic group having 4 to 60 carbon atoms. The aromatic heterocyclic group as Ar ³¹ and Ar ³² may further have a substituent.

  The aromatic heterocyclic group may be a single ring or a condensed ring. Among these, a condensed ring or a single ring in which 5 or less rings are condensed is preferable, a condensed ring or a single ring in which two rings are condensed is more preferable, and a single ring is more preferable.

  As the number of ring members of the aromatic heterocycle, a 3- to 8-membered ring is preferable, and a 5-membered ring or a 6-membered ring is more preferable.

  Examples of the condensed heterocycle containing a 5-membered aromatic heterocycle containing an oxygen atom, sulfur atom, silicon atom, nitrogen atom or selenium atom and a 5-membered aromatic heterocycle include thiophene ring, furan ring, pyrrole And a ring, a silole ring, a selenophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, a pyrazole ring, a furazane ring, a triazole ring, a thiadiazole ring, and an oxadiazole ring. In addition, a fused heterocycle including a 6-membered aromatic heterocycle containing an oxygen atom, sulfur atom, silicon atom, nitrogen atom or selenium atom and a 6-membered aromatic heterocycle includes a pyridine ring, a pyridazine ring, and a pyrimidine. And a ring, a pyrazine ring, a triazine ring, and a silabenzene ring.

In one embodiment of the present invention, at least one of the aromatic heterocyclic groups represented by Ar ³¹ and Ar ³² preferably contains a sulfur atom, and more preferably both contain a sulfur atom. As the aromatic heterocycle containing a sulfur atom, for example, a thiophene ring is preferable.

Definitions and specific examples of substituents represented by R ³¹ , R ³² , R ³³ , R ³⁴ (hereinafter, R ^{31 to} R ³⁴ ) are defined and specific examples of substituents represented by R ^{1 to} R ⁸ described above. Same as example.

Examples of the ring that can be formed by linking two of R ³¹ , R ³² , R ^33, and R ³⁴ include, for example, a cyclopentane ring that may have a substituent and a substituent. Examples include a cyclohexane ring and a cycloheptane ring which may have a substituent.

In one embodiment of the present invention, at least one of R ^{31 to} R ³⁴ is represented by a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, a halogen atom, or the following formula (AVI). It is preferably a group.

Here, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, and a halogen atom are alkyl groups as R ¹ and R ² described in —CR ¹ R ² — as Z in Formula (AI). It is synonymous with a group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group and a halogen atom, and preferred ones are also the same.

Where
L ³¹ represents a linking group, Ar ³⁰ represents an aryl group or a heteroaryl group, and * represents a bond to the carbon atom to which R ³¹ , R ³² , R ³³ or R ³⁴ is bonded.

Here, the linking group represented by L ³¹ has the same meaning as the linking group represented by L ¹¹ in the general formula (AIV) described above, and preferred ones are also the same.

Furthermore, aryl and heteroaryl groups represented by Ar ³⁰ has the same meaning as the aryl group and heteroaryl group represented by Ar ¹⁰ in general formula (AIV), it is preferable also the same.

In one embodiment of the present invention, at least one of R ^{31 to} R ³⁴ is more preferably a group represented by the above formula (AVI).

  The polymer (A) having the structural unit represented by the formula (AI) of the present invention can be synthesized using a coupling reaction, for example, a method described in Chemical Reviews, 2002, 102, 1358. . That is, Negishi coupling using a zinc reagent using transition metal catalyst, Ueda-Kosugi-Stille coupling using tin reagent, Suzuki-Miyaura coupling using boron reagent, Kumada-Tamao using magnesium reagent -Corriu coupling, cross coupling such as Ulsan coupling using a silicon reagent, Ullmann reaction using copper, Yamamoto polymerization using nickel, etc. can be used for the synthesis.

