CN113321942B

CN113321942B - Sensitizing dye, sensitizing dye composition for photoelectric conversion, photoelectric conversion element, and dye sensitized solar cell

Info

Publication number: CN113321942B
Application number: CN202110218770.3A
Authority: CN
Inventors: 冈地诚; 桦泽直朗; 佐藤洋
Original assignee: Hodogaya Chemical Co Ltd
Current assignee: Hodogaya Chemical Co Ltd
Priority date: 2020-02-28
Filing date: 2021-02-26
Publication date: 2024-06-14
Anticipated expiration: 2041-02-26
Also published as: TW202140468A; JP2021138935A; KR20210110229A; CN113321942A

Abstract

Disclosed are a sensitizing dye, a sensitizing dye composition for photoelectric conversion, a photoelectric conversion element, and a dye sensitized solar cell. Provided are a sensitizing dye having a novel structure capable of expanding a sensitization band, and further provided are a photoelectric conversion element and a dye sensitized solar cell which are excellent in photoelectric conversion characteristics, wherein the sensitizing dye is used as a sensitizing dye composition for photoelectric conversion capable of effectively obtaining a current. The sensitizing dye is represented by the following general formula (1). [ chemical 1]

Description

Sensitizing dye, sensitizing dye composition for photoelectric conversion, photoelectric conversion element, and dye sensitized solar cell

Technical Field

The invention relates to a sensitizing dye, a sensitizing dye composition for photoelectric conversion, a photoelectric conversion element, and a dye sensitized solar cell.

Background

In recent years, carbon dioxide generated from fossil fuels such as coal, oil, and natural gas is a greenhouse gas to cause global warming, and the global warming causes environmental destruction, and the world energy consumption increases due to an increase in population, so that there is a concern that the global environmental destruction is gradually developed. In this case, the use of renewable energy sources, which are different from fossil fuels and have little risk of exhaustion, is being actively studied. As a power generation system based on next-generation main renewable energy sources capable of contributing to prevention of global warming instead of thermal power generation and atomic power generation that consume fossil fuel, the use of solar energy, mainly solar photovoltaic power generation, has been increasingly important. The use of solar energy has been advanced from the generation and charging of watches and portable small-sized electronic devices, to the development and application of small-scale power generation facilities in houses and buildings, and fallow lands, which can save the cost of illumination and heating.

As a solar photovoltaic power generation means, a photovoltaic device that converts solar energy into electric energy is used for a solar cell, and as a solar cell, for example, an inorganic solar cell such as a compound semiconductor such as single crystal, polycrystalline, amorphous silicon, gallium arsenide, cadmium sulfide, indium copper selenide, etc. is mainly studied, and is currently widely put into practical use in houses and small-scale power generation facilities. However, such an inorganic solar cell has problems such as high manufacturing cost and difficulty in securing raw materials.

On the other hand, although the photoelectric conversion rate and durability are significantly lower than those of inorganic solar cells, organic solar cells such as organic thin film solar cells and dye sensitized solar cells using various organic materials have been developed. Organic solar cells are considered to be advantageous over inorganic solar cells in terms of manufacturing cost, large area, light weight, thin film, light transmittance, wide absorption wavelength range, flexibility, securing of raw materials, and the like.

Among them, dye-sensitized solar cells proposed by Gretzel and the like (see non-patent document 1) are thin film electrodes made of porous titanium oxide as a semiconductor, ruthenium complex dye adsorbed on the surface of the semiconductor for expanding the photosensitive band, and wet solar cells made of an electrolyte containing iodine, and high photoelectric conversion efficiency matching with amorphous silicon solar cells is expected. Dye-sensitized solar cells have been attracting attention as next-generation solar cells because they have a simple element structure and can be manufactured without large-scale manufacturing facilities, as compared with other solar cells.

Ruthenium complexes are considered to be optimal as sensitizing dyes for dye sensitized solar cells from the viewpoint of photoelectric conversion efficiency, but ruthenium is a noble metal, and therefore is disadvantageous in terms of manufacturing cost, and when a large amount of ruthenium complexes is required for practical use, resource constraints are also problematic. Therefore, studies on dye-sensitized solar cells using organic dyes that do not contain noble metals such as ruthenium have been actively conducted as the sensitizing dye. As organic dyes containing no noble metal, coumarin dyes, cyanine dyes, merocyanine dyes, rhodamine dyes, phthalocyanine dyes, porphyrin dyes, x-ton dyes, and the like are disclosed (for example, refer to patent documents 1 to 3). The present inventors have also proposed a compound having a 9, 10-dihydroacridine (acridan) skeleton, a phenothiazine (phenothiazine) skeleton, or the like as an organic dye having an excellent sensitizing effect (refer to patent document 4).

Further, as an electron-withdrawing portion for adsorbing on the surface of semiconductor particles such as titanium oxide and efficiently transporting excitation electrons generated in a sensitizing dye to a semiconductor, a compound having an indenone structure has been proposed (for example, refer to patent documents 6 to 7).

However, these organic dyes have the advantages of low cost, large absorption coefficient, and capability of controlling absorption characteristics by various structures, but they have not been able to sufficiently satisfy desired characteristics in terms of photoelectric conversion efficiency and stability with time.

Patent literature

Patent document 1: japanese patent laid-open No. 11-214730

Patent document 2: japanese patent laid-open No. 11-238905

Patent document 3: japanese patent laid-open publication No. 2011-26376

Patent document 4: japanese patent laid-open No. 2013-60581

Patent document 5: japanese patent laid-open publication No. 2011-207784

Patent document 6: japanese patent application laid-open No. 2012-51854

Patent document 7: japanese patent laid-open publication 2016-6811

Non-patent literature

Non-patent document 1: "Nature", UK, 1991, volume 353, pages 737-740

Disclosure of Invention

The present invention provides a sensitizing dye having a novel structure capable of expanding a sensitization band, and further provides a photoelectric conversion element and a dye sensitized solar cell having excellent photoelectric conversion characteristics, wherein the sensitizing dye is used as a sensitizing dye composition for photoelectric conversion capable of effectively obtaining a current.

As a result of intensive studies for improving the photoelectric conversion characteristics of a sensitizing dye, the inventors have found that a high-efficiency and high-durability photoelectric conversion element can be obtained by using a sensitizing dye having a specific structure as a sensitizing dye for photoelectric conversion. Namely, the present invention is constituted as follows.

