JP2018195768A - Photoelectric conversion element, solar battery, method for manufacturing photoelectric conversion element, and composition for photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element and a solar cell exhibiting a high fill factor while containing a perovskite compound in a photosensitive layer, a method for producing a photoelectric conversion element, and a composition for a photoelectric conversion element. A polycyclic compound-containing layer on the side of the conductive support and a second electrode of the polycyclic compound-containing layer between a conductive support forming a first electrode and a second electrode facing the first electrode. A photoelectric conversion element having a hole transporting layer adjacent to the side and a polycyclic compound-containing layer or a photosensitive layer adjacent to the hole transporting layer, wherein the polycyclic compound-containing layer contains a specific polycyclic compound. A device, a solar cell, a method for producing a photoelectric conversion device, and a composition for a photoelectric conversion device containing a specific polycyclic compound. [Selection diagram] Figure 1

Description

  The present invention relates to a photoelectric conversion element, a solar cell, a method for producing a photoelectric conversion element, and a composition for a photoelectric conversion element.

  Photoelectric conversion elements are used in various optical sensors, copying machines, solar cells, and the like. Solar cells are being put into practical use as non-depleting solar energy. Of these, dye-sensitized solar cells using organic dyes or Ru bipyridyl complexes as sensitizers have been actively researched and developed, and the photoelectric conversion efficiency has reached about 11%.

  On the other hand, recently, research results have been reported that solar cells using metal halides as compounds having a perovskite crystal structure can achieve relatively high photoelectric conversion efficiency, and are attracting attention. For example, Patent Document 1 describes a photoelectric conversion element containing a compound having a perovskite crystal structure and a phthalocyanine dye as a light absorber. Patent Document 2 describes a photoelectric conversion element using a compound having a perovskite crystal structure as a light absorber and having a compound such as p-phenylenediamine on the surface of the first electrode. .

JP2015-046585A International Publication No. 2015/163233

  As described above, a photoelectric conversion element using a compound having a perovskite crystal structure (hereinafter also referred to as “perovskite compound”) has achieved a certain result in improving photoelectric conversion efficiency on a trial basis. However, in practice, an increase in the amount of electrical energy that can be extracted from the photoelectric conversion element is required, and further improvement in the performance of photoelectric conversion efficiency is expected.

It is an object of the present invention to provide a photoelectric conversion element having a high fill factor while containing a perovskite compound in a photosensitive layer, and a solar cell using the photoelectric conversion element.
Moreover, this invention makes it a subject to provide the manufacturing method of the said photoelectric conversion element, and the composition for photoelectric conversion elements which can be preferably used for this manufacturing method.

  The present inventors provide a photoelectric conversion element having a photosensitive layer containing a perovskite compound as a light absorber and a layer containing a specific polycyclic compound having at least two groups or salts selected from the following group G (multiple compounds) It was found that a high fill factor is exhibited by constructing a layer structure in which a ring compound-containing layer) is adjacent to the hole transport layer and a polycyclic compound-containing layer or hole transport layer is adjacent to the photosensitive layer. . The present invention has been further studied based on these findings and has been completed.

式中、Ｙ^ＢはＣＲ^１又は窒素原子を示す。Ｘ^ＢはＣＲ^２Ｒ^３、ＳｉＲ^４Ｒ^５、ＮＲ^Ｎ、硫黄原子、セレン原子又は酸素原子を示す。Ｒ^１〜Ｒ^５及びＲ^Ｎは水素原子又は置換基を示す。Ｍ^Ｂは金属原子又は金属酸化物を示す。但し、式（ＢＳ−８）及び式（ＢＳ−９）中のピロール由来の環が置換基を有する場合、置換基は互いに結合して環を形成することはない。
［群Ｇ］−ＯＲ^ａ、−Ｏ⁻Ｙａ^＋、−ＳＲ^ａ、−Ｓ⁻Ｙａ^＋、−ＮＲ^ａＲ^ｂ、−（ＮＲ^ａＲ^ｂＲ^ｃ）^＋Ｙａ⁻、−ＣＯＯＲ^ａ、−ＣＯＯ⁻Ｙａ^＋、−ＳＯ_３Ｒ^ａ、−ＯＳＯ_３Ｒ^ａ、−ＳＯ_３ ⁻Ｙａ^＋、−ＯＳＯ_３ ⁻Ｙａ^＋、−Ｐ（＝Ｏ）（ＯＲ^ａ）_２、−ＯＰ（＝Ｏ）（ＯＲ^ａ）_２、−Ｐ（＝Ｏ）（Ｏ⁻Ｙａ^＋）_２、−ＯＰ（＝Ｏ）（Ｏ⁻Ｙａ^＋）_２、−Ｂ（ＯＲ^ａ）_２及び−Ｂ（ＯＲ^ａ）_３ ⁻Ｙａ^＋
ここで、Ｒ^ａ、Ｒ^ｂ及びＲ^ｃは水素原子又は置換基を示し、Ｙａは対塩を示す。 That is, the above-described problems of the present invention have been solved by the following means.
<1> A polycyclic compound-containing layer on the conductive support side and a second electrode side of the polycyclic compound-containing layer between the conductive support forming the first electrode and the second electrode facing the first electrode A photoelectric conversion element having a hole transport layer adjacent to the photosensitive layer adjacent to the polycyclic compound-containing layer or the hole transport layer,
The polycyclic compound-containing layer is selected from the following group G bonded to the polycyclic structure including a partial structure represented by any of the following formulas (BS-1) to (BS-9) and the polycyclic structure: A photoelectric conversion element comprising a polycyclic compound having at least two groups or salts.

In the formula, Y ^B represents CR ¹ or a nitrogen atom. X ^B represents CR ² R ³ , SiR ⁴ R ⁵ , NR ^N , sulfur atom, selenium atom or oxygen atom. R ¹ to R ⁵ and ^{R N} represents a hydrogen atom or a substituent. M ^B represents a metal atom or a metal oxide. However, when the ring derived from pyrrole in formula (BS-8) and formula (BS-9) has a substituent, the substituents are not bonded to each other to form a ring.
[The group ^{G] -OR a, -O - Ya} +, -SR a, -S - Ya +, -NR a R b, - (NR a R b R c) + Ya -, -COOR a, -COO - _{^{Ya +, -SO 3 R a,}} -OSO 3 R a, -SO 3 - Ya +, -OSO 3 - Ya +, -P (= O) (OR a) 2, -OP (= O) (OR a _{^{) 2, -P (= O)}} (O - Ya +) 2, -OP (= O) (O - Ya +) 2, -B (oR a) 2 and _{^{-B (oR a) 3 - Ya}} +
Here, R ^a , R ^b and R ^c represent a hydrogen atom or a substituent, and Ya represents a counter salt.

<2> The photoelectric conversion according to <1>, wherein the first electrode has a photosensitive layer on a conductive support, and the surface of the photosensitive layer has a polycyclic compound-containing layer and a hole transport layer in this order. element.
<3> The photoelectric conversion element according to <1>, wherein the first electrode has a polycyclic compound-containing layer, a hole transport layer, and a photosensitive layer in this order on the conductive support.

式中、Ｇａ〜Ｇｃは上記の基又は塩を示す。Ｒ^６〜Ｒ^１０は水素原子又は置換基を示す。ｎａは１以上の整数である。環Ｚは炭化水素環又は複素環を示す。＊は多環構造との結合部位を示す。 <4> A group or salt selected from Group G forms a partial structure represented by any of the following formulas (PG-1) to (PG-3) and is bonded to a polycyclic structure < The photoelectric conversion element according to any one of 1> to <3>.

In formula, Ga-Gc shows said group or salt. R ^{6 to} R ¹⁰ represent a hydrogen atom or a substituent. na is an integer of 1 or more. Ring Z represents a hydrocarbon ring or a heterocyclic ring. * Indicates a binding site with a polycyclic structure.

<5> The photoelectric conversion device according to any one of <1> to <4>, wherein at least one of the above-described groups or salts is —NR ^a R ^b or —P (═O) (OR ^a ) ₂ .
<6> The photoelectric conversion element according to any one of <1> to <5>, wherein the polycyclic structure and the ring structure of the hole transport material in the hole transport layer are common.
<7> The photoelectric conversion element according to any one of <1> to <6>, wherein the polycyclic compound-containing layer has a thickness of 1 to 10 nm.
The photoelectric conversion element as described in any one of <1>-<7> in which a <8> positive hole transport layer has a film thickness of 10-50 nm.
<9> A perovskite crystal structure in which the photosensitive layer contains a cation of a group 1 element of the periodic table or a cationic organic group, a cation of a metal atom other than the group 1 element of the periodic table, and an anion of an anionic atom or atomic group The photoelectric conversion element as described in any one of <1>-<8> containing the compound which has this.
<10> A solar cell using the photoelectric conversion element according to any one of <1> to <9>.
<11> A method for producing the photoelectric conversion element according to any one of <1> to <10> above,
A method for producing a photoelectric conversion element, comprising: a step of providing a polycyclic compound-containing layer on a conductive support; and a step of providing a hole transport layer on the surface of the polycyclic compound-containing layer.

式中、Ｙ^ＢはＣＲ^１又は窒素原子を示す。Ｘ^ＢはＣＲ^２Ｒ^３、ＳｉＲ^４Ｒ^５、ＮＲ^Ｎ、硫黄原子、セレン原子又は酸素原子を示す。Ｒ^１〜Ｒ^５及びＲ^Ｎは水素原子又は置換基を示す。Ｍ^Ｂは金属原子又は金属酸化物を示す。但し、式（ＢＳ−８）及び式（ＢＳ−９）中のピロール由来の環が置換基を有する場合、置換基は互いに結合して環を形成することはない。
［群Ｇ３］−ＮＲ^ａＲ^ｂ及び−Ｐ（＝Ｏ）（ＯＲ^ａ）_２
ここで、Ｒ^ａ及びＲ^ｂは水素原子又は置換基を示す。 <12> A polycyclic compound in which at least two groups selected from the following group G3 are bonded to a polycyclic structure containing a partial structure represented by any of the following formulas (BS-1) to (BS-9) And a composition for a photoelectric conversion element containing an aprotic solvent.

In the formula, Y ^B represents CR ¹ or a nitrogen atom. X ^B represents CR ² R ³ , SiR ⁴ R ⁵ , NR ^N , sulfur atom, selenium atom or oxygen atom. R ¹ to R ⁵ and ^{R N} represents a hydrogen atom or a substituent. M ^B represents a metal atom or a metal oxide. However, when the ring derived from pyrrole in formula (BS-8) and formula (BS-9) has a substituent, the substituents are not bonded to each other to form a ring.
[Group G3] —NR ^a R ^b and —P (═O) (OR ^a ) ₂
Here, R ^a and R ^b represent a hydrogen atom or a substituent.

  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 (substitution) 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. Moreover, about the compound which does not specify substituted or unsubstituted, it is the meaning containing the compound which has arbitrary substituents in the range which does not impair the target 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 indicated by a specific symbol, or when a plurality of substituents are specified simultaneously, the respective substituents are the same as or different from each other unless otherwise specified. Also good. 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. Further, a ring such as an aliphatic ring, an aromatic ring, or a hetero ring may be further condensed to form a condensed ring.

  Moreover, the numerical range represented using "to" in this specification means the range which includes the numerical value described before and behind "to" as a lower limit and an upper limit.

  The photoelectric conversion element and solar cell of this invention show a high fill factor. Moreover, the manufacturing method of the photoelectric conversion element of this invention and the composition for photoelectric conversion elements can manufacture suitably the photoelectric conversion element and solar cell of this invention which have the above-mentioned outstanding characteristic.

FIG. 1 is a cross-sectional view schematically showing a preferred embodiment of the photoelectric conversion element of the present invention, including an enlarged view of a circular portion in a layer. FIG. 2 is a 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, including an enlarged view of a circular portion in the layer. FIG. 4 is a cross-sectional view schematically showing still another preferred embodiment of the photoelectric conversion element of the present invention. FIG. 5 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 this invention has the 1st electrode of the form with which the photosensitive layer was provided on the electroconductive support body, and the 2nd electrode facing this 1st electrode. Here, the first electrode and the second electrode face each other means that the first electrode and the second electrode are stacked in contact with each other, and the first electrode and the second electrode are stacked via another layer. Both forms (that is, a form in which the first electrode and the second electrode are provided facing each other across another layer). In the first electrode, the photosensitive layer is disposed on the second electrode side with respect to the conductive support.

In the present invention, having 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. Examples thereof include a porous layer, a blocking layer, an electron transport layer, a hole transport layer, and a polycyclic compound-containing layer described later.
In the present invention, for example, the photosensitive layer may have a thin film shape (see FIG. 1) or a thick film shape on the surface of the porous layer as an embodiment having a photosensitive layer through another layer above the surface of the conductive support. (See FIG. 2), a thin film or thick film on the surface of the blocking layer (see FIG. 3), a thin or thick film on the surface of the electron transport layer (see FIG. 4) And an embodiment provided on the surface of the hole transport layer in a thin film shape or a thick film shape (see FIG. 5). 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 includes a polycyclic compound-containing layer on the conductive support side, and a polycyclic compound-containing layer between the conductive support forming the first electrode and the second electrode facing the first electrode. It has a hole transport layer adjacent to the second electrode side of the compound-containing layer, and a photosensitive layer adjacent to the polycyclic compound-containing layer or hole transport layer. In the photoelectric conversion element of the present invention, the layer structure in which the photosensitive layer, the polycyclic compound-containing layer, and the hole transport layer are laminated adjacent to each other between the conductive support and the second electrode has the following two structures. That is, the first aspect of the layer structure is a layer structure in which a photosensitive layer, a polycyclic compound-containing layer, and a hole transport layer are adjacent in this order. In other words, in the photoelectric conversion element having the layer structure of the first aspect, the first electrode has a photosensitive layer on the conductive support, and the photosensitive layer is between the first electrode and the second electrode. The surface of each of them has a polycyclic compound-containing layer and a hole transport layer in this order.
The second embodiment of the layer structure is a laminated structure in which a polycyclic compound-containing layer, a hole transport layer, and a photosensitive layer are adjacent in this order. In other words, in the photoelectric conversion element having the layer structure of the second aspect, the first electrode has a polycyclic compound-containing layer, a hole transport layer, and a photosensitive layer in this order on the conductive support.
In both of the above embodiments, the photosensitive layer, the polycyclic compound-containing layer, and the hole transport layer are adjacent to each other as described above.