As the transition metal catalyst, metals such as palladium, nickel, copper, cobalt, and iron (described in Journal of the American Chemical Society, 2007, Vol. 129, page 9844) can be used. The metal may have a ligand, such as a phosphorus ligand such as PPh ₃ or P (t-Bu) _3, or an N-heterocyclic carbene ligand (Angewandte Chemie International Edition, 2002, 41 and 1290 pages) are preferably used. Metal reactants such as tin reactant and boron reactant as raw materials are Organic Synthesis Collective Volume, 11, 2009, page 393, Vol. 9, 1998, page 553, Tetrahedron, 1997, 53, 1925. Page, Journal of Organic Chemistry, 1993, Vol. 58, page 904, Japanese Patent Application Laid-Open No. 2005-290001, Japanese Translation of PCT International Publication No. 2010-526853, and the like. The reaction may be performed under microwave irradiation as described in Macromolecular Rapid Communications, 2007, 28, 387.

  Although the molecular weight of the polymer (A) having the structural unit represented by the formula (AI) is not particularly limited, the weight average molecular weight is preferably 500 to 500,000, and more preferably 5,000 to 100,000.

Unless otherwise specified, the molecular weight is a value measured using a GPC (Gel Permeation Chromatography) method, and the molecular weight is a weight average molecular weight in terms of polystyrene. The gel packed in the column used in the GPC method is preferably a gel having an aromatic compound as a repeating unit, and examples thereof include a gel made of a styrene-divinylbenzene copolymer. It is preferable to use 2 to 6 columns connected together. Examples of the solvent used include ether solvents such as tetrahydrofuran, amide solvents of N-methylpyrrolidone, halogen solvents such as chloroform, and aromatic solvents such as 1,2-dichlorobenzene. The measurement is preferably performed at a solvent flow rate in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, the apparatus is not loaded and the measurement can be performed more efficiently. The measurement temperature is preferably 10 to 50 ° C, most preferably 20 to 40 ° C. Measurement can also be performed at 50 ° C. to 200 ° C. using a column having a high usable temperature. In addition, the column and carrier to be used can be appropriately selected according to the physical properties of the polymer compound to be measured. In the present invention, the polymer (A) having the structural unit represented by the formula (AI) is represented by the formula ( It may be a homopolymer composed of the structural unit represented by AI) or a copolymer having other copolymerization components. Although it does not specifically limit as another copolymerization component, For example, what is described in Paragraphs 0026-0102 of Unexamined-Japanese-Patent No. 2013-74136 can be used, These contents are this specification by reference. Captured in the book.

  When the polymer (A) is a copolymer, the copolymerization ratio is not particularly limited, but the structural unit represented by the formula (AI) is preferably 10 to 90 mol% of the whole in terms of a molar ratio. It is preferable that it is mol%.

  As represented by the formula (AII) of the present invention, when the structural unit is asymmetric, a polymer containing the structural unit has regioregularity due to a difference in bonding mode. In the present invention, only one typical binding mode is described, but the present invention is not construed as being limited thereto.

  The copolymer may be a random copolymer, an alternating copolymer, a block copolymer, or a periodic copolymer, but is preferably an alternating copolymer or a periodic copolymer. More preferably, it is a coalescence.

  Specific examples of the structural unit represented by the formula (AI) are shown below, but the present invention is not limited to these. In the specific examples below, “*” represents a bond with another site constituting the polymer (A).

  The hole transport material forming the hole transport layer 3 may include a material other than the polymer (A) having the structural unit represented by the formula (AI). This material 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 transport materials described in paragraph numbers 0209 to 0212 of JP-A No. 2001-291534, for example. 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 tetrahedral structure such as C and Si, and triarylamine. And aromatic amine compounds such as triphenylene compounds, nitrogen-containing heterocyclic compounds, and liquid crystalline cyano compounds.

  The hole transport material that may be contained in addition to the polymer (A) having the structural unit represented by the formula (AI) is preferably an organic hole transport material that can be applied by solution and becomes a solid, specifically, 2,2 ′, 7,7′-tetrakis- (N, N-di-p-methoxyphenylamine) -9,9′-spirobifluorene (2,2 ′, 7,7′-tetrakis- (N , N-di-p-methoxyphenylamine) -9,9'-spirobifluorene) (also referred to as spiro-OMeTAD), poly (3-hexylthiophene-2,5-diyl), 4- (diethylamino) benzaldehyde diphenylhydrazone, poly ( 3, 4-ethylene dioxythiophene (poly (3,4-ethylene dioxythiophene; PEDOT)) and the like.

