JP2012033443A - Photoelectric conversion element and photoelectrochemical battery, and dye used for those - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element capable of enhancing durability while achieving high photoelectric conversion efficiency, and to provide a photoelectrochemical battery using the same, and dye used for those.SOLUTION: Provided is a photoelectric conversion element having a photoreceptor layer containing organic sensitizing dye and semiconductor fine particles. A dye having an adsorption equilibrium constant to titanium oxide in a solvent of 300 g/L or more and 10,000 g/L or less is applied as the organic sensitizing dye. In addition, provided is organic sensitizing dye for a photoelectric conversion element, in which an adsorption equilibrium constant to titanium oxide in a solvent is 300 g/L or more and 10,000 g/L or less.

Description

  The present invention relates to a photoelectric conversion element, a photoelectrochemical cell, and a dye used therefor.

  Photoelectric conversion elements are used in various optical sensors, copying machines, solar cells, and the like. Various types of photoelectric conversion elements have been put to practical use, such as those using metals, semiconductors, organic pigments and dyes, or combinations thereof. Above all, a solar cell using non-depleting solar energy does not require fuel, and its full-scale practical use is expected greatly as it uses inexhaustible clean energy. Among these, silicon solar cells have been researched and developed for a long time. It is spreading due to the policy considerations of each country. However, silicon is an inorganic material, and its throughput and molecular modification are naturally limited.

  Therefore, research on dye-sensitized solar cells has been vigorously conducted. In particular, Graetzel et al. Of Lausanne University of Technology in Switzerland developed a dye-sensitized solar cell in which a dye composed of a ruthenium complex was fixed on the surface of a porous titanium oxide thin film, and realized conversion efficiency comparable to amorphous silicon. As a result, dye-sensitized solar cells have attracted a great deal of attention from researchers around the world.

  In particular, from the perspective of responding in Japan and other regions where energy resources are scarce, or accelerating the replacement of fossil fuels with green energy that does not emit carbon dioxide, the research and development of solar cells is more proactive in various fields. It has been tackled. The current mainstream is based on silicon (Si), but a great deal of attention is being focused on next-generation technologies that substitute for the above-mentioned viewpoints such as throughput. In particular, organic solar cells are expected to be light and low in cost and excellent in environmental compatibility.

  Patent Documents 1 and 2 disclose dye-sensitized solar cells using metal complex dyes. The dye disclosed therein has light absorption ability in a suitable wavelength region, and realizes good photoelectric conversion efficiency. On the other hand, Patent Documents 3 and 4 disclose organic dye-based sensitizing dyes, which are also supposed to realize high photoelectric conversion efficiency. It is disclosed that the sensitizing dye disclosed in Patent Document 5 has adsorption stability by the action of its specific adsorptive group and can suppress elution into the electrolyte medium.

JP 2001-291534 A International Publication No. 2007/091525 Pamphlet International Publication No. 2007/119525 Pamphlet International Publication No. 2007/134939 Pamphlet JP 2007-257924 A

As described above, in the development of dye-sensitized solar cells, attempts have been made mainly to improve the photoelectric conversion efficiency by modifying the chemical structure of the sensitizing dye. Japanese Patent Application Laid-Open No. 2004-228561 also has a description about partially improving durability, but details regarding the degree of improvement are unclear. That is, practical practical knowledge has hardly been obtained about the durability of solar cells or photoelectric conversion elements.
Then, this invention aims at provision of the photoelectric conversion element which implement | achieves high photoelectric conversion efficiency, and can also improve durability further, a photoelectrochemical cell using the same, and the pigment | dye used therefor.

[一般式（１Ａ）において、Ｒは水素原子又は置換基を表す。ＲがＸ^１、Ｘ^２、及び/又はＸ^３で示される環構造を形成してもよい。Ｘ^１、Ｘ^２、及びＸ^３は同じであっても異なっていてもよい。なお、式中、酸性基Ａを示していないが、分子内に酸性基Ａを１つ以上有している。]
（５）前記有機増感色素が下記一般式（２）又は（４）で示されることを特徴とする（１）〜（４）のいずれかに記載の光電変換素子。

［一般式（２）において、Ｘはベンゼン環と連結して含窒素４−７員環を形成するのに必要な非金属原子群を表す。Ｒ^１は水素原子、脂肪族基、芳香族基又は炭素原子で結合する複素環基を表す。Ｒ^２〜Ｒ^９は水素原子又は置換基を表し、置換基のうち少なくとも一つは一般式（３）で示される色素残基を表す。一般式（３）においてＲ^１０、Ｒ^１１、及びＲ^１３は、それぞれ独立して、水素原子、脂肪族基、芳香族基、又は複素環基を表す。ｒは０以上の整数を示す。一般式（３）における炭素−炭素二重結合は、Ｅ型、又はＺ型のいずれであってもよい。Ｒ^１２は、酸性基を少なくとも一つ有する基または酸性核を表す。］
［一般式（４）中、Ａは炭素−窒素結合とともに環を形成するために必要な原子群を表す。Ｙ^１とＹ^２は少なくともどちらか一方は酸性基を表し、両方とも酸性基を表す場合は、互いに同じでも異なっていてもよく、一方のみが酸性基を表す場合は、他方は電子求引基を表す。Ｄは色素残基を表し、ｎは１以上の整数を表す。Ｌは、単結合又は２価の連結基を表す。Ｙ^３は酸性基を表す。］
（６）前記有機増感色素が下記一般式（５）で示されることを特徴とする（１）〜（５）のいずれかに記載の光電変換素子。

［一般式（５）において、Ｒ^１〜Ｒ^３、Ｒ^５、Ｒ^６、Ｒ^８〜Ｒ^１３は、それぞれ一般式（２）及び一般式（３）におけるＲ^１〜Ｒ^３、Ｒ^５、Ｒ^６、Ｒ^８〜Ｒ^１３と同義である。］
（７）前記有機増感色素が、前記酸化チタンに対する吸着平衡定数が５００ｇ／Ｌ以上７，０００ｇ／Ｌ以下の色素であることを特徴とする（１）〜（６）のいずれかに記載の光電変換素子。
（８）前記有機増感色素を吸着する際の溶媒が以下の（ａ）〜（ｌ）からなる群より選ばれるものである（１）〜（７）のいずれかに記載の光電変換素子。
（ａ）炭酸エステル類
例えばエチレンカーボネート、プロピレンカーボネー５０ト、ビニレンカーボネート、ブチレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、メチルエチルカーボネート、ジプロピルカーボネート等が好ましい。
（ｂ）ラクトン類
例えばγ−ブチロラクトン、γ−バレロラクトン、γ−カプリロラクトン、クロトラクトン、γ−カプロラクトン、δ−バレロラクトン等が好ましい。
（ｃ）エーテル類
例えばエチルエーテル、１，２−ジメトキシエタン、ジエトキシエタン、トリメトキシメタン、エチレングリコールジメチルエーテル、ポリエチレングリコールジメチルエーテル、１，３−ジオキソラン、１，４−ジオキサン等が好まし
い。
（ｄ）アルコール類
例えばメタノール、エタノール、エチレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、ポリエチレングリコールモノアルキルエーテル、ポリプロピレングリコールモノアルキルエーテル等が好ましい。
（ｅ）グリコール類
例えばエチレングリコール、プロピレングリコール、ポリエチレングリコール、ポリプロピレングリコール、グリセリン等が好ましい。
（ｆ）グリコールエーテル類
例えばエチレングリコールジアルキルエーテル、プロピレングリコールジアルキルエーテル、ポリエチレングリコールジアルキルエーテル、ポリプロピレングリコールジアルキルエーテル等が好ましい。
（ｇ）テトラヒドロフラン類
例えばテトラヒドロフラン、２−メチルテトラヒドロフラン等が好ましい。
（ｈ）ニトリル類
例えばアセトニトリル、グルタロジニトリル、プロピオニトリル、メトキシアセトニトリル、ベンゾニトリル等が好ましい。
（ｉ）カルボン酸エステル類
例えばギ酸メチル、酢酸メチル、酢酸エチル、プロピオン酸メチル等が好ましい。
（ｊ）リン酸トリエステル類
例えばリン酸トリメチル、リン酸トリエチル等が好ましい。
（ｋ）複素環化合物類
例えばＮ−メチルピロリドン、４−メチル−１，３−ジオキサン、２−メチル−１，３−ジオキソラン、３−メチル−２−オキサゾリジノン、１，３−プロパンサルトン、スルホラン等が好ましい。
（ｌ）その他
ジメチルスルホキシド、ホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、ニトロメタン等の非プロトン性有機溶媒、特開２００１−２３７０００（Ｐ２００１−２３７０００Ａ）。
（９）前記有機増感色素を、吸着させる半導体材料の単位表面積に対して５×１０^−８〜１×１０^−６ｍｏｌ／ｃｍ^２の範囲で含有させることを特徴とする（１）〜（８）のいずれか１項に記載の光電変換素子。
（１０）前記有機増感色素と金属錯体増感色素とを組み合わせた複合増感色素を用いることを特徴とする（１）〜（９）のいずれか１項に記載の光電変換素子。
（１１）前記金属錯体増感色素が下記一般式（１３）で表される（１０）に記載の光電変換素子。

Ｍｚ（ＬＬ^１１）ｍ_１１（ＬＬ^１２）ｍ_１２（Ｘ）ｍ_１３・ＤＩ 一般式（１３）

［一般式（１３）において、Ｍｚは金属原子を表し、ＬＬ^１１は下記一般式（１４）で表される２座又は３座の配位子であり、ＬＬ^１２は下記一般式（１５）で表される２座又は３座の配位子である。
Ｘはアシルオキシ基、アシルチオ基、チオアシルオキシ基、チオアシルチオ基、アシルアミノオキシ基、チオカルバメート基、ジチオカルバメート基、チオカルボネート基、ジチオカルボネート基、トリチオカルボネート基、アシル基、チオシアネート基、イソチオシアネート基、シアネート基、イソシアネート基、シアノ基、アルキルチオ基、アリールチオ基、アルコキシ基およびアリールオキシ基からなる群から選ばれた基で配位する１座又は２座の配位子、あるいはハロゲン原子、カルボニル、ジアルキルケトン、１，３−ジケトン、カルボンアミド、チオカルボンアミドまたはチオ尿素からなる１座または２座の配位子を表す。
ｍ１１は０〜３の整数を表し、ｍ１１が２以上のとき、ＬＬ^１１は同じでも異なっていてもよい。ｍ１２は０〜３の整数を表し、ｍ１２が２のとき、ＬＬ^１２は同じでも異なっていてもよい。ただし、ｍ１１とｍ１２のうち少なくとも一方は１以上の整数である。
ｍ１３は０〜２の整数を表し、ｍ１３が２のとき、Ｘは同じでも異なっていてもよく、Ｘ同士が連結していてもよい。
ＤＩは一般式（１３）において、電荷を中和させるのに対イオンが必要な場合の対イオンを表す。］

［一般式（１４）において、Ｒ^１０１及びＲ^１０２はそれぞれ独立に、カルボキシル基、スルホン酸基、ヒドロキシル基、ヒドロキサム酸基、ホスホリル基またはホスホニル基を表す。Ｒ^１０３及びＲ^１０４はそれぞれ独立に置換基を表し、Ｒ^１０５及びＲ^１０６はそれぞれ独立にアリール基又はヘテロ環基を表す。ｄ１及びｄ２はそれぞれ０以上の整数を表す。
Ｌ^１及びＬ^２はそれぞれ独立に、置換もしくは無置換のエテニレン基及び／又はエチニレン基からなり、Ｌ^１及びＬ^２が結合しているピリジン環と共役している。
ａ１及びａ２はそれぞれ独立に０〜３の整数を表し、ａ１が２以上のときＲ^１０１は同じでも異なっていてもよく、ａ２が２以上のときＲ^１０２は同じでも異なっていてもよく、ｂ１及びｂ２はそれぞれ独立に０〜３の整数を表す。ｂ１が２以上のときＲ^１０３は同じでも異なっていてもよく、Ｒ^１０３は互いに連結して環を形成してもよく、ｂ２が２以上のときＲ^１０４は同じでも異なっていてもよく、Ｒ^１０４は互いに連結して環を形成してもよい。ｂ１及びｂ２が共に１以上のとき、Ｒ^１０３とＲ^１０４が連結して環を形成してもよい。ｄ３は０以上の整数である。］

［一般式（１５）において、Ｚａ、Ｚｂ及びＺｃはそれぞれ独立に、５又は６員環を形成しうる非金属原子群を表し、それぞれ独立に酸性基を有していてもよい。ｃは０又は１を表す。］
（１２）（１）〜（１１）のいずれか１項に記載の光電変換素子を備えたことを特徴とする光電気化学電池。
（１３）溶媒中での酸化チタンに対する吸着平衡定数が３００ｇ／Ｌ以上１０，０００ｇ／Ｌ以下である、光電変換素子用の有機増感色素。 The object of the present invention has been achieved by the following means.
(1) A photoelectric conversion element comprising a photoreceptor layer having an organic sensitizing dye and semiconductor fine particles, wherein the organic sensitizing dye has an adsorption equilibrium constant of 300 g / L or more for titanium oxide in a solvent, A photoelectric conversion element characterized by applying a pigment of 000 g / L or less.
(2) The photoelectric conversion element as described in (1), wherein the organic sensitizing dye is represented by the following general formula (1).
Dye- (A) _n1 ... General formula (1)
[Dye represents a dye molecule, A represents an acidic group, and n1 represents the above integer. ]
(3) The photoelectric conversion element as described in (1) or (2), wherein the organic sensitizing dye is a donor-acceptor type dye.
(4) The photoelectric conversion element according to any one of (1) to (3), wherein the organic dye is represented by a general formula (1A).