  The photoelectric conversion element of the present invention exhibits a high fill factor by having a polycyclic compound-containing layer adjacent to the predetermined layer. The details of the reason are not yet clear, but are estimated as follows. That is, when a conjugated system in a polycyclic structure, which will be described later of a polycyclic compound, is incorporated into a predetermined layer structure, an excellent charge transfer path can be constructed to enhance charge transfer and charge separation, and reduce internal loss of the device. it is conceivable that. Furthermore, the polycyclic compound layer also functions as an underlayer for the hole transport layer, and makes the orientation of the hole transport material and the interface state between the hole transport layer and the polycyclic compound-containing layer suitable for charge transfer. It can be modified. As described above, the photoelectric conversion element of the present invention exhibits a high fill factor.

  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. 1 and 2).

Hereinafter, the preferable aspect of the photoelectric conversion element of this invention is demonstrated.
1 to 5, the same reference numerals mean the same components (members).
1 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 10E unless otherwise specified. The same applies to the system 100 and the first electrode 1. Further, when the photosensitive layer 13 or the polycyclic compound-containing layer 5 is simply referred to, it means the photosensitive layers 13A to 13C or the polycyclic compound-containing layers 5A to 5C 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. A system 100A shown in FIG. 1 is a system applied to a battery for causing an operation circuit M (for example, an electric motor) to perform work by the external circuit 6 using the photoelectric conversion element 10A.
This photoelectric conversion element 10A has the layer structure of the first aspect. Specifically, on the surface of the first electrode 1A and the photosensitive layer 13A of the first electrode 1A, a polycyclic compound-containing layer as schematically shown in an enlarged cross-sectional area a that is an enlarged cross-sectional area a in FIG. 5A and the hole transport layer 3A are provided in this order, and the second electrode 2 is provided on the hole transport layer 3A.
1 A of 1st electrodes have the electroconductive support body 11 which consists of the support body 11a and the transparent electrode 11b, the porous layer 12, and the photosensitive layer 13A containing the perovskite compound on the surface of the porous layer 12. FIG. 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. In FIG. 2, the polycyclic compound-containing layer of the photoelectric conversion element 10B is the same as the polycyclic compound-containing layer 5A of the photoelectric conversion element 10A shown in FIG. To do. In the photoelectric conversion element 10B, the hole transport layer 3B is thinly provided. The photoelectric conversion element 10B is different from the photoelectric conversion element 10A shown in FIG. 1 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 10C shown in FIG. 3 schematically shows another preferred embodiment of the photoelectric conversion element of the present invention (polycyclic compound-containing layer 5B is shown in an enlarged cross-sectional area a in FIG. 3). 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 10C, the photosensitive layer 13C is formed in a thick film shape on the surface of the blocking layer 14, and the polycyclic compound-containing layer 5B is formed on the surface of the photosensitive layer 13C. 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.

  The photoelectric conversion element 10D shown in FIG. 4 schematically shows another preferred embodiment of the photoelectric conversion element of the present invention. In FIG. 4, the polycyclic compound-containing layer of the photoelectric conversion element 10D is the same as the polycyclic compound-containing layer 5B of the photoelectric conversion element 10C shown in FIG. To do. 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. That is, the first electrode 1 </ b> D includes the conductive support 11 and the electron transport layer 15 and the 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.

A photoelectric conversion element 10E shown in FIG. 5 schematically shows still another preferred embodiment of the photoelectric conversion element of the present invention. A system 100E including the photoelectric conversion element 10E is a system applied to battery use as in the system 100A.
The photoelectric conversion element 10E has the layer structure of the second aspect. Specifically, the first electrode 1 </ b> E, the second electrode 2, and the electron transport layer 4 are provided between the first electrode 1 </ b> E and the second electrode 2. The first electrode 1E includes a conductive support 11, and a polycyclic compound-containing layer 5C, a hole transport layer 16, and a photosensitive layer 13C that are sequentially formed on the conductive support 11. This photoelectric conversion element 10E is preferable in that each layer can be formed of an organic material, like the photoelectric conversion element 10D.

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 transmitted 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 (cation).

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. On the other hand, in the photoelectric conversion element 10E, the electrons emitted from the light absorber reach the second electrode 2 from the photosensitive layer 13C through the electron transport layer 4, and after working in the external circuit 6, the conductive support 11 Then, it returns to the photosensitive layer 13C through the polycyclic compound-containing layer 5C and the hole transport layer 16. The light absorber is reduced by the electrons returning to the photosensitive layer 13C.
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, in the present invention, when the porous layer 12 is provided, the porous layer 12 can be formed of an insulator other than a conventional semiconductor. When the porous layer 12 is formed of a semiconductor, electron conduction occurs in which electrons move inside and between the semiconductor fine particles of the porous layer 12. 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.
Also 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 of the present invention is not limited to the above-described preferred embodiments, and the configuration and the like of each embodiment can be appropriately combined between the respective embodiments without departing from the gist of the present invention.

In this invention, the material and each member which are used for a photoelectric conversion element can be prepared by a conventional method except the material and member prescribed | regulated by this invention. For photoelectric conversion elements or solar cells using perovskite compounds, see, for example, Patent Documents 1 and 2, and J. Org. Am. Chem. Soc. 2009, 131 (17), p. 6050-6051 and Science, 338, p. 643 (2012).
Moreover, it can refer also about the material and each member which are used for a dye-sensitized solar cell. Regarding the dye-sensitized solar cell, for example, Japanese Patent Application Laid-Open No. 2001-291534, US Pat. No. 4,927,721, US Pat. No. 4,684,537, US Pat. No. 5,084,365 Specification, US Pat. No. 5,350,644, US Pat. No. 5,463,057, US Pat. No. 5,525,440, JP-A-7-249790, JP-A-2004 -220974 gazette and JP2008-135197 gazette can be referred to.

  Hereinafter, the preferable aspect of the member and compound with which the photoelectric conversion element of this invention is provided 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 FIGS. 1 to 5, the first electrode 1 includes a porous layer 12, a blocking layer 14, an electron transport layer 15, and at least one layer of a hole transport layer 16 and a polycyclic compound-containing layer 5. It is preferable to have.
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 transport layer 15 or the hole transport layer 16 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, a metal, or a glass or plastic support 11a, and a transparent electrode 11b as a conductive film formed on the surface of the support 11a. The structure having is preferable.

Among these, as shown in FIGS. 1 to 5, a conductive support 11 in which a transparent metal electrode 11b is formed by coating a conductive metal oxide on the surface of a glass or plastic support 11a is more preferable. Examples of the support 11a made of plastic include a transparent polymer film described in paragraph No. 0153 of JP-A No. 2001-291534. As a material for forming the support 11a, ceramic (Japanese Patent Laid-Open No. 2005-135902) and conductive resin (Japanese Patent Laid-Open No. 2001-160425) can be used in addition to glass and plastic. As the metal oxide, tin oxide (TO) is preferable, and fluorine-doped tin oxide such as indium-tin oxide (tin-doped indium oxide: ITO) and fluorine-doped tin oxide (FTO) is particularly preferable. 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 thickness of the support body 11a and the electroconductive support body 11 is not specifically limited, It sets to appropriate thickness. For example, the thickness is preferably 0.01 μm to 10 mm, more preferably 0.1 μm to 5 mm, and particularly preferably 0.3 μm to 4 mm.
When 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 0.02-25 micrometers, 0.025-20 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 the photoelectric conversion element, 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 10D, it may be provided between the conductive support 11 and the electron transport layer 15, and in the case of the photoelectric conversion element 10E, it is provided between the second electrode 2 and the electron transport layer 4. May be.

The material for forming the blocking layer 14 is not particularly limited as long as it is a material that can perform the above function, 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 blocking layer 14 is provided, the porous layer 12 is preferably formed on the blocking layer 14.
The porous layer 12 is a layer that functions as a scaffold 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, 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. Carbon nanotubes are single-walled carbon nanotubes (SWCNT) in which one graphene sheet is wound in a cylindrical shape, double-walled carbon nanotubes (DWCNT) in which two graphene sheets are wound in a concentric shape, and multiple graphene sheets are concentric Are classified into multi-walled carbon nanotubes (MWCNT) wound in a shape. As the porous layer 12, any carbon nanotube is not particularly limited and can be used.

  Among them, 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 transport material include fullerene compounds such as [6,6] -Phenyl-C61-Butylic Acid Methyl Ester (PC ₆₁ BM), perylene compounds such as perylenetetracarboxydiimide (PTCDI), and other tetracyanoquinodimethanes Examples thereof include a low molecular compound such as (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.

-Polycyclic compound-containing layer 5C-
When the photoelectric conversion element of this invention has the layer structure of the said 2nd aspect, as FIG. 5 shows, it has the polycyclic compound containing layer 5C on the surface of the transparent electrode 11b. This polycyclic compound-containing layer 5C is the same as the polycyclic compound-containing layer 5A described later, except that the position where it is formed is different.

− Hole transport layer 16 −
The photoelectric conversion element 10E has the hole transport layer 16 above the transparent electrode 11b and on the surface of the polycyclic compound-containing layer 5C. The hole transport layer 16 is the same as the hole transport layer 3 described later except that the position where it is formed is different.

− Photosensitive layer (light absorbing layer) 13 −
The photosensitive layer 13 is preferably a porous layer 12 (photoelectric conversion elements 10A and 10B), a blocking layer 14 (photoelectric conversion element 10C), an electron transport layer 15 (photoelectric conversion element 10D) or a hole transport layer 16 (photoelectric conversion). It is provided on the surface of each layer of the element 10E) (including the inner surface of the recess when the surface on which the photosensitive layer 13 is provided is uneven).
In the present invention, the perovskite-type light absorber only needs to contain at least one specific perovskite compound described later, and may contain two or more perovskite compounds.
The photosensitive layer 13 may contain a light absorber other than the perovskite compound in combination with the perovskite light absorber. Examples of light absorbers other than the perovskite compound include metal complex dyes and organic dyes. At this time, the ratio between the perovskite light absorber and the other light absorber 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. Usually, the film thickness is, for example, preferably 0.001 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 5 μm.
When the porous layer 12 is 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. 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.
In the present invention, when the photoelectric conversion element has the porous layer 12 and the hole transport layer, the total film thickness of the porous layer 12, the photosensitive layer 13, the polycyclic compound-containing layer 5, and the hole transport layer is particularly limited. However, it is preferably 0.01 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and particularly preferably 0.3 μm or more. The total film thickness is preferably 200 μm or less, more preferably 50 μm or less, still more preferably 30 μm or less, and particularly 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 a thick film shape, the light absorber contained in the photosensitive layer may function as a hole transport material.

[Perovskite light absorber]
The photosensitive layer 13 includes, as a perovskite type light absorber, “periodic table group 1 element or cationic organic group A”, “metal atom M other than periodic table group 1 element”, “anionic atom or atomic group”. Perovskite compounds having "X".
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 a constituent ion 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 a cation of a group 1 element of the periodic table or an organic cation composed of a cationic organic group A. The cation A may be one kind of cation or two or more kinds of cations. In the case of two or more types of cations, it may be a cation of two or more group 1 elements of the periodic table, two or more types of organic cations, and at least one cation of the group 1 element of the periodic table and at least 1 It may contain a seed organic cation. The cation A preferably contains an organic cation, and more preferably an organic cation. The mixing ratio of each cation in the case of two or more cations is not particularly limited.
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 may be represented by an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aliphatic heterocyclic group, or the following formula (2). Preferred groups are preferred. Among these, an alkyl group or a group that can be represented by the following formula (2) is 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 ⁺ comprising 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 that can be ^employed as R ^1a is preferably an alkyl group having 1 to 36 carbon atoms, more preferably an alkyl group having 1 to 18 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms. . For example, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl and the like can be mentioned.
The cycloalkyl group that can be adopted as R ^1a is preferably a cycloalkyl group having 3 to 10 carbon atoms, more preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include cyclopropyl, cyclopentyl, and cyclohexyl.

The alkenyl group that can be adopted as R ^1a is preferably an alkenyl group having 2 to 36 carbon atoms, more 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, etc. are mentioned.
The alkynyl group that can be adopted as R ^1a is preferably an alkynyl group having 2 to 36 carbon atoms, more 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 that can be adopted 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 that can be adopted as R ^1a includes a group consisting of only 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. Is included. As a ring-constituting hetero atom constituting the aromatic hetero ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. Moreover, as a ring member number of an aromatic heterocyclic ring, a 3-8 membered ring is preferable and a 5 membered ring or a 6 membered ring is more preferable. 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.

The aliphatic heterocyclic group that can be adopted as R ^1a is composed of a monocyclic group consisting only of an aliphatic heterocyclic ring and an aliphatic condensed heterocyclic ring obtained by condensing an aliphatic heterocyclic ring with another ring (for example, an aliphatic ring). Group. As a ring-constituting hetero atom constituting the aliphatic hetero ring, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable. Moreover, as a ring member number of an aliphatic heterocyclic ring, a 3-8 membered ring is preferable and a 5 membered ring or a 6 membered ring is more preferable. The aliphatic hetero ring preferably has 0 to 24 carbon atoms, more preferably 1 to 18 carbon atoms, still more preferably 2 to 10, and particularly preferably 3 to 5. Preferable specific examples of the aliphatic heterocycle include pyrrolidine ring, oxolane ring, thiolane ring, piperidine ring, tetrahydrofuran ring, oxane ring (tetrahydropyran ring), thiane ring, piperazine ring, morpholine ring, quinuclidine ring, pyrrolidine ring, azetidine And a ring, an oxetane ring, an aziridine ring, a dioxane ring, a pentamethylene sulfide ring, and γ-butyrolactone.