A sensitizing dye represented by the following general formula (1),

[ Chemical 1]

Wherein R ⁰ represents a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent or an aryl group having 6 to 36 carbon atoms which may have a substituent,

R ¹～R⁴ are identical or different and represent a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a nitro group, a nitroso group, a thiol group,

A linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent,

Cycloalkyl group having 3 to 36 carbon atoms which may have a substituent,

A linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent,

A C3-36 cycloalkoxy group which may have a substituent,

A linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent,

Aryl group having 6 to 36 carbon atoms which may have a substituent,

Or an amino group having 0 to 36 carbon atoms which may have a substituent,

R ¹～R⁴ can bond to each other between adjacent groups to form a ring,

X represents a sulfur atom, an oxygen atom or CR ⁵R⁶,R⁵、R⁶ which are the same or different and each represents a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent or an aryl group having 6 to 36 carbon atoms which may have a substituent,

Y represents a sulfur atom, an oxygen atom, CR ⁷R⁸ or NR ⁹,R⁷～R⁹, which are the same or different, and represents a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent, or an aryl group having 6 to 36 carbon atoms which may have a substituent,

A represents a monovalent radical and B represents a divalent radical or a single bond.

A dye composition for photosensitizing photoelectric conversion comprising the dye represented by the general formula (1).

A photoelectric conversion element using the dye composition for sensitization.

A dye-sensitized solar cell using the photoelectric conversion element.

According to the sensitizing dye of the present invention, a sensitizing dye composition for photoelectric conversion that can efficiently obtain a current can be obtained. Further, by using the dye composition for photoelectric conversion, a photoelectric conversion element and a dye-sensitized solar cell having high efficiency and high durability can be obtained.

Drawings

Fig. 1 is a schematic cross-sectional view showing the structure of a photoelectric conversion element according to an embodiment of the present invention and a comparative example.

(Description of the reference numerals)

1A conductive support; 2a dye-bearing semiconductor layer; 3 an electrolyte layer; 4. a counter electrode; 5 conductive support.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. First, this embodiment will be described with reference to examples.

1. A sensitizing dye represented by the following general formula (1),

[ Chemical 1]

Cycloalkyl group having 3 to 36 carbon atoms which may have a substituent,

A C3-36 cycloalkoxy group which may have a substituent,

Aryl group having 6 to 36 carbon atoms which may have a substituent,

Or an amino group having 0 to 36 carbon atoms which may have a substituent,

R ¹～R⁴ can bond to each other between adjacent groups to form a ring,

2. A sensitizing dye, wherein,

In the above general formula (1), A is a 1-valent group represented by any one of the following general formulae (2) to (4),

[ Chemical 2]

Wherein R ²⁰ and R ²¹ represent a hydrogen atom or an acidic group, and at least one of R ²⁰ and R ²¹ is an acidic group, R ²² and R ²⁴ represent an acidic group, and R ²³ and R ²⁵ represent a hydrogen atom or an electron withdrawing group.

3. A sensitizing dye, wherein,

In the general formula (1), B is a bond or a single bond of 2-valence represented by the following general formula (5),

[ Chemical 3]

Wherein Z represents a carbon atom or a silicon atom,

R ³⁰ and R ³¹ are the same or different and each represents a hydrogen atom,

Or an aryl group having 6 to 36 carbon atoms which may have a substituent,

R ³² to R ³⁷ are the same or different and represent a hydrogen atom,

Or a linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent,

R ³² and R ³³,R³⁴ and R ³⁵ and R ³⁶ and R ³⁷ are each the same or different and are each bonded to each other to form a ring,

P, q and r represent 0 or 1.

4. A sensitizing dye, wherein,

In the general formula (1), R ⁰ is a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 26 carbon atoms which may have a substituent, and R ¹～R⁴ is a hydrogen atom,

Aryl group having 6 to 36 carbon atoms which may have a substituent,

Or an amino group having 0 to 36 carbon atoms which may have a substituent,

X is CR ⁵R⁶ or a sulfur atom,

Y is a sulfur atom, CR ⁷R⁸ or NR ⁹.

5. A dye composition for photoelectric conversion comprising the dye.

6. A photoelectric conversion element using the dye composition for sensitization.

7. A dye-sensitized solar cell using the photoelectric conversion element.

The dye composition for photoelectric conversion comprising the dye for sensitization of the present application is used as a sensitizer in a dye-sensitized photoelectric conversion element. In the present specification, "sensitizing dye" means a compound represented by the general formula (1), and "sensitizing dye composition for photoelectric conversion" means a composition containing one or two or more compounds represented by the general formula (1) and optionally containing other sensitizing dyes not belonging to the present application. The "photoelectric conversion element" of the present application is typically a structure in which a photoelectrode formed by adsorbing a dye to a semiconductor layer on a conductive support and a counter electrode are disposed so as to face each other with an electrolyte layer interposed therebetween.

The sensitizing dye represented by the general formula (1) is specifically described below, but the present invention is not limited thereto.

In the general formula (1), as the "linear or branched alkyl group having 1 to 36 carbon atoms" in the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰, specifically, examples thereof include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and the like; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl and isooctyl.

In the general formula (1), as the "aryl group having 6 to 36 carbon atoms" in the "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁰, specifically, an aryl group such as a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthroline group, a pyrenyl group, a triethylene group, an indenyl group, a fluorenyl group, or the like may be mentioned. Here, "aryl" in the present invention means an aromatic hydroxy group and a condensed polycyclic aryl group, and among them, phenyl, naphthyl and biphenyl are preferable.

In the general formula (1), as "substituent" in "linear or branched alkyl group having 1 to 36 carbon atoms which may have substituent" and "aryl group having 6 to 36 carbon atoms which have substituent" represented by R ⁰,

Specifically, there may be mentioned: halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom;

Cyano group; a hydroxyl group; a nitro group; a nitroso group; a thiol group;

cycloalkyl groups having 3 to 34 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl;

straight-chain alkoxy groups having 1 to 34 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like;

Branched alkoxy groups having 3 to 34 carbon atoms such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy and isooctoxy;

A cycloalkoxy group having 3 to 34 carbon atoms such as a cyclopropyloxy group, a cyclobutoxy group, a cyclopentyloxy group, a cyclohexyloxy group and the like;

Aryl groups having 6 to 34 carbon atoms such as phenyl, naphthyl, biphenyl, anthryl, phenanthryl, pyrenyl, triphenylene, indenyl, fluorenyl and the like;

unsubstituted amino; amino groups having a substituent having 1 to 34 carbon atoms such as methylamino, dimethylamino, diethylamino, ethylmethylamino, methylpropylamino, di-t-butylamino, and diphenylamino;

a carboxyl group; carboxylic acid ester groups such as methyl, ethyl, etc. These "substituents" may be contained in one or more than one, and when contained in a plurality, they may be the same as or different from each other. In addition, these "substituents" may further have the substituents exemplified above.

In the above general formula (1), R ⁰ is preferably a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 26 carbon atoms which may have a substituent, more preferably an aryl group having 6 to 16 carbon atoms which may have a substituent, and most preferably an aryl group having 6 to 12 carbon atoms. The "substituent" at R ⁰ is preferably a linear alkoxy group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms which may have a substituent, or an aryl group having 6 to 30 carbon atoms which may have a substituent, more preferably a linear alkoxy group having 1 to 10 carbon atoms, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, or an aryl group having 6 to 16 carbon atoms which may have a substituent, and most preferably a linear alkoxy group having 1 to 10 carbon atoms, a linear or branched alkenyl group having 2 to 6 carbon atoms which may be substituted with an allyl group having 6 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

In the general formula (1), the "halogen atom" represented by R ¹～R⁴ specifically includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

In the general formula (1), the "alkyl group having 1 to 36 carbon atoms" in the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ is the same as the "alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1).