[In General Formula (1A), R represents a hydrogen atom or a substituent. R may form a ring structure represented by X ¹ , X ² , and / or X ³ . X ¹ , X ² , and X ³ may be the same or different. In addition, although acidic group A is not shown in a formula, it has one or more acidic groups A in a molecule | numerator. ]
(5) The photoelectric conversion element as described in any one of (1) to (4), wherein the organic sensitizing dye is represented by the following general formula (2) or (4).

[In General Formula (2), X represents a nonmetallic atom group required in order to couple | bond with a benzene ring and to form a nitrogen-containing 4-7 membered ring. R ¹ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded with a carbon atom. R ^{2 to} R ⁹ represent a hydrogen atom or a substituent, and at least one of the substituents represents a dye residue represented by the general formula (3). In General Formula (3), R ¹⁰ , R ¹¹ , and R ¹³ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. r represents an integer of 0 or more. The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ¹² represents a group having at least one acidic group or an acidic nucleus. ]
[In General Formula (4), A represents an atomic group required in order to form a ring with a carbon-nitrogen bond. Y ¹ and Y ² each represent an acidic group, and when both represent an acidic group, they may be the same or different from each other. When only one represents an acidic group, the other represents an electron withdrawing group. Represents. D represents a pigment residue, and n represents an integer of 1 or more. L represents a single bond or a divalent linking group. Y ³ represents an acidic group. ]
(6) The photoelectric conversion element as described in any one of (1) to (5), wherein the organic sensitizing dye is represented by the following general formula (5).

[In the general formula ^{(5), R 1 ~R 3} , R 5, R 6, R 8 ~R 13 is, ^R 1 ^{to R} 3, respectively, in the general formula (2) and the general formula ^{(3), R 5, R 6} , which is synonymous with R ^{8 to} R ¹³ . ]
(7) The organic sensitizing dye is a dye having an adsorption equilibrium constant for the titanium oxide of 500 g / L or more and 7,000 g / L or less, according to any one of (1) to (6). Photoelectric conversion element.
(8) The photoelectric conversion element according to any one of (1) to (7), wherein the solvent for adsorbing the organic sensitizing dye is selected from the group consisting of the following (a) to (l).
(A) Carbonate esters For example, ethylene carbonate, propylene carbonate 50, vinylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate and the like are preferable.
(B) Lactones For example, γ-butyrolactone, γ-valerolactone, γ-caprolactone, crotolactone, γ-caprolactone, δ-valerolactone and the like are preferable.
(C) Ethers For example, ethyl ether, 1,2-dimethoxyethane, diethoxyethane, trimethoxymethane, ethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane and the like are preferable.
(D) Alcohols For example, methanol, ethanol, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether and the like are preferable.
(E) Glycols For example, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin and the like are preferable.
(F) Glycol ethers For example, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether and the like are preferable.
(G) Tetrahydrofurans For example, tetrahydrofuran, 2-methyltetrahydrofuran and the like are preferable.
(H) Nitriles For example, acetonitrile, glutarodinitrile, propionitrile, methoxyacetonitrile, benzonitrile and the like are preferable.
(I) Carboxylic acid esters For example, methyl formate, methyl acetate, ethyl acetate, methyl propionate and the like are preferable.
(J) Phosphoric acid triesters For example, trimethyl phosphate and triethyl phosphate are preferable.
(K) heterocyclic compounds such as N-methylpyrrolidone, 4-methyl-1,3-dioxane, 2-methyl-1,3-dioxolane, 3-methyl-2-oxazolidinone, 1,3-propane sultone, sulfolane Etc. are preferred.
(L) Others Aprotic organic solvents such as dimethyl sulfoxide, formamide, N, N-dimethylformamide, nitromethane, JP-A-2001-237000 (P2001-237000A).
(9) The organic sensitizing dye is contained in the range of 5 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² with respect to the unit surface area of the semiconductor material to be adsorbed (1) to ( The photoelectric conversion element according to any one of 8).
(10) The photoelectric conversion element according to any one of (1) to (9), wherein a composite sensitizing dye in which the organic sensitizing dye and a metal complex sensitizing dye are combined is used.
(11) The photoelectric conversion element according to (10), wherein the metal complex sensitizing dye is represented by the following general formula (13).

Mz (LL ¹¹ ) m ₁₁ (LL ¹² ) m ₁₂ (X) m ₁₃ · DI General formula (13)

[In General Formula (13), Mz represents a metal atom, LL ¹¹ is a bidentate or tridentate ligand represented by the following General Formula (14), and LL ¹² is represented by the following General Formula (15): The bidentate or tridentate ligand represented.
X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, A monodentate or bidentate ligand coordinated by a group selected from the group consisting of an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a halogen atom Represents a monodentate or bidentate ligand consisting of carbonyl, dialkyl ketone, 1,3-diketone, carbonamide, thiocarbonamide or thiourea.
m11 represents an integer of 0 to 3, when m11 is 2 or more, ^{LL 11} may be the same or different. m12 represents an integer of 0 to 3, when m12 is 2, ^{LL 12} may be the same or different. However, at least one of m11 and m12 is an integer of 1 or more.
m13 represents an integer of 0 to 2, and when m13 is 2, Xs may be the same or different, and Xs may be linked together.
DI represents a counter ion in the general formula (13) when a counter ion is necessary to neutralize the charge. ]

[In General Formula (14), R ¹⁰¹ and R ¹⁰² each independently represent a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group, a phosphoryl group, or a phosphonyl group. R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent, and R ¹⁰⁵ and R ¹⁰⁶ each independently represent an aryl group or a heterocyclic group. d1 and d2 each represents an integer of 0 or more.
L ¹ and L ² are each independently a substituted or unsubstituted ethenylene group and / or ethynylene group, and are conjugated to a pyridine ring to which L ¹ and L ² are bonded.
a1 and a2 each independently represent an integer of 0 to 3, R ¹⁰¹ may be the same or different when a1 is 2 or more, and R ¹⁰² may be the same or different when a2 is 2 or more, b1 And b2 each independently represents an integer of 0 to 3. When b1 is 2 or more, R ¹⁰³ may be the same or different, R ¹⁰³ may be linked to each other to form a ring, and when b2 is 2 or more, R ¹⁰⁴ may be the same or different. ¹⁰⁴ may be connected to each other to form a ring. When b1 and b2 are both 1 or ^more, may be linked to form a ring ^{R 103} and ^{R 104} are. d3 is an integer of 0 or more. ]

[In the general formula (15), Za, Zb and Zc each independently represent a non-metallic atom group capable of forming a 5- or 6-membered ring, and may each independently have an acidic group. c represents 0 or 1; ]
(12) A photoelectrochemical cell comprising the photoelectric conversion device according to any one of (1) to (11).
(13) An organic sensitizing dye for a photoelectric conversion element having an adsorption equilibrium constant for titanium oxide in a solvent of 300 g / L or more and 10,000 g / L or less.

  The photoelectric conversion element of the present invention, the photoelectrochemical cell using the same, and the dye used therefor have an excellent effect of realizing high photoelectric conversion efficiency in the photoelectric conversion element and further enhancing durability. .

It is sectional drawing shown typically about one embodiment of the photoelectric conversion element manufactured by this invention.

  A preferred embodiment of the photoelectric conversion element of the present invention will be described with reference to the drawings. As shown in FIG. 1, the photoelectric conversion element 10 includes a conductive support 1, a photosensitive layer 2, a charge transfer layer 3, and a counter electrode 4 arranged in that order on the conductive support 1. The conductive support 1 and the photoreceptor 2 constitute a light receiving electrode 5. The photoreceptor 2 has conductive fine particles 22 and a sensitizing dye 21, and the dye 21 is adsorbed on the conductive fine particles 22 at least in part (the dye is in an adsorption equilibrium state, It may be present in the partial charge transfer layer.) The conductive support 1 on which the photoreceptor 2 is formed functions as a working electrode in the photoelectric conversion element 10. The photoelectric conversion element 10 can be operated as the photoelectrochemical cell 100 by causing the external circuit 6 to work.

  The light-receiving electrode 5 is an electrode composed of a conductive support 1 and a photosensitive layer (semiconductor film) 2 of semiconductor fine particles 22 adsorbed with a dye 21 coated on the conductive support. The light incident on the photoreceptor (semiconductor film) 2 excites the dye. The excited dye has high energy electrons. Therefore, the electrons are transferred from the dye 21 to the conduction band of the semiconductor fine particles 22 and further reach the conductive support 1 by diffusion. At this time, the molecule of the dye 21 is an oxidant. The electrons on the electrode return to the oxidized dye while working in an external circuit, thereby acting as a photoelectrochemical cell. At this time, the light receiving electrode 5 functions as a negative electrode of the battery.

  The photoelectric conversion element of this embodiment has a photoreceptor having a layer of porous semiconductor fine particles on which a composite sensitizing dye described later is adsorbed on a conductive support. At this time, as described above, a part of the dye may be dissociated in the electrolyte. The photoreceptor is designed according to the purpose, and may have a single layer structure or a multilayer structure. The photoreceptor of the photoelectric conversion element of the present embodiment includes semiconductor fine particles adsorbed with a specific composite sensitizing dye, has high sensitivity, and can be used as a photoelectrochemical cell, and can obtain high conversion efficiency. Furthermore, it has high durability.

[Organic dye]
The organic sensitizing dye applied to the photoelectric conversion element of the present invention has an adsorption equilibrium constant of 300 g / L or more and 10,000 g / L or less, and 500 g / L or more and 7,000 g / L or less. It is more preferable that it is 700 g / L or more and 3000 g / L or less. The adsorption equilibrium constant at this time means a value measured by the measurement method shown in the examples unless otherwise specified. By being more than the said lower limit, the effect | action peculiar to this invention is exhibited effectively, and coexistence with high photoelectric conversion efficiency and high durability in a photoelectric conversion element is achieved. The upper limit value is defined as a practical value because the effect is saturated when it exceeds a predetermined adsorption equilibrium constant. Such an effect is exhibited without particular limitation on the type of the sensitizing dye as long as the above specific adsorption equilibrium constant is satisfied, and is particularly remarkable in the organic dyes represented by the following general formulas (2) to (5). The reason for this includes unexplained points. However, including the estimation, while having a predetermined ring structure and increasing the photoelectric conversion efficiency, such a dye structurally obtains adsorption stability within the device. May be difficult to resist, and as a result, durability may be reduced. In this respect, the adsorption equilibrium constant is increased by increasing the number of acidic groups that are adsorbing groups adsorbed on the surface of the semiconductor oxide, and the adsorption stability is ensured. As for the lower limit, in particular, when it is more than that, the amount of the dye adsorbed on the surface of the semiconductor oxide becomes sufficient, and the amount of power generation can be increased by that amount and secured. It is considered that the photoelectric conversion efficiency is maintained and complemented by considering and devising such things, and achieving high photoelectric conversion efficiency and high durability. The present invention is not construed as being limited by the above description.
As the medium, a medium suitable for the purpose of measurement is preferable, but when considering use as a photoelectric conversion element, any of the following is preferable.