In the group that can be represented by the formula (2) that can be taken as R ^1a , 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, preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or an aliphatic heterocyclic group, and further a hydrogen atom preferable.
R ^1b represents a hydrogen atom or a substituent, and preferably a hydrogen atom. ^Examples of the substituent that can be adopted as R ^1b include an amino group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, and an aliphatic heterocyclic group.
The alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group or aliphatic heterocyclic group that R ^1b and R ^1c can each have the same meaning as each group of R ^1a above, and are preferable. Is the same.

Examples of the group that can be represented by the formula (2) include (thio) acyl group, (thio) carbamoyl group, imidoyl group, and 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 (CH ₃ C (═O) —), 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 (CH ₃ C (═S) —), thiopropionyl and the like.
The (thio) carbamoyl group includes a carbamoyl group (H ₂ NC (═O) —) 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 (HC (= NH) -) , acetimidoyl _{(CH 3 C (= NH)} -), propionic imidoyl _{(CH 3 CH 2 C (=} NH) -) and the like. Among these, formimidoyl is preferable.
The amidino group as a group that can be represented by the formula (2) has a structure (—C (═NH) NH ₂ ) in which R ^{1b of the} imidoyl group is an amino group and R ^1c is a hydrogen atom.

The alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, aliphatic heterocyclic group and group that can be represented by the above formula (2), which can be adopted as R ^1a , are all substituents. You may have. The substituent that R ^1a may have is not particularly limited, and examples thereof include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic group (heteroaryl group and aliphatic heterocyclic group). ), Alkoxy group, alkylthio group, amino group, alkylamino group, arylamino group, acyl group, alkylcarbonyloxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, acylamino group, sulfonamido group, carbamoyl group, A sulfamoyl group, a halogen atom, a cyano group, a hydroxy 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 other than the 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), Metal atoms such as palladium (Pd), germanium (Ge), tin (Sn), lead (Pb), ytterbium (Yb), europium (Eu), indium (In), titanium (Ti), bismuth (Bi) It is done. M may be one metal cation or two or more metal cations. Among them, the metal cation M is preferably a divalent cation, preferably a divalent lead cation (Pb ²⁺ ), a divalent copper cation (Cu ²⁺ ), a divalent germanium cation (Ge ²⁺ ), and a divalent cation. More preferably, it is at least one selected from the group consisting of tin cations (Sn ²⁺ ), more preferably Pb ²⁺ or Sn ²⁺ , and particularly preferably Pb ²⁺ . In the case of two or more kinds of metal cations, the ratio of the metal cations 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 ⁻ , HO ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ or HCOO ⁻ . Among these, a halogen atom anion 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 kinds of anionic atoms or anions of atomic groups, anions of two 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 formula, A represents a periodic table 1st group element 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. A may include a group 1 element of the periodic table and a cationic organic group.

  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. Accordingly, 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 for the anion X, and the 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. Accordingly, in the present invention, it is sufficient that at least one perovskite compound exists as a light absorber, and it is not necessary to clearly distinguish exactly which compound is 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, CH 3 NH 3} SnBr 3, CH 3 NH 3 SnI 3, CH 3 NH 3 GeCl 3, CH (= NH) NH 3 PbI 3, CsSnI 3, CsGeI 3 and the like.

Specific examples of the compound represented by the formula (I-2) include, for example, (C ₂ H ₅ NH ₃ ) ₂ PbI ₄ , (C ₁₀ H ₂₁ 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 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, (} CH 3 NH 3) 2 CuCl 4, (C 4 H 9 NH 3) 2 GeI 4, include _{(C 3 H 7 NH 3)} 2 FeBr 4. _{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. The compound represented by the formula (II) is usually a compound formed by ionic bonding between a cation A of a periodic table first group element or a cationic organic group and an anionic atom or atomic group X.
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. The compound represented by the formula (III) is usually a compound in which a cation M of a metal atom other than the first group element of the periodic table and an anionic atom or X of an atomic group are ionically bonded.

  Examples of the method for synthesizing the perovskite compound include the methods described in Patent Documents 1 and 2. Also, Akihiro Kojima, Kenjiro Teshima, Yasuo Shirai, and Tsutomu Miyasaka, “Organometric Halide Perovskites as Visible Slightly.” Am. Chem. Soc. 2009, 131 (17), p. The method of 6050-6051 is also mentioned.

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

<Polycyclic compound-containing layer 5>
The photoelectric conversion element of the present invention has a polycyclic compound-containing layer. The position (layer structure) for providing the polycyclic compound-containing layer is as described above.
In the present invention, regardless of the state in which the polycyclic compound is present on the surface of the lower layer, the aggregate of the polycyclic compounds present on the surface of the lower layer is referred to as a polycyclic compound-containing layer. That is, the polycyclic compound-containing layer 5 usually forms a layer (film). However, as long as it contains a polycyclic compound, it does not necessarily have to be a layer (film) covering the entire lower surface. For example, any state of a film shape, a linear shape, and a dispersed shape may be used, or a state in which these are mixed may be used.

The polycyclic compound includes a polycyclic structure including a partial structure represented by any of the following formulas (BS-1) to (BS-9), and at least two groups or salts selected from the following group G: Have. That is, this polycyclic compound includes a partial structure represented by any of the following formulas (BS-1) to (BS-9) and has at least two groups or salts selected from the following group G: It can also be referred to as a compound containing a polycyclic structure.

In the above formula, Y ^B represents CR ¹ or a nitrogen atom. In the formulas, if Y ^B there are a plurality, it is preferable that a plurality of Y ^B may be the same or different, are identical.
X ^B represents CR ² R ³ , SiR ⁴ R ⁵ , NR ^N , sulfur atom, selenium atom or oxygen atom, preferably NR ^N , sulfur atom or oxygen atom, more preferably NR ^N or sulfur atom. It is. In the formulas, if X ^B there are a plurality, it is preferable that a plurality of X ^B may be the same or different, are identical.
In formula (BS-1) ~ formula (BS-3), the combination of ^{X B} and ^{Y B} is not particularly limited, combinations ring containing ^{X B} and ^{Y B} is a thiophene ring or a thiazole ring.
R ^{1 to} R ⁵ and R ^N each represent a hydrogen atom or a substituent, and a hydrogen atom is preferred. The substituents can take as R ¹ to R ⁵ and R ^N, is not particularly limited, is preferably selected from Substituent Group T described later. Preferable substituents include “a more preferable group selected from substituent group T” described later. In the ^formulas, if R 1 to R ⁵ and ^{R N} there are a plurality, the plurality of ^R 1 to R ⁵ and ^{R N} may be the same or different from each other.

M ^B represents a metal atom or a metal oxide. Although it will not specifically limit as a metal atom if it is a metal atom which can form a porphyrin complex, For example, Fe, Mn, Co, Ni, Cu, Zn, or Pb is preferable. The metal oxide is not particularly limited as long as it is a metal oxide capable of forming a porphyrin complex. For example, titanyloxy, vanadyloxy, or molybdyloxy is preferable.

  The partial structure is preferably a partial structure represented by any of the formulas (BS-1) to (BS-5) from the viewpoint of improving the fill factor, and is represented by the formula (BS-1) or the formula (BS-5). ) Is more preferable.

The polycyclic structure of the polycyclic compound includes the above partial structure. In the present invention, including a partial structure includes both of an aspect in which the partial structure itself forms a polycyclic structure and an aspect in which a partial structure and another ring are condensed to form a polycyclic structure. .
The other ring condensed with the partial structure may be an aliphatic ring, an aromatic ring, a monocyclic ring or a condensed ring, and may be a hydrocarbon ring or a heterocyclic ring. When the other ring is a condensed ring, the condensed ring includes a ring having a partial structure represented by the above formulas. The other ring is preferably a monocyclic or condensed aromatic hydrocarbon ring or a monocyclic or condensed aromatic heterocycle. It does not specifically limit as an aromatic hydrocarbon ring, For example, the ring which forms the aryl group in the substituent group T mentioned later is mentioned. Moreover, it does not specifically limit as an aromatic heterocycle, For example, the ring which forms the heteroaryl group in the substituent group T mentioned later is mentioned. Among them, the aromatic hydrocarbon ring or aromatic heterocycle is preferably a benzene ring, naphthalene ring, anthracene ring, thiophene ring, benzothiophene ring, pyrrole ring, furan ring, or a condensed ring formed by combining two or more of these. . Examples of the polycyclic structure formed by condensing a partial structure with another ring include compound examples a-15 to a-23 described later.
In the present invention, an embodiment in which the partial structure itself forms a polycyclic structure is preferable.

  The polycyclic structure is preferably in common with the ring structure of the hole transport material contained in the hole transport layer described later. Here, the common ring structure means that one of the ring structures is included in the other ring structure in addition to the aspect in which the ring structures of the polycyclic structure and the hole transport material are matched (partially matches). Including embodiments. For example, the polycyclic structure represented by the above formula (BS-1) is a ring structure of a hole transport material represented by the following formula (H-12) (the structure D in the formula is represented by the formula (D-1 ) (Ring A is a benzene ring)). The polycyclic structure represented by the above formula (BS-1) is a part of the ring structure of the hole transport material represented by the formula (H-7) described later, They are common in terms of the polycyclic structure represented by the formula (BS-1).

The polycyclic structure may have a substituent. Although it does not specifically limit as a substituent which a polycyclic structure may have, Preferably, it selects from the substituent group T mentioned later. Preferable substituents include “a more preferable group selected from substituent group T” described later. When the polycyclic structure has a plurality of substituents, the plurality of substituents may be the same or different.
However, when the pyrrole-derived ring in the above formulas (BS-8) and (BS-9) has a substituent, the substituent is bonded to the pyrrole-derived ring to form a ring (particularly a benzene ring). There is no.

The polycyclic structure has at least two groups or salts selected from the following group G (hereinafter sometimes referred to as group G). The number of groups G included in the polycyclic structure is preferably 2 to 8, more preferably 2 to 4, and still more preferably 2.
[The group ^{G] -OR a, -O - Ya} +, -SR a, -S - Ya +, -NR a R b, - (NR a R b R c) + Ya -, -COOR a, -COO - _{^{Ya +, -SO 3 R a,}} -OSO 3 R a, -SO 3 - Ya +, -OSO 3 - Ya +, -P (= O) (OR a) 2, -OP (= O) (OR a _{^{) 2, -P (= O)}} (O - Ya +) 2, -OP (= O) (O - Ya +) 2, -B (oR a) 2 and _{^{-B (oR a) 3 - Ya}} +

In each of the above groups or salts, R ^a , R ^b and R ^c represent a hydrogen atom or a substituent, and preferably a hydrogen atom. Although it does not specifically limit as a substituent which can be taken as R ^<a> , R ^<b> and R ^<c >, Preferably, it selects from the substituent group T mentioned later. Preferable substituents include “more preferable groups selected from substituent group T” described later, and more preferable substituents include alkyl groups (particularly preferably 1 or 2 carbon atoms). In each formula, R ^a , R ^b and R ^c may be the same or different from each other. In —P (═O) (OR ^a ) ₂ , —OP (═O) (OR ^a ) _2, and —B (OR ^a ) ₂ , one R ^a can also take ^a counter salt Ya.
Ya represents a counter salt. The counter salt Ya is not particularly limited, and includes various cations or anions. Examples of the cation include lithium ion (Li ⁺ ), cesium ion (Cs ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), silver ion (Ag ⁺ ), copper ion (Cu ⁺ ), and ammonium ion. (NR ^d ₄ ⁺ ), phosphonium ion (PR ^d ₄ ⁺ ) and the like. R ^d represents a hydrogen atom or a substituent. The substituent that can be taken as R ^d has the same meaning as the substituent that can be taken as R ^a . Examples of the anion include halide ions (fluoride ions (F ⁻ ), iodide ions (I ⁻ ), bromide ions (Br ⁻ ), chloride ions (Cl ⁻ ), etc.), O ^{2− and the} like. Among these, halide ions are preferable, and iodide ions (I ⁻ ) are more preferable. R ^a , R ^b , R ^c and Ya may each take a dissociated form or may be a salt form.

At least one of the groups G is preferably a group or salt selected from the following group G1, more preferably a group or salt selected from the following group G2, and even more preferably a group selected from the following group G3. Or a salt.
The two or more groups G are each preferably a group or salt selected from the following group G1, more preferably a group or salt selected from the following group G2, and selected from the following group G3. More preferably, it is a group or a salt.
[Group ^{G1] -OR a, -O - Ya} +, -COOR a, -COO - Ya +, -NR a R b, - (NR a R b R c) + Ya -, -P (= O) ( OR ^a ) ₂ , —OP (═O) (OR ^a ) ₂
[Group ^{G2] -OR a, -COOR a,} -NR a R b, -P (= O) (OR a) 2
[Group G3] —NR ^a R ^b and —P (═O) (OR ^a ) ₂

  In the polycyclic compound, the combination of the polycyclic structure and the group G is not particularly limited. For example, the combination of the preferable thing of a polycyclic structure and the preferable thing of group G is mentioned.

The group G is bonded to the polycyclic structure (ring member atom) directly or through a linking group.
The polycyclic structure of the polycyclic compound contains the above partial structure, and may further contain other rings fused to this partial structure. In the present invention, the mode in which the group G is bonded to the polycyclic structure includes the mode in which the group G is bonded to the ring member atom forming the partial structure, the mode of bonding to the ring member atom forming the other ring, and the partial structure. And an embodiment in which each is bonded to a ring member atom forming the other ring. The group G is usually bonded to a ring member atom from which a hydrogen atom has been removed. In addition, a substituent may be bonded to a ring constituent atom other than these.
The linking group is not particularly limited as long as it connects the polycyclic structure and the group G. For example, a divalent group obtained by further removing a hydrogen atom from a group in the substituent group T described later, or the divalent group. And a group formed by combining a plurality of these groups.
Examples of the linking group to which the group G is bonded include groups having a partial structure represented by any of the following formulas (PG-1) to (PG-3). That is, the group G preferably forms a partial structure represented by any of the following formulas (PG-1) to (PG-3) and is bonded to the polycyclic structure.

