JP2005123013A - Semiconductor for photoelectric conversion material, photoelectric conversion element and solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide semiconductor for photoelectric conversion material, a photoelectric conversion element and solar cell, which has high photoelectric efficiency and excellent stability. <P>SOLUTION: A semiconductor for photoelectric conversion material is characterized to contain a coloring matter expressed by general formula 1. In the formula, A expresses an aromatic ring which may have substituent or heterocycle group, R<SB>1</SB>and R<SB>2</SB>each express hydrogen atom or substituent which bond together mutually to form a cyclic structure, M expresses hydrogen atom or salt formation nature cation, Y expresses -O- or -NR'-, R' expresses hydrogen atom or substituent, R expresses alkyl or aryl group, and n is integer of 0 to 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor for a photoelectric conversion material, a photoelectric conversion element, and a solar cell.

  A photoelectric conversion material is a material that converts light energy into electrical energy using an electrochemical reaction between electrodes. When the photoelectric conversion material is irradiated with light, electrons are generated on one electrode side and move to the counter electrode. The electrons that have moved to the counter electrode move as ions in the electrolyte and return to one electrode.

  That is, the photoelectric conversion material is a material that can continuously extract light energy as electric energy, and is used for, for example, a solar cell. There are several types of solar cells, but most of them are silicon solar cells that have been put to practical use in power generation panels for home installation, desk calculators, watches, portable game machines, and the like.

  However, recently, dye-sensitized solar cells have attracted attention and are being studied for practical use. Dye-sensitized solar cells have been studied for a long time, and the basic structure specifically includes a metal oxide semiconductor, a dye adsorbed thereon, an electrolyte solution, and a counter electrode.

  In the conventional dye-sensitized solar cell as described above, a photoelectric conversion material in which a spectral sensitizing dye having absorption in the visible light region is adsorbed on a semiconductor surface is used. For example, a solar cell having a spectral sensitizing dye layer such as a transition metal complex on the surface of a metal oxide semiconductor is described (for example, see Patent Document 1), and a titanium oxide semiconductor doped with metal ions Examples include those describing solar cells having a spectral sensitizing dye layer such as a transition metal complex on the surface of the layer (for example, see Patent Document 2).

On the other hand, as an oxide semiconductor electrode having photoelectric conversion ability, a semiconductor single crystal electrode has been used in the early days. The types include titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), and the like.

  However, since the single crystal electrode has a small amount of dye adsorption, the efficiency is very low and the cost is high. Thus, a high surface area semiconductor electrode having a large number of pores formed by sintering fine particles has been devised.

  For example, it has been reported by Tsubomura et al. That a porous zinc oxide electrode adsorbing an organic dye has very high performance (see, for example, Nature, 261 (1976) p402).

  After that, the dye has also been improved, and Graetzel et al. Have adsorbed the ruthenium complex dye on the porous titanium oxide electrode, so that it now has the same performance as a silicon solar cell (for example, J. Am. Chem. Soc. 115 (1993) 6382.).

However, for practical use to replace silicon solar cells, higher energy conversion efficiency, higher short-circuit current, open-circuit voltage, and form factor are required than ever before. These technologies have been developed by using ZnO, TiO ₂ , zirconium oxide (ZrO ₂ ), niobium oxide (Nb ₂ O ₅ ) and the like as reported substances.

In addition, since dye-sensitized wet solar cells are much cheaper to manufacture than silicon solar cells, in the future, there is a possibility of replacing silicon solar cells used in the above-mentioned various products. In some cases, the characteristics of the solar cell according to each product are important. Among various characteristics of solar cells, the following are shown. Short circuit current 2. Open voltage Form factor 4. 4. Energy conversion efficiency The light absorption spectrum is important. The energy conversion efficiency of the solar cell is the biggest problem for solar cells, and its improvement has been strongly desired. As one of the technical problems affecting the efficiency, there is a demand for a sensitizing dye having the ability to efficiently transfer photoexcited electrons to a semiconductor. Of the various dyes studied so far, the ruthenium complex dyes have been found to have relatively excellent characteristics, but the dyes are expensive and ruthenium, the central metal of the complex, is a rare element. Therefore, organic dyes that can be supplied at a lower cost and more stably are more preferable. Many organic dyes have been studied so far because of such demands, but the photoelectric conversion efficiency is not yet sufficient, and there has been a demand for an organic dye that can constitute a photoelectric conversion element with higher conversion efficiency.

  In addition to ruthenium complex dyes, studies have been made and well-known are merocyanine dyes, xanthene dyes, coumarin dyes, acridine dyes, phenylmethane dyes, and the like.

For example, these dyes are known to be immobilized by adsorption or ester-like bonding to a hydroxyl group on titanium oxide using a carboxyl group or the like (Non-patent Document 1). As other means for immobilization, methods using a dye having a chlorosulfonic acid group, a hydroxamic acid group, a boronic acid group, a dicarboxylic acid group or a phosphoric acid group are disclosed (Patent Document 1, Patent Document 2). , Patent Document 3, Patent Document 4, and Patent Document 5) are often not sufficient in adsorption force. Further, Patent Document 6 describes a dye having a cyanoacetic acid moiety in the molecule, but the cyano group has a strong electron withdrawing property and has a drawback of greatly reducing the oxidation potential of the obtained dye. In addition, since none of the dyes has satisfactory performance, further development of dyes having strong adsorptive power and high efficiency up to a long wavelength region is desired.
JP 2003-7358 A JP 2003-7359 A JP 2002-75475 A JP 2000-299139 A Japanese Patent Application Laid-Open No. 11-86916 JP 2002-164089 A J. et al. Phys. Chem. B, 107, 4356-4363 (2003)

  The first object of the present invention is to provide a semiconductor for a photoelectric conversion material, a photoelectric conversion element, and a solar cell that exhibit high photoelectric conversion efficiency and excellent stability.

The above object of the present invention has been achieved by the following.
(Claim 1)
The semiconductor for photoelectric conversion materials characterized by including the pigment | dye represented by General formula (1).

(In the formula, A represents an aryl group or a heterocyclic group which may have a substituent, R ₁ and R ₂ represent a hydrogen atom or a substituent, and may combine with each other to form a cyclic structure; M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, R represents an alkyl or aryl group, and n represents 0 to 4 Is an integer.)
(Claim 2)
The semiconductor for photoelectric conversion materials characterized by including the pigment | dye represented by General formula (2).

(In the formula, A represents a heterocyclic group which may have a substituent, R _{1 to} R ₃ represent a hydrogen atom or a substituent, and R _{1 to} R ₃ bonded to each other to form a cyclic structure. M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, R represents an alkyl or aryl group, and n represents It is an integer from 1 to 4.)
(Claim 3)
The semiconductor for a photoelectric conversion material according to claim 1, wherein A in the general formula (1) is represented by the following general formula (3).

