JP5816111B2 - Metal complex dye composition, photoelectric conversion element and photoelectrochemical cell - Google Patents

Description

  The present invention relates to a metal complex dye composition having high solubility in a solvent, a photoelectric conversion element and a photoelectrochemical cell having high photoelectric conversion efficiency.

  Photoelectric conversion elements are used in various optical sensors, copying machines, photoelectrochemical cells (for example, 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. In addition, a photoelectric conversion element using an inexpensive organic dye as a sensitizer has been reported. However, it is not sufficient to obtain a photoelectric conversion element with high conversion efficiency.

  Therefore, a technique for improving the photoelectric conversion efficiency by adsorbing a photosensitizing dye having a specific structure to semiconductor fine particles has been proposed (see, for example, Patent Documents 2 and 3). However, since the photosensitizing dyes (pure products) described in Patent Documents 2 and 3 have low solubility in a solvent, the amount of the dye adsorbed on the semiconductor fine particles is insufficient under certain conditions, which is sufficient in terms of photoelectric conversion efficiency. However, it cannot be said from the viewpoint of productivity that the amount of the dye used is large or a long time is required for dissolution.

US Pat. No. 5,463,057 Japanese Patent No. 4576494 JP 2001-291534 A

  An object of the present invention is to provide a metal complex dye composition having high solubility in a solvent, a photoelectric conversion element and a photoelectrochemical cell having high photoelectric conversion efficiency. Moreover, the subject of this invention is providing the manufacturing method of a metal complex pigment | dye with high solubility with respect to a solvent.

  As a result of intensive studies, the present inventors have been able to improve the adsorption amount of the dye to the semiconductor fine particles because the metal complex dye containing a specific ligand has high solubility in a solvent. It has been found that a photoelectric conversion element and a photoelectrochemical cell having high efficiency can be provided. The present invention has been made based on this finding.

According to the present invention, the following means are provided.
<1> a metal complex dye represented by the following general formula (1), a metal complex dye represented by the following general formula (5) and / or a metal complex dye represented by the following general formula (6),
The content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). 5-5% of metal complex dye composition characterized by the above-mentioned.
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) ₂ · (CI ¹ ) _{m 3} General formula (1)
[In General Formula (1), M ¹ represents a metal atom, LL ¹ is a bidentate ligand represented by the following General Formula (2), and LL ² is represented by the following General Formula (3). This is a bidentate ligand.

  m1 represents 1. m2 represents 1.

Z ¹ represents a ligand and is at least one selected from an isothiocyanato group, an isocyanato group and an isoselenocyanato group.
CI ¹ represents a counter ion when a counter ion is necessary to neutralize the charge, and m3 is an integer of 0 or more. ]

［ 一般式（２）中、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は独立して、酸性基若しくはその塩又は水素原子を表し、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は同じでも異なっていてもよい。ただし、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４の少なくとも一つは酸性基又はその塩である。］

In General formula ^{(2), R} 11 ~R ¹⁴ and ^R 21 ^{to R 24} independently represent an acidic group or a salt thereof, or a hydrogen ^atom, R 11 ^{to R 14} and ^R 21 ^{to R 24} are the same as or different from each other It may be. However, at least one of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ is an acidic group or a salt thereof. ]

［ 一般式（３）中、ｎ１、ｎ２は独立して０〜３の整数を表し、Ｙ^１、Ｙ^２は独立して水素原子又は下記一般式（４）で表されるヘテロアリール基を表す。ただし、Ａｒ^１及びＡｒ^２は独立して下記一般式（４）で表されるヘテロアリール基を表す。］

[In General Formula (3), n1 and n2 independently represent an integer of 0 to 3, Y ¹ and Y ² independently represent a hydrogen atom or a heteroaryl group represented by the following General Formula (4). . However, Ar ¹ and Ar ² independently represent a heteroaryl group represented by the following general formula (4). ]

[In General Formula (4), R ^{31 to} R ³³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and at least one of R ^{31 to} R ³³ represents an alkyl group, an alkoxy group, or an alkynyl group. It is a group. X is a sulfur atom, an oxygen atom, a selenium atom or NR ⁴ , and R ⁴ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ]

M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) (CN) · (CI ¹ ) _{m 3} General formula (5)
[In General Formula (5), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ]

M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (CN) _2. (CI ¹ ) _{m 3} General formula (6)
[In General Formula (6), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ]

［ 一般式（７）中、Ｒ^４１〜Ｒ^４３及びＲ^５１〜Ｒ^５３は、独立に水素原子、アルキル基、アルコキシ基又はアルキニル基を表す。Ｒ^４１〜Ｒ^４３のうち少なくとも１つは、アルキル基、アルコキシ基又はアルキニル基である。Ｒ^５１〜Ｒ^５３のうち少なくとも１つは、アルキル基、アルコキシ基又はアルキニル基である。Ｘ^１及びＸ^２はそれぞれ独立に、硫黄原子、酸素原子、セレン原子又はＮＲ^７であり、Ｒ^７は、水素原子、アルキル基、アリール基又はヘテロ環基である。］
＜３＞前記一般式（７）におけるＸ^１及びＸ^２が硫黄原子であることを特徴とする＜２＞記載の金属錯体色素組成物。
＜４＞前記一般式（１）で表される金属錯体色素が下記一般式（８）で表されることを特徴とする＜１＞〜＜３＞のいずれか１項記載の金属錯体色素組成物。 <2> The metal complex dye composition according to <1>, wherein LL ² is represented by the following general formula (7) in the general formula (1).

[In the general formula ^{(7), R} 41 ~R ⁴³ and ^R 51 ^{to R 53} are independently a hydrogen atom, an alkyl group, an alkoxy group or an alkynyl group. At least one of R ^{41 to} R ⁴³ is an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{51 to} R ⁵³ is an alkyl group, an alkoxy group, or an alkynyl group. X ¹ and X ² are each independently a sulfur atom, an oxygen atom, a selenium atom or NR ⁷ , and R ⁷ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ]
<3> The metal complex dye composition according to <2>, wherein X ¹ and X ² in the general formula (7) are sulfur atoms.
<4> The metal complex dye composition according to any one of <1> to <3>, wherein the metal complex dye represented by the general formula (1) is represented by the following general formula (8): object.

［ 一般式（８）中、Ｒ^６１、Ｒ^６２は独立にアルキル基、アルコキシ基又はアルキニル基を表し、Ａ^１、Ａ^２は独立してカルボキシル基又はその塩を表す。］
＜５＞前記一般式（５）で表される金属錯体色素が下記一般式（９）で表され、前記一般式（６）で表される金属錯体色素が下記一般式（１０）で表されることを特徴とする＜１＞〜＜４＞のいずれか１項記載の金属錯体色素組成物。

In General formula ^{(8), R 61, R} 62 represents an alkyl group, an alkoxy group or an alkynyl group ^{independently,} A 1, ^{A 2} represents a carboxyl group or a salt thereof independently. ]
<5> The metal complex dye represented by the general formula (5) is represented by the following general formula (9), and the metal complex dye represented by the general formula (6) is represented by the following general formula (10). <1>-<4> The metal complex dye composition according to any one of <1> to <4>.

［ 一般式（９）中、Ｒ^７１及びＲ^７２は独立にアルキル基、アルコキシ基又はアルキニル基を表し、Ａ^５、Ａ^６は独立してカルボキシル基又はその塩を表す。
一般式（１０）中、Ｒ^７３及びＲ^７４は独立にアルキル基、アルコキシ基又はアルキニル基を表し、Ａ^７、Ａ^８は独立してカルボキシル基又はその塩である。］
＜６＞前記一般式（５）で表される金属錯体色素が下記一般式（１１）で表され、前記一般式（６）で表される金属錯体色素が下記一般式（１２）で表されることを特徴とする＜１＞〜＜５＞のいずれか１項記載の金属錯体色素組成物。

[In General Formula (9), R ⁷¹ and R ⁷² independently represent an alkyl group, an alkoxy group, or an alkynyl group, and A ⁵ and A ⁶ independently represent a carboxyl group or a salt thereof.
In general formula (10), R ⁷³ and R ⁷⁴ independently represent an alkyl group, an alkoxy group or an alkynyl group, and A ⁷ and A ⁸ are each independently a carboxyl group or a salt thereof. ]
<6> The metal complex dye represented by the general formula (5) is represented by the following general formula (11), and the metal complex dye represented by the general formula (6) is represented by the following general formula (12). <1>-<5> The metal complex dye composition according to any one of <1> to <5>.

［ 一般式（１１）及び一般式（１２）中、Ｒ^８１〜Ｒ^８４は独立にアルキニル基を表す。Ａ^１３〜Ａ^１６は独立してカルボキシル基又はその塩を表す。］
＜７＞＜１＞〜＜６＞のいずれか１項記載の金属錯体色素組成物を増感色素として用いることを特徴とする光電変換素子。
＜８＞＜７＞に記載の光電変換素子を備えることを特徴とする光電気化学電池。

[In general formula (11) and general formula (12), R < ⁸¹ > -R < ⁸⁴ > represents an alkynyl group independently. A ^{13 to} A ¹⁶ independently represent a carboxyl group or a salt thereof. ]
<7> A photoelectric conversion element using the metal complex dye composition according to any one of <1> to <6> as a sensitizing dye.
<8> A photoelectrochemical cell comprising the photoelectric conversion element according to <7>.

  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 manufactured by this invention.

  As a result of intensive studies, the present inventors have been able to improve the adsorption amount of the dye to the semiconductor fine particles because the metal complex dye containing a specific ligand has high solubility in a solvent. It has been found that a photoelectric conversion element and a photoelectrochemical cell having high efficiency can be provided. The present invention has been made based on this finding.

  A preferred embodiment of the photoelectric conversion element of the present invention will be described with reference to the schematic cross-sectional view of FIG.

  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 photoreceptor layer 2 is composed of a porous semiconductor layer composed of a layer of semiconductor fine particles 22 to which a dye described later is adsorbed. This dye may be partially dissociated in the electrolyte. The photoreceptor layer 2 is designed according to the purpose and has a multilayer structure.

  As described above, since the photosensitive layer 2 includes the semiconductor fine particles 22 on which a specific dye is adsorbed, the light receiving sensitivity is high, and when used as the photoelectrochemical cell 100, high photoelectric conversion efficiency can be obtained. Furthermore, it has high durability.