In the formula, * represents a binding site with a polycyclic structure. This binding site is directly bonded to the polycyclic structure or bonded to the polycyclic structure via another group according to an embodiment described later.
Ga to Gc represent the group G.
R ^{6 to} R ¹⁰ represent a hydrogen atom or a substituent, R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are preferably a hydrogen atom, and R ⁸ is preferably a substituent. The substituents can take as R ⁶ to R ^10, is not particularly limited, is preferably selected from Substituent Group T described later. Preferable substituents include “a more preferable group selected from substituent group T” described later. In each formula, R ⁶ and R ⁷ , and R ⁸ and R ⁹ may be the same or different from each other.
na is an integer greater than or equal to 1, Preferably it is an integer of 1-18, More preferably, it is an integer of 1-8, More preferably, it is 1 or 2.

Ring Z represents a hydrocarbon ring or a heterocyclic ring. Ring Z is a ring containing “C” in formula (PG-3) as a ring-constituting atom. The hydrocarbon ring may be an aliphatic ring or an aromatic ring, and may be a single ring or a condensed ring. Examples of the hydrocarbon ring include a ring forming an aryl group in the substituent group T described later, or a condensed ring formed by condensing two or more of these rings.
The heterocyclic ring may be an aliphatic ring or an aromatic ring, and may be a monocyclic ring or a condensed ring. For example, the aromatic heterocycle is not particularly limited, but a ring forming a heteroaryl group in the substituent group T, a condensed ring formed by condensing two or more of these rings, or a ring forming a heteroaryl group And a condensed ring formed by condensing one or more of the above and a ring forming an aryl group in the substituent group T. Although it does not specifically limit as an aliphatic heterocyclic ring, Among the heterocyclic rings in the substituent group T, an aliphatic heterocyclic ring, a condensed ring in which two or more of these are condensed, or one or more aliphatic heterocyclic rings and a substituent The condensed ring which the aryl group in group T condensed is mentioned.
As the heterocyclic ring, an aliphatic heterocyclic ring is preferable, and a 5-membered or 6-membered aliphatic heterocyclic ring is more preferable. Specific examples include a thiazolidine ring, an oxazolidine ring, a cyclic ether ring (for example, a tetrahydrothiophene ring), and the like.

Ring Z is a ring-constituting atom, usually at least one —CH ₂ — constituting the ring is —C (═O) —, —C (═S) —, —C (═NR ¹¹ ) — and —C. It may be substituted by any one selected from the group consisting of (= CR ¹² R ¹³ )-. In the present invention, each structural element included in the above group may be referred to as an unsaturated bond forming atom for convenience. Among them, the unsaturated bond forming atom is preferably —C (═O) — or —C (═S) —. When a plurality of ring-forming atoms forming the ring Z are substituted with unsaturated bond forming atoms, the plurality of unsaturated bond forming atoms may be the same or different. For example, two constituting a ring CH ₂ - include aspects substituted with city - each -C (= O) - and -C (= S).
R ¹¹ , R ¹² and R ¹³ each represent a hydrogen atom or a substituent. The substituent that can be adopted as R ¹¹ , R ^12, and R ¹³ is not particularly limited, and examples thereof include groups included in the substituent group T described later. When R ¹² and R ¹³ take a substituent, they may be bonded to each other to form a ring.

Ring Z (hydrocarbon ring and heterocyclic ring) may have a substituent (excluding ═O, ═S, ═NR ¹¹ and ═CR ¹² R ^13, which the unsaturated bond-forming atom has). . The substituent that the ring Z may have is not particularly limited, but is preferably selected from the substituent group T described later. When the ring Z has a plurality of substituents, the plurality of substituents may be the same as or different from each other.

In the partial structure represented by the above formula (PG-3), Gc may be directly bonded to ring Z (ring constituting atom of ring Z) or bonded to ring Z via a linking group. May be. Furthermore, when the ring Z has the unsaturated bond forming atom, it may be bonded to R ¹¹ , R ¹² or R ¹³ . The linking group for linking the ring Z and Gc is not particularly limited, and for example, a divalent group obtained by further removing a hydrogen atom from a group in the substituent group T described later, or a combination of a plurality of these divalent groups. Groups. Examples include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, a heteroarylene group, or a heterocyclic group, and an alkylene group (for example, having 1 to 6 carbon atoms) is preferable.

  The linking group to which the group G is bonded is a group having the above-mentioned partial structure, and includes both an aspect formed by the partial structure itself and an aspect formed by combining the partial structure and another group. Include. The linking group to which the group G is bonded may be directly bonded to the polycyclic structure or may be bonded via another group depending on the embodiment. In particular, the partial structure represented by the formula (PG-3) is preferably bonded to the polycyclic structure via another group. The other group is not particularly limited, and examples thereof include a divalent group obtained by further removing a hydrogen atom from a group in the substituent group T described later, or a group formed by combining a plurality of these divalent groups. . Specific examples include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, a heteroarylene group, and a heterocyclic group, and a heteroarylene group is preferable. One or a plurality of other groups may be set appropriately.

  The atom (position) to which the group G is bonded to the polycyclic structure is not particularly limited, but is preferably a ring-constituting atom that forms each ring located at both ends of the rings that form the polycyclic structure.

  Specific examples of the polycyclic compound that can be used in the present invention are illustrated below, but the present invention is not limited thereby. In the following examples, Et represents ethyl.

In the present specification, when it is only described as a substituent, it refers to the following substituent group T, and when each group, for example, an alkyl group is only described, Preferred ranges and specific examples of the corresponding group of the substituent group T are applied.
Further, in this specification, when an alkyl group is described separately from a cyclic (cyclo) alkyl group, the alkyl group is used in the meaning including a linear alkyl group and a branched alkyl group. On the other hand, when the alkyl group is not described separately from the cyclic alkyl group (when simply described as an alkyl group), and unless otherwise specified, the alkyl group is a linear alkyl group or a branched alkyl group. And cycloalkyl group. The same applies to a group or a linking group containing a group that can take a cyclic structure, and a compound containing a group that can take a cyclic structure. When the group can form a cyclic skeleton, the lower limit of the number of atoms of the group forming the cyclic skeleton is 3 or more, and preferably 5 or more, regardless of the lower limit of the number of atoms specifically described for the group.
In the following description of the substituent group T, for example, in order to clarify a linear or branched group and a cyclic group such as an alkyl group and a cycloalkyl group, they are described separately. Yes.

<Substituent group T>
In the present invention, preferable substituents include the following groups and groups formed by combining a plurality of the following groups.
An alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12, more preferably 1 to 6), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, still more preferably 1 to 6 carbon atoms). ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12, more preferably 1 to 6), a cycloalkyl group (preferably having 3 to 20 carbon atoms, more preferably 3 to 6), cycloalkenyl Group (preferably having 5 to 20 carbon atoms), aryl group (aromatic hydrocarbon ring group, preferably 6 to 26 carbon atoms, more preferably 6 to 10), heterocyclic group (at least one oxygen atom as a ring-constituting atom) , Having a sulfur atom and a nitrogen atom, preferably having 2 to 20 carbon atoms, more preferably a 5-membered ring or a 6-membered ring, and heterocyclic groups include aromatic heterocyclic groups (referred to as heteroaryl groups) and Including an aliphatic heterocyclic group), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12, more preferably 1 to 6), and an alkenyloxy group (preferably having 2 to 20 carbon atoms, more preferably). 2-12), an alkynyloxy group (preferably having 2-20 carbon atoms, more preferably 2-12), a cycloalkyloxy group (preferably having 3-20 carbon atoms, more preferably 3-6), an aryloxy group (Preferably having 6 to 26 carbon atoms), a heterocyclic oxy group (preferably having 2 to 20 carbon atoms),

An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms), a cycloalkoxycarbonyl group (preferably having 4 to 20 carbon atoms), an aryloxycarbonyl group (preferably having 6 to 20 carbon atoms), an amino group (preferably having 0 to 0 carbon atoms). 20, an alkylamino group, an alkenylamino group, an alkynylamino group, a cycloalkylamino group, a cycloalkenylamino group, an arylamino group, a heterocyclic amino group), a sulfamoyl group (preferably having 0 to 20 carbon atoms and an alkyl group) , A cycloalkyl or aryl sulfamoyl group is preferred), an acyl group (preferably having 1 to 20 carbon atoms), an acyloxy group (preferably having 1 to 20 carbon atoms), a carbamoyl group (preferably having 1 to 20 carbon atoms, alkyl, Preferred is a cycloalkyl or aryl carbamoyl group For example, N, N- dimethylcarbamoyl, N- cyclohexylcarbamoyl or N- phenylcarbamoyl),

An acylamino group (preferably having 1 to 20 carbon atoms), a sulfonamide group (preferably an alkyl, cycloalkyl or aryl sulfonamide group having 0 to 20 carbon atoms), an alkylthio group (preferably having 1 to 20 carbon atoms, More preferably, it is 1-12, More preferably, it is 1-6, A cycloalkylthio group (preferably C3-C20, More preferably, 31-6), Arylthio group (Preferably C6-C26, More preferably 6 To 10), a heterocyclic thio group (preferably having 2 to 20 carbon atoms), an alkyl, cycloalkyl or arylsulfonyl group (preferably having 1 to 20 carbon atoms),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted by alkyl, aryl, alkoxy and aryloxy), a silyloxy group (preferably having 1 to 20 carbon atoms, alkyl, aryl, alkoxy and aryloxy are A substituted silyloxy group is preferred), a hydroxy group, a cyano group, a nitro group, or a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom or an iodine atom).

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

  The polycyclic compound-containing layer 5 only needs to contain at least one kind of the polycyclic compound, and may contain a plurality of kinds. Further, the content of the polycyclic compound in the polycyclic compound-containing layer 5 is not particularly limited as long as the effect of the present invention is exhibited, and can be set to 0.1 to 100% by mass, for example, and 10 to 100%. It can also be made into the mass%.

  The film thickness of the polycyclic compound-containing layer 5 is not particularly limited, but is preferably 0.01 to 1000 nm, more preferably 0.1 to 100 nm, and still more preferably 1 to 10 nm.

<Hole transport layer 3>
The photoelectric conversion element of the present invention has the hole transport layer 3 on the polycyclic compound-containing layer 5.
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).

  As the hole transport material for forming the hole transport layer 3, a known material can be used without particular limitation as long as it exhibits the above function. The hole transport material used may be a liquid material or a solid material, but a solid material that can be applied by a solution is preferred. Examples thereof include organic hole transport materials described in paragraph Nos. 0209 to 0212 of JP-A No. 2001-291534. The organic hole transport material is preferably a conductive polymer such as polythiophene, polyaniline, polypyrrole and polysilane, a spiro compound in which two rings have a tetrahedral structure such as C and Si, triarylamino, etc. And aromatic amine compounds having a group, triphenylene compounds, nitrogen-containing heterocyclic compounds, cyclic compounds such as porphyrins, phthalocyanines, naphthalocyanines, liquid crystalline cyano compounds, and the like. In addition, the hole transport material described in International Publication Nos. 2015/107454, 2015/114521, or 2014/111365 is mentioned.

式（Ｈ−１）中、環Ａ〜Ｄは芳香族環又は芳香族へテロ環を示し、Ｌは連結基を表す。
芳香族環としては、特に限定されないが、単環でも縮合環でもよく、上記置換基群Ｔにおけるアリール基、又は、これらの２つ以上が縮合した縮合環が挙げられる。芳香族ヘテロ環としては、特に限定されないが、単環でも縮合環でもよく、上記置換基群Ｔにおけるヘテロアリール基、これらの２つ以上が縮合した縮合環、又は、ヘテロアリール基の１つ以上と上記アリール基とが縮合した縮合環が挙げられる。芳香族環又は芳香族へテロ環としては、具体的には、ベンゼン環、フルオレン環、カルバゾール環、ナフタレン環、ピリジン環、チオフェン環、ピロール環、フラン環、チアゾール環、オキサゾール環、イミダゾール環、ベンゾチオフェン環、ベンゾフラン環等が挙げられる。
環Ａ〜Ｄは、同一でも異なっていてもよい。
連結基Ｌとしては、特に限定されないが、例えば、アルキレン基、アルケニレン基、アルキニレン基、アリーレン基、ヘテロアリーレン基、ヘテロ環基が挙げられる。 Preferable hole transport materials include, for example, those represented by any of the following formulas (H-1) to (H-12).

In formula (H-1), rings AD represent an aromatic ring or an aromatic heterocycle, and L represents a linking group.
The aromatic ring is not particularly limited, and may be a single ring or a condensed ring, and examples thereof include an aryl group in the substituent group T or a condensed ring in which two or more of these are condensed. The aromatic heterocycle is not particularly limited, and may be a single ring or a condensed ring. The heteroaryl group in the above substituent group T, a condensed ring obtained by condensing two or more of these, or one or more heteroaryl groups And a condensed ring in which the aryl group is condensed. Specific examples of the aromatic ring or aromatic heterocycle include benzene ring, fluorene ring, carbazole ring, naphthalene ring, pyridine ring, thiophene ring, pyrrole ring, furan ring, thiazole ring, oxazole ring, imidazole ring, Examples include a benzothiophene ring and a benzofuran ring.
Rings A to D may be the same or different.
The linking group L is not particularly limited, and examples thereof include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, a heteroarylene group, and a heterocyclic group.

式（Ｈ−２）〜式（Ｈ−７）中、Ａは、硫黄原子、酸素原子、セレン原子、ＮＲ、ＳｉＲ_２又はＣＲ_２を示す。中でも、ＮＲ、ＣＲ_２又は硫黄原子が好ましい。各式中、Ａが複数存在する場合、複数のＡは同一でも異なっていてもよい。
ＢはＣＲ又は窒素原子を示す。各式中、Ｂが複数存在する場合、複数のＢは同一でも異なっていてもよい。
各式中のＲ、上記Ａ中のＲ及び上記Ｂ中のＲは、それぞれ、水素原子又は置換基を表し、水素原子が好ましい。Ｒとして採りうる置換基としては、特に限定されないが、好ましくは、上記置換基群Ｔから選択される。より好ましい置換基としては、後述する「置換基群Ｔから選ばれるより好ましい基」が挙げられる。各式中、Ｒが複数存在する場合、複数のＲは同一でも異なっていてもよい。
ｎは０〜４の整数であり、好ましくは０〜３の整数であり、より好ましくは０又は１である。

In formula (H-2) to formula (H-7), A represents a sulfur atom, an oxygen atom, a selenium atom, NR, SiR ₂ or CR ₂ . Among them, NR, CR ₂ or sulfur atom is preferable. In each formula, when a plurality of A are present, the plurality of A may be the same or different.
B represents CR or a nitrogen atom. In each formula, when a plurality of B are present, the plurality of B may be the same or different.
R in each formula, R in A and R in B each represent a hydrogen atom or a substituent, and a hydrogen atom is preferred. The substituent that can be taken as R is not particularly limited, but is preferably selected from the above substituent group T. More preferable substituents include “a more preferable group selected from substituent group T” described later. In each formula, when a plurality of Rs are present, the plurality of Rs may be the same or different.
n is an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably 0 or 1.

