JP4821015B2 - Semiconductor for photoelectric conversion material, photoelectric conversion element and solar cell - Google Patents

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 (see, for example, Non-Patent Document 1).

  Thereafter, the dye is also improved. For example, Graetzel et al. Have adsorbed a ruthenium complex dye on a porous titanium oxide electrode, and currently obtain a solar cell having performance equivalent to that of a silicon solar cell. (For example, refer nonpatent literature 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 development using ZnO, TiO ₂ , zirconium oxide (ZrO ₂ ), niobium oxide (Nb ₂ O ₅ ), etc. as the reported substances has been continued.

  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 are known to have relatively excellent characteristics. However, since the dyes are expensive, they are cheaper and can be supplied stably. Dyes are more preferred. Many organic dyes have been studied so far because of such demands, but the photoelectric conversion efficiency is not yet sufficient, and no organic dyes having performance exceeding the ruthenium complex have been found. Currently.

  In addition, there are many reports on changes in the ligands of metal complex dyes, for example, metal complex dyes having xanthene dyes as ligands (for example, see Patent Document 3). In addition, metal complex dyes (for example, see Patent Document 4) immobilized on a semiconductor (for example, titanium oxide) with a boronic acid group have also been reported, but none of them have sufficient photoelectric conversion efficiency yet. is there.

None of these dyes yet have satisfactory performance as compared with the ruthenium complex, and therefore further development of dyes having strong adsorptive 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 2000-251957 A JP 2002-75475 A Nature, 261 (1976) p402. J. et al. Am. Chem. Soc. 115 (1993) 6382

  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.

（式中、Ｒ _１ 〜Ｒ _３ は水素原子又はアルキル基を表し、Ｒ _４ はアルキル基、フェニル基又はアミノ基を表し、Ｚ _１ は炭素原子および窒素原子と共に、ピリジル基、ピラジニル基、ピリミジニル基、ピリダジニル基、トリアジニル基、オキサゾリル基、チアゾリル基、ピラゾリル基、イミダゾリル基又はトリアゾリル基を形成するために必要な非金属原子団を表し、Ａｒはフェニル基、ナフチル基、チエニル基、フリル基又はチアゾリル基を表し、Ｍは水素原子又は塩形成性陽イオンを表し、ｎは０又は１を表す。）
２．一般式（３）又は（４）で表される化合物の少なくとも１種を配位子として有する金属錯体を含むことを特徴とする光電変換材料用半導体。

（式中、Ｒ _１ 〜Ｒ _３ は水素原子又はアルキル基を表し、Ｒ _４ はアルキル基、フェニル基、ピリジル基、チアゾリル基、ピラゾリル基又はアミノ基を表し、Ｚ _２ は炭素原子および窒素原子と共に、ピリジル基、ピラジニル基、ピリミジニル基、オキサゾリル基、チアゾリル基、ピラゾリル基又はイミダゾリル基を形成するために必要な非金属原子団を表し、Ａｒはフェニル基、チエニル基、フリル基又はチアゾリル基を表し、Ｍは水素原子又は塩形成性陽イオンを表し、ｎは０又は１を表す。）
３．一般式（５）〜（７）で表される化合物の少なくとも１種を配位子として有する金属錯体を含むことを特徴とする光電変換材料用半導体。

（式中、Ｒ _４ はアルキル基、フェニル基、ピリジル基、ピラゾリル基、チアゾリル基、ピラジニル基又はアミノ基を表し、Ｚ _１ 及びＺ _２ は炭素原子および窒素原子と共に、ピリジル基、ピラジニル基、オキサゾリル基、チアゾリル基、ピラゾリル基又はイミダゾリル基を形成するために必要な非金属原子団を表し、Ａｒはフェニル基、チエニル基、フリル基又はチアゾリル基を表し、Ｍは水素原子又は塩形成性陽イオンを表す。）
４．一般式（８）で表される化合物を配位子として有する金属錯体を含むことを特徴とする光電変換材料用半導体。

（式中、Ｒ _４ はアルキル基、フェニル基、ピリジル基、ピラゾリル基、チアゾリル基、ピラジニル基又はアミノ基を表し、Ａｒはフェニル基、チエニル基、フリル基又はチアゾリル基を表し、Ｍは水素原子又は塩形成性陽イオンを表す。）
５．前記金属錯体が、中心金属として、ルテニウムを有することを特徴とする前記１〜４のいずれか１項に記載の光電変換材料用半導体。
６．前記光電変換材料用半導体に係る半導体が、金属酸化物もしくは金属硫化物半導体であることを特徴とする前記１〜５のいずれか１項に記載の光電変換材料用半導体。
７．前記１〜６のいずれか１項に記載の光電変換材料用半導体を含有する層が導電性支持体上に設けられていることを特徴とする光電変換素子。
８．前記７に記載の光電変換素子が、電荷移動層及び対向電極を有することを特徴とする太陽電池。
なお、以下（１）〜（８）は参考とされる手段である。 The present invention has been achieved by the following means 1 to 8 .
1. A semiconductor for a photoelectric conversion material comprising a metal complex having at least one compound represented by the general formula (1) or (2) as a ligand.

