JP2005209682A - Semiconductor for photoelectric conversion material, optoelectric transducer and solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor for a photoelectric conversion material displaying high photoelectric-conversion efficiency and excellent stability, an optoelectric transducer and a solar cell. <P>SOLUTION: The semiconductor for the photoelectric conversion material containing a compound shown by a general formula (1), the optoelectric transducer using the semiconductor for the photoelectric conversion material and the solar cell are provided. <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 the 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 a solar cell 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 (for example, see Non-Patent Document 1).

  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, Non-patent document 2).

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. Technological developments using reported materials such as ZnO, TiO ₂ , zirconium oxide (ZrO ₂ ), niobium oxide (Nb ₂ O ₅ ) and the like have been carried out.

In addition, since dye-sensitized wet solar cells are much cheaper to manufacture than silicon solar cells, there is a possibility of replacing silicon solar cells used in the above-mentioned various products in the future. In some cases, the characteristics of the solar cell according to each product are important. Various characteristics of solar cells are shown below.
1. 1. Short circuit current 2. Open circuit 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 (see, for example, Patent Documents 3, 4, and 5) have been studied so far, and merocyanine dyes, xanthene dyes, coumarin dyes, acridine dyes, phenylmethane dyes, and the like. Is well known. Other new pigment nuclei have also been developed. (For example, refer to Patent Document 6).

On the other hand, methine dyes have been disclosed (for example, see Patent Document 7), but the absorption wavelength region is still short, and the conversion efficiency tends not to improve even if the methine portion is simply extended and lengthened. These photoelectric conversion efficiencies are not yet sufficient. Therefore, further development of a dye having strong adsorption power and high efficiency up to a long wavelength region is desired.
Japanese Patent Laid-Open No. 1-220380 Japanese National Patent Publication No. 5-504023 JP-A-11-167937 (Claims) JP-A-11-214730 (Claims) JP-A-11-214731 (Claims) JP 2001-76775 A (Claims) JP 2003-264010 A Nature, 261 (1976) p402. J. et al. Am. Chem. Soc. 115 (1993) 6382

  The objective of this invention is providing the semiconductor for photoelectric conversion materials, a photoelectric conversion element, and a solar cell which show high photoelectric conversion efficiency and the outstanding stability.

  The above object of the present invention can be achieved by the following configuration.

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

[Wherein, R and R ₁ each represent a substituent, R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a substituent, and R _{2 to} R ₄ are bonded to each other to form 5-6 A member ring may be formed, X ₁ represents an oxygen atom or a sulfur atom, A ₂ represents a group of atoms necessary to form a _3- to 9-membered ring with a carbon atom, and A ₃ represents a heterocyclic ring. , N represents 0 to 2, p represents 0 to 12, and q represents 0 to 2. ]
(Claim 2)
The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (2).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represents a group having the same meaning as in general formula (1), R ₅ represents an alkyl group, an aryl group or a heterocyclic group, X ₂ represents an oxygen atom or a sulfur atom, A ₃ represents a heterocyclic ring, L represents a divalent linking group, m represents 0 or 1, and n, p, and q have the same meanings as in the general formula (1). Represents the number of ]
(Claim 3)
The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (3).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) X ₃ , X ₄ and X ₅ each represents an oxygen atom or a sulfur atom, m represents a number having the same meaning as in the general formula (2), and n, p and q represent the general formula (1) and Represents a synonymous number. ]
(Claim 4)
The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (4).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) R ₆ represents an alkyl group, an aryl group or a heterocyclic group, Y ₁ represents —N═ or —CR ₇ ═, R ₇ represents an alkyl group, an aryl group or a heterocyclic group, m represents a number synonymous with general formula (2), and n, p, and q represent a number synonymous with general formula (1). ]
(Claim 5)
The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (5).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) R ₈ represents a substituent, Y ₂ and Y ₃ each independently represent —N═ or —CR ₉ ═, and at least one of R ₈ or R ₉ represents — (L) _m. -COOH is represented, m represents the number synonymous with General formula (2), n, p, q represents the number synonymous with General formula (1). ]
(Claim 6)
The photoelectric conversion material for semiconductor according to claim 1, wherein X ₁ is an oxygen atom.