式（Ｈ−８）〜式（Ｈ−１１）中、Ｚ^ａ〜Ｚ^ｈは、炭素原子、窒素原子、酸素原子、硫黄原子、リン原子、セレン原子及びケイ素原子から選ばれる、環を形成しうる非金属原子群を示す。Ｚ^ａ〜Ｚ^ｈが各式中の炭素原子とともに形成する環としては、特に限定されないが、５員環若しくは６員環又はこれらを含む縮環が挙げられる。形成される環としては、上記置換基群Ｔにおけるアリール基又はヘテロアリール基が挙げられる。中でも、ベンゼン環、フルオレン環、カルバゾール環、ピリジン環、チオフェン環、ジチオフェン環、ピロール環、フラン環、チアゾール環、オキサゾール環、イミダゾール環、ベンゾチオフェン環、ベンゾフラン環等が好ましい。
Ｚ^ａ及びＺ^ｂ、Ｚ^ｃ及びＺ^ｄ、Ｚ^ｅ及びＺ^ｆ、並びに、Ｚ^ｇ及びＺ^ｈは、それぞれ、同一でも異なっていてもよい。
Ｚ^ａ〜Ｚ^ｈが形成する環は置換基を有していてもよい。これらの環が有していてもよい置換基としては、特に限定されないが、好ましくは、上記置換基群Ｔから選択される。より好ましい置換基としては、後述する「置換基群Ｔから選ばれるより好ましい基」が挙げられる。これらの環が複数の置換基を有する場合、複数の置換基は同一でも異なっていてもよい。
各式中のＲは水素原子又は置換基を表し、水素原子が好ましい。Ｒとして採りうる置換基としては、特に限定されないが、好ましくは、上記置換基群Ｔから選択される。より好ましい置換基としては、後述する「置換基群Ｔから選ばれるより好ましい基」が挙げられる。各式中、Ｒが複数存在する場合、複数のＲは同一でも異なっていてもよい。
ｎは０〜４の整数である。式（Ｈ−８）〜式（Ｈ−１０）中のｎは、好ましくは１〜３の整数であり、より好ましくは１である。式（Ｈ−１１）中のｎは、好ましくは０〜３の整数であり、より好ましくは０又は１である。

In formula (H-8) to formula (H-11), Z ^{a to} Z ^h form a ring selected from a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a selenium atom and a silicon atom. Non-metallic atom group Z As the ^{ring a} to Z ^h is formed together with the carbon atoms in each formula is not particularly limited, and a 5- or 6-membered ring or condensed ring containing them. Examples of the ring formed include an aryl group or a heteroaryl group in the above substituent group T. Of these, benzene ring, fluorene ring, carbazole ring, pyridine ring, thiophene ring, dithiophene ring, pyrrole ring, furan ring, thiazole ring, oxazole ring, imidazole ring, benzothiophene ring, benzofuran ring and the like are preferable.
Z ^a and Z ^b , Z ^c and Z ^d , Z ^e and Z ^f , and Z ^g and Z ^h may be the same as or different from each other.
The ring formed by Z ^{a to} Z ^h may have a substituent. The substituent that these rings may have is not particularly limited, but is preferably selected from the above substituent group T. More preferable substituents include “a more preferable group selected from substituent group T” described later. When these rings have a plurality of substituents, the plurality of substituents may be the same or different.
R in each formula represents a hydrogen atom or a substituent, and a hydrogen atom is preferable. The substituent that can be taken as R is not particularly limited, but is preferably selected from the above substituent group T. More preferable substituents include “a more preferable group selected from substituent group T” described later. In each formula, when a plurality of Rs are present, the plurality of Rs may be the same or different.
n is an integer of 0-4. N in Formula (H-8) to Formula (H-10) is preferably an integer of 1 to 3, and more preferably 1. N in the formula (H-11) is preferably an integer of 0 to 3, more preferably 0 or 1.

式（Ｈ−１２）中、Ｄは二つ以上の環が縮環した構造を表す。
Ｄは上記構造であれば特に限定されず、例えば、下記式（Ｄ−１）又は式（Ｄ−２）で表される構造が挙げられる。

In formula (H-12), D represents a structure in which two or more rings are condensed.
If D is the said structure, it will not specifically limit, For example, the structure represented by a following formula (D-1) or a formula (D-2) is mentioned.

式（Ｄ−１）及び式（Ｄ−２）中、＊は、Ｌ^１、Ｌ^２、Ａ^１、Ａ^２又はＤとの結合部位を表す。
Ｘ^１〜Ｘ^４は、硫黄原子、酸素原子、セレン原子、ＮＲ、ＳｉＲ_２又はＣＲ_２を表す。中でも、硫黄原子又はＮＲが好ましい。Ｘ^１とＸ^２、及び、Ｘ^３とＸ^４とは、それぞれ、同一でも異なっていてもよい。Ｚ^１〜Ｚ^４は、窒素原子又はＣＲを表す。Ｚ^１とＺ^２、及び、Ｚ^３とＺ^４とは、それぞれ、同一でも異なっていてもよい。Ｒは水素原子又は置換基を表し、水素原子が好ましい。Ｘ^１〜Ｘ^４及びＺ^１〜Ｚ^４中のＲとして採りうる置換基としては、特に限定されないが、好ましくは、上記置換基群Ｔから選択される。より好ましい置換基としては、後述する「置換基群Ｔから選ばれるより好ましい基」が挙げられる。各式中、Ｒが複数存在する場合、複数のＲは同一でも異なっていてもよい。
環Ａ及び環Ｂは、環構造を表し、各式中の２つの５員環と縮合している。
環Ａ及び環Ｂとして採りうる環構造としては、特に限定されず、脂肪族環でもよいが芳香族環が好ましい。この環構造は、単環でも縮合環でもよく、例えば、上記置換基群Ｔにおけるアリール基若しくはヘテロアリール基を形成する環、又は、これらの環を２つ以上縮合してなる縮合環が挙げられる。中でも、ベンゼン環、ナフタレン環、アントラセン環等が好ましい。

In formula (D-1) and formula (D-2), * represents a binding site with L ¹ , L ² , A ¹ , A ² or D.
X ¹ to X ⁴ represents sulfur atom, oxygen atom, selenium atom, NR, a SiR _2, or CR _2. Among these, a sulfur atom or NR is preferable. X ¹ and X ² , and X ³ and X ⁴ may be the same or different from each other. Z ^{1 to} Z ⁴ represent a nitrogen atom or CR. Z ¹ and Z ² , and Z ³ and Z ⁴ may be the same as or different from each other. R represents a hydrogen atom or a substituent, and preferably a hydrogen atom. The substituents can take as R of X ¹ to X ⁴ and ^Z 1 to Z ⁴ is not particularly limited, preferably selected from the substituent group T. More preferable substituents include “a more preferable group selected from substituent group T” described later. In each formula, when a plurality of Rs are present, the plurality of Rs may be the same or different.
Ring A and ring B represent a ring structure and are fused with two 5-membered rings in each formula.
The ring structure that can be adopted as ring A and ring B is not particularly limited, and may be an aliphatic ring, but is preferably an aromatic ring. This ring structure may be a single ring or a condensed ring, and examples thereof include a ring forming an aryl group or a heteroaryl group in the substituent group T, or a condensed ring formed by condensing two or more of these rings. . Of these, a benzene ring, a naphthalene ring, an anthracene ring and the like are preferable.

In Formula (H-12), L ¹ and L ² represent a single bond or a linking group. The linking group is not particularly limited, and examples thereof include an alkenylene group, an alkynylene group, an arylene group, and a heteroarylene group. L ¹ and L ² may be the same or different. When L ¹ and L ² take a linking group, the linking group is not limited to one, and a linking group in which two or more are bonded can also be taken. For example, a linking group made of terthiophene can be mentioned.
A ¹ and A ² represent a heterocyclic ring, a hydrocarbon ring, or a group having acceptor properties.
The heterocyclic ring may be an aliphatic ring or an aromatic ring, and may be a monocyclic ring or a condensed ring. For example, as the aromatic heterocyclic ring, one or more of a ring forming a heteroaryl group in the above substituent group T, a condensed ring formed by condensing two or more of these rings, or a ring forming a heteroaryl group And a condensed ring formed by condensing the ring forming the aryl group in the substituent group T. Although it does not specifically limit as an aliphatic heterocyclic ring, Among the heterocyclic rings in the substituent group T, an aliphatic heterocyclic ring, a condensed ring in which two or more of these are condensed, or one or more aliphatic heterocyclic rings and a substituent The condensed ring which the aryl group in group T condensed is mentioned. The heterocycle is preferably an aromatic heterocycle, and examples thereof include a thiophene ring, a furan ring, a pyrrole ring, a thiazole ring, an oxazole ring, an imidazole ring, a pyridine ring, a benzothiophene ring, a benzofuran ring, and a benzopyrrole ring.
The hydrocarbon ring may be an aliphatic ring or an aromatic ring, and may be a single ring or a condensed ring. For example, examples of the hydrocarbon ring include a ring forming an aryl group in the substituent group T or a condensed ring formed by condensing two or more of these rings. Examples of the hydrocarbon ring include a benzene ring.

The group having an acceptor property means a group having an electron-withdrawing group. Here, the electron withdrawing group refers to a group having a property of reducing the electron density of the above-mentioned D, L ¹ or L ² or a binding site thereof by an inducing effect and / or a mesomeric effect.
As group which has acceptor property, if the said characteristic is shown, it will not specifically limit, For example, group represented by a following formula (A-1) or a formula (A-2) is mentioned.

式（Ａ−１）及び式（Ａ−２）中、Ｙ^１は、酸素原子、硫黄原子又はＮＲ^Ａ１を表す。
Ｒ^Ａ１〜Ｒ^Ａ４は水素原子又は置換基を表す。但し、Ｒ^Ａ３及びＲ^Ａ４のうち少なくとも一方は電子求引性基を表す。電子求引性基としては、上記性質を有するものであれば特に限定されず、例えば、上記式（Ａ−１）で表される基、ニトロ基、シアノ基、スルホニル基、ホスホリル基、アジド基（−Ｎ_３）、アンモニウム基（−Ｎ^＋（Ｒ^Ｎ１）（Ｒ^Ｎ２）（Ｒ^Ｎ３））、イミニウム基（−Ｃ（Ｒ^Ｎ４）＝Ｎ（Ｎ（Ｒ^Ｎ５）（Ｒ^Ｎ６））又はハロゲン原子等が挙げられる。ここで、Ｒ^Ｎ１〜Ｒ^Ｎ６は、いずれも、水素原子、又は上記置換基群Ｔから選択される置換基を示す。
Ｒ^Ａ１〜Ｒ^Ａ４として採りうる置換基としては、特に限定されないが、好ましくは、上記置換基群Ｔから選択される。より好ましい置換基としては、後述する「置換基群Ｔから選ばれるより好ましい基」が挙げられる。Ｒ^Ａ１とＲ^Ａ２、及び、Ｒ^Ａ３とＲ^Ａ４は、同一でも異なっていてもよい。
Ｒ^Ａ１〜Ｒ^Ａ４は、互いに結合して環を形成していてもよく、また、環を構成する少なくとも１つの−ＣＨ_２−が不飽和結合形成原子で置換されていてもよい。このような不飽和結合形成原子で置換された環を有する、式（Ａ−２）で表される基としては、好ましくは、実施例で用いた正孔輸送材料Ｓ１のチアゾリジン環を含む基が挙げられる。また、Ｒ^Ａ１〜Ｒ^Ａ４として採りうる置換基は、それぞれ更に置換基を有していてもよい。Ｒ^Ａ１〜Ｒ^Ａ４が更に有していてもよい置換基としては、特に限定されず、Ｒ^Ａ１として採りうる置換基と同義であり、好ましいものも同じである。

In formula (A-1) and formula (A-2), Y ¹ represents an oxygen atom, a sulfur atom or NR ^A1 .
R ^{A1 to} R ^A4 represent a hydrogen atom or a substituent. However, at least one of R ^A3 and R ^A4 represents an electron withdrawing group. The electron-attracting group is not particularly limited as long as it has the above properties, and examples thereof include a group represented by the above formula (A-1), a nitro group, a cyano group, a sulfonyl group, a phosphoryl group, and an azide group. (—N ₃ ), ammonium group (—N ⁺ (R ^N1 ) (R ^N2 ) (R ^N3 )), iminium group (—C (R ^N4 ) = N (N (R ^N5 ) (R ^N6 )) or halogen Atoms, etc. Here, R ^{N1 to} R ^N6 each represents a hydrogen atom or a substituent selected from the above substituent group T.
Although it does not specifically limit as a substituent which can be taken as R < ^A1 > -R < ^A4 >, Preferably, it selects from the said substituent group T. FIG. More preferable substituents include “a more preferable group selected from substituent group T” described later. R ^A1 and R ^A2 and R ^A3 and R ^A4 may be the same or different.
R ^{A1 to} R ^A4 may be bonded to each other to form a ring, and at least one —CH ₂ — constituting the ring may be substituted with an unsaturated bond-forming atom. The group represented by the formula (A-2) having a ring substituted with such an unsaturated bond-forming atom is preferably a group containing a thiazolidine ring of the hole transport material S1 used in the examples. Can be mentioned. Moreover, the substituent which can be taken as R ^{A1 to} R ^A4 may further have a substituent. The substituent that R ^{A1 to} R ^A4 may further have is not particularly limited and has the same meaning as the substituent that can be adopted as R ^A1 .