(Wherein R _{1 to} R ₃ represent a hydrogen atom or an alkyl group, R ₄ represents an alkyl group, a phenyl group or an amino group, and Z ₁ together with a carbon atom and a nitrogen atom together with a pyridyl group, a pyrazinyl group and a pyrimidinyl group) Represents a nonmetallic atomic group necessary for forming a pyridazinyl group, triazinyl group, oxazolyl group, thiazolyl group, pyrazolyl group, imidazolyl group or triazolyl group, Ar represents a phenyl group, naphthyl group, thienyl group, furyl group or thiazolyl Represents a group, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.)
2. A semiconductor for a photoelectric conversion material, comprising a metal complex having at least one compound represented by formula (3) or (4) as a ligand.

(Wherein R _{1 to} R ₃ represent a hydrogen atom or an alkyl group, R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a thiazolyl group, a pyrazolyl group, or an amino group, and Z ₂ together with a carbon atom and a nitrogen atom) Represents a nonmetallic atomic group necessary for forming a pyridyl group, a pyrazinyl group, a pyrimidinyl group, an oxazolyl group, a thiazolyl group, a pyrazolyl group or an imidazolyl group, and Ar represents a phenyl group, a thienyl group, a furyl group or a thiazolyl group. , M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.)
3. The semiconductor for photoelectric conversion materials characterized by including the metal complex which has at least 1 sort (s) of the compound represented by General formula (5)-(7) as a ligand.

(Wherein R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a pyrazolyl group, a thiazolyl group, a pyrazinyl group or an amino group, and Z ₁ and Z ₂ together with a carbon atom and a nitrogen atom together with a pyridyl group, a pyrazinyl group and an oxazolyl group) Represents a nonmetallic atomic group necessary for forming a group, thiazolyl group, pyrazolyl group or imidazolyl group, Ar represents a phenyl group, thienyl group, furyl group or thiazolyl group, and M represents a hydrogen atom or a salt-forming cation Represents.)
4). The semiconductor for photoelectric conversion materials characterized by including the metal complex which has a compound represented by General formula (8) as a ligand.

(In the formula, R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a pyrazolyl group, a thiazolyl group, a pyrazinyl group or an amino group, Ar represents a phenyl group, a thienyl group, a furyl group or a thiazolyl group, and M represents a hydrogen atom. Or represents a salt-forming cation.)
5. 5. The semiconductor for a photoelectric conversion material according to any one of 1 to 4, wherein the metal complex has ruthenium as a central metal.
6). 6. The semiconductor for photoelectric conversion material according to any one of 1 to 5, wherein the semiconductor according to the semiconductor for photoelectric conversion material is a metal oxide or a metal sulfide semiconductor.
7). 7. A photoelectric conversion element, wherein a layer containing the semiconductor for a photoelectric conversion material according to any one of 1 to 6 is provided on a conductive support.
8). 8. The solar cell according to 7, wherein the photoelectric conversion element has a charge transfer layer and a counter electrode.
The following (1) to (8) are means to be referred to.

(1 )
A semiconductor for a photoelectric conversion material comprising a metal complex having a compound having absorption in a visible part as a ligand.

(2 )
A semiconductor for a photoelectric conversion material comprising a metal complex having at least one compound represented by the general formula (1) or (2) as a ligand.

(In the formula, R _{1 to} R ₃ represent a hydrogen atom or a substituent, R ₄ represents an alkyl group, an aryl group, a heterocyclic group, or an amino group, and Z ₁ forms a 5- or 6-membered aromatic heterocyclic ring. (N represents an aromatic carbocyclic group or an aromatic heterocyclic group, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1).
(3 )
A semiconductor for a photoelectric conversion material, comprising a metal complex having at least one compound represented by formula (3) or (4) as a ligand.

(Wherein R _{1 to} R ₃ represent a hydrogen atom or a substituent, R ₄ represents an alkyl group, an aryl group, a heterocyclic group or an amino group, and Z ₂ forms a 5- or 6-membered aromatic heterocyclic ring. (N represents an aromatic carbocyclic group or an aromatic heterocyclic group, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1).
(4 )
The semiconductor for photoelectric conversion materials characterized by including the metal complex which has at least 1 sort (s) of the compound represented by General formula (5)-(8) as a ligand.

(Wherein R ₄ represents an alkyl group, an aryl group, a heterocyclic group or an amino group, and Z ₁ and Z ₂ represent a nonmetallic atomic group necessary for forming a 5- or 6-membered aromatic heterocyclic ring. , Ar represents an aromatic carbocyclic group or aromatic heterocyclic group, and M represents a hydrogen atom or a salt-forming cation.)
(5 )
The semiconductor for a photoelectric conversion material according to any one of ( 1 ) to ( 4 ) , wherein the metal complex has ruthenium as a central metal.

(6 )
It is a metal oxide or a metal sulfide semiconductor, The semiconductor for photoelectric conversion materials of any one of said ( 1 ) - ( 5 ) characterized by the above-mentioned .

(7 )
The photoelectric conversion element characterized by the layer containing the semiconductor for photoelectric conversion materials of any one of said ( 1 ) - ( 6 ) being provided on the electroconductive support body.