(Claim 7)
X ₁ is an oxygen atom, a photoelectric conversion material for semiconductor according to any one of claims 2-5, wherein X ₂ is a sulfur atom.

(Claim 8)
The semiconductor for a photoelectric conversion material according to claim 3, wherein X ₁ and X ₃ are oxygen atoms, and X ₂ , X ₄ and X ₅ are sulfur atoms.

(Claim 9)
N in general formula (1)-(5) is 0, The semiconductor for photoelectric conversion materials of any one of Claims 1-8 characterized by the above-mentioned.

(Claim 10)
The said semiconductor for photoelectric conversion materials is a metal oxide semiconductor or a metal sulfide semiconductor, The semiconductor for photoelectric conversion materials of any one of Claims 1-9 characterized by the above-mentioned.

(Claim 11)
The photoelectric conversion element of any one of Claims 1-10 is provided on the electroconductive support body.

(Claim 12)
A solar cell comprising the photoelectric conversion element according to claim 11, 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.

  The present invention will be described in more detail.

  As a result of intensive studies to solve the above problems, the present inventors have found specific structures as represented by the general formulas (1) to (5) described in claims 1 to 12, respectively. The semiconductor for photoelectric conversion materials which sensitized using the compound which has it succeeded in obtaining the semiconductor for photoelectric conversion materials which shows the effect as described in this invention, ie, the high photoelectric conversion efficiency, and the outstanding stability.

<< 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 TiO ₂ or Nb ₂ O ₅ is more preferably used, and TiO ₂ is preferably used among them.

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.

  High photoelectric conversion which is one of the objects described in the present invention by sensitizing the semiconductor for photoelectric conversion material with any one of the compounds represented by the general formulas (1) to (5). The semiconductor for photoelectric conversion materials of the present invention showing efficiency and excellent stability can be obtained.

<< Compound Represented by Formula (1) >>
In the general formula (1), the substitution represented by R, R ₁ , R ₂ , R ₃ and R ₄ is not particularly limited as long as it can be substituted. For example, an alkyl group (for example, a methyl group, an ethyl group) , A propyl group, an isopropyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, etc., which may have a substituent, such as a trifluoromethyl group) A cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), a bicycloalkyl group (eg, bicyclo [1,2,2] heptan-2-yl group, bicyclo [2,2,2] octane-3-yl group) Etc.), an alkenyl group (eg, vinyl group, allyl group, prenyl group, octenyl group, etc.), cycloalkenyl group (eg, 2-cyclopentene- 1-yl group, 2-cyclohexen-1-yl group, etc.), bicycloalkenyl group (for example, bicyclo [2,2,1] hept-2-en-1-yl group, bicyclo [2,2,2] octet) -2-en-4-yl group, etc.), alkynyl groups (for example, propargyl group, ethynyl group, trimethylsilylethynyl group, etc.), aryl groups (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-phenyltetrazole- -Oxy group, 2-tetrahydropyranyloxy group, pyridyloxy group, thiazolyloxy group, oxazolyloxy group, imidazolyloxy group, etc.), halogen atom (for example, chlorine atom, bromine atom, iodine atom, fluorine atom), Alkoxy groups (for example, methoxy, ethoxy, propyloxy, tert-butoxy, pentyloxy, hexyloxy, octyloxy, dodecyloxy, etc.), cycloalkoxy groups (for example, cyclopentyloxy, cyclohexyloxy) Group), aryloxy group (for example, phenoxy group, naphthyloxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group), alkylthio group (For example, methylthio group Ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), complex Ring thio group (for example, pyridylthio group, thiazolylthio group, oxazolylthio group, imidazolylthio group, furylthio group, pyrrolylthio group, etc.), alkoxycarbonyl group (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxy) Carbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminos) Sulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl 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.) An acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2- Tilhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenyl) Carbonyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), acylamino group (for example, acetylamino group, benzoylamino group, formylamino group, pivaloylamino group) , Lauroylamino group, 3,4,5-tri-n-octyloxyphenylcarbonylamino group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbo Ruamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc. ), Carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylamino) Carbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), alkyl Sulfinyl group or arylsulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl 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, cyclopentyl) Mino 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-butyldimethylsilyl) Oxy group, etc.), 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.), aryloxycal Nyloxy groups (for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group, etc.), alkoxycarbonylamino groups (for example, methoxycarbonylamino group, ethoxycarbonylamino group, tert -Butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group, etc.), aryloxycarbonylamino group (for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn- Octyloxyphenoxycarbonylamino group, etc.), sulfamoylamino groups (for example, sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfo group) Nylamino group, etc.), mercapto group, arylazo group (eg, phenylazo group, naphthylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), heterocyclic azo group (eg, , Pyridylazo group, thiazolylazo group, oxazolylazo 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, diphenylphosphino group, methylphenoxyphosphino group, etc.), phosphinyl group (eg phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group etc.), phosphinyloxy group (eg , Diphenoxyphosphinyloxy group, diocty Oxyphosphinyloxy group, etc.), phosphinylamino group (eg, dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, etc.), silyl group (eg, trimethylsilyl group, tert-butyldimethylsilyl group, phenyl) Dimethylsilyl group, etc.), cyano group, nitro group, hydroxyl group, sulfo group, carboxyl group and the like. In addition, they may be substituted with another substituent.