  Although the film thickness of the positive hole transport layer 3 is not specifically limited, 50 micrometers or less are preferable, 1 nm-10 micrometers are more preferable, 5 nm-5 micrometers are further more preferable, and 10 nm-1 micrometer are especially preferable. The film 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 is 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 2nd electrode 2 will not be specifically limited if it has electroconductivity, Usually, it can be set as the same structure as the electroconductive support body 11. FIG. If the strength is sufficiently maintained, the support 11a is not necessarily required.

  The structure of the second electrode 2 is preferably a structure having a high current collecting effect. In order for light to reach the photosensitive layer 13, at least one of the conductive support 11 and the second electrode 2 must be substantially transparent. In the solar cell of this invention, it is preferable that the electroconductive support body 11 is transparent and sunlight is entered from the support body 11a side. In this case, it is more preferable that the second electrode 2 has a property of reflecting light.

  As a material for forming the second electrode 2, for example, platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium (Pd ), Rhodium (Rh), iridium (Ir), osnium (Os), aluminum (Al), and other metals, the above-described conductive metal oxides, carbon materials, and conductive polymers. The carbon material may be a conductive material formed by bonding carbon atoms to each other, and examples thereof include fullerene, carbon nanotube, graphite, and graphene.

  The second electrode 2 is preferably a metal or conductive metal oxide thin film (including a thin film formed by vapor deposition), or a glass substrate or a plastic substrate having this thin film. As the glass substrate or plastic substrate, glass having a thin film of gold or platinum or glass on which platinum is deposited is preferable.

  The film thickness of the 2nd electrode 2 is not specifically limited, 0.01-100 micrometers is preferable, 0.01-10 micrometers is more preferable, 0.01-1 micrometer is especially preferable.

<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 can be used instead of the blocking layer 14 or together with the blocking layer 14.

A hole blocking layer may be provided between the second electrode 2 and the hole transport layer 3.
<< Solar cell >>
The solar cell of this invention is comprised using the photoelectric conversion element of this invention. For example, as shown in FIG. 1A and FIGS. 2 to 4, a photoelectric conversion element 10 configured to cause the external circuit 6 to work can be used as a solar cell. As the external circuit 6 connected to the first electrode 1 (conductive support 11) and the second electrode 2, known ones can be used without particular limitation.

  The present invention is described in, for example, J.I. Am. Chem. Soc. 2009, 131 (17), p. 6050-6051 and Science, 338, p. 643 (2012).

  In the solar cell of the present invention, it is preferable to seal the side surface with a polymer, an adhesive or the like in order to prevent deterioration of the components and transpiration.

<< Photoelectric Conversion Element and Solar Cell Manufacturing Method >>
The photoelectric conversion element and solar cell of the present invention can be produced by a known production method, for example, J. Org. Am. Chem. Soc. 2009, 131 (17), p. 6050-6051, Science, 338, p. 643 (2012) or the like.

  Below, the manufacturing method of the photoelectric conversion element and solar cell of this invention is demonstrated easily.

  In the production method 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 as desired.

  The blocking layer 14 can be formed by, for example, a method of applying a dispersion containing the insulating material or a precursor compound thereof to the surface of the conductive support 11 and baking 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, a method described in Chemical Review, Vol. 110, page 6595 (2010)). It is done. In these methods, after applying the dispersion (paste) to the surface of the conductive support 11 or the surface of the blocking layer 14, baking may be performed at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours, for example, in air. preferable. Thereby, microparticles | fine-particles can be stuck.