In the general formula (1), as "cycloalkyl group having 3 to 36 carbon atoms" in "cycloalkyl group having 3 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴, specifically, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl and the like are mentioned.

In the general formula (1), as the "linear or branched alkoxy group having 1 to 36 carbon atoms" in the "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴, specifically, examples thereof include linear alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, hexoxy group, heptoxy group, octoxy group, nonoxy group, decyloxy group and the like; branched alkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy and isooctoxy.

In the general formula (1), the "cycloalkoxy group having 3 to 36 carbon atoms" in the "cycloalkoxy group having 3 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ is specifically exemplified by cyclopropyloxy, cyclobutoxy, cyclopentyloxy, cyclohexyloxy and the like.

In the general formula (1), as the "linear or branched alkenyl group having 2 to 36 carbon atoms" in the "linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴, specifically, there may be mentioned alkenyl groups such as vinyl, propenyl, isopropenyl, 2-butenyl, 1-hexenyl, or the like, or linear or branched alkenyl groups to which a plurality of these alkenyl groups are bonded.

In the general formula (1), "aryl group having 6 to 36 carbon atoms" as "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ may be the same as "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1).

In the general formula (1), "an amino group having 0 to 36 carbon atoms" in the "amino group having 0 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴, specifically, includes: unsubstituted amino; methylamino, dimethylamino, diethylamino, ethylmethylamino, methylpropylamino, di-t-butylamino, diphenylamino, and the like.

In the general formula (1), the "substituent" in the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent", "cycloalkyl group having 3 to 36 carbon atoms which may have a substituent", "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent", "cycloalkoxy group having 3 to 36 carbon atoms which may have a substituent", "linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent", "aryl group having 6 to 36 carbon atoms which may have a substituent" or "amino group having 0 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1) is the same as the "substituent" in the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" and "aryl group having 6 to 36 carbon atoms which may have a substituent".

In the general formula (1), R ¹～R⁴ may be the same or different, and is preferably a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms which may have a substituent, an aryl group having 6 to 24 carbon atoms which may have a substituent, or an amino group having 0 to 24 carbon atoms which may have a substituent, and more preferably an aryl group having 6 to 24 carbon atoms which may have a hydrogen atom or a substituent.

In the general formula (1), R ¹～R⁴ represents a substituent as described above, but may be bonded to each other between adjacent groups to form a ring, and these rings may be bonded to each other by any one atom of a single bond, a nitrogen atom, an oxygen atom, or a sulfur atom to form a ring.

In the above general formula (1), R ¹～R⁴ is preferably a hydrogen atom, a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent, an aryl group having 6 to 36 carbon atoms which may have a substituent, or an amino group having 0 to 36 carbon atoms which may have a substituent, more preferably a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, or an amino group having 0 to 20 carbon atoms which may have a substituent. In R ¹～R⁴, R ¹、R² and R ⁴ may be a hydrogen atom, and R ³ may be a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, or an amino group having 0 to 20 carbon atoms which may have a substituent. In R ¹～R⁴, R ¹、R² and R ⁴ may be a hydrogen atom, and R ³ may be an aryl group having 6 to 20 carbon atoms.

In the general formula (1), X represents CR ⁵R⁶, a sulfur atom or an oxygen atom, in CR ⁵R⁶, "an alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁵ and R ⁶ may be the same as "an alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1), "an straight-chain or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁵ and R ⁶ may be the same as "an straight-chain or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ in the general formula (1), and "an aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁵ and R ⁶ may be the same as "an aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1), and R ⁶ may be the same as or different from each other. X in the present invention is preferably CR ⁵R⁶ or a sulfur atom, more preferably CR ⁵R⁶.

In the general formula (1), when X is CR ⁵R⁶, R ⁵ and R ⁶ are preferably a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, or an aryl group having 6 to 36 carbon atoms which may have a substituent, more preferably an aryl group having 6 to 36 carbon atoms which may have a substituent, and most preferably an aryl group having 6 to 20 carbon atoms. When aryl is a benzene ring, a part of the description of the present application is denoted as Ph.

In the general formula (1), Y represents a sulfur atom, an oxygen atom, CR ⁷R⁸ or NR ⁹, in CR ⁷R⁸ or NR ⁹, the "alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁷～R⁹ is the same as the "alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1), the "straight-chain or branched-chain alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁷～R⁹ is the same as the "straight-chain or branched-chain alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ in the general formula (1), and the "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁷～R⁹ is the same as the "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1), and R ⁷～R⁹ may be the same or different. Y in the present invention is preferably a sulfur atom, CR ⁷R⁸ or NR ⁹, more preferably a sulfur atom or CR ⁷R⁸.

In the general formula (1), when Y is CR ⁷R⁸, R ⁷ and R ⁸ are preferably a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, or an aryl group having 6 to 36 carbon atoms which may have a substituent, more preferably a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, and most preferably a linear or branched alkyl group having 1 to 16 carbon atoms.

In the general formula (1), when Y is NR ⁹, R ⁹ is more preferably a linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent, or an aryl group having 6 to 36 carbon atoms which may have a substituent, and most preferably a linear or branched alkyl group having 1 to 16 carbon atoms.

In the general formula (1), a is preferably represented by any one of 1-valent groups in the general formulae (2) to (4).

In the general formula (2), R ²⁰ and R ²¹ represent a hydrogen atom or an acidic group, and at least one of R ²⁰ or R ²¹ is an acidic group. Specific examples of the "acidic group" include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a hydroxamic acid group, a phosphonic acid group, a boric acid group, a phosphinic acid group, a silanol group, and the like. Among them, carboxyl or phosphonic acid groups are preferable, and carboxyl groups are more preferable. Since the sensitizing dye containing a carboxyl group or a phosphonic acid group as an acidic group can be easily adsorbed on the surface of the semiconductor layer, the photoelectric conversion characteristics of the photoelectric conversion element using the sensitizing dye will be further improved.

The "acidic group" represented by R ²² in the general formula (3) and the "acidic group" represented by R ²⁴ in the general formula (4) are the same as the "acidic group" in the general formula (2).

In the general formula (4), R ²³ and R ²⁵ represent a hydrogen atom or an electron-attracting group, and as a specific example, "electron-attracting group" may be mentioned as:

halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom;

cyano group; a hydroxyl group; a nitro group; a nitroso group; a carboxyl group; a formyl group; ester groups, trifluoromethyl groups, and the like. Among them, cyano, nitro, trifluoromethyl, carboxyl, and the like are preferable.