(Metal complex dye composition)
The metal complex dye composition of the present invention is represented by a metal complex dye represented by the following general formula (1), a metal complex dye represented by the following general formula (5) and / or the following general formula (6). A metal complex dye
The content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). 5 to 5%.
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) ₂ · (CI ¹ ) _{m 3} General formula (1)
[In General Formula (1), M ¹ represents a metal atom, LL ¹ is a bidentate ligand represented by the following General Formula (2), and LL ² is represented by the following General Formula (3). This is a bidentate ligand.

  m1 and m2 are both 1. m3 is an integer of 0 or more.

Z ¹ represents a ligand and is at least one selected from an isothiocyanato group, an isocyanato group and an isoselenocyanato group. Z ¹ may be the same or different, but is preferably the same.
CI ¹ represents a counter ion when a counter ion is required to neutralize the charge. ]

［ 一般式（２）中、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は独立して、酸性基若しくはその塩又は水素原子を表し、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は同じでも異なっていてもよい。ただし、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４のうち少なくとも一つは酸性基又はその塩である。］

In General formula ^{(2), R} 11 ~R ¹⁴ and ^R 21 ^{to R 24} independently represent an acidic group or a salt thereof, or a hydrogen ^atom, R 11 ^{to R 14} and ^R 21 ^{to R 24} are the same as or different from each other It may be. However, at least one of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ is an acidic group or a salt thereof. ]

［ 一般式（３）中、ｎ１、ｎ２は独立して０〜３の整数を表し、Ｙ^１、Ｙ^２は独立して水素原子又は下記一般式（４）で表されるヘテロアリール基を表す。Ａｒ１及びＡｒ２は独立して下記一般式（４）で表されるヘテロアリール基を表す。］

[In General Formula (3), n1 and n2 independently represent an integer of 0 to 3, Y ¹ and Y ² independently represent a hydrogen atom or a heteroaryl group represented by the following General Formula (4). . Ar1 and Ar2 independently represent a heteroaryl group represented by the following general formula (4). ]

[In General Formula (4), R ^{31 to} R ³³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and at least one of R ^{31 to} R ³³ represents an alkyl group, an alkoxy group, or an alkynyl group. It is a group. X is a sulfur atom, an oxygen atom, a selenium atom or NR ⁴ , and R ⁴ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ]

M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) (CN) · (CI ¹ ) _{m 3} General formula (5)
[In General Formula (5), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ]

M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (CN) _2. (CI ¹ ) _{m 3} General formula (6)
[In General Formula (6), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ]

(A) Metal complex dye represented by general formula (1) (A1) Metal atom M ¹
M ¹ represents a metal atom. M ¹ 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 Zn. Particularly preferred is Ru, OsFe or Cu, and most preferred is Ru. Of Ru, divalent Ru is preferable.

(A2) Ligand LL ¹
The ligand LL ¹ is a bidentate represented by the following general formula (2). M1 representing the number of ligands LL ¹ is 1.

R < ¹¹ > -R < ¹⁴ > and R < ²¹ > -R < ²⁴ > in General formula (2) represent an acidic group or its salt, or a hydrogen atom independently, R < ¹¹ > -R < ¹⁴ > and R < ²¹ > -R < ²⁴ > are the same or different. May be. Examples of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ include a hydrogen atom, an acidic group (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). For example, —CONHOH, —CONCH ₃ OH, etc.), phosphoryl group (eg, —OP (O) (OH) ₂ etc.) or phosphonyl group (eg, —P (O) (OH) ₂ etc.) or a salt thereof. Can be mentioned. The acidic group may be bonded via a linking group, and those having an acidic group such as a carboxyl group, a sulfonic acid group, a hydroxyl group, or a hydroxamic acid group bonded via the linking group are also included in the acidic group. At least one of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ is an acidic group or a salt thereof. When R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ represent an acidic group, from the viewpoint of electron injection, the acidic group is preferably an acidic group such as a carboxyl group, a sulfonic acid group, or a phosphonyl group, or a salt thereof, more preferably It is a carboxyl group or a phosphonyl group or a salt thereof, more preferably a carboxyl group or a salt thereof. When R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ are an acidic group, a salt thereof, or a hydrogen atom, the metal complex dye can be effectively adsorbed on the semiconductor fine particles.

(A3) Ligand LL ²
Ligand LL ² is a bidentate ligand represented by the following general formula (3). M2 representing the number of ligands LL ² ligand LL ² represents 1. The double bond may be E-form or Z-form.

In General formula (3), n1 and n2 represent the integer of 0-3 independently. n1 and n2 are preferably 0 to 3, and more preferably 0 to 1. Y ¹ and Y ² independently represent a hydrogen atom or a heteroaryl group represented by the following general formula (4). Ar ¹ and Ar ² independently represent a heteroaryl group represented by the following general formula (4).
In General Formula (4), R ^{31 to} R ³³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and at least one of R ^{31 to} R ³³ is an alkyl group, an alkoxy group, or an alkynyl group. More preferred are an alkyl group and an alkynyl group, and particularly preferred is an alkynyl group. These may be linear or branched, and preferably have 2 to 15 carbon atoms, more preferably 3 to 12 carbon atoms, and particularly preferably 4 to 8 carbon atoms. By adsorbing the dye in the dye composition to the semiconductor fine particles using the metal complex dye composition having these hydrophobic substituents, the water in the electrolyte in the charge transfer layer is prevented from approaching, Desorption from the semiconductor fine particles can be suppressed. If the number of carbon atoms of the hydrophobic substituent is too large, not only the approach of water but also the approach of, for example, iodine in the electrolyte is hindered, and the reduction from the redox system is not facilitated.
When Y ¹ or Y ² is represented by the general formula (4), it is preferable that Y ¹ or Y ² is conjugated with a pyridine ring, and Ar ¹ and Ar ² are conjugated with a pyridine ring. Along with the electron donating property of Y ¹ or Y ² represented by the general formula (4), these are conjugated, so that the HOMO level to the metal atom M ¹ in the metal complex dye is improved. Light can be absorbed (lengthened). In General Formula (4), X is a sulfur atom, an oxygen atom, a selenium atom, or NR ⁴ , and R ⁴ is a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. X in the general formula (4) is preferably a sulfur atom or a selenium atom, more preferably a sulfur atom, from the viewpoints of stability to nucleophilic species, difficulty in oxidation and difficulty in synthesis. When the ligand LL ² has such a structure, it is possible to suppress the deterioration of the performance of the battery due to the desorption of the dye and to increase the wave length.

It is preferred that the ligand LL ² are represented by the following general formula (7). In General Formula (7), R ^{41 to} R ⁴³ and R ^{51 to} R ⁵³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{41 to} R ⁴³ is an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{51 to} R ⁵³ is an alkyl group, an alkoxy group, or an alkynyl group. X ¹ and X ² are each independently a sulfur atom, an oxygen atom, a selenium atom or NR ⁷ , and R ⁷ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. The double bond may be E-form or Z-form. R ^{41 to} R ⁴³ are preferably an alkyl group or an alkynyl group. R ^{51 to} R ⁵³ are preferably an alkyl group or an alkynyl group. X ¹ and X ² in the general formula (7) are preferably a sulfur atom and a selenium atom, and more preferably a sulfur atom. Since the ligand LL ² has such a structure, n1 and n2 in the general formula (3) are 1, and therefore, there is an effect that the ligand LL2 is less likely to be oxidized and stable as compared with the case of 2 or more. be able to.

It is preferable that the metal complex dye represented by the general formula (1) is represented by the following general formula (8). In General Formula (8), R ⁶¹ and R ⁶² independently represent an alkyl group, an alkoxy group, or an alkynyl group, and A ¹ and A ² independently represent a carboxyl group or a salt thereof. R ⁶¹ and R ⁶² are preferably an alkyl group or an alkynyl group. With this structure, the metal complex dye represented by the general formula (1) can absorb light in a long wavelength region due to the high electron donating property of thiophene. Moreover, desorption of the pigment from the semiconductor fine particles can be suppressed by eliminating the approach of water by the vinylthiophene bonded to the bipyridine ring and the substituent bonded to the thiophene. Further, electrons can be efficiently injected by a carboxyl group or a salt thereof, and light in a long wavelength region can be absorbed by a highly electron donating isothiocyanate group.
In the metal complex dye represented by the general formula (1), by having one each of LL ¹ and LL ² , the dye is adsorbed on the surface of the semiconductor fine particles by the acidic group portion of LL ¹ , and an alkyl group, an alkoxy group or By arranging LL ² having a hydrophobic group such as an alkynyl group on the side opposite to the semiconductor fine particle layer, it is possible to effectively suppress the approach of water and suppress the desorption of the dye.

(A4) Ligand Z ¹
Ligand Z ¹ is at least one selected from isothiocyanato group, an isocyanato group and iso seleno cyanatophenyl group. These groups have high electron donating properties and contribute to the long wave of the dye. The ligand Z ¹ is preferably an isothiocyanato group or an isoselenocyanato group.

(A5) Counter ion CI ¹
CI ¹ in the general formula (1) represents a counter ion when a counter ion is necessary to neutralize the charge. In general, whether a dye is a cation or an anion, or has a net ionic charge, depends on the metal, ligand and substituent in the dye. The number m3 of the counter ion CI ¹ is an integer of 0 or more.

The dye of the general formula (1) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the charge of the whole dye of the general formula (1) is electrically neutralized by the counter ion CI ¹ .

When the counter ion CI ¹ is a positive counter ion, for example, the counter ion CI ¹ is an inorganic or organic ammonium ion (for example, a tetraalkylammonium ion, a pyridinium ion, etc.), an alkali metal ion, or a proton.

When the counter ion CI ¹ is a negative counter ion, for example, the counter ion CI ¹ 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.