  In Formula (H-12), n represents an integer of 1 to 4, preferably an integer of 1 to 2, and more preferably 1. When n represents an integer of 2 to 4, a plurality of D may be the same or different.

  As the hole transport material, 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, spiro-OMeTAD, hole transport material represented by the above formula (H-1)), poly (3-hexylthiophene-2,5-diyl), 4- (diethylamino) benzaldehyde diphenylhydrazone, poly (3,4-ethylenedioxythiophene) (poly (3,4-ethylenedioxythiophene), PEDOT), poly [bis ( 4-phenyl) (2,4,6-trimethylphenyl) a ine] (PTAA), 2,6-Diethylbenzo [1,2-b: 4,5-b ′] dithiophene (DT-BDT, hole transport material represented by the above formula (H-8)), 2, 7-Dioctyl [1] benzothieno [3,2-b] [1] benzothiophene (C8-BTBT, hole transport material represented by the above formula (H-5)), 6,13-Bis (triisopropylsilylyl) pentacene ( TIPS pentacene, a hole transport material represented by the above formula (H-8), and the like.

  The hole transport material may be appropriately synthesized according to a known method, for example, a method shown in Examples described later, or a commercially available product may be used.

  The thickness of the hole transport layer 3 is not particularly limited, but is preferably 50 μm or less, more preferably 1 nm to 10 μm, still more preferably 5 nm to 5 μm, particularly preferably 10 nm to 1 μm, and most preferably 10 to 50 nm.

<Electron transport layer 4>
It is also one of the preferable aspects that the photoelectric conversion element of this invention has the electron carrying layer 4 between the 1st electrode 1 and the 2nd electrode 2 like the photoelectric conversion element 10E. In this embodiment, the electron transport layer 4 is preferably in contact (laminated) with the photosensitive layer 3C.
The electron transport layer 4 is the same as the electron transport layer 15 except that the electron transport destination is the second electrode and the position where the electron transport layer 4 is formed is different.

<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 etc. are 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.

Examples of the material for forming the second electrode 2 include platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium ( Examples thereof include metals such as Pd), rhodium (Rh), iridium (Ir), osnium (Os), and aluminum (Al), 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 plastic substrate having this thin film. As the glass substrate or plastic substrate, glass having a gold or platinum thin film or glass on which platinum is vapor-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 still 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 or the like.
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. 1 to FIG. 5, a photoelectric conversion element 10 configured to work on the external circuit 6 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 disclosed in, for example, Patent Documents 1 and 2, J. Pat. Am. Chem. Soc. 2009, 131 (17), p. 6050-6051 and Science, 338, p. 643 (2
It can be applied to each solar cell described in 012).
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.

[Production Method of Photoelectric Conversion Element and Solar Cell]
The photoelectric conversion element and solar cell of the present invention are prepared by a known production method, for example, Patent Documents 1 and 2, J. Pat. Am. Chem. Soc. 2009, 131 (17), p. 6050-6051, Science, 338, p. 643 (2012) or the like.
The photoelectric conversion element of the present invention is a photoelectric conversion element of the present invention having a step of providing a polycyclic compound-containing layer on a conductive support and a step of providing a hole transport layer on the surface of the polycyclic compound-containing layer. It is preferable to manufacture by a manufacturing method. The method for producing a photoelectric conversion element of the present invention can produce a photoelectric conversion element having any one of the layer structure of the first aspect and the layer structure of the second aspect.
In the method for producing a photoelectric conversion element of the present invention, providing a polycyclic compound-containing layer on a conductive support is a mode in which a polycyclic compound-containing layer is provided (directly provided) in contact with the surface of the conductive support, and In addition, it is meant to include a mode in which a polycyclic compound-containing layer is provided via another layer above the surface of the conductive support.
In an embodiment having a polycyclic compound-containing layer via another layer above the surface of the conductive support, the other layer provided between the conductive support and the polycyclic compound-containing layer is a solar battery. There is no particular limitation as long as it does not reduce the performance. Examples thereof include a porous layer, a blocking layer, an electron transport layer, a hole transport layer, and a photosensitive layer.

Below, the manufacturing method of the photoelectric conversion element of this invention and the manufacturing method of a solar cell are demonstrated easily.
In the photoelectric conversion element of the present invention having the laminated structure of the layer structure of the first aspect, first, if desired, on the surface of the conductive support 11, a blocking layer 14, a porous layer 12, an electron transport layer 15, and a hole transport. At least one of the layers 16 is formed.
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, firing 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 or the hole transport layer 16 is provided, it can be formed in the same manner as the hole transport layer 3 or the electron transport layer 4 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 composition (solution) containing a perovskite type light absorbent is preferred. In this method, first, a light absorbent composition for forming a photosensitive layer is prepared. The light absorber composition 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 composition, 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 composition 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. The heating conditions are not particularly limited, but 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, and more preferably 1 to 3 hours. As the solvent or dispersion medium, those described later can be used.
Next, the prepared light absorber composition is brought into contact with the surface of the layer (any one of the porous layer 12, the blocking layer 14, or the electron transport layer 15) that forms the photosensitive layer 13 on the surface thereof. Specifically, it is preferable to apply or immerse the light absorbent composition. 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 composition, drying by heat is preferable and it is normally dried by heating to 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, AX compositions containing the AX and (ammonium salt composition), MX ₂ compositions containing the MX ₂ and (metal salt composition), was separately coated (including dipping method), if necessary The method of drying is also mentioned. In this method, any solution may be applied first, but preferably the MX ₂ composition 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 composition and the MX ₂ composition.

Yet another method includes a dry method such as vacuum deposition using a compound or mixture from which the solvent of the light absorber composition has been removed. For example, the AX and the MX _2, simultaneously or sequentially, and a method of depositing.
By these methods, a 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 polycyclic compound-containing layer 5 is formed on the surface of the photosensitive layer 13 thus provided, that is, on the conductive support.

In order to form the polycyclic compound-containing layer 5, a composition for a photoelectric conversion element containing a polycyclic compound is prepared. A polycyclic compound is as above-mentioned, and can use 1 type (s) or 2 or more types.
When the polycyclic compound-containing layer 5 contains a polycyclic compound having at least two groups selected from the following group G3, the composition for a photoelectric conversion element of the present invention described later can be preferably used.
[Group G3] —NR ^a R ^b and —P (═O) (OR ^a ) ₂ (R ^a and R ^b are as described above.)

The composition for photoelectric conversion elements contains a solvent. Although it does not specifically limit as a solvent, Although the solvent or dispersing agent mentioned later is mentioned, It is preferable that an aprotic solvent is included.
The aprotic solvent is not particularly limited as long as it does not have active hydrogen. For example, in addition to a hydrocarbon solvent, a halogen solvent, a nitrile solvent, and the like described later, an ether solvent, a ketone solvent, and the like can be given. Among these, a hydrocarbon solvent or a halogen solvent is preferable, and a halogen solvent is more preferable. Examples of the hydrocarbon solvent include benzene, toluene, xylene and the like. Examples of the halogen solvent include chlorobenzene, chloroform, benzyl chloride, dichloromethane and the like.
In the composition for a photoelectric conversion element, the aprotic solvent and the alcohol solvent can be used in combination in terms of the solubility of the polycyclic compound and the applicability to the coated surface. Examples of the alcohol solvent include t-butanol, octanol and the like in addition to methanol, ethanol and isopropanol described later. The combination of the aprotic solvent and the alcohol solvent is not particularly limited, and examples thereof include a combination of mutually preferable ones.
When the composition for photoelectric conversion elements contains a polycyclic compound having at least two groups selected from the group G3 and an aprotic solvent, the composition for photoelectric conversion elements is used as the photoelectric conversion element of the present invention. It is called a composition.

The content of the polycyclic compound in the composition for photoelectric conversion elements is not particularly limited, and is preferably, for example, 10 mmol / L or less, more preferably 0.01 to 10 mmol / L, and more preferably 1 to 10 mmol / L. Is more preferable.
Content of the aprotic solvent in the composition for photoelectric conversion elements is not specifically limited, For example, it exceeds 0 mass%, 100 mass% or less is preferable, 50-99 mass% is more preferable, 80-95 More preferred is mass%.
Content of the alcohol solvent in the composition for photoelectric conversion elements is not specifically limited, For example, 0-100 mass% is preferable, 1-50 mass% is more preferable, 5-20 mass% is still more preferable.
When the composition for photoelectric conversion elements contains an alcohol solvent, the ratio of the content of the aprotic solvent to the alcohol solvent in the composition for photoelectric conversion elements [aprotic solvent / alcohol solvent] Although it will not specifically limit as long as content of is satisfy | filled, For example, it is preferable that it is 50 / 50-99 / 1, and it is more preferable that it is 80 / 20-95 / 5.

Subsequently, the polycyclic compound content layer 5 is formed using the prepared composition for photoelectric conversion elements. Examples of the method for forming the polycyclic compound-containing layer 5 include a method in which the composition for a photoelectric conversion element and the photosensitive layer 13 are brought into contact with each other. The method of bringing them into contact is the same as the method of providing the photosensitive layer 13, and the preferred method is also the same. It is preferable to apply or immerse the photoelectric conversion element composition in the photosensitive layer 13. The temperature to contact is not specifically limited, It is preferable that it is 0-150 degreeC, and it is more preferable that it is 15-50 degreeC. The immersion time is also not particularly limited, and is preferably 0.1 second to 24 hours, more preferably 5 seconds to 1 hour. When drying the composition for photoelectric conversion elements, drying by heat is preferable, and drying is usually performed by heating to 30 to 200 ° C, preferably 40 to 110 ° C.
Thus, the process of providing a polycyclic compound containing layer is performed, and the polycyclic compound containing layer 5 adjacent to the photosensitive layer 13 is formed.

Next, the hole transport layer 3 is formed on the surface of the polycyclic compound-containing layer 5.
The hole transport layer 3 can be formed by applying (contacting) a hole transport material solution containing a hole transport material and drying. The concentration of the hole transport material is 0.1 to 1.0 M in that the hole transport material solution is excellent in applicability and easily penetrates into the pores of the porous layer 12 when the porous layer 12 is provided. (Mol / L) is preferred. The temperature to apply is not specifically limited, It is preferable that it is 0-150 degreeC, and it is more preferable that it is 15-50 degreeC. The coating time is also not particularly limited, and is preferably 1 second to 24 hours, more preferably 10 seconds to 1 hour. When the hole transport material solution is dried, the drying is preferably performed by heating, and is usually performed by heating to 30 to 200 ° C, preferably 40 to 110 ° C.
In this way, the step of providing the hole transport layer 3 is performed, and the hole transport layer 3 adjacent to the polycyclic compound-containing layer 5 is formed. When a hole transport material solution is formed on the surface of the polycyclic compound-containing layer 5, as described above, the internal loss of the element can be reduced, and further, the orientation of the hole transport material, the hole transport layer and the polycyclic compound are contained. It is thought that the interface state with the layer can be modified.

  After the hole transport layer 3 is formed, the second electrode 2 is formed, and a photoelectric conversion element having the laminated structure of the layer structure of the first aspect is manufactured.

In the photoelectric conversion element of the present invention having the laminated structure of the layer structure of the second aspect, first, the polycyclic compound-containing layer 5C is formed on the surface of the conductive support 11. The method for forming the polycyclic compound-containing layer 5C is the same as the method for forming the polycyclic compound-containing layer 5.
Next, the hole transport layer 16 and the photosensitive layer 13C are sequentially formed on the surface of the polycyclic compound-containing layer 5C. The method for forming the hole transport layer 16 and the photosensitive layer 13C is as described above. In this way, the step of providing the polycyclic compound-containing layer 5C and the step of providing the hole transport layer 16 on the surface of the polycyclic compound-containing layer 5C are performed, and the polycyclic compound-containing layer 5C, the hole transport layer 16 and the photosensitive layer are performed. A layer structure of the second embodiment in which 13C is adjacent to each other is formed. Thereby, as described above, the internal loss of the element can be reduced, and further, the orientation of the hole transport material and the interface state between the hole transport layer and the polycyclic compound-containing layer can be modified.
Next, if necessary, the electron transport layer 4 and the second electrode 2 are formed on the photosensitive layer 13C, and a photoelectric conversion element having a layered structure of the layer structure of the second aspect is manufactured.

  In the method for producing a photoelectric conversion element, the film thickness of each layer can be adjusted by appropriately changing the concentration of each dispersion or composition (solution) and the number of coatings. For example, when the thick photosensitive layers 13B and 13C are provided, the light absorber composition, the ammonium salt composition or the metal salt composition may be applied and dried a plurality of times.

  Each of the above-mentioned dispersions and compositions may contain additives such as a dispersion aid and a surfactant as 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 (DMF), dimethylacetamide, or a mixed solvent thereof is preferable.

  The coating method of the composition 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, A known coating method such as an inkjet printing method or a dipping method can be used. Of these, spin coating and screen printing are preferred.

  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.

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

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

[Production of Photoelectric Conversion Element (Sample No. 101)]
<Preparation 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 mass% isopropanol solution of titanium diisopropoxide bis (acetylacetonate) (manufactured by Aldrich) was diluted with 1-butanol to prepare a 0.02 M (mol / L) 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, a sintered body of titanium oxide obtained, after immersion in TiCl ₄ aqueous solution of 40 mM, and heated for 1 hour at 60 ° C., and heated followed by at 500 ° C. 30 minutes, the porous layer 12 made of TiO ₂ ( A film thickness of 250 nm) was formed.