In the general formula (1), specifically, B is preferably a 2-valent group or a single bond represented by the general formula (5).

In the general formula (5), the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ³⁰ and R ³¹ is the same as the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1).

In the general formula (5), "linear or branched alkoxy group having 1 to 36 carbon atoms" in "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ³⁰ and R ³¹ is the same as "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ in the general formula (1).

In the general formula (5), "aryl group having 6 to 36 carbon atoms" in "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ³⁰ and R ³¹ includes the same "aryl group having 6 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1).

In the general formula (5), the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ³²～R³⁷ is the same as the "linear or branched alkyl group having 1 to 36 carbon atoms which may have a substituent" represented by R ⁰ in the general formula (1).

In the general formula (5), the "linear or branched alkoxy group having 1 to 36 carbon atoms" in the "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ³²～R³⁷ is the same as the "linear or branched alkoxy group having 1 to 36 carbon atoms which may have a substituent" represented by R ¹～R⁴ in the general formula (1).

In the general formula (5), the "linear or branched alkenyl group having 2 to 36 carbon atoms" in the "linear or branched alkenyl group having 2 to 36 carbon atoms which may have a substituent" represented by R ³²～R³⁷ is the same as the "linear or branched alkenyl group having 2 to 36 carbon atoms" represented by R ¹～R⁴ in the general formula (1).

In the general formula (5), R ³² and R ³³,R³⁴ and R ³⁵, and R ³⁶ and R ³⁷ may be the same or different and represent substituents as described above, but may be bonded to each other between adjacent groups to form a ring, and the rings may be bonded to each other by single bonding or bonding through any one of a nitrogen atom, a carbon atom and a sulfur atom to form a ring.

In the general formula (5), the amino acid sequence of the compound,

P, q, r can be 0, p, q, r can be 1, 0, p, q, r can be 0, 1, 0, p, q, r can be 0, 1, p q and r may be 1, 0, p, q and r may be 1, 0, 1, p, q and r may be 0, 1, p, q and r may be 1, 1 and 1, respectively.

In the present invention, the sensitizing dye represented by the general formula (1) contains all stereoisomers which may be present. Any stereoisomer may be suitable for use as the sensitizing dye of the present invention. For example, in the general formula (1), when B is a 2-valent group or a single bond represented by the general formula (5), a is a 1-valent group represented by the general formula (2), p is 0, q is 0, R ²⁰ is a hydrogen atom, and R ²¹ is a carboxyl group, the sensitizing dye of the present invention comprises compounds represented by the following general formulae (6) and (7). In addition, it may be a mixture of 2 or more kinds selected from these stereoisomers.

[ Chemical 4]

Specific examples of the compound of the sensitizing dye of the present invention represented by the general formula (1) are represented by the following formula, but the present invention is not limited thereto.

In addition, the following example compounds illustrate one example of stereoisomers that may exist, including all other stereoisomers. In addition, each may be a mixture of two or more stereoisomers.

[ Chemical 5]

[ Chemical 6]

[ Chemical 7]

[ Chemical 8]

[ Chemical 9]

[ Chemical 10]

[ Chemical 11]

[ Chemical 12]

[ Chemical 13]

[ Chemical 14]

[ 15]

[ 16]

[ Chemical 17]

[ Chemical 18]

[ Chemical 19]

[ Chemical 20]

[ Chemical 21]

[ Chemical 22]

[ Chemical 23]

[ Chemical 24]

[ Chemical 25]

[ Chemical 26]

[ Chemical 27]

[ Chemical 28]

[ Chemical 29]

[ Chemical 30]

[ 31]

[ Chemical 32]

[ 33]

[ Chemical 34]

[ 35]

[ 36]

[ 37]

[ 38]

[ 39]

[ 40]

[ Chemical 41]

[ Chemical 42]

[ Chemical 43]

[ 44]

[ 45]

[ Chemical 46]

[ 47]

[ 48]

The sensitizing dye of the present invention represented by the general formula (1) can be synthesized by a known method. In the following, a synthetic example is shown in the case where Y is a sulfur atom, B is a 2-valent group or single bond represented by the general formula (5), A is a 1-valent group represented by the general formula (2), p is 0, q is 1, R is 0, R ³²、R³³、R³⁴, and R ³⁵ are hydrogen atoms in the general formula (1).

The bromine compound represented by the general formula (9) can be synthesized by performing a cross-coupling reaction such as a bell wood-palace coupling reaction of a borate compound having a corresponding substituent represented by the general formula (8) with 4-bromo-2, 1, 3-benzothiazole, and further performing a bromination reaction.

[ 49]

Then, the formyl compound represented by the general formula (10) can be synthesized by performing a cross-coupling reaction of the bromo compound represented by the general formula (9) with 4-formylphenylboronic acid.

[ 50]

Then, the dye of the present invention represented by the general formula (1) can be synthesized by performing a condensation reaction of the formyl compound represented by the general formula (10) obtained as described above with the indanone compound represented by the general formula (11).

In the general formula (11), R ²⁰ and R ²¹ represent a hydrogen atom or an acidic group, and at least one of R ²⁰ and R ²¹ is an acidic group.

In the above synthetic examples, R ⁰～R⁴、R²⁰ and R ²¹ in the general formulae (8) to (11) represent the same meanings as R ⁰～R⁴ in the general formula (1) and R ²⁰、R²¹ in the general formula (2) of the present invention.

The general formula (8) and the like as the starting materials may be commercially available or synthesized by a known method. The indanone compound represented by the above general formula (11) can be easily synthesized by the methods described in the above patent documents 6 to 7.

The method for purifying the compound of the sensitizing dye of the present invention represented by the general formula (1) includes: refining according to column chromatography purification; adsorption refining based on silica gel, activated carbon, activated clay, etc.; known methods such as recrystallization and crystallization based on a solvent. The identification of these compounds can be performed by nuclear magnetic resonance analysis (NMR) or the like.

The sensitizing dye of the present invention may be used alone or in combination of two or more. In addition, the sensitizing dye of the present invention may be used in combination with other sensitizing dyes not belonging to the present invention. Specific examples of the other sensitizing dye include a sensitizing dye other than the sensitizing dye represented by the general formula (1), such as ruthenium complex, coumarin dye, cyanine dye, merocyanine dye, rhodamine dye, phthalocyanine dye, porphyrin dye, and x-ton dye. When the sensitizing dye of the present invention is used as a composition for photoelectric conversion in combination with these other sensitizing dyes, the amount of the other sensitizing dye to be used for the sensitizing dye of the present invention is preferably 10 to 200% by weight, more preferably 20 to 100% by weight.