(A) Carbonate esters For example, ethylene carbonate, propylene carbonate 50, vinylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate and the like are preferable.
(B) Lactones For example, γ-butyrolactone, γ-valerolactone, γ-caprolactone, crotolactone, γ-caprolactone, δ-valerolactone and the like are preferable.
(C) Ethers For example, ethyl ether, 1,2-dimethoxyethane, diethoxyethane, trimethoxymethane, ethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane and the like are preferable.
(D) Alcohols For example, methanol, ethanol, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether and the like are preferable.
(E) Glycols For example, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin and the like are preferable.
(F) Glycol ethers For example, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether and the like are preferable.
(G) Tetrahydrofurans For example, tetrahydrofuran, 2-methyltetrahydrofuran and the like are preferable.
(H) Nitriles For example, acetonitrile, glutarodinitrile, propionitrile, methoxyacetonitrile, benzonitrile and the like are preferable.
(I) Carboxylic acid esters For example, methyl formate, methyl acetate, ethyl acetate, methyl propionate and the like are preferable.
(J) Phosphoric acid triesters For example, trimethyl phosphate and triethyl phosphate are preferable.
(K) heterocyclic compounds such as N-methylpyrrolidone, 4-methyl-1,3-dioxane, 2-methyl-1,3-dioxolane, 3-methyl-2-oxazolidinone, 1,3-propane sultone, sulfolane Etc. are preferred.
(L) Others Aprotic organic solvents such as dimethyl sulfoxide, formamide, N, N-dimethylformamide, nitromethane, JP-A-2001-237000 (P2001-237000A).

  More preferably, methanol, ethanol, isopropanol, 1-methoxy 2-propanol, butanol, dimethylformamide (DMF), acetonitrile, 2-methoxyacetonitrile, 3-methoxypropionitrile, 2-methoxyethanol, 3-methoxypropanol Solvent such as toluene, water and any mixture thereof, and most preferably methanol, ethanol, ethanol: 1-methoxy 2-propanol = 1: 1 or toluene and any mixture thereof.

It is preferable that the specific organic sensitizing dye is represented by the following general formula (1).
Dye- (A) _n1 ... General formula (1)
Dye represents a dye molecule, A represents an acidic group, n1 represents an integer of 1 or more, and is preferably 2 or more.
The specific organic sensitizing dye is preferably a donor-acceptor type dye. Here, the donor-acceptor-type dye refers to a dye that causes intramolecular photoinduced electron transfer in which electrons are transferred to an acceptor site through conjugation in the molecule when the donor site is irradiated with light.

一般式（１Ａ）において、Ｒは水素原子又は置換基を表す。ＲがＸ^１、Ｘ^２、及び/又はＸ^３で示される環構造を形成してもよい。Ｘ^１、Ｘ^２、及びＸ^３は同じであっても異なっていてもよい。なお、式中、酸性基Ａを示していないが、分子内に酸性基Ａを１つ以上有している。 The specific organic sensitizing dye is preferably one represented by the following general formula (1A).

In general formula (1A), R represents a hydrogen atom or a substituent. R may form a ring structure represented by X ¹ , X ² , and / or X ³ . X ¹ , X ² , and X ³ may be the same or different. In addition, although acidic group A is not shown in a formula, it has one or more acidic groups A in a molecule | numerator.

  The specific organic sensitizing dye is more preferably represented by the following general formula (2) or (4).

一般式（２）において、Ｘはベンゼン環と連結して含窒素４−７員環を形成するのに必要な非金属原子群を表す。Ｒ^１は水素原子、脂肪族基、芳香族基又は炭素原子で結合する複素環基を表す。Ｒ^２〜Ｒ^９は水素原子又は置換基を表し、置換基のうち少なくとも一つは一般式（３）で示される色素残基を表す。一般式（３）においてＲ^１０、Ｒ^１１、及びＲ^１３は、それぞれ独立して、水素原子、脂肪族基、芳香族基、又は複素環基を表す。ｒは０以上の整数を示す。一般式（３）における炭素−炭素二重結合は、Ｅ型、又はＺ型のいずれであってもよい。Ｒ^１２は、酸性基を少なくとも一つ有する基または酸性核を表す。
一般式（４）中、Ａは炭素−窒素結合とともに環を形成するために必要な原子群を表す。Ｙ^１とＹ^２は少なくともどちらか一方は酸性基を表し、両方とも酸性基を表す場合は、互いに同じでも異なっていてもよく、一方のみが酸性基を表す場合は、他方は電子求引基を表す。Ｄは色素残基を表し、ｎは１以上の整数を表す。Ｌは、単結合又は２価の連結基を表す。Ｙ^３は酸性基を表す。
さらに前記特定の有機増感色素が下記一般式（５）で示されるものであることがさらに好ましい。

一般式（５）において、Ｒ^１〜Ｒ^３、Ｒ^５、Ｒ^６、Ｒ^８〜Ｒ^１３は、それぞれ一般式（２）及び一般式（３）におけるＲ^１〜Ｒ^３、Ｒ^５、Ｒ^６、Ｒ^８〜Ｒ^１３と同義である。

In the general formula (2), X represents a nonmetallic atom group necessary for forming a nitrogen-containing 4-7 membered ring by linking with a benzene ring. R ¹ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded with a carbon atom. R ^{2 to} R ⁹ represent a hydrogen atom or a substituent, and at least one of the substituents represents a dye residue represented by the general formula (3). In General Formula (3), R ¹⁰ , R ¹¹ , and R ¹³ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. r represents an integer of 0 or more. The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ¹² represents a group having at least one acidic group or an acidic nucleus.
In general formula (4), A represents an atomic group necessary for forming a ring together with a carbon-nitrogen bond. Y ¹ and Y ² each represent an acidic group, and when both represent an acidic group, they may be the same or different from each other. When only one represents an acidic group, the other represents an electron withdrawing group. Represents. D represents a pigment residue, and n represents an integer of 1 or more. L represents a single bond or a divalent linking group. Y ³ represents an acidic group.
Furthermore, it is more preferable that the specific organic sensitizing dye is represented by the following general formula (5).

In the general formula ^{(5), R 1 ~R 3} , R 5, R 6, R 8 ~R 13 is, ^R 1 ^{to R} 3, respectively, in the general formula (2) and the general formula ^{(3), R 5, R} 6 , R ^{8 to} R ¹³ .

  Although the specific example of the said specific sensitizing dye is shown below, this invention is limited and is not interpreted by this.

Acid group (bonding group)
The dye having the structure represented by the general formula (1) has one or more suitable acidic adsorption groups (bonding groups) for the surface of the semiconductor fine particles. It is more preferable to have 1 to 6 of these groups in the dye, and it is particularly preferable to have 1 to 4 of these groups. Carboxyl group, sulfonic acid group, hydroxyl group, hydroxamic acid group (for example, —CONHOH), phosphoryl group (for example, —OP (O) (OH) _2, etc.), phosphonyl group (for example, —P (O) (OH) _2, etc.) It is preferable that the dye has an acidic group (substituent having a dissociable proton). Of these, a carboxyl group, a sulfonic acid group, a hydroxyl group, and a phosphonyl group are preferable. In the present specification, an acidic group refers to a substituent that releases a proton. In addition, when “having a specific functional substituent” such as “having an acidic group”, the functional substituent is directly bonded to the mother nucleus within a range not impairing the effects of the present invention. In addition, it is meant to include those linked (linked) via a predetermined linking group.
Non-patent literature Langmuir, Vol. 14, no. 10, 1998, 2744-2749, it is known that an acidic group introduced into a dye is bonded to a metal atom in a metal oxide film as shown in the following figure. This bond is formed by binding of a metal atom cation and an anion of an acidic group. Therefore, the acidic group which the pigment | dye has in this invention can be interpreted as what contains all the acidic groups which can form the coupling | bonding mode of these a) -c), and can use these suitably.

  When there are two or more acidic groups, two or more metal atoms in the semiconductor oxide and the acidic group are bonded to each other, so that the distance and the three-dimensional structure between the two or more acidic groups are also important. The dyes described in the following specific examples are also examined with respect to the distance between the acidic groups, and the optimized examples are shown as preferred examples.

In the present invention, the content of the specific organic sensitizing dye is not particularly limited, but is preferably 5 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² , more preferably 1 × 10 ⁻⁷ to 8. × 10 ⁻⁷ mol / cm ² . By setting it to the lower limit value or more, it is possible to form a state in which sufficient dye for power generation is adsorbed on the semiconductor fine particles, and a sufficient short-circuit current value (Jsc) and conversion efficiency can be obtained. By setting it to the upper limit value or less, it is possible to prevent the dye molecules from adsorbing with each other instead of the semiconductor oxide, and it is possible to suppress unnecessary association between the dyes. This prevents the resistance of the battery circuit from being increased unnecessarily, and prevents excessive dyes from being decomposed by additives or light in the electrolyte and generating impurities in the battery. Moreover, the loss | disappearance of the effective component in a battery by this is prevented. In addition, the extra adsorbed dye is prevented from eluting into the electrolyte. This point is particularly important in the present invention in which a dye having a high region in the adsorption equilibrium constant is employed, and the effect can be optimized and exhibited by optimizing the application amount.
In the present invention, two or more specific organic sensitizing dyes may be used. In the present invention, the term “dye” means not only the dye compound itself but also a salt or ionized salt of an acidic group or basic group.

  The absorption maximum wavelength of the specific organic sensitizing dye (preferably the dye represented by the general formula (1)) is not particularly limited, but the maximum absorption wavelength in the solution is preferably in the range of 350 to 550 nm, more preferably. Is in the range of 400 to 500 nm, particularly preferably in the range of 420 to 480 nm.

  The method of synthesizing the dye represented by the general formula (1) can be referred to the method described in Examples below, and can be synthesized by appropriately applying a conventional method based on the method. .

  Although the preferable specific example of the organic pigment | dye represented by General formula (1) below is shown, this invention is not limited to the following specific examples.

In the present invention, the specific dye or a dye that is preferably combined, which will be described later, may have an arbitrary substituent other than the structure represented by the general formula as long as the effects of the present invention are not impaired.
Examples of the substituent in the present invention include those shown below.
・ Halogen atoms (for example, fluorine atom, chlorine atom, bromine atom, iodine atom),
-Alkyl group [Represents a linear, branched, or cyclic substituted or unsubstituted alkyl group. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl). A cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably having 5 to 30 carbon atoms). A substituted or unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), a tricyclo structure with more ring structures Domo is intended to cover. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ],
-Alkenyl group [Represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. They are alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or substituted groups having 3 to 30 carbon atoms). An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms (for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo 2,2,2] oct-2-en-4-yl).
An alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl, propargyl, trimethylsilylethynyl group, aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, For example, phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl),
Aromatic groups (for example, benzene ring, furan ring, pyrrole ring, pyridine ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, isoxazole ring, isothiazole ring, pyrimidine ring, pyrazine ring or these A ring fused with
A heterocyclic group (preferably a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, more preferably a carbon number of 3 To 30- or 5-membered aromatic heterocyclic group such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl),
・ Cyano group, ・ hydroxyl group, ・ nitro group, ・ carboxyl group,
An alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy),
An aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylamino Phenoxy),
A silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy),
A heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having 1 to 30 carbon atoms, 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy),
An acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy, acetyloxy, Pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy),
A carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms such as N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di -N-octylaminocarbonyloxy, Nn-octylcarbamoyloxy),
An alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, n-octylcarbonyloxy),
Aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, pn-hexadecyloxyphenoxycarbonyloxy ),
Amino groups (preferably amino groups, substituted or unsubstituted alkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted anilino groups having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino N-methyl-anilino, diphenylamino),
Acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, such as formylamino, acetylamino Pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino),
Aminocarbonylamino group (preferably substituted or unsubstituted aminocarbonylamino having 1 to 30 carbon atoms, such as carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino) ,
An alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms such as methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl- Methoxycarbonylamino),
An aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonylamino, p-chlorophenoxycarbonylamino, mn-octyloxyphenoxycarbonylamino) ,
A sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, such as sulfamoylamino, N, N-dimethylaminosulfonylamino, Nn-octylaminosulfonyl amino),
Alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino, Phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino),
・ Mercapto group,
An alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as methylthio, ethylthio, n-hexadecylthio),
An arylthio group (preferably a substituted or unsubstituted arylthio having 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio),
A heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio),
A sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N -Acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfamoyl),
・ Sulfo group,
Alkyl and arylsulfinyl groups (preferably substituted or unsubstituted alkylsulfinyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfinyl groups having 6 to 30 carbon atoms, such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p -Methylphenylsulfinyl),
Alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms such as methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p- Methylphenylsulfonyl),
Acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, substituted or unsubstituted carbon group having 4 to 30 carbon atoms A heterocyclic carbonyl group bonded to a carbonyl group at a carbon atom, such as acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl),
Aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl) ,
An alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl),
A carbamoyl group (preferably a substituted or unsubstituted carbamoyl having 1 to 30 carbon atoms such as carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- ( Methylsulfonyl) carbamoyl),
Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, such as phenylazo, p-chlorophenylazo, 5 -Ethylthio-1,3,4-thiadiazol-2-ylazo),
An imide group (preferably N-succinimide, N-phthalimide),
A phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino, diphenylphosphino, methylphenoxyphosphino),
A phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl, dioctyloxyphosphinyl, diethoxyphosphinyl),
A phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy),
A phosphinylamino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as dimethoxyphosphinylamino, dimethylaminophosphinylamino),
A silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, for example, trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl).
In addition, the substituent may be further substituted. In that case, the above-mentioned substituent can be mentioned as an example of a substituent.

