JP5620315B2 - Photoelectric conversion element and photoelectrochemical cell - Google Patents

Description

  The present invention relates to a photoelectric conversion element and a photoelectrochemical cell having high conversion efficiency and excellent durability.

  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.

Patent Document 1 describes a dye-sensitized photoelectric conversion element using semiconductor fine particles sensitized with a ruthenium complex dye by applying this technique. However, although conventional ruthenium complex dyes can be photoelectrically converted using visible light, they hardly absorb infrared light having a wavelength longer than 700 nm, and thus have a problem of low photoelectric conversion ability in the infrared region.
In view of this, a proposal has been made to provide a photoelectric conversion element having a high conversion efficiency by using two or more dyes capable of absorbing light in different wavelength regions (see Patent Document 2, for example).
By the way, the photoelectric conversion element is required to have high initial conversion efficiency, low decrease in conversion efficiency even after use, and excellent durability. However, in terms of durability, the photoelectric conversion element described in Patent Document 2 is not sufficient.
Therefore, a photoelectric conversion element and a photoelectrochemical cell having high conversion efficiency and excellent durability are required.

US Pat. No. 5,463,057 JP 2000-268892 A

  An object of the present invention is to provide a photoelectric conversion element and a photoelectrochemical cell having high photoelectric conversion efficiency and excellent durability.

As a result of intensive studies, the present inventors have obtained a photosensitive member having a porous semiconductor fine particle layer adsorbed in combination with a dye having a specific structure (dye compound) on a conductive support, a charge transfer body, and It has been found that a photoelectric conversion element having a laminated structure including a counter electrode and a photoelectrochemical cell using the same have high conversion efficiency and excellent durability. The present invention has been made based on this finding.
The object of the present invention has been achieved by the following means.

［一般式（１）において、Ｑは４価のベンゼン環基を表し、Ｘ^１ およびＸ^２はそれぞれ独立にＣＲ^１Ｒ^２を表す。ここでＲ^１ およびＲ^２はそれぞれ独立に脂肪族基を表す。ＲおよびＲ’はそれぞれ独立に脂肪族基を表す。Ｐ^１ およびＰ^２はそれぞれ独立に、下記一般式（８）で表される基を表す。Ｗ^１は電荷を中和させるのに必要な場合の対イオンを表す。］

［一般式（８）において、Ｖ ^１ は、カルボキシ基もしくはその塩、または２つのＶ ^１ が互いに結合してベンゼン環を形成する基を表す。ｎは０〜２の整数を表し、ｎが２の場合は、Ｖ ^１ は同じでも異なっていてもよい。
ＹはＣ(Ｒ ^ｂ )Ｒ ^ｃ を表す。Ｒ ^ｂ およびＲ ^ｃ は脂肪族基を表し、同一でも異なっていてもよい。
Ｚは脂肪族基を表し、カルボキシ基または４−カルボキシフェニル基で置換されていてもよい。
Ｒ ^６ およびＲ ^８ はそれぞれ独立に、水素原子または脂肪族基を表す。
Ｒ ^７ は酸素原子、または、下記一般式（１２）〜（１４）のいずれかで表される基を表す。］

［一般式（１２）〜（１４）において、Ｒｆは水素原子または脂肪族基を表す。］

Ｍ（ＬＬ^１）ｍ_１（ＬＬ^２）ｍ_２（Ｘ）ｍ_３・ＣＩ 一般式（２）

［一般式（２）において、ＭはＲｕを表し、ＬＬ^１は下記一般式（５−３）で表される２座の配位子を表し、ＬＬ^２は下記一般式（４）で表される２座の配位子を表す。
Ｘはチオシアネート基、イソチオシアネート基、シアネート基およびイソシアネート基からなる群から選ばれた基で配位する１座の配位子を表す。
ｍ_１ は１を表す。ｍ_２ は１を表す。
ｍ_３ は２を表す。
ＣＩは一般式（２）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（５−３）において、Ｒ^９ およびＲ^１０はそれぞれ独立に、カルボキシ基、スルホ基、ヒドロキシ基、ヒドロキサム酸基、ホスホリル基もしくはホスホニル基またはこれらの塩を表す。Ｒ^１１ およびＲ^１２はそれぞれ独立に置換基を表す。ａ１およびａ２は０を表し、ｂ１およびｂ２は０を表す。ｎは１を表す。Ｒ ^５３ およびＲ ^５４ はアルキニル基またはアリール基を表す。］

［一般式（４）において、Ｚａ、ＺｂおよびＺｃはそれぞれ独立に、ピリジン環を形成しうる非金属原子群を表し、それぞれ独立にカルボキシ基およびその塩から選択される酸性基を有していてもよい。ｃは０を表す。］
<1> A photoelectric conversion element having a laminated structure including a photoconductor having a semiconductor fine particle layer having a dye adsorbed on a conductive support, a charge transfer body, and a counter electrode, wherein the dye is represented by the following general formula (1) A photoelectric conversion device comprising at least one dye comprising a compound represented by formula (1) and at least one dye comprising a compound represented by the following general formula (2).

[In the general formula (1), Q and Table tetravalent benzene ring group, a C ^R 1 ^{R 2 X 1} and X ² are each independently. Here, R ¹ and R ² each independently represents an aliphatic group . R and R ′ each independently represents an aliphatic group . P ¹ and P ² each independently represent a group represented by the following general formula (8) . W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formula (8), V ¹ represents a carboxy group or a salt thereof, or a group in which two V ¹ are bonded to each other to form a benzene ring. n represents an integer of 0 to 2, and when n is 2, V ¹ may be the same or different.
Y represents C (R ^b ) R ^c . R ^b and R ^c represent an aliphatic group and may be the same or different.
Z represents an aliphatic group and may be substituted with a carboxy group or a 4-carboxyphenyl group.
R ⁶ and R ⁸ each independently represents a hydrogen atom or an aliphatic group.
R ⁷ represents an oxygen atom or a group represented by any one of the following general formulas (12) to (14). ]

[In General Formulas (12) to (14), Rf represents a hydrogen atom or an aliphatic group. ]

M (LL ¹ ) m ₁ (LL ² ) m ₂ (X) m ₃ · CI General formula (2)

[In one general formula (2), M represents Ru, LL ¹ represents a bidentate ligand shown by the following formula (5-3), LL ² in the following general formula (4) Table Represents a bidentate ligand.
X represents a Chi Oshianeto group, isothiocyanate group, ligand of monodentate coordinating with a group selected from cyanate group and an isocyanate group or Ranaru group.
m ₁ represents 1 . m ₂ represents 1 .
m ₃ represents 2 .
CI represents a counter ion in the general formula ( 2 ) when a counter ion is necessary to neutralize the charge. ]

[And have contact with one general formula (5-3), each ^{R 9} and ^{R 10} are independently carboxy sheet group, sul ho group, hydroxy sheet group, hydroxamic acid group, a phosphoryl group properly the phosphonyl group or their Represents the salt. R ¹¹ and ^{R 12} is to display the substituents independently. a 1 and a2 will table a 0, b 1 and b2 are to table a 0. n is to Table 1. R ⁵³ and R ⁵⁴ represent an alkynyl group or an aryl group. ]

[In the general formula (4), Za, are each Zb and Zc independently represents a non-metallic atomic group which can form a pyridine ring, having acidic groups selected independently carboxy group and a salt thereof It may be. c represents 0 . ]

［一般式（１０）において、Ｖ^１、ｎ、ＺおよびＹは、前記一般式（８）におけるものと同義である。］
The photoelectric conversion device according to <1> which is characterized by being represented by <2> before Symbol one general formula group you express (8) is the following general formula (10).

[In General Formula ^(10), V 1, n, Z and Y have the same meanings as in the formula (8). ]

<3> ^{R 7} in the general formula (8) is pre-Symbol photoelectric conversion element according to <1>, which is a group represented by the general formula (12) or (13).
<4> ^{R 7} in the general formula (8) is a photoelectric conversion element according to <1> or <3>, characterized in that a group represented by the following general formula (16).

<5> wherein Y is C _{(CH 3) 2,} wherein Z is characterized by an aliphatic group having 5 to 18 carbon atoms <1> to according to any one of <4> Photoelectric conversion element.
<6> is the Y is C _{(CH 3) 2,} wherein Z _{is, CH 3, C 2 H 5} , C 3 H 7 or characterized in that it is a _{CH 2 CH 2 COOH <1>} ~ < The photoelectric conversion element according to any one of 4 >.
< 7 > The photoelectric conversion element according to any one of < 1 > to < 6 >, wherein the V ¹ is a carboxy group or a salt thereof .
<8> wherein ^{V 1} is, 5 - carboxy sheet, wherein the group Oyo selected from the group consisting of beautiful 4,5 benzene ring condensed is at least one <1> to any one of <6> the photoelectric conversion device according to (1).
<9> wherein Z is 4-carboxyphenyl aliphatic group substituted with a phenyl group, wherein V ¹ is characterized in that it is a carboxyl group or a salt thereof <1> - or <4> 1 the photoelectric conversion element according to claim.

< 10 > The photoelectric conversion element according to any one of <1> to < 9 >, wherein the semiconductor fine particles are titanium oxide fine particles.
< 11 > A photoelectrochemical cell comprising the photoelectric conversion element according to any one of <1> to < 10 >.

  According to the present invention, it is possible to provide a photoelectric conversion element and a photoelectrochemical cell having high conversion efficiency and excellent durability.

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

  As a result of extensive studies, the present inventors have made a photoelectric conversion comprising a photoconductor having a semiconductor fine particle layer in which a specific combination of dyes is adsorbed on a conductive support, a charge transfer body, and a laminated structure including a counter electrode. It has been found that the device and the photoelectrochemical cell using the same have high conversion efficiency, and durability, particularly reduction in conversion efficiency is small. The present invention has been made based on this finding.

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 layer 2 constitute a light receiving electrode 5. The photoreceptor layer 2 has semiconductor fine particles 22 and a sensitizing dye (hereinafter also simply referred to as a dye) 21. At least a part of the sensitizing dye 21 is adsorbed on the semiconductor fine particles 22 (the sensitizing dye 21 is in an adsorption equilibrium state and may be partially present in the charge transfer layer 3). The charge transfer body layer 3 functions as, for example, a hole transport layer that transports holes. The conductive support 1 on which the photoreceptor layer 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 2 (semiconductor film) of semiconductor fine particles 22 adsorbed by a sensitizing dye 21 coated on the conductive support 1. Light incident on the photoreceptor layer 2 (semiconductor film) excites the dye. The excited dye has high energy electrons. Therefore, the electrons are transferred from the sensitizing dye 21 to the conduction band of the semiconductor fine particles 22 and reach the conductive support 1 by diffusion. At this time, the molecule of the sensitizing dye 21 is an oxidant. The electrons on the electrode return to the oxidant while working in the external circuit 6, thereby acting as the photoelectrochemical cell 100. At this time, the light receiving electrode 5 functions as a negative electrode of the battery.

  The photoelectric conversion element of the present invention has a photoreceptor having a porous semiconductor fine particle layer on which a combination of specific dyes described later is adsorbed on a conductive support. The photoreceptor is designed according to the purpose, and may have a single layer structure or a multilayer structure. The dye in the photoreceptor may be a mixture of many kinds of dyes, but at least two kinds of dyes described later are used. The photoconductor of the photoelectric conversion element of the present invention contains semiconductor fine particles to which these dyes are adsorbed, has high sensitivity, and when used as a photoelectrochemical cell, high conversion efficiency can be obtained. A photoelectric conversion element that is less deteriorated and excellent in durability can be obtained.

一般式（１）中、Ｑは少なくとも四官能以上の芳香族基を示す。芳香族基の例としては、芳香族炭化水素として、ベンゼン、ナフタレン、アントラセン、フェナントレンなどが挙げられ、芳香族へテロ環として、アントラキノン、カルバゾール、ピリジン、キノリン、チオフェン、フラン、キサンテン、チアントレンなどが挙げられ、これらは連結部分以外に置換基を有していてもよい。Ｑで表される芳香族基として、好ましくは芳香族炭化水素であり、さらに好ましくはベンゼン又はナフタレンであり、本発明では、４価のベンゼン環基である。ここで、ＱへのＸ^２とＮ（Ｒ’）の結合は、図示した式中で、Ｎ（Ｒ’）の位置にＸ^２が、Ｘ^２の位置にＮ（Ｒ’）が結合するものも含むものである。
(A) Dye (A1) Dye having the structure of the general formula (1) In the photoelectric conversion element of the present invention, a dye comprising a compound represented by the following general formula (1) is used.

In general formula (1), Q represents at least a tetrafunctional or higher aromatic group. Examples of aromatic groups include aromatic hydrocarbons such as benzene, naphthalene, anthracene, phenanthrene, and aromatic heterocycles such as anthraquinone, carbazole, pyridine, quinoline, thiophene, furan, xanthene, and thianthrene. These may have a substituent other than the linking moiety. The aromatic group represented by Q, preferably an aromatic hydrocarbon, more Ri preferably a benzene or naphthalene der, in the present invention, Ru der tetravalent benzene ring group. Here, ^{X 2} and N (R ') to Q bonds are in the illustrated formula, N (R' ^{which X 2} in position of) the, N (R ') is attached to the position of ^{X 2} Is also included.

X ¹ and X ² each independently represents a sulfur atom, an oxygen atom or CR ¹ R ² . X ¹ and X ² are preferably a sulfur atom or CR ¹ R ² , and most preferably CR ¹ R ² . Here, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R ¹ and R ² are preferably an aliphatic group or an aromatic group, more preferably an aliphatic group (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.).
However, in the present invention, X ¹ and X ² are CR ¹ R ² , and R ¹ and R ² are aliphatic groups.

R and R ′ each independently represents an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom, and these may be substituted. Preferably, it is an aliphatic group or an aromatic group (the number of carbon atoms of the aromatic group is preferably 5 to 16, more preferably 5 or 6. The number of carbon atoms of the aliphatic group is preferably 1 to More preferably, it is 1 to 6. Examples of the unsubstituted aliphatic group and aromatic group include methyl, ethyl, n-propyl, n-butyl, cyclohexyl, phenyl, naphthyl and the like.
However, in the present invention, R and R ′ are aliphatic groups.

P ¹ and P ² represent dye residues. The dye residue refers to an atomic group necessary for constituting the dye compound as a whole together with structures other than P ¹ and P ^{2 in} the general formula (1). P ¹ and P ² are bonded directly or via a linking group to constitute a dye of the general formula (1). Examples of the dye (dye compound) formed by P ¹ and P ² include polymethine dyes such as cyanine, merocyanine, rhodacyanine, trinuclear merocyanine, allopolar, hemicyanine, styryl, oxonol, and cyanine, acridine, xanthene, thioxanthene, and the like. Diarylmethine, triarylmethine, coumarin, indoaniline, indophenol, diazine, oxazine, thiazine, diketopyrrolopyrrole, indigo, anthraquinone, perylene, quinacridone, naphthoquinone, bipyridyl, terpyridyl, tetrapyridyl, phenanthroline, etc. .
Preferably, cyanine, merocyanine, rhodacyanine, trinuclear merocyanine, allopolar, hemicyanine, styryl and the like can be mentioned. In this case, cyanine includes those in which the substituent on the methine chain forming the dye forms a squalium ring or a croconium ring. For more information on these dyes, see FM Harmer, “Heterocyclic Compounds-Cyanine Dies and Related Compounds,” John, “Heterocyclic Compounds-Cyanine Soybeans and Reeled Compounds”, John. It is described in, for example, John Wiley & Sons, New York, London, 1964. The general formulas of cyanine, merocyanine and rhodacyanine are preferably those shown in (XI), (XII) and (XIII) of U.S. Pat. No. 5,340,694, pages 21,22. Further, preferably it has a squarylium ring in at least one of the methine chain moiety of the dye residue which is formed by P ¹ and P ^2, which has both are more preferred.

一般式（７）、（８）において、Ｖ^１は水素原子又は置換基を表す。ｎは０〜４の整数を表し、ｎが２以上の場合は、Ｖ^１は同じでも異なっていてもよく、又は互いに結合して環を形成していてもよい。ｎは好ましくは、０〜３であり、より好ましくは０〜２である。
ただし、本発明では、Ｖ ^１ は、カルボキシ基もしくはその塩、または２つのＶ ^１ が互いに結合してベンゼン環を形成する基を表す。ｎは０〜２の整数を表し、ｎが２の場合は、Ｖ ^１ は同じでも異なっていてもよい。
P ¹ and P ² in the dye having the structure of Formula (1) are each independently represented by the following general formula (7) or (8) it is rather preferable that represented, in the present invention have the general formula ( It is a group represented by 8) .

In the general formulas (7) and (8), V ¹ represents a hydrogen atom or a substituent. n represents an integer of 0 to 4, and when n is 2 or more, V ¹ may be the same or different, or may be bonded to each other to form a ring. n is preferably 0 to 3, more preferably 0 to 2.
However, in the present invention, V ¹ represents a carboxy group or a salt thereof, or a group in which two V ¹ are bonded to each other to form a benzene ring. n represents an integer of 0 to 2, and when n is 2, V ¹ may be the same or different.