(B) Metal Complex Dye of General Formula (5) or General Formula (6) In addition to the metal complex dye represented by the above general formula (1), the metal complex dye composition of the present invention has the following general formula ( A specific amount of at least one of the metal complex dye represented by 5) and the metal complex dye represented by the following general formula (6) is included. The content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is detected at 254 nm of HPLC (high performance liquid chromatography). In area%, it is 0.5 to 5% in the metal complex dye composition.
The metal complex dye of the general formula (5) has one cyano group as a ligand, and the metal complex dye of the general formula (6) has two cyano groups as a ligand. In the general formula (5), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2 and m3 are the same as those in the general formula (1), and in the general formula (6), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m ¹ , m ² , and m 3 have the same meanings as those in the general formula (1), and are not described because they are redundantly described. In general formula (5) and general formula (6), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2 and m3 are the same as in general formula (1). From the viewpoint of
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) (CN) · (CI ¹ ) _{m 3} General formula (5)
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (CN) _2. (CI ¹ ) _{m 3} General formula (6)

The cyano group has a lower electron donating property than the aforementioned isothiocyanato group. Therefore, the metal complex dye represented by the general formula (5) having one cyano group and the metal complex dye represented by the general formula (6) having two cyano groups have a reduced HOMO level and absorption. When the wavelength is shortened and adsorbed on semiconductor fine particles and used as a sensitizing dye, light on the long wave side cannot be effectively used, and conversion efficiency tends to decrease.
However, the content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). By being 0.5 to 5% in the dye composition, the solubility of the dye in the solution can be drastically improved without causing a decrease in conversion efficiency, and the amount of dye adsorbed on the semiconductor fine particles can be increased. And high photoelectric conversion efficiency can be obtained. Moreover, a dye solution can be prepared in a short time, and the productivity of photoelectric conversion element production improves. Although the reason for the improvement of the solubility of the dye in the solution is not clear, a metal complex dye having a cyano group having a chemically different property is used in common with the metal complex dye represented by the general formula (1). The inclusion of 0.5 to 5% seems to be because the crystal arrangement of the metal complex dye is different from that of a high purity of 0.5% or less.
The content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). 5% refers to YMC-Pack ODS-AM312 150 mm × 6.0 mm I.D. D. , Flow rate 0.75 ml / min, oven 40 ° C., eluent composition tetrahydrofuran / water = 63/37 (containing 0.1% trifluoroacetic acid buffer), measurement time 50 minutes.

The metal complex dye represented by the general formula (5) is represented by the following general formula (9), the metal complex dye represented by the general formula (6) is represented by the following general formula (10), and the general formula The total content of the metal complex dye represented by (9) and the metal complex dye represented by the general formula (10) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). It is preferably 5%. In the following general formula (9), R ⁷¹ and R ⁷² independently represent an alkyl group, an alkoxy group or an alkynyl group, and A ⁵ and A ⁶ independently represent a carboxyl group or a salt thereof. In General Formula (10), R ⁷³ and R ⁷⁴ independently represent an alkyl group, an alkoxy group, or an alkynyl group, and A ⁷ and A ⁸ independently represent a carboxyl group or a salt thereof. R ⁷¹ and R ⁷² are preferably an alkyl group or an alkynyl group. R ⁷³ and R ⁷⁴ are preferably an alkyl group or an alkynyl group. The metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) have such a structure, and the total content of these metal complex dyes is HPLC (high speed In the area detected at 254 nm in liquid chromatography), 0.5-5%, the absorption of the dye becomes longer due to the electron donating property of the thiophene ring, and because it has a cyano group, it is significantly converted by shortening the wave. The efficiency can be improved without causing a decrease in efficiency. The total content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is preferably an area detected at 254 nm of HPLC (high performance liquid chromatography). Is 0.5 to 4.5%, more preferably 0.5 to 4%, and particularly preferably 0.5 to 3.5%.

The metal complex dye represented by the general formula (5) is represented by the following general formula (11), and the metal complex dye represented by the general formula (6) is represented by the following general formula (12). preferable. In General Formula (11) and General Formula (12), R ^{81 to} R ⁸⁴ independently represent an alkynyl group, and A ^{13 to} A ¹⁶ independently represent a carboxyl group or a salt thereof. In the metal complex dye having this structure, since R ^{81 to} R ⁸⁴ are alkynyl groups, it is possible to achieve the effect of increasing the wave length of absorption derived from the π-π ^* transition of LL ² due to conjugated elongation and improving ε. Further, since R ^{81 to} R ⁸⁴ are alkynyl groups, the metal complex dye having this structure is improved in the planarity of R ^{81 to} R ⁸⁴ with respect to the thiophene ring or increased on the surface of the semiconductor fine particles due to an increase in π electrons. It is expected that a favorable association that contributes to longer waves may be easily formed between molecules in a state where the dye is adsorbed. R ^{81 to} R ⁸⁴ are preferably a linear or branched alkynyl group having 3 to 13 carbon atoms, more preferably a linear or branched alkynyl group having 3 to 8 carbon atoms, particularly preferably 4 to 7 carbon atoms. Or a linear or branched alkynyl group.

金属錯体色素組成物は、好ましくは有機溶媒中に一般式（１）の金属錯体色素と、一般式（５）で表される金属錯体色素及び／又は一般式（６）で表される金属錯体色素中に溶解させることができる。そのような有機溶媒としては、例えば、アルコール溶媒（メタノール、エタノール、イソプロパノール等）、ニトリル溶媒（アセトニトリル、プロピオニトリル、メトキシプロピオニトリル、バレロニトリル等）、エステル溶媒（酢酸エチル、γ−ブチロラクトン等）、アミド系溶媒（ジメチルホルムアミド、ジメチルアセトアミド、ＮＭＰ）、ハロゲン系溶媒（ジクロロメタン、ジクロロエタン、クロロベンゼン、クロロホルム等）、ベンゼン、トルエン、キシレンなどを挙げることができるが、特に限定されるものではない。また複数の溶媒からなる混合溶媒でもよい。

The metal complex dye composition is preferably a metal complex dye of the general formula (1), a metal complex dye represented by the general formula (5) and / or a metal complex represented by the general formula (6) in an organic solvent. It can be dissolved in the dye. Examples of such organic solvents include alcohol solvents (methanol, ethanol, isopropanol, etc.), nitrile solvents (acetonitrile, propionitrile, methoxypropionitrile, valeronitrile, etc.), ester solvents (ethyl acetate, γ-butyrolactone, etc.) ), Amide solvents (dimethylformamide, dimethylacetamide, NMP), halogen solvents (dichloromethane, dichloroethane, chlorobenzene, chloroform, etc.), benzene, toluene, xylene, and the like, but are not particularly limited. Moreover, the mixed solvent which consists of a some solvent may be sufficient.

(C) Manufacturing method of metal complex dye The metal complex dye of the general formula (1) of the present invention is obtained by externally heating a mixed solution containing a metal complex dye of the following general formula (13) and a compound of the following general formula (14). It can be produced by a method including a step of raising the temperature of the mixed solution.
_{^{M 1 (LL 1) m1 (}} LL 2) m2 (Z 2) m4 · (CI 1) m5 formula (13)
In general formula (13), M ¹ , LL ¹ , LL ² , CI ¹ , m1 and m2 have the same meaning as in general formula (1). Z ² is a monodentate or bidentate ligand. Z ² is preferably a halogen atom (F, Cl, Br, I), water, a dimethylformamide group, —O—C (═O) — (CH ₂ ) _p —C (═O) —O— (p is It represents an integer of 0 or more, preferably 0 to 6, more preferably 0 to 4, particularly preferably 0 to 2.). More preferred are a chlorine atom, water and a dimethylformamide group, and particularly preferred is a chlorine atom. m4 represents an integer of 1 to 2, ^{Z 2} represents m4 is 2 when the monodentate ligands, when ^{Z 2} is a bidentate ligand m4 represents 1. When m4 is 2, Z ² may be the same or different, but is preferably the same. m5 is an integer of 0 or more.

The compound of general formula (14) is represented by the following chemical formula.
M ¹¹ QCN general formula (14)
[In the general formula (14), M ¹¹ is an inorganic or organic ammonium ions, represents a proton or an alkali metal ion, Q is a sulfur atom, an oxygen atom or a selenium atom. ]
M ¹¹ is preferably an inorganic or organic ammonium ion (eg, NH ₄ ⁺ , NBu ₄ ⁺ , NEt ₃ H ⁺ ) or an alkali metal ion (eg, Na ⁺ , K ⁺ , Li ⁺ ), more preferably NH ₄ ^+. , NBu ₄ ⁺ , K ⁺ , particularly preferably NH ₄ ⁺ , K ⁺ . Q is preferably a sulfur atom or a selenium atom, more preferably a sulfur atom, from the viewpoint of the absorption wavelength of the metal complex dye of the general formula (1), that is, the electron donating property of QCN as a ligand.

The metal complex dye represented by the general formula (1) is represented by the following formula as described above.
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) ₂ · (CI ¹ ) _{m 3} General formula (1)
In the general formula (1), M ¹ represents a metal atom, LL ¹ is a bidentate ligand represented by the following general formula (2), and LL ² is represented by the following general formula (3). It is a bidentate ligand. m1 and m2 both represent 1. Z ¹ represents a ligand and is at least one selected from an isothiocyanato group, an isocyanato group and an isoselenocyanato group. Z ¹ may be the same or different, but is preferably the same. CI ¹ represents a counter ion when a counter ion is required to neutralize the charge. m3 is an integer of 0 or more.

［ 一般式（２）中、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は独立して、酸性基若しくはその塩又は水素原子を表し、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４は同じでも異なっていてもよい。ただし、Ｒ^１１〜Ｒ^１４及びＲ^２１〜Ｒ^２４のうち少なくとも一つは酸性基又はその塩である。］

In General formula ^{(2), R} 11 ~R ¹⁴ and ^R 21 ^{to R 24} independently represent an acidic group or a salt thereof, or a hydrogen ^atom, R 11 ^{to R 14} and ^R 21 ^{to R 24} are the same as or different from each other It may be. However, at least one of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ is an acidic group or a salt thereof. ]

［ 一般式（３）中、ｎ１、ｎ２は独立して０〜３の整数を表し、Ｙ^１、Ｙ^２は独立して水素原子又は下記一般式（４）で表されるヘテロアリール基を表す。Ａｒ^１及びＡｒ^２は独立して下記一般式（４）で表されるヘテロアリール基を表す。

[In General Formula (3), n1 and n2 independently represent an integer of 0 to 3, Y ¹ and Y ² independently represent a hydrogen atom or a heteroaryl group represented by the following General Formula (4). . Ar ¹ and Ar ² independently represent a heteroaryl group represented by the following general formula (4).