<Preparation of light absorber solution A>
A 40 mass% methanol solution (27.86 mL) of methylamine and an aqueous solution of 57 mass% hydrogen iodide (hydroiodic acid, 30 mL) were stirred in a flask at 0 ° C. for 2 hours, and then concentrated. A crude product of CH ₃ NH ₃ I was obtained. The obtained crude product of CH ₃ NH ₃ I was dissolved in ethanol and recrystallized from diethyl ether. The precipitated crystals were collected by filtration and dried under reduced pressure at 60 ° C. for 5 hours to obtain purified CH ₃ NH ₃ I.
Subsequently, purified CH ₃ NH ₃ I and PbI ₂ were mixed at a molar ratio of 3: 1 with stirring in DMF at 60 ° C. for 12 hours, and then filtered through a polytetrafluoroethylene (PTFE) syringe filter to obtain 40% by mass. A light absorber solution A was prepared.
<Formation of photosensitive layer 13A>
The prepared light absorber solution A is applied to the porous layer 12 formed on the conductive support 11 by spin coating (application speed: 60 ° C. for 60 seconds), and then the applied light absorption is applied. The agent solution A was dried on a hot plate at 100 ° C. for 60 minutes to provide a photosensitive layer 13A (thickness 300 nm (including the thickness 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.

<Preparation of composition A1 for photoelectric conversion elements>
The polycyclic compound a1 (2.9 mg, 5 mmol) was dissolved in benzyl chloride (2 mL), and the insoluble matter was filtered with a polytetrafluoroethylene (PTFE) syringe filter to prepare a composition A1 for a photoelectric conversion element. .
<Formation of polycyclic compound-containing layer 5A>
Subsequently, the composition A1 for photoelectric conversion elements was apply | coated to the surface (25 mm x 25 mm) of the 1st electrode by the spin coat method (1000 rpm for 30 seconds). Next, the applied composition A1 for photoelectric conversion elements was dried at 100 ° C. for 30 minutes using a hot plate. Thus, a polycyclic compound-containing layer 5A (film thickness is shown in Table 1) was formed.

<Preparation of hole transport material solution H1>
As a hole transport material, S1 (20 mg) shown below was dissolved in chloroform (1 mL) to prepare a hole transport layer solution H1. This hole transport material S1 is a hole transport material represented by the above formula (H-12), and is disclosed in Chinese Patent Application No. 105218558 (CN105218558A) and Journal of the American Chemical Society, 2013, vol. . 135, no. 23, p. Synthesized with reference to 8484 etc.
<Formation of hole transport layer 3A>
Next, on the polycyclic compound-containing layer 5A formed on the surface of the first electrode 1A, the prepared hole transport layer solution H1 is applied by a spin coat method and dried (at 60 ° C. for 30 minutes) to obtain a solid state. Hole transport layer 3A (film thickness is shown in Table 1).

<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, photoelectric conversion element 10A (sample No. 101) was manufactured.
Each film thickness was observed and measured with a scanning electron microscope (SEM) (the same applies to Examples 2 to 4).

[Production of Photoelectric Conversion Element (Sample Nos. 102 to 122)]
Sample No. mentioned above. In the production of the photoelectric conversion element 10A of No. 101, as shown in Table 1, sample No. 1 was changed except that the polycyclic compound, the thickness of the polycyclic compound-containing layer, and the thickness of the hole transport layer were changed. In the same manner as in the manufacture of the photoelectric conversion element 10A of 101, the sample No. 10A of photoelectric conversion elements 102A-122 were manufactured, respectively.
Specifically, the film thickness of the polycyclic compound-containing layer was changed by adjusting the content (concentration) of the polycyclic compound in the photoelectric conversion element composition A1 within a range of 0.1 to 50 mM. . Further, the film thickness of the hole transport layer 3A was specifically changed by adjusting the coating conditions (rotation speed) by a spin coating method.

[Production of Photoelectric Conversion Elements (Sample Nos. C101 to c105)]
Sample No. mentioned above. In the manufacture of the photoelectric conversion element 10A of No. 101, as shown in Table 1, sample No. In the same manner as in the manufacture of the photoelectric conversion element 10A of 101, the sample No. 10A of photoelectric conversion elements c101 to c105 were manufactured.
In Table 1, “-” in the “Polycyclic Compound” column means that no polycyclic compound is used, and “-” in the “Film Thickness” column indicates that no polycyclic compound-containing layer is formed. (Meaning the same in Tables 2 to 4).
The polycyclic compounds used are shown below (SS1 is not a polycyclic compound but is referred to as a polycyclic compound for convenience). In SS2 below, Bu represents butyl.

[Evaluation of photoelectric conversion element]
Each sample No. With respect to the photoelectric conversion element, a battery characteristic test was conducted to determine a fill factor (FF). The results are shown in the “FF” column of Table 1.
The battery characteristic test irradiates each photoelectric conversion element with 1000 W / m ² pseudo-sunlight from a xenon lamp through an AM1.5G filter using a solar simulator “PEC-L15” (manufactured by Pexel Technologies). Was done. Fill factor (FF) was calculated | required by measuring the current-voltage characteristic of each photoelectric conversion element which irradiated the artificial sunlight using source meter "Keithley2401" (made by Tektronix). From the obtained current-voltage characteristics, an open circuit voltage V _OC , a short-circuit current value J _SC , and maximum output points (I _max and V _max ) are obtained, and the formula: FF = (I _max × V _max ) / (V _OC × J _SC ).
Next, sample No. The relative value (fill factor (FF) / (FF _c101 ) of the photoelectric conversion element of each sample No.) with respect to the fill factor (FF _c101 ) of the photoelectric conversion element of _c101 was determined.
It was determined which of the following evaluation criteria the relative value was included.
In this evaluation, an evaluation rank “E” or higher is practically required, and an evaluation rank “D” or higher is preferable.
− Evaluation criteria −
A: 1.05 or more B: 1.04 or more and less than 1.05 C: 1.03 or more and less than 1.04 D: 1.02 or more and less than 1.03 E: 1.01 or more and less than 1.02 F: 1. 00 or more and less than 1.01 G: Less than 1.00

From the results in Table 1, the following can be understood.
Sample No. which does not include the polycyclic compound-containing layer defined in the present invention. None of the photoelectric conversion elements c102 to c105 had a sufficient fill factor. That is, even if the compound SS1 having a monocyclic structure or the compound SS2 not having the specific polycyclic structure defined in the present invention has two groups G, the effect of improving the fill factor is not sufficient. Moreover, even if it has the specific polycyclic structure prescribed | regulated by this invention, if it does not have group G (sample No. c105), a high fill factor is also not shown. In addition, even when the compound SS3 that does not satisfy both the polycyclic structure and the group G defined in the present invention is used, the effect of improving the fill factor is not exhibited.
On the other hand, Sample No. provided with a polycyclic compound-containing layer defined in the present invention. The photoelectric conversion elements 101 to 122 all exhibit a high fill factor. In particular, a polycyclic compound having a partial structure represented by the formula (BS-1) or the formula (BS-5), and —NR ^a R ^b or —P (═O) (OR ^a ) ₂ as the group G Any of the polycyclic compounds possessed has a high improvement effect on the fill factor. When a polycyclic compound-containing layer containing a polycyclic compound defined in the present invention and having a film thickness of 1 to 10 nm is provided, or a polycyclic compound-containing layer defined in the present invention and a positive film thickness of 10 to 50 nm. When provided in combination with the hole transport layer, the photoelectric conversion element exhibits a high fill factor.

Example 2
In Example 2 (2-1 to 2-4), a photoelectric conversion element having a photosensitive layer in which a perovskite compound was changed was produced, and its characteristics were evaluated.

Example 2-1
[Production of Photoelectric Conversion Elements (Sample Nos. 201 and c201)]
Sample No. 1 in Example 1 In the production of the photoelectric conversion element 10A of No. 114, the photosensitive layer 13A is formed by the following method using the following light absorbent solution B instead of the light absorbent solution A, For sample c201, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion element 10A of 201 and c201 was manufactured, respectively.
<Preparation of light absorber solution B>
Cesium iodide (39 mg), formamidine hydroiodide (Formamidine Hydroide, 516 mg), CH ₃ NH ₃ Br (67 mg) and lead iodide (1.73 g) were mixed with DMF and DMSO (dimethyl sulfoxide). A light absorber solution B was prepared by dissolving in a solvent (DMF / DMSO = 4/1 (volume ratio)).
<Formation of photosensitive layer 13A>
The prepared light absorbent solution B was applied on the porous layer 12 formed on the conductive support 11 by spin coating (5000 rpm, 50 seconds). Moreover, chlorobenzene (500 microliters) was sprayed on the coating layer surface with the pipetter during application | coating. Thereafter, the applied light absorber solution B was dried at 100 ° C. for 60 minutes by a hot plate to obtain a perovskite compound of Cs _0.04 FA _0.8 (CH ₃ NH ₃ ) _0.16 PbI _2.84 Br _0.16 . A photosensitive layer 13A (having a thickness of 300 nm (including a thickness of 250 nm of the porous layer 12)) was provided.
The chemical formula of the perovskite compound and “FA” in the “photosensitive layer” column of Table 2 represent a formamidino group (—C (═NH) NH ₂ ) (the same applies hereinafter).

Example 2-2
[Production of Photoelectric Conversion Element (Sample Nos. 202 and c202)]
Sample No. 1 in Example 1 In the production of the photoelectric conversion element 10A of No. 114, the photosensitive layer 13A is formed by the following method using the following light absorbent solution C instead of the light absorbent solution A. For sample c202, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion elements 10A of 202 and c202 were manufactured.
<Preparation of light absorber solution C>
A 40 mass% methanol solution (27.86 mL) of methylamine and an aqueous solution of 57 mass% hydrogen iodide (hydroiodic acid, 30 mL) were stirred in a flask at 0 ° C. for 2 hours, and then concentrated. A crude product of CH ₃ NH ₃ I was obtained. The obtained crude product of CH ₃ NH ₃ I was dissolved in ethanol and recrystallized from diethyl ether. The precipitated crystals were collected by filtration and dried under reduced pressure at 60 ° C. for 5 hours to obtain purified CH ₃ NH ₃ I. Subsequently, after purifying CH ₃ NH ₃ I, PbI ₂ and SnI ₂ in a molar ratio of 3: 0.9: 0.1, stirring and mixing in DMF at 60 ° C. for 12 hours, a polytetrafluoroethylene (PTFE) syringe filter To prepare a 40 mass% light absorber solution C.
<Formation of photosensitive layer 13A>
The prepared light absorber solution C was applied (application temperature: 60 ° C.) onto the porous layer 12 formed on the conductive support 11 by spin coating (application speed: 60 ° C.), and then applied light absorption. The agent solution C was dried on a hot plate at 100 ° C. for 60 minutes to form a photosensitive layer 13A (thickness 300 nm (thickness of the porous layer 12) of a perovskite compound of CH ₃ NH ₃ Pb _0.9 Sn _0.1 I ₃ Including 250 nm)).

Example 2-3
[Production of Photoelectric Conversion Elements (Sample Nos. 203 and c203)]
Sample No. 1 in Example 1 In the production of the photoelectric conversion element 10A of No. 114, the photosensitive layer 13A is formed by the following method using the following light absorbent solution D instead of the light absorbent solution A, For sample c203, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion elements 10A of 203 and c203 were manufactured.
<Preparation of light absorber solution D>
Formamide Hydroide and PbI ₂ were mixed at a molar ratio of 1: 1 in DMF with stirring at 60 ° C. for 12 hours, and then filtered through a polytetrafluoroethylene (PTFE) syringe filter to obtain a 40% by mass of a light absorbent solution D Was prepared.
<Formation of photosensitive layer 13A>
The prepared light absorber solution D is applied (application temperature: 60 ° C.) on the porous layer 12 formed on the conductive support 11 by spin coating (at 2000 rpm for 60 seconds), and then applied light absorption. The agent solution D was dried on a hot plate at 100 ° C. for 60 minutes to provide a photosensitive layer 13A (thickness 300 nm (including the thickness 250 nm of the porous layer 12)) made of a FAPbI ₃ perovskite compound.

Example 2-4
[Production of Photoelectric Conversion Element (Sample Nos. 204 and c204)]
Sample No. 1 in Example 1 In the production of the photoelectric conversion element 10A of No. 114, the photosensitive layer 13A was formed by the following method using the following light absorbent solution E instead of the light absorbent solution A, and sample No. For sample c204, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion element 10A of 204 and c204 was manufactured, respectively.
<Preparation of light absorber solution E>
CH ₃ NH ₃ I, BuNH ₃ I (n-butylammonium iodide), PbI ₂ and SnI ₂ in a molar ratio of 0.95: 0.05: 0.9: 0.1 in DMF at 60 ° C. After stirring for a period of time, the mixture was filtered with a polytetrafluoroethylene (PTFE) syringe filter to prepare a 40% by mass light absorber solution E.
BuNH ₃ I was synthesized in the same manner as purified CH ₃ NH ₃ I.
<Formation of photosensitive layer 13A>
The prepared light absorber solution E is applied on the porous layer 12 formed on the conductive support 11 by a spin coating method (2000 rpm for 60 seconds) (application temperature: 60 ° C.), and then applied light absorption. The agent solution E was dried on a hot plate at 100 ° C. for 60 minutes to obtain a photosensitive layer 13A comprising a perovskite compound of (CH ₃ NH ₃ ) _0.95 (BuNH ₃ ) _0.05 Pb _0.9 Sn _0.1 I ₃ (Thickness of 300 nm (including the thickness of the porous layer 12 of 250 nm)) was provided.

[Evaluation of photoelectric conversion element]
About each manufactured photoelectric conversion element, it carried out similarly to Example 1, and measured and evaluated the fill factor (FF).
Sample No. The photoelectric conversion element 201 has a sample No. The relative value with respect to the fill factor (FF _c201 ) of the photoelectric conversion element of _c201 was calculated and evaluated. Sample No. The photoelectric conversion element 202 has the sample No. The relative value with respect to the fill factor (FF _c202 ) of the photoelectric conversion element of _c202 was calculated and evaluated. Sample No. The photoelectric conversion element 203 has a sample No. A relative value with respect to the fill factor (FF _c203 ) of the photoelectric conversion element of _c203 was calculated and evaluated. Sample No. The photoelectric conversion element of 204 is a sample No. The relative value with respect to the fill factor (FF _c204 ) of the photoelectric conversion element of _c204 was calculated and evaluated. The results are shown in the “FF” column of Table 2.