In the general formula (1), when n is 1 or more, R _{2 to} R ₄ may be different from each other, may be bonded to each other to form a cyclic structure, and may be substituted by the above-described substituents. Further, it may be condensed with another ring structure. When n is 1 or more, R ₂ and R ₃ which are repeating units may be different from each other, and a ring may be formed between R ₂ or R ₃ of adjacent repeating units. Preferred examples of the formed ring or polycyclic aromatic, heterocyclic or aliphatic ring include, for example, cyclobutene ring, cyclopentene ring, cyclohexene ring, benzene ring, pyridine ring, dihydropyridine ring, tetrahydropyridine ring, furan A ring, a thiophene ring, and a dihydrothiophene ring.

In the general formula (1), A ₂ represents an atomic group necessary to form a 3 to 9 membered ring with the carbon atoms. Examples of the ring formed by A ₂ and a carbon atom include thiazolidine-4-one ring, thiazolidine-4-thione ring, oxazolidin-4-one ring, oxazolidine-4-thione ring, isoxazolin-3-one ring, And isoxazoline-3-thione ring.
In the general formula (1), A ₃ represents a heterocyclic ring. Examples of the heterocyclic ring represented by A ₃ include pyrazolone ring, pyrazolotrizole ring, pyrazoloimidazole ring, pyrrolidone ring, pyridine-2,6-dione ring, isoxazolone ring, dihydroquinoline ring, pyrazolidine Examples include a dione ring, a pyrrole-2,4-dione ring, and an isoquinoline-1,3-dione ring.

  R is preferably a hydrogen atom, a halogen atom, an alkyl group, a hydroxyl group, an alkoxy group, an amino group, an acylamino group, or the like, and more preferably a hydrogen atom, an alkyl group, a hydroxyl group, or an acylamino group.

R ₁ is preferably a hydrogen atom (when p is 0), a halogen atom, an alkyl group, an aryl group, an alkoxy group, an amino group, an acyloxy group, etc., preferably a hydrogen atom (when p is 0), an alkyl Group, an alkoxy group.

R _{2 to} R ₄ are preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amino group or the like, more preferably a hydrogen atom or an alkyl group, and R ₂ and R ₃ , or n is 1 or more. In some cases, any R ₂ , R ₃ or R ₄ may be bonded to each other to form a 5- or 6-membered cyclic structure (for example, a thiophene ring, a furan ring, a cyclohexene ring, or a pyran ring).

Preferred as the ring represented by A ₂ are a thiazolidine-4-one ring and a thiazolidine-4-thione ring, and most preferred is a thiazolidine-4-one ring.

Preferred as the heterocyclic ring represented by A ₃ are a thiazolidine-4-one ring, a pyrazolone ring, a pyrazolotrizole ring, a pyrazoloimidazole ring, and a pyrrolidone ring.

X ₁ is preferably an oxygen atom.

<< Compound Represented by Formula (2) >>
In the general formula _{(2), R, R 1} ~R 4, X 1, p, q, n and A _3, the R in the general formula _{(1), R 1 ~R 4} , X 1, p, q, a preferred range has the same meaning as n, and a ₃ is similar.