(Wherein, R ₄ and R ₅ are a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, may form a ring bonded to R ₆ or R _7, R ₄ and R ₅ are bonded to each other A heterocycle may be formed, and R _{6 to} R ₉ each represent a hydrogen atom or a substituent, and any two adjacent groups may be bonded to each other to form a ring, where * represents a bonding position. .)
(Claim 4)
The semiconductor for a photoelectric conversion material according to claim 1, wherein A in the general formula (1) is represented by the following general formula (4).

(In the formula, R ₁₀ and R ₁₁ each represent a hydrogen atom or a substituent, and may be bonded to each other to form a ring; m represents 0 to 4; Z represents an oxygen atom, a sulfur atom or NR ₁₂ ; R ₁₂ represents a hydrogen atom or a substituent, where * represents a bonding position.
(Claim 5)
The semiconductor for a photoelectric conversion material according to claim 2, wherein A in the general formula (2) is represented by the following general formula (5).

(In the formula, R ₁₃ represents a hydrogen atom or a substituent, R ₁₄ or R ₁₅ represents a hydrogen atom or a substituent, and each may be bonded to form a ring, and X represents an oxygen atom, a sulfur atom, or selenium. Represents an atom, NR ₁₆ or C (R ₁₇ ) R ₁₈ , R _{16 to} R ₁₈ represent a hydrogen atom or a substituent, and * represents a bonding position.
(Claim 6)
The semiconductor for a photoelectric conversion material according to claim 2, wherein A in the general formula (2) is represented by the following general formula (6).

(In the formula, R ₁₉ represents a hydrogen atom or an alkyl, aryl or heterocyclic group, R ₂₀ represents a hydrogen atom or a substituent, and each may be bonded to form a ring; p represents 0 to 4; Q represents 0 to 2. Note that * represents a bonding position.)
(Claim 7)
It is a metal oxide or a metal sulfide semiconductor, The semiconductor for photoelectric conversion materials of any one of Claims 1-6 characterized by the above-mentioned.
(Claim 8)
The photoelectric conversion element characterized by the layer containing the semiconductor for photoelectric conversion materials of any one of Claims 1-7 being provided on the electroconductive support body.
(Claim 9)
A solar cell comprising the photoelectric conversion element according to claim 8, a charge transfer layer, and a counter electrode.

  According to the present invention, it was possible to provide a semiconductor for a photoelectric conversion material, a photoelectric conversion element, and a solar cell that exhibit high photoelectric conversion efficiency and excellent stability.

  Hereinafter, the best mode for carrying out the present invention will be described, but the present invention is not limited thereto.

  As a result of intensive studies to solve the above problems, the present inventors have described the general formulas (1), (2), and (3) to (6) described in claims 1 to 6, respectively. A semiconductor for photoelectric conversion material that exhibits the effects described in the present invention, that is, high photoelectric conversion efficiency and excellent stability, by a semiconductor for photoelectric conversion material sensitized using a compound having a specific structure as shown Succeeded in getting.

<< Semiconductor for photoelectric conversion material >>
As a semiconductor used for the semiconductor for a photoelectric conversion material of the present invention, a simple substance such as silicon or germanium, a group 3 to group 5 of a periodic table (also referred to as an element periodic table), or a group 13 to group 15 system. A compound having an element, a metal chalcogenide (eg, an oxide, sulfide, selenide, etc.), a metal nitride, or the like can be used.

  Preferred metal chalcogenides include titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum oxides, cadmium, zinc, lead, silver, antimony or Bismuth sulfide, cadmium or lead selenide, cadmium telluride and the like. Other compound semiconductors include phosphides such as zinc, gallium, indium and cadmium, gallium-arsenic or copper-indium selenide, copper-indium sulfide, titanium nitride, and the like.

Specific examples of the semiconductor according to the semiconductor for photoelectric conversion material of the present invention include TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , CdS, ZnS, PbS, Bi ₂ S ₃ , CdSe. , CdTe, GaP, InP, GaAs, CuInS ₂ , CuInSe ₂ , Ti ₃ N _4, etc., but TiO ₂ , ZnO, SnO ₂ , Fe ₂ O ₃ , WO ₃ , Nb ₂ O are preferably used. ₅ , CdS, and PbS, and preferably used are metal oxides or metal sulfide semiconductors. Of these, a metal oxide semiconductor is more preferably used, and among them, TiO ₂ or Nb ₂ O ₅ is used, and TiO ₂ is more preferably used.

The semiconductor used for the photoelectric conversion material semiconductor of the present invention may be a combination of the above-described plurality of semiconductors. For example, several types of metal oxides or metal sulfides described above can be used in combination, or 20% by mass of titanium nitride (Ti ₃ N ₄ ) may be mixed and used in the titanium oxide semiconductor. In addition, J.H. Chem. Soc. , Chem. Commun. 15 (1999). At this time, when a component is added as a semiconductor in addition to the metal oxide or metal sulfide, the mass ratio of the additional component to the metal oxide or metal sulfide semiconductor is preferably 30% or less.

  By sensitizing the semiconductor for photoelectric conversion material with any one compound represented by the general formulas (1), (2) and (3) to (6), the object described in the present invention It is possible to obtain a semiconductor for a photoelectric conversion material according to the present invention that exhibits high photoelectric conversion efficiency and excellent stability.

  Hereinafter, the compounds represented by the general formulas (1) to (6) will be described.

<< Compound Represented by Formula (1) >>
The compound represented by the general formula (1) according to the present invention will be described.
A represents an aryl group or a heterocyclic group which may have a substituent, R ₁ and R ₂ represent a hydrogen atom or a substituent, and may be bonded to each other to form a cyclic structure. The structure may be either an aliphatic ring or an aromatic ring, and may be a hydrocarbon ring or a heterocyclic ring. The ring formed by combining R ₁ and R ₂ may also be substituted with a substituent described later, or may be further condensed with another ring structure. Further, when n is 1 or more, R ₁ and R ₂ which are repeating units may be different from each other, and a ring may be formed between R ₁ or R ₂ of adjacent repeating units.

  M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, R represents alkyl or aryl, and n represents 0 to 4 Is an integer.

  In the general formula (1), examples of the aryl group represented by A include a phenyl group, a naphthyl group, a p-tolyl group, an m-chlorophenyl group, and an o-hexadecanoylaminophenyl group.

  In the general formula (1), the heterocyclic group represented by A can be a group derived from various conventionally known heterocyclic rings. Moreover, the hetero atom contained in this heterocyclic ring can be an oxygen atom, a sulfur atom, a nitrogen atom, etc., and the number of the hetero atoms contained in the ring is one or more (2-5) . When two or more heteroatoms are included in the ring, the heteroatoms may be the same or different. Further, the heterocyclic ring is condensed with a carbocyclic ring having 6 to 12 carbon atoms such as a benzene ring, a naphthalene ring or a cyclohexane ring, or another heterocyclic ring having 5 to 12 ring constituent elements (for example, a julolidine ring). May be. Specific examples of the heterocyclic ring include thiazole, benzothiazole, oxazole, benzoxazole, selenazole, benzoselenazole, indole, coumarin, phenylxanthene, thiophene, furan, imidazole and the like. Further, it may be substituted with the following substituents.