Y represents a sulfur atom, NR ^a , or C (R ^b ) R ^c . R ^a represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. Preferred examples of R ^a are aliphatic groups (eg methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl etc.) or aromatic groups (eg phenyl , Tolyl, naphthyl, etc.). R ⁹ is more preferably an aliphatic group (eg, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.).
R ^b and R ^c represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded by a carbon atom, and R ^b and R ^c may be the same or different and are bonded to each other to form a ring May be formed. Preferred examples of R ^b and R ^c are aliphatic groups or aromatic groups, more preferably aliphatic groups (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.).
However, in the present invention, Y is C (R ^b ) R ^c , and R ^b and R ^c are aliphatic groups which may be the same or different.

Z represents an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom, and may have a substituent. Preferable examples of the substituent include an acidic group, more preferably a group having a carboxyl group. R ^{3 to} R ⁶ and R ⁸ represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and may have a substituent, preferably a hydrogen atom or an aliphatic group, more preferably Is a hydrogen atom. R ⁷ represents an oxygen atom or a divalent carbon atom in which the sum of σ _p in the Hammett rule of the two substituents to be bonded is positive.
However, in the present invention, Z is an aliphatic group and may be substituted with a carboxy group or a 4-carboxyphenyl group. R ⁶ and R ⁸ are a hydrogen atom or an aliphatic group. R ⁷ is an oxygen atom or a group represented by any one of the following general formulas (12) to (14).

The general formula (1) preferably has an acidic group in at least one of R, R ′, P ¹ and P ² . Here, the acidic group is a substituent having a dissociable proton, for example, carboxy shea group, a phosphonyl group, a sulfonyl group, and a group having a boric acid group, Oh preferably a group having a carboxyl group In the present invention, it is a carboxy group . Further, the acidic group may take a form of releasing a proton and dissociating. The salt may be sufficient.

In the general formula (1), W ¹ represents a counter ion when a counter ion is necessary to neutralize the charge. Generally, whether a dye is a cation, an anion, or has a net ionic charge depends on the auxiliary color groups and substituents in the dye. When the dye having the structure of the general formula (1) has a dissociable substituent, it may be dissociated and have a negative charge. In this case, the charge of the whole molecule is neutralized by W ^1.
When W ¹ is a cation, for example, it is an inorganic or organic ammonium ion (for example, a tetraalkylammonium ion or a pyridinium ion) or an alkali metal ion. When W ¹ is an anion, either an inorganic anion or an organic anion may be used. For example, halogen anion (for example, fluoride ion, chloride ion, bromide ion, iodide ion), substituted aryl sulfonate ion (for example, p-toluene sulfonate ion, p-chlorobenzene sulfonate ion), aryl disulfone Acid ion (for example, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion), alkyl sulfate ion (for example, methyl sulfate ion), sulfate ion, thiocyanate ion Perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, trifluoromethanesulfonate ion and the like. Furthermore, an ionic polymer or another dye having a charge opposite to that of the dye may be used as the charge balance counter ion, or a metal complex ion (for example, bisbenzene-1,2-dithiolatonickel (III)) may be used.

（Ｖ^１、ｎ、Ｚ、Ｙは前記一般式（７）及び（８）におけるものと同義である。）
It is preferable that P ¹ and P ² in the general formula (1) are independently represented by the following general formula (9) or (10). This results in a dye having a high molar extinction coefficient.
Among these, the group represented by the general formula (9) is a group of a reference example.

(V ¹ , n, Z and Y have the same meanings as in the general formulas (7) and (8).)

Wherein ^{R 7} in the general formula (8) is represented by the following general formula (11) to (14) rather is preferably that represented by any one of, in the present invention are represented by the general formula (12) to (14) Any group . In general formula (11)-(14), Rf represents a hydrogen atom or a substituent. Examples of the substituent include an aliphatic group, an aromatic group, and a heterocyclic group bonded with a carbon atom, and these may be substituted. Preferred substituents are aliphatic groups and aromatic groups. This enhances the absorption on the short wavelength side .
However, in the present invention, Rf is a hydrogen atom or an aliphatic group.

R ⁷ in the general formula (8) is preferably represented by the following general formula (15) or (16). As a result, the effect of improving the electron injection efficiency can be obtained.
In addition, General formula (15) is group of a reference example.

It is preferable that Y represents S, NCH ₃ , or C (CH ₃ ) ₂ and Z represents an aliphatic group having 5 to 18 carbon atoms. Z is preferably pentyl, hexyl, heptyl, 3,5,5-trimethylhexyl, decyl, octadecyl, more preferably decyl, octadecyl. Thereby, the conversion efficiency improvement by inefficient association suppression and the effect of the voltage drop suppression by the oxidation-reduction seed | species approach to the titanium oxide surface can be show | played.

In the general formulas (7) to (10), Y represents S, NCH ₃ , or C (CH ₃ ) ₂ , and Z is CH ₃ , C ₂ H ₅ , C ₃ H ₇ , or CH ₂ CH. It preferably represents ₂ COOH. As a result, the effect of improving the electron injection efficiency can be obtained.

In the general formulas (7) to (10), V ¹ preferably has an acidic group. Here, the acidic group is a substituent having a dissociative proton, and examples thereof include a group having a carboxy group , a phosphonyl, a sulfonyl group, a boric acid group, and the like. V ¹ may be an acid group salt.
V ¹ was a hydrogen atom, 5-carboxy sheet group, 5-sulfonyl group, to have 5-methyl or 4,5-benzene-fused preferred. Here, the position number is given counterclockwise, with N ⁺ being 1.
Thereby, the effect of improving the molar extinction coefficient or improving the electron injection efficiency is obtained.
However, in the present invention, the acidic group in V ¹ is a carboxy group or a salt thereof.

In the dye of the present invention represented by the general formula (1), the maximum absorption wavelength in a tetrahydrofuran: ethanol = 1: 1 solution is preferably in the range of 670 to 1100 nm, more preferably in the range of 700 to 900 nm.
Although the preferable specific example of a compound represented by General formula (1) of this invention below is shown, this invention is not limited to this.
Compounds S-1 to S-8, S-10 to S-12, S-15 to S-24, S-26 to S-28, and S-33 are reference examples.

  Synthesis of the dye having the structure of the general formula (1) is described in Ukrainski Kimicheskii Zhurnal, Vol. 40, No. 3, pages 253-258, Dyes and Pigments, Vol. Can be done with reference to.

(A2) Dye having a structure represented by the general formula (2) In the photoelectric conversion element and the photoelectrochemical cell of the present invention, the dye is composed of the compound represented by the general formula (1) and at least one kind of the following dye. At least one dye composed of the compound represented by the general formula (2) is used.

M (LL ¹ ) m ₁ (LL ² ) m ₂ (X) m ₃ · CI General formula (2)

In the dye of the general formula ( 2 ), the ligand LL ¹ and / or the ligand LL ² and optionally a specific functional group X are coordinated to a metal atom. It is kept neutral.
(A2-1) Metal atom M
M represents a metal atom. M 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 are Ru, Os, Zn or Cu, most preferably Ri Ru der, in the present invention, Ru Ru der.

(A2-2) Ligand LL ¹
The ligand LL ¹ is a bidentate or tridentate ligand represented by the bidentate or tridentate ligand represented by the following general formula (3), preferably a bidentate ligand. is there. _{M 1} representing the number of ligands LL ¹ is an integer of 0 to 3, preferably from 1 to 3, and more preferably 1. When m ₁ is 2 or more, LL ¹ may be the same or different. However, at least one of m ₁ and m ₂ representing the number of ligands LL ² described later is an integer of 1 or more. Thus the metal atom, the ligand LL ¹ and / or ligand LL ² is coordinated.
R ⁹ and R ¹⁰ in the general formula (3) each independently represent an acidic group or a salt thereof, for example, a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (preferably a hydroxamic acid having 1 to 20 carbon atoms) Groups such as —CONHOH, —CONCH ₃ OH, etc.), phosphoryl groups (eg —OP (O) (OH) ₂ etc.) and phosphonyl groups (eg —P (O) (OH) ₂ etc.) and salts thereof Preferably, they are a carboxyl group and a phosphonyl group, More preferably, a carboxyl group is mentioned. R ⁹ and R ¹³ may be substituted on any carbon atom on the pyridine ring.

In the formula, R ¹¹ and R ¹² 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 an ant having 6 to 26 carbon atoms) 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.), sulfonamide group (Preferably a sulfonamide 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, acetyl Oxy, 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 20 carbon atoms). An acylamino group 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 alkoxycarbonyl 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 ¹ contains an alkyl group, an alkenyl group or the like, these may be linear or branched, and may be substituted or unsubstituted. Further, when the ligand LL ¹ contains an aryl group, a heterocyclic group or the like, they may be monocyclic or condensed and may be substituted or unsubstituted.

In the general formula (3), R ¹³ and R ¹⁴ are each independently an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethyl. Pentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), aromatic groups (preferably carbon atoms) 6-30 aromatic groups, such as phenyl, substituted phenyl, naphthyl, substituted naphthyl, etc., or heterocyclic groups (preferably having 1-30 carbon atoms, such as 2-thienyl, 2-pyrrolyl, 2 -Imidazolyl, 1-imidazolyl, 4-pyridyl, 3-indolyl) are preferred. R ¹³ and R ¹⁴ are preferably a heterocyclic group or a carbocyclic aromatic group in which the heterocyclic ring is condensed. Examples of the carbocyclic aromatic group condensed with a heterocycle include benzofuran, isobenzofuran, indole, benzothiophene, benzimidazole, benzothiazole, and benzodithiophene. R ¹³ and R ¹⁴ preferably have a plurality of heterocycles. Examples of those having a plurality of heterocycles include thienothiophene and dithienothiophene. The heterocyclic group is preferably at least one selected from the group consisting of a thiophene ring, a pyrrole ring and a furan ring. The heterocyclic group preferably has an electron donating group. More preferably, it has 1 to 3 electron donating groups. Examples of the electron donating group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, and an acylamino group (the preferred examples are the same as those for R ¹¹ and R ¹² ). Or an hydroxyl group, more preferably an alkyl group, an alkynyl group, an aryl group, an alkoxy group or an amino group, and particularly preferably an alkyl group or an alkynyl group. R ¹³ and R ¹⁴ may be the same or different, but are preferably the same.

R ¹³ and R ¹⁴ may be directly bonded to the pyridine ring. As for R ¹³ and R ¹⁴ directly bonded to the pyridine ring, in the following general formula (5-1), at least one of R ⁴¹ and R ⁴² is an alkyl group (for example, a substituted or unsubstituted carbon number). 1-20 alkyl groups (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-octyl, n-nonyl, n-dodecyl, cyclohexyl, benzyl, etc.), alkynyl groups In the formula (5-1), R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , a1, a2, b1 and b2 are the same as those in the formula (3). It is synonymous.

R ¹³ and R ¹⁴ may be bonded to the pyridine ring via L ¹ and / or L ² . In the general formula (3), d1 and d2 each represents an integer of 0 or more. It is preferable that d1 and d2 are both integers of 1 or more. d1 and d2 are preferably an integer of 1 to 3, more preferably an integer of 1 to 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. 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.

n is 0 or 1, and a1 and a2 each independently represent an integer of 0 to 3. a1 is may be the R ⁹ when 2 or more be the same or different, a2 is the R ¹⁰ when two or more 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 n is 0, a2 is preferably 1 or 2, and when n 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 ¹² may be the same or different and may be connected to each other to form a ring. When b2 is 2 or more, R ¹³ may be the same or different and may be connected to each other to form a ring. When both b1 and b2 are 1 or more, R ¹² and R ¹³ 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 ¹ is having at least one acidic group or a salt thereof is preferably m1 in formula (8) is 2 or 3, 2 It is more preferable that

［ 一般式（５−２）におけるＲ^９、Ｒ^１０、Ｒ^１１、Ｒ^１２、ａ１、ａ２、ｂ１及びｂ２は、一般式（３）におけるものと同義である。Ｒ^５１及びＲ^５２は置換基である。ｎは１以上の整数を表す。］ LL ¹ in the general formula (1) is preferably represented by the following general formula (5-2).

[R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , a1, a2, b1 and b2 in General Formula (5-2) have the same meanings as in General Formula (3). R ⁵¹ and R ⁵² are substituents. n represents an integer of 1 or more. ]

Examples of the substituents R ⁵¹ and R ⁵² are the same as those of R ¹³ and R ¹⁴ in the general formula (3). Examples of the substituents R ⁵¹ and R ⁵² include aliphatic groups (for example, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t -Butyl, n-octyl, n-nonyl, n-dodecyl, cyclohexyl, benzyl, etc.), alkenyl group, alkynyl group, cycloalkyl group, alkoxy group, aryl group, aryloxy group, amino group, acylamino group (more preferred examples) a case similar) or hydroxyl groups of R ¹³ and R ¹⁴ in the general formula (3), more preferably an alkyl group, an alkynyl group, an aryl group, an amino group, more preferably, the R ⁵¹ and R at least one of ^52, an alkyl group, an alkynyl group, an aryl group, selected from the group consisting of an alkenyl group Was is preferably at least one. Among these alkyl groups, alkynyl groups are preferred.

LL ¹ in the general formula (1) is preferably represented by the following general formula (5-3). Here, R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , a1, a2, b1, and b2 in (5-3) have the same meanings as in general formula (3). n represents an integer of 1 or more, and R ⁵¹ , R ⁵² , R ^53, and R ⁵⁴ represent a substituent. Examples of the substituents R ⁵³ and R ⁵⁴ include the same groups as R ¹³ and R ¹⁴ in the general formula (3). As the substituents R ⁵³ and R ⁵⁴ , an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, an acylamino group (preferred examples are the general formula (3 can be exemplified when the same) or hydroxyl group R ⁹ in). It is preferable that at least one of R ⁵³ and R ⁵⁴ is at least one selected from the group consisting of an alkyl group, an alkynyl group, and an aryl group.

LL ¹ in the general formula (1) is preferably represented by the following general formula (5-4) or (5-5).
In the following general formulas (5-4) and (5-5), R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , a1, a2, b1 and b2 have the same meanings as in general formula (3). R ⁶¹ , R ⁶² , R ⁷¹ , R ⁷² , R ⁷³ and R ⁷⁴ represent a substituent. f1 and f2 represent an integer of 0 or more. n represents an integer of 1 or more. Examples of the substituents R ⁶¹ , R ⁶² , R ⁷¹ , R ⁷² , R ^73, and R ⁷⁴ are the same as R ¹³ and R ¹⁴ in the general formula (3).
As R ⁶¹ and R ⁶² , an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, and an acylamino group (preferred examples are R ¹³ in the general formula (3) and As in R ¹⁴ ) or a hydroxyl group. The substituents R ⁶¹ and R ⁶² are preferably an alkyl group and an amino group.

In the general formula (5-5), R ^{71 to} R ⁷⁴ are 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. R ¹³ and R ¹⁴ in the formula (3)), and more preferably an alkyl group, an alkoxy group, an amino group, or an acylamino group.

In general formulas (5-4) and (5-5), R ^{71 to} R ⁷⁴ are preferably each independently hydrogen, an alkyl group, an alkenyl group, or an aryl group. Further preferred examples of R ^{71 to} R ⁷⁴ are the same as the preferred examples of R ¹³ and R ¹⁴ in formula (3). R ^{71 to} R ⁷⁴ are more preferably an alkyl group or an aryl group, and more preferably an alkyl group. When R ^{71 to} R ⁷⁴ 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, particularly preferably an alkoxy group. R ⁷¹ and R ^{72 and} R ⁷³ and R ⁷⁴ 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 the general formula ^{(5-5), R 15} has the same meaning as ^{R 10} in the general formula ^{(3), R 16} has the same meaning as ^{R 10} in the general formula (3). a3 represents an integer of 0 to 3, preferably an integer of 0 to 2. When n is 1, a3 is preferably 0 or 1. a3 is 2 or more when R ¹⁵ may be the same or different.

In general formulas (5-4) and (5-5), d1 and d2 each independently represent an integer of 0 to 4. When d1 is 1 or more, R ²¹ may be linked to R ¹⁷ and / or R ¹⁸ to form a ring. The ring formed is preferably a piperidine ring or a pyrrolidine ring. When d1 is 2 or more, R ²¹ may be the same or different, and may be connected to each other to form a ring. When d2 is 1 or more, R ²² may be linked to R ¹⁹ and / or R ²⁰ to form a ring. The ring formed is preferably a piperidine ring or a pyrrolidine ring. When d2 is 2 or more, R ²² may be the same or different, and may be linked to each other to form a ring.