  When firing is performed a plurality of times, the firing temperature other than the last firing (the firing temperature other than the last firing) is preferably performed at a temperature lower than the last firing temperature (the last firing temperature). For example, when a titanium oxide paste is used, the firing temperature other than the last can be set within a range of 50 to 300 ° C. Moreover, the last baking temperature can be set so that it may become higher than the baking temperature other than the last in the range of 100-600 degreeC. When a glass support is used as the support 11a, the firing temperature is preferably 60 to 500 ° C.

The amount of the porous material applied when forming the porous layer 12 is appropriately set according to the thickness of the porous layer 12 and the number of times of application, and is not particularly limited. For example, the coating amount of the porous material per 1 m ² of the surface area of the conductive support 11 is preferably 0.5 to 500 g, and 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 described later.

  Next, the photosensitive layer 13 is provided.

The method for providing the photosensitive layer 13 includes a wet method and a dry method, and is not particularly limited. In the present invention, a wet method is preferred, and for example, a method of contacting with a light absorbent solution containing a perovskite type light absorbent is preferred. In this method, first, a light absorbent solution for forming a photosensitive layer is prepared. The light absorber solution contains MX ₂ and AX, which are raw materials for the perovskite compound. Here, A, M and X have the same meanings as A, M and X in the above formula (I). In this light absorber solution, the molar ratio of MX ₂ to AX is appropriately adjusted according to the purpose. When forming a perovskite compound as a light absorber, the molar ratio of AX to MX ₂ is preferably 1: 1 to 10: 1. This light absorber solution can be prepared by mixing MX ₂ and AX in a predetermined molar ratio and then heating. This forming liquid is usually a solution, but may be a suspension. Although the heating conditions are not particularly limited, the heating temperature is preferably 30 to 200 ° C, more preferably 70 to 150 ° C. The heating time is preferably 0.5 to 100 hours, more preferably 1 to 3 hours. As the solvent or dispersion medium, those described later can be used.

  Next, the surface of the layer that forms the photosensitive layer 13 on the surface of the prepared light absorbent solution (in the photoelectric conversion element 10, one of the porous layer 12, the blocking layer 14, and the electron transport layer 15). Contact. Specifically, it is preferable to apply or immerse the light absorbent solution. The contacting temperature is preferably 5 to 100 ° C., and the immersion time is preferably 5 seconds to 24 hours, and more preferably 20 seconds to 1 hour. When drying the apply | coated light absorber solution, drying by heat is preferable, and it is normally dried by heating at 20-300 degreeC, Preferably it is 50-170 degreeC.

  The photosensitive layer can also be formed according to the method for synthesizing the perovskite compound.

Furthermore, the AX solution containing the AX, and MX ₂ solution containing the MX _2, and separately applied (including immersion method), and a method of drying if necessary. In this method, any solution may be applied first, but preferably the MX ₂ solution is applied first. The molar ratio of AX to MX ₂ in this method, coating conditions, and drying conditions are the same as in the above method. In this method, AX or MX ₂ can be vapor-deposited instead of applying the AX solution and the MX ₂ solution.

Still other methods include dry methods such as vacuum deposition using a compound or mixture from which the solvent of the light absorber solution has been removed. For example, the AX and the MX _2, simultaneously or sequentially, and a method of depositing.

  By these methods, the perovskite compound is formed as a photosensitive layer on the surface of the porous layer 12, the blocking layer 14, or the electron transport layer 15.

  The hole transport layer 3 is formed on the photosensitive layer 13 thus provided.

  The hole transport layer 3 can be formed by applying a hole transport material solution containing a hole transport material and drying it. The concentration of the hole transport material is 0.1 to 1.0 M in that the hole transport material solution has excellent coating properties, and when the porous layer 12 is provided, the hole transport material solution easily penetrates into the pores of the porous layer 12. (Mol / L) is preferred.

  After the hole transport layer 3 is formed, the second electrode 2 is formed to manufacture a photoelectric conversion element.

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

  Each of the dispersions and solutions described above may contain additives such as a dispersion aid and a surfactant, if necessary.