  The substituent is not particularly limited as long as it can be substituted. For example, an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group) Group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), bicycloalkyl group (eg, bicyclo [1,2,2] heptan-2-yl group, bicyclo [ 2,2,2] octane-3-yl group), alkenyl group (for example, vinyl group, allyl group, prenyl group, octenyl group, etc.), cycloalkenyl group (for example, 2-cyclopenten-1-yl group) , 2-cyclohexen-1-yl group, etc.), bicycloalkenyl group (for example, bicyclo [2,2,1] hept 2-ene-1-yl group, bicyclo [2,2,2] oct-2-en-4-yl group, etc.), alkynyl group (for example, propargyl group, ethynyl group, trimethylsilylethynyl group, etc.), aryl group ( For example, phenyl group, naphthyl group, p-tolyl group, m-chlorophenyl group, o-hexadecanoylaminophenyl group, etc.), heterocyclic group (for example, pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, furyl group, Pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group, sulfolanyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, etc.), heterocyclic oxy group (for example, 1-phenyltetrazol-5-oxy group, 2-tetrahydropyrani group) Ruoxy group, pyridyloxy group, thiazolyloxy group, oxazolyloxy group Imidazolyloxy group, etc.), halogen atoms (eg chlorine atom, bromine atom, iodine atom, fluorine atom etc.), alkoxyl groups (eg methoxy group, ethoxy group, propyloxy group, tert-butoxy group, pentyloxy group, hexyl) Oxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxyl group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (for example, phenoxy group, naphthyloxy group, 2-methylphenoxy group, 4- tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.) , Shik Loroalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, phenylthio group, naphthylthio group, etc.), heterocyclic thio group (for example, pyridylthio group, thiazolylthio group, oxazolylthio group, imidazolylthio group, furylthio group) Group, pyrrolylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl) Group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexyla) Nosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, Pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl) Group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridyl Such as formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy, ethylcarbonyloxy, butylcarbonyloxy, octylcarbonyloxy Group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), acylamino group (for example, acetylamino group, ethylcarbonylamino group, propionylamino group, butanamide group, hexaneamide group, 2-ethylhexylcarbonylamino group, cyclohexylcarbonylamino group) Dimethylcarbonylamino group, benzoylamino group, naphthylcarbonylamino group formylamino group, pivaloylamino group, lauroylamino group, 3,4,5-tri-n -Octyloxyphenylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2 -Ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), alkylsulfinyl group or arylsulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group) Cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthy Sulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group or arylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group) , Naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, methylamino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group) Anilino group, N-methylanilino group, diphenylamino group, naphthylamino group, 2-pyridylamino group, etc.), silyloxy group (for example, trimethylsilyloxy group, tert-butyldimethylsilylo group) ) Group, aminocarbonyloxy group (for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, N -N-octylcarbamoyloxy group etc.), alkoxycarbonyloxy group (eg methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyloxy group etc.), aryloxycarbonyloxy group (eg , Phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group, etc.), alkoxycarbonylamino group (for example, methoxycarbonylamino group, ethoxycarbonyl) Ruamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group, etc.), aryloxycarbonylamino group (for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, m-n-octyloxyphenoxycarbonylamino group, etc.), sulfamoylamino groups (eg, sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group, etc.), mercapto Group, arylazo group (for example, phenylazo group, naphthylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), heterocyclic azo group (for example, pyridylazo group, thiazolylazo group) The Sazolylazo group, imidazolylazo group, furylazo group, pyrrolylazo group), imino group (for example, N-succinimido-1-yl group, N-phthalimido-1-yl group, etc.), phosphino group (for example, dimethylphosphino group, diphenyl) Phosphino group, methylphenoxyphosphino group, etc.), phosphinyl group (eg, phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group, etc.), phosphinyloxy group (eg, diphenoxyphosphinyloxy) Group, dioctyloxyphosphinyloxy group, etc.), phosphinylamino group (eg, dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, etc.), silyl group (eg, trimethylsilyl group, tert-butyldimethylsilyl group) Group, phenyldimethylsilyl group, etc.) A cyano group, a nitro group, a hydroxyl group, a sulfo group, a carboxyl group.

  A is preferably an aryl group as represented by the general formula (3) or a heterocyclic group as represented by the general formula (4).

R ₁ and R ₂ are preferably a hydrogen atom or an alkyl group, a halogen atom, an alkoxy group, a cyano group, an amino group, etc., more preferably a hydrogen atom, an alkyl group, a halogen atom or an alkoxy group, which are bonded to each other. It is also preferable to form a 5- or 6-membered cyclic structure (for example, a thiophene ring, a cyclohexene ring, etc.).

  M is preferably a hydrogen atom or a salt-forming cation, and more preferably a hydrogen atom.

  R ′ includes a hydrogen atom or the above-mentioned substituent, and is preferably a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and more preferably a hydrogen atom. N is preferably an integer of 1 to 4, more preferably an integer of 2 to 4.

  R represents alkyl (for example, methyl group, ethyl group, etc.), aryl (for example, phenyl group, chlorophenyl group, etc.) or a heterocyclic group (representing the same group as the heterocyclic group in the group represented by A). However, R is preferably an alkyl group or an aryl group, and each may be substituted with a group similar to the above-described substituent.

<< Compound Represented by Formula (2) >>
Next, general formula (2) will be described.

In the general formula (2) A represents a heterocyclic group which may have a substituent, R ₁ to R ₃ represents a hydrogen atom or a substituent, R ₁ to R ₃ are joined to form a cyclic structure Alternatively, the ring structure formed may be either an aliphatic ring or an aromatic ring, and may be a hydrocarbon ring or a heterocyclic ring. The ring formed by combining R ₁ and R ₂ , R ₂ and R _3, and R ₁ and R ₃ may be substituted with the above substituents, or may be condensed with another ring structure. Also good. M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, and n is an integer of 0 to 4.

  The heterocyclic group represented by A here is synonymous with the heterocyclic ring in General formula (1).

Moreover, R < ₁ > -R < ₃ >, M, Y, R ', R and a substituent are synonymous with General formula (1).

  In the general formula (2), A is preferably a heterocyclic group represented by the general formula (5) or (6).

R ₁ , R ₂ and R ₃ are preferably a hydrogen atom or an alkyl group, a halogen atom, a cyano group, an amino group, etc., more preferably a hydrogen atom, an alkyl group or a halogen atom, It is also preferable to form a 6-membered cyclic structure (for example, a thiophene ring, a cyclohexene ring, etc.).

  M is preferably a hydrogen atom or a salt-forming cation, and more preferably a hydrogen atom.

  R ′ is preferably a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and more preferably a hydrogen atom. n is preferably 1 to 3.