[Metal complex sensitizing dye]

(Metal complex dye having the structure of the general formula (13))

一般式（１４）において、Ｒ^１０１及びＲ^１０２はそれぞれ独立に、カルボキシル基、スルホン酸基、ヒドロキシル基、ヒドロキサム酸基、ホスホリル基またはホスホニル基を表す。Ｒ^１０３及びＲ^１０４はそれぞれ独立に置換基を表し、Ｒ^１０５及びＲ^１０６はそれぞれ独立にアリール基又はヘテロ環基を表す。ｄ１及びｄ２はそれぞれ０以上の整数を表す。
Ｌ^１及びＬ^２はそれぞれ独立に、置換もしくは無置換のエテニレン基及び／又はエチニレン基からなり、Ｌ^１及びＬ^２が結合しているピリジン環と共役している。
ａ１及びａ２はそれぞれ独立に０〜３の整数を表し、ａ１が２以上のときＲ^１０１は同じでも異なっていてもよく、ａ２が２以上のときＲ^１０２は同じでも異なっていてもよく、ｂ１及びｂ２はそれぞれ独立に０〜３の整数を表す。ｂ１が２以上のときＲ^１０３は同じでも異なっていてもよく、Ｒ^１０３は互いに連結して環を形成してもよく、ｂ２が２以上のときＲ^１０４は同じでも異なっていてもよく、Ｒ^１０４は互いに連結して環を形成してもよい。ｂ１及びｂ２が共に１以上のとき、Ｒ^１０３とＲ^１０４が連結して環を形成してもよい。ｄは０以上の整数を表す。

一般式（１５）において、Ｚａ、Ｚｂ及びＺｃはそれぞれ独立に、５又は６員環を形成しうる非金属原子群を表し、それぞれ独立に酸性基を有していてもよい。ｃは０又は１を表す。 In the photoelectric conversion element of the present invention, it is preferable to use a combination of the dye having the specific adsorption equilibrium constant and the metal complex dye, and it is preferable to include the following metal complex dye in combination.

Mz (LL ¹¹ ) m ₁₁ (LL ¹² ) m ₁₂ (X) m ₁₃ · DI General formula (13)

In the general formula (13), Mz represents a metal atom, LL ¹¹ is a bidentate or tridentate ligand represented by the following general formula (14), and LL ¹² is represented by the following general formula (15). Are bidentate or tridentate ligands.
X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, A monodentate or bidentate ligand coordinated by a group selected from the group consisting of an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a halogen atom Represents a monodentate or bidentate ligand consisting of carbonyl, dialkyl ketone, 1,3-diketone, carbonamide, thiocarbonamide or thiourea.
m11 represents an integer of 0 to 3, when m11 is 2 or more, ^{LL 11} may be the same or different. m12 represents an integer of 0 to 3, when m12 is 2, ^{LL 12} may be the same or different. However, at least one of m11 and m12 is an integer of 1 or more.
m13 represents an integer of 0 to 2, and when m13 is 2, Xs may be the same or different, and Xs may be linked together.
DI represents a counter ion in the general formula (13) when a counter ion is necessary to neutralize the charge.

In the general formula (14), R ¹⁰¹ and R ¹⁰² each independently represent a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group, a phosphoryl group, or a phosphonyl group. R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent, and R ¹⁰⁵ and R ¹⁰⁶ each independently represent an aryl group or a heterocyclic group. d1 and d2 each represents an integer of 0 or more.
L ¹ and L ² are each independently a substituted or unsubstituted ethenylene group and / or ethynylene group, and are conjugated to a pyridine ring to which L ¹ and L ² are bonded.
a1 and a2 each independently represent an integer of 0 to 3, R ¹⁰¹ may be the same or different when a1 is 2 or more, and R ¹⁰² may be the same or different when a2 is 2 or more, b1 And b2 each independently represents an integer of 0 to 3. When b1 is 2 or more, R ¹⁰³ may be the same or different, R ¹⁰³ may be linked to each other to form a ring, and when b2 is 2 or more, R ¹⁰⁴ may be the same or different. ¹⁰⁴ may be connected to each other to form a ring. When b1 and b2 are both 1 or ^more, may be linked to form a ring ^{R 103} and ^{R 104} are. d represents an integer of 0 or more.

In the general formula (15), Za, Zb and Zc each independently represent a nonmetallic atom group capable of forming a 5- or 6-membered ring, and may each independently have an acidic group. c represents 0 or 1;

The compound represented by the general formula (13) has at least one acidic adsorption group in the molecule, and at least one of LL ¹ and LL ² preferably has the acidic adsorption group, and LL ² has the acidic adsorption group. It is more preferable to have a group because it is not affected by the electron-donating substituent. Specific acidic groups and preferred ranges thereof are the same as those described in the general formula (1).

・ Metal atom Mz
Mz represents a metal atom. Mz is preferably a metal capable of tetracoordinate or hexacoordinate, and more preferably Ru, Fe, Os, Cu, W, Cr, Mo, Ni, Pd, Pt, Co, Ir, Rh, Re, Mn Or it is Zn. Particularly preferred is Ru, Os, Zn or Cu, and most preferred is Ru.

Ligand LL ¹¹
The ligand LL ¹¹ is a bidentate or tridentate ligand represented by the general formula (14). R ¹⁰¹ and R ¹⁰² in the general formula (14) each independently represents an acidic group, A carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (preferably a hydroxamic acid group having 1 to 20 carbon atoms, for example, —CONHOH, —CONCH ₃ OH, etc.), a phosphoryl group (for example, —OP (O) (OH ₂ ) and a phosphonyl group (for example, —P (O) (OH) ₂ etc.), preferably a carboxyl group and a phosphonyl group, more preferably a carboxyl group. R ²¹ and R ²² may be substituted on any carbon atom on the pyridine ring.

In the formula, R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent, preferably an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1 -Ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably alkenyl groups having 2 to 20 carbon atoms such as vinyl, allyl, oleyl etc.), alkynyl groups (preferably carbon atoms) C2-C20 alkynyl groups such as ethynyl, butadiynyl, phenylethynyl, etc., cycloalkyl groups (preferably C3-C20 cycloalkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.) ), An aryl group (preferably having 6 to 26 carbon atoms) A reel group such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl and the like, a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy, etc.) An aryloxy group (preferably an aryloxy group having 6 to 26 carbon atoms such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), an alkoxycarbonyl group (preferably having 2 to 2 carbon atoms) 20 alkoxycarbonyl groups such as ethoxycarbonyl 2-ethylhexyloxycarbonyl, etc.), amino group (preferably an amino group having 0-20 carbon atoms, such as amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), sulfone An amide group (preferably a sulfonamido group having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc.), an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, for example, , Acetyloxy, benzoyloxy and the like), a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl etc.), an acylamino group (preferably having 1 to 1 carbon atoms). 20 acylamino groups such as acetylamino, benzoylamino, etc. ), A cyano group, or a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkoxy group. A carbonyl group, an amino group, an acylamino group, a cyano group or a halogen atom, particularly preferably an alkyl group, an alkenyl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a cyano group.

When the ligand LL ¹¹ comprises an alkyl group, an alkenyl group or the like, it may be be linear or branched and may be unsubstituted substituted. The ligand LL ¹¹ aryl group, when containing heterocyclic group, they may be a condensed ring may be monocyclic or be unsubstituted substituted.

In the general formula (14), R ¹⁰⁵ and R ¹⁰⁶ are each independently an alkyl group, one or more substituted or unsubstituted aromatic groups (preferably an aromatic group having 6 to 30 carbon atoms, such as phenyl, Substituted phenyl, naphthyl, substituted naphthyl, etc.) and / or one or more substituted or unsubstituted heterocyclic groups (preferably having 1 to 30 carbon atoms, such as 2-thienyl, 2-pyrrolyl, 2- Imidazolyl, 1-imidazolyl, 4-pyridyl, 3-indolyl), preferably a heterocyclic group having 1 to 3 electron-donating groups, more preferably thienyl. The electron donating group is preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, an acylamino group or a hydroxyl group, and is preferably an alkyl group, an alkoxy group, an amino group or a hydroxyl group. Is more preferable, and an alkyl group is particularly preferable. R ¹⁰⁵ and R ¹⁰⁶ may be the same or different, but are preferably the same.

R ¹⁰⁵ and R ¹⁰⁶ may be directly bonded to the dipyridine ring. R ¹⁰⁵ and R ¹⁰⁶ may be bonded to the dipyridine ring via L ¹ and / or L ² .
Here, L ¹ and L ² each independently represent a conjugated chain composed of a substituted or unsubstituted ethenylene group and / or an ethynylene group. L ¹ and L ² are each conjugated to the pyridine ring to which they are bonded. When the ethenylene group has a substituent, the substituent is preferably an alkyl group, and more preferably methyl. L ¹ and L ² are each independently preferably a conjugated chain having 2 to 6 carbon atoms, more preferably ethenylene, butadienylene, ethynylene, butadienylene, methylethenylene or dimethylethenylene, particularly ethenylene or butadienylene. Preferably, ethenylene is most preferred. L ¹ and L ² may be the same or different, but are preferably the same. When the conjugated chain contains a carbon-carbon double bond, each double bond may be a trans isomer, a cis isomer, or a mixture thereof. d1 and d2 each independently represents an integer of 0 or more. It is preferably an integer of 0 to 5, and more preferably an integer of 1 to 3. If d1 is 2 or more, L ¹ may be the same or different. When d2 is 2 or more, L ² may be the same or different.

d3 is an integer of 0 or more, preferably 0 or 1, and more preferably 1. a1 and a2 each independently represent an integer of 0 to 3. a1 is R ¹⁰¹ when 2 or more may be the same or different, a2 is 2 or more when R ¹⁰² may be the same or different. a1 is preferably 0 or 1, and a2 is preferably an integer of 0 to 2. In particular, when d3 is 0, a2 is preferably 1 or 2, and when d3 is 1, a2 is preferably 0 or 1. The sum of a1 and a2 is preferably an integer of 0-2.

b1 and b2 each independently represent an integer of 0 to 3, preferably an integer of 0 to 2. When b1 is 2 or more, R ¹⁰³ may be the same or different and may be connected to each other to form a ring. When b2 is 2 or more, R ¹⁰⁴ may be the same or different, and may be connected to each other to form a ring. When b1 and b2 are both 1 or more, R ¹⁰³ and R ¹⁰⁴ may be linked to form a ring. Preferable examples of the ring to be formed include a benzene ring, a pyridine ring, a thiophene ring, a pyrrole ring, a cyclohexane ring, a cyclopentane ring and the like.

A is the sum of a1 and a2 is 1 or more, when the ligand ^{LL 11} is having at least one acidic group, m11 in formula (13) is preferably 2 or 3, the two Is more preferable.

Ligand ^{LL 11} in the general formula (13), the following general formula (16-1), (16-2) or (16-3) is preferably one represented by.

In the general formulas (16-1) to (16-3), R ^{101 to} R ¹⁰⁴ , a1, a2, b1, b2, and d3 have the same meanings as those in the general formula (14).

In General Formula (16-2), R ¹⁰⁷ represents an acidic group, preferably a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group, a phosphoryl group, or a phosphonyl group, more preferably a carboxyl group or a phosphoryl group. Yes, particularly preferably a carboxyl group.

In the general formula (16-2), R ¹⁰⁸ represents a substituent, preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group or an acylamino group, more preferably An alkyl group, an alkoxy group, an amino group, or an acylamino group;

In general formulas (16-1) and (16-2), R ^{121 to} R ¹²⁴ each independently represent hydrogen, an alkyl group, an alkenyl group, or an aryl group. Preferred examples of R ^{121 to} R ¹²⁴ are the same as the preferred examples of R ¹⁰³ and R ¹⁰⁴ in formula (14). R ^{121 to} R ¹²⁴ are more preferably an alkyl group or an aryl group, and more preferably an alkyl group. When R ^{121 to} R ¹²⁴ are alkyl groups, they may further have a substituent, and the substituent is preferably an alkoxy group, a cyano group, an alkoxycarbonyl group or a carbonamido group, and particularly preferably an alkoxy group. R ¹²¹ and R ^{122 and} R ¹²³ and R ¹²⁴ may be connected to each other to form a ring. As the ring to be formed, a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring or the like is preferable.