(8 )
A solar cell comprising the photoelectric conversion element according to ( 7 ) , 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.

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

  Hereinafter, the present invention will be described in detail.

  The present invention relates to a semiconductor for a photoelectric conversion material containing a metal complex having a dye molecule as a ligand. The inclusion of the metal complex means that the metal complex dye penetrates into the porous structure of the semiconductor when the semiconductor has a porous structure such as adsorption to the surface of the semiconductor serving as the base. An embodiment can be mentioned, and this means an embodiment in which sensitization of a semiconductor can be performed.

  As a result of intensive studies to solve the current problems in the dye-sensitized solar cells, the present inventors have described the general formulas (1) to (1) to (1) to (7), respectively. A metal complex dye having a compound (dye) having a specific structure represented by (8) as a ligand is found and described in the present invention by a semiconductor for a photoelectric conversion material sensitized with the metal complex dye. That is, it succeeded in obtaining a semiconductor for a photoelectric conversion material that exhibits high photoelectric conversion efficiency and excellent stability.

<< Semiconductor for photoelectric conversion material >>
As a semiconductor used as a base material used in the semiconductor for photoelectric conversion material of the present invention, silicon, germanium, simple substance, periodic table (also referred to as element periodic table), Group 3 to Group 5, Group 13 to Group A compound having a group 15 element, a metal chalcogenide (eg, oxide, sulfide, selenide, etc.), 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 , metal oxides or metal sulfide semiconductors such as CdS, PbS, etc., and TiO ₂ or Nb ₂ O ₅ is more preferably used, and among these, TiO ₂ is 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 subjecting the semiconductor to sensitization treatment with a metal complex (dye) having any one of the compounds represented by the general formulas (1) to (8) as a ligand, the object described in the present invention is achieved. One of the semiconductors for photoelectric conversion materials of the present invention showing high photoelectric conversion efficiency and excellent stability can be obtained.

  Hereinafter, the compounds represented by the general formulas (1) to (8) will be described.

<< Compounds Represented by General Formulas (1) and (2) >>
The compounds represented by the general formulas (1) and (2) according to the present invention will be described.

In the general formulas (1) and (2), R _{1 to} R ₃ represent a hydrogen atom or a substituent, R ₄ represents an alkyl group, an aryl group, a heterocyclic group or an amino group, and Z ₁ is a 5- or 6-membered member. Represents a nonmetallic atomic group necessary for forming an aromatic heterocyclic ring, and Ar is necessary for the compound represented by the general formula (1) or (2) to absorb from the visible region to the near infrared region. An aromatic carbocyclic group or an aromatic heterocyclic group, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.

In the general formulas (1) and (2), the substituent represented by R _{1 to} R ₃ 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) Group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group etc.), bicycloalkyl group (For example, bicyclo [1,2,2] heptan-2-yl group, bicyclo [2,2,2] octane-3-yl group, etc.), alkenyl group (for example, vinyl group, allyl group, propylenyl group, octenyl) Group), cycloalkenyl group (for example, 2-cyclopenten-1-yl group, 2-cyclohexen-1-yl group, etc.), Chloalkenyl groups (for example, bicyclo [2,2,1] hept-2-en-1-yl group, bicyclo [2,2,2] oct-2-en-4-yl group), alkynyl groups (for example, , Propargyl group, ethynyl group, trimethylsilylethynyl group, etc.), aryl group (eg, phenyl group, naphthyl group, p-tolyl group, m-chlorophenyl group, o-hexadecanoylaminophenyl group, etc.), heterocyclic group (eg, , 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-tetrahydropyranyloxy group, pyri Diloxy group, thiazolyloxy group, oxazolyloxy group, imidazolyloxy group, etc.), halogen atom (eg, chlorine atom, bromine atom, iodine atom, fluorine atom), alkoxyl group (eg, methoxy group, ethoxy group, propyloxy) Group, tert-butoxy group, pentyloxy group, hexyloxy 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) Group, Xylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), heterocyclic thio group (eg, pyridylthio group, Thiazolylthio group, oxazolylthio group, imidazolylthio group, furylthio group, pyrrolylthio group, etc.), alkoxycarbonyl group (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.) , Aryloxycarbonyl groups (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl groups (for example, aminosulfonyl group, methylaminosulfonyl group, dimethyl) Minosulfonyl 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.), 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, pyridylcarbonyl group, etc.), acyloxy group (eg, formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy 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 groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylene Carbonylamino 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, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthyl Aminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), alkylsulfinyl group or arylsulfinyl group (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, cyclopentylamino group, 2-ethylhexylamino group, dodecylamine Mino group, anilino group, N-methylanilino group, diphenylamino group, naphthylamino group, 2-pyridylamino group, etc.), silyloxy group (for example, trimethylsilyloxy group, tert-butyldimethylsilyloxy group, etc.), aminocarbonyloxy group ( For example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyloxy group, etc.) An alkoxycarbonyloxy group (eg, methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyloxy group, etc.), aryloxycarbonyloxy group (eg, phenoxycarbonyloxy group) Group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group, etc.), alkoxycarbonylamino group (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 group (for example, 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, etc., heterocyclic azo group (for example, pyridylazo group, thiazolylazo group, oxazolylazo group, imidazolyl) Azo 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), phosphinyl group (for example, phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group, etc.), phosphinyloxy group (for example, diphenoxyphosphinyloxy group, dioctyloxy) Phosphinyloxy group, etc.) Mino group (for example, dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, etc.), silyl group (for example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group, etc.), cyano group, nitro group, A hydroxyl group, a sulfo group, a carboxyl group and the like can be mentioned. R1 to R3 are preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, an alkoxy group, an alkoxycarbonyl group, a carboxyl group, and R ₁ and R ₂ or it may form a ring of 5 or 6 membered or between R ₂ and R ₃ with R _3, may be condensed with another ring structure.