The sensitizing dye of the present invention can be used as a spectral sensitizing dye for various imaging materials, such as a photosensitive substance, a photocatalyst, and an optical functional material, for example, silver halide, zinc oxide, and titanium oxide, and can be used as a sensitizing dye composition for photoelectric conversion for a dye sensitized photoelectric conversion element, etc. The method of manufacturing the dye-sensitized photoelectric conversion element in the present invention is not particularly limited, but the following method is preferable: a semiconductor layer is formed on a conductive support (electrode), and the photosensitizing dye composition for photoelectric conversion of the present invention is adsorbed (supported) on the semiconductor layer to produce a photoelectrode (see fig. 1. Needless to say, the drawing is for ease of understanding and is therefore not a true size of an actual element). As a method for adsorbing the dye, a method in which the semiconductor layer is immersed in a solution obtained by dissolving the dye in a solvent for a long period of time is generally used. When two or more kinds of the sensitizing dye of the present invention are used in combination, or when the sensitizing dye of the present invention is used in combination with other sensitizing dye, a mixed solution of all the dyes used may be prepared to impregnate the semiconductor layer, or alternatively, different solutions may be prepared for the respective dyes, and the semiconductor layer may be sequentially impregnated in the respective solutions.

In the present invention, as the conductive support, a glass substrate or a plastic substrate provided with a conductive layer having a conductive material on the surface thereof may be used in addition to the metal plate. Specific examples of the conductive material include metals such as gold, silver, copper, aluminum, and platinum, conductive transparent oxide semiconductors such as fluorine-doped tin oxide and indium tin composite oxide, carbon, and the like, and a glass substrate coated with a fluorine-doped tin oxide thin film is preferably used.

In the present invention, specific examples of the semiconductor forming the semiconductor layer include: metal oxides such as titanium oxide, zinc oxide, tin oxide, indium oxide, zirconium oxide, tungsten oxide, tantalum oxide, iron oxide, gallium oxide, nickel oxide, and yttrium oxide; metal sulfides such as titanium sulfide, zinc sulfide, zirconium sulfide, copper sulfide, tin sulfide, indium sulfide, tungsten sulfide, cadmium sulfide, and silver sulfide; metal selenides such as titanium selenide, zirconium selenide, indium selenide, and tungsten selenide; a monolithic semiconductor such as silicon or germanium. These semiconductors may be used not only singly but also in combination of two or more. In the present invention, the semiconductor is preferably one or more selected from titanium oxide, zinc oxide, and tin oxide.

The form of the semiconductor layer in the present invention is not particularly limited, but is preferably a thin film having a porous structure composed of fine particles. By the porous structure or the like, the actual surface area of the semiconductor layer increases, and if the dye adsorption amount of the semiconductor layer increases, a photoelectric conversion element with high efficiency can be obtained. The semiconductor particle diameter is preferably 5 to 500nm, more preferably 10 to 100nm. The film thickness of the semiconductor layer is usually 1 to 100. Mu.m, more preferably 1 to 20. Mu.m. Examples of the method for producing the semiconductor layer include, but are not limited to, a method of forming a film by a spin coating method, a doctor blade film forming method, a brush coating method, a screen printing method, or the like, a method of forming a film by applying a slurry containing semiconductor fine particles on a conductive substrate by a wet coating method, and then removing a solvent or an additive by baking, a method of forming a film by a sputtering method, a vapor deposition method, an electrodeposition method, a microwave irradiation method, or the like.

In the present invention, a slurry containing semiconductor fine particles may be used in the market, or a slurry prepared by dispersing a fine semiconductor powder in a solvent may be used. Specific examples of the solvent used in the preparation of the slurry include water; alcohol solvents such as methanol, ethanol, and isopropanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; hydrocarbon solvents such as n-hexane, cyclohexane, benzene, toluene, etc., but are not limited thereto. These solvents may be used alone or as a mixture of two or more solvents.

In the present invention, the method of dispersing the semiconductor fine powder in the solvent may be carried out after grinding the powder with a mortar or the like, or a dispersing machine such as a ball mill, a paint conditioner, a vertical bead mill, a horizontal bead mill, or an attritor may be used. The slurry is preferably prepared by adding a surfactant or the like for preventing aggregation of the semiconductor fine particles, and preferably by adding a thickener such as polyethylene glycol for thickening.

The surface of the semiconductor layer of the photosensitizing dye composition for photoelectric conversion of the present invention can be, for example, immersed in the dye solution, and left at room temperature for 30 minutes to 100 hours or heated for 10 minutes to 24 hours. In this case, it is preferable to leave it at room temperature for 10 to 20 hours, and the dye concentration in the dye solution is preferably 10 to 2000. Mu.M, more preferably 50 to 500. Mu.M.

The solvent used for adsorbing the photosensitizing dye for photoelectric conversion of the present invention on the surface of the semiconductor layer is specifically: alcohol solvents such as methanol, ethanol, isopropanol, and t-butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; ester solvents such as ethyl formate, ethyl acetate, and n-butyl acetate; ether solvents such as diethyl ether, 1, 2-dimethoxyethane, tetrahydrofuran, and 1, 3-dioxolane; amide solvents such as N, N-dimethylformamide, N-dimethylacetamide, and N-methyl-2-pyrrolidone; nitrile solvents such as acetonitrile, methoxyacetonitrile, propionitrile, etc.; halogenated hydrocarbon solvents such as methylene chloride, chloroform, bromoform, o-dichlorobenzene, etc.; hydrocarbon solvents such as n-hexane, cyclohexane, benzene, toluene, etc., but are not limited thereto. These solvents are used alone or as a mixed solvent of two or more. Among these solvents, one or two or more selected from methanol, ethanol, t-butanol, acetone, methyl ethyl ketone, tetrahydrofuran, and acetonitrile are preferably used.

When the photosensitizing dye composition for photoelectric conversion of the present invention is adsorbed on the surface of the semiconductor layer, cholic acid or cholic acid derivatives such as deoxycholic acid, chenodeoxycholic acid, lithocholic acid, and dehydrocholic acid may be dissolved in a dye solution and co-adsorbed with the dye. By using cholic acid or a cholic acid derivative, polymerization between dyes is suppressed, and electrons can be efficiently injected from the dye to the semiconductor layer in the photoelectric conversion element. When cholic acid or a cholic acid derivative is used, the concentration thereof in the dye solution is preferably 0.1 to 100mM, more preferably 0.5 to 10mM.

The counter electrode (electrode) used in the photoelectric conversion element of the present invention is not particularly limited as long as it is a substance having conductivity, but a conductive material having catalytic ability is preferably used in order to promote redox reaction of redox ions. Specific examples of the conductive material include, but are not limited to, platinum, rhodium, ruthenium, carbon, and the like. In the present invention, it is particularly preferable to use a substance in which a platinum thin film is formed on a conductive support as a counter electrode. Further, as a method for producing the conductive thin film, there is mentioned: a method of forming a film by applying a slurry containing a conductive material to a conductive substrate by a wet coating method such as a spin coating method, a doctor blade film forming method, a brushing method, or a screen printing method, and then removing a solvent or an additive by baking; a method of forming a film by sputtering, vapor deposition, electrodeposition, microwave irradiation, or the like, but is not limited thereto.