[In General Formula (4), R ^{31 to} R ³³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and at least one of R ^{31 to} R ³³ represents an alkyl group, an alkoxy group, or an alkynyl group. It is a group. X is a sulfur atom, an oxygen atom, a selenium atom or NR ⁴ , and R ⁴ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ]

The explanations of the general formulas (1) to (4) are the same as those described above, and are omitted because they overlap.
As exemplified in the following synthesis scheme, the metal complex dye of the present invention is obtained by heating a mixed solution containing the metal complex dye of the general formula (13) and the compound of the general formula (14) by external heating. It can be produced by a method including a step of raising the temperature of the mixed solution. As the mixed solution containing the metal complex dye of the general formula (13) and the compound of the general formula (14), an organic solvent can be preferably used. For example, an alcohol solvent (methanol, ethanol, propanol, Isopropanol, butanol, etc.), nitrile solvents (acetonitrile, propionitrile, methoxypropionitrile, valeronitrile, etc.), ester solvents (ethyl acetate, γ-butyrolactone, etc.), amide solvents (dimethylformamide, dimethylacetamide, NMP), Halogen solvents (dichloromethane, dichloroethane, chlorobenzene, chloroform, etc.), benzene, toluene, xylene and the like can be mentioned, but are not particularly limited thereto. Moreover, the mixed solvent which consists of a some solvent may be sufficient, and a mixed solvent with water may be sufficient. The organic solvent is preferably an alcohol solvent, a nitrile solvent, an amide solvent, more preferably an alcohol solvent, an amide solvent, and particularly preferably an amide solvent.

  The method of heating the mixed solution containing the metal complex dye of the general formula (13) and the compound of the general formula (14) to increase the temperature of the mixed solution may be a method of heating from the outside. It is essential. The method of heating from the outside means a method of heating by heat transfer from an external heat source. Although it does not specifically limit as a heat source, The heat source which converts an electrical energy into heat, the heat source by combustion, etc. are mentioned. You may heat said liquid mixture through the medium for the heat obtained from those heat sources. Examples of the medium include oil and water (steam). A method of irradiating microwaves or the like is heating by absorption of microwaves into a substance and conversion of microwave energy into heat, so to speak, heating from the inside, not including external heating. In internal heating with microwave irradiation or the like, the heating principle is different from external heating, and the metal complex is directly heated and the heating energy is too large. Since decomposition of the compound 14) or the metal complex dye of the general formula (1) occurs, it is not preferable for producing the metal complex dye of the present invention. As a method by external heating, a method of heating the mixed solution with an oil bath or steam can be preferably mentioned. The heating temperature and the reaction time can be appropriately selected depending on the metal complex dye to be reacted and the solvent used. The heating temperature is preferably 90 to 170 ° C, more preferably 90 to 160 ° C, particularly preferably 100 to 150 ° C, and most preferably 100 to 140 ° C. The reaction time is preferably 30 minutes to 12 hours, more preferably 1 to 8 hours, and further preferably 2 to 6 hours.

As shown in the following scheme, the metal complex dye of the general formula (13) can be obtained by introducing LL ¹ and LL ² into a compound having Ru. Although it does not specifically limit as a Ru source, For example, ruthenium chloride, its hydrate, d-1-6 mentioned later, etc. are mentioned. Preferably, it is d-1-6 described later in which the valence of Ru is divalent. The order of introduction of LL ¹ and LL ² is not particularly limited, but introduction from LL ² is preferred. Z ² is usually determined by the Ru source, but additives (potassium iodide, potassium oxalate, KO—C (═O) — (CH ₂ ) _p —C (═O) —OK (p is an integer of 0 or more) Z ² can be changed by using the like)). Also it is a Z ² by coordinating solvent. Thereafter, the compound (14) is placed in the obtained solution containing the metal complex dye of the general formula (13), and heated from the outside as described above to obtain the metal complex dye of the general formula (1).

In the general formula (13), the ligand LL ² is preferably represented by the following general formula (7). In the following general formula (7), R ^{41 to} R ⁴³ and R ^{51 to} R ⁵³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{41 to} R ⁴³ is an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{51 to} R ⁵³ is an alkyl group, an alkoxy group, or an alkynyl group. X ¹ and X ² are a sulfur atom, an oxygen atom, a selenium atom or NR ⁷ , and R ⁷ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. R ^{41 to} R ⁴³ are preferably an alkyl group or an alkynyl group. R ^{51 to} R ⁵³ are preferably an alkyl group or an alkynyl group. X ¹ and X ² in the general formula (7) are preferably a sulfur atom and a selenium atom, and more preferably a sulfur atom.

The metal complex dye of the general formula (13) is represented by the following general formula (15), and the compound of the general formula (14) is represented by the following general formula (16). A method for producing the metal complex dye represented is preferred. In General Formula (8) and General Formula (15), R ⁶¹ , R ⁶² , R ⁹¹ , R ⁹² independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and A ^{1 to} A ⁴ are independently Represents a carboxyl group or a salt thereof. In General Formula (16), M ¹² represents an inorganic or organic ammonium ion, proton, or alkali metal ion. R ⁶¹ , R ⁶² , R ⁹¹ and R ⁹² are preferably an alkyl group or an alkynyl group. Since the metal complex dye (13) and the compound of the general formula (14) have these structures, the metal complex dye (13) has a stable thiophene ring with respect to the nucleophilic compound (14). Therefore, an undesired nucleophilic reaction can be suppressed, and Cl having a high detachment ability and a low nucleophilic ability becomes a leaving group, whereby the metal of the general formula (8) in which the —NCS group is selectively coordinated to the Ru atom. Complex dyes can be produced efficiently.

The metal complex dye of the general formula (13) is represented by the following general formula (18), and the compound of the general formula (14) is represented by the following general formula (19). A method for producing the metal complex dye represented is preferred. In General Formula (17) and General Formula (18), R ¹⁰¹ , R ¹⁰² , R ¹¹¹ and R ¹¹² independently represent an alkynyl group, and A ^{9 to} A ¹² independently represent a carboxyl group or a salt thereof. In the general formula (19), M ¹³ represents an inorganic or organic ammonium ion, proton, or alkali metal ion. R ¹⁰¹ , R ¹⁰² , R ¹¹¹ and R ¹¹² are preferably a linear or branched alkynyl group having 3 to 13 carbon atoms, more preferably a linear or branched alkynyl group having 3 to 8 carbon atoms, particularly preferably A linear or branched alkynyl group having 4 to 7 carbon atoms.

  The dye represented by the general formula (1) has a maximum absorption wavelength in the solution in the range of 500 to 700 nm, and more preferably in the range of 500 to 650 nm.

  Specific examples of the dye having the structure represented by the general formula (1) 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 form a salt with a counter ion. In addition, there are isomers based on the double bond site, isomers based on the position of the ligand of the complex, and the like, either of which may be a mixture.

(D) Charge transfer body In the electrolyte composition used for the photoelectric conversion element 10 of the present invention, as an oxidation-reduction pair, for example, iodine and iodide (for example, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.) ), Combinations of alkyl viologens (eg methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and their reduced forms, combinations of polyhydroxybenzenes (eg hydroquinone, naphthohydroquinone, etc.) and their oxidants Examples thereof include combinations of divalent and trivalent iron complexes (for example, red blood salt and yellow blood salt). Of these, a combination of iodine and iodide is preferred.

  The cation of the iodine salt is preferably a 5-membered or 6-membered nitrogen-containing aromatic cation. In particular, when the compound represented by the general formula (1) is not an iodine salt, republished WO95 / 18456, JP-A-8-259543, Electrochemistry, Vol.65, No.11, p.923 (1997) It is preferable to use iodine salts such as pyridinium salts, imidazolium salts, and triazolium salts described in the above.

  The electrolyte composition used for the photoelectric conversion element 10 of the present invention preferably contains iodine together with the heterocyclic quaternary salt compound. The iodine content is preferably 0.1 to 20% by mass, and more preferably 0.5 to 5% by mass with respect to the entire electrolyte composition.

  The electrolyte composition used for the photoelectric conversion element 10 of the present invention may contain a solvent. The content of the solvent in the electrolyte composition is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less based on the entire composition.

  As the solvent, those having a low viscosity and high ion mobility, a high dielectric constant and capable of increasing the effective carrier concentration, or both are preferable because they can exhibit excellent ion conductivity. As such a solvent, carbonate compounds (ethylene carbonate, propylene carbonate, etc.), heterocyclic compounds (3-methyl-2-oxazolidinone, etc.), ether compounds (dioxane, diethyl ether, etc.), chain ethers (ethylene glycol dialkyl ether, Propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.), Polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol Nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, biscyanoethyl ether, etc.), esters (carboxylic esters, phosphate esters, phosphonates, etc.) ), Aprotic polar solvent (dimethyl sulfoxide (DMSO), sulfolane, etc.), water, hydrous electrolyte described in JP-A No. 2002-110262, JP-A No. 2000-36332, JP-A No. 2000-243134, and republication Examples include electrolyte solvents described in WO / 00-54361. These solvents may be used as a mixture of two or more.

Further, as an electrolyte solvent, which is liquid state at room temperature, and may be used electrochemically inactive salt having a melting point lower than room temperature. For example, 1-ethyl - 3-methylimidazolium trifluoromethanesulfonate, 1-butyl - 3-methylimidazolium trifluoromethanesulfonate, etc., nitrogen-containing heterocyclic quaternary salt compounds such as imidazolium salt and pyridinium salt, or tetraalkylammonium Examples include salt.

  The electrolyte composition used in the photoelectric conversion element of the present invention may be added with a polymer or an oil gelling agent, or may be gelled (solidified) by a technique such as polymerization of polyfunctional monomers or polymer crosslinking reaction. .