なお、本発明においては、配位子ＬＬ ^１ は前記一般式（５−３）で表される２座の配位子であって、該一般式（５−３）において、Ｒ ^９ およびＲ ^１０ はそれぞれ独立に、カルボキシ基、スルホ基、ヒドロキシ基、ヒドロキサム酸基、ホスホリル基もしくはホスホニル基またはこれらの塩であり、Ｒ ^１１ およびＲ ^１２ はそれぞれ独立に置換基である。ａ１、ａ２、ｂ１およびｂ２は０である。ｎは１である。Ｒ ^５３ およびＲ ^５４ はアルキニル基またはアリール基である。
また、一般式（２）におけるｍ _１ は１である。
In general formula (5-5), b3 represents the integer of 0-5, Preferably the integer of 0-3 is represented. b3 is preferably an integer of 1 to 3. When b3 is 2 or more, R ¹⁶ may be the same or different, and may be connected to each other to form a ring. When b1 and b3 in general formula (5-5) are both 1 or more, R ¹¹ and R ¹⁶ may be linked to form a ring. As the ring formed, a benzene ring, a cyclopentane ring or a cyclohexane ring is preferable.

In the present invention, the ligand LL ¹ is a bidentate ligand represented by the general formula (5-3), and in the general formula (5-3), R ⁹ and R ¹⁰ Are each independently a carboxy group, a sulfo group, a hydroxy group, a hydroxamic acid group, a phosphoryl group or a phosphonyl group, or a salt thereof, and R ¹¹ and R ¹² are each independently a substituent. a1, a2, b1 and b2 are 0. n is 1. R ⁵³ and R ⁵⁴ are an alkynyl group or an aryl group.
Further, m ₁ in the general formula (2) is 1.

一般式（４）中、Ｚａ、Ｚｂ及びＺｃはそれぞれ独立に、５員環又は６員環を形成しうる非金属原子群を表す。形成される５員環又は６員環は置換されていても無置換でもよく、単環でも縮環していてもよい。Ｚａ、Ｚｂ及びＺｃは炭素原子、水素原子、窒素原子、酸素原子、硫黄原子、リン原子及び／又はハロゲン原子で構成されることが好ましく、芳香族環を形成するのが好ましい。５員環の場合はイミダゾール環、オキサゾール環、チアゾール環又はトリアゾール環を形成するのが好ましく、６員環の場合はピリジン環、ピリミジン環、ピリダジン環又はピラジン環を形成するのが好ましい。なかでもイミダゾール環又はピリジン環がより好ましい。
一般式（４）中、ｃは０または１を表す。ｃは０であるのが好ましく、ＬＬ^２は２座配位子であるのが好ましい。 (A2-3) Ligand LL ²
In the general formula (2), LL ² represents a bidentate or tridentate ligand. _{M 2} representing the number of ligands LL ² is an integer of 0 to 2, is preferably 0 or 1. When m ₂ is 2, LL ² may be the same or different. However, at least one is an integer equal to or greater than 1 among m ₂ and m ₁ representing the number of the ligand LL ¹ described above.
Ligand LL ² is a bidentate or tridentate ligand represented by the following general formula (4).

In General Formula (4), 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 (4), c represents 0 or 1. c is preferably 0, and LL ² is preferably a bidentate ligand.

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

In general formulas (6-1) to (6-8), R ^{25 to} R ³² each independently represents an acidic group or a salt thereof. R ^{25 to} R ³² 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.), phosphoryl group ( For example, —OP (O) (OH) ₂ etc.) or a phosphonyl group (eg —P (O) (OH) ₂ etc.) or a salt thereof is represented. R ^{25 to} R ³² 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 (6-1) to (6-8), R ^{33 to} R ⁴⁰ 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 (above preferred examples are R ¹³ and R ¹⁴ in formula (3)) More preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a halogen atom, particularly preferably an alkyl group or an alkenyl group. An alkoxy group, an alkoxycarbonyl group, an amino group, or an acylamino group. .

In formulas (6-1) to (6-8), R ^{41 to} R ⁴⁵ 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 general formulas (6-1) to (6-8), R ^{25 to} R ⁴⁰ 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. e7 and e8 each independently represents an integer of 0 to 4, preferably an integer of 0 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 ^{25 to} R ³² may be the same or different, and when e9 to e16 is 2 or more, R ^{33 to} R ⁴⁰ may be the same or different and are connected to each other. To form a ring.
In the present invention, the ligand LL ² is a bidentate ligand represented by the general formula (4), and in the general formula (4), Za, Zb and Zc are each independently And a non-metal atom group capable of forming a pyridine ring, each of which may independently have an acidic group selected from a carboxy group and a salt thereof. c is 0.
Further, m ₂ in the general formula (2) is 1.

(A2-4) Ligand X
In general formula (2), X represents a monodentate or bidentate ligand. M ₃ representing the number of ligands X represents an integer of 0 to 2, and m ₃ is preferably 1 or 2. When X is a monodentate ligand, m ₃ is preferably 2. When X is a bidentate ligand, m ₃ is preferably 1. When m ₃ is 2, Xs may be the same or different, and Xs may be linked together.

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), 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, 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 cyano group, A ligand coordinated by a group selected from the group consisting of an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a ligand consisting of a halogen atom, carbonyl, 1,3-diketone or thiourea, More preferably, a ligand coordinated 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, or Halogen atom 1,3 A ligand comprising a diketone or thiourea, particularly preferably a ligand coordinated by a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group, an isothiocyanate group, a cyanate group and an isocyanate group, or a halogen atom Or a ligand consisting of a 1,3-diketone, most preferably a ligand coordinated with a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group and an isothiocyanate group, or a 1,3-diketone A ligand consisting of 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.

When X is a bidentate ligand, X is an acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithio A ligand coordinated by a group selected from the group consisting of a carbonate group, an acyl group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a 1,3-diketone, carbonamide, thiocarbonamide, or thio A ligand composed of urea is preferable. When X is a monodentate ligand, X is a ligand coordinated by a group selected from the group consisting of a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, and an arylthio group, or A ligand composed of a halogen atom, carbonyl, dialkyl ketone, or thiourea is preferred.
In the present invention, X is a monodentate ligand coordinated with a group selected from the group consisting of a thiocyanate group, an isothiocyanate group, a cyanate group and an isocyanate group.
Further, m ₃ in the general formula (2) is 2.

(A2-5) Counter ion CI
CI in the general formula (2) represents a counter ion when a counter ion is required 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 (2) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the entire charge of the dye of the general formula (2) 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. Further, 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.

(A2-6) Bonding Group The dye having the structure represented by the general formula (2) preferably has at least one suitable bonding group (interlocking group) for the surface of the semiconductor fine particles. It is more preferable to have 1 to 6 bonding groups in the dye, and it is particularly preferable to have 1 to 4 bonding groups. Carboxy shea group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (e.g., -CONHOH, etc.), a phosphoryl group (e.g., -OP (O) _{(OH) 2,} etc.), phosphonyl group (e.g., -P (O) _{(OH) 2} Etc.) in the dye.
In the present invention, the acidic group of the linking group is a carboxy group.

Specific examples of the dye having the structure represented by the general formula (2) used in the present invention are shown below, but the present invention is not limited thereto. 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.
Here, dyes R-1 to R-7, R-9 to R11, Z-1, C-1, and O-1 are reference examples.

Specific examples of the general formula (2) are further shown below, but the present invention is not limited thereto. Moreover, although these acidic groups show only proton non-dissociated products, these proton dissociated products may be used. As the ligand LL ¹ of the general formula (2), the following A-1-1 to A-1-14, A-2-1 to A-2-14 and A-16-1 to A-16- 10 can be mentioned.
The other examples are reference examples.

Specific examples of LL ² such as B-1-1 , B-10-5, and B-11-6 are shown below, but the present invention is not limited thereto. Moreover, although these acidic groups show only proton non-dissociated products, these proton dissociated products may be used.
The remaining ligands are reference examples .

The ligand of a reference example is shown with Z-44-Z-47 which is a specific example of the ligand Z below.
Note that the structural formula shown below is only one of the many possible resonance structures, and the distinction between a covalent bond (indicated by-) and a coordination bond (indicated by ...) is also formal. It does not represent an absolute distinction.

Although the specific example of the pigment | dye represented by General formula (2) below is shown, this invention is not limited to these. Moreover, although these acidic groups show only proton non-dissociated products, these proton dissociated products may be used. Furthermore, these compounds can be isomers such as cis isomers, trans isomers and mixtures thereof, and optically active isomers, but are not particularly limited.
Here, the dyes of the present invention are D-1-1a to D-2-3, D-1-14, D-1-21a to D-1-22c, D-1-24a to 24c, D-7. -1, D-7-2, D-7-14, D-7-21, D-7-22, and the rest are reference examples.

The dye represented by the general formula (2) of the present invention can be synthesized with reference to JP-A No. 2001-291534 and the methods cited in the publication.
The dye composed of the compound of the general formula (2) has a maximum absorption wavelength in the solution of preferably 300 to 1000 nm, more preferably 350 to 950 nm, and particularly preferably 370 to 900 nm. .
Moreover, as for the pigment | dye which consists of a compound of General formula (1), the maximum absorption wavelength in a solution becomes like this. Preferably it is the range of 670-1100 nm, More preferably, it is the range of 700-900 nm.
In the photoelectric conversion element and the photoelectrochemical cell of the present invention, light having a wide range of wavelengths is used by using at least the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2). By doing so, high conversion efficiency can be ensured. Furthermore, the combined use of these dyes can reduce the rate of decrease in conversion efficiency.

  The blending ratio of the metal complex dye represented by the general formula (2) and the dye represented by the general formula (1) is R / S = 90/10 in the ratio of mol%, where R is the former and S is the latter. 10/90, preferably R / S = 80/20 to 20/80, more preferably R / S = 70/30 to 30/70, even more preferably R / S = 60/40 to 40/60, Most preferably, R / S = 55/45 to 45/55, and usually equimolar amounts of both are used.

(B) Conductive Support As shown in FIG. 1, in the photoelectric conversion element of the present invention, a photosensitive member 2 in which a dye 21 is adsorbed on porous semiconductor fine particles 22 is formed on a conductive support 1. ing. As described later, for example, the photosensitive layer can be produced by immersing the dispersion of semiconductor fine particles in the dye solution of the present invention after coating and drying on a 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.

In the present invention, a metal support can be used as a preferable conductive support. As the conductive metal support, a conductive metal support composed of any element belonging to Group 4 to Group 13 is used as the conductive support. Here, Group 4 to Group 13 are those in the long-period periodic table.
The thickness of the conductive metal support in the present invention is preferably 10 μm or more and 2000 μm or less, more preferably 10 μm or more and 1000 μm or less, and particularly preferably 50 μm or more and 500 μm or less. When this thickness is too thick, flexibility is lacking, which may cause trouble when used as a photoelectric conversion element. Moreover, when too thin, it may be damaged during use of the photoelectric conversion element, which is not preferable.
The lower the surface resistance of the conductive metal support used in the present invention, the better. The range of the surface resistance is preferably 10Ω / m ² or less, more preferably 1Ω / m ² or less, and particularly preferably 0.1Ω / m ² or less. When this value is too high, it becomes difficult to energize and the function as a photoelectric conversion element cannot be exhibited.

  As the conductive metal support, at least one selected from the group consisting of titanium, aluminum, copper, nickel, iron, stainless steel, zinc, molybdenum, tantalum, niobium, and zirconium can be preferably used. These metals may be alloys. Of these, titanium, aluminum, copper, nickel, iron, stainless steel, and zinc are more preferred, titanium, aluminum, and copper are more preferred, and titanium and aluminum are most preferred. In the case of aluminum, aluminum alloy wrought material, 1000 series to 7000 series (Light Metal Association: Aluminum Handbook, Light Metal Association, (1978), 26) and the like can be preferably used.

Since the conductive metal support has a small surface resistance and can reduce the internal resistance of the photoelectrochemical cell, a high output battery can be obtained. Further, when a conductive metal support is used, the support does not soften even if the conductive metal support coated with the semiconductor fine particle dispersion described below is heated and dried at a high temperature. . Therefore, a porous semiconductor fine particle layer having a large specific surface area can be formed by appropriately selecting the heating conditions. Thereby, the amount of dye adsorption can be increased, and a photoelectric conversion element with high output and high conversion efficiency can be provided.
Moreover, a porous electroconductive support body can be obtained by apply | coating a semiconductor fine particle dispersion liquid to this metal sheet | seat, and heating after that while winding the metal sheet | seat continuously. Thereafter, the photosensitive layer can be formed on the conductive support by continuously applying the dye of the present invention. By passing through this process, it becomes possible to manufacture a photoelectric conversion element and a photoelectrochemical cell at low cost.

As the conductive metal support of the present invention, a conductive metal layer provided on a polymer material layer can be preferably used. The polymer material layer is not particularly limited, but a material that does not melt and retain its shape when heated after coating the semiconductor fine particle dispersion on the conductive layer is selected. The conductive layer can be produced by laminating the polymer material layer by a conventional method such as extrusion coating.
Examples of the polymer material layer that can be used include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), and polycarbonate (PC ), Polyarylate (PAr), polysulfone (PSF), polyester sulfone (PES), polyetherimide (PEI), cyclic polyolefin, brominated phenoxy and the like.
As the conductive metal support of the present invention, a polymer material layer provided with a conductive layer is used so that the polymer material layer functions as a protective layer for a photoelectric conversion element or a photoelectrochemical cell. Is possible. If an electrically insulating material is used as the polymer material, the polymer material layer can function not only as a protective layer but also as an insulating layer. Thereby, the insulation of photoelectric conversion element itself can be ensured. When the polymer material layer is used as an insulating layer, it is preferable to use a material having a volume resistivity of 10 ¹⁰ to 10 ²⁰ Ω · cm. More preferably, the volume resistivity is 10 ¹¹ to 10 ¹⁹ Ω · cm. If an electrically conductive material is not blended using the above materials, an insulating layer having a volume resistivity within this range can be obtained.
The conductive metal support is preferably substantially transparent. Substantially transparent means that the light transmittance is 10% or more, preferably 50% or more, particularly preferably 80% or more.

A light management function may be provided on the surface of the conductive metal support. For example, an antireflection film in which high refractive films and low refractive index oxide films are alternately stacked, or a light guide function may be provided.
It is preferable that the conductive support has a function of blocking ultraviolet light. For example, there is a method in which a fluorescent material capable of changing ultraviolet light into visible light is present inside or on the surface of the polymer material layer. Another preferred method is a method using an ultraviolet absorber. A function described in JP-A-11-250944 may be provided on the conductive support.
Since the resistance value of the conductive film increases as the cell area increases, a collecting electrode may be disposed. As a preferable shape and material of the current collecting electrode, those described in JP-A No. 11-266028 can be used. A gas barrier film and / or an ion diffusion preventing film may be disposed between the polymer material layer and the conductive layer. As the gas barrier layer, either a resin film or an inorganic film may be used.

(C) Semiconductor Fine Particle As shown in FIG. 1, in the photoelectric conversion element of the present invention, a photosensitive layer 2 in which a dye 21 is adsorbed on a semiconductor fine particle 22 is formed on a conductive support 1. As will be described later, for example, a dispersion of semiconductor fine particles is applied to the conductive support and dried, and then immersed in the dye solution of the present invention to produce a photoreceptor.
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.

In semiconductors, there are an n-type in which carriers involved in conduction are electrons and a p-type in which carriers are holes. In the element of the present invention, 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 equal carrier concentration due to conduction band electrons and valence band holes, the electron carrier concentration is reduced due to 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 improving the light capture rate by scattering incident light, large particles having an average particle size exceeding 50 nm can be added to the above ultrafine particles at a low content. 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.

  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 high-temperature hydrolysis of 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, an additive to the titania may be used as a binder for improving necking or an additive on the surface for preventing 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.

(D) Semiconductor Fine Particle Dispersion In the present invention, a porous semiconductor fine particle coating layer can be obtained by applying a semiconductor fine particle dispersion to the conductive support and heating appropriately.
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.
If the viscosity of the semiconductor fine particle dispersion is too high, the dispersion will aggregate and cannot be formed into a film. Conversely, if the viscosity of the semiconductor fine particle dispersion is too low, the liquid will flow and cannot be formed into 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. In addition, the application method and the metering method can be made the same part. 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 of the present invention 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 to heat treatment, light energy can also be used. For example, when titanium oxide is used as the semiconductor fine particles, the surface may be activated by applying light absorbed by the semiconductor fine particles such as ultraviolet light, or only the surface of the semiconductor fine particles may be activated by laser light or the like. Can do. By irradiating the semiconductor fine particles with light absorbed by the fine particles, the impurities adsorbed on the particle surface are decomposed by the activation of the particle surface, and can be brought into a preferable state for the above purpose. When heat treatment and ultraviolet light are combined, it is preferable that heating be performed at 100 ° C. or higher and 250 ° C. or lower, or preferably 100 ° C. or higher and 150 ° C. or lower, while irradiating the semiconductor fine particles with light absorbed by the fine particles. Thus, by photoexciting the semiconductor fine particles, impurities mixed in the fine particle layer can be washed by photolysis, and physical bonding between the fine particles can be strengthened.