In the general formula (2), X ₂ represents an oxygen atom or a sulfur atom, preferably a sulfur atom.

In the general formula (2), R ₅ represents an alkyl group, an aryl group or a heterocyclic group, preferably an alkyl group or an aryl group.

  In the general formula (2), L represents a divalent linking group, and specific examples of the divalent linking group include a methylene group, an ethylene group, an ethyne group, an octane-1,8-diyl group, and cyclohexane-1. , 4-diyl group, p-phenylene group, o-phenylene group, naphthalene-1,4-diyl group, naphthalene-1,8-diyl group, thiophene-2,5-diyl group, etc. are particularly preferable. A methylene group, an ethyne group, a p-phenylene group, and an o-phenylene group. Further, these linking groups may be further substituted with the above-described substituents.

  In the general formula (2), m represents 0 or 1.

<< Compound Represented by Formula (3) >>
In the general formula (3), R, R _{1 to} R ₅ , X ₁ , X ₂ , p, q, L, n and m are R, R _{1 to} R ₅ , X ₁ , _{X 2, p, q, L} , have the same meanings as n and m preferably ranges are also the same.

In the general formula (3), X ₃ , X ₄ and X ₅ each represent an oxygen atom or a sulfur atom, preferably X ₃ is an oxygen atom, and X ₄ and X ₅ are sulfur atoms.

<< Compound Represented by Formula (4) >>
In the general formula (4), R, R _{1 to} R ₅ , X ₁ , X ₂ , p, q, L, n, and m are R, R _{1 to} R ₅ , X ₁ , _{X 2, p, q, L} , have the same meanings as n and m preferably ranges are also the same.

In the general formula (4), R ₆ represents an alkyl group, an aryl group, or a heterocyclic group.

In the general formula (4), Y ₁ represents -N = or -CR ₇ =, preferably -N =.

In the general formula (4), R ₇ represents an alkyl group, an aryl group, or a heterocyclic group.

<< Compound Represented by Formula (5) >>
In the general formula (5), R, R _{1 to} R ₅ , X ₁ , X ₂ , p, q, L, n, and m are R, R _{1 to} R ₅ , X ₁ , _{X 2, p, q, L} , have the same meanings as n and m preferably ranges are also the same.

In the general formula (5), R ₈ represents a substituent and has the same meaning as R in the general formula (1), but preferably an alkyl group, an aryl group, an alkenyl group, an alkoxy group, a carboxyl group, an amino group, a cyano group. And an alkoxycarbonyl group, and an alkyl group, an aryl group, an alkenyl group, a carboxyl group, and an alkoxycarbonyl group are more preferable.

In General Formula (5), Y ₂ and Y ₃ each independently represent —N═ or —CR ₉ ═. More specifically, the compound represented by General Formula (5) is represented by Y ₂ and Y ₃ . Depending on the difference, it is possible to take partial structures of four types of condensed rings represented by the following general formulas (5-1) to (5-4) (in this case, they are combined with a methine group at *). In these structures, the substituents of R ₈ and R are as defined above, and R ₉ may be independently the same or different substituents.

Y ₂ and Y ₃ are preferably Y ₃ ═C (R ₉ ) —, and R ₉ is preferably a substituted or unsubstituted alkyl group, aryl group, heterocyclic group, amino group, acylamino group, alkoxy Group, alkenyl group, alkoxycarbonyl group, carboxyl group and the like, more preferably substituted or unsubstituted alkyl group, aryl group, heterocyclic group, alkenyl group and carboxyl group. Y ₂ and Y ₃ are more preferably Y ₃ = C (R ₉ )-and Y ₂ = N-.

  Specific examples of the compounds represented by the general formulas (1) to (5) according to the present invention are shown below, but the present invention is not limited thereto.

  The compounds represented by the general formulas (1) to (5) according to the present invention are described in, for example, JP-A-10-60296, JP-A-2000-191934, JP-A-2003-203684, and the like. It can be synthesized with reference to the conventionally known methods.

  Although an example of a synthetic method is specifically shown below, other compounds can be synthesized in the same manner, and the synthetic method is not limited thereto.