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

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

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

  The gel electrolyte may be formed by polymerization of a mixture containing a monofunctional monomer in addition to the above polyfunctional monomers. Monofunctional monomers include acrylic acid or α-alkyl acrylic acid (acrylic acid, methacrylic acid, itaconic acid, etc.) or their esters or amides or vinyl esters (vinyl acetate, etc.), maleic acid or fumaric acid or their derivatives. Esters (dimethyl maleate, dibutyl maleate, diethyl fumarate, etc.), sodium salt of p-styrenesulfonic acid, acrylonitrile, methacrylonitrile, dienes (butadiene, cyclopentadiene, isoprene, etc.), aromatic vinyl compounds (Styrene, p-chlorostyrene, t-butylstyrene, α-methylstyrene, sodium styrenesulfonate, etc.), N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N- Methylacetamide, Vinyl sulfonic acid, sodium vinyl sulfonate, sodium allyl sulfonate, sodium methacryl sulfonate, vinylidene fluoride, vinylidene chloride, vinyl alkyl ethers (such as methyl vinyl ether), ethylene, propylene, butene, isobutene, N-phenylmaleimide, etc. It can be used.

  The blending amount of the polyfunctional monomer is preferably 0.5 to 70% by mass and more preferably 1.0 to 50% by mass with respect to the whole monomer. The above-mentioned monomers are the same as those described in Takayuki Otsu and Masaaki Kinoshita “Experimental Methods for Polymer Synthesis” (Chemistry Dojin) and Takayuki Otsu “Lecture Polymerization Reaction Theory 1 Radical Polymerization (I)” (Chemical Doujinshi). Polymerization can be performed by radical polymerization which is a polymer synthesis method. The monomer for gel electrolyte used in the present invention can be radically polymerized by heating, light or electron beam, or electrochemically, and is particularly preferably radically polymerized by heating. In this case, preferably used polymerization initiators are 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropyl). Pionate), azo initiators such as dimethyl 2,2′-azobisisobutyrate, peroxide initiators such as lauryl peroxide, benzoyl peroxide, and t-butyl peroctoate. The preferable addition amount of a polymerization initiator is 0.01-20 mass% with respect to the monomer total amount, More preferably, it is 0.1-10 mass%.

The weight composition range of the monomer in the gel electrolyte is preferably 0.5 to 70% by mass. More preferably, it is 1.0-50 mass%. When the electrolyte composition is gelled by a polymer crosslinking reaction, it is preferable to add a polymer having a reactive group capable of crosslinking to the composition and a crosslinking agent. Preferred reactive groups are nitrogen-containing heterocycles such as pyridine ring, imidazole ring, thiazole ring, oxazole ring, triazole ring, morpholine ring, piperidine ring, piperazine ring, and the preferred crosslinking agent is a functional group capable of nucleophilic attack by the nitrogen atom. Is a compound (electrophile) having two or more of, for example, a bifunctional or higher functional alkyl halide, halogenated aralkyl, sulfonic acid ester, acid anhydride, acid chloride, isocyanate and the like.

The electrolyte composition of the present invention, metal iodides (LiI, NaI, KI, CsI , CaI 2 , etc.), a metal bromide (LiBr, NaBr, KBr, CsBr , CaBr 2 , etc.), quaternary ammonium bromine salt (tetraalkylammonium Ammonium bromide, pyridinium bromide, etc.), metal complexes (ferrocyanate-ferricyanate, ferrocene-ferricinium ion, etc.), sulfur compounds (sodium polysulfide, alkylthiol-alkyldisulfides, etc.), viologen dye, hydroquinone-quinone Etc. may be added. These may be used as a mixture.

  Further, in the present invention, J.P. Am. Ceram. Soc. 80, (12), 3157-3171 (1997), and basic compounds such as 2-picoline and 2,6-lutidine may be added. A preferable concentration range in the case of adding a basic compound is 0.05 to 2M.

  Further, as the electrolyte of the present invention, a charge transport layer containing a hole conductor material may be used. As the hole conductor material, a 9,9'-spirobifluorene derivative or the like can be used.

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

The conductive layer is not particularly limited as long as it has good conductivity, and examples thereof include inorganic conductive materials, organic conductive materials, conductive polymers, and intermolecular charge transfer complexes. Among them, an intermolecular charge transfer complex formed from a donor material and an acceptor material is preferable. Among these, what was formed from the organic donor and the organic acceptor can be used preferably.
The thickness of this conductive layer is not particularly limited, but is preferably such that the porous layer can be completely filled.

  The donor material is preferably a material rich in electrons in the molecular structure. For example, organic donor materials include those having an amine group, hydroxyl group, ether group, selenium or sulfur atom in the π-electron system of the molecule, specifically, phenylamine-based, triphenylmethane-based, carbazole-based , Phenol-based materials, and tetrathiafulvalene-based materials. As the acceptor material, those lacking electrons in the molecular structure are preferable. For example, organic acceptor materials include fullerenes, those having a substituent such as a nitro group, a cyano group, a carboxyl group or a halogen group in the π-electron system of the molecule, specifically, PCBM, benzoquinone, naphthoquinone, etc. Quinone, fluoroenone, chloranil, bromanyl, tetracyanoquinodimethane, tetracyanoethylene and the like.

(E) Conductive Support As shown in FIG. 1, in the photoelectric conversion element of the present invention, a photosensitive layer 2 in which a sensitizing dye 21 is adsorbed on porous semiconductor fine particles 22 on a conductive support 1. Is formed. As will be described later, for example, the photoreceptor layer 2 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 1, glass or a polymer material having a conductive film on the surface can be used as the support itself, such as metal. The conductive support 1 is preferably 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 1, a glass or polymer material coated with a conductive metal oxide can be used. The coating amount of the conductive metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of the support of glass or polymer material. When a transparent conductive support is used, light is preferably incident from the support side. Examples of polymer materials that are preferably used include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), Examples include polyarylate (PAR), polysulfone (PSF), polyester sulfone (PES), polyetherimide (PEI), cyclic polyolefin, and brominated phenoxy. On the conductive support 1, the surface may be provided with a light management function. For example, an antireflection film in which high refractive films and low refractive index oxide films described in JP-A-2003-123859 are alternately laminated, The light guide function described in JP-A-2002-260746 is improved.

  In addition to this, a metal support can also be preferably used. Examples thereof include titanium, aluminum, copper, nickel, iron, stainless steel, and copper. These metals may be alloys. More preferably, titanium, aluminum, and copper are preferable, and titanium and aluminum are particularly preferable.

  It is preferable that the conductive support 1 has a function of blocking ultraviolet light. For example, a method in which a fluorescent material capable of changing ultraviolet light into visible light is present in the transparent support or on the surface of the transparent support, or a method using an ultraviolet absorber is also included.

  On the conductive support 1, a function described in JP-A-11-250944 may be further provided.

  Preferred conductive films include metals (eg, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.) ).

  The thickness of the conductive film is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm.

The conductive support 1 preferably has a lower surface resistance. The range of the surface resistance is preferably 50 Ω / cm ² or less, more preferably 10 Ω / cm ² or less. This lower limit is not particularly limited, but is usually about 0.1 Ω / cm ² .

  Since the resistance value of the conductive film increases as the cell area increases, a collecting electrode may be disposed. One or both of a gas barrier film and an ion diffusion preventing film may be disposed between the conductive support 1 and the transparent conductive film. As the gas barrier layer, a resin film or an inorganic film can be used.

  Moreover, you may provide a transparent electrode and a porous semiconductor electrode photocatalyst content layer. The transparent conductive film may have a laminated structure, and as a preferable method, for example, FTO can be laminated on ITO.

(F) Semiconductor Fine Particle As shown in FIG. 1, the photoelectric conversion element 10 of the present invention has a photosensitive layer 2 in which a sensitizing dye 21 is adsorbed on a porous semiconductor fine particle 22 on a conductive support 1. Is formed. As will be described later, for example, the photoreceptor layer 2 can be produced by immersing the dispersion of the semiconductor fine particles 22 on the conductive support 1 and then immersing it in the above dye solution.

  As the semiconductor fine particles 22, 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 n-type semiconductors, in addition to intrinsic semiconductors (for example, intrinsic semiconductors) having no impurity level and equal carrier concentration due to conduction band electrons and valence band holes, the electron carrier concentration is reduced by structural defects derived from impurities. There are high n-type semiconductors. The n-type inorganic semiconductor preferably used in the present invention is TiO ₂ , TiSrO ₃ , ZnO, Nb ₂ O ₃ , SnO ₂ , WO ₃ , Si, CdS, CdSe, V ₂ O ₅ , ZnS, ZnSe, SnSe, KTaO. ₃ , FeS ₂ , PbS, InP, GaAs, CuInS ₂ , CuInSe ₂ and the like. Of these, the most preferred n-type semiconductors are TiO ₂ , ZnO, SnO ₂ , WO ₃ , and Nb ₂ O ₃ . A semiconductor material in which a plurality of these semiconductors are combined is also preferably used.

  The method for producing the semiconductor fine particles 22 is preferably the gel-sol method described in Sakuo Sakuo's “Science of Sol-Gel Method”, Agne Jofu Co., Ltd. (1998). 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 22 are titanium oxide, the sol-gel method, the gel-sol method, and the high-temperature hydrolysis method in oxyhydrogen salt of chloride are all preferable. It is also possible to use the sulfuric acid method and the chlorine method described in Gihodo Publishing (1997). 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 Hydrolysis of the soluble part, formation of fine semiconductor particles from soluble and insoluble parts, dissolution and removal of soluble part, hydrothermal synthesis of peroxide aqueous solution, or production of core / shell structured titanium oxide fine particles by sol-gel method A method is mentioned.

  Examples of the crystal structure of titania include anatase type, brookite type, and rutile type, and anatase type and brookite type are preferable.

  Titania nanotubes, nanowires, and nanorods may be mixed with titania fine particles.

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

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

(G) Semiconductor fine particle dispersion In the present invention, a semiconductor fine particle dispersion having a solid content other than semiconductor fine particles of 10% by mass or less of the whole semiconductor fine particle dispersion is applied to the conductive support 1, A porous semiconductor fine particle coating layer can be obtained by heating to a high temperature.

  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, one or more of water and various organic solvents can be used. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, citronellol and terpineol, ketones such as acetone, esters such as ethyl acetate, dichloromethane, acetonitrile and the like.