In general formulas (16-1) to (16-2), R ¹²⁵ and R ¹²⁶ each independently represent a substituent, preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, or an aryloxy group. , An amino group, an acylamino group or a hydroxyl group, more preferably an alkyl group, an alkoxy group, an amino group or an acylamino group, and particularly preferably an alkyl group.
In the general formula (16-3), R ¹²⁷ and R ¹²⁸ are preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, an acylamino group, or a hydroxyl group, and more An alkyl group, an alkoxy group, an amino group or an acylamino group is preferable, and an alkyl group is particularly preferable.

In general formula (16-2), a3 represents the integer of 0-3, Preferably the integer of 0-2 is represented. When n is 0, a3 is preferably 1 or 2, and when n is 1, a3 is preferably 0 or 1. a3 is the ^{R 107} when two or more may be the same or different.

In general formulas (16-1) and (16-2), d1 and d2 each independently represents an integer of 0 to 4. When d1 is 1 or more, R ¹²⁵ may be linked to R ¹²¹ and / or R ¹²² to form a ring. The ring formed is preferably a piperidine ring or a pyrrolidine ring. When d1 is 2 or more, R ¹²⁵ may be the same or different, and may be linked to each other to form a ring. When d2 is 1 or more, R ¹²⁶ may be linked to R ¹²³ and / or R ¹²⁴ to form a ring. The ring formed is preferably a piperidine ring or a pyrrolidine ring. When d2 is 2 or more, R ¹²⁶ may be the same or different, and may be linked to each other to form a ring.

Ligand LL ¹²
In General Formula (13), LL ¹² represents a bidentate or tridentate ligand represented by General Formula (15).
In General Formula (15), Za, Zb, and Zc each independently represent a nonmetallic atom group that can form a 5-membered ring or a 6-membered ring. The formed 5-membered or 6-membered ring may be substituted or unsubstituted, and may be monocyclic or condensed. Za, Zb and Zc are preferably composed of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom and / or a halogen atom, and preferably form an aromatic ring. In the case of a 5-membered ring, an imidazole ring, an oxazole ring, a thiazole ring or a triazole ring is preferably formed. In the case of a 6-membered ring, a pyridine ring, a pyrimidine ring, a pyridazine ring or a pyrazine ring is preferably formed. Of these, an imidazole ring or a pyridine ring is more preferable.
In general formula (15), c represents 0 or 1. c is preferably 0, and LL ¹² is preferably a bidentate ligand.

Ligand ^{LL 12} is preferably represented by any of the following general formula (17-1) - (17-8), the formula (17-1), (17-2), (17-4 ) Or (17-6), more preferably represented by formula (17-1) or (17-2), and represented by formula (17-1). Is most preferred.

なお、一般式（１７−１）〜（１７−８）中のＲ^１５１〜Ｒ^１６６は図示の都合上１つのピリジン環に置換したように描写しているが、その環上にあっても、あるいは図示されたものとは異なる環上に結合してもよい。好ましくは、Ｎ原子を基準としてパラ位となるように置換した態様が挙げられる、

In the general formulas (17-1) to (17-8), R ^{151 to} R ¹⁶⁶ are depicted as substituted with one pyridine ring for the convenience of illustration, but even on the ring, Alternatively, it may be bonded on a ring different from that shown. Preferably, an embodiment in which substitution is made to be in the para position with respect to the N atom can be mentioned,

In general formulas (17-1) to (17-8), R ^{151 to} R ¹⁵⁸ each independently represent an acidic group. R ^{151 to} R ¹⁵⁸ are, for example, a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (preferably a hydroxamic acid group having 1 to 20 carbon atoms, such as —CONHOH, —CONCH ₃ OH, etc.), a phosphoryl group ( For example, —OP (O) (OH) ₂ etc.) or a phosphonyl group (eg —P (O) (OH) ₂ etc.) is represented. R ^{151 to} R ¹⁵⁸ are preferably a carboxyl group, a phosphoryl group, or a phosphonyl group, more preferably a carboxyl group or a phosphonyl group, and more preferably a carboxyl group.

In general formulas (17-1) to (17-8), R ^{159 to} R ¹⁶⁶ each independently represent a substituent, preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, or an alkoxy group. , Aryloxy group, alkoxycarbonyl group, amino group, acyl group, sulfonamido group, acyloxy group, carbamoyl group, acylamino group, cyano group or halogen atom, more preferably alkyl group, alkenyl group, aryl group, heterocyclic ring Group, alkoxy group, alkoxycarbonyl group, amino group, acylamino group or halogen atom, particularly preferably alkyl group, alkenyl group, alkoxy group, alkoxycarbonyl group, amino group or acylamino group.

In general formulas (17-1) to (17-8), R ^{167 to} R ¹⁷¹ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. Of these, an aliphatic group and an aromatic group are preferable. More preferably, it is an aliphatic group having a carboxyl group. When the ligand LL ² contains an alkyl group, an alkenyl group or the like, they may be linear or branched and may be unsubstituted substituted. Further, LL ² is an aryl group, when containing heterocyclic group, they may be a condensed ring may be monocyclic or unsubstituted substituted.

In the general formulas (17-1) to (17-8), R ^{151 to} R ¹⁶⁶ may be bonded to any position on the ring. E1 to e6 each independently represents an integer of 0 to 4, preferably an integer of 0 to 2. More preferably, it is 1 or 2. e7 and e8 each independently represents an integer of 0 to 4, preferably an integer of 0 to 3. More preferably, it is an integer of 1 to 3. e9 to e12 and e15 each independently represents an integer of 0 to 6, and e13, e14 and e16 each independently represents an integer of 0 to 4. e9 to e16 are each independently preferably an integer of 0 to 3.

When e1 to e8 is 2 or more, R ^{151 to} R ¹⁵⁸ may be the same or different. When e9 to e16 is 2 or more, R ^{159 to} R ¹⁶⁶ may be the same or different and are connected to each other. To form a ring.

・ Ligand X
The ligand X is an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, such as acetyloxy, benzoyloxy, salicylic acid, glycyloxy, N, N-dimethylglycyloxy, oxalylene (—OC (O) C (O) O-), etc.), an acylthio group (preferably an acylthio group having 1 to 20 carbon atoms, such as acetylthio, benzoylthio, etc.), a thioacyloxy group (preferably a thioacyloxy group having 1 to 20 carbon atoms, For example, a thioacetyloxy group (CH ₃ C (S) O—) and the like)), a thioacylthio group (preferably a thioacylthio group having 1 to 20 carbon atoms, such as thioacetylthio (CH ₃ C (S) S—) , Thiobenzoylthio (PhC (S) S—) and the like)), an acylaminooxy group (preferably an aryl having 1 to 20 carbon atoms) Silaminooxy group, for example, N-methylbenzoylaminooxy (PhC (O) N (CH ₃ ) O—), acetylaminooxy (CH ₃ C (O) NHO—), etc.)), thiocarbamate group (preferably A thiocarbamate group having 1 to 20 carbon atoms, such as N, N-diethylthiocarbamate, etc., a dithiocarbamate group (preferably a dithiocarbamate group having 1 to 20 carbon atoms, such as N-phenyldithiocarbamate, N, N-dimethyldithiocarbamate, N, N-diethyldithiocarbamate, N, N-dibenzyldithiocarbamate, etc.), a thiocarbonate group (preferably a thiocarbonate group having 1 to 20 carbon atoms, such as ethylthiocarbonate) Etc.), dithiocarbonate (preferably dithiocarbonate having 1 to 20 carbon atoms) Such as ethyl dithiocarbonate (C ₂ H ₅ OC (S) S—), etc., trithiocarbonate group (preferably a trithiocarbonate group having 1 to 20 carbon atoms, such as ethyl trithiocarbonate sulphonate _{(C 2 H 5 SC (S} ) S-) and the like), an acyl group (preferably an acyl group having 1 to 20 carbon atoms, e.g., acetyl, benzoyl, etc.), a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate Group, cyano group, alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms such as methanethio, ethylenedithio, etc.), arylthio group (preferably an arylthio group having 6 to 20 carbon atoms such as benzenethio, 1, 2 -Phenylenedithio etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as metho A monodentate or bidentate coordinated with a group selected from the group consisting of an aryloxy group (preferably an aryloxy group having 6 to 20 carbon atoms, such as phenoxy, quinoline-8-hydroxyl, etc.) A ligand, or a halogen atom (preferably a chlorine atom, a bromine atom, an iodine atom, etc.), a carbonyl (... CO), a dialkyl ketone (preferably a dialkyl ketone having 3 to 20 carbon atoms, such as acetone ((CH ₃ ) ₂ ). CO ...), etc.), 1,3-diketone (preferably having 3 to 20 carbon atoms 1,3-diketones, for example, acetylacetone _{(CH 3 C (O ...)} CH = C (O-) CH 3), tri fluoro acetylacetone _{(CF 3 C (O ...)} CH = C (O-) CH 3), dipivaloylmethane _{(tC 4 H 9 C (O} ...) CH = C (O-) tC 4 H ), Dibenzoylmethane (PhC (O ...) CH = C (O-) Ph), 3- chloro-acetylacetone _{(CH 3 C (O ...)} CCl = C (O-) CH 3) , etc.), carbonamido (preferably Is a carbonamide having 1 to 20 carbon atoms, such as CH ₃ N═C (CH ₃ ) O—, —OC (═NH) —C (═NH) O—, etc.), thiocarbonamide (preferably having carbon atoms 1-20 thiocarbonamide, such as CH ₃ N═C (CH ₃ ) S—, or thiourea (preferably a thiourea having 1-20 carbon atoms, such as NH (...) = C (S— ) NH ₂ , CH ₃ N (...) = C (S—) NHCH ₃ , (CH ₃ ) ₂ N—C (S...) N (CH ₃ ) _2, etc.) "..." indicates a coordination bond.

  The ligand X is preferably an acyloxy group, an oxalylene group, a thioacylthio group, an acylaminooxy group, a dithiocarbamate group, a dithiocarbonate group, a trithiocarbonate group, a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate group, A ligand coordinated by a group selected from the group consisting of a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a ligand composed of a halogen atom, carbonyl, 1,3-diketone or thiourea More preferably, the coordination is carried out by a group selected from the group consisting of acyloxy group, acylaminooxy group, dithiocarbamate group, thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, cyano group or arylthio group. Child or halo A ligand consisting of a thione atom, 1,3-diketone or thiourea, particularly preferably coordinated with a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group, an isothiocyanate group, a cyanate group and an isocyanate group. A ligand or a ligand comprising a halogen atom or a 1,3-diketone, most preferably a ligand coordinated by a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group and an isothiocyanate group Or a ligand composed of 1,3-diketone. In addition, when the ligand X contains an alkyl group, an alkenyl group, an alkynyl group, an alkylene group or the like, these may be linear or branched, and may be substituted or unsubstituted. Moreover, when an aryl group, a heterocyclic group, a cycloalkyl group, etc. are included, they may be substituted or unsubstituted, and may be monocyclic or condensed.

・ Counterion CI
CI in the general formula (1) represents a counter ion when a counter ion is necessary to neutralize the charge. In general, whether a dye is a cation or an anion or has a net ionic charge depends on the metal, ligand and substituent in the dye.
The dye of the general formula (1) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the charge of the whole dye of the general formula (1) is electrically neutralized by CI.

When the counter ion CI is a positive counter ion, for example, the counter ion CI is an inorganic or organic ammonium ion (for example, tetraalkylammonium ion, pyridinium ion, etc.), an alkali metal ion, or a proton.
When the counter ion CI is a negative counter ion, for example, the counter ion CI may be an inorganic anion or an organic anion. For example, halogen anions (eg, fluoride ions, chloride ions, bromide ions, iodide ions, etc.), substituted aryl sulfonate ions (eg, p-toluene sulfonate ions, p-chlorobenzene sulfonate ions, etc.), aryl disulfones Acid ion (for example, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion, etc.), alkyl sulfate ion (for example, methyl sulfate ion, etc.), sulfate ion, thiocyanate ion Perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, picrate ion, acetate ion, trifluoromethanesulfonate ion and the like. Furthermore, as the charge balance counter ion, an ionic polymer or another dye having a charge opposite to that of the dye may be used, and a metal complex ion (for example, bisbenzene-1,2-dithiolatonickel (III)) can also be used. is there.