In the photoelectric conversion element of the present invention, an electrolyte is filled between a pair of opposing electrodes, thereby forming an electrolyte layer. As the electrolyte used, a redox electrolyte is preferable. Examples of redox electrolytes include, but are not limited to, redox ion pairs such as iodine, bromine, tin, iron, chromium, and anthraquinone. Among these, iodine-based electrolytes and bromine-based electrolytes are preferable. In the case of an iodine-based electrolyte, for example, a mixture of potassium iodide, lithium iodide, dimethyl imidazole iodide, and the like, and iodine is used. In the present invention, an electrolyte solution obtained by dissolving these electrolytes in a solvent is preferably used. The concentration of the electrolyte in the electrolyte solution is preferably 0.05 to 5M, more preferably 0.2 to 1M.

As a solvent for dissolving the electrolyte, there may be mentioned: nitrile solvents such as acetonitrile, methoxyacetonitrile, propionitrile, 3-methoxypropionitrile, benzonitrile, etc.; ether solvents such as diethyl ether, 1, 2-dimethoxyethane, and tetrahydrofuran; amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide; carbonate solvents such as ethylene carbonate and propylene carbonate; lactone solvents such as gamma-butyrolactone and gamma-valerolactone, but are not limited thereto. These solvents are used alone or as a mixed solvent of two or more. Among these solvents, nitrile solvents are preferable.

In the present invention, in order to further increase the open circuit voltage and the fill factor of the dye-sensitized photoelectric conversion element, an amine compound may be contained in the electrolyte. Examples of the amine compound include 4-tert-butylpyridine, 4-methylpyridine, 2-vinylpyridine, N-dimethyl-4-aminopyridine, N-dimethylaniline, and N-methylbenzimidazole. The concentration of the amine compound in the electrolyte is preferably 0.05 to 5M, more preferably 0.2 to 1M.

As the electrolyte in the photoelectric conversion element of the present invention, a gel electrolyte obtained by adding a gelling agent, a polymer, or the like, or a solid electrolyte using a polymer such as a polyethylene oxide derivative may be used. By using a gel electrolyte or a solid electrolyte, volatilization of the electrolyte solution can be reduced.

In the photoelectric conversion element of the present invention, a solid charge transport layer may be formed between a pair of opposing electrodes instead of the electrolyte. The charge transport material contained in the solid charge transport layer is preferably a hole transport material. Specific examples of the charge transport material include: inorganic hole transport substances such as copper iodide, copper bromide, copper thiocyanate, and the like; organic hole transporting substances such as polypyrrole, polythiophene, polyparaphenylene vinylene, polyvinylcarbazole, polyaniline, oxadiazole derivatives, triphenylamine derivatives, pyrazoline derivatives, fluorenone derivatives, hydrazone compounds, and stilbene compounds, but are not limited thereto.

In the present invention, when the solid charge transport layer is formed using an organic hole transport substance, a film-forming binder resin may be used in combination. Specific examples of the film-forming adhesive resin include, but are not limited to, polystyrene resin, polyvinyl acetal resin, polycarbonate resin, polysulfone resin, polyester resin, polyphenylene ether resin, polyarylate resin, alkyd resin, acrylic resin, phenoxy resin, and the like. These resins may be used alone or as a copolymer in combination of one or two or more. The amount of the organic hole-transporting substance used for these binder resins is preferably 20 to 1000% by weight, more preferably 50 to 500% by weight.

In the photoelectric conversion element of the present invention, an electrode (photoelectrode) provided with a semiconductor layer to which the dye composition for photoelectric conversion is adsorbed serves as a cathode, and a counter electrode serves as an anode. The light such as sunlight may be irradiated from either one of the photoelectrode side and the counter electrode side, but is preferably irradiated from the photoelectrode side. The dye absorbs light to be in an excited state by irradiation with sunlight or the like, and releases electrons. The electrons flow to the outside through the semiconductor layer, and move to the counter electrode. On the other hand, the dye that releases electrons to be in an oxidized state receives electrons supplied from the counter electrode via ions in the electrolyte, and returns to the base state. Through this cycle, a current flows, functioning as a photoelectric conversion element.

In evaluating the performance (characteristics) of the photoelectric conversion element of the present invention, measurement of short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency was performed. The short-circuit current means a current of ² per 1cm flowing between both terminals when the output terminal is short-circuited, and the open-circuit voltage means a voltage between both terminals when the output terminal is open-circuited. In addition, the fill factor refers to a value of a maximum output (product of a circuit and a voltage) divided by a product of a short-circuit current and an open-circuit voltage, and depends mainly on internal resistance. The photoelectric conversion efficiency was obtained by multiplying 100 by the value obtained by dividing the maximum output (W) by the light intensity (W) per 1cm ², and expressing the result as a percentage.

The photoelectric conversion element of the present invention can be applied to dye-sensitized solar cells, various optical sensors, and the like. The dye-sensitized solar cell of the present invention is obtained as follows: the photoelectric conversion element containing the dye composition for photoelectric conversion containing the dye represented by the general formula (1) is formed into a unit, and the unit is arranged in a desired number and modularized, and a predetermined harness is provided.

Examples

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. In addition, in the synthesis examples, the identification of the compounds was carried out by ¹ H-NMR analysis (JNM-ECZ-400S, manufactured by Japanese electronics Co., ltd.).

Synthesis example 1 Synthesis of sensitizing dye (D-20)

To a nitrogen-substituted reaction vessel, 7.03g of (4, 4-dihexyl-4H-cyclopentane [1,2-b:5,4-b' ] dithiophene-2-yl) trimethyl stent, 4.47g of 4, 7-dibromobenzene [ c ] [1,2,5] thiadiazole and 130mL of toluene were charged, and 0.239g of bis (triphenylphosphine) palladium (type II) dichloride was added to carry out degassing under reduced pressure. The reaction was carried out at 60℃with stirring for 6 hours. After cooling to 40 ℃ and removing the solvent under reduced pressure, the crude product was purified by a column chromatography (carrier: silica gel, eluent: hexane/chloroform=1/1 (volume ratio)) to obtain 3.94g of a red oil represented by the following formula (12).

[ 51]

Into a nitrogen-substituted reaction vessel, 0.406g of the compound represented by the above formula (12), 0.54g of 10-biphenyl-9, 9-biphenyl-7- (4, 5-tetramethyl-1, 3, 2-dioxaborane-2-yl) -2-phenyl-9, 10-dihydroacridine, 0.924g of sodium carbonate, 12mL of ethanol, 24mL of water, and 0.11g of tetrakis (triphenylphosphine) palladium (0) were charged, and the mixture was degassed under reduced pressure. The reaction was carried out at 75℃for 3 hours with stirring. After cooling the reaction mixture to 25℃180mL of chloroform was added thereto, 60mL of water was stirred, and the organic layer was extracted. The organic layer was dried over sodium sulfate and concentrated under reduced pressure to give a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: hexane/toluene=5/1 (volume ratio)), and 0.972g of the obtained red-black oil was brominated by a conventional method to obtain 0.988g of a bromine compound represented by the above formula (13).