  At the time of dispersion, a small amount of, for example, a polymer such as polyethylene glycol, hydroxyethyl cellulose, carboxymethyl cellulose, a surfactant, an acid, or a chelating agent may be used as a dispersion aid. However, most of these dispersing aids are preferably removed by a filtration method, a method using a separation membrane, a centrifugal method or the like before the step of forming a film on a conductive support. In the semiconductor fine particle dispersion, the solid content other than the semiconductor fine particles can be 10% by mass or less of the total dispersion. This concentration is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. More preferably, it is 0.5% or less, and particularly preferably 0.2%. That is, in the semiconductor fine particle dispersion, the solid content other than the solvent and the semiconductor fine particles can be 10% by mass or less of the entire semiconductor fine dispersion. It is preferable to consist essentially of semiconductor fine particles and a dispersion solvent.

If the viscosity of the semiconductor fine particle dispersion is too high, the dispersion 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. Further, the application system method and the metering system method can be made the same part. The wire bar method disclosed in Japanese Patent Publication No. 58-4589, the slide hopper method described in US Pat. No. 2,681,294, etc., the extrusion 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 1 is increased, and it becomes easy to apply the semiconductor fine particle dispersion. .

The preferred thickness of the entire semiconductor fine particle layer is 0.1 μm to 100 μm. The thickness of the semiconductor fine particle layer is further preferably 1 μm to 30 μm, and more preferably 2 μm 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 g 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 22, the surface may be activated by applying light absorbed by the semiconductor fine particles 22 such as ultraviolet light, or only the surface of the semiconductor fine particles 22 is activated by laser light or the like. Can be By irradiating the semiconductor fine particles 22 with light absorbed by the fine particles, the impurities adsorbed on the particle surfaces are decomposed by the activation of the particle surfaces, and can be brought into a preferable state for the above purpose. When the heat treatment and ultraviolet light are combined, the heating is preferably 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 22 with light absorbed by the fine particles. . Thus, by photoexciting the semiconductor fine particles 22, 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 1, 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.

  As the method for coating the semiconductor fine particles 22 on the conductive support 1, the semiconductor fine particles 22 described in Japanese Patent No. 2664194 can be used in addition to the method of applying the semiconductor fine particle dispersion on the conductive support 1. It is possible to use a method such as a method in which the precursor is applied on the conductive support 1 and hydrolyzed with moisture in the air to obtain a semiconductor fine particle film.

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 pH of the slurry 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.

  Examples of the technology relating to the formation of the semiconductor fine particles 22 or the precursor layer thereof include a method of hydrophilizing by a physical method such as corona discharge, plasma, and UV, a chemical treatment with alkali, polyethylenedioxythiophene and polystyrenesulfonic acid, polyaniline, etc. Forming an intermediate film for bonding.

  As a method of coating the semiconductor fine particles 22 on the conductive support 1, (2) 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 for 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 22 preferably have a large surface area so that many sensitizing dyes 21 can be adsorbed. For example, in a state where the semiconductor fine particles 22 are coated on the conductive support 1, the surface area thereof 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. As a preferable structure of the semiconductor fine particles 22, JP 2001-93591 A and the like can be mentioned.

  In general, as the thickness of the semiconductor fine particle layer increases, the amount of the sensitizing dye 21 that can be carried per unit area increases, so that the light absorption efficiency increases. However, the loss due to charge recombination increases because the diffusion distance of the generated electrons increases. Become. The preferred thickness of the semiconductor fine particle layer varies depending on the use of the device, but is typically 0.1 μm to 100 μm. When used as a photoelectrochemical cell, the thickness is preferably 1 μm to 50 μm, more preferably 3 μm to 30 μm. The semiconductor fine particles may be heated at a temperature of 100 ° C. to 800 ° C. for 10 minutes to 10 hours in order to bring the particles into close contact after being applied to the support. When glass is used as the support, the film forming temperature is preferably 400 ° C to 600 ° C.

  When a polymer material is used as the support, it is preferable to heat 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 22 per 1 m ² of the support is preferably 0.5 g to 500 g, more preferably 5 g to 100 g.

In order to adsorb the sensitizing dye 21 to the semiconductor fine particles 22, it is preferable to immerse the well-dried semiconductor fine particles 22 in a dye adsorbing dye solution comprising the solution and the dye according to the present invention for a long time. The solvent used for the dye solution for dye adsorption can be used without particular limitation as long as it can dissolve the sensitizing dye 21 according to the present invention. Such a solvent that dissolves the metal complex dye composition in the present invention is an organic solvent, and examples thereof include nonpolar solvents, polar aprotic solvents, polar protic solvents, ionic liquids, and the like, preferably nonpolar Solvents, polar aprotic solvents, polar protic solvents are mentioned as preferred targets, for example, ethanol, methanol, isopropanol, toluene, t-butanol, acetonitrile, acetone, n-butanol, N, N-dimethylformamide, N, N-dimethylacetamide and the like can be used. Among these, ethanol and toluene can be preferably used.
In the present invention, the solubility of the metal complex dye composition in the above solvent is 25 ° C., preferably 100 mg / L or more, more preferably 105 mg / L or more, and particularly preferably 110 mg / L or more.

  A dye solution for dye adsorption comprising a solvent and the dye of the present invention may be heated to 50 ° C. to 100 ° C. as necessary. Adsorption of the sensitizing dye 21 may be performed before or after the application of the semiconductor fine particles 22. Alternatively, the semiconductor fine particles 22 and the sensitizing dye 21 may be applied and adsorbed simultaneously. Unadsorbed sensitizing dye 21 is removed by washing. When baking a coating film, it is preferable to adsorb | suck the sensitizing dye 21 after baking. It is particularly preferable that the sensitizing dye 21 is quickly adsorbed after baking and before water is adsorbed on the coating film surface. The sensitizing dye 21 to be adsorbed may be one kind of the dye A1 described above, or may be mixed with another dye. The dye to be mixed is selected so as to make the wavelength range of photoelectric conversion as wide as possible. When mixing the dyes, it is preferable to prepare a dye solution for dye adsorption by dissolving all the dyes.

The total amount of the sensitizing dye 21 used is preferably from 0.01 mmol to 100 mmol, more preferably from 0.1 mmol to 50 mmol, and particularly preferably from 0.1 mmol to 10 mmol, per 1 m ² of the support. . In this case, the amount of the sensitizing dye 21 according to the present invention is preferably 5 mol% or more.

  Further, the adsorption amount of the sensitizing dye 21 to the semiconductor fine particles 22 is preferably 0.001 mmol 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 sensitizing dye 21, the surface of the semiconductor fine particles 22 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 4 functions as a positive electrode of the photoelectrochemical cell. The counter electrode 4 is usually synonymous with the conductive support 1 described above, but a support for the counter electrode 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 4 include platinum, carbon, and conductive polymer. Preferable examples include platinum, carbon, and conductive polymer.

  The structure of the counter electrode 4 is preferably a structure having a high current collecting effect. 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 5, 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 photoelectric conversion element may have a structure in which a first electrode layer, a first photoelectric conversion layer, a conductive layer, a second photoelectric conversion layer, and a second electrode layer are sequentially stacked. In this case, the dyes used for the first photoelectric conversion layer and the second photoelectric conversion layer may be the same or different, and in the case of being different, the absorption spectra are preferably different.

  The light receiving electrode 5 may be a tandem type in order to increase the utilization rate of incident light. Preferred examples of the tandem type configuration include those described in JP-A Nos. 2000-90989 and 2002-90989.

  A light management function for efficiently performing light scattering and reflection inside the layer of the light receiving electrode 5 may be provided. Preferably, the thing of Unexamined-Japanese-Patent No. 2002-93476 is mentioned.

  It is preferable to form a short-circuit prevention layer between the conductive support 1 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 5 and the counter electrode 4, it is preferable to use a spacer or a separator. A preferable example is JP-A No. 2001-283941.

  Cell and module sealing methods include polyisobutylene thermosetting resin, novolak resin, photo-curing (meth) acrylate resin, epoxy resin, ionomer resin, glass frit, method using aluminum alkoxide for alumina, low melting point glass paste It is preferable to use a laser melting method. When glass frit is used, powder glass mixed with acrylic resin as a binder may be used.

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

1. 1. Preparation of crude product of metal complex dye A crude product of metal complex is prepared by the following (1) method by external heating and (2) by microwave heating. Purified.
(1) Preparation of crude purified product of metal complex dye by external heating (a) Preparation of crude purified product of metal complex dye D-20 Among the metal complex dyes of the general formula (1) shown in the specific examples, D- Twenty crude products were prepared by the method shown below.

<Ligand synthesis>
(I) Preparation of compound d-1-2 25 g of d-1-1, 3.8 g of Pd ₂ (dba) ₃ , 8.6 g of triphenylphosphine, 2.5 g of copper iodide, 1-heptin 25. 2 g was stirred in 70 mL of triethylamine and 50 mL of tetrahydrofuran at room temperature, and stirred at 80 ° C. for 4.5 hours. After concentration, the residue was purified by column chromatography to obtain 26.4 g of d-1-2.

(Ii) Preparation of d-1-4 6.7 g of d-1-3 was dissolved in 200 mL of THF (terahydrofuran) at −15 ° C. under a nitrogen atmosphere, and LDA (lithium diisopropylamide) separately prepared was 2.5 equivalents was dripped with respect to d-1-3, and it stirred for 75 minutes. Thereafter, a solution of 15 g of d-1-2 dissolved in 30 mL of THF was added dropwise, stirred at 0 ° C. for 1 hour, and stirred overnight at room temperature. 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.

<Complexation>
Complexation was performed by external heating to prepare a metal complex dye D-20. 3.0 g of d-1-5 and 1.64 g of d-1-6 synthesized above were added to 35 mL of DMF, and the mixture was stirred at 70 ° C. for 90 minutes in the dark. In that case, it heated with the oil bath from the outside. Thereafter, 1.3 g of d-1-7 was added, 270 mL of DMF was added, and the mixture was heated and stirred at 160 ° C. for 150 minutes. In that case, it heated with the oil bath from the outside. Then, 14.25 g of ammonium thiocyanate was added and stirred at 130 ° C. for 5 hours. In that case, it heated with the oil bath from the outside. After concentration, 300 mL of water was added and filtered, and washed with diethyl ether to obtain a crude product of D-20.

(B) Preparation of Crude Purified Product of Metal Complex Dye D-10 Among the metal complex dyes of the general formula (1) shown in the specific examples, a crude purified product of D-10 was prepared by the method shown below.