The acidic group (binding group) is the same as that of the dye having the specific adsorption equilibrium constant, and the preferred range is also the same.

Although the specific example of the pigment | dye which has a structure represented by General formula (13) used by this invention is shown below, this invention is not limited to these. In addition, when the pigment | dye in the following specific example contains the ligand which has a proton dissociable group, this ligand may dissociate as needed and may discharge | release a proton.

  The method of synthesizing the dye represented by the general formula (13) can be referred to the method described in Examples below, and can be synthesized by appropriately applying a conventional method based thereon. In addition, J.H. Am. Chem. Soc. 121, 4047 (1999), Can. J. et al. Chem. , 75, 318 (1997), Inorg. Chem. 27, 4007 (1988), etc. and the methods cited in the literature, and the dyes and methods described herein are cited in this specification. Information described in JP 2001-291534 A and WO 2007/091525 can also be referred to, and the dyes and methods described herein are cited in this specification.

  In the dye having the structure of the general formula (13), the maximum absorption wavelength in the solution is preferably in the range of 300 to 1000 nm, more preferably in the range of 350 to 950 nm, and particularly preferably in the range of 370 to 900 nm. .

  In the present invention, the content of the dye represented by the general formula (13) is not particularly limited, but is preferably 0.001 to 1 mmol, and preferably 0.1 to 0.5 mmol with respect to 1 g of the semiconductor fine particles. It is more preferable that By setting it as the said lower limit or more, the sensitization effect in a semiconductor can fully be acquired, and the reduction of the sensitization effect by desorption of a pigment | dye can be suppressed by setting it as the said upper limit or less. In the present invention, two or more dyes represented by the general formula (13) may be used.

  In the present invention, the amount (S) of the dye having the specific adsorption equilibrium constant is preferably adjusted in relation to the amount (R) of the metal complex dye represented by the following general formula (13). Specifically, in terms of molar ratio, S / R is preferably from 0.01 to 1, more preferably from 0.05 to 0.5, and particularly preferably from 0.08 to 0.12. By using in such a range, the pigment | dye which has the said specific adsorption equilibrium constant mentioned later acts functionally and is preferable.

  The difference (Rw−Sw) between the absorption maximum wavelength (Sw) of the dye represented by the general formula (1) and the absorption maximum wavelength (Rw) of the dye represented by the general formula (13) is 150 to 800 nm. Is preferable, and it is more preferable that it is 300-700 nm. By having a maximum absorption wavelength in such a region, it is possible to perform a more efficient photoelectric change by light centered on visible light useful as a solar cell in combination with the dye represented by the general formula (13) described later. It becomes.

The dye having the specific adsorption equilibrium constant is particularly preferably used in combination with the compound represented by the general formula (13) and applied to a photoelectric conversion element as a composite sensitizing dye. By doing so, the effect of the above-described dye having a high equilibrium constant on the titania surface is suitably exhibited, suppressing the access of I ₃ ⁻ and water molecules present in the device to titanium oxide, and the general formula It is thought that the good adsorption state of the metal complex dye represented by (13) is maintained and the photoelectric conversion effect is effectively exhibited. That is, the dye of the general formula (1) works favorably, maintains high photoelectric conversion efficiency, and can realize high durability.

[Charge transfer layer]
A layer made of an electrolyte composition can be applied to the charge transfer layer used in the photoelectric conversion element of this embodiment. As the redox pair, for example, a combination of iodine and iodide (eg, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.), alkyl viologen (eg, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoro) Borate) and its reduced form, a combination of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and its oxidized form, a combination of divalent and trivalent iron complexes (for example, red blood salt and yellow blood salt) Etc. Of these, a combination of iodine and iodide is preferred.
The cation of the iodine salt is preferably a 5-membered or 6-membered nitrogen-containing aromatic cation. In particular, when the compound represented by the general formula (2) is not an iodine salt, it is described in WO95 / 18456, JP-A-8-259543, Electrochemistry, Vol. 65, No. 11, page 923 (1997), etc. It is preferable to use iodine salts such as pyridinium salts, imidazolium salts, and triazolium salts.
The electrolyte composition used for the photoelectric conversion element preferably contains iodine together with the heterocyclic quaternary salt compound. The iodine content is preferably 0.1 to 20% by mass, and more preferably 0.5 to 5% by mass with respect to the entire electrolyte composition.

The electrolyte composition may contain a solvent. The content of the solvent in the electrolyte composition is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less based on the entire composition.
As the solvent, a solvent having a low viscosity and high ion mobility, a high dielectric constant and capable of increasing the effective carrier concentration, or both is preferable because it can exhibit excellent ion conductivity. As such a solvent, carbonate compounds (ethylene carbonate, propylene carbonate, etc.), heterocyclic compounds (3-methyl-2-oxazolidinone, etc.), ether compounds (dioxane, diethyl ether, etc.), chain ethers (ethylene glycol dialkyl ether, Propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.), Polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol , Polypropylene glycol, glycerol, etc.), nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, biscyanoethyl ether, etc.), esters (carboxylic esters, phosphate esters, phosphonate esters, etc.) ), Aprotic polar solvent (dimethyl sulfoxide (DMSO), sulfolane, etc.), water, hydrous electrolyte described in JP-A No. 2002-110262, JP-A No. 2000-36332, JP-A No. 2000-243134, and republication Examples include electrolyte solvents described in WO / 00-54361. These solvents may be used as a mixture of two or more.

  Further, as the electrolyte solvent, an electrochemically inert salt that is in a liquid state at room temperature and / or has a melting point lower than room temperature may be used. For example, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, etc., nitrogen-containing heterocyclic quaternary salt compounds such as imidazolium salts and pyridinium salts, or tetraalkylammonium salts Is mentioned.

  A polymer or an oil gelling agent may be added to the electrolyte composition, or it may be gelled (solidified) by a technique such as polymerization of polyfunctional monomers or a crosslinking reaction of the polymer.

  When the electrolyte composition is gelled by adding a polymer, a compound described in Polymer Electrolyte Reviews-1 and 2 (J.R. MacCallum and CA Vincent, co-edited by ELSEVIER APPLIED SCIENCE) is added. be able to. In this case, it is preferable to use polyacrylonitrile or polyvinylidene fluoride.

  When the electrolyte composition is gelled by adding an oil gelling agent, J.I. Chem. Soc. Japan, Ind. Chem. Soc. , 46779 (1943); Am. Chem. Soc. 111, 5542 (1989); Chem. Soc. Chem. Commun. , 390 (1993), Angew. Chem. Int. Ed. Engl. , 35, 1949 (1996), Chem. Lett. , 885 (1996), J. Am. Chem. Soc. Chem. Commun. , 545, (1997) and the like, and a compound having an amide structure is preferably used.

  When gelling the electrolyte composition by polymerization of polyfunctional monomers, prepare a solution from the polyfunctional monomers, polymerization initiator, electrolyte and solvent, and use methods such as casting, coating, dipping, and impregnation. A method in which a sol-like electrolyte layer is formed on an electrode carrying a dye and then gelled by radical polymerization of a polyfunctional monomer is preferred. The polyfunctional monomers are preferably compounds having two or more ethylenically unsaturated groups, such as divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol Ethylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate and the like are preferable.

The electrolyte composition, the metal iodide (LiI, NaI, KI, CsI , CaI 2 , etc.), a metal bromide (LiBr, NaBr, KBr, CsBr , CaBr 2 , etc.), quaternary ammonium bromine salt (tetraalkylammonium bromide, Pyridinium bromide, etc.), metal complexes (ferrocyanate-ferricyanate, ferrocene-ferricinium ion, etc.), sulfur compounds (sodium polysulfide, alkylthiol-alkyl disulfides, etc.), viologen dye, hydroquinone-quinone, etc. You can do it. These may be used as a mixture.

Further, in the present invention, J.P. Am. Ceram. Soc. 80, (12), 3157-3171 (1997), and basic compounds such as 2-picoline and 2,6-lutidine may be added. A preferable concentration range in the case of adding a basic compound is 0.05 to 2M.
Further, as the electrolyte, a charge transport layer containing a hole conductor material may be used. As the hole conductor material, 9,9′-spirobifluorene derivative or the like can be used.

  As a structure of the electrochemical element, a conductive support (electrode layer), a photoelectric conversion layer (photosensitive layer and charge transfer layer), a hole transport layer, a conductive layer, and a counter electrode layer can be sequentially laminated. A hole transport material that functions as a p-type semiconductor can be used as a hole transport layer. As a preferred hole transport layer, for example, an inorganic or organic hole transport material can be used. Examples of the inorganic hole transport material include CuI, CuO, and NiO. Examples of the organic hole transport material include high molecular weight materials and low molecular weight materials, and examples of the high molecular weight materials include polyvinyl carbazole, polyamine, and organic polysilane. Moreover, as a low molecular weight thing, a triphenylamine derivative, a stilbene derivative, a hydrazone derivative, a phenamine derivative etc. are mentioned, for example. Among these, organic polysilanes are preferable because, unlike conventional carbon-based polymers, σ electrons delocalized along the main chain Si contribute to photoconductivity and have high hole mobility (Phys. Rev.). B, 35, 2818 (1987)).

The conductive layer is not particularly limited as long as it has good conductivity, and examples thereof include inorganic conductive materials, organic conductive materials, conductive polymers, and intermolecular charge transfer complexes. Among them, an intermolecular charge transfer complex formed from a donor material and an acceptor material is preferable. Among these, what was formed from the organic donor and the organic acceptor can be used preferably. The donor material is preferably a material rich in electrons in the molecular structure. For example, organic donor materials include those having a substituted or unsubstituted amine group, hydroxyl group, ether group, selenium or sulfur atom in the π-electron system of the molecule, specifically, phenylamine-based, triphenylmethane , Carbazole, phenol, and tetrathiafulvalene materials. As the acceptor material, those lacking electrons in the molecular structure are preferable. For example, organic acceptor materials include fullerenes, those having a substituent such as a nitro group, a cyano group, a carboxyl group or a halogen group in the π-electron system of the molecule, specifically, PCBM, benzoquinone, naphthoquinone, etc. Quinone, fluoroenone, chloranil, bromanyl, tetracyanoquinodimethane, tetracyanoethylene and the like.
The thickness of the conductive layer is not particularly limited, but is preferably such that the porous layer can be completely filled.

[Conductive support]
As the conductive support, there can be used a glass or a polymer material having a conductive film layer on the surface, such as a metal that is conductive in the support itself. It is preferable that the conductive support is substantially transparent. Substantially transparent means that the light transmittance is 10% or more, preferably 50% or more, particularly preferably 80% or more. As the conductive support, a glass or polymer material coated with a conductive metal oxide can be used. The coating amount of the conductive metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of the support of glass or polymer material. When a transparent conductive support is used, light is preferably incident from the support side. Examples of polymer materials that are preferably used include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), Examples include polyarylate (PAR), polysulfone (PSF), polyester sulfone (PES), polyetherimide (PEI), cyclic polyolefin, and brominated phenoxy. On the conductive support, the surface may be provided with a light management function. For example, an antireflection film in which high refractive films and low refractive index oxide films described in JP-A-2003-123859 are alternately laminated, The light guide function described in Open 2002-260746 is raised.
In addition to this, a metal support can also be preferably used. Examples thereof include titanium, aluminum, copper, nickel, iron, stainless steel, and copper. These metals may be alloys. More preferably, titanium, aluminum, and copper are preferable, and titanium and aluminum are particularly preferable.

It is preferable that the conductive support has a function of blocking ultraviolet light. For example, a method in which a fluorescent material capable of changing ultraviolet light into visible light is present in the transparent support or on the surface of the transparent support, and a method using an ultraviolet absorber are also included.
A function described in JP-A No. 11-250944 may be further provided on the conductive support.

Preferred conductive films include metals (eg, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.) ).
The thickness of the conductive film layer is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm.
The lower the surface resistance of the conductive support, the better. The range of the surface resistance is preferably 50 Ω / cm ² or less, more preferably 10 Ω / cm ² or less. Although there is no restriction | limiting in particular in this lower limit, Usually, it is about 0.1 ohm / cm < ² >.

Since the resistance value of the conductive film increases as the cell area increases, a collecting electrode may be disposed. A gas barrier film and / or an ion diffusion prevention film may be disposed between the support and the transparent conductive film. As the gas barrier layer, a resin film or an inorganic film can be used.
Moreover, you may provide a transparent electrode and a porous semiconductor electrode photocatalyst content layer. The transparent conductive layer may have a laminated structure, and as a preferable method, for example, FTO can be laminated on ITO.