In the general formulas (1) and (2), the group represented by R ₄ is the same group as the alkyl group, aryl group, and heterocyclic group mentioned as the substituent represented by R _{1 to} R _3. Represents an amino group, preferably an alkyl group or an amino group.

In the general formula (1) and (2), 5 or 6 membered aromatic heterocyclic ring as the group pyridyl group formed by Z _1, Piraji two group, pyrimidine two group, Piridaji two group, triazine two group, an oxazolyl group, a thiazolyl group, a pyrazolyl group, an imidazolyl group, a pyrrolyl group, selenazolyl group, a triazolyl group, a tetrazolyl group, and the like, preferably pyridyl, Piraji two group, triazine two group, oxazolyl group, Examples include a thiazolyl group and a pyrazolyl group.

In the general formula (1) and (2), the aromatic carbocyclic group represented by Ar, a phenyl group, a naphthyl group, and the aromatic heterocyclic group, also for example Chie sulfonyl group in addition to the above, furyl group, a pyrrolyl group, a thiazolyl group and the like, preferably a phenyl group, a pyridyl group, Chie group, a furyl group, a thiazolyl group, and the like. Further, Ar may have a substituent, and examples of the substituent include the groups described for R _{1 to} R ₃ , preferably an electron donating property such as an alkyl group, an alkoxy group, and a substituted amino group. A 5- to 6-membered ring may be formed by the substituent and Ar (for example, when Ar is a phenyl group and the substituent is a dialkylamino group, a julolidine ring may be formed).

In the compounds represented by the general formulas (1) and (2), M represents a hydrogen atom or a salt-forming cation. Examples of the salt-forming cation represented by M include sodium, potassium, magnesium, calcium and the like. The compounds represented by the general formulas (1) and (2) may form a salt with these ions. In addition, the salt-forming cation represented by M is a cation obtained by protonating an organic base such as pyridine, piperidine, triethylamine, aniline, diazabicycloundecene, and forms a salt with these cations. Good. M is preferably a hydrogen atom or a sodium ion, a potassium ion, a triethylammonium ion or the like, and more preferably a hydrogen atom or a sodium ion.
In the general formulas (1) and (2), n represents 0 or 1, but is preferably 0.

<< Compounds Represented by General Formulas (3) and (4) >>
Next, general formulas (3) and (4) will be described.

In the compounds represented by the general formulas (3) and (4), R _{1 to} R ₃ represent a hydrogen atom or a substituent, R ₄ represents an alkyl group, an aryl group, a heterocyclic group, or an amino group, and Z ₂ represents Represents a nonmetallic atomic group necessary for forming a 5- or 6-membered aromatic heterocyclic ring, and Ar absorbs the compound represented by the general formula (3) or (4) from the visible region to the near infrared region. Represents an aromatic carbocyclic group or aromatic heterocyclic group necessary for having M, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.

R < ₁ > -R < ₄ >, Ar, n, and M said here are synonymous with General formula (1) and (2), and are the same also about a preferable range. Moreover, the 5- or 6-membered aromatic heterocycle formed by the nonmetallic atomic group represented by Z ₂ has the same meaning as the aromatic heterocycle formed by Z _{1 in} the general formulas (1) and (2). The same applies to the preferred range.

<< Compounds Represented by General Formulas (5) to (8) >>
Next, general formulas (5) to (8) will be described.

In the general formulas (5) to (8), R ₄ represents an alkyl group, an aryl group, a heterocyclic group or an amino group, and Z ₁ and Z ₂ are necessary for forming a 5- or 6-membered aromatic heterocyclic ring. Represents a nonmetallic atomic group, and Ar represents an aromatic carbocyclic group or aromatic heterocyclic ring necessary for the compound represented by the general formulas (5) to (8) to absorb from the visible region to the near infrared region. Represents a group, and M represents a hydrogen atom or a salt-forming cation.

R ₄ , Ar, Z ₁ , Z ₂ and M mentioned here have the same meaning as in the general formulas (1) to (4), and the same applies to the preferred ranges.