  Examples of the solvent or dispersion medium used in the method for producing a photoelectric conversion element include the solvents described in JP-A No. 2001-291534, but are not particularly limited thereto. In the present invention, an organic solvent is preferable, and an alcohol solvent, an amide solvent, a nitrile solvent, a hydrocarbon solvent, a lactone solvent, a halogen solvent, and a mixed solvent of two or more of these are preferable. As the mixed solvent, a mixed solvent of an alcohol solvent and a solvent selected from an amide solvent, a nitrile solvent, or a hydrocarbon solvent is preferable. Specifically, methanol, ethanol, isopropanol, γ-butyrolactone, chlorobenzene, acetonitrile, N, N′-dimethylformamide (N, N′-dimethylformamide; DMF), dimethylacetamide, or a mixed solvent thereof is preferable.

  The application method of the solution or dispersant forming each layer is not particularly limited, and spin coating, extrusion die coating, blade coating, bar coating, screen printing, stencil printing, roll coating, curtain coating, spray coating, dip coating, inkjet A known coating method such as a printing method or a dipping method can be used. Of these, spin coating, screen printing and the like are preferable.

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

  The photoelectric conversion element produced 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.

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

Example 1 (Production of Photoelectric Conversion Element (Sample No. 101) <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), and the conductive support 11 was produced.
<Preparation of solution for blocking layer>
A 15% by mass isopropanol solution of titanium diisopropoxide bis (acetylacetonate) (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 spray pyrolysis using the prepared 0.02M 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 screen printing method and baked in air at 500 ° C. for 3 hours. Thereafter, the obtained sintered body of titanium oxide was immersed in a 40 mM TiCl ₄ aqueous solution, then heated at 60 ° C. for 1 hour, and subsequently heated at 500 ° C. for 30 minutes, so that the porous layer 12 made of TiO ₂ ( A film thickness of 250 nm) was formed.
<Formation of photosensitive layer 13A>
A 40% methanol solution of methylamine (27.86 mL) and an aqueous solution of 57% by mass of hydrogen iodide (hydroiodic acid, 30 mL) were stirred in a flask at 0 ° C. for 2 hours, then concentrated, and CH ₃ NH _{A 3} I crude was obtained. The obtained crude product of CH ₃ NH ₃ I was dissolved in ethanol and recrystallized with diethyl ether. 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.

Next, 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 40 mass. % Light absorber solution A was prepared.

The prepared light absorbent solution A is applied on the porous layer 12 formed on the conductive support 11 by spin coating (2000 rpm for 60 seconds), and then the applied light absorbent solution A is applied on a hot plate. The film was dried at 100 ° C. for 60 minutes to provide a photosensitive layer 13A (thickness 300 nm (including a thickness of 250 nm of the porous layer 12)) made of a perovskite compound of CH ₃ NH ₃ PbI ₃ .

Thus, the first electrode 1A was produced.
<Synthesis of hole transport material>
[Synthesis of polymer (1)]
For the polymer (1) shown below, the following monomer (1) is prepared with reference to the method described in JP2013-100457A, and the method described in Macromolecules, 1992, Vol. 25, pages 1214-1223 is used. Synthesized with reference.

[Synthesis examples of other polymers]
Polymers (2), (3), (5), (14), (15) and (20) shown below were synthesized in the same manner as polymer (1).

  Polymers (4) and (6) shown below were synthesized in the same manner as polymer (1) by preparing monomers with reference to the method described in JP2013-49842A.

  The polymer (7) shown below was synthesized by the same method as the polymer (1) by preparing a monomer with reference to the method described in Dies and Pigments, 2015, 112, 145-153.

  The polymer (8) shown below was prepared by referring to the following monomer (8) prepared by referring to the method described in JP 2013-100457 A and the following monomer (1), Journal of the American Chemical Society, 2008, The synthesis was conducted with reference to the method described in Volume 130, pages 7670-7785.

  Polymers (9) and (12) shown below were synthesized by the same method as for polymer (8) by adjusting monomers with reference to the method described in JP2013-100457A.

  Polymers (10) and (11) shown below were prepared by adjusting monomers with reference to the methods described in JP2013-49842A and JP2013-100457A, and using the same method as polymer (8). Synthesized.