In addition, the semiconductor fine particle dispersion may be applied to the conductive support, and other treatments may be performed in addition to heating and light irradiation. Examples of preferred methods include energization and chemical treatment.
A pressure may be applied after application, and examples of a method for applying pressure include Japanese Patent Application Publication No. 2003-500857. Examples of light irradiation include JP-A No. 2001-357896. Examples of plasma, microwave, and energization include JP-A-2002-353453. Examples of the chemical treatment include JP-A-2001-357896.

The method for coating the above-mentioned semiconductor fine particles on the conductive support is not only the method for coating the above-mentioned semiconductor fine particle dispersion on the conductive support, but also the semiconductor fine particle precursor described in Japanese Patent No. 2664194. A method such as a method of obtaining a semiconductor fine particle film by coating on a conductive support and hydrolyzing with moisture in the air can be used.
Examples of the precursor include (NH ₄ ) ₂ TiF ₆ , titanium peroxide, metal alkoxide / metal complex / metal organic acid salt, and the like.
Also, a method of forming a semiconductor film by applying a slurry in which a metal organic oxide (such as an alkoxide) coexists, and heat treatment, light treatment, etc., a slurry in which an inorganic precursor coexists, titania dispersed in the slurry pH The method which specified the property of particle | grains is mentioned. A binder may be added to these slurries in a small amount, and examples of the binder include cellulose, fluoropolymer, crosslinked rubber, polybutyl titanate, carboxymethyl cellulose and the like.
Techniques related to the formation of semiconductor fine particles or precursor layers thereof include corona discharge, plasma, a method of hydrophilizing by physical methods such as UV, a chemical treatment with alkali, polyethylenedioxythiophene and polystyrenesulfonic acid, polyaniline, etc. For example, formation of an interlayer film for bonding may be mentioned.

As a method of coating the semiconductor fine particles on the conductive support, (2) the dry method and (3) other methods may be used in combination with the above (1) wet method.
(2) As a dry method, JP 2000-231943 A is preferable.
(3) As other methods, JP-A-2002-134435 is preferable.

Examples of the dry method include vapor deposition, sputtering, and aerosol deposition method. Further, electrophoresis or electrodeposition may be used.
Moreover, after producing a coating film once on a heat-resistant board | substrate, you may use the method of transcribe | transferring to films, such as a plastics. Preferably, a method of transferring via EVA described in JP-A No. 2002-184475, a semiconductor layer / conductive layer on a sacrificial substrate containing an inorganic salt that can be removed with ultraviolet rays and an aqueous solvent described in JP-A No. 2003-98977 And a method of removing the sacrificial substrate after transfer to an organic substrate.

  The semiconductor fine particles preferably have a large surface area so that many dyes can be adsorbed. For example, in a state where the semiconductor fine particles are coated on the support, the surface area is preferably 10 times or more, more preferably 100 times or more the projected area. Although there is no restriction | limiting in particular in this upper limit, Usually, it is about 5000 times. JP-A-2001-93591 and the like are preferable as the structure of the semiconductor fine particles.

In general, as the thickness of the semiconductor fine particle layer increases, the amount of dye that can be supported per unit area increases, so that the light absorption efficiency increases. However, the diffusion distance of the generated electrons increases, and the loss due to charge recombination also increases. The preferred thickness of the semiconductor fine particle layer varies depending on the use of the device, but is typically 0.1 to 100 μm. When using as a photoelectrochemical cell, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 3-30 micrometers. The semiconductor fine particles may be heated at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours in order to adhere the particles to each other after being applied to the support. When glass is used as the support, the film forming temperature is preferably 400 to 600 ° C.
When a polymer material is used as the support, it is preferably heated after film formation at 250 ° C. or lower. In this case, the film forming method may be any one of (1) a wet method, (2) a dry method, and (3) an electrophoresis method (including an electrodeposition method), preferably (1) a wet method, or ( 2) A dry method, more preferably (1) a wet method.
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 semiconductor electrode after film formation in the dye adsorbing dye solution comprising the solution and the dye of the present invention. The solution used for the dye solution for dye adsorption can be used without particular limitation as long as it is a solution that can dissolve the dye of the present invention. 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.
The dye solution for dye adsorption comprising the solution and the dye of the present invention may be heated to 50 ° C. to 100 ° C. as necessary. 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 adsorbed needs to be used in combination with a dye having the structure of the general formula (1) and a dye having the structure of the general formula (2). You may further mix other pigment | dye within the range which does not impair the meaning of this invention. 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 necessary to prepare a dye solution for dye adsorption so that all the dyes are dissolved.

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 the pigment | dye of this invention 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. On the other hand, when the amount of the dye is small, the sensitizing effect is insufficient, and when the amount of the dye is too large, the dye not attached to the semiconductor floats and causes the sensitizing effect to be reduced.

Further, a colorless compound may be co-adsorbed for the purpose of reducing the interaction between dyes such as association. Examples of the hydrophobic compound to be co-adsorbed include steroid compounds having a carboxyl group (for example, cholic acid and pivaloyl acid).
After adsorbing the dye, the surface of the semiconductor fine particles may be treated with amines. Preferred amines include 4-tert-butyl pyridine, polyvinyl pyridine and the like. These may be used as they are in the case of a liquid, or may be used by dissolving in an organic solvent.

  The counter electrode functions as a 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.
A composite electrode such as titanium oxide and tin oxide (TiO ₂ / SnO ₂ ) may be used as the light receiving electrode, and as a mixed electrode of titania, for example, Japanese Patent Application Laid-Open No. 2000-119393 may be cited. Examples of mixed electrodes other than titania include JP-A Nos. 2001-185243 and 2003-282164.

The light receiving electrode may be a tandem type in order to increase the utilization rate of incident light. Examples of preferable tandem type configurations include those described in JP-A No. 2002-90989.
A light management function for efficiently performing light scattering and reflection inside the light receiving electrode layer may be provided. Preferably, the thing of Unexamined-Japanese-Patent No. 2002-93476 is mentioned.

A short-circuit prevention layer is preferably formed between the conductive support and the porous semiconductor fine particle layer in order to prevent a reverse current due to direct contact between the electrolyte and the electrode. Preferable examples include Japanese Patent Application Laid-Open No. 06-507999.
In order to prevent contact between the light receiving electrode and the counter electrode, it is preferable to use a spacer or a separator. A preferable example is JP-A No. 2001-283941.

(E) Electrolyte As a typical redox couple, for example, a combination of iodine and iodide (for example, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.), alkyl viologen (for example, methyl viologen chloride, hexyl) A combination of viologen bromide, benzyl viologen tetrafluoroborate) and its reduced form, a combination of polyhydroxybenzenes (eg, hydroquinone, naphthohydroquinone, etc.) and its oxidant, and a divalent and trivalent iron complex (eg, red blood salt) And a combination of yellow blood salt). Of these, a combination of iodine and iodide is preferred. As the organic solvent for dissolving them, an aprotic polar solvent (for example, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3-methyloxazolidinone, etc.) is preferable. Examples of the polymer used for the matrix of the gel electrolyte include polyacrylonitrile and polyvinylidene fluoride. Examples of the molten salt include those imparted with fluidity at room temperature by mixing polyethylene oxide with lithium iodide and at least one other lithium salt (for example, lithium acetate, lithium perchlorate, etc.). It is done. In this case, the amount of the polymer added is 1 to 50% by mass. Moreover, (gamma) -butyrolactone may be contained in electrolyte solution, and thereby the diffusion efficiency of iodide ion becomes high and conversion efficiency improves.

  As an additive to the electrolyte, in addition to the aforementioned 4-tert-butylpyridine, an aminopyridine compound, a benzimidazole compound, an aminotriazole compound and an aminothiazole compound, an imidazole compound, an aminotriazine compound, a urea derivative, Amide compounds, pyrimidine-based compounds and nitrogen-free heterocycles can be added.

  In order to improve efficiency, a method of controlling the water content of the electrolytic solution may be used. Preferred methods for controlling moisture include a method for controlling the concentration and a method in which a dehydrating agent is allowed to coexist. In order to reduce the toxicity of iodine, an inclusion compound of iodine and cyclodextrin may be used, and conversely, a method of constantly supplying water may be used. Cyclic amidine may be used, and an antioxidant, hydrolysis inhibitor, decomposition inhibitor, and zinc iodide may be added.

  Molten salts may be used as the electrolyte, and preferred molten salts include ionic liquids containing imidazolium or triazolium type cations, oxazolium-based, pyridinium-based, guanidinium-based, and combinations thereof. These cationic systems may be combined with specific anions. Additives may be added to these molten salts. You may have a liquid crystalline substituent. Further, a quaternary ammonium salt-based molten salt may be used.

  As molten salts other than these, for example, flowability at room temperature was imparted by mixing polyethylene oxide with lithium iodide and at least one other lithium salt (for example, lithium acetate, lithium perchlorate, etc.). And the like.

  The electrolyte may be quasi-solidified by adding a gelling agent to an electrolyte solution composed of an electrolyte and a solvent to cause gelation. Examples of the gelling agent include organic compounds having a molecular weight of 1000 or less, Si-containing compounds having a molecular weight in the range of 500 to 5000, organic salts made of specific acidic compounds and basic compounds, sorbitol derivatives, and polyvinylpyridine.

Alternatively, a method of confining the matrix polymer, the crosslinkable polymer compound or monomer, the crosslinking agent, the electrolyte, and the solvent in the polymer may be used.
As a matrix polymer, a polymer having a nitrogen-containing heterocyclic ring in a repeating unit of a main chain or a side chain, a crosslinked product obtained by reacting these with an electrophilic compound, a polymer having a triazine structure, or having a ureido structure Polymers, liquid crystalline compounds, ether-bonded polymers, polyvinylidene fluorides, methacrylates / acrylates, thermosetting resins, crosslinked polysiloxanes, PVA, inclusion compounds such as polyalkylene glycol and dextrin, Examples include systems to which oxygen or sulfur-containing polymers are added, natural polymers, and the like. An alkali swelling polymer, a polymer having a compound capable of forming a charge transfer complex between a cation moiety and iodine in one polymer may be added to these.

  As the matrix polymer, a system including a cross-linked polymer obtained by reacting a functional group such as a hydroxyl group, an amino group, or a carboxyl group with one or more functional isocyanate as one component may be used. Further, a crosslinking method in which a crosslinked polymer composed of a hydrosilyl group and a double bond compound, polysulfonic acid, polycarboxylic acid, or the like is reacted with a divalent or higher valent metal ion compound may be used.

  Examples of the solvent that can be preferably used in combination with the quasi-solid electrolyte include a specific phosphate ester, a mixed solvent containing ethylene carbonate, and a solvent having a specific dielectric constant. The liquid electrolyte solution may be held in a solid electrolyte membrane or pores, and preferred methods thereof include conductive polymer membranes, fibrous solids, and cloth solids such as filters.

  A solid charge transport layer such as a p-type semiconductor or a hole transport material may be used instead of the above liquid electrolyte and quasi-solid electrolyte. An organic hole transport material may be used as the solid charge transport layer. The hole transport layer is preferably a conductive polymer such as polythiophene, polyaniline, polypyrrole, and polysilane, and a spiro compound in which two rings share a central element having a tetrahedral structure such as C or Si, a triarylamine, etc. Aromatic amine derivatives, triphenylene derivatives, nitrogen-containing heterocyclic derivatives, liquid crystal cyano derivatives are exemplified.

  Since the redox couple becomes an electron carrier, a certain concentration is required. The preferred concentration is 0.01 mol / l or more in total, more preferably 0.1 mol / l, and particularly preferably 0.3 mol / l or more. The upper limit in this case is not particularly limited, but is usually about 5 mol / l.

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

（Ａ−１）０．１７ｇと（Ｂ−１）０．４０ｇを１−ブタノール１０ｍｌとトルエン１０ｍｌの混合溶媒中で混合し、６時間１２０℃に加熱下攪拌した。得られた結晶を吸引ろ過によりろ別し、シリカゲルカラムクロマトグラフィーによって精製して、前述のＳ−１３（０．１０ｇ）を調製した。
また以下の方法により、参考例の色素Ｒ−４を調製した。

4，４’−ビス［２−（５−ヘキシル−２−チエニル）ビニル］−２，２’−ビピリジン（０．３０ｇ、０．４９ｍｍｏｌ）とジクロロ（ｐ−シメン）ルテニウム（ＩＩ）二量体（０．１５ｇ、０．２４ｍｍｏｌ）のＤＭＦ２５ｍｌ溶液をマイクロ波（２００Ｗ）、窒素暗雰囲気下、６０℃で１０分間加熱した。続いて２，２’−ビピリジン−４，４’−ジカルボン酸（０．２４ｇ、０．９８ｍｍｏｌ）を添加し、１５０℃で１０分間加熱した。温度を１００℃に冷却し、チオシアン酸アンモニウム（１.６ｇ、水１０ｍｌの溶液）を加え、１２０℃で１０分間反応させた。温度を室温まで下げ、ＤＭＦを真空蒸留した。水１５０ｍｌを残留物に添加し、３０分間浸漬した。不溶物を集め、水とジエチルエーテルで洗浄した。粗生成物をＴＢＡＯＨ（水酸化テトラブチルアンモニウム）と共にメタノールに溶解し、メタノールを流出液として、ＳｅｐｈａｄｅｘＬＨ−２０カラムで精製した。主層の生成物を回収濃縮し、硝酸０．２Ｍを添加して沈殿物を得た。この生成物を集め、室温で真空乾燥後、０．６３ｇのルテニウム錯体（Ｒ−４）を得た.
1. Dye preparation

0.17 g of (A-1) and 0.40 g of (B-1) were mixed in a mixed solvent of 10 ml of 1-butanol and 10 ml of toluene and stirred while heating at 120 ° C. for 6 hours. The obtained crystals were separated by suction filtration and purified by silica gel column chromatography to prepare the aforementioned S-13 (0.10 g).
Moreover, the pigment | dye R-4 of the reference example was prepared with the following method.

4,4′-bis [2- (5-hexyl-2-thienyl) vinyl] -2,2′-bipyridine (0.30 g, 0.49 mmol) and dichloro (p-cymene) ruthenium (II) dimer A solution (0.15 g, 0.24 mmol) of DMF in 25 ml was heated at 60 ° C. for 10 minutes in a microwave (200 W) under nitrogen dark atmosphere. Subsequently, 2,2′-bipyridine-4,4′-dicarboxylic acid (0.24 g, 0.98 mmol) was added and heated at 150 ° C. for 10 minutes. The temperature was cooled to 100 ° C., ammonium thiocyanate (1.6 g, a solution of 10 ml of water) was added, and the mixture was reacted at 120 ° C. for 10 minutes. The temperature was lowered to room temperature and DMF was distilled in vacuo. 150 ml of water was added to the residue and immersed for 30 minutes. The insoluble material was collected and washed with water and diethyl ether. The crude product was dissolved in methanol together with TBAOH (tetrabutylammonium hydroxide), and purified with a Sephadex LH-20 column using methanol as the effluent. The product of the main layer was collected and concentrated, and 0.2M nitric acid was added to obtain a precipitate. This product was collected and vacuum dried at room temperature to obtain 0.63 g of ruthenium complex (R-4).

(Preparation of Exemplified Compound D-1-1a)
Exemplified dye D-1-1a was prepared according to the method of the following scheme.

(I) Preparation of Compound d-1-2 d-1-1 25 g, Pd (dba) 33.8 g, triphenylphosphine 8.6 g, copper iodide 2.5 g, 1-heptin 25.2 g were triethylamine 70 ml. The mixture was stirred in 50 ml of tetrahydrofuran at room temperature and stirred at 80 ° C. for 4.5 hours. After concentration, 26.4 g of compound d-1-2 was obtained by purification by column chromatography.
(Ii) Preparation of d-1-4 6.7 g of d-1-3 was dissolved in 200 ml of THF (terahydrofuran) at −15 ° C. in a nitrogen atmosphere, and separately prepared LDA (lithium diisopropylamide) was d- 2.5 equivalents of 1-3 were added dropwise and stirred for 75 minutes. Thereafter, a solution obtained by dissolving 15 g of d-1-2 in 30 ml of THF was dropped, and the mixture was stirred at 0 ° C. for 1 hour, and stirred at room temperature overnight. After concentration, 150 ml of water was added, liquid separation and extraction were performed with 150 ml of methylene chloride, the organic layer was washed with brine, and the organic layer was concentrated. The obtained crystal was recrystallized from methanol to obtain 18.9 g of d-1-4.