To a nitrogen-substituted reaction vessel, 0.066g of 4-formylphenylboronic acid, 0.494g of a bromine compound represented by the above formula (13), 20mL of dioxane, 4mL of water, 0.469g of tripotassium phosphate and 0.009g of 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl were added, and the mixture was stirred, and then the mixture was subjected to repeated 5 times of pressure reduction, degassing and nitrogen substitution in the reaction vessel. Then, 0.005g of palladium acetate was added, and the pressure reduction, degassing and nitrogen substitution were repeated 5 times in the reaction vessel. Then, the mixture was stirred at 60℃for 2 hours. After cooling the reaction mixture to 25 ℃, 90mL of chloroform was added, 30mL of water was stirred, and the organic layer was extracted. The organic layer was dried over sodium sulfate and concentrated under reduced pressure to give a crude product. The crude product was purified by a column chromatography (carrier: silica gel, eluent: toluene/hexane=1/1 (volume ratio)), and dried to obtain a red-black solid (0.299 g) of the formyl compound represented by the above formula (14).

To a nitrogen-substituted reaction vessel, 0.149g of the formyl compound represented by the above formula (14), 0.198g of cyanoacetic acid, 13mL of acetic acid and 0.024g of ammonium acetate were added, and the mixture was stirred at 100℃for 7 hours. After cooling the reaction mixture to 25 ℃,70 mL of water was added thereto and stirred, and the organic layer was extracted. The organic layer was washed with water and saturated brine in this order and dried to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: chloroform/methanol=10/1 (volume ratio)) and dried to give the objective sensitizing dye as a black solid (0.127 g, yield 81%).

The obtained black solid was analyzed by NMR, the following 65 hydrogen signals were detected, and the structure represented by the following formula (D-20) was identified (no hydrogen in the carboxyl group was observed).

¹H-NMR(400MHz,DMSO-d₆):δ(ppm)＝0.75-0.79(6H),0.97-1.01(4H),1.10-1.18(12H),1.91-1.98(4H),6.54-6.65(2H),7.08-7.17(5H),7.27-7.57(17H),7.66-7.70(2H),7.78-7.87(6H),7.97-8.03(4H),8.09-8.19(3H).

[ 52]

Synthesis example 2 Synthesis of sensitizing dye (D-19)

Into a nitrogen-substituted reaction vessel, 0.401g of the formyl compound represented by the above formula (14), 0.094g of indanone compound represented by the following formula (15), 5.7mL of acetic acid and 14.5mL of toluene were charged, and stirred at 90℃for 8 hours. After cooling the reaction mixture to 25 ℃, 50mL of toluene was added thereto and stirred, and the organic layer was extracted. The organic layer was washed with water and saturated brine in this order and dried to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: chloroform/methanol=10/1 (volume ratio)) and dried to give the objective sensitizing dye as a black-violet solid (0.328 g, yield 71%).

[ 53]

The obtained black-violet solid was analyzed by NMR, and the following 68 hydrogen signals were measured, and the structure represented by the following formula (D-19) (hydrogen in the carboxyl group was not observed) was identified.

¹H-NMR(400MHz,THF-d₈):δ(ppm)＝0.82-0.90(6H),1.15-1.27(16H),2.07-2.15(4H),6.68-6.77(2H),7.20-7.30(5H),7.30-7.42(11H),7.40-7.48(4H),7.51-7.59(2H),7.62-7.68(1H),7.77-7.83(4H),7.91-8.01(6H),8.02-8.08(1H),8.06-8.17(1H),8.24-8.28(1H),8.50-8.56(1H),8.57-8.65(1H),8.70-8.76(2H).

[ 54]

Synthesis example 3 Synthesis of sensitizing dye (D-18)

To a nitrogen-substituted reaction vessel, 0.319g of the bromine compound represented by the above formula (13), 0.138g of 4-acetylene benzoic acid, 10mL of super-dehydrated tetrahydrofuran, and 1.5mL of triethylamine after drying were added, and the reaction vessel was repeatedly depressurized, deaerated and nitrogen-substituted 5 times. Then, 0.053g of tetrakis (triphenylphosphine) palladium (0) and 0.009g of copper iodide were added, and the reaction vessel was repeatedly depressurized, deaerated and replaced with nitrogen gas 5 times. Thereafter, the mixture was stirred at 70℃for 3 hours. The reaction solution was cooled to 25℃and concentrated under reduced pressure to give a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: chloroform) and dried to give the objective sensitizing dye as a black-red solid (0.317 g, yield 69%).

The obtained black-red solid was analyzed by NMR, the following 64 hydrogen signals were detected, and the structure represented by the following formula (D-18) was identified (no hydrogen in the carboxyl group was observed).

¹H-NMR(400MHz,THF-d₈):δ(ppm)＝0.83-0.91(6H),1.10-1.15(4H),1.19-1.31(12H),2.01-2.09(4H),6.67-6.77(2H),7.20-7.29(5H),7.29-7.41(11H),7.41-7.46(4H),7.51-7.58(3H),7.62-7.68(3H),7.69-7.78(1H),7.78-7.84(3H),7.90-8.02(3H),8.01-8.07(1H),8.05-8.13(1H),8.21-8.26(1H).

[ 55]

Synthesis example 4 Synthesis of sensitizing dye (D-26)

To a nitrogen-substituted reaction vessel, 0.720g of 10-biphenyl-9, 9-biphenyl-7- (4, 5-tetramethyl-1, 3, 2-dioxaborane-2-yl) -2-phenyl-9, 10-dihydroacridine, 0.335g of 4, 7-dibromobenzene [ c ] [1,2,5] thiadiazole, 1.32g of sodium carbonate, 21mL of ethanol and 41mL of water were charged, and the reaction vessel was repeated 5 times with pressure reduction, degassing and nitrogen substitution. 0.141g of tetrakis (triphenylphosphine) palladium (0) was added, and the reaction vessel was then subjected to pressure reduction, degassing, and nitrogen substitution 5 times. The reaction was carried out at 75℃for 3 hours with stirring. After cooling the reaction mixture to 25 ℃, 30mL of toluene was added thereto and stirred, and the organic layer was extracted. The organic layer was dried over sodium sulfate and concentrated under reduced pressure to give a crude product. The crude product was purified by a column chromatography (carrier: silica gel, eluent: hexane/toluene=5/1 (volume ratio)) to obtain 0.520g of a bromine compound represented by the following formula (16).