  In the compound represented by the general formula (1), in the formula, A is preferably represented by the general formula (3). The general formula (3) will be described.

In the general formula (3), R ₄ and R ₅ represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and may combine with R ₆ or R ₇ to form a ring (eg, a julolidine ring). R _{6 to} R ₉ each represents a hydrogen atom or a substituent, and any two adjacent groups may be bonded to each other to form a ring (for example, a naphthalene ring).

  In the general formula (3), examples of the substituent include the groups described in the general formula (1). Preferred examples of the substituent include a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a carboxyl group, an alkoxy group, and an alkoxycarbonyl. Group, acyl group and the like. More preferably, they are a hydrogen atom, an alkyl group, an alkoxy group, and an acyl group.

R _{6 to} R ₉ are preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

Any two adjacent R _{6 to} R ₉ may be bonded to each other to form a ring structure. The formed ring structure may be either an aliphatic ring or an aromatic ring, which may be a hydrocarbon ring or a heterocyclic ring, and the formed ring is also substituted by the substituents shown above. It may be condensed with another ring structure.

R ₄ and R ₅ are preferably a hydrogen atom or an alkyl group.

  In the compound represented by the general formula (1), A is preferably represented by the general formula (4). The general formula (4) will be described.

In the general formula (4), R ₁₀ and R ₁₁ each represent a hydrogen atom or a substituent, and may be bonded to each other to form a ring. M represents 0 to 4 and is different when m is 1 or more. Z may represent an oxygen atom, a sulfur atom, or NR ₁₂ , and R ₁₂ represents a hydrogen atom or a substituent.

In the general formula (3), examples of the substituent include the groups described in the general formula (1), and R ₁₀ is preferably a hydrogen atom, a halogen atom, an alkyl group, a trifluoromethyl group, or the like.

R ₁₁ is preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a dialkylamino group, an alkoxy group or an acylamino group, more preferably a hydrogen atom, a halogen atom, an alkyl group, a dialkylamino group or an alkoxy group. . In addition, when m is 2 or more, it is also preferable that each bond to form a ring (for example, a julolidine ring).

Z is preferably an oxygen atom or NR ₁₂ , and R ₁₂ is preferably a hydrogen atom, an alkyl group or an aryl group.

  Next, in the compound represented by the general formula (2), in the formula, A is preferably represented by the general formula (5). The general formula (5) will be described.

In the general formula (5), R ₁₃ represents a hydrogen atom or a substituent, R ₁₄ or R ₁₅ represents a hydrogen atom or a substituent, and each may be bonded to form a ring, and X represents an oxygen atom or a sulfur atom. , Selenium atom, NR ₁₆ or C (R ₁₇ ) R ₁₈ , wherein R _{16 to} R ₁₈ represent a hydrogen atom or a substituent.

In the general formula (5), examples of the substituent include the groups described in the general formula (1). R ₁₃ is preferably a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group, more preferably a hydrogen atom. An atom, an alkyl group, and an aryl group.

R ₁₄ or R ₁₅ is preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, a cyano group or the like. R ₁₄ and R ₁₅ may combine with each other to form a ring structure. The ring structure formed may be either an aliphatic ring or an aromatic ring, and may be a hydrocarbon ring or a heterocyclic ring. The ring formed by combining R ₁₄ and R ₁₅ may also be substituted with the substituents shown above. R ₁₄ and R ₁₅ preferably form a ring, and more preferably form a benzene ring. Further, it preferably has a substituent, and an electron-withdrawing group (for example, a halogen atom, a cyano group, an alkoxycarbonyl group, a trifluoromethyl group, etc.) is preferably substituted.

X is preferably a sulfur atom, NR ₁₆ or C (R ₁₇ ) R ₁₈ , more preferably a sulfur atom or C (R ₁₇ ) R ₁₈ . R _{16 to} R ₁₇ are preferably a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.

  In the compound represented by the general formula (2), A is preferably represented by the general formula (6). The general formula (6) will be described.

In General Formula (6), R ₁₉ represents a hydrogen atom or an alkyl, aryl, or heterocyclic group, R ₂₀ represents a hydrogen atom or a substituent, and each may be bonded to form a ring, and p is 0 to 0. 4 may be different when p is 1 or more, and q represents 0-2.

In the general formula (6), examples of the substituent include the groups described in the general formula (1), and R ₁₉ is preferably a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.

R ₂₀ is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acylamino group, a dialkylamino group or the like.

  Specific examples of the compounds represented by the general formulas (1), (2) and (3) to (6) according to the present invention are shown below, but the present invention is not limited thereto.

  The compounds represented by the general formulas (1), (2) and (3) to (6) according to the present invention are disclosed in, for example, US Pat. Org. Chem. 53, 880, (1988), J. Am. Heterocycl. Chem. , 9, 315, (1972) and the like, and can be synthesized with reference to conventionally known methods.

  Specific examples of the synthesis method of the compound according to the present invention are shown below, but other compounds can be synthesized in the same manner, and the synthesis method is not limited thereto.

Synthesis Example 1; Synthesis of Exemplified Compound II-1 (1) Synthesis Route

(2) Synthesis of Exemplified Compound II-1 Addition of 25 ml of pyridine to 2.42 g of intermediate 1 and 0.80 g of intermediate 2 and heating reaction at 40 ° C. for 3 hours. Thereafter, pyridine is distilled off, and water and toluene are added for extraction. After neutralization and washing with water, the mixture was concentrated and recrystallized with MeOH to obtain 1.82 g of Exemplified Compound II-1. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

Synthesis Example 2; Synthesis of Exemplary Compound II-45 (1) Synthesis Route

(2) Synthesis of Exemplified Compound II-45 To 2.33 g of Intermediate 3 is added 50 ml of ethanol, 0.48 g of potassium acetate and 0.42 g of Intermediate 4 and heated to reflux for 1 hour. After the reaction is complete, cool to room temperature. The precipitated crystals were filtered, washed with ethanol and then ethyl acetate to obtain crude crystals, and then recrystallized with methanol to obtain 1.22 g of Exemplified Compound II-45. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

Synthesis Example 3; Synthesis of Exemplary Compound I-51 (1) Synthesis Route

(2) Synthesis of Exemplary Compound I-51 50 ml of toluene, 1.20 g of Intermediate 6 and 1.23 g of triethylamine are added to 3.45 g of Intermediate 5 and heated at 90 ° C. for 12 hours. After the reaction is complete, cool to room temperature. The precipitated crystals were filtered and then washed with ethyl acetate to obtain crude crystals, which were then recrystallized from methanol to obtain 2.12 g of Exemplified Compound I-51. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

<< Sensitivity treatment of semiconductor for photoelectric conversion material >>
The photoelectric conversion material semiconductor of the present invention is sensitized by containing any one compound represented by the general formulas (1), (2), and (3) to (6), and is described in the present invention. It is possible to achieve the effect. Here, including the compound includes various modes such as adsorption to the semiconductor surface, and when the semiconductor has a porous structure such as a porous structure, the compound enters the porous structure of the semiconductor.