(Iii) Preparation of Compound d-1-5 13.2 g of d-1-4 and 1.7 g of PPTS (pyridinium paratoluenesulfonic acid) were added to 1000 ml of toluene, and the mixture was heated to reflux for 5 hours in a nitrogen atmosphere. After concentration, liquid separation was performed with saturated aqueous sodium hydrogen carbonate and methylene chloride, and the organic layer was concentrated. The obtained crystals were recrystallized from methanol and methylene chloride to obtain 11.7 g of d-1-5.
(Iv) Preparation of Exemplified Dye D-1-1a Compound d-1-5 4.0 g and d-1-6 2.2 g were added to DMF 60 ml and stirred at 70 ° C. for 4 hours. Thereafter, 2.1 g of d-1-7 was added and the mixture was heated and stirred at 160 ° C. for 3.5 hours. Thereafter, 19.0 g of ammonium thiocyanate was added and stirred at 130 ° C. for 5 hours. After concentration, 1.3 ml of water was added and filtered, and washed with diethyl ether. The crude product was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide) and purified with a Sephade XLH-20 column. The main layer fraction was collected and concentrated, and then 0.2 M nitric acid was added. The precipitate was filtered and washed with water and diethyl ether to obtain 600 mg of D-1-1b. The purified product was dissolved in a methanol solution, 1M nitric acid was added, the precipitate was filtered, and washed with water and diethyl ether to obtain 570 mg of D-1-1-1a.
The structure of the obtained compound D-1-1a was confirmed by NMR measurement.
¹ H-NMR (DMSO-d ₆ , 400 MHz): δ (ppm) in aromatic regions: 9.37 (1H, d), 9.11 (1H, d), 9.04 (1H, s), 8. 89 (2H), 8.74 (1H, s), 8.26 (1H, d), 8.10-7.98 (2H), 7.85-7.73 (2H), 7.60 (1H , D), 7.45-7.33 (2H), 7.33-7.12 (5H, m), 6.92 (1H, d)
About the obtained exemplary pigment | dye D-1-1a, it prepared so that the density | concentration of pigment | dye might be 8.5 micromol / l with an ethanol solvent, and when the spectral absorption measurement was performed, the absorption maximum wavelength was 568 nm.

(Preparation of Exemplified Dye D-1-21a)
In accordance with the method of the following scheme, d-2-4 was prepared, and Exemplified Dye D-1-21a was prepared in the same manner as Exemplified Dye D-1-1a below. About the obtained exemplary pigment | dye D-1-21a, when it prepared so that the density | concentration of pigment | dye might be set to 8.5 micromol / l with an ethanol solvent, and the spectral absorption measurement was performed, the absorption maximum wavelength was 570 nm.

( Preparation of Dye D-1-16a of Reference Example )
In accordance with the method of the following scheme, d-3-2 was prepared, and a dye D-1-16a of Reference Example was prepared in the same manner as the exemplified dye D-1-1a. About the obtained pigment | dye D-1-16a of the obtained reference example, when the density | concentration of the pigment | dye was prepared so that it might become 8.5 micromol / l with the ethanol solvent, and the spectral absorption measurement was performed, the absorption maximum wavelength was 574 nm.

( Preparation of Dye D-1-17a of Reference Example )
In accordance with the method of the following scheme, d-4-2 was prepared, and in the same manner as Exemplified Dye D-1-1a, Reference Example Dye D-1-17a was prepared. About the obtained pigment | dye D-1-17a of the reference example, it prepared so that the density | concentration of the pigment | dye might be 8.5 micromol / l with an ethanol solvent, and when the spectral absorption measurement was performed, the absorption maximum wavelength was 588 nm.

(Preparation of Exemplified Dye D-1-22a)
D-5-6 was prepared according to the method of the following scheme, and Exemplified Dye D-1-22a was prepared in the same manner as Exemplified Dye D-1-1a below. About the obtained exemplary pigment | dye D-1-22a, when it prepared so that the density | concentration of pigment | dye might be set to 8.5 micromol / l with an ethanol solvent, and the spectral absorption measurement was performed, the absorption maximum wavelength was 570 nm.

( Preparation of Reference Example D-1-23a)
In accordance with the method of the following scheme, d-6-3 was prepared, and then a dye D-1-23a of Reference Example was prepared in the same manner as the exemplified dye D-1-1a. About the obtained pigment | dye D-1-23a of the obtained reference example, when the density | concentration of the pigment | dye was prepared with an ethanol solvent so that it might become 8.5 micromol / l, and the spectral absorption measurement was performed, the absorption maximum wavelength was 571 nm.

(Preparation of Exemplified Dye D-1-24a)
In the preparation of the exemplified dye D-1-21a, D-1-24a was prepared by using the following d-7-1 instead of d-2-2. About the obtained exemplary pigment | dye D-1-24a, it prepared so that the density | concentration of the pigment | dye might be set to 8.5 micromol / l with the ethanol solvent, and when the spectral absorption measurement was performed, the absorption maximum wavelength was 574 nm.

( Preparation of Reference Example Dye D-8-1)
According to the method of the following scheme, Reference Example Dye D-8-1 was prepared in the same manner as Exemplified Dye D-1-1a. About the obtained pigment | dye D-8-1 of the reference example, it prepared so that the density | concentration of pigment | dye might be 8.5 micromol / l with an ethanol solvent, and when the spectral absorption measurement was performed, the absorption maximum wavelength was 580 nm.

The dye of the general formula (2) prepared by the above method is as follows.

[Experiment 1]
(Preparation of photoelectric conversion element)
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. Among these, anatase-type titanium oxide particles were sintered on one conductive film to produce a light receiving electrode. Thereafter, a dispersion containing 40:60 (mass ratio) of silica particles and rutile was applied and sintered on the light receiving electrode to form an insulating porous body. Next, a carbon electrode was formed as a counter electrode.

Next, the glass substrate on which the insulating porous body was formed was mixed with an ethanol solution of a dye described in Table 1 below (when there were two kinds of dyes, a mixed solution of 1 × 10 ⁻⁴ mol / l, when one kind was used) It was immersed in a single solution of the same concentration for 24 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 photoreceptor thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² . The coating amount of the dye was appropriately selected from the range of 0.1 to 10 mmol / m ² so as to show the optimum sensitization according to the kind of the dye.
As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / l) and iodine (0.1 mol / l) was used.

(Measurement of maximum absorption wavelength of dye)
The maximum absorption wavelength of the dye used was measured. The measurement was performed with a spectrophotometer (U-4100 (trade name), manufactured by Hitachi High-Tech), and the solution was tetrahydrofuran: ethanol = 1: 1 so that the dye concentration was 2 μM. The results are shown in Table 1.

(Measurement of photoelectric conversion efficiency)
Simulated sunlight that does not contain ultraviolet rays is generated by passing the light of a 500 W xenon lamp (made by Ushio) through an AM1.5G filter (made by Oriel) and a sharp cut filter (KenkoL-42 (trade name), made by Kenko). I let you. 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), manufactured by Keithley). Table 1 shows the results obtained by measuring the initial value of the conversion efficiency of the photoelectrochemical cell thus obtained. The durability after light irradiation was also evaluated in the same manner.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

表１からわかるように、一般式（１）の構造を有する色素と、一般式（２）の構造を有する色素を併用した場合は、一般式（１）の構造を有する色素単独又は一般式（２）の構造を有する色素単独の場合と比較して、合格レベルの変換効率の光電気化学電池が得られた。
実験１の比較例で使用した色素Ｒ−６は以下のものを表す。

As can be seen from Table 1, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, the dye having the structure of the general formula (1) alone or the general formula ( Compared to the case of the dye alone having the structure of 2), a photoelectrochemical cell having an acceptable conversion efficiency was obtained.
The dye R-6 used in the comparative example of Experiment 1 represents the following.

[Experiment 2]
An ITO film was produced on a glass substrate, and an FTO film was laminated thereon to produce a transparent conductive film. Then, a transparent electrode plate was obtained by forming an oxide semiconductor porous film on the transparent conductive film. And the photoelectrochemical cell was produced using the transparent electrode plate, and conversion efficiency was measured. The method is as follows (1)-(5).

(1) Preparation of raw material compound solution for ITO (indium / tin / oxide) film Indium (III) tetrahydrate 5.58 g and tin (II) chloride dihydrate 0.23 g were dissolved in 100 ml of ethanol. Thus, a raw material compound solution for the ITO film was obtained.

(2) Preparation of FTO (Fluorine Doped Tin Oxide) Film Raw Material Compound Solution 0.701 g of tin (IV) chloride pentahydrate was dissolved in 10 ml of ethanol, and 0.592 g of a saturated aqueous solution of ammonium fluoride was added thereto. This mixture was subjected to an ultrasonic cleaning machine for about 20 minutes and completely dissolved to obtain a raw material compound solution for an FTO film.

(3) Preparation of ITO / FTO transparent conductive film The surface of a heat-resistant glass substrate having a thickness of 2 mm was chemically washed and dried, and then this glass plate was placed in a reactor and heated with a heater. When the heating temperature of the heater reached 450 ° C., the raw material compound solution for ITO film obtained in (1) was adjusted from a nozzle with a diameter of 0.3 mm to a pressure of 0.06 MPa and a distance to the glass substrate of 400 mm, 25 Sprayed for a minute.
After spraying the raw material compound solution for ITO film, 2 minutes passed (ethanol was sprayed on the glass substrate surface during this period to suppress the rise of the substrate surface temperature), and the heating temperature of the heater became 530 ° C. Occasionally, the FTO membrane raw material compound solution obtained in (2) was sprayed for 2 minutes 30 seconds under the same conditions. As a result, a transparent electrode plate was obtained in which an ITO film having a thickness of 530 nm and an FTO film having a thickness of 170 nm were sequentially formed on the heat-resistant glass plate.
For comparison, similarly, a transparent electrode plate in which only a 530 nm thick ITO film is formed on a heat resistant glass substrate having a thickness of 2 mm and a transparent electrode plate in which only a 180 nm thick FTO film is formed are respectively provided. Produced.
These three types of transparent electrode plates were heated in a heating furnace at 450 ° C. for 2 hours.

(4) Production of photoelectrochemical cell Next, a photoelectrochemical cell having the structure shown in FIG. 2 of Japanese Patent No. 4260494 was produced using the above three types of transparent electrode plates.
The oxide semiconductor porous film 15 is formed by dispersing fine particles of titanium oxide having an average particle diameter of about 230 nm in acetonitrile to form a paste, applying the paste to the transparent electrode 11 to a thickness of 15 μm by a bar coating method, and drying 450 The oxide semiconductor porous film 15 was loaded with the dyes listed in Table 2 by baking at 1 ° C. for 1 hour.
Further, a conductive substrate in which an ITO film and an FTO film were laminated on a glass substrate was used for the counter electrode 16, and an electrolytic solution made of a non-aqueous solution of iodine / iodide was used for the electrolyte layer 17. The planar dimension of the photoelectrochemical cell was 25 mm × 25 mm.

(5) Evaluation of photoelectrochemical cell About this photoelectrochemical cell, simulated sunlight was irradiated by the method similar to Experiment 1, and conversion efficiency and durability were calculated | required. The results are shown in Table 2. The result is Sample No. The relative value when 9 is 1 is shown. Those having a relative value of the conversion efficiency of 0.6 or more were regarded as acceptable. Also, the rate of decrease in durability was 80% or more, ◎, 60% or more to less than 80% were evaluated as ◯, less than 60% were evaluated as △, and ○ and ◎ were evaluated as acceptable.

表２の結果からわかるように、導電層がＩＴＯ膜のみの場合やＦＴＯ膜のみの場合は、一般式（１）の構造を有する色素と、一般式（２）の構造を有する色素を併用した場合は、変換効率は低くなった。しかしそれでも色素を併用することにより、導電層がＩＴＯ膜のみの場合やＦＴＯ膜のみの場合でも、合格レベルの変換効率の光電気化学電池が得られた。

As can be seen from the results in Table 2, when the conductive layer is only an ITO film or only an FTO film, the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination. If so, the conversion efficiency was low. However, even when the dye was used in combination, a photoelectrochemical cell having an acceptable conversion efficiency was obtained even when the conductive layer was only an ITO film or only an FTO film.

[Experiment 3]
A collecting electrode was arranged on the FTO film to produce a photoelectrochemical cell, and the conversion efficiency was evaluated. Evaluation was made into two types, test cell (i) and test cell (iv) as follows.

(Test cell (i))
The surface of a 100 mm × 100 mm × 2 mm heat-resistant glass plate was chemically cleaned and dried, and then this glass substrate was placed in a reactor and heated with a heater, and then the FTO (fluorine-doped tin oxide) film used in Example II The raw material compound solution was sprayed from a nozzle having a diameter of 0.3 mm at a pressure of 0.06 MPa and a distance to the glass plate of 400 mm for 25 minutes to prepare a glass substrate with an FTO film.
On the surface, grooves having a depth of 5 μm were formed in a lattice circuit pattern by an etching method. After pattern formation by photolithography, etching was performed using hydrofluoric acid. A metal conductive layer (seed layer) was formed thereon by sputtering in order to enable plating formation, and a metal wiring layer 3 was further formed by additive plating. The metal wiring layer 3 was formed in a convex lens shape from the surface of the transparent substrate 2 to a height of 3 μm. The circuit width was 60 μm. From this, an FTO film having a thickness of 400 nm was formed as the shielding layer 5 by the SPD method to obtain an electrode substrate (i). Note that the cross-sectional shape of the electrode substrate (i) was as shown in FIG. 2 described in JP-A No. 2004-146425.

A titanium oxide dispersion having an average particle size of 25 nm was applied and dried on the electrode substrate (i), and heated and sintered at 450 ° C. for 1 hour. This was immersed in an ethanol solution of the dye shown in Table 3 for 40 minutes to carry the dye. It arrange | positioned facing a platinum sputter | spatter FTO board | substrate through a 50-micrometer-thick thermoplastic polyolefin resin sheet, the resin sheet part was heat-melted, and the bipolar plate was fixed.
A methoxyacetonitrile solution containing 0.5M iodide and 0.05M iodine as the main components was injected from the electrolyte solution inlet previously opened on the platinum sputter electrode side, and filled between the electrodes. It was. Furthermore, the peripheral part and the electrolyte solution injection port were sealed with an epoxy-based sealing resin, and a silver paste was applied to the current collecting terminal part to obtain a test cell (i). The photoelectric conversion characteristics of the test cell (i) were evaluated in the same manner as in Example I using AM1.5 simulated sunlight. The results are shown in Table 3.

(Test cell (iv))
A glass substrate with a 100 × 100 mm FTO film was prepared in the same manner as in the test cell (i). A metal wiring layer 3 (gold circuit) was formed on the FTO glass substrate by additive plating. The metal wiring layer 3 (gold circuit) was formed in a lattice shape on the substrate surface, and had a circuit width of 50 μm and a circuit thickness of 5 μm. On this surface, an FTO film having a thickness of 300 nm was formed as a shielding layer 5 by the SPD method to obtain a test cell (iv). When the cross section of the electrode substrate (iv) was confirmed using SEM-EDX, there was a sneaking in which seems to be caused by the bottom of the plating resist at the bottom of the wiring, and the shadow portion was not covered with FTO.
A test cell (iv) was produced in the same manner as the test cell (i) using the electrode substrate (iv). Simulated sunlight was irradiated in the same manner as in Experiment 1 to determine the conversion efficiency. The results are shown in Table 3.

(Evaluation of results)
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

表３より、本発明の色素の組み合わせを用いた場合は、試験セル（ｉ）の場合の変換効率は８％以上と、高い値を示した。試験セル（ｉｖ）を用いた場合でも、色素を単独で用いて試験セル（ｉ）を用いた場合よりも高い性能が得られ、いずれも合格レベルの変換効率を示した。

From Table 3, when the combination of the pigment | dye of this invention was used, the conversion efficiency in the case of test cell (i) showed a high value with 8% or more. Even when the test cell (iv) was used, higher performance was obtained than when the test cell (i) was used using the dye alone, and all showed acceptable conversion efficiency.

[Experiment 4]
Peroxotitanic acid and titanium oxide fine particles were prepared, and an oxide semiconductor film was prepared using them. Using this, a photoelectrochemical cell was produced and evaluated.
(Production of photoelectrochemical cell (A))
(1) Preparation of coating liquid (A1) for forming an oxide semiconductor film 5 g of titanium hydride is suspended in 1 liter of pure water, 400 g of a 5 mass% hydrogen peroxide solution is added over 30 minutes, and then 80 A solution of peroxotitanic acid was prepared by heating to ° C and dissolution. 90% by volume was taken from the total amount of this solution, adjusted to pH 9 by adding concentrated aqueous ammonia, placed in an autoclave, hydrothermally treated at 250 ° C. for 5 hours under saturated vapor pressure, and titania colloidal particles (A2) Was prepared. The obtained titania colloidal particles were anatase type titanium oxide having high crystallinity by X-ray diffraction.

Next, the obtained titania colloidal particles (A2) was concentrated to 10 wt%, the peroxotitanic acid solution were mixed, the titanium of the mixed solution TiO ₂ terms, TiO ₂ mass of 30 mass% Then, hydroxypropylcellulose was added as a film formation aid so that a coating solution for forming a semiconductor film (A1) was prepared.