  Polymer (13) shown below was prepared by referring to the methods described in Journal of the American Chemical Society, 1994, 116, 11115-11722, and JP 2013-100457 A. ).

  Polymers (16) and (17) shown below were synthesized in the same manner as polymer (1) by preparing monomers with reference to the method described in Advanced Materials, 2012, Vol. 24, pages 5428-5432. .

  Polymers (18) and (19) shown below were prepared in the same manner as polymer (1) by preparing monomers with reference to the method described in Organic Letters, 2012, Vol. 14, pp. 628-631. .

  The polymer (21) shown below was synthesized in the same manner as the polymer (1) by preparing a monomer with reference to the method described in Journal of Organic Chemistry, 2014, Vol. 79, pages 9206-9221.

[Molecular weight of each polymer]
Table 1 below summarizes the weight-average molecular weight (Mw) in terms of polystyrene analyzed by GPC for each polymer.

[Hole transport material for comparison]
As a hole transport material for comparison, spiro-MeOTAD (manufactured by Wako Pure Chemical Industries, Ltd.) and P3HT (average molecular weight 40,000 to 70,000) (manufactured by Wako Pure Chemical Industries, Ltd.) shown below were used.

<Preparation of hole transport material solution>
As a hole transport material, the polymer (1) (180 mg) synthesized above was dissolved in chlorobenzene (1 mL). To this chlorobenzene solution, 37.5 μL of an acetonitrile solution prepared by dissolving lithium-bis (trifluoromethanesulfonyl) imide (170 mg) in acetonitrile (1 mL) and t-butylpyridine (TBP, 17.5 μL) were added and mixed. Then, a hole transport layer solution was prepared.
<Formation of hole transport layer 3A>
Next, the prepared hole transport layer solution was applied on the surface of the first electrode 1A by a spin coat method and dried to form a solid hole transport layer 3A (film thickness 100 nm).
<Preparation of the second electrode 2>
Gold was vapor-deposited on the hole transport layer 3A by a vapor deposition method to produce a second electrode 2 (film thickness 100 nm).

  Thus, the photoelectric conversion element 10A (sample number 101) was manufactured.

Each film thickness was observed and measured by SEM according to the above method.
(Production of photoelectric conversion elements (sample numbers 102 to 121, c11 to c12))
In the manufacture of the photoelectric conversion element (sample No. 101), a solution for a hole transport layer containing each of the polymers described in the “hole transport material” column of Table 2 below was used instead of “polymer (1)”. Is similar to the manufacture of the photoelectric conversion element (sample number 101), and the photoelectric conversion elements (sample numbers 102 to 121) of the present invention and the photoelectric conversion elements for comparison (sample numbers c11 to c12) are manufactured, respectively. did. In the comparative sample numbers c11 and c12, the above-described comparative hole transport material was used.
<Evaluation of moisture resistance>
The moisture resistance of the photoelectric conversion element was evaluated as follows.

Three specimens of the photoelectric conversion elements of each sample number were produced in the same manner as in the above production method. For each of the three specimens, a battery characteristic test was performed to measure the current. The average value of the three specimens was used as the initial current of the photoelectric conversion element of each sample number. The battery characteristic test was performed by irradiating 1000 W / m ² of simulated sunlight from a xenon lamp through an AM1.5 filter using a solar simulator “WXS-85H” (manufactured by WACOM). In this test, the current-voltage characteristics were measured using an IV tester to determine the initial photoelectric conversion efficiency (η /%).

  Each of the three specimens of each sample number was stored in a constant temperature and humidity chamber with a temperature of 25 ° C. and a relative humidity of 60% for 24 hours, and then a battery characteristic test was performed in the same manner as described above to obtain a photoelectric conversion efficiency (η /%). Was measured. The average value of the three specimens was defined as the photoelectric conversion efficiency (η /%) after storage of the photoelectric conversion element of each sample number.

  The moisture resistance of the photoelectric conversion element was evaluated according to the following evaluation criteria from the rate of decrease in photoelectric conversion efficiency calculated by the following formula.