  In the metal complex dye of the present invention, at least one compound represented by the general formulas (1) to (8) can be used as a ligand. Examples thereof include those described in JP-A-2000-251957, JP-A-2000-311723, JP-A-2000-323191, JP-A-2001-6760, JP-A-2001-59062, JP-A-2001-60467, and the like. Specifically, halogen ion, hydroxide ion, ammonia, pyridine, amine (such as methylamine, diethylamine, tributylamine, etc.), cyanide ion, cyanate ion, thiolate ion, thiocyanate ion, and bipyridines, aminopolycarboxylic acid Various chelate ligands such as acids, 8-hydroxyquinoline and the like can be mentioned, and the chelate ligands are exemplified in “Chelical Chemistry” by Keihei Ueno.

  As bidentate ligands, acyloxy group, oxalylene group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithiocarbonate A ligand coordinated by a group, an alkylthio group or an arylthio group, or a ligand comprising a dialkyl ketone or a carbonamide is preferred.

  As a monodentate ligand, a ligand coordinated by an acyl group, a carbonyl group, a thiocyanate group, an isocyanate group, a cyanate group, an isocyanate group, a halogen ion, a cyano group, an alkylthio group, an arylthio group, an alkoxy group or an aryloxy group Or a ligand composed of dialkyl ketone or carbonamide is preferred.

  Specific examples are shown below, but the present invention is not limited thereto. It should be noted that the structural formula shown here is only one limit structure among a number of possible resonance structures, and the distinction between a covalent bond (shown by a solid line-) and a coordination bond (shown by a dotted line ...) is also formal. It does not represent an absolute distinction.

  In addition, the following ligands are also preferable.

  The metal atom is preferably an atom from the fourth period Sc to Zn on the periodic table, an atom from the fifth period Y to Cd, and an atom from the sixth period La to Hg. Mn, Fe, Co, Ni, Cu Zn, Ru, and Os are more preferable, and Ru is most preferable.

  Specific examples of the compounds represented by the general formulas (1) to (8) and the metal complex dye according to the present invention are shown below, but the present invention is not limited to these.

  First, specific examples of the compounds represented by the general formulas (1) to (8) are shown.

  Next, specific examples of metal complex dyes having the compounds represented by the general formulas (1) to (8) as ligands are shown.

  The compounds represented by the general formulas (1) to (8) according to the present invention include, for example, JP-A-10-193807, JP-A-11-78258, JP-A-2001-92091, and the like, The Cyanine Dyes and Related. Compounds, F.M. Hamer, Interscience Publishers, 1964 (Zacyanin Soybean and Relaided Compounds, F. Harmer, Interscience Publishers, 1964), JP-A-10-60296, JP-A-2000-191934, etc. Can be synthesized with reference to

  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 No. 1)
(1) I-1 synthesis route

(2) Synthesis of Intermediate 4 Intermediate 2 is added to 21.0 g and ethanol 200 ml, to which 10.9 g of Intermediate 1 and then 12.0 g of acetic acid are added with stirring. In order to generate heat, the mixture is stirred for 10 minutes and then heated to reflux for 2 hours. After completion of the reaction, ethanol is distilled off, ethyl acetate is added and the salt is filtered. Further, after distilling off ethyl acetate, ethanol is added and the mixture is cooled with stirring. Crystals are precipitated. The crystals are collected by filtration and washed with acetonitrile (intermediate 3).

  To the obtained crystals, 250 ml of ethanol is added, an aqueous solution in which 10 g of sodium hydroxide is dissolved in 50 ml of water is added, and the mixture is heated to reflux for 2 hours. Acidify with hydrochloric acid (pH of about 1) and crystallize when stirred and cooled. Filter and wash with ethanol-water mixed solution. 14.8g of intermediate 4 which is a yellowish white crystal | crystallization was obtained. The product was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product (Intermediate 4).

(3) Synthesis of Exemplary Compound I-1 60 ml of toluene, 0.90 g of morpholine and 2.02 g of intermediate 5 are added to 2.05 g of intermediate 4 and heated to reflux for 2 hours. After completion of the reaction, the reaction mixture was cooled and the crystals were filtered. The crystals were washed with toluene and ethyl acetate in this order to obtain 3.24 g of Exemplified Compound I-1. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

(4) Exemplified Compound No. Synthesis of 1 0.76 g of Exemplified Compound I-1, 0.28 g of ruthenium chloride and 5 ml of DMF were added and sufficiently purged with nitrogen, followed by heating to reflux at 160 ° C. for 6 hours in a nitrogen atmosphere. After the completion of the reaction, the reaction mixture was cooled, dropped into 40 ml of methanol, stirred under cooling, and the precipitated crystals were filtered (0.70 g). Next, KNCS, 2.2 g, is dissolved in 4 ml of pure water purged with nitrogen, 20 ml of DMF substituted with nitrogen, and crystals collected by filtration are added. After nitrogen substitution again, the mixture is reacted at 160 ° C. in a nitrogen atmosphere for 4 hours. After allowing to cool, the reaction solution was added dropwise to nitrogen-substituted water, cooled and stirred, and the precipitated crystals were filtered. The crystals were washed in the order of pure water and ethyl acetate. 0.52 g of 1 was obtained. It identified by the MASS spectrum and confirmed that it was the target object.