Moreover, the total content of each compound represented by the general formulas (1), (2) and (3) to (6) per 1 m ² of the semiconductor layer (which may be a semiconductor) is 0.01 mmol to 100 The range of millimolar is preferable, more preferably 0.1 millimolar to 50 millimolar, and particularly preferably 0.5 millimolar to 20 millimolar.

  When sensitizing treatment is performed using any one compound represented by the general formulas (1), (2) and (3) to (6) according to the present invention, the compound may be used alone. It is also possible to use a combination of a plurality of compounds represented by the general formulas (1), (2) and (3) to (6) according to the present invention and other compounds (for example, US patents). 4,684,537, 4,927,721, 5,084,365, 5,350,644, 5,463,057 Nos. 5,525,440, etc., and compounds described in JP-A-7-249790, JP-A-2000-150007, etc.) can also be used as a mixture. .

  In particular, when the application of the semiconductor for photoelectric conversion material of the present invention is a solar cell described later, two types of absorption wavelengths are different so that the wavelength range of photoelectric conversion can be made as wide as possible to effectively use sunlight. It is preferable to use a mixture of the above dyes.

  In order for a semiconductor to contain any one compound represented by the general formulas (1), (2) and (3) to (6), the compound is dissolved in a suitable solvent (such as ethanol). A method of immersing a well-dried semiconductor in the solution for a long time is common.

  A semiconductor for a photoelectric conversion material in which a plurality of types of any one of the compounds represented by the general formulas (1), (2) and (3) to (6) are used together or in combination with other sensitizing dye compounds When preparing this, a mixed solution of each compound may be prepared and used. Alternatively, a solution may be prepared for each compound, and the mixture may be immersed in each solution in order. When preparing a separate solution for each compound and immersing in each solution in order, the effects described in the present invention can be obtained regardless of the order in which the semiconductor, the sensitizing dye, and the like are included in the semiconductor. be able to. Further, it may be produced by mixing semiconductor fine particles on which the compound is adsorbed alone.

  The adsorption treatment may be performed when the semiconductor is in the form of particles, or may be performed after forming a film on the support. The solution in which the compound used for the adsorption treatment is dissolved may be used at room temperature, or may be used by heating in a temperature range in which the compound does not decompose and the solution does not boil. Moreover, you may implement adsorption | suction of the said compound after application | coating of a semiconductor fine particle (after formation of a photosensitive layer) like manufacture of the photoelectric conversion element mentioned later. Moreover, you may implement adsorption | suction of the said compound by apply | coating a semiconductor fine particle and the said compound of this invention simultaneously. Unadsorbed compounds can be removed by washing.

  Moreover, about the sensitization process of the semiconductor for photoelectric conversion materials of this invention, the semiconductor contains any one compound represented by the said General formula (1), (2) and (3)-(6). The sensitization process is performed by the above-described process, and details of the sensitization process will be specifically described in the photoelectric conversion element described later.

  Further, in the case of a semiconductor for a photoelectric conversion material having a semiconductor thin film with a high porosity, the above compound or sensitization is performed before water is adsorbed on the semiconductor thin film and in the voids inside the semiconductor thin film by moisture, water vapor, etc. It is preferable to complete the adsorption treatment (sensitization treatment of a semiconductor for a photoelectric conversion material) such as a dye compound.

  You may surface-treat the semiconductor for photoelectric conversion materials of this invention using an organic base. Examples of the organic base include diarylamine, triarylamine, pyridine, 4-t-butylpyridine, polyvinylpyridine, quinoline, piperidine, amidine, and the like, among which pyridine, 4-t-butylpyridine, and polyvinylpyridine are preferable. .

  When the organic base is a liquid, it can be surface treated by preparing a solution dissolved in an organic solvent as it is, and immersing the semiconductor for a photoelectric conversion material of the present invention in a liquid amine or an amine solution. .

  Moreover, as a pigment | dye which can be used together with any one compound represented by the said General formula (1), (2) and (3)-(6) which concerns on this invention, it concerns on this invention. Any dye that can spectrally sensitize a semiconductor can be used. In order to increase the wavelength range of photoelectric conversion as much as possible and increase the conversion efficiency, it is preferable to mix two or more kinds of dyes. Moreover, the pigment | dye to mix and its ratio can be selected so that it may match with the wavelength range and intensity distribution of the target light source.

  Examples of the dye that can be used in combination with the compound according to the present invention include metal complex dyes, phthalocyanine dyes, porphyrin dyes, from a comprehensive viewpoint such as photoelectron transfer reaction activity, photo durability, and photochemical stability. Polymethine dyes are preferably used.

  Among the metal complex dyes, JP-A Nos. 2001-223037, 2001-226607, US Pat. Nos. 4,927,721, 4,684,537, 5,084,365, 5,350,644, 5,463,057, 5,525,440, JP-A-7-249750, JP 10-504512, World Patent 989/50393, etc. Ruthenium complex dyes are preferably used.

  Examples of the porphyrin dye and the phthalocyanine dye include dyes described in JP-A No. 2001-223037 as preferable dyes.

  Examples of the polymethine dye include conventionally known methine dyes, JP-A Nos. 11-35836, 11-158395, 11-163378, 11-214730, and 11-214731. 10-093118, 11-273754, JP-A-2000-106224, 2000-357809, 2001-052766, EP 892,411, 911,841, etc. Those described are mentioned.

<< Method for Manufacturing Semiconductor for Photoelectric Conversion Material >>
A method for manufacturing a semiconductor for a photoelectric conversion material of the present invention will be described.

  As one embodiment of the semiconductor for a photoelectric conversion material of the present invention, a method such as forming the above semiconductor for a photoelectric conversion material on a conductive support by firing is exemplified.

  When the semiconductor for a photoelectric conversion material of the present invention is produced by firing, the semiconductor is sensitized (adsorption, penetration into a porous layer, etc.) with the above-described compound or sensitizing dye after firing. It is preferable to do. It is particularly preferable to perform the compound adsorption treatment quickly after the firing and before the water is adsorbed to the semiconductor.

  When the semiconductor for photoelectric conversion materials of the present invention is in the form of particles, the semiconductor electrode is preferably prepared by applying or spraying the semiconductor for photoelectric conversion materials onto a conductive support. Moreover, when the semiconductor for photoelectric conversion materials of this invention is a film | membrane form, Comprising: It is not hold | maintained on an electroconductive support body, the semiconductor electrode for photoelectric conversion materials is bonded on an electroconductive support body, and a semiconductor electrode is attached. It is preferable to produce it.

  Hereinafter, a process for producing a semiconductor for a photoelectric conversion material of the present invention will be specifically described.