Decreasing rate (%) = 100− {100 × (photoelectric conversion efficiency after storage) / (initial photoelectric conversion efficiency)}
− Evaluation criteria for moisture resistance −
A: Reduction rate is less than 15% B: Reduction rate is 15% or more and less than 20% C: Reduction rate is 20% or more and less than 25% D: Reduction rate is 25% or more and less than 30% E: Reduction rate is 30% or more and 40% Less than% F: The reduction rate is 40% or more. The results are shown in Table 2 below.
<Evaluation of heat and humidity resistance>
Three specimens of the photoelectric conversion elements of each sample number were produced in the same manner as in the above production method. For each of the three specimens, a battery characteristic test was performed to measure the current. The average value of the three specimens was used as the initial current of the photoelectric conversion element of each sample number. The battery characteristic test was performed by irradiating 1000 W / m ² of simulated sunlight from a xenon lamp through an AM1.5 filter using a solar simulator “WXS-85H” (manufactured by WACOM). Current-voltage characteristics were measured using an IV tester.

  Next, each of the three specimens of each sample number was left in a constant temperature and humidity chamber with a relative humidity of 60% and a temperature of 45 ° C. for 80 hours, and then a battery characteristic test was performed in the same manner as described above to measure current. The average value of the three specimens was taken as the current after standing of the photoelectric conversion element of each sample number.

  The wet heat resistance of the photoelectric conversion element was evaluated according to the following evaluation criteria from the rate of decrease in current calculated by the following formula.

Reduction rate (%) = [(initial current−current after standing) / (initial current)] × 100
− Humidity and heat resistance evaluation criteria −
A: Reduction rate is less than 15% B: Reduction rate is 15% or more and less than 20% C: Reduction rate is 20% or more and less than 30% D: Reduction rate is 30% or more and less than 40% E: Reduction rate is 40% or more and 50% Less than% F: Reduction rate is 50% or more The results are shown in Table 2 below.

  The photoelectric conversion efficiency of the solar cell of the present invention was a photoelectric conversion efficiency sufficient for normal operation as a solar cell. The average efficiency of sample number 101 was 5.0%.

  As shown in Table 2 above, the photoelectric conversion element of the present invention, which contains a polymer having a structural unit represented by the formula (AI) in the hole transport layer, is excellent in moisture resistance and moisture heat resistance. I understood it.

Example 2
In <Preparation of Hole Transport Material Solution> in Example 1, “Polymer (1)” (180 mg) was dissolved in chlorobenzene (1 mL), and 37.5 μL of acetonitrile was added thereto and mixed, whereby lithium-bis A hole transport layer solution not containing (trifluoromethanesulfonyl) imide and t-butylpyridine was prepared, and the following operation was performed in exactly the same manner as in Example 1 to prepare Sample No. 201.

  The production of the photoelectric conversion element (Sample No. 201) except that the solution for the hole transport layer containing the polymer described in the “Hole transport material” column of Table 3 below was used instead of “Polymer (1)”. Similarly, photoelectric conversion elements (sample numbers 202 to 221) of the present invention and photoelectric conversion elements for comparison (sample numbers c21 to c22) were manufactured, respectively.

  The prepared samples were evaluated in the same manner as in <Evaluation of moisture resistance> and <Evaluation of heat and moisture resistance> in Example 1.

  The results are shown in Table 3 below.

  The photoelectric conversion efficiency of the solar cell of the present invention was a photoelectric conversion efficiency sufficient for normal operation as a solar cell. The average efficiency of sample number 201 was 3.7%.

  As shown in Table 3, the photoelectric conversion element of the present invention containing a polymer having a unit structure represented by the formula (AI) in the hole transport layer is lithium-bis (trifluoromethanesulfonyl). ) It was found that even in a system in which a dopant such as imide and t-butylpyridine is not used in combination, the moisture resistance and heat and heat resistance are excellent.