[ 56]

To the nitrogen-substituted reaction vessel, 0.482g of the bromine compound represented by the above formula (16), 0.085g of 4-ethynylbenzoic acid, 15mL of super dehydrated tetrahydrofuran, 2.2mL of dried triethylamine were added, and the reaction vessel was repeated 5 times with reduced pressure, deaeration and nitrogen substitution. Then, 0.128g of tetrakis (triphenylphosphine) palladium (0) and 0.021g of copper iodide were added, and the reaction vessel was repeatedly depressurized, degassed, and purged with nitrogen 5 times. After that, stirring was carried out at 65℃for 4 hours. The reaction solution was cooled to 25℃and concentrated under reduced pressure to give a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: chloroform/methanol=10/1 (volume ratio)) and dried to give the objective sensitizing dye as a red solid (0.243 g, yield 49%).

The obtained red solid was analyzed by NMR, and the following 36 hydrogen signals were detected, and the structure represented by the following formula (D-26) was identified (hydrogen in the carboxyl group was not observed).

¹H-NMR(400MHz,THF-d₈):δ(ppm)＝6.54-6.65(2H),7.05-7.10(1H),7.09-7.15(4H),7.24-7.58(17H),7.67-7.77(4H),7.78-7.86(3H),7.97-8.04(5H).

[ 57]

EXAMPLE 1 evaluation of Properties

A titanium oxide paste (PST-18 NR manufactured by Nitro catalyst Co., ltd.) was applied to a glass substrate coated with a fluorine-doped tin oxide film by a doctor blade method. After drying at 110℃for 1 hour, the mixture was baked at 450℃for 30 minutes to obtain a titanium oxide thin film having a film thickness of 6. Mu.m. Next, the sensitizing dye (D-20) obtained in synthesis example 1 was dissolved in a mixed solution of acetonitrile/t-butanol=1/1 (volume ratio), to prepare 50mL of a solution having a concentration of 100 μm, and in the solution, a glass substrate coated with sintered titanium oxide was immersed at 25±2 ℃ for 15 hours to adsorb the dye, and used as a photoelectrode.

A platinum thin film having a film thickness of 15nm was formed on a glass substrate coated with a fluorine-doped tin oxide thin film by a sputtering method using an automatic fine coater (JFC-1600 manufactured by Japanese electric Co., ltd.) and used as a counter electrode.

Next, a spacer (thermally fused film) having a thickness of 60 μm was interposed between the photoelectrode and the counter electrode, and bonded by thermal fusion, and after the electrolyte (0.1M lithium iodide, 0.6M dimethylpropylimidazole iodide, 0.05M iodine, 0.5M 4-tert-butylpyridine)/3-methoxypropionitrile solution) was injected from the hole of the counter electrode, the hole was sealed, to produce a photoelectric conversion element.

Light generated by an artificial solar light irradiation device (OTENTO-SUN III type manufactured by spectrometer corporation) was irradiated from the photoelectrode side of the photoelectric conversion element, and the current-voltage characteristics were measured using a source meter (2400-type universal source meter manufactured by KEITHLEY). The intensity of the light was adjusted to 100mW/cm ². The measurement results and initial photoelectric conversion efficiencies obtained are shown in table 1.

Example 2 and example 3

A photoelectric conversion element was produced in the same manner as in example 1, except that the sensitizing dye shown in table 1 was used as the sensitizing dye for photoelectric conversion in place of the sensitizing dye (D-20) obtained in synthesis example 1. Table 1 summarizes the current-voltage characteristics, initial photoelectric conversion efficiency, of the photoelectric conversion element.

Comparative example 1 and comparative example 2 evaluation of characteristics

A photoelectric conversion element was produced in the same manner as in example 1, except that the sensitizing dyes shown in (E-1) and (E-2) which do not belong to the present invention were used instead of (D-20). The measurement results of the current-voltage characteristics of the photoelectric conversion element and the initial photoelectric conversion efficiency are shown in table 1.

[ 58]

TABLE 1

By using the photosensitizing dye composition for photoelectric conversion containing the photosensitizing dye of the present invention, a photoelectric conversion element having high photoelectric conversion efficiency and capable of maintaining photoelectric conversion efficiency even when light is irradiated for a long period of time can be obtained. On the other hand, the photoelectric conversion efficiency of the photoelectric conversion element using the dye for sensitized photoelectric conversion of the comparative example was insufficient.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Furthermore, the present application is based on Japanese patent application (Japanese patent application 2020-33131) filed on 28 months of 2020, which is incorporated herein by reference in its entirety. In addition, all references cited herein are incorporated as a whole.

(Industrial applicability)

The sensitizing dye and the sensitizing dye composition for photoelectric conversion comprising the same according to the present invention are useful for a photoelectric conversion element and a dye sensitized solar cell having high efficiency and high durability, and can provide clean energy as a solar cell capable of effectively converting solar energy into electric energy.

Claims

1. A sensitizing dye represented by the following general formula (1),

Wherein R ⁰ represents an aryl group having 6 to 36 carbon atoms which may have a substituent,

R ¹～R⁴ are the same or different and represent a hydrogen atom or a phenyl group which may have a substituent,

R ¹～R⁴ can bond to each other between adjacent groups to form a ring,

X represents CR ⁵R⁶,R⁵、R⁶ which are the same or different and each represents an aryl group having 6 to 36 carbon atoms which may have a substituent,

A is a 1-valent group represented by the following general formula (3) or (4),

Wherein R ²² and R ²⁴ represent carboxyl groups, R ²³ and R ²⁵ represent hydrogen atoms,

B is a 2-valent bond group or a single bond represented by the following general formula (5),

Wherein Z represents a carbon atom or a silicon atom,

Or an aryl group having 6 to 36 carbon atoms which may have a substituent,

R ³² to R ³⁷ are the same or different and represent a hydrogen atom,

P, q represent 0 or 1, r represents 0,

The substituents in the general formula (1) are:

An alkoxy group; or alternatively

Aryl groups having 6 to 30 carbon atoms.

2. A sensitizing dye as claimed in claim 1, wherein,

In the general formula (1), R ¹、R²、R⁴ is the same or different and represents a hydrogen atom or a phenyl group, and R ³ represents a hydrogen atom or a phenyl group which may have a substituent.

3. A sensitizing dye as claimed in claim 2, wherein,

In the general formula (1), R ¹～R⁴ is the same or different and represents a hydrogen atom or a phenyl group.

4. A sensitizing dye as claimed in claim 3, wherein,

In the general formula (1), R ¹、R²、R⁴ is the same or different and represents a hydrogen atom, and R ³ represents a hydrogen atom or a phenyl group.

5. A sensitizing dye according to any one of claims 1 to 4, wherein,

In the general formula (1) described above,

X is CR ⁵R⁶, and the X is CR ⁵R⁶,

R ⁵、R⁶ represents a phenyl group.

6. A sensitizing dye composition for photoelectric conversion comprising the sensitizing dye of any one of claims 1 to 5.

7. A photoelectric conversion element using the photosensitizing dye composition for photoelectric conversion according to claim 6.

8. A dye-sensitized solar cell using the photoelectric conversion element according to claim 7.