(2) Production of Oxide Semiconductor Film (A3) Next, the coating liquid (A1) is applied on a transparent glass substrate on which fluorine-doped tin oxide is formed as an electrode layer, followed by natural drying, followed by a low-pressure mercury lamp. It was used to irradiate ultraviolet rays of 6000 mJ / cm ² to decompose the peroxo acid and harden the coating film. The coating film was heated at 300 ° C. for 30 minutes to decompose and anneal the hydroxypropyl cellulose to form an oxide semiconductor film (A3) on the glass substrate.

(3) Adsorption of dye to oxide semiconductor film (A3) Next, an ethanol solution having a concentration of 3 × 10 ⁻⁴ mol / liter of the dye of the present invention was prepared as a spectral sensitizing dye. This dye solution was applied onto the metal oxide semiconductor film (A3) with a 100 rpm spinner and dried. This coating and drying process was performed five times.

(4) Preparation of electrolyte solution In a mixed solvent with a volume ratio of acetonitrile and ethylene carbonate of 1: 5, tetrapropylammonium iodide is 0.46 mol / liter and iodine is 0.07 mol / liter. To prepare an electrolyte solution.

(5) Production of photoelectrochemical cell (A) The glass substrate on which the oxide semiconductor film (A3) adsorbed with the dye produced in (2) is formed is used as one electrode, and fluorine doped as the other electrode. The tin oxide was formed as an electrode. A transparent glass substrate carrying platinum thereon was disposed oppositely, the side surfaces were sealed with resin, and the electrolyte solution (4) was sealed between the electrodes. Further, the photoelectrochemical cell (A) was produced by connecting the electrodes with lead wires.

(6) Evaluation of photoelectrochemical cell (A) Simulated sunlight was irradiated in the same manner as in Experiment 1 to determine the conversion efficiency of the photoelectrochemical cell (A). The results are shown in Table 4.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

(Production of photoelectrochemical cell (B))
Oxide semiconductor film (except that it was irradiated with ultraviolet rays to decompose peroxo acid and harden the film, followed by Ar gas ion irradiation (Nisshin Electric Co., Ltd .: ion implantation apparatus, 200 eV irradiation for 10 hours) An oxide semiconductor film (B3) was formed in the same manner as in A3).

Similarly to the oxide semiconductor film (A3), the dye was adsorbed to the oxide semiconductor film (B3).
Thereafter, a photoelectrochemical cell (B) was prepared in the same manner as in Example 1, and the conversion efficiency was measured. The results are shown in Table 4.
(Evaluation of photoelectrochemical cell (B))
Simulated sunlight was irradiated in the same manner as in Experiment 1 to determine the conversion efficiency of the photoelectrochemical cell (A). The results are shown in Table 4.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

(Production of photoelectrochemical cell (C))
18.3 g of titanium tetrachloride was diluted with pure water to obtain an aqueous solution containing 1.0% by mass in terms of TiO ₂ . While stirring this aqueous solution, 15% by mass of aqueous ammonia was added to obtain a white slurry having a pH of 9.5. This slurry was washed by filtration to obtain a 10.2% by mass hydrated titanium oxide gel cake in terms of TiO ₂ . This cake was mixed with 400 g of a 5 mass% hydrogen peroxide solution, and then heated to 80 ° C. to dissolve to prepare a peroxotitanic acid solution. 90% by volume is taken from the total amount of this solution, and concentrated ammonia water is added to adjust the pH to 9, and the mixture is placed in an autoclave, hydrothermally treated at 250 ° C. for 5 hours under saturated vapor pressure, and titania colloid particles (C2 ) Was prepared.
Next, an oxide semiconductor film (C3) is formed in the same manner as the oxide semiconductor film (A3) using the peroxotitanic acid solution obtained above and titania colloidal particles (C2), and the metal oxide semiconductor film In the same manner as (A3), the dye of the present invention was adsorbed as a spectral sensitizing dye.
(Evaluation of photoelectrochemical cell (C))
Simulated sunlight was irradiated in the same manner as in Experiment 1 to determine the conversion efficiency of the photoelectrochemical cell (C). The results are shown in Table 4.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

(Production of photoelectrochemical cell (D))
18.3 g of titanium tetrachloride was diluted with pure water to obtain an aqueous solution containing 1.0% by mass in terms of TiO ₂ . While stirring this, 15% by mass of ammonia water was added to obtain a white slurry having a pH of 9.5. This slurry was filtered and washed, suspended in pure water to obtain a 0.6 mass% hydrated titanium oxide gel slurry as TiO ₂ , adjusted to pH 2 by adding hydrochloric acid thereto, put in an autoclave, and stirred at 180 ° C. for 5 hours. The titania colloidal particles (D2) were prepared by performing hydrothermal treatment under saturated vapor pressure for a period of time.

Next, titania colloidal particles (D2) are concentrated to 10% by mass, and hydroxypropylcellulose is added as a film forming aid so as to be 30% by mass in terms of TiO ₂ to form a semiconductor film. A coating solution was prepared. Next, the coating solution is applied onto a transparent glass substrate on which fluorine-doped tin oxide is formed as an electrode layer, dried naturally, and subsequently irradiated with 6000 mJ / cm ² of ultraviolet rays using a low-pressure mercury lamp to form a film. Cured. Furthermore, it decomposed | disassembled and annealed by heating for 30 minutes at 300 degreeC, and the oxide semiconductor film (D3) was formed.

Next, the dye of the present invention was adsorbed as a spectral sensitizing dye in the same manner as the oxide semiconductor film (A3). Then, the photoelectrochemical cell (D) was produced by the method similar to a photoelectric cell (A).
(Evaluation of photoelectrochemical cell (D))
Simulated sunlight was irradiated in the same manner as in Experiment 1 to determine the conversion efficiency of the photoelectrochemical cell (C). The results are shown in Table 4.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

表４より、本発明の色素の場合には、色素単独使用の場合よりも常に変換効率が高く、特に試験セル（Ａ）〜（Ｃ）を使用した場合には変換効率が高いことがわかった。

From Table 4, it was found that in the case of the dye of the present invention, the conversion efficiency was always higher than in the case of using the dye alone, particularly when the test cells (A) to (C) were used. .

[Example 5]
Titanium oxide was prepared by changing the method, an oxide semiconductor film was produced from the obtained titanium oxide, and a photoelectrochemical cell was evaluated.

(1) Preparation of titanium oxide by heat treatment method (titanium oxide 1 (blue kite type) etc.)
Using a commercially available anatase-type titanium oxide (trade name ST-01, manufactured by Ishihara Sangyo Co., Ltd.), this is heated to about 900 ° C. to be converted into a brookite-type titanium oxide, and further heated to about 1,200 ° C. Rutile type titanium oxide was used. Respectively, comparative titanium oxide 1 (anatase type), titanium oxide 1 (blue kite type), and comparative titanium oxide 2 (rutile type) are used.

(2) Synthesis of titanium oxide by wet method (titanium oxide 2 (blue kite type))
954 ml of distilled water is charged into a reaction vessel equipped with a reflux condenser and heated to 95 ° C. While maintaining the stirring speed at about 200 rpm, 46 ml of an aqueous solution of titanium tetrachloride (Ti content: 16.3 mass%, specific gravity 1.59, purity 99.9%) was added to this distilled water at a speed of about 5.0 ml / min. It was dripped at the reaction tank. At this time, care was taken not to lower the temperature of the reaction solution. As a result, the titanium tetrachloride concentration was 0.25 mol / liter (2% by mass in terms of titanium oxide). In the reaction vessel, the reaction solution started to become cloudy immediately after dropping, but kept at the same temperature. After the dropping was completed, the temperature was further raised and heated to the vicinity of the boiling point (104 ° C.). The reaction was terminated.

  The sol obtained by the reaction was filtered, and then powdered using a vacuum dryer at 60 ° C. As a result of quantitative analysis of this powder by X-ray diffractometry, the ratio of (peak intensity on the surface of blue kite type 121) / (peak intensity at the position where the three overlap) is 0.38, (rutile main peak intensity) / The ratio (peak intensity at the position where the three lines overlap) was 0.05. From these, the titanium oxide was crystallinity of about 70.0% by mass for the brookite type, about 1.2% by mass for the rutile type, and about 28.8% by mass for the anatase type. Further, when the fine particles were observed with a transmission electron microscope, the average particle diameter of the primary particles was 0.015 μm.

(Titanium oxide 3 (Blue Kite type))
An aqueous solution of titanium trichloride (Ti content: 28% by mass, specific gravity 1.5, purity 99.9%) was diluted with distilled water to obtain a solution having a concentration of 0.25 mol / L in terms of titanium concentration. At this time, it was ice-cooled so as not to increase the liquid temperature and kept at 50 ° C. or lower. Next, 500 ml of this solution was put into a reaction tank equipped with a reflux condenser, and ozone gas with a purity of 80% was bubbled from the ozone gas generator at 1 L / min while heating at 85 ° C. to carry out an oxidation reaction. This state was maintained for 2 hours to complete the reaction. The obtained sol was filtered and vacuum-dried to obtain a powder. As a result of quantitative analysis of this powder by X-ray diffractometry, the ratio of (peak intensity on the surface of blue kite type 121) / (peak intensity at the position where the three overlap) is 0.85, (rutile main peak intensity) / The ratio (peak intensity at the position where the three lines overlap) was 0. From these, the titanium dioxide was about 98% by mass for the blue kite type, 0% by mass for the rutile type, 0% by mass for the anatase type, and about 2% was amorphous. Further, when the fine particles were observed with a transmission electron microscope, the average particle diameter of the primary particles was 0.05 μm.

(Production and evaluation of photoelectrochemical cells)
A photoelectrochemical cell using the photoelectric conversion element having the structure shown in FIG. 1 described in JP-A No. 2000-340269 was produced by the following method using titanium oxides 1 to 3 prepared by the above method as a semiconductor.
A glass substrate was coated with fluorine-doped tin oxide to form a conductive transparent electrode. A paste using each titanium oxide particle as a raw material was formed on the electrode surface, applied to a thickness of 50 μm by a bar coating method, and then baked at 500 ° C. to form a thin layer having a thickness of about 20 μm.

Next, a 1 × 10 ⁻⁴ molar ethanol solution of the dye described in Table 5 is prepared, and the solution containing the dye represented by the general formula (1) is added for 2 hours, followed by the general formula (2). A glass substrate on which a thin layer of titanium oxide was formed was immersed in a solution containing a dye for 20 hours. As a result, these dyes were adsorbed onto a thin layer of titanium oxide.

  A photoelectric conversion element having a configuration shown in FIG. 1 of JP-A No. 2000-340269 was produced using an iodine salt of tetrapropylammonium as an electrolytic solution and an acetonitrile solution of lithium iodide and using platinum as a counter electrode. For photoelectric conversion, light from a 160 W high-pressure mercury lamp (the infrared part was cut by a filter) was applied to the above-mentioned element, and the conversion efficiency at that time was measured. The results are shown in Table 5.

(Evaluation of results)
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

  As can be seen from Table 5, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, the dye having the structure of the general formula (1) alone or the general formula ( Compared to the case of the dye alone having the structure of 2), a photoelectrochemical cell having an acceptable conversion efficiency was obtained.

[Experiment 6]
A paste in which semiconductor fine particles were dispersed was prepared using titanium oxides having different particle sizes. Using this, a photoelectrochemical cell was produced and its characteristics were evaluated.

[Preparation of paste]
(Paste 1)
A titania slurry was prepared by placing spherical TiO ₂ particles (anatase type, average particle size: 25 nm, hereinafter referred to as spherical TiO ₂ particles 1) in a nitric acid solution and stirring. Next, a cellulose binder as a thickener was added to the titania slurry and kneaded to prepare a paste.

(Paste 2)
A titania slurry was prepared by placing spherical TiO ₂ particles 1 and spherical TiO ₂ particles (anatase type, average particle size: 200 nm, hereinafter referred to as spherical TiO ₂ particles 2) in a nitric acid solution and stirring. Next, a cellulose binder as a thickener was added to the titania slurry and kneaded to prepare a paste (mass of TiO ₂ particles 1: mass of TiO ₂ particles 2 = 30:70).

(Paste 3)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase type, diameter: 100 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 1), the mass of the rod-like TiO ₂ particles 1: the mass of the paste 1 = 10: Ninety pastes were prepared.

(Paste 4)
The paste 1, a rod-shaped TiO ₂ particles 1 were mixed, the mass rod-shaped TiO ₂ particles 1: Paste 1 Mass = 30: 70 paste was prepared.

(Paste 5)
The paste 1, a rod-shaped TiO ₂ particles 1 were mixed, the mass rod-shaped TiO ₂ particles 1: Paste 1 Mass = 50: 50 paste was prepared.

(Paste 6)
The paste 1 is mixed with plate-like mica particles (diameter: 100 nm, aspect ratio: 6, hereinafter referred to as plate-like mica particles 1), and the mass of the plate-like mica particles 1: the mass of the paste 1 = 20: 80 paste. Was prepared.

(Paste 7)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 30 nm, aspect ratio: 6.3, hereinafter referred to as rod-like TiO ₂ particles 2), the mass of the rod-like TiO ₂ particles 2: the mass of the paste 1 = 30: 70 pastes were prepared.

(Paste 8)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 50 nm, aspect ratio: 6.1, hereinafter referred to as rod-like TiO ₂ particles 3), and the mass of the rod-like TiO ₂ particles 3: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 9)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 75 nm, aspect ratio: 5.8, hereinafter referred to as rod-like TiO ₂ particles 4), and the mass of the rod-like TiO ₂ particles 4: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 10)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 130 nm, aspect ratio: 5.2, hereinafter referred to as rod-like TiO ₂ particles 5), and the mass of the rod-like TiO ₂ particles 5: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 11)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 180 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 6), and the mass of the rod-like TiO ₂ particles 6: the mass of the paste 1 = 30: 70. A paste was prepared.

(Paste 12)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 240 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 7), and the mass of the rod-like TiO ₂ particles 7: the mass of the paste 1 = 30: 70. A paste was prepared.

(Paste 13)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 110 nm, aspect ratio: 4.1, hereinafter referred to as rod-like TiO ₂ particles 8), and the mass of the rod-like TiO ₂ particles 8: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 14)
The paste 1 is mixed with rod-shaped TiO ₂ particles (anatase, diameter: 105 nm, aspect ratio: 3.4, hereinafter referred to as rod-shaped TiO ₂ particles 9), and the mass of the rod-shaped TiO ₂ particles 9: the mass of the paste 1 = 30. : 70 paste was prepared.

(Photoelectrochemical cell 1)
A photoelectrode having the same configuration as the photoelectrode 12 shown in FIG. 5 of JP-A-2002-289274 is prepared by the following procedure, and further, using the photoelectrode, dye sensitization other than the photoelectrode is performed. A 10 × 10 mm scale photoelectrochemical cell 1 having the same configuration as the solar cell 20 was produced.

A transparent electrode in which a fluorine-doped SnO ₂ conductive film (film thickness: 500 nm) was formed on a glass substrate was prepared.
On the SnO ₂ conductive film, the paste 2 was screen-printed and then dried. Then, it baked on the conditions of 450 degreeC in the air. Further, by repeating the firing and the screen printing using a paste 4, the semiconductor electrodes (area of the light receiving surface of the same structure as the semiconductor electrode 2 shown in FIG. 5 of Patent Document on SnO ₂ conductive film; 10 mm × 10 mm, layer thickness: 10 μm, semiconductor layer thickness: 6 μm, light scattering layer thickness: 4 μm, content of rod-like TiO ₂ particles 1 contained in the light scattering layer; 30% by mass) for sensitization A photoelectrode containing no dye was prepared.

Next, the pigment | dye was made to adsorb | suck to a semiconductor electrode as follows. First, an absolute ethanol dehydrated with magnesium ethoxide was used as a solvent, and each of the dyes described in Table 6 was dissolved so as to have a concentration of 3 × 10 ⁻⁴ mol / L to prepare a dye solution. Next, the semiconductor electrode was immersed in this solution, whereby about 1.5 × 10 ⁻⁷ mol / cm ² of the dye was adsorbed to the semiconductor electrode in total, and the photoelectrode 10 was completed.

  Next, a platinum electrode (thickness of Pt thin film; 100 nm) having the same shape and size as the above-described photoelectrode as a counter electrode, and an iodine redox solution containing iodine and lithium iodide as an electrolyte E were prepared. Furthermore, a spacer S (trade name: “Surlin”) manufactured by DuPont having a shape corresponding to the size of the semiconductor electrode is prepared. As shown in FIG. 3 of JP-A-2002-289274, the photoelectrode 10 and The counter electrode CE and the spacer S were opposed to each other, and the above electrolyte was filled therein to complete the photoelectrochemical cell 1.

(Photoelectrochemical cell 2)
The photoelectrode 10 shown in FIG. 1 described in JP-A-2002-289274 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the semiconductor electrode was manufactured as follows. A photoelectrochemical cell 2 having the same configuration as that of the dye-sensitized solar cell 20 shown in FIG.