<< Synthesis Example 1 >>
<< Synthesis of Exemplified Compound I-2 >>
1) Synthesis route

2) Synthesis of Intermediate 3 Intermediate 1: 4.95 g, Intermediate 2: 3.22 g, Toluene: 40 ml and morpholine: 1.95 g are added, and a reflux reaction is carried out for 2 hours while removing the water produced. Thereafter, the mixture was cooled and recrystallized with stirring, and after filtration, it was washed with toluene and then ethyl acetate in this order to obtain 6.13 g of Intermediate 3: It was identified by Mass, 1H-NMR, and IR spectrum, and confirmed to be the target product.

3) Synthesis of Exemplary Compound I-2 Intermediate 3: 6.00 g, dimethyl sulfate: 21.1 mg, and toluene: 80 ml were added, and the mixture was heated and stirred at 90 to 95 ° C. for 2 hours. Then, after cooling, when ethyl acetate was added, since it was oiled out, it was decanted and the supernatant was removed. Next, Intermediate 4: 3.52 g and 80 ml of pyridine were added to the remaining viscous oil, and the mixture was heated and stirred at 80 ° C. for 1 hour. Then, after cooling, diisopropyl ether was added, and crystals were precipitated and collected by filtration. The crystals were purified by silica gel column chromatography (developing solvent: n-hexane: ethyl acetate = 1: 1) to obtain 5.92 g of the target compound, exemplified compound I-2. It was identified by Mass, 1H-NMR, and IR spectrum, and confirmed to be the target product.

<< Synthesis Example 2 >>
<< Synthesis of Exemplified Compound I-22 >>
1) Synthesis route

2) Synthesis of Intermediate 6 Intermediate 2: 3.22 g, dimethyl sulfate 25.2 g, and toluene: 80 ml were added, and the mixture was heated and stirred at 90 to 95 ° C for 2 hours. Then, after cooling, ethyl acetate was added, and the precipitated crystals were collected by filtration. Next, crystals collected by filtration and intermediate 5: 4.50 g and pyridine: 100 ml were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. Then, after cooling, diisopropyl ether was added, and crystals were precipitated and collected by filtration. The crystals were purified by silica gel column chromatography (developing solvent: n-hexane: ethyl acetate = 1: 2) to obtain 5.02 g of the target product, Intermediate 6: 5.02. It was identified by Mass, 1H-NMR, and IR spectrum, and confirmed to be the target product.

3) Synthesis of Exemplified Compound I-22 Intermediate 6: 3.31 g, Intermediate 1: 2.47 g, Toluene: 50 ml and Morpholine: 0.97 g were added, and the reflux reaction was carried out for 3 hours while removing the generated water. Do. Thereafter, the mixture was cooled with stirring, recrystallized, collected by filtration, and then washed in the order of toluene and then ethyl acetate to obtain 4.33 g of Exemplified Compound I-22. It was identified by Mass, 1H-NMR, and IR spectrum, and confirmed to be the target product.

<< Sensitivity treatment of semiconductor for photoelectric conversion material >>
The semiconductor for photoelectric conversion materials of the present invention is sensitized by including any one compound represented by the general formulas (1) to (5), and can exhibit the effects described in the present invention. Become. 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.

The total content of each compound represented by the general formulas (1) to (5) per 1 m ² of the semiconductor layer (which may be a semiconductor) is preferably in the range of 0.01 mmol to 100 mmol, and more preferably. Is from 0.1 to 50 mmol, particularly preferably from 0.5 to 20 mmol.

  When performing sensitization using any one of the compounds represented by the general formulas (1) to (5) according to the present invention, the compounds may be used alone or in combination. Any one of the compounds represented by the general formulas (1) to (5) according to the present invention and other compounds (for example, U.S. Pat. Nos. 4,684,537, 4,927, No. 721, No. 5,084,365, No. 5,350,644, No. 5,463,057, No. 5,525,440, etc. The compounds described in each specification, JP-A-7-249790, JP-A-2000-150007, and the like 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 to include any one compound represented by the general formulas (1) to (5) in the semiconductor, the compound was dissolved in an appropriate solvent (such as ethanol) and dried well in the solution. A method of immersing a semiconductor for a long time is common.