<< Preparation of coating liquid containing semiconductor fine powder >>
First, a coating solution containing fine semiconductor powder is prepared. The semiconductor fine powder preferably has a finer primary particle diameter, and the primary particle diameter is preferably 1 nm to 5000 nm, and more preferably 2 nm to 50 nm. The coating liquid containing the semiconductor fine powder can be prepared by dispersing the semiconductor fine powder in a solvent. The semiconductor fine powder dispersed in the solvent is dispersed in the form of primary particles. The solvent is not particularly limited as long as it can disperse the semiconductor fine powder.

  Examples of the solvent include water, an organic solvent, and a mixed solution of water and an organic solvent. As the organic solvent, alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone, acetone and acetyl acetone, hydrocarbons such as hexane and cyclohexane, and the like are used. A surfactant and a viscosity modifier (polyhydric alcohol such as polyethylene glycol) can be added to the coating solution as necessary. The range of the semiconductor fine powder concentration in the solvent is preferably 0.1% by mass to 70% by mass, and more preferably 0.1% by mass to 30% by mass.

<< Application of Semiconductor Fine Powder-Containing Coating Liquid and Firing Process of Formed Semiconductor Layer >>
The semiconductor fine powder-containing coating solution obtained as described above is applied or sprayed onto a conductive support, dried, etc., and then baked in air or in an inert gas, on the conductive support. A semiconductor layer (semiconductor film) is formed.

  The film obtained by applying and drying the coating liquid on the conductive support is composed of an aggregate of semiconductor fine particles, and the particle size of the fine particles corresponds to the primary particle size of the semiconductor fine powder used. is there.

  The semiconductor fine particle aggregate film formed on the substrate such as the conductive support in this way has a low bonding strength with the conductive support and a bonding strength between the fine particles and a low mechanical strength. Therefore, preferably, the semiconductor fine particle aggregate film is fired to increase the mechanical strength, thereby obtaining a fired product film firmly fixed to the substrate.

  In the present invention, the fired product film may have any structure, but is preferably a porous structure film (also referred to as a porous layer having voids).

  Here, the porosity of the semiconductor thin film according to the present invention is preferably 10% by volume or less, more preferably 8% by volume or less, and particularly preferably 0.01% by volume to 5% by volume. The porosity of the semiconductor thin film means a porosity that is penetrable in the thickness direction of the dielectric, and can be measured using a commercially available apparatus such as a mercury porosimeter (Shimadzu Polarizer 9220 type).

  The film thickness of the semiconductor layer that is a fired product film having a porous structure is preferably at least 10 nm or more, more preferably 100 nm to 10,000 nm.

  From the viewpoint of appropriately adjusting the actual surface area of the fired product film during the firing treatment and obtaining a fired product film having the above porosity, the firing temperature is preferably lower than 1000 ° C, more preferably 200 ° C to 800 ° C. It is the range of 300 degreeC, Most preferably, it is the range of 300 to 800 degreeC.

  Further, the ratio of the actual surface area to the apparent surface area can be controlled by the particle diameter and specific surface area of the semiconductor fine particles, the firing temperature, and the like. In addition, after heat treatment, for example, chemical plating or aqueous trichloride using a titanium tetrachloride aqueous solution is used to increase the surface area of the semiconductor particles, increase the purity in the vicinity of the semiconductor particles, and increase the efficiency of electron injection from the dye into the semiconductor particles. Electrochemical plating using a titanium aqueous solution may be performed.

<Semiconductor sensitization processing>
As described above, the semiconductor sensitization treatment is performed by dissolving the dye in an appropriate solvent and immersing the substrate obtained by firing the semiconductor in the solution. In that case, a substrate on which a semiconductor layer (also referred to as a semiconductor film) is formed by baking is subjected to pressure reduction treatment or heat treatment in advance to remove bubbles in the film, and the general formulas (1) and (2) It is preferable that any one of the compounds represented by (3) to (6) can enter deep inside the semiconductor layer (semiconductor film), and the semiconductor layer (semiconductor film) is a porous structure film. In some cases it is particularly preferred.

"solvent"
The solvent used to dissolve any one compound of the general formulas (1), (2), and (3) to (6) can dissolve the compound and dissolve the semiconductor. There is no particular limitation as long as it does not react with the semiconductor, but moisture and gas dissolved in the solvent enter the semiconductor film and prevent sensitizing treatment such as adsorption of the compound. In order to prevent this, it is preferable to deaerate and purify in advance.

  Solvents preferably used in dissolving the above compounds are alcohol solvents such as methanol, ethanol and n-propanol, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane. Solvents and halogenated hydrocarbon solvents such as methylene chloride and 1,1,2-trichloroethane, particularly preferably methanol, ethanol, acetone, methyl ethyl ketone, tetrahydrofuran and methylene chloride.

《Tensing temperature and time》
The time for immersing the substrate after baking the semiconductor in the solution containing any one compound represented by the general formulas (1), (2) and (3) to (6) is the semiconductor layer (semiconductor film). The compound penetrates deeply into the surface to sufficiently advance adsorption, etc., sufficiently sensitizes the semiconductor, and prevents decomposition products generated by decomposition of the compound in the solution from interfering with the adsorption of the compound. From the viewpoint of achieving the above, it is preferably 3 hours to 48 hours, more preferably 4 hours to 24 hours, at 25 ° C. This effect is particularly remarkable when the semiconductor film is a porous structure film. However, the immersion time is a value under the condition of 25 ° C., and is not limited to the above when the temperature condition is changed.

  In soaking, the solution containing any one compound represented by the general formulas (1), (2) and (3) to (6) should be kept at a temperature that does not boil unless the compound is decomposed. It may be used after heating. A preferable temperature range is 10 ° C to 100 ° C, and more preferably 25 ° C to 80 ° C. However, as described above, this is not the case when the solvent boils in the temperature range.

<< Photoelectric conversion element >>
The photoelectric conversion element of this invention is demonstrated using FIG.

  FIG. 1 is a partial cross-sectional view showing an example of the structure of the photoelectric conversion element of the present invention.

  Reference numeral 1 denotes a conductive support, 2 denotes a photosensitive layer, 3 denotes a charge transfer layer, and 4 denotes a counter electrode. The conductive support 1 and the photosensitive layer 2 are also collectively referred to as a semiconductor electrode.

  Here, the photosensitive layer 2 is a layer having the semiconductor for a photoelectric conversion material of the present invention, and the charge transfer layer 3 usually contains a redox electrolyte and is in contact with the conductive support 1, the photosensitive layer 2, and the counter electrode 4. Used in form.

<< Method for Manufacturing Photoelectric Conversion Element >>
The manufacturing method of a photoelectric conversion element is demonstrated using FIG.

  The photoelectric conversion element of the present invention is obtained by forming the semiconductor thin film on the conductive support 1 as shown in FIG. 1 using the plasma processing apparatus as described above, and then the general formula (1) according to the present invention. , (2) and (3) to (6) are produced through a process of adsorbing any one compound represented by (6).