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 to 10D Photoelectric conversion elements 100A to 100D System M using solar cell Electric motor

Claims (10)

A first electrode comprising a conductive support, a photosensitive layer containing a light absorber provided on the conductive support, a second electrode facing the first electrode, a first electrode and a second electrode A photoelectric conversion element having a hole transport layer between and
The photosensitive layer has, as the light absorber, a cation of a group 1 element of the periodic table or a cationic organic group A, a cation of a metal atom M other than the group 1 element of the periodic table, and an anionic atom or an atomic group X. At least a compound having a perovskite crystal structure containing an anion,
The hole transport layer contains at least a polymer having a structural unit represented by the following formula (AI).
Where
Ar ¹ and Ar ² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.
-(-Z-) _n- represents a linking group necessary for forming a ring together with Ar ¹ and Ar ² linked to each other by a single bond. n represents 1 or 2, and when n is 1, the formed ring is a 5-membered ring, and when n is 2, the formed ring is a 6-membered ring. When n is 2, two Zs may be the same or different.
Z represents —O—, —S—, —C (═O) —, —CR ¹ R ² —, —S (═O) —, —SO ₂ —, —Si (R ³ ) (R ⁴ ) —. , -N (R ⁵ )-, -B (R ⁶ )-, -P (R ⁷ )-or -P (= O) (R ⁸ )-, R ¹ , R ² , R ³ , R ^{4 , R 5, R 6, R} 7 and ^{R 8} are each independently, and display the hydrogen atom or a substituent,
At least one Z is —CR ¹ R ² —, and at least one of R ¹ and R ² is a group represented by the following formula (AIV).
* Represents a bonded portion with another site constituting the polymer.
Where
L ¹¹ represents a linking group, Ar ¹⁰ represents an aryl group or a heteroaryl group, and ** represents a bond to the carbon atom to which R ¹ or R ² is bonded. The photoelectric conversion element according to claim 1, wherein the structural unit represented by the formula (AI) is represented by the following formula (AII).
Where
Ar ²¹ and Ar ²² each independently represent a trivalent aromatic hydrocarbon ring group or an aromatic heterocyclic group.
R ²¹ and R ²² each independently represents a hydrogen atom or a substituent. Alternatively, R ²¹ and R ²² may be connected to each other to form a ring.
* Represents a bonded portion with another site constituting the polymer. The photoelectric conversion element according to claim 1, wherein the structural unit represented by the formula (AI) is represented by the following formula (AIII).
Where
Ar ³¹ and Ar ³² each independently represent a trivalent aromatic heterocyclic group.
R ³¹ , R ³² , R ³³ and R ³⁴ each independently represent a hydrogen atom or a substituent. Alternatively, two of R ³¹ , R ³² , R ³³ and R ³⁴ are connected to form a ring, and the rest each independently represents a hydrogen atom or a substituent.
* Represents a bonded portion with another site constituting the polymer. The photoelectric conversion element according to claim 2, wherein in formula (AII), at least one of R ²¹ and R ²² is a group represented by the following formula (AV).
Where
L ²¹ represents a linking group, Ar ²⁰ represents an aryl group or a heteroaryl group, and ** represents a bond to the carbon atom to which R ²¹ or R ²² is bonded. The photoelectric conversion element according to claim 3, wherein in formula (AIII), at least one of R ³¹ , R ³² , R ³³ and R ³⁴ is a group represented by the following formula (AVI).
Where
L ³¹ represents a linking group, Ar ³⁰ represents an aryl group or a heteroaryl group, and ** represents a bond part to the carbon atom to which R ³¹ , R ³² , R ³³ or R ³⁴ is bonded. The photoelectric conversion element according to claim ¹ , wherein Ar ¹ and Ar ² in the formula (AI) are thiophene rings. The photoelectric conversion element according to claim 1 , wherein n is 2 in the formula (AI). The photoelectric conversion element of Claim 2 or 4 whose Ar < ²¹ > and Ar < ²² > are thiophene rings in Formula (AII). The photoelectric conversion element according to claim 3 , wherein Ar ³¹ and Ar ³² in the formula (AIII) are thiophene rings. The solar cell which comprises the photoelectric conversion element of any one of Claims 1-9 .