  When producing a semiconductor for a photoelectric conversion material using a combination of any one of the compounds represented by the general formulas (1) to (5) or another sensitizing dye compound, A mixed solution of these compounds may be prepared and used. Alternatively, a solution may be prepared for each compound and 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, a sensitization process is performed by making a semiconductor contain any one compound represented by the said General formula (1)-(5). However, the 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 them, pyridine, 4-t-butylpyridine, and polyvinylpyridine are preferable. 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. .

  In addition, as a dye that can be used in combination with any one of the compounds represented by the general formulas (1) to (5) according to the present invention, those that can spectrally sensitize the semiconductor according to the present invention. Any dye can be used. In order to make the wavelength range of photoelectric conversion as wide 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.

  Among the dyes according to the present invention, metal complex dyes, phthalocyanine dyes, porphyrin dyes, and polymethine dyes are preferably used from the comprehensive viewpoints such as photoelectron transfer reaction activity, light durability, and photochemical stability.

  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. From the above, the semiconductor fine particle aggregate film is preferably fired to increase the mechanical strength and to obtain 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 beforehand to remove bubbles in the film, and the general formulas (1) to (5) It is preferable that any one of the above compounds can enter deep inside the semiconductor layer (semiconductor film), and it is particularly preferable when the semiconductor layer (semiconductor film) is a porous structure film.

"solvent"
The solvent used for dissolving any one compound of the general formulas (1) to (5) can dissolve the compound, and can dissolve the semiconductor or react with the semiconductor. There is no particular limitation if it is not present, but in order to prevent moisture and gas dissolved in the solvent from entering the semiconductor film and hindering the sensitization treatment such as adsorption of the compound, degassing and distillation in advance. It is preferable to purify it.

  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 on which the semiconductor has been baked in the solution containing any one compound of the general formulas (1) to (5) is such that the compound enters the semiconductor layer (semiconductor film) deeply and adsorbs it. From the viewpoint of sufficiently proceeding, sufficiently sensitizing the semiconductor, and suppressing degradation of the compound, which is generated by decomposition of the compound in a solution and hinders adsorption of the compound, at 25 ° C., It is preferably 3 hours to 48 hours, more preferably 4 hours to 24 hours. 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.

  When immersed, the solution containing any one compound of the general formulas (1) to (5) may be used by heating to a temperature at which it does not boil as long as the compound does not decompose. 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. It is manufactured through a process of adsorbing any one compound represented by (5).

  In addition, 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, and the semiconductor is formed from any one compound represented by the general formulas (1) to (5). 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 into the substrate. 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 above general formulas (1) to (5) to sensitize the semiconductor film, thereby photosensitive layer 2. Form. 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 decompressed or heat-treated to remove bubbles in the film, and any one compound represented by the general formulas (1) to (5) is converted into a semiconductor film. It is preferable to be able to enter deep inside.

  When any one of the compounds represented by the general formulas (1) to (5) is adsorbed to the semiconductor according to the present invention, it may be used alone or 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.

  In particular, when the application of the semiconductor is a solar cell, it is preferable to use a mixture of two or more types of dyes so that the wavelength range of photoelectric conversion can be widened and sunlight can be used as effectively as possible.

  The semiconductor for photoelectric conversion materials sensitized by combining a plurality of types of any one of the compounds represented by the general formulas (1) to (5) described above is a solution prepared by mixing the compounds to be used together It may be prepared by immersing in a solution, or a solution may be prepared for each compound, and it may be prepared by immersing in each solution in turn.

  When preparing a separate solution for each compound and immersing in each solution in order, the effect of the present invention regardless of the order in which the compound or a conventionally known sensitizing dye is adsorbed to the semiconductor Can be obtained.

  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⁻ , Br ⁻ / Br ^{3 −} , and quinone / hydroquinone. Such a redox electrolyte can be obtained by a conventionally known method. For example, an I ⁻ / I ³⁻ type electrolyte can be obtained by mixing an ammonium salt of iodine 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.

The counter electrode is not particularly limited as long as it has conductivity, and any conductive material can be used. However, the counter electrode has a catalytic ability to oxidize I ³⁻ ions and other redox ions at a sufficiently high rate. 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 1 >>
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-2 was dissolved in 200 ml of ethanol solution was prepared. 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 1 was produced.