  From the results shown in Table 2, when a photoelectric conversion element using a perovskite compound as a light absorber has a polycyclic compound-containing layer defined in the present invention, a high fill factor is exhibited regardless of the type of the perovskite compound. I understand.

Example 3
In Example 3 (3-1 to 3-4), the photoelectric conversion element which has the positive hole transport layer which changed the positive hole transport material was manufactured, and the characteristic was evaluated.

Example 3-1
[Production of Photoelectric Conversion Elements (Sample Nos. 301A, 301B, and c301)]
Sample No. 1 in Example 1 101, the film thickness of the polycyclic compound, the hole transport solution H1 and the hole transport layer is shown in Table 3. The polycyclic compound shown in Table 3, the hole transport solution H2 and the film shown in Table 3 Sample No. was changed except that the thickness was changed. In the same manner as in the manufacture of the photoelectric conversion element 10A of 101, the sample No. The photoelectric conversion elements 10A of 301A, 301B, and c301 were manufactured.
<Preparation of hole transport material solution H2>
Spiro-MeOTAD (180 mg) as a hole transport material was dissolved in chlorobenzene (1 mL). To this chlorobenzene solution, an acetonitrile solution (37.5 μL) obtained by dissolving lithium-bis (trifluoromethanesulfonyl) imide (170 mg) in acetonitrile (1 mL) and t-butylpyridine (TBP, 17.5 μL) were added. By mixing, a hole transport layer solution H2 was prepared. This hole transport material spiro-MeOTAD is a hole transport material represented by the above formula (H-1), and a commercially available product (manufactured by Merck) was used.

Example 3-2
[Production of Photoelectric Conversion Elements (Sample Nos. 302 and c302)]
Sample No. 1 in Example 1 114, the hole transport solution H1 was changed to the following hole transport solution H3. For sample c302, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion element 10A of 302 and c302 was manufactured, respectively.
<Preparation of hole transport material solution H3>
As a hole transport material, S2 (20 mg) shown below was dissolved in chloroform (1 mL) to prepare a hole transport layer solution H3. This hole transport material S2 is a hole transport material represented by the above formula (H-8), and a commercially available product (manufactured by SIGMA-ALDRICH) was used.

Example 3-3
[Production of Photoelectric Conversion Elements (Sample Nos. 303 and c303)]
Sample No. 1 in Example 1 114, the hole transport solution H1 is changed to the following hole transport solution H4. For sample c303, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion elements 10A of 303 and c303 were manufactured.
<Preparation of hole transport material solution H4>
As a hole transport material, S3 (20 mg) shown below was dissolved in chlorobenzene (1 mL) to prepare a hole transport layer solution H4. This hole transport material S3 is a hole transport material represented by the above formula (H-5). Sci. , 2017, 8, 734-741.

Example 3-4
[Production of Photoelectric Conversion Elements (Sample Nos. 304 and c304)]
Sample No. 1 in Example 1 114, the hole transport solution H1 is changed to the following hole transport solution H5. For sample c304, sample no. In the same manner as in the manufacture of the photoelectric conversion element 10A of No. 114, the sample No. The photoelectric conversion elements 10A of 304 and c304 were manufactured.
<Preparation of hole transport material solution H5>
S4 (20 mg) shown below as a hole transport material was dissolved in chloroform (1 mL) to prepare a hole transport layer solution H5. This hole transport material S3 is a hole transport material represented by the above formula (H-11). Am. Chem. Soc. , 2013, 135, 19087-19090.

[Evaluation of photoelectric conversion element]
About each manufactured photoelectric conversion element, it carried out similarly to Example 1, and measured and evaluated the fill factor (FF).
Sample No. The photoelectric conversion elements 301A and 301B have sample Nos. The relative value with respect to the fill factor (FF _c301 ) of the photoelectric conversion element of _c301 was calculated and evaluated. Sample No. The photoelectric conversion element of 302 is sample No. The relative value with respect to the fill factor (FF _c302 ) of the photoelectric conversion element of _c302 was calculated and evaluated. Sample No. The photoelectric conversion element of No. 303 is sample No. The relative value with respect to the fill factor (FF _c303 ) of the photoelectric conversion element of _c303 was calculated and evaluated. Sample No. The photoelectric conversion element of 304 is sample No. The relative value with respect to the fill factor (FF _c304 ) of the photoelectric conversion element of _c304 was calculated and evaluated. The results are shown in the “FF” column of Table 3.

  From the results in Table 3, when a photoelectric conversion element using a perovskite compound as a light absorber has a polycyclic compound-containing layer defined in the present invention, a high fill factor can be obtained even if the type of the hole transport material is changed. It can be seen that

Example 4
The photoelectric conversion element 10E shown in FIG. 5 having the layer structure of the second aspect was manufactured by the procedure shown below, and its characteristics were evaluated.
[Production of Photoelectric Conversion Element (Sample No. 401)]
<Preparation of composition for photoelectric conversion element>
The polycyclic compound a8 (4.8 mg, 5 mol) was dissolved in chlorobenzene (2 mL), and the insoluble matter was filtered with a polytetrafluoroethylene (PTFE) syringe filter to prepare a photoelectric conversion element composition A2.
<Formation of polycyclic compound-containing layer 5C>
On the ITO substrate (the conductive substrate 11, the film thickness of the transparent electrode 11b is 300 nm), the composition A2 for photoelectric conversion elements was applied by spin coating (at 1000 rpm for 30 seconds). Next, the coated composition A2 for photoelectric conversion elements was dried at 100 ° C. for 30 minutes using a hot plate. Thus, a polycyclic compound-containing layer 5C (the film thickness is shown in Table 4) was formed.

<Preparation of hole transport material solution H6>
The above S1 (10 mg) as a hole transport material was dissolved in chloroform (1 mL) to prepare a hole transport layer solution H6.
<Formation of hole transport layer 16>
Next, the prepared hole transport layer solution H6 is applied onto the polycyclic compound-containing layer 5C formed on the conductive substrate 11 by a spin coating method and dried (at 100 ° C. for 10 minutes) to obtain a solid positive electrode. A hole transport layer 16 (film thickness is shown in Table 4) was formed.

<Preparation of light absorber solution F>
The purified CH ₃ NH ₃ I and PbI ₂ obtained in Example 1 were mixed at a molar ratio of 1: 1 in DMSO at 60 ° C. for 12 hours, and then filtered through a polytetrafluoroethylene (PTFE) syringe filter. A 40 wt% light absorber solution F was prepared.
<Formation of photosensitive layer 13C>
The prepared light absorber solution F was applied onto the hole transport layer 16 by spin coating (at 2000 rpm for 60 seconds) (application temperature: 20 ° C.), and then the applied light absorber solution F was applied to a hot plate at 100 ° C. And a photosensitive layer (thickness 200 nm) 13C made of a perovskite compound of CH ₃ NH ₃ PbI ₃ was provided.
Thus, the first electrode 1E was produced.

<Preparation of Electron Transport Material Solution E1>
[6,6] -phenyl-C61-butyric acid methyl ester (PC ₆₁ BM, 20 mg / mL) was dissolved in chlorobenzene (1 mL) to prepare an electron transport material solution E1.
<Formation of electron transport layer 4>
Next, the prepared electron transport layer solution E1 was applied onto the photosensitive layer 13C by a spin coat method and dried (at 120 ° C. for 30 minutes) to form a solid electron transport layer 4 (film thickness 100 nm). .

<Preparation of the second electrode 2>
Aluminum was vapor-deposited on the electron transport layer 4 by a vapor deposition method to produce a second electrode 2 (film thickness 100 nm).
Thus, a photoelectric conversion element 10E (Sample No. 401) was manufactured.

[Production of Photoelectric Conversion Element (Sample No. c401)]
Sample No. mentioned above. In the production of the photoelectric conversion element 10E of No. 401, sample no. In the same manner as the manufacture of the photoelectric conversion element 10E of No. 401, the sample No. The photoelectric conversion element 10E of c401 was manufactured.

[Evaluation of photoelectric conversion element]
About each manufactured photoelectric conversion element, it carried out similarly to Example 1, and measured and evaluated the fill factor (FF). The evaluation is based on Sample No. The calculation was performed by calculating a relative value with respect to the fill factor (FF _c401 ) of the photoelectric conversion element of _c401 . The results are shown in the “FF” column of Table 4.

  From the result of Table 4, when the photoelectric conversion element using a perovskite compound as a light absorber is provided with the polycyclic compound-containing layer specified in the present invention, the layer structure is a hole transport layer, a polycyclic compound-containing layer. In addition, even in the layer structure of the second aspect in which the photosensitive layers are provided in this order, it can be seen that a high fill factor is exhibited as in the photoelectric conversion elements of Examples 1 to 3 having the layer structure of the first aspect.

  As described above, the photoelectric conversion element and solar cell provided with the polycyclic compound-containing layer defined in the present invention exhibit a high fill factor while containing a perovskite compound in the photosensitive layer. Moreover, the manufacturing method of the photoelectric conversion element of this invention and the composition for photoelectric conversion elements can manufacture suitably the photoelectric conversion element and solar cell of this invention which have the above-mentioned outstanding characteristic.

DESCRIPTION OF SYMBOLS 1A-1E 1st electrode 11 Conductive support body 11a Support body 11b Transparent electrode 12 Porous layer 13A-13C Photosensitive layer 14 Blocking layer 2 2nd electrode 3A, 3B, 16 Hole transport layer 4, 15 Electron transport layer 5A- 5C Polycyclic compound-containing layer 6 External circuit (lead)
10A to 10E Photoelectric conversion elements 100A to 100E System M using solar cell Electric motor

Claims (12)

Between the conductive support forming the first electrode and the second electrode facing the first electrode, the polycyclic compound-containing layer on the conductive support side, and the second electrode of the polycyclic compound-containing layer A photoelectric conversion element having a hole transport layer adjacent to the side and a photosensitive layer adjacent to the polycyclic compound-containing layer or the hole transport layer,
From the following group G, wherein the polycyclic compound-containing layer is bonded to the polycyclic structure including a partial structure represented by any of the following formulas (BS-1) to (BS-9): A photoelectric conversion element comprising a polycyclic compound having at least two groups or salts selected.

In the formula, Y ^B represents CR ¹ or a nitrogen atom. X ^B represents CR ² R ³ , SiR ⁴ R ⁵ , NR ^N , sulfur atom, selenium atom or oxygen atom. R ¹ to R ⁵ and ^{R N} represents a hydrogen atom or a substituent. M ^B represents a metal atom or a metal oxide. However, when the ring derived from pyrrole in the formulas (BS-8) and (BS-9) has a substituent, the substituents are not bonded to each other to form a ring.
[The group ^{G] -OR a, -O - Ya} +, -SR a, -S - Ya +, -NR a R b, - (NR a R b R c) + Ya -, -COOR a, -COO - _{^{Ya +, -SO 3 R a,}} -OSO 3 R a, -SO 3 - Ya +, -OSO 3 - Ya +, -P (= O) (OR a) 2, -OP (= O) (OR a _{^{) 2, -P (= O)}} (O - Ya +) 2, -OP (= O) (O - Ya +) 2, -B (oR a) 2 and _{^{-B (oR a) 3 - Ya}} +
Here, R ^a , R ^b and R ^c represent a hydrogen atom or a substituent, and Ya represents a counter salt.   The said 1st electrode has the said photosensitive layer on the said electroconductive support body, The said polycyclic compound containing layer and the said positive hole transport layer are provided in this order on the surface of the said photosensitive layer. Photoelectric conversion element.   The photoelectric conversion element according to claim 1, wherein the first electrode has the polycyclic compound-containing layer, the hole transport layer, and the photosensitive layer in this order on the conductive support. The group or salt selected from the group G forms a partial structure represented by any of the following formulas (PG-1) to (PG-3) and is bonded to the polycyclic structure. The photoelectric conversion element of any one of 1-3.

In formula, Ga-Gc shows the said group or salt said. R ^{6 to} R ¹⁰ represent a hydrogen atom or a substituent. na is an integer of 1 or more. Ring Z represents a hydrocarbon ring or a heterocyclic ring. * Indicates a binding site with the polycyclic structure. The photoelectric conversion element according to claim 1, wherein at least one of the group or the salt is the —NR ^a R ^b or the —P (═O) (OR ^a ) ₂ .   The photoelectric conversion element according to any one of claims 1 to 5, wherein the polycyclic structure and the ring structure of the hole transport material in the hole transport layer are common.   The photoelectric conversion element according to claim 1, wherein the polycyclic compound-containing layer has a thickness of 1 to 10 nm.   The photoelectric conversion element according to claim 1, wherein the hole transport layer has a thickness of 10 to 50 nm.   The photosensitive layer has a perovskite crystal structure containing a cation of a group 1 element of the periodic table or a cationic organic group, a cation of a metal atom other than the group 1 element of the periodic table, and an anion of an anionic atom or an atomic group The photoelectric conversion element of any one of Claims 1-8 containing a compound.   The solar cell using the photoelectric conversion element of any one of Claims 1-9. A method for producing the photoelectric conversion element according to any one of claims 1 to 10,
The manufacturing method of the photoelectric conversion element which has the process of providing a polycyclic compound content layer on an electroconductive support body, and the process of providing a hole transport layer in the surface of the said polycyclic compound content layer. A polycyclic compound in which at least two groups selected from the following group G3 are bonded to a polycyclic structure containing a partial structure represented by any of the following formulas (BS-1) to (BS-9); The composition for photoelectric conversion elements containing a protic solvent.

In the formula, Y ^B represents CR ¹ or a nitrogen atom. X ^B represents CR ² R ³ , SiR ⁴ R ⁵ , NR ^N , sulfur atom, selenium atom or oxygen atom. R ¹ to R ⁵ and ^{R N} represents a hydrogen atom or a substituent. M ^B represents a metal atom or a metal oxide. However, when the ring derived from pyrrole in the formulas (BS-8) and (BS-9) has a substituent, the substituents are not bonded to each other to form a ring.
[Group G3] —NR ^a R ^b and —P (═O) (OR ^a ) ₂
Here, R ^a and R ^b represent a hydrogen atom or a substituent.

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