Paste 2 was used as a semiconductor layer forming paste. Then, paste 2 was screen-printed on the SnO ₂ conductive film and then dried. Then, it baked on the conditions of 450 degreeC in the air, and formed the semiconductor layer.

  Paste 3 was used as the innermost layer forming paste of the light scattering layer. The paste 5 was used as the outermost layer forming paste of the light scattering layer. Then, a light scattering layer was formed on the semiconductor layer in the same manner as in the photoelectrochemical cell 1.

Then, on the SnO ₂ conductive film, a semiconductor electrode having the same structure as the semiconductor electrode 2 shown in FIG. 1 described in JP-A-2002-289274 (area of light receiving surface; 10 mm × 10 mm, layer thickness: 10 μm, semiconductor layer) Layer thickness: 3 μm, innermost layer thickness: 4 μm, content of rod-like TiO ₂ particles 1 contained in the innermost layer; 10 mass%, outermost layer thickness: 3 μm, innermost layer The content ratio of the rod-like TiO ₂ particles 1 contained in 1; 50% by mass) was formed, and a photoelectrode containing no sensitizing dye was produced. Similarly to the photoelectrochemical cell 1, the photoelectrochemical cell 2 was completed by making the photoelectrode, the counter electrode CE, and the spacer S face each other and filling the above electrolyte therein.

(Photoelectrochemical cell 3)
According to the same procedure as that of the photoelectrochemical cell 1, except that the paste 1 was used as a semiconductor layer forming paste and the paste 4 was used as a light scattering layer forming paste in the production of a semiconductor electrode. 5 was produced, and a photoelectrochemical cell 3 having the same configuration as the photoelectrochemical cell 20 shown in FIG. 3 described in JP-A-2002-289274 was produced.
The semiconductor electrode has a light receiving surface area of 10 mm × 10 mm, a layer thickness of 10 μm, a semiconductor layer thickness of 5 μm, a light scattering layer thickness of 5 μm, and the rod-like TiO ₂ particles 1 contained in the light scattering layer. Content rate: 30% by mass.

(Photoelectrochemical cell 4)
In the production of the semiconductor electrode, the light shown in FIG. 5 was obtained by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 6 was used as the light scattering layer forming paste. A photoelectrode and a photoelectrochemical cell 4 having the same configuration as the electrode 10 and the photoelectrochemical cell 20 shown in FIG. 3 described in JP-A-2002-289274 were produced. The semiconductor electrode has a light receiving surface area: 10 mm × 10 mm, layer thickness: 10 μm, semiconductor layer thickness: 6.5 μm, light scattering layer thickness: 3.5 μm, plate-like contained in the light scattering layer The content of mica particles 1 was 20% by mass.

(Photoelectrochemical cell 5)
In the production of the semiconductor electrode, the photoelectrochemical cell 5 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 8 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 3 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 6)
In the production of the semiconductor electrode, the photoelectrochemical cell 6 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 9 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 4 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 7)
In the production of the semiconductor electrode, the photoelectrochemical cell 7 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 10 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 5 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 8)
In the production of the semiconductor electrode, the photoelectrochemical cell 8 was prepared by the same procedure as the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 11 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 6 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 9)
In the production of the semiconductor electrode, the photoelectrochemical cell 9 was prepared in the same procedure as the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 13 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 8 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 10)
In the production of the semiconductor electrode, the photoelectrochemical cell 10 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 14 was used as the light scattering layer forming paste. Produced. The content of the rod-like TiO ₂ particles 9 contained in the light scattering layer of the semiconductor electrode was 30% by mass.

(Photoelectrochemical cell 11)
Similar to the photoelectrochemical cell 1 except that a semiconductor electrode (light-receiving surface area: 10 mm × 10 mm, layer thickness: 10 μm) made of only the semiconductor layer using only the paste 2 was manufactured in the manufacture of the semiconductor electrode. The photoelectrochemical cell 11 was produced according to the procedure.

(Electrochemical battery 12)
In the production of the semiconductor electrode, the photoelectrode and the comparative photoelectricity were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 7 was used as the light scattering layer forming paste. A chemical battery 12 was produced. The content ratio of the rod-shaped TiO ₂ particles 2 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

[Testing and evaluation of characteristics]
About the photoelectrochemical cells 1-12, 1000 W / m < ² > pseudo-sunlight was irradiated from the xenon lamp which passed the AM1.5 filter using the solar simulator (the product made from WACOM, WXS-85H). The current-voltage characteristics were measured using an IV tester to determine the conversion efficiency. The results are shown in Table 6.
A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is ○, 8% or more and less than 6.5% is △, and less than 6.5% is ×, A conversion efficiency of 8% or more was accepted and a conversion efficiency of less than 8% was rejected.

表６からわかるように、一般式（１）の構造を有する色素と、一般式（２）の構造を有する色素を併用した場合は、一般式（１）の構造を有する色素単独又は一般式（２）の構造を有する色素単独の場合と比較して、合格レベルの変換効率の光電気化学電池が得られた。

As can be seen from Table 6, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, the dye having the structure of the general formula (1) alone or the general formula ( Compared to the case of the dye alone having the structure of 2), a photoelectrochemical cell having an acceptable conversion efficiency was obtained.

[Example 7]
A slurry obtained by adding metal alkoxide to metal oxide fine particles was applied to a conductive substrate, and then UV ozone irradiation, UV irradiation or drying was performed to produce an electrode. Then, the photoelectrochemical cell was produced and the conversion efficiency was measured.

(Metal oxide fine particles)
Titanium oxide was used as the metal oxide fine particles. As the titanium oxide, P25 powder (trade name, manufactured by Degussa) having a mass ratio of 30% rutile type and 70% anatase type and an average particle size of 25 nm was used.

(Pretreatment of metal oxide fine particle powder)
The metal oxide fine particles were previously heat-treated to remove surface organic substances and moisture. In the case of titanium oxide fine particles, the fine particles were heated in an oven at 450 ° C. in the atmosphere for 30 minutes.

(Measurement of water content in metal oxide fine particles)
When the moisture content contained in titanium oxide and P25 powder (trade name, manufactured by Degussa) stored in an environment of temperature 26 ° C. and humidity 72% is reduced by thermogravimetry and heated to 300 ° C. The amount of moisture desorbed was determined by Karl Fischer titration.

  When the amount of water desorbed when titanium oxide, P25 powder (trade name, manufactured by Degussa) was heated at 300 ° C. was quantified by Karl Fischer titration, 0.253 mg of water was contained in 0.1033 g of titanium oxide fine powder. It was included. That is, the fine titanium oxide powder contained about 2.5% by mass of water. It was heat-treated for 30 minutes, cooled and stored in a desiccator.

(Preparation of metal alkoxide paste)
The metal alkoxide that plays a role in bonding metal oxide fine particles includes titanium (IV) tetraisopropoxide (TTIP) as a titanium raw material, zirconium (IV) tetra n-propoxide as a zirconium raw material, and niobium as a niobium raw material. (V) Pentaethoxide (all manufactured by Aldrich) was used.

  The molar concentration ratio between the metal oxide fine particles and the metal alkoxide is appropriately adjusted according to the metal oxide fine particle diameter so that the amorphous layer generated by hydrolysis of the metal alkoxide is not excessively thick and the particles can be sufficiently bonded to each other. did. All metal alkoxides were 0.1M ethanol solutions. When mixing titanium oxide fine particles and titanium (IV) tetraisopropoxide (TTIP), 3.55 g of 0.1M TTIP solution was mixed with 1 g of titanium oxide fine particles. At this time, the titanium oxide concentration in the obtained paste was about 22% by mass, and the viscosity was appropriate for coating. Moreover, the titanium oxide, TTIP, and ethanol at this time were 1: 0.127: 3.42 by mass ratio, and 1: 0.036: 5.92 by molar ratio.

  Similarly, a mixed paste of titanium oxide fine particles and an alkoxide other than TTIP was prepared so that the fine particle concentration was 22% by mass. In the paste using zinc oxide and tin oxide fine particles, the content was 16% by mass. In the case of zinc oxide and tin oxide, the metal alkoxide solution was mixed at a ratio of 5.25 g to 1 g of the metal oxide fine particles.

  The metal oxide fine particles and the metal alkoxide solution were stirred for 2 hours with a magnetic stirrer in a sealed container to obtain a uniform paste. As a method for applying the paste to the conductive substrate, a doctor blade method, a screen printing method, a spray coating method, or the like can be used, and an appropriate paste viscosity is appropriately selected depending on the application method. Here, a method of applying simply with a glass rod (similar to the doctor blade method) was used. In this case, the concentration of the metal oxide fine particles giving an appropriate paste viscosity was approximately in the range of 5 to 30% by mass.

  In this experiment, the thickness of the amorphous metal oxide produced by the decomposition of the metal alkoxide was in the range of about 0.1 to 0.6 nm, and the thickness could be set to an appropriate range.

(Applying paste on conductive substrate and air-drying treatment)
Two adhesive tapes as spacers on a polyethylene terephthalate (PET) film substrate (20Ω / cm ² ) with tin-doped indium oxide (ITO) conductive film or a glass substrate (10Ω / cm ² ) with fluorine-doped tin oxide (FTO) conductive film The pastes were applied in parallel at regular intervals, and each paste prepared according to the above method was uniformly applied using a glass rod.
After applying the paste and before dye adsorption, a porous film was prepared by changing the conditions for the presence or absence of UV ozone treatment, UV irradiation treatment, or drying treatment.

(Drying process)
The film after application to the conductive substrate was air-dried in the atmosphere at room temperature for about 2 minutes. During this process, the metal alkoxide in the paste was hydrolyzed by moisture in the atmosphere, and amorphous titanium oxide, zirconium oxide, and niobium oxide were formed from Ti alkoxide, Zr alkoxide, and Nb alkoxide, respectively.
Since the produced amorphous metal oxide plays a role of adhering metal oxide fine particles and the film to the conductive substrate, a porous film excellent in mechanical strength and adhesion was obtained only by air drying.

(UV ozone treatment)
NL-UV253 UV ozone cleaner manufactured by Nippon Laser Electronics Co., Ltd. was used for UV ozone treatment. The UV light source was equipped with three 4.5 W mercury lamps having emission lines at 185 nm and 254 nm, and the sample was placed horizontally at a distance of about 6.5 cm from the light source. Ozone is generated by introducing an oxygen stream into the chamber. In this example, this UV ozone treatment was performed for 2 hours. Note that no decrease in the conductivity of the ITO film and the FTO film due to this UV ozone treatment was observed.

(UV treatment)
Similarly to the UV ozone treatment, the treatment was performed for 2 hours, except that the inside of the chamber was replaced with nitrogen. No decrease in the conductivity of the ITO film and FTO film due to the UV treatment was observed.

(Dye adsorption)
The dye of Table 7 was used for the dye, and a 0.3 mM ethanol mixed solution of each dye was prepared. In this experiment, the porous film produced by the above process was dried in an oven at 100 ° C. for 1 hour, then immersed in a sensitizing dye solution, and allowed to stand at room temperature for 1 hour to adsorb the dye on the titanium oxide surface. The sample after dye adsorption was washed with ethanol and air-dried.

(Production of photoelectrochemical cell and evaluation of battery characteristics)
A photoelectrochemical cell was fabricated by using a conductive substrate on which a porous film after dye adsorption was formed as a photoelectrode, and an ITO / PET film or FTO / glass counter electrode in which platinum fine particles were modified by sputtering. The effective area of the photoelectrode was about 0.2 cm ² . As the electrolyte solution, 3-methoxypropionitrile containing 0.5 M LiI, 0.05 M I ₂ and 0.5 M t-butylpyridine was introduced into the gap between the two electrodes by capillary action.

The battery performance was evaluated by photocurrent action spectrum measurement under irradiation with a constant number of photons (1016 cm ⁻² ) and IV measurement under irradiation with AM1.5 simulated sunlight (100 mW / cm ² ). A CEP-2000 type spectral sensitivity measuring device manufactured by Spectrometer Co., Ltd. was used for these measurements.
The conversion efficiency obtained is summarized in Table 7.

(Evaluation of results)
As a result, the conversion efficiency of 6% or more is ◎, 5.5% or more and less than 6% is ◯, 5. % Or more and less than 5.5% are indicated as Δ, and those less than 5% are indicated as x, and those with a conversion efficiency of 5.5% or more are regarded as acceptable.

  In Table 7, the columns of “UV ozone”, “UV”, and “dry” indicate the presence / absence of UV ozone treatment, UV irradiation treatment, and drying treatment after formation of the porous film and before sensitizing dye adsorption, respectively. The processed one is “◯”, and the unprocessed one is “×”.

The column of _“ Pretreatment of TiO ₂ ” in Table 7 indicates the presence or absence of pretreatment of titanium oxide fine particles (heat treatment in an oven at 450 ° C. for 30 minutes). Samples 6, 14, and 22 represent samples using a paste having a high TTIP concentration (titanium oxide: TTIP molar ratio of 1: 0.356). All other samples (samples 1 to 5, 7 to 13, 23, and 24) were made of a paste of titanium oxide: TTIP = 1: 0.0356.

  From the results shown in Table 7, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, the UV after the formation of the porous film and before the adsorption of the sensitizing dye It was found that the conversion efficiency of the photoelectrochemical cell was always higher than that when the dye was used alone, regardless of the presence of ozone treatment, UV irradiation treatment, and drying treatment, and conversion efficiency at a pass level was obtained.

[Experiment 8]
Using acetonitrile as a solvent, an electrolyte solution was prepared in which lithium iodide 0.1 mol / l, iodine 0.05 mol / l, and dimethylpropylimidazolium iodide 0.62 mol / l were dissolved. No. shown below. 1-No. 8 benzimidazole compounds were separately added and dissolved to a concentration of 0.5 mol / l.

No. 1-No. No. 8 benzimidazole compound electrolyte was dropped onto a porous titanium oxide semiconductor thin film (thickness: 15 μm) in which the dyes listed in Table 8 were supported on conductive glass. A frame type spacer (thickness: 25 μm) made of a polyethylene film was placed thereon, and this was covered with a platinum counter electrode to produce a photoelectric conversion element.
The obtained photoelectric conversion element was irradiated with light having an intensity of 100 mW / cm ^{2 using} a Xe lamp as a light source. Table 8 shows the open circuit voltage and photoelectric conversion efficiency obtained.

(Evaluation of results)
(I) The open circuit voltage is 7.0 V or more, ◎, 6.5 V or more and less than 7.0 V, ◯, 6.0 V or more and less than 6.5 V, Δ, or less than 6.0 V × It was displayed as 6.5V or more as the pass.
(Ii) A conversion efficiency of 8.5% or more is ◎, 8% or more and less than 8.5% is 、, 6.5% or more and less than 8% is △, and less than 6.5%. The case where the conversion efficiency was 8% or more was passed, and the conversion efficiency was less than 8% was rejected.
When the above (i) and (ii) were both acceptable, the overall evaluation was accepted.

表８の結果からわかるように、一般式（１）の構造を有する色素と、一般式（２）の構造を有する色素を併用した場合は、一般式（１）の構造を有する色素単独又は一般式（２）の構造を有する色素単独の場合と比較して、合格レベルの開放電圧及び変換効率の光電気化学電池を得ることができる。

As can be seen from the results of Table 8, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, the dye having the structure of the general formula (1) alone or in general Compared to the case of the dye alone having the structure of the formula (2), a photoelectrochemical cell having an acceptable open circuit voltage and conversion efficiency can be obtained.

[Experiment 9]
(Photoelectrochemical cell 1)
According to the following procedure, a photoelectrode having the same configuration as the photoelectrode 10 shown in FIG. 1 of JP-A No. 2004-152613 (however, the semiconductor electrode 2 has a two-layer structure) is manufactured. Except for using this photoelectrode, a photoelectrochemical cell having the same structure as the dye-sensitized solar cell 20 shown in FIG. 1 of JP-A No. 2004-152613 (the area of the light receiving surface F2 of the semiconductor electrode 2 is 1 cm). ² ) was produced. For each layer of the semiconductor electrode 2 having the two-layer structure, a layer disposed on the side close to the transparent electrode 1 is referred to as “first layer”, and a layer disposed on the side close to the porous body layer PS is referred to as “second layer”. The layer.

First, P25 powder having an average particle diameter of 25 nm (trade name, manufactured by Degussa), titanium oxide particles having a different particle diameter, and P200 powder (average particle diameter: 200 nm, product name, manufactured by Degussa) were used. And P200 are 15% by mass, and the mass ratio of P25 and P200 is P25: P200 = 30: 70, so that acetylacetone, ion-exchanged water, surfactant (manufactured by Tokyo Chemical Industry Co., Ltd.) , Trade name: “Triton-X”) and kneaded to prepare a slurry for forming a second layer (hereinafter referred to as “slurry 1”).
Next, the slurry for forming the first layer (P1 content: 15 mass%; hereinafter, “slurry” was prepared by the same preparation procedure as that of the slurry 1 except that only P25 was used without using P200. 2)) was prepared.