<< Preparation of Photoelectric Conversion Elements 2 to 25 >>: Present Invention In the preparation of photoelectric conversion element 1, except that Exemplified Compound I-2 was changed to the compounds shown in Table 1, Photoelectric Conversion Elements 2 to 25 were obtained. It was.

<< Preparation of Photoelectric Conversion Elements R1 and R2 >> Comparative Example Photoelectric conversion elements R1 and R2 were obtained in the same manner as in the preparation of the photoelectric conversion element 1, except that the comparison compounds R1 and R2 shown in Table 1 were changed.

<< Preparation of Solar Cells SC-1 to SC-25 >>: The present invention photoelectric conversion element 1 was sealed with a resin, and then a lead wire was attached to each of the solar cells SC-1 to SC-25 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 >>
The solar cells SC-1 to SC-25 obtained above and the solar cells SC-R1 and R2 are each 100 mW / m by a 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 SC-R1 and R2 which are comparisons, the solar cell of the present invention exhibits high photoelectric conversion characteristics, and any one compound represented by the general formulas (1) to (5) is used. It turns out that it is effective to use. Moreover, the solar cells SC-1 to SC-25 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 (12)

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

[Wherein, R and R ₁ each represent a substituent, R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a substituent, and R _{2 to} R ₄ are bonded to each other to form 5-6 A member ring may be formed, X ₁ represents an oxygen atom or a sulfur atom, A ₂ represents a group of atoms necessary to form a _3- to 9-membered ring with a carbon atom, and A ₃ represents a heterocyclic ring. , N represents 0 to 2, p represents 0 to 12, and q represents 0 to 2. ] The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (2).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represents a group having the same meaning as in general formula (1), R ₅ represents an alkyl group, an aryl group or a heterocyclic group, X ₂ represents an oxygen atom or a sulfur atom, A ₃ represents a heterocyclic ring, L represents a divalent linking group, m represents 0 or 1, and n, p, and q have the same meanings as in the general formula (1). Represents the number of ] The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (3).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) X ₃ , X ₄ and X ₅ each represents an oxygen atom or a sulfur atom, m represents a number having the same meaning as in the general formula (2), and n, p and q represent the general formula (1) and Represents a synonymous number. ] The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (4).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) R ₆ represents an alkyl group, an aryl group or a heterocyclic group, Y ₁ represents —N═ or —CR ₇ ═, R ₇ represents an alkyl group, an aryl group or a heterocyclic group, m represents a number synonymous with general formula (2), and n, p, and q represent a number synonymous with general formula (1). ] The semiconductor for photoelectric conversion materials characterized by including the polymethine pigment | dye represented by following General formula (5).

[Wherein, R, R ₁ , R ₂ , R ₃ , R ₄ , X ₁ each represent a group having the same meaning as in general formula (1), and R ₅ , X ₂ , and L each represent general formula (2) R ₈ represents a substituent, Y ₂ and Y ₃ each independently represent —N═ or —CR ₉ ═, and at least one of R ₈ or R ₉ represents — (L) _m. -COOH is represented, m represents the number synonymous with General formula (2), n, p, q represents the number synonymous with General formula (1). ] The photoelectric conversion material for semiconductor according to claim 1, wherein X ₁ is an oxygen atom. X ₁ is an oxygen atom, a photoelectric conversion material for semiconductor according to any one of claims 2-5, wherein X ₂ is a sulfur atom. The semiconductor for a photoelectric conversion material according to claim 3, wherein X ₁ and X ₃ are oxygen atoms, and X ₂ , X ₄ and X ₅ are sulfur atoms. N in general formula (1)-(5) is 0, The semiconductor for photoelectric conversion materials of any one of Claims 1-8 characterized by the above-mentioned. The said semiconductor for photoelectric conversion materials is a metal oxide semiconductor or a metal sulfide semiconductor, The semiconductor for photoelectric conversion materials of any one of Claims 1-9 characterized by the above-mentioned. The photoelectric conversion element of any one of Claims 1-10 is provided on the electroconductive support body. A solar cell comprising the photoelectric conversion element according to claim 11, a charge transfer layer, and a counter electrode.

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