Synthesis example 2
(Synthesis of Exemplified Compound No. 26)
(1) Synthesis route

(2) Synthesis of Exemplified Compound III-1 To 2.29 g of Intermediate 6 is added 60 ml of toluene, 0.90 g of morpholine and 2.02 g of Intermediate 5 and heated to reflux for 2 hours. After completion of the reaction, the reaction mixture was cooled and the crystals were filtered. The crystals were washed with toluene and ethyl acetate in this order to obtain 3.56 g of Exemplified Compound III-1. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

(3) Exemplified Compound No. Synthesis of No. 26 0.80 g of Exemplified Compound III-1, 0.28 g of ruthenium chloride and 5 ml of DMF were added, and after sufficient nitrogen substitution, the mixture was heated to reflux at 160 ° C. for 6 hours in a nitrogen atmosphere. After the completion of the reaction, the reaction mixture was cooled, dropped into methanol (40 ml), cooled and stirred, and the precipitated crystals were filtered (0.74 g). Next, KNCS, 2.2 g, is dissolved in 4 ml of pure water purged with nitrogen, 20 ml of DMF substituted with nitrogen, and crystals collected by filtration are added. After nitrogen substitution again, the mixture is reacted at 160 ° C. in a nitrogen atmosphere for 4 hours. After allowing to cool, the reaction solution was added dropwise to nitrogen-substituted water, cooled and stirred, and the precipitated crystals were filtered. The crystals were washed in the order of pure water and ethyl acetate. 0.56 g of 26 was obtained. It identified by the MASS spectrum and confirmed that it was the target object.

Synthesis example 3
(Synthesis of Exemplified Compound No. 36)
(1) Synthesis route

(2) Synthesis of Exemplified Compound IV-1 To 2.05 g of Intermediate 7 is added 60 ml of toluene, 0.90 g of morpholine and 2.02 g of Intermediate 5 and heated to reflux for 2 hours. After completion of the reaction, the reaction mixture was cooled and the crystals were filtered. The crystals were washed with toluene and ethyl acetate in this order to obtain 3.24 g of Exemplified Compound IV-1. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

(3) Exemplified Compound No. Synthesis of 36 0.75 g of Exemplified Compound IV-1, 0.28 g of Ruthenium Chloride and 5 ml of DMF were added and sufficiently purged with nitrogen, followed by heating under reflux at 160 ° C. for 6 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled, dropped into methanol (40 ml), cooled and stirred, and the precipitated crystals were filtered. The crystals were washed in the order of pure water and ethyl acetate. 36 was obtained as 0.60 g. It identified by the MASS spectrum and confirmed that it was the target object.

Synthesis example 4
(Synthesis of Exemplified Compound No. 46)
(1) Synthesis route

(2) Synthesis of Exemplary Compound V-1 To 4.10 g of intermediate compound 4, 120 ml of methanol and 21.2 ml of triethylamine are added and dissolved by stirring. Next, a solution of 13.0 g of ammonium persulfate dissolved in 20 ml of water is added, and further, a solution of 4.73 g of intermediate 7 in 20 ml of water and 20 ml of methanol is added dropwise with stirring over 20 minutes. After the completion of the dropwise addition, the mixture is stirred for 1 hour at room temperature, and then the inorganic salt deposited by filtration is filtered and washed with methanol. The filtrate is concentrated, dissolved in 200 ml of ethyl acetate, adjusted to pH 1 by adding 1 mol / l hydrochloric acid, separated, neutralized, washed with water and concentrated. The concentrate was purified by column chromatography and recrystallized from acetonitrile to obtain 6.02 g of Exemplified Compound V-1. It was identified by MASS, H-NMR, and IR spectrum, and confirmed to be the target product.

(3) Exemplified Compound No. Synthesis of 46 To 0.76 g of Exemplified Compound V-11, 0.28 g of ruthenium chloride and 5 ml of DMF were added and sufficiently substituted with nitrogen, followed by heating under reflux at 160 ° C. for 6 hours in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled, dropped into methanol: 40 ml, cooled and stirred, and the precipitated crystals were filtered (0.70 g). Next, KNCS is dissolved in 2.2 g of pure water substituted with 2.2 g of nitrogen, and 20 ml of DMF substituted with nitrogen and 20 ml of filtered crystals are added thereto. After purging with nitrogen again, the mixture is reacted at 160 ° C. in a nitrogen atmosphere for 4 hours. After allowing to cool, the reaction solution was added dropwise to nitrogen-substituted water, cooled and stirred, and the precipitated crystals were filtered. The crystals were washed with pure water and ethyl acetate in this order, and Exemplified Compound No. 0.51 g of 46 was obtained. It identified by the MASS spectrum and confirmed that it was the target object.

<< Sensitivity treatment of semiconductor for photoelectric conversion material >>
The semiconductor for a photoelectric conversion material according to the present invention includes a metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand in a semiconductor serving as a base. Becomes sensitized and the effects described in the present invention can be achieved. In the present invention, 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. .

Further, a metal complex dye having any one compound represented by the above general formulas (1) to (8) per 1 m ² of a semiconductor layer (which may be a semiconductor) as a ligand, and the total content of each compound Is preferably in the range of 0.01 mmol to 100 mmol, more preferably 0.1 mmol to 50 mmol, and particularly preferably 0.5 mmol to 20 mmol.