On the other hand, a transparent electrode (thickness: 1.1 mm) in which a fluorine-doped SnO ₂ conductive film (film thickness: 700 nm) was formed on a glass substrate (transparent conductive glass) was prepared. Then, the SnO ₂ conductive film, the slurry 2 described above was coated with Bakoda, then dried. Then, it baked for 30 minutes at 450 degreeC in air | atmosphere. In this way, the first layer of the semiconductor electrode 2 was formed on the transparent electrode.

Furthermore, the second layer was formed on the first layer by repeating the same application and firing as described above using the slurry 1. In this way, the semiconductor electrode 2 (light-receiving surface area; 1.0 cm ² , the total thickness of the first layer and the second layer: 10 μm (the thickness of the first layer: 3 μm, the first layer) on the SnO ₂ conductive film No. 2 layer thickness: 7 μm)), and a photoelectrode 10 containing no sensitizing dye was prepared.

Next, an ethanol solution of the dye described in Table 9 (concentration of each sensitizing dye; 3 × 10 ⁻⁴ mol / L) was prepared as the dye. The photoelectrode 10 was immersed in this solution and allowed to stand for 20 hours under a temperature condition of 80 ° C. As a result, a total of about 1.0 × 10 ⁻⁷ mol / cm ^{2 of} sensitizing dye was adsorbed inside the semiconductor electrode. Thereafter, in order to improve the open circuit voltage Voc, the semiconductor electrode after the adsorption of the ruthenium complex was immersed in an acetonitrile solution of 4-tert-butylpyridine for 15 minutes, and then dried in a nitrogen stream maintained at 25 ° C. 10 was completed. In Table 9, R-6 indicates that used in Comparative Example of Experiment 1.

  Next, a counter electrode CE having the same shape and size as the above photoelectrode was produced. First, an isopropanol solution of chloroplatinic acid hexahydrate was dropped on a transparent conductive glass, dried in air, and then baked at 450 ° C. for 30 minutes to obtain a platinum sintered counter electrode CE. The counter electrode CE was previously provided with a hole for injection of the electrolyte E (diameter 1 mm).

  Next, zinc iodide, 1,2-dimethyl-3-propylimidazolium iodide, iodine, and 4-tert-butylpyridine are dissolved in methoxyacetonitrile as a solvent to form a liquid electrolyte (iodide). Zinc concentration: 10 mmol / L, dimethylpropylimidazolium iodide concentration: 0.6 mol / L, iodine concentration: 0.05 mol / L, 4-tert-butylpyridine concentration: 1 mol / L).

Next, a spacer S (trade name: “HIMILAN”, ethylene / methacrylic acid random copolymer ionomer film) manufactured by Mitsui Dupont Polychemical Co., Ltd. having a shape matched to the size of the semiconductor electrode was prepared. As shown in FIG. 1 of Japanese Patent No. 152613, the photoelectrode and the counter electrode were opposed to each other via a spacer, and each was bonded by thermal welding to obtain a battery casing (no electrolyte filled).
Next, after injecting the liquid electrolyte into the housing from the hole of the counter electrode, the hole is closed with a member made of the same material as the spacer, and this member is thermally welded to the hole of the counter electrode to seal the hole. 1 was completed.

(Photoelectrochemical cell 2)
The photoelectrochemical cell 2 was produced in the same procedure and conditions as the photoelectrochemical cell 1 except that the concentration of zinc iodide in the liquid electrolyte was 50 mmol / L.

(Photoelectrochemical cell 3)
Comparative photoelectrochemistry was performed in the same procedure and conditions as in the photoelectrochemical cell 1 except that lithium iodide was added instead of zinc iodide in the liquid electrolyte, and the concentration of lithium iodide in the liquid electrolyte was 20 mmol / L. A battery 1 was produced.

(Comparative electrochemical cell 4)
Comparative photoelectrochemistry in the same procedure and conditions as in the photoelectrochemical cell 1 except that lithium iodide was added instead of zinc iodide in the liquid electrolyte, and the concentration of lithium iodide in the liquid electrolyte was 100 mmol / L. Battery 4 was produced.

(Examination and evaluation)
Conversion efficiency was measured about the sample using the photoelectrochemical cells 1-4 by the following procedures.
The battery characteristic evaluation test uses a solar simulator (trade name; “WXS-85-H type”, manufactured by Wacom), and the irradiation conditions of pseudo-sunlight from a xenon lamp light source through an AM filter (AM1.5), The measurement was performed under measurement conditions of 100 mW / cm ² (so-called “1Sun” irradiation conditions).

  About each photoelectrochemical cell, the current-voltage characteristic was measured at room temperature using the IV tester, and conversion efficiency was calculated | required from these. The obtained results are shown as “fresh” in Table 9 (1 Sun irradiation conditions). Table 9 also shows the results of a durability evaluation test after 300 hours of conversion efficiency under operating conditions of 60 ° C., 1 Sun irradiation and 10Ω load.

表９に示した結果から明らかなように、一般式（１）の構造を有する色素と、一般式（２）の構造を有する色素を併用した場合は、電解質にヨウ化亜鉛を添加した場合でも優れたものであることがわかった。

As is clear from the results shown in Table 9, when the dye having the structure of the general formula (1) and the dye having the structure of the general formula (2) are used in combination, even when zinc iodide is added to the electrolyte, It turned out to be excellent.

[Experiment 10]
1. Preparation of Titanium Dioxide Dispersion 15 g of titanium dioxide fine particles (Nippon Aerosil Co., Ltd., Degussa P-25), water 45 g, dispersant (Aldrich, Triron X −100) 1 g and 30 g of zirconia beads having a diameter of 0.5 mm (manufactured by Nikkato Co., Ltd.) were added, and dispersion treatment was performed at 1500 rpm for 2 hours using a sand grinder mill (manufactured by Imex). Zirconia beads were filtered off from the resulting dispersion. The average particle diameter of the titanium dioxide fine particles in the obtained dispersion was 2.5 μm. The particle size was measured with a master sizer manufactured by MALVERN.

2. Preparation of Titanium Oxide Fine Particle Layer (Electrode A) Adsorbed with Dye 20 mm × 20 mm conductive glass plate coated with fluorine-doped tin oxide (Asahi Glass Co., Ltd., TCO glass-U, surface resistance: about 30Ω / m ² ) was prepared, and an adhesive tape for spacers was applied to both ends (a portion having a width of 3 mm from the end) on the conductive layer side, and then the dispersion was applied onto the conductive layer using a glass rod. After application of the dispersion, the adhesive tape was peeled off and air-dried at room temperature for 1 day. Next, this semiconductor-coated glass plate was placed in an electric furnace (muffle furnace FP-32 type manufactured by Yamato Scientific Co., Ltd.) and baked at 450 ° C. for 30 minutes. The semiconductor coated glass plate was taken out and cooled, and then immersed in an ethanol solution of the dye shown in Table 10 (concentration: mixed solution of 1 × 10 ⁻⁴ mol / L each) for 3 hours. The semiconductor-coated glass plate on which the dye was adsorbed was immersed in 4-tert-butylpyridine for 15 minutes, washed with ethanol, and air dried. The thickness of the dye-sensitized titanium oxide fine particle layer thus obtained was 10 μm, and the coating amount of the titanium oxide fine particles was 20 g / m ² . Moreover, the adsorption amount of the pigment | dye was in the range of 0.1-10 mmol / m < ² > according to the kind.

3. Production of Photoelectrochemical Battery As a solvent, a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 was used. Iodine and iodine salt of 1-methyl-3-hexylimidazolium as an electrolyte salt are added to this solvent to prepare a solution containing 0.05 mol / L iodine at an electrolyte salt concentration of 0.5 mol / L. did. 10 parts by mass of the nitrogen-containing polymer compound (1-1) was added to 100 parts by mass of this solution. Furthermore, 0.1 mol of an electrophile (2-6) for reactive nitrogen atoms of the nitrogen-containing polymer compound was mixed to obtain a uniform reaction solution.

On the other hand, on the dye-sensitized titanium oxide fine particle layer formed on the conductive glass plate, the platinum thin film side of the counter electrode made of a glass plate on which platinum is vapor-deposited through a spacer is placed. A glass plate was fixed. The open end of the obtained assembly was immersed in the electrolyte solution, and the reaction solution was infiltrated into the dye-sensitized titanium oxide fine particle layer by capillary action.
Subsequently, it heated at 80 degreeC for 30 minutes, and the crosslinking reaction was performed. Thus, as shown in FIG. 2 of JP 2000-323190 A, the dye-sensitized titanium oxide fine particle layer 20, the electrolyte layer 30, the platinum thin film 42, and the glass are formed on the conductive layer 12 of the conductive glass plate 10. A photoelectrochemical cell 1-1 (sample No. 1) of the present invention in which the counter electrode 40 composed of the plate 41 was sequentially laminated was obtained.
Further, by repeating the above process except that the combination of the composition of the dye and the electrolyte composition is changed as shown in Table 10, photoelectrochemical cells 1-2, 1- having different photosensitive layers 20 and / or charge transfer layers 30 are obtained. 3, 1-4 were obtained.

4). Production of photoelectrochemical cells A and B (1) Photoelectrochemical cell A
An electrode A (20 mm × 20 mm) composed of a titanium oxide fine particle layer dye-sensitized with the dye of the present invention as described above was superimposed on a platinum-deposited glass plate of the same size via a spacer. Next, using a capillary phenomenon in the gap between both glass plates, an electrolytic solution (0.05 mol / L of iodine using a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 as a solvent, lithium iodide 0) .5 mol / L solution) was infiltrated to produce photoelectrochemical cell A-1. Photoelectrochemical cells A-2, A-3, and A-4 were obtained by repeating the above steps except that the dye was changed as shown in Table 10.

(2) Photoelectrochemical cell B (electrolyte described in JP-A-9-27352)
The electrolytic solution was applied and impregnated on the electrode A (20 mm × 20 mm) composed of the titanium oxide fine particle layer dye-sensitized with the dye of the present invention as described above. The electrolyte was 1 g of hexaethylene glycol methacrylate (manufactured by Nippon Oil & Fats Chemical Co., Ltd., Bremer PE-350), 1 g of ethylene glycol, and 2-hydroxy-2-methyl-1-phenyl-propane as a polymerization initiator. It was obtained by dissolving 500 mg of lithium iodide in a mixed solution containing 20 mg of -1-one (manufactured by Ciba Geigy Japan, Darocur 1173) and vacuum degassing for 10 minutes. Next, the porous titanium oxide layer impregnated with the mixed solution is placed under a reduced pressure to remove bubbles in the porous titanium oxide layer, promote penetration of the monomer, and then polymerize by irradiation with ultraviolet light. A uniform gel of the compound was filled into the fine pores of the porous titanium oxide layer. The product thus obtained was exposed to an iodine atmosphere for 30 minutes to diffuse iodine in the polymer compound, and then a platinum-deposited glass plate was overlaid to obtain a photoelectrochemical cell B-1. Photoelectrochemical cells B-2, B-3, and B-4 were obtained by repeating the above steps except that the dye was changed as shown in Table 10.

5. Measurement of photoelectric conversion efficiency Simulated sun which does not contain ultraviolet rays by passing light of 500W xenon lamp (made by USHIO INC.) Through AM1.5 filter (made by Oriel) and sharp cut filter (Kenko L-42) It was light. The light intensity was 89 mW / cm ² .

（備考）
（１）色素の記号は本文中に記載のとおりである。また、色素Ｓ−１００としては上記の化合物を用いた。
（２）窒素含有高分子１−１は以下の化合物を示す。

（３）求電子剤

表１０からわかるように、本発明の条件は色素を各々単独で用いた場合に比べ３００時間経過後の変換効率低下が小さく、高い耐久性を示すことがわかった。
Alligator clips were connected to the conductive glass plate 10 and the platinum-deposited glass plate 40 of the above-described photoelectrochemical cell, and each alligator clip was connected to a current-voltage measuring device (Keutley SMU238 type). This was irradiated with simulated sunlight from the conductive glass plate 10 side, and the generated electricity was measured with a current-voltage measuring device. Table 10 summarizes the initial value (fresh) of the conversion efficiency (η) of the photoelectrochemical cell determined in this way and the rate of decrease in conversion efficiency after 300 hours of continuous irradiation.

(Remarks)
(1) Symbols of pigments are as described in the text. Moreover, said compound was used as pigment | dye S-100.
(2) Nitrogen-containing polymer 1-1 represents the following compound.

(3) Electrophile

As can be seen from Table 10, it was found that the conditions of the present invention showed a high durability since the decrease in conversion efficiency after 300 hours was smaller than when the dyes were used alone.

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

Claims (11)

A photoelectric conversion element having a laminated structure including a photoconductor having a semiconductor fine particle layer having a dye adsorbed on a conductive support, a charge transfer body, and a counter electrode, wherein the dye is represented by the following general formula (1) The photoelectric conversion element characterized by containing at least 1 sort (s) of the pigment | dye which consists of a compound which consists of, and at least 1 sort (s) of the pigment | dye which consists of a compound represented by following General formula (2).

[In the general formula (1), Q and Table tetravalent benzene ring group, a C ^R 1 ^{R 2 X 1} and X ² are each independently. Here, R ¹ and R ² each independently represents an aliphatic group . R and R ′ each independently represents an aliphatic group . P ¹ and P ² each independently represent a group represented by the following general formula (8) . W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formula (8), V ¹ represents a carboxy group or a salt thereof, or a group in which two V ¹ are bonded to each other to form a benzene ring. n represents an integer of 0 to 2, and when n is 2, V ¹ may be the same or different.
Y represents C (R ^b ) R ^c . R ^b and R ^c represent an aliphatic group and may be the same or different.
Z represents an aliphatic group and may be substituted with a carboxy group or a 4-carboxyphenyl group.
R ⁶ and R ⁸ each independently represents a hydrogen atom or an aliphatic group.
R ⁷ represents an oxygen atom or a group represented by any one of the following general formulas (12) to (14). ]

[In General Formulas (12) to (14), Rf represents a hydrogen atom or an aliphatic group. ]

M (LL ¹ ) m ₁ (LL ² ) m ₂ (X) m ₃ · CI General formula (2)

[In one general formula (2), M represents Ru, LL ¹ represents a bidentate ligand shown by the following formula (5-3), LL ² in the following general formula (4) Table Represents a bidentate ligand.
X represents a Chi Oshianeto group, isothiocyanate group, ligand of monodentate coordinating with a group selected from cyanate group and an isocyanate group or Ranaru group.
m ₁ represents 1 . m ₂ represents 1 .
m ₃ represents 2 .
CI represents a counter ion in the general formula ( 2 ) when a counter ion is necessary to neutralize the charge. ]

[And have contact with one general formula (5-3), each ^{R 9} and ^{R 10} are independently carboxy sheet group, sul ho group, hydroxy sheet group, hydroxamic acid group, a phosphoryl group properly the phosphonyl group or their Represents the salt. R ¹¹ and ^{R 12} is to display the substituents independently. a 1 and a2 will table a 0, b 1 and b2 are to table a 0. n is to Table 1. R ⁵³ and R ⁵⁴ represent an alkynyl group or an aryl group. ]

[In the general formula (4), Za, are each Zb and Zc independently represents a non-metallic atomic group which can form a pyridine ring, having acidic groups selected independently carboxy group and a salt thereof It may be. c represents 0 . ] The photoelectric conversion device according to claim 1, before Symbol group you express one general formula (8) is characterized by being represented by the following general formula (10).

[In General Formula ^(10), V 1, n, Z and Y have the same meanings as in the formula (8). ] The photoelectric conversion device according to claim 1, wherein ^{R 7} in the general formula (8), and wherein the pre-SL is a group represented by the general formula (12) or (13). The photoelectric conversion device according to claim 1 or 3 wherein R ⁷ in the general formula (8), characterized in that it is a group represented by the following general formula (16).

Wherein Y is C _{(CH 3) 2,} wherein Z is a photoelectric conversion device according to any one of claims 1 to 4, wherein the aliphatic group having 5 to 18 carbon atoms. Wherein Y is C _{(CH 3) 2,} wherein Z is either _{CH 3, C 2 H 5,} C 3 H 7 or claims 1 to 4, characterized in that it is a _CH 2 _CH 2 COOH the photoelectric conversion device according to (1). Wherein V ¹ is, photoelectric conversion device according to any one of claims 1 to 6, characterized in that a carboxy group or a salt thereof. Wherein V ¹ is, 5 - carboxy sheet group and 4,5-benzene ring selected from the group consisting of the condensation of claims 1 to 6, characterized in that at least one of any one Photoelectric conversion element. Wherein Z is an aliphatic group substituted with 4-carboxyphenyl group, wherein V ¹ is, photoelectric according to any one of claims 1 to 4, characterized in that a carboxy group or a salt thereof Conversion element. The photoelectric conversion element of any one two of claims 1-9, characterized in that said semiconductor fine particles are titanium oxide particles. A photoelectrochemical cell comprising the photoelectric conversion device according to any one of claims 1 to 10 .

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