<Ligand synthesis>
Compound d-2-5 was prepared by the following method.
(I) Preparation of Compound d-2-2 25 g of d-2-1 was dissolved in 500 mL of tetrahydrofuran and cooled with ice, and 1.05 equivalent of n-butyllithium (1.6 mol / L hexane solution) was added dropwise. did. Thereafter, 1.5 equivalent of dimethylformamide was added dropwise and stirred at room temperature for 1 hour. A saturated aqueous ammonium chloride solution was added dropwise, followed by liquid separation / extraction, concentration, and purification by distillation under reduced pressure to obtain 25.6 g of compound d-2-2.

(Ii) Preparation of d-2-4 In preparing the metal complex dye D-20 of (a), d-1-2 used for the preparation of d-1-4 was changed to d-2-2. Similarly, d-2-4 was prepared using d-2-3.

(Iii) Preparation of compound d-2-5 In preparing the metal complex dye D-20 of (a), d-1-4 used for the preparation of d-1-5 was changed to d-2-4. Except that, d-2-5 was prepared in the same manner.

<Complexation>
Complexation was carried out by external heating to prepare a crude product of metal complex dye D-10.
A crude product of D-10 was prepared in the same manner except that d-1-5 used when preparing D-20 in (a) was changed to d-2-5.

(2) Preparation of crude product of metal complex dye by microwave heating (a) Preparation of crude product of metal complex dye D-20 3.0 g of compound d-1-5 and 1.64 g of d-1- 6 was added to 35 mL of DMF and irradiated with microwaves (frequency: 2.45 GHz) in the dark and stirred at 70 ° C. for 10 minutes. Thereafter, 1.3 g of d-1-7 was added, 270 mL of DMF was added, and the mixture was heated and stirred at 160 ° C. for 10 minutes using the microwave. Then, 14.25 g of ammonium thiocyanate was added and stirred at 130 ° C. for 10 minutes using the above microwave. After concentration, 300 mL of water was added and filtered, and washed with diethyl ether to obtain a crude product D-20.

(B) Preparation of roughly purified product of metal complex dye D-10 (1) Except that external heating in (b) was changed to microwave heating (same conditions as in (2) (a)), 2 .5 g of a crude product of D-10 was obtained.

2. Preparation of metal complex dye composition containing metal complex dye of general formula (5) and / or metal complex dye of general formula (6) and metal complex dye (1) Preparation of metal complex dye composition by external heating (1) The crudely purified product of the metal complex dye D-20 obtained in (a) is dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide), and separated on a Sephadex LH-20 (trade name, manufactured by GE Healthcare) column. Purified. The main layer fraction was collected and concentrated, and then 0.2 M nitric acid was added to obtain a precipitate. A metal complex dye composition comprising at least one of a metal complex dye of general formula (5) and a metal complex dye of general formula (6) mainly containing D-17 by washing with water and diethyl ether after filtration Got. At the time of column purification, 50 g of the carrier is used for 200 mg of the crude product, and the number of column purification is changed from 1 to 4 times, whereby the metal complex dye of the general formula (5) and the general formula (6) Metal complex dye compositions (Examples 1 to 4) containing at least one of the metal complex dyes were obtained.
In the same manner, the crude purified product of the metal complex dye D-10 obtained in (1) (b) is purified, and the metal complex dye of the general formula (5) containing D-11 as the main component and the general formula ( Metal complex dye compositions (Examples 5 to 8) containing at least one of the metal complex dyes of 6) were obtained. Further, the obtained metal complex dye composition is further dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide), and a 0.1N methanol solution of methanol is added dropwise to pH 0, so that D-10 is a main component. Metal complex dye compositions (Examples 9 to 12) containing at least one of the metal complex dye of the formula (5) and the metal complex dye of the general formula (6) were obtained.

(2) Preparation of metal complex dye composition by microwave heating For comparison with (1), (2) The crude product of the metal complex dye D-20 prepared by microwave heating obtained in (a) is purified by the same method as in (1), and the general formula comprising D-17 as the main component Metal complex dye compositions containing at least one of the metal complex dye of (5) and the metal complex dye of the general formula (6) were obtained (Comparative Examples 1 to 3). In the same manner, 1. (2) The crudely purified product of the metal complex dye D-10 obtained in (b) is purified, and the metal complex dye of the general formula (5) and the metal complex of the general formula (6) containing D-11 as a main component Metal complex dye compositions containing at least one of the dyes were obtained (Comparative Examples 5 to 7). Further, the obtained metal complex dye composition is further dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide), and a 0.1N methanol solution of methanol is added dropwise to pH 0, so that D-10 is a main component. Metal complex dye compositions (Comparative Examples 9 to 11) containing at least one of the metal complex dye of the formula (5) and the metal complex dye of the general formula (6) were obtained.

(3) Preparation of metal complex dye by HPLC fractionation (1) The crude product obtained in (a) was purified by HPLC (high performance liquid chromatography). At that time, the crude product was dissolved in a methanol solution of TBAOH (tetrabutylammonium hydroxide), and the composition of the eluent was methanol / water = using a CAPCELL PAK UG120 φ30 mm × 250 mm LC preparative column manufactured by Shiseido. Purified as 85/15 to 95/5. The main layer fraction was collected and concentrated, and then 0.2 M nitric acid was added to obtain a precipitate. After filtration, it was washed with water and diethyl ether to obtain 3.2 g of a metal complex dye D-17 represented by the general formula (1) (Comparative Example 4).
The structure of the obtained metal complex dye D-17 was confirmed by NMR measurement and LC-MS.
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)
MS-ESI m / z: 1023.143 (M + H) ⁺

The obtained metal complex dye D-17 (Comparative Example 8) was dissolved in tetrahydrofuran: water = 63: 37 (0.1% trifluoroacetic acid) to prepare a solution having a concentration of 8.5 μmol / L, and U-4100 spectrophotometer When the spectral absorption measurement was performed using (trade name, manufactured by Hitachi), the absorption maximum wavelength was 568 nm.
Similarly, the metal complex dye D-11 (Comparative Example 8) is 1. (1) Obtained by purification by HPLC using the crude product obtained in (b).
MS-ESI m / z: 1003.2 (M + H) ⁺
Then, it is dissolved in tetrahydrofuran: water = 63: 37 (0.1% trifluoroacetic acid) to prepare a solution having a concentration of 8.5 μmol / L, and spectral absorption measurement is performed using U-4100 spectrophotometer (manufactured by Hitachi). As a result, the absorption maximum wavelength was 566 nm.

The obtained metal complex dye D-11 was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide), and 0.1N nitric acid methanol solution was dropped to pH 0 to obtain D-10 (Comparative Example 12). .
MS-ESI m / z: 1003.2 (M + H) ⁺
Then, it is dissolved in tetrahydrofuran: water = 63: 37 (0.1% trifluoroacetic acid) to prepare a solution having a concentration of 8.5 μmol / L, and spectral absorption measurement is performed using U-4100 spectrophotometer (manufactured by Hitachi). As a result, the absorption maximum wavelength was 571 nm.

3. 1. Measurement of the content of the metal complex dye of the general formula (5) and / or the metal complex dye of the general formula (6) in the metal complex composition. The metal complex dye contained in the metal complex dye composition obtained in (1) was identified and its content was determined by the following (a) to (b). The values are shown in Table 1.
(A) Measurement by high performance liquid chromatography The metal complex dye composition obtained in 1 above was measured by high performance liquid chromatography under the following conditions. The content of the metal complex dye of the general formula (5) and / or the metal complex dye of the general formula (6) was determined by identifying the metal complex having a CN ligand together with the measurement results of LC-MS described later.
(Measurement conditions of high performance liquid chromatography (HPLC))
Equipment used: System controller SCL-10AVP
Column oven CTO-10ASVP
Detector SPD-10AVVP
Degasser DGU-14AM
Liquid feeding unit LC-10ADVP
(Product name: Shimadzu)
Column: YMC-Pack ODS-AM, model number AM-312
Size 150 × 6.0 mm I.D. D. (Manufactured by YMC Co., Ltd. Japan)
Flow rate: 0.75 mL / min
Eluent: THF / water = 63/37 containing 0.1% trifluoroacetic acid Temperature: 40 ° C.
Detection wavelength: 254 nm

(B) Identification of metal complex dye in metal complex dye composition The structure of the metal complex dye contained in the metal complex dye composition was identified by measuring LC-MS of the metal complex dye composition. LC-MS was performed by the following method.
(Measurement conditions for LC-MS)
Apparatus: Applied Biosystems QSTAR pulser (trade name), Applied Biosystems ionization method: ESI-posi
Detection method: TOF-MS
Column: YMC-Pack ODS-AM, model number AM-312
Size 150 × 6.0 mm I.D. D. (Manufactured by YMC Co., Ltd. Japan)
Flow rate: 0.75 mL / min
Eluent: THF / water = 63/37 Temperature containing 0.1% trifluoroacetic acid: 40 ° C.

  The metal complex dye of the general formula (5) and the metal complex dye of the general formula (6) contained in the metal complex dye composition containing D-17 as a main component were detected as the following structures. The counter ion of the acidic group is detected as a proton because it contains trifluoroacetic acid in the eluent, but in the metal complex composition, the counter ion may be a proton or tetrabutylammonium.

ＭＳ−ＥＳＩ ｍ／ｚ ： ９９１．１６３（Ｍ＋Ｈ）⁺
吸収極大波長は ５４２ｎｍ

MS-ESI m / z: 991.163 (M + H) ⁺
Absorption maximum wavelength is 542nm

ＭＳ−ＥＳＩ ｍ／ｚ ： ９５９．１９４ （Ｍ＋Ｈ）⁺
吸収極大波長は ５１５ｎｍ

MS-ESI m / z: 959.194 (M + H) ⁺
Absorption maximum wavelength is 515nm

  Metal complex dye composition of general formula (5) and metal complex dye of general formula (6) contained in metal complex dye composition containing D-11 as a main component and metal complex dye composition containing D-10 as a main component Both dyes were detected as the following structures. Although the counter ion of the acidic group contains trifluoroacetic acid in the eluent, it is detected as a proton. In the metal complex composition, the counter ion is proton or tetrabutylammonium.