[Semiconductor fine particles]
As the semiconductor fine particles, metal chalcogenides (for example, oxides, sulfides, selenides, etc.) or perovskite fine particles are preferably used. Preferred examples of the metal chalcogenide include titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum oxide, cadmium sulfide, cadmium selenide, and the like. . Preferred perovskites include strontium titanate and calcium titanate. Of these, titanium oxide, zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

There are n-type semiconductors in which the carriers involved in the conduction are electrons and p-types in which the carriers are holes. The use of the n-type is preferable in terms of conversion efficiency. In an n-type semiconductor, in addition to an intrinsic semiconductor (or an intrinsic semiconductor) having no impurity level and having the same carrier concentration due to conduction band electrons and valence band holes, the electron carrier concentration is reduced by structural defects derived from impurities. There are high n-type semiconductors. The n-type inorganic semiconductor preferably used in the present invention is TiO ₂ , TiSrO ₃ , ZnO, Nb ₂ O ₃ , SnO ₂ , WO ₃ , Si, CdS, CdSe, V ₂ O ₅ , ZnS, ZnSe, SnSe, KTaO. ₃ , FeS ₂ , PbS, InP, GaAs, CuInS ₂ , CuInSe ₂ and the like. Of these, the most preferred n-type semiconductors are TiO ₂ , ZnO, SnO ₂ , WO ₃ , and Nb ₂ O ₃ . A semiconductor material in which a plurality of these semiconductors are combined is also preferably used.

  For the purpose of keeping the viscosity of the semiconductor fine particle dispersion high, it is preferable that the average particle size of the primary particles is 2 nm to 50 nm, and the average primary particle size is 2 nm to 30 nm. More preferably, it is a fine particle. Two or more kinds of fine particles having different particle size distributions may be mixed. In this case, the average size of the small particles is preferably 5 nm or less. In addition, for the purpose of scattering incident light and improving the light capture rate, large particles having an average particle size exceeding 50 nm can be added to the ultrafine particles at a low content, or another layer can be applied. In this case, the content of the large particles is preferably 50% or less, more preferably 20% or less of the mass of particles having an average particle size of 50 nm or less. The average particle size of the large particles added and mixed for the above purpose is preferably 100 nm or more, and more preferably 250 nm or more.

By using large particles for light scattering, the haze ratio is preferably 60% or more. The haze ratio is expressed by (diffuse transmittance) / (total light transmittance).
As a method for producing the semiconductor fine particles, the gel-sol method described in Sakuo Sakuo's “Science of Sol-Gel Method”, Agne Jofu Co., Ltd. (1998) and the like is preferable. Also preferred is a method of producing an oxide by hydrolyzing a chloride developed by Degussa in an oxyhydrogen salt. When the semiconductor fine particles are titanium oxide, the above sol-gel method, gel-sol method, and high-temperature hydrolysis method in oxyhydrogen salt of chloride are preferred, but Kiyoshi Manabu's “Titanium oxide properties and applied technology” The sulfuric acid method and the chlorine method described in Gihodo Publishing (1997) can also be used. Further, as the sol-gel method, the method described in Journal of American Ceramic Society, Vol. 80, No. 12, 3157-3171 (1997), or the chemistry of Burnside et al. The method described in Materials, Vol. 10, No. 9, pages 2419-2425 is also preferable.

  In addition to this, as a method for producing semiconductor fine particles, for example, as a method for producing titania nanoparticles, preferably, a method by flame hydrolysis of titanium tetrachloride, a combustion method of titanium tetrachloride, hydrolysis of a stable chalcogenide complex, orthotitanic acid Of semiconductor, forming semiconductor fine particles from soluble and insoluble parts, then dissolving and removing soluble parts, hydrothermal synthesis of peroxide aqueous solution, or production of core / shell structured titanium oxide fine particles by sol-gel method A method is mentioned.

Examples of the crystal structure of titania include anatase type, brookite type, and rutile type, and anatase type and brookite type are preferable.
Titania nanotubes, nanowires, and nanorods may be mixed with titania fine particles.

  Titania may be doped with a nonmetallic element or the like. In addition to the dopant as an additive to titania, an additive may be used on the surface to improve the necking or to prevent reverse electron transfer. Examples of preferred additives include ITO, SnO particles, whiskers, fibrous graphite / carbon nanotubes, zinc oxide necking binders, fibrous materials such as cellulose, metals, organic silicon, dodecylbenzenesulfonic acid, silane compounds, etc. Examples thereof include a mobile binding molecule and a potential gradient dendrimer.

  For the purpose of removing surface defects on titania, titania may be acid-base or redox treated before dye adsorption. Etching, oxidation treatment, hydrogen peroxide treatment, dehydrogenation treatment, UV-ozone, oxygen plasma, or the like may be used.

[Preparation of semiconductor fine particle dispersion and preparation of semiconductor fine particle layer]
In the present invention, the semiconductor fine particle dispersion having a solid content other than the semiconductor fine particles of 10% by mass or less of the entire semiconductor fine particle dispersion is coated on the conductive support and heated to a suitable level. Quality semiconductor fine particle coating layer can be obtained.
In addition to the sol-gel method described above, a method of preparing a semiconductor fine particle dispersion is a method of depositing fine particles in a solvent and using them as they are when synthesizing a semiconductor. Ultrafine particles are irradiated with ultrasonic waves. Or a method of mechanically pulverizing and grinding using a mill or a mortar. As the dispersion solvent, water and / or various organic solvents can be used. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, citronellol and terpineol, ketones such as acetone, esters such as ethyl acetate, dichloromethane, acetonitrile and the like.
At the time of dispersion, a small amount of, for example, a polymer such as polyethylene glycol, hydroxyethyl cellulose, carboxymethyl cellulose, a surfactant, an acid, or a chelating agent may be used as a dispersion aid. However, most of these dispersing aids are preferably removed by a filtration method, a method using a separation membrane, a centrifugal method or the like before the step of forming a film on a conductive support. In the semiconductor fine particle dispersion, the solid content other than the semiconductor fine particles can be 10% by mass or less of the total dispersion. This concentration is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. More preferably, it is 0.5% or less, and particularly preferably 0.2%. That is, in the semiconductor fine particle dispersion, the solid content other than the solvent and the semiconductor fine particles can be 10% by mass or less of the entire semiconductor fine dispersion. It is preferable to consist essentially of semiconductor fine particles and a dispersion solvent.
If the viscosity of the semiconductor fine particle dispersion is too high, the dispersion may aggregate and cannot be formed into a film. Conversely, if the viscosity of the semiconductor fine particle dispersion is too low, the liquid may flow and be unable to form a film. is there. Therefore, the viscosity of the dispersion is preferably 10 to 300 N · s / m ² at 25 ° C. More preferably, it is 50 to 200 N · s / m ² at 25 ° C.

As a method for applying the semiconductor fine particle dispersion, a roller method, a dip method, or the like can be used as an application method. Moreover, an air knife method, a blade method, etc. can be used as a metering method. Further, the application system method and the metering system method can be made the same part. The wire bar method disclosed in Japanese Patent Publication No. 58-4589, the slide hopper method described in US Pat. The method and the curtain method are preferable. It is also preferable to apply by a spin method or a spray method using a general-purpose machine. As the wet printing method, intaglio, rubber plate, screen printing and the like are preferred, including the three major printing methods of letterpress, offset and gravure. From these, a preferred film forming method is selected according to the liquid viscosity and the wet thickness. Further, since the semiconductor fine particle dispersion has a high viscosity and has a viscous property, it may have a strong cohesive force and may not be well adapted to the support during coating. In such a case, by performing cleaning and hydrophilization of the surface by UV ozone treatment, the binding force between the applied semiconductor fine particle dispersion and the surface of the conductive support increases, and the semiconductor fine particle dispersion can be easily applied.
The preferred thickness of the entire semiconductor fine particle layer is 0.1 to 100 μm. The thickness of the semiconductor fine particle layer is further preferably 1 to 30 μm, and more preferably 2 to 25 μm. The amount of the semiconductor fine particles supported per 1 m ² of the support is preferably 0.5 g to 400 g, and more preferably 5 to 100 g.

The applied semiconductor fine particle layer is subjected to heat treatment in order to enhance the electronic contact between the semiconductor fine particles and to improve the adhesion to the support and to dry the applied semiconductor fine particle dispersion. . By this heat treatment, a porous semiconductor fine particle layer can be formed. In addition, the semiconductor fine particle layer may be formed by a known method as appropriate according to the characteristics and application of the member. For example, the materials, preparation methods, and manufacturing methods described in Japanese Patent Application Laid-Open No. 2001-291534 can be referred to, and are cited in this specification.
The coating amount of the semiconductor fine particles per 1 m ² of the support is preferably 0.5 to 500 g, more preferably 5 to 100 g.

In order to adsorb the dye to the semiconductor fine particles, it is preferable to immerse the well-dried semiconductor fine particles in a dye adsorbing dye solution composed of a solution and a dye for a long time. The solution used for the dye solution for dye adsorption can be used without particular limitation as long as the solution can dissolve the dye. For example, ethanol, methanol, isopropanol, toluene, t-butanol, acetonitrile, acetone, n-butanol and the like can be used. Among these, ethanol and toluene can be preferably used.
You may heat the pigment | dye solution for pigment | dye adsorption which consists of a solution and a pigment | dye to 50 to 100 degreeC as needed. The adsorption of the dye may be performed before or after application of the semiconductor fine particles. Further, the semiconductor fine particles and the dye may be applied and adsorbed simultaneously. Unadsorbed dye is removed by washing. When baking a coating film, it is preferable to adsorb | suck a pigment | dye after baking. It is particularly preferable that the dye is quickly adsorbed after the baking and before water adsorbs on the surface of the coating film. The dye to be mixed is selected so as to make the wavelength range of photoelectric conversion as wide as possible. When mixing the dyes, it is preferable to prepare a dye solution for dye adsorption by dissolving all the dyes.

The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, particularly preferably 0.1 to 10 mmol, per 1 m ² of the support. In this case, it is preferable that the usage-amount of a pigment | dye shall be 5 mol% or more.
Further, the adsorption amount of the dye to the semiconductor fine particles is preferably 0.001 to 1 mmol, more preferably 0.1 to 0.5 mmol, with respect to 1 g of the semiconductor fine particles. By using such a dye amount, a sensitizing effect in a semiconductor can be sufficiently obtained.

[Counter electrode]
The counter electrode (counter electrode) serves as the positive electrode of the photoelectrochemical cell. The counter electrode is usually synonymous with the conductive support described above, but the support is not necessarily required in a configuration in which the strength is sufficiently maintained. However, having a support is advantageous in terms of hermeticity. Examples of the material for the counter electrode include platinum, carbon, conductive polymer, and the like. Preferable examples include platinum, carbon, and conductive polymer.

As the structure of the counter electrode, a structure having a high current collecting effect is preferable. Preferable examples include JP-A-10-505192.
As the light receiving electrode, a composite electrode such as titanium oxide and tin oxide (TiO ₂ / SnO ₂ ) may be used. Examples of mixed electrodes other than titania include JP-A Nos. 2001-185243 and 2003-282164.

  The element may have a structure in which a first electrode layer, a first photoelectric conversion layer, a conductive layer, a second photoelectric conversion layer, and a second electrode layer are sequentially stacked. In this case, the dyes used for the first photoelectric conversion layer and the second photoelectric conversion layer may be the same or different, and when they are different, it is preferable that the absorption spectra are different. In addition, structures and members that are applied to this type of electrochemical element can be applied as appropriate.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these.

(Example 1 and Comparative Example 1)
The photoelectric conversion element shown in FIG. 1 was produced as follows.
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts.
Next, 32 g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) is mixed with 100 ml of a mixed solvent of water and acetonitrile having a volume ratio of 4: 1, and a rotating / revolving mixing conditioner is prepared. The resulting mixture was uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion. This dispersion was applied to a transparent conductive film and heated at 500 ° C. to produce a light receiving electrode.
Thereafter, similarly, a dispersion containing 40:60 (mass ratio) of silica particles and rutile-type titanium oxide is prepared, and this dispersion is applied to the light receiving electrode and heated at 500 ° C. to form an insulating porous material. Formed body. Next, a carbon electrode was formed as a counter electrode.

Next, the glass substrate on which the insulating porous body was formed was immersed in an ethanol solution (3 × 10 ⁻⁴ mol / l) of a sensitizing dye described in Table 1 below for 48 hours. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² . As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / l) and iodine (0.1 mol / l) was used.