  When sensitizing using a metal complex dye having any one of the compounds represented by the general formulas (1) to (8) according to the present invention as a ligand, the metal complex dye is used alone. A metal complex dye having any one of the compounds represented by the general formulas (1) to (8) according to the present invention as a ligand and other compounds may be used in combination. (For example, U.S. Pat. Nos. 4,684,537, 4,927,721, 5,084,365, 5,350,644, , 463,057, 5,525,440, etc., and compounds described in JP-A-7-249790, JP-A-2000-150007, etc.) It can also be used.

  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 a metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand, the compound is dissolved in an appropriate solvent (such as ethanol). In general, a method of immersing a well-dried semiconductor in the solution for a long time is generally used.

  For photoelectric conversion materials in which a plurality of metal complex dyes having any one of the compounds represented by the general formulas (1) to (8) as a ligand are used in combination or in combination with other sensitizing dye compounds When producing a semiconductor, a mixed solution of each compound 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. Moreover, you may produce by mixing the semiconductor fine particle which adsorb | sucked the said compound independently.

  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 metal complex pigment | dye which has as a ligand any one sort of compound represented by the said General formula (1)-(8) is used. The sensitization process is performed by including the sensitization process. 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 a metal complex dye having any one of the compounds represented by the general formulas (1) to (8) according to the present invention as a ligand, the present invention includes Any dye that can spectrally sensitize such a semiconductor can be used. In order to make the wavelength range of photoelectric conversion as wide as possible and increase the conversion efficiency, it is also 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. Moreover, another pigment | dye can be adsorb | sucked on another board | substrate, and they can also be piled up.

  In the present invention, known metal complex dyes, phthalocyanine dyes, porphyrin dyes, and polymethine dyes are preferably used from a comprehensive viewpoint such as photoelectron transfer reaction activity, light durability, and photochemical stability.

Among known metal complex dyes, JP-A Nos. 2001-223037, 2001-226607, U.S. Pat. Nos. 4,927,721, 4,684,537, 5,084,365, the No. 5,350,644, the No. 5,463,057, the No. 5,525,440, JP-a-7-249750, Hei No. 10-504512, world Patent 9 8/50393 JP etc. The ruthenium complex dyes described in 1) 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.

As another example, in the case of titanium oxide, Ti (OC ₃ H ₇ ) 4 vapor heated at a low temperature (for example, 80 ° C.) after titanium oxide particles are formed on a substrate (made of glass or polymer) by electrophoresis. There are a method of adsorbing and light irradiation, a method of forming by irradiating a microwave, and the like. In addition, when zinc oxide is used, there is a method in which a zinc oxide thin film is formed by electrolytic deposition from a zinc chloride aqueous solution and used as a semiconductor.

  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 sensitization treatment with a semiconductor dye is performed by dissolving the dye in an appropriate solvent and immersing the substrate on which the semiconductor is baked 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) to (8). It is preferable that the metal complex dye having any one of the compounds represented by the above formula as a ligand can enter deep inside the semiconductor layer (semiconductor film), and the semiconductor layer (semiconductor film) is a porous structure film. Is particularly preferred.

"solvent"
The solvent used to dissolve the metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand can dissolve the compound, and the semiconductor. There is no particular limitation as long as it does not dissolve or react with the semiconductor, but moisture and gas dissolved in the solvent enter the semiconductor film and sensitize treatment such as adsorption of the compound In order to prevent hindering, it is preferable to degas 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 on which the semiconductor has been baked in the solution containing the metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand is the semiconductor layer (semiconductor film). ) And the compound penetrates deeply to sufficiently adsorb, etc., sufficiently sensitize the semiconductor, and is generated by decomposition of the compound in the solution, etc., and the decomposition product interferes with the adsorption of the compound. From the viewpoint of suppressing the temperature, it is preferably 3 hours to 48 hours, more preferably 4 hours to 24 hours under the condition of 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.

  When immersed, the solution containing the metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand is a temperature at which it does not boil unless the compound is decomposed. It may be used after being heated. 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 represented by the general formulas (1) to (8) according to the present invention after forming a semiconductor thin film as described above on a conductive support 1 as shown in FIG. It is manufactured through a process of adsorbing a metal complex dye having any one of the compounds as a ligand.

  Further, the surface area of the semiconductor thin film is increased, impurities on the surface of the semiconductor thin film are removed, the purity of the semiconductor is increased, and any one compound represented by the general formulas (1) to (8) is disposed. 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 the metal complex dye in the ligand to 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 a metal complex dye having any one of the compounds represented by the above general formulas (1) to (8) as a ligand as a semiconductor. The photosensitive layer 2 is formed by sensitizing the film. 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 treated under reduced pressure or heat to remove bubbles in the film, and any one compound represented by the general formulas (1) to (8) is coordinated. It is preferable that the metal complex dye contained in the child can enter deep inside the semiconductor film.

  When the metal complex dye having any one of the compounds represented by the general formulas (1) to (8) as a ligand is adsorbed 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.