ＭＳ−ＥＳＩ ｍ／ｚ ： ９７１．１９４ （Ｍ＋Ｈ）⁺
吸収極大波長は ５４０ｎｍ

MS-ESI m / z: 971.194 (M + H) ⁺
Absorption maximum wavelength is 540nm

ＭＳ−ＥＳＩ ｍ／ｚ ： ９３９．２２３ （Ｍ＋Ｈ）⁺
吸収極大波長は ５１３ｎｍ

MS-ESI m / z: 939.223 (M + H) ⁺
Absorption maximum wavelength is 513nm

4). Evaluation of solubility in dye solution 12 mg of each metal complex dye composition shown in Table 1 was dissolved in a mixed solvent of 50 mL of toluene and 50 mL of methanol in the dark and stirred with a stirring blade at 25 ° C. for 15 minutes. Obtained. The amount of dissolution of the metal complex dye represented by the general formula (1) in this solution is determined as described in 3. above. Quantification was carried out using the HPLC apparatus used in the method. The dissolution amount is 11.0 mg or more and 12.0 mg or less as A, 10.0 mg or more and less than 11.0 mg as B, 9.0 mg or more and less than 10.0 mg as C, and less than 9.0 mg as D, and A and B Was passed.

5. Evaluation of dye adsorptivity to semiconductor fine particle electrode
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts.
Next, 32 g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) is mixed with 100 mL of a mixed solvent having a volume ratio of water and acetonitrile of 4: 1, and a rotating / revolving mixing conditioner is prepared. The resulting mixture was uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion. This dispersion was applied to a transparent conductive film and heated at 500 ° C. to produce a semiconductor fine particle electrode.
Thereafter, similarly, a dispersion containing 40:60 (mass ratio) of silica particles and rutile-type titanium oxide is prepared. Formed body. Next, a carbon electrode was formed as a counter electrode.
Next, the glass substrate on which the insulating porous body was formed was immersed in an ethanol solution having the metal complex dye composition shown in Table 1 for 12 hours. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² .

(Adsorbability evaluation)
Among the semiconductor fine particle electrodes produced by the above method, 2.3 cm ² was immersed in each dye solution in the dark at 40 ° C. for 30 minutes. The semiconductor fine particle electrode after dye adsorption was desorbed with a 10% TBAOH methanol solution, and the initial adsorption amount of each dye was quantified by HPLC. The amount dissolved in this solution is determined as described in 3. above. It calculated | required by the method similar to HPLC used by the method of above. The adsorption amount was 1.0 mg or more as A, 0.9 mg or more and less than 1.0 mg as B, 0.7 mg or more and less than 0.9 mg as C, less than 0.7 mg as D, and A and B as acceptable.

6). Evaluation of photoelectric conversion efficiency of photoelectric conversion element (preparation of semiconductor fine particle electrode)
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts.
Next, 32 g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) is mixed with 100 mL of a mixed solvent having a volume ratio of water and acetonitrile of 4: 1, and a rotating / revolving mixing conditioner is prepared. The resulting mixture was uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion. This dispersion was applied to a transparent conductive film and heated at 500 ° C. to produce a semiconductor fine particle electrode.
Thereafter, similarly, a dispersion containing 40:60 (mass ratio) of silica particles and rutile-type titanium oxide is prepared. Formed body. Next, a carbon electrode was formed as a counter electrode.
Next, 4. The glass substrate on which the insulating porous material was formed was immersed in the dye solution shown in Table 1 prepared in step 12 for 12 hours. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² .
Thereafter, the semiconductor fine particle electrode was disposed opposite to the platinum sputtered FTO substrate through a 50 μm thick thermoplastic polyolefin resin sheet, and the resin sheet portion was melted by heat to fix the bipolar plate.
In addition, the electrolyte solution was injected from the injection port of the electrolyte solution previously opened in the platinum sputter | spatter electrode side, and it filled between electrodes. Furthermore, the peripheral part and the electrolyte solution injection port were finally sealed with an epoxy-based sealing resin, and a silver paste was applied to the current collecting terminal part to obtain a photoelectric conversion element.
As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / L) and iodine (0.1 mol / L) was used.

(Evaluation of photoelectric conversion element)
The light of a 500 W xenon lamp (manufactured by USHIO INC.) Was passed through an AM1.5 filter (manufactured by Oriel) and a sharp cut filter (Kenko L-42) to obtain simulated sunlight containing no ultraviolet rays. The light intensity was 89 mW / cm ² .
Alligator clips were connected to the conductive glass plate and platinum-deposited glass plate of the above-described photoelectrochemical cell, and each alligator clip was connected to a current-voltage measuring device (Keutley SMU238 type (trade name)). This was irradiated with simulated sunlight from the conductive glass plate side, and the generated electricity was measured with a current-voltage measuring device. The conversion efficiency of the photoelectrochemical cell thus determined is 9.0% or more as A, 8.0% or more and less than 9.0% as B, 7.0% or more and less than 8.0% as C, 7.0. Less than% is D, and A and B are acceptable.

As can be seen from Table 1, when there are too many metal complex dyes represented by general formula (5) or general formula (6), there is a problem in photoelectric conversion efficiency, and when these metal complex dyes are too few, It has been found that there are problems in the amount of dye dissolved, the amount of adsorption, and the photoelectric conversion efficiency.
On the other hand, the metal complex dye composition of the present invention was satisfactory in all properties.
If the content of the metal complex dye represented by the general formula (5) or the general formula (6) is large, the solubility tends to be improved. However, if the content of these metal complexes is more than 5.0%, the adsorption amount It is expected that the low-efficiency metal complex dye represented by the general formula (5) or the general formula (6) is preferentially adsorbed, and the conversion efficiency decreases accordingly. did.

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 (8)

A metal complex dye represented by the following general formula (1), a metal complex dye represented by the following general formula (5) and / or a metal complex dye represented by the following general formula (6),
The content of the metal complex dye represented by the general formula (5) and the metal complex dye represented by the general formula (6) is an area detected at 254 nm of HPLC (High Performance Liquid Chromatography). 5-5% of metal complex dye composition characterized by the above-mentioned.
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) ₂ · (CI ¹ ) _{m 3} General formula (1)
[In General Formula (1), M ¹ represents a metal atom, LL ¹ is a bidentate ligand represented by the following General Formula (2), and LL ² is represented by the following General Formula (3). This is a bidentate ligand. m1 represents 1. m2 represents 1. Z ¹ represents a ligand and is at least one selected from an isothiocyanato group, an isocyanato group and an isoselenocyanato group. CI ¹ represents a counter ion when a counter ion is necessary to neutralize the charge, and m3 is an integer of 0 or more. ]

In General formula ^{(2), R} 11 ~R ¹⁴ and ^R 21 ^{to R 24} independently represent an acidic group or a salt thereof, or a hydrogen ^atom, R 11 ^{to R 14} and ^R 21 ^{to R 24} are the same as or different from each other It may be. However, at least one of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ is an acidic group or a salt thereof. ]

[In General Formula (3), n1 and n2 independently represent an integer of 0 to 3, Y ¹ and Y ² independently represent a hydrogen atom or a heteroaryl group represented by the following General Formula (4). . However, Ar ¹ and Ar ² independently represent a heteroaryl group represented by the following general formula (4). ]

[In General Formula (4), R ^{31 to} R ³³ independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an alkynyl group, and at least one of R ^{31 to} R ³³ represents an alkyl group, an alkoxy group, or an alkynyl group. It is a group. X is a sulfur atom, an oxygen atom, a selenium atom or NR ⁴ , and R ⁴ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ]
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (Z ¹ ) (CN) · (CI ¹ ) _{m 3} General formula (5)
[In General Formula (5), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ]
M ¹ (LL ¹ ) _{m 1} (LL ² ) _m ² (CN) _2. (CI ¹ ) _{m 3} General formula (6)
[In General Formula (6), M ¹ , LL ¹ , LL ² , Z ¹ , CI ¹ , m1, m2, and m3 have the same meanings as in General Formula (1). ] In the general formula (1), LL ² is claim 1 metal complex dye composition wherein a is represented by the following general formula (7).

[In the general formula ^{(7), R} 41 ~R ⁴³ and ^R 51 ^{to R 53} are independently a hydrogen atom, an alkyl group, an alkoxy group or an alkynyl group. At least one of R ^{41 to} R ⁴³ is an alkyl group, an alkoxy group, or an alkynyl group. At least one of R ^{51 to} R ⁵³ is an alkyl group, an alkoxy group, or an alkynyl group. X ¹ and X ² are each independently a sulfur atom, an oxygen atom, a selenium atom or NR ⁷ , and R ⁷ is a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ] The metal complex dye composition according to claim 2, wherein X ¹ and X ² in the general formula (7) are sulfur atoms. The metal complex dye composition according to any one of claims 1 to 3, wherein the metal complex dye represented by the general formula (1) is represented by the following general formula (8).

In General formula ^{(8), R 61, R} 62 represents an alkyl group, an alkoxy group or an alkynyl group ^{independently,} A 1, ^{A 2} represents a carboxyl group or a salt thereof independently. ] The metal complex dye represented by the general formula (5) is represented by the following general formula (9), and the metal complex dye represented by the general formula (6) is represented by the following general formula (10). The metal complex dye composition according to any one of claims 1 to 4, wherein the composition is a metal complex dye composition.

[In General Formula (9), R ⁷¹ and R ⁷² independently represent an alkyl group, an alkoxy group, or an alkynyl group, and A ⁵ and A ⁶ independently represent a carboxyl group or a salt thereof.
In general formula (10), R ⁷³ and R ⁷⁴ independently represent an alkyl group, an alkoxy group or an alkynyl group, and A ⁷ and A ⁸ are each independently a carboxyl group or a salt thereof. ] The metal complex dye represented by the general formula (5) is represented by the following general formula (11), and the metal complex dye represented by the general formula (6) is represented by the following general formula (12). The metal complex dye composition according to any one of claims 1 to 5, wherein the composition is a metal complex dye composition.

[In general formula (11) and general formula (12), R < ⁸¹ > -R < ⁸⁴ > represents an alkynyl group independently. A ^{13 to} A ¹⁶ independently represent a carboxyl group or a salt thereof. ]   A photoelectric conversion element comprising the metal complex dye composition according to any one of claims 1 to 6 as a sensitizing dye.   A photoelectrochemical cell comprising the photoelectric conversion device according to claim 7.

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