(Measurement method of dye adsorption power (g / L))
TiO ₂ nanoparticle powder (trade name P-25, manufactured by Nippon Aerosil Co., Ltd., average particle) in a dye solution (solvent: solvent in which the dye is soluble (solvent described below) such as ethanol and toluene) in a dye solution having a known concentration 30 nm in diameter, surface area of about 50 m ² / g), adsorbed in the dark at 40 ° C., and the amount of the dye remaining in the supernatant was determined by HPLC (apparatus: Shimadzu Corporation, trade name controller: SCL-10AVP, Chromatopack: C-R7A plus, Detector: SPD-10ATVP, Degaster: DGU-12A, Pump: LC-10ATVP, Column oven: CTO-10ATVP (HPLC is made up of a combination of multiple machines) To calculate the amount of dye adsorbed to TiO ₂ and the equilibrium concentration, and create Langmuir-Plot. did. The adsorption equilibrium constant was calculated from this Langmuir-Plot according to the following equation.
<Langmuire-Plot>
1 / W = 1 / Ws + 1 / aWs × 1 / C

(Measurement of maximum absorption wavelength of dye)
The maximum absorption wavelength of the dye used was measured. The results are shown in Table A. The measurement is performed with a spectrophotometer (U-4100 (trade name), manufactured by Hitachi High-Tech), and the solution is THF: ethanol (measurement of photoelectric conversion efficiency).
Simulated sunlight containing no ultraviolet rays was generated by passing the light of a 500 W xenon lamp (manufactured by Ushio) through an AM1.5G filter (manufactured by Oriel) and a sharp cut filter (KenkoL-42, trade name). The intensity of this light was 89 mW / cm ² . The produced photoelectric conversion element was irradiated with this light, and the generated electricity was measured with a current-voltage measuring device (Caseley 238 type, trade name). The results of measuring the conversion efficiency of the photoelectrochemical cell thus obtained are shown in Table 1 below. The results were evaluated as follows.
AA: Conversion efficiency of 2.5% or more A: 2.0% or more and less than 2.5% B: 1.5% or more and less than 2.0% C: Less than 1.5%
(durability)
The rate of decrease in conversion efficiency after 3 hours of operation was evaluated and distinguished as follows.
AA: conversion efficiency decrease rate of less than 8% A: conversion efficiency decrease rate of 5% or more and less than 8% B: conversion efficiency decrease rate of 2% or more and less than 5% C: conversion efficiency The rate of decrease is less than 2%

化合物Ｂ−１：Sayama et al.,Chem.Lett.,753(1998)に記載の色素
化合物Ｂ−２：T.Horiuchi et.al., JACS,126(39),12218(2004)に記載の色素
化合物B-3：K. Hara et. al. Chem. Commun. 569, 2001
化合物B-5:K. Sayama et. al. Chem. Commun. 1173, 2000

Compound B-1: Dye compound described in Sayama et al., Chem. Lett., 753 (1998) B-2: described in T. Horiuchi et.al., JACS, 126 (39), 12218 (2004) Dye compound B-3: K. Hara et. Al. Chem. Commun. 569, 2001
Compound B-5: K. Sayama et. Al. Chem. Commun. 1173, 2000

  As shown in Table 1, the dye of the comparative example had a small adsorption equilibrium constant and was inferior in photoelectric conversion efficiency and durability when used as a photoelectric conversion element. On the other hand, an element produced using the dye of the present invention has an adsorption equilibrium constant of the organic sensitizing dye applied thereto in a desired range, shows a high conversion efficiency, and has a high durability. Showed sex.

(Example 2 and Comparative Example 2)
For Example 1 and Comparative Example 1 above, photoelectric conversion elements to which the metal complex dyes shown in Table 2 were further applied as the dyes to be applied were prepared and evaluated in the same manner. In addition, the addition amount of the pigment | dye was applied as an amount shown in the table | surface with respect to the surface area of a titania.

表２に示されているように、比較例の色素は金属錯体色素と組み合わせてみても光電変換素子としたときに光電変換効率及び耐久性について劣るものであった。これに対して本発明の色素を用いて作製された素子は、そこに適用される有機増感色素の吸着平衡定数がいずれも所望の範囲にあり、高い変換効率と高い耐久性とを両立して実現し、特に特定の金属錯体との併用により一層効果が高まることが分かる。

As shown in Table 2, the dye of the comparative example was inferior in photoelectric conversion efficiency and durability when used as a photoelectric conversion element even when combined with a metal complex dye. On the other hand, in the element produced using the dye of the present invention, the adsorption equilibrium constant of the organic sensitizing dye applied thereto is in a desired range, and both high conversion efficiency and high durability are achieved. In particular, it can be seen that the combined use with a specific metal complex further enhances the effect.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Photoconductor layer 21 Dye 22 Semiconductor fine particle 3 Charge transfer body layer 4 Counter electrode 5 Photosensitive electrode 6 Circuit 10 Photoelectric conversion element 100 Photoelectrochemical cell

Claims (13)

  A photoelectric conversion element comprising a photoreceptor layer having an organic sensitizing dye and semiconductor fine particles, wherein the organic sensitizing dye has an adsorption equilibrium constant for titanium oxide in a solvent of 300 g / L or more and 10,000 g / L. The photoelectric conversion element characterized by applying the following pigment | dyes. The said organic sensitizing dye is represented by following General formula (1), The photoelectric conversion element of Claim 1 characterized by the above-mentioned.
Dye- (A) _n1 ... General formula (1)
[Dye represents a dye molecule, A represents an acidic group, and n1 represents the above integer. ]   The photoelectric conversion element according to claim 1, wherein the organic sensitizing dye is a donor-acceptor type dye. The said organic pigment | dye is represented by general formula (1A), The photoelectric conversion element of any one of Claims 1-3 characterized by the above-mentioned.

[In General Formula (1A), R represents a hydrogen atom or a substituent. R may form a ring structure represented by X ¹ , X ² , and / or X ³ . X ¹ , X ² , and X ³ may be the same or different. In addition, although acidic group A is not shown in a formula, it has one or more acidic groups A in a molecule | numerator. ] The said organic sensitizing dye is shown by following General formula (2) or (4), The photoelectric conversion element in any one of Claims 1-4 characterized by the above-mentioned.

[In General Formula (2), X represents a nonmetallic atom group required in order to couple | bond with a benzene ring and to form a nitrogen-containing 4-7 membered ring. R ¹ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded with a carbon atom. R ^{2 to} R ⁹ represent a hydrogen atom or a substituent, and at least one of the substituents represents a dye residue represented by the general formula (3). In General Formula (3), R ¹⁰ , R ¹¹ , and R ¹³ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. r represents an integer of 0 or more. The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ¹² represents a group having at least one acidic group or an acidic nucleus. ]
[In General Formula (4), A represents an atomic group required in order to form a ring with a carbon-nitrogen bond. Y ¹ and Y ² each represent an acidic group, and when both represent an acidic group, they may be the same or different from each other. When only one represents an acidic group, the other represents an electron withdrawing group. Represents. D represents a pigment residue, and n represents an integer of 1 or more. L represents a single bond or a divalent linking group. Y ³ represents an acidic group. ] The said organic sensitizing dye is shown by following General formula (5), The photoelectric conversion element in any one of Claims 1-5 characterized by the above-mentioned.

[In the general formula ^{(5), R 1 ~R 3} , R 5, R 6, R 8 ~R 13 is, ^R 1 ^{to R} 3, respectively, in the general formula (2) and the general formula ^{(3), R 5, R 6} , which is synonymous with R ^{8 to} R ¹³ . ]   The photoelectric conversion element according to claim 1, wherein the organic sensitizing dye is a dye having an adsorption equilibrium constant with respect to the titanium oxide of 500 g / L or more and 7,000 g / L or less. The photoelectric conversion element according to any one of claims 1 to 7, wherein a solvent for adsorbing the organic sensitizing dye is selected from the group consisting of the following (a) to (l).
(A) Carbonate esters For example, ethylene carbonate, propylene carbonate 50, vinylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate and the like are preferable.
(B) Lactones For example, γ-butyrolactone, γ-valerolactone, γ-caprolactone, crotolactone, γ-caprolactone, δ-valerolactone and the like are preferable.
(C) Ethers For example, ethyl ether, 1,2-dimethoxyethane, diethoxyethane, trimethoxymethane, ethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane and the like are preferable.
(D) Alcohols For example, methanol, ethanol, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether and the like are preferable.
(E) Glycols For example, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin and the like are preferable.
(F) Glycol ethers For example, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether and the like are preferable.
(G) Tetrahydrofurans For example, tetrahydrofuran, 2-methyltetrahydrofuran and the like are preferable.
(H) Nitriles For example, acetonitrile, glutarodinitrile, propionitrile, methoxyacetonitrile, benzonitrile and the like are preferable.
(I) Carboxylic acid esters For example, methyl formate, methyl acetate, ethyl acetate, methyl propionate and the like are preferable.
(J) Phosphoric acid triesters For example, trimethyl phosphate and triethyl phosphate are preferable.
(K) heterocyclic compounds such as N-methylpyrrolidone, 4-methyl-1,3-dioxane, 2-methyl-1,3-dioxolane, 3-methyl-2-oxazolidinone, 1,3-propane sultone, sulfolane Etc. are preferred.
(L) Others Aprotic organic solvents such as dimethyl sulfoxide, formamide, N, N-dimethylformamide, nitromethane, JP-A-2001-237000 (P2001-237000A). The organic sensitizing dye is contained in a range of 5 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² with respect to a unit surface area of the semiconductor material to be adsorbed. Item 1. The photoelectric conversion element according to item 1.   The photoelectric conversion element according to any one of claims 1 to 9, wherein a composite sensitizing dye in which the organic sensitizing dye and a metal complex sensitizing dye are combined is used. The photoelectric conversion element according to claim 10, wherein the metal complex sensitizing dye is represented by the following general formula (13).

Mz (LL ¹¹ ) m ₁₁ (LL ¹² ) m ₁₂ (X) m ₁₃ · DI General formula (13)

[In General Formula (13), Mz represents a metal atom, LL ¹¹ is a bidentate or tridentate ligand represented by the following General Formula (14), and LL ¹² is represented by the following General Formula (15): The bidentate or tridentate ligand represented.
X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, A monodentate or bidentate ligand coordinated by a group selected from the group consisting of an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a halogen atom Represents a monodentate or bidentate ligand consisting of carbonyl, dialkyl ketone, 1,3-diketone, carbonamide, thiocarbonamide or thiourea.
m11 represents an integer of 0 to 3, when m11 is 2 or more, ^{LL 11} may be the same or different. m12 represents an integer of 0 to 3, when m12 is 2, ^{LL 12} may be the same or different. However, at least one of m11 and m12 is an integer of 1 or more.
m13 represents an integer of 0 to 2, and when m13 is 2, Xs may be the same or different, and Xs may be linked together.
DI represents a counter ion in the general formula (13) when a counter ion is necessary to neutralize the charge. ]

[In General Formula (14), R ¹⁰¹ and R ¹⁰² each independently represent a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group, a phosphoryl group, or a phosphonyl group. R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent, and R ¹⁰⁵ and R ¹⁰⁶ each independently represent an aryl group or a heterocyclic group. d1 and d2 each represents an integer of 0 or more.
L ¹ and L ² are each independently a substituted or unsubstituted ethenylene group and / or ethynylene group, and are conjugated to a pyridine ring to which L ¹ and L ² are bonded.
a1 and a2 each independently represent an integer of 0 to 3, R ¹⁰¹ may be the same or different when a1 is 2 or more, and R ¹⁰² may be the same or different when a2 is 2 or more, b1 And b2 each independently represents an integer of 0 to 3. When b1 is 2 or more, R ¹⁰³ may be the same or different, R ¹⁰³ may be linked to each other to form a ring, and when b2 is 2 or more, R ¹⁰⁴ may be the same or different. ¹⁰⁴ may be connected to each other to form a ring. When b1 and b2 are both 1 or ^more, may be linked to form a ring ^{R 103} and ^{R 104} are. d3 is an integer of 0 or more. ]

[In the general formula (15), Za, Zb and Zc each independently represent a non-metallic atom group capable of forming a 5- or 6-membered ring, and may each independently have an acidic group. c represents 0 or 1; ]   A photoelectrochemical cell comprising the photoelectric conversion device according to claim 1.   An organic sensitizing dye for a photoelectric conversion element, having an adsorption equilibrium constant for titanium oxide in a solvent of 300 g / L or more and 10,000 g / L or less.

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