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

  A semiconductor for a photoelectric conversion material sensitized by using a plurality of metal complex dyes having any one of the compounds represented by the general formulas (1) to (8) as a ligand in combination is used in combination. It may be prepared by dipping in a solution prepared by mixing the compounds, or by preparing a solution for each compound and dipping 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 ⁻ 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 solid polymer electrolytes include electrolytes described in JP-A No. 2001-160427, and examples of gel electrolytes include electrolytes 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.

Subsequently, in 200 ml of methanol solution, the metal complex exemplified compound No. A solution in which 5 g of 1 was dissolved was prepared, the film-like titanium oxide (semiconductor layer for photoelectric conversion material) was immersed in the support, and 1 g of trifluoroacetic acid was further added, followed by ultrasonic irradiation for 2 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 element 102 to 123": In the preparation of the present invention the photoelectric conversion element 1, a metal complex exemplified compound No. Photoelectric conversion elements 102 to 123 were obtained in the same manner except that 1 was changed to the metal complex exemplified compounds shown in Table 1 (the number of moles of the dye was the same).

<< 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-101 to SC-123 >>: After the photoelectric conversion element 1 according to the present invention is sealed with a resin, lead wires are attached, and the solar cells SC-101 to SC-SC-123 of the present invention are attached. Three lots were prepared for each.

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

<< Evaluation of photoelectric conversion characteristics of solar cells >>
The solar cells SC-101 to SC-123, SC-R1 and SC-R2 obtained above were each 100 mW / m ² by a solar simulator (manufactured by JASCO (JASCO), low energy spectral sensitivity measuring device CEP-25). Table 1 shows the short-circuit current density Jsc (mA / cm ² ) and the open-circuit voltage value Voc (V) when irradiated with light of the above intensity. 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 the comparison, the solar cell of the present invention exhibits high photoelectric conversion characteristics, and a metal complex having any one of the compounds represented by the general formulas (1) to (8) as a ligand. It turns out that it is effective to use a pigment | dye. It can also be seen that the compounds of the present invention are effective against R2. In addition, it is clear that the solar cells SC-101 to SC-123 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.

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 (8)

Formula (1) or the photoelectric conversion material for semiconductor, characterized in that it comprises a metal complex having at least one of the represented Ru compound (2) as a ligand.

(Wherein R _{1 to} R ₃ represent a hydrogen atom or an alkyl group, R ₄ represents an alkyl group, a phenyl group or an amino group, and Z ₁ together with a carbon atom and a nitrogen atom together with a pyridyl group, a pyrazinyl group and a pyrimidinyl group) Represents a nonmetallic atomic group necessary for forming a pyridazinyl group, triazinyl group, oxazolyl group, thiazolyl group, pyrazolyl group, imidazolyl group or triazolyl group, Ar represents a phenyl group, naphthyl group, thienyl group, furyl group or thiazolyl Represents a group, M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.) The semiconductor for photoelectric conversion materials characterized by including the metal complex which has at least 1 sort (s) of the compound represented by general formula ( 3 ) or ( 4 ) as a ligand.

(Wherein R _{1 to} R ₃ represent a hydrogen atom or an alkyl group , R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a thiazolyl group, a pyrazolyl group or an amino group, and Z ₂ together with a carbon atom and a nitrogen atom) Represents a nonmetallic atomic group necessary for forming a pyridyl group, a pyrazinyl group, a pyrimidinyl group, an oxazolyl group, a thiazolyl group, a pyrazolyl group or an imidazolyl group , and Ar represents a phenyl group, a thienyl group, a furyl group or a thiazolyl group. , M represents a hydrogen atom or a salt-forming cation, and n represents 0 or 1.) The semiconductor for photoelectric conversion materials characterized by including the metal complex which has at least 1 sort (s) of the compound represented by general formula ( 5 ) - ( 7 ) as a ligand.

( Wherein R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a pyrazolyl group, a thiazolyl group, a pyrazinyl group or an amino group, and Z ₁ and Z ₂ together with a carbon atom and a nitrogen atom, a pyridyl group, a pyrazinyl group, an oxazolyl group) Represents a nonmetallic atomic group necessary for forming a group, thiazolyl group, pyrazolyl group or imidazolyl group , Ar represents a phenyl group, thienyl group, furyl group or thiazolyl group, and M represents a hydrogen atom or a salt-forming cation Represents .) Formula photoelectric conversion material for semiconductor, characterized in that it comprises a metal complex having as a ligand a compound represented by (8).

(In the formula , R ₄ represents an alkyl group, a phenyl group, a pyridyl group, a pyrazolyl group, a thiazolyl group, a pyrazinyl group or an amino group, Ar represents a phenyl group, a thienyl group, a furyl group or a thiazolyl group, and M represents a hydrogen atom. Or represents a salt-forming cation.) The semiconductor for photoelectric conversion materials according to any one of claims 1 to 4, wherein the metal complex has ruthenium as a central metal. The semiconductor for a photoelectric conversion material according to claim 1, wherein the semiconductor according to the semiconductor for a photoelectric conversion material is a metal oxide or a metal sulfide semiconductor. A layer containing the semiconductor for a photoelectric conversion material according to claim 1 is provided on a conductive support. The photoelectric conversion element of Claim 7 has a charge-transfer layer and a counter electrode, The solar cell characterized by the above-mentioned.

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