  Further, the surface area of the semiconductor thin film is increased or impurities on the surface of the semiconductor thin film are removed to increase the purity of the semiconductor, which is represented by the general formulas (1), (2) and (3) to (6). For example, chemical plating using a titanium tetrachloride aqueous solution or electrochemical plating using a titanium trichloride aqueous solution may be performed for the purpose of increasing the efficiency of electron injection from any one compound into the semiconductor. In order to obtain the same effect, carboxylic acids (acetic acid, propionic acid, hexanoic acid, benzoic acid, etc.) may be adsorbed on the semiconductor surface after dye adsorption.

  The semiconductor film formed on the conductive support 1 adsorbs any one of the compounds represented by the general formulas (1), (2) and (3) to (6) described above to form a semiconductor film Is sensitized to form the photosensitive layer 2. As described above, the sensitizing treatment method is performed by dissolving the compound in an appropriate solvent and immersing the semiconductor film formed on the conductive support 1 in the solution. In that case, the semiconductor film is preliminarily subjected to pressure reduction treatment or heat treatment to remove bubbles in the film, and any one of the general formulas (1), (2) and (3) to (6) is represented. It is preferable that the above compound can enter deep inside the semiconductor film.

  When adsorbing any one compound represented by the general formulas (1), (2) and (3) to (6) to the semiconductor according to the present invention, it may be used alone, A plurality may be used in combination. Furthermore, conventionally known sensitizing dye compounds (for example, U.S. Pat. Nos. 4,684,537, 4,927,721, 5,084,365, 5,350,644, No. 5,463,057, 5,525,440, JP-A-7-249790, JP-A-2000-150007, etc.) may be mixed and adsorbed.

  The compound to be used in combination may be prepared by immersing in a solution prepared by mixing, or may be prepared by preparing separate solutions for each compound and immersing in each solution in turn. The effect of the present invention can be obtained regardless of the order in which the compound and the conventionally known sensitizing dye are adsorbed on the semiconductor.

  For the adsorption treatment, a solution in which the compound is dissolved may be used at room temperature, or the solution may be heated to a temperature that does not affect the compound. Furthermore, it is preferable to remove the dye that has not been adsorbed during the adsorption treatment by washing treatment with a solvent or the like.

  After the dye is adsorbed to the semiconductor film formed on the conductive support 1 to form the photosensitive layer 2, the counter electrode 4 is disposed so as to face the photosensitive layer 2. Further, a redox electrolyte as a charge transfer layer is injected between the semiconductor electrode and the counter electrode 4 to obtain a photoelectric conversion element.

《Solar cell》
The solar cell of the present invention will be described.

  As shown in FIG. 1, the solar cell of the present invention is optimally designed for sunlight and circuit design as one aspect of the photoelectric conversion element of the present invention, and is optimal when sunlight is used as a light source. It has a structure in which photoelectric conversion is performed. That is, the semiconductor for photoelectric conversion material has a structure that can be irradiated with sunlight. When constituting the solar cell of the present invention, it is preferable that the semiconductor electrode, the charge transfer layer and the counter electrode are housed in a case and sealed, or the whole is sealed with resin.

  When the solar cell of the present invention is irradiated with sunlight or an electromagnetic wave equivalent to sunlight, the compound of the present invention adsorbed on the semiconductor for photoelectric conversion material absorbs the irradiated light or electromagnetic wave and excites it. Electrons generated by excitation move to the semiconductor, and then move to the counter electrode 4 via the conductive support 1 to reduce the redox electrolyte of the charge transfer layer 3. On the other hand, the compound of the present invention in which electrons are transferred to a semiconductor is an oxidant, but is reduced by the supply of electrons from the counter electrode 4 via the redox electrolyte of the charge transfer layer 3 and is reduced to the original. At the same time, the redox electrolyte of the charge transfer layer 3 is oxidized and returned to a state where it can be reduced again by the electrons supplied from the counter electrode 4. In this way, electrons flow, and a solar cell using the photoelectric conversion element of the present invention can be configured.

<Conductive support>
The conductive support used in the photoelectric conversion element of the present invention and the solar battery of the present invention is provided with a conductive material such as a conductive material such as a metal plate or a non-conductive material such as a glass plate or a plastic film. A structure having a different structure can be used. Examples of materials used for the conductive support include metal (for example, platinum, gold, silver, copper, aluminum, rhodium, indium) or conductive metal oxide (for example, indium-tin composite oxide, tin oxide doped with fluorine) And carbon). The thickness of the conductive support is not particularly limited, but is preferably 0.3 mm to 5 mm.

  The conductive support is preferably substantially transparent, and substantially transparent means that the light transmittance is 10% or more, more preferably 50% or more, and 80 % Or more is most preferable. In order to obtain a transparent conductive support, it is preferable to provide a conductive layer made of a conductive metal oxide on the surface of a glass plate or a plastic film. When the transparent conductive support 1 is used, light is preferably incident from the support side.

The conductive support preferably has a surface resistance of 50 Ω / cm ² or less, and more preferably 10 Ω / cm ² or less.

《Charge transfer layer》
The charge transfer layer used in the present invention will be described.

A redox electrolyte is preferably used for the charge transfer layer. Here, examples of the redox electrolyte include I ⁻ / I ₃ ⁻ system, Br ⁻ / Br ₃ ⁻ system, and quinone / hydroquinone system. Such a redox electrolyte can be obtained by a conventionally known method. For example, an I ⁻ / I ₃ ⁻ based electrolyte can be obtained by mixing iodine ammonium salt and iodine. The charge transfer layer is composed of dispersions of these redox electrolytes. These dispersions are liquid electrolytes when they are in solution, and are dispersed in solid polymer electrolytes and gel substances when dispersed in polymers that are solid at room temperature. When called, it is called a gel electrolyte. When a liquid electrolyte is used as the charge transfer layer, an electrochemically inert solvent is used as the solvent, for example, acetonitrile, propylene carbonate, ethylene carbonate, or the like is used. Examples of the solid polymer electrolyte include the electrolyte described in JP-A No. 2001-160427, and examples of the gel electrolyte include the electrolyte described in “Surface Science” Vol. 21, No. 5, pages 288 to 293.

《Counter electrode》
The counter electrode used in the present invention will be described.

Counter electrode, as long as it has conductivity, but any conductive material is used, I ₃ ^- catalytic ability to perform fast enough the reduction reaction of oxidation and other redox ions such as ions It is preferable to use what you have. Examples of such a material include a platinum electrode, a surface of a conductive material subjected to platinum plating or platinum deposition, rhodium metal, ruthenium metal, ruthenium oxide, and carbon.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

Example 1
<< Production of Photoelectric Conversion Element 101 >>
A photoelectric conversion device as shown in FIG. 1 was produced as described below.

  62.5 ml of titanium tetraisopropoxide (first grade, manufactured by Wako Pure Chemical Industries, Ltd.) was dropped into 375 ml of pure water at room temperature with vigorous stirring for 10 minutes (a white precipitate was formed), and then 70% aqueous nitric acid was added. After 2.65 ml was added and the reaction system was heated to 80 ° C., stirring was continued for 8 hours. Furthermore, after concentrating under reduced pressure until the volume of the reaction mixture becomes about 200 ml, 125 ml of pure water and 140 g of titanium oxide powder (Super Titania F-6 manufactured by Showa Titanium Co., Ltd.) are added to a titanium oxide suspension (about 800 ml ) Was prepared. The titanium oxide suspension is applied onto a transparent conductive glass plate coated with fluorine-doped tin oxide, dried naturally and then fired at 300 ° C. for 60 minutes to form a film-like titanium oxide on the support. did.

  Next, a solution in which 5 g of Exemplified Compound I-1 was dissolved in 200 ml of methanol solution was prepared, the above-mentioned film-like titanium oxide (semiconductor layer for photoelectric conversion material) was immersed together with 1 g of trifluoroacetic acid, and 2 Ultrasonic irradiation for hours. After the reaction, the film-like titanium oxide (semiconductor layer for photoelectric conversion material) was washed with chloroform and vacuum dried to prepare a photosensitive layer 2 (semiconductor for photoelectric conversion material).

  As the counter electrode 4, a transparent conductive glass plate coated with fluorine-doped tin oxide and further carrying platinum thereon is used, and the volume ratio is 1 between the conductive support 1 and the counter electrode 4. : A redox electrolyte in which tetrapropylammonium iodide and iodine were dissolved in a mixed solvent of acetonitrile / ethylene carbonate of 4 to a concentration of 0.46 mol / liter and 0.06 mol / liter, respectively. The charge transfer layer 3 was produced, and the photoelectric conversion element 101 was produced.

<< Production of Photoelectric Conversion Elements 102 to 130 >>: Present Invention In the production of the photoelectric conversion element 101, photoelectric conversion elements 102 to 130 were similarly performed except that Exemplified Compound I-1 was changed to each compound shown in Table 1. Got.

<< Preparation of Photoelectric Conversion Elements R1 and R2 >>: Comparative Example Photoelectric conversion element R1 was prepared in the same manner as in the preparation of photoelectric conversion element 101 except that Exemplified Compound I-1 was changed to Comparative Compounds R1 and R2 shown in Table 1. And R2.

<< Fabrication of Solar Cells SC-101 to SC-130 >>: After the side surface of the photoelectric conversion element 101 of the present invention is encapsulated with resin, lead wires are attached to each of the solar cells SC-101 to SC-130 of the present invention. Lots were made one by one.

<< Production of Solar Cells SC-R1 and R2 >>: Comparative Example In the production of the above-described solar cell SC-1, solar cells SC-R1 and R2 were similarly manufactured except that comparative photoelectric conversion elements R1 and R2 were used. Three lots were prepared.

<< Evaluation of photoelectric conversion characteristics of solar cells >>
Solar cells SC-101 to SC-130 obtained above and solar cells SC-R1 and R2 are each 100 mW / m by solar simulator (manufactured by JASCO (JASCO), low energy spectral sensitivity measuring device CEP-25). The short-circuit current density Jsc (mA / cm ² ) and the open-circuit voltage value Voc (V) when irradiated with light having an intensity of ² were measured and shown in Table 1. The indicated value was the average value of the measurement results for three solar cells having the same configuration and production method.

From Table 1, compared with comparison, the solar cell of this invention shows a high photoelectric conversion characteristic, and any one compound represented by the said General formula (1), (2) and (3)-(6) It turns out that it is effective to use. In addition, the solar cells SC-101 to SC-130 of the present invention are excellent in stability because no decrease in photoelectric conversion efficiency is observed even after 100 hours of light irradiation of 100 mW / m ² by a solar simulator. Became clear.

It is a fragmentary sectional view which shows an example of the structure of the photoelectric conversion element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Photosensitive layer 3 Charge transfer layer 4 Counter electrode

Claims (9)

The semiconductor for photoelectric conversion materials characterized by including the pigment | dye represented by General formula (1).

(In the formula, A represents an aryl group or a heterocyclic group which may have a substituent, R ₁ and R ₂ represent a hydrogen atom or a substituent, and may combine with each other to form a cyclic structure; M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, R represents an alkyl or aryl group, and n represents 0 to 4 Is an integer.) The semiconductor for photoelectric conversion materials characterized by including the pigment | dye represented by General formula (2).

(In the formula, A represents a heterocyclic group which may have a substituent, R _{1 to} R ₃ represent a hydrogen atom or a substituent, and R _{1 to} R ₃ bonded to each other to form a cyclic structure. M represents a hydrogen atom or a salt-forming cation, Y represents —O— or —NR′—, R ′ represents a hydrogen atom or a substituent, R represents an alkyl or aryl group, and n represents It is an integer from 1 to 4.) The semiconductor for a photoelectric conversion material according to claim 1, wherein A in the general formula (1) is represented by the following general formula (3).

(Wherein, R ₄ and R ₅ are a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, may form a ring bonded to R ₆ or R _7, R ₄ and R ₅ are bonded to each other A heterocycle may be formed, and R _{6 to} R ₉ each represent a hydrogen atom or a substituent, and any two adjacent groups may be bonded to each other to form a ring, where * represents a bonding position. .) The semiconductor for a photoelectric conversion material according to claim 1, wherein A in the general formula (1) is represented by the following general formula (4).

(In the formula, R ₁₀ and R ₁₁ each represent a hydrogen atom or a substituent, and may be bonded to each other to form a ring; m represents 0 to 4; Z represents an oxygen atom, a sulfur atom or NR ₁₂ ; R ₁₂ represents a hydrogen atom or a substituent, where * represents a bonding position. The semiconductor for a photoelectric conversion material according to claim 2, wherein A in the general formula (2) is represented by the following general formula (5).

(In the formula, R ₁₃ represents a hydrogen atom or a substituent, R ₁₄ or R ₁₅ represents a hydrogen atom or a substituent, and each may be bonded to form a ring, and X represents an oxygen atom, a sulfur atom, or selenium. Represents an atom, NR ₁₆ or C (R ₁₇ ) R ₁₈ , R _{16 to} R ₁₈ represent a hydrogen atom or a substituent, and * represents a bonding position. The semiconductor for a photoelectric conversion material according to claim 2, wherein A in the general formula (2) is represented by the following general formula (6).

(In the formula, R ₁₉ represents a hydrogen atom or an alkyl, aryl or heterocyclic group, R ₂₀ represents a hydrogen atom or a substituent, and each may be bonded to form a ring; p represents 0 to 4; Q represents 0 to 2. Note that * represents a bonding position.) It is a metal oxide or a metal sulfide semiconductor, The semiconductor for photoelectric conversion materials of any one of Claims 1-6 characterized by the above-mentioned. The photoelectric conversion element characterized by the layer containing the semiconductor for photoelectric conversion materials of any one of Claims 1-7 being provided on the electroconductive support body. A solar cell comprising the photoelectric conversion element according to claim 8, a charge transfer layer, and a counter electrode.

Images