JP5992581B2 - Photoelectric conversion element, photoelectrochemical cell, and metal complex dye used therefor - Google Patents

Description

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

  Various solar cells used for solar power generation have been developed. Solar cells made of compounds such as single crystal silicon, polycrystalline silicon, amorphous silicon, cadmium telluride and indium copper selenide have been the subject of major research and development, and some of them have been put into practical use. However, in order to widely spread these solar cells to applications such as household power supplies, it is necessary to manufacture them at low cost and secure raw materials. Further, it is also required to significantly shorten the energy payback time (EPT: recovery period of input energy). Furthermore, it is desired to reduce the weight of the element and to provide flexibility. In response to these needs, while silicon-based solar cells have become widespread, there is a possibility of increasing the area of the condensing part and reducing manufacturing costs, and it is possible to design molecules using molecular modifications to inorganic materials. The practical application of solar cells using organic materials that are lightweight or flexible has been studied.

  Under such circumstances, techniques relating to a dye-sensitized solar cell using a titanium dioxide porous thin film spectrally sensitized with a ruthenium complex dye as a working electrode have been proposed (see, for example, Patent Documents 1 and 2). A sensitizing dye in which a predetermined substituent is introduced into the bipyridine ligand has also been proposed (see Patent Documents 3 and 4).

US Pat. No. 4,927,721 US Patent Publication No. 2010/0258175 JP 2001-291534 A JP 2011-037788 A

By the way, N719 etc. are developed as a ruthenium complex pigment | dye used for the spectral sensitization of a photoelectric conversion element. The photoelectric conversion element using this shows high photoelectric conversion efficiency at the beginning of use. However, the decrease in conversion efficiency after use is large, and there is a problem in improving durability. Another problem is that the absorption in the visible range is weak. Further, according to the confirmation of the present inventor, the performance described in Patent Documents 3 and 4 is not sufficient (see Comparative Examples below), and further performance improvement is desired.
The present invention provides a photoelectric conversion element and a photoelectrochemical cell that are excellent in photoelectric conversion characteristics and excellent in durability (heat resistance, durability of continuous light irradiation upon forced addition of water), and a metal complex dye used in the photoelectric conversion element. For the purpose of provision.

［式中、Ｒ^１は炭素数３〜２０の分岐アルキル基を置換基として有する炭素数６〜２６のアリール基である。Ｒ ^２及びＲ^３は炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数０〜２０のアミノ基またはハロゲン原子を表す。ｎ１は０〜４の整数を表す。ｎ２は０〜３の整数を表す。Ｌ^ａ は共役鎖である。］

［式中、Ａｃはカルボキシ基、ホスホニル基、ホスホリル基、スルホ基、ホウ酸基およびこれらの塩から選ばれる酸性基を表す。］
〔２〕
前記式（１）の金属錯体色素が下記式（１−１）で表される〔１〕に記載の光電変換素子。

［式中、Ｒ^１、Ｒ^２ 、ｎ１、Ｌ ^ａ およびＡｃは、それぞれ前記式（１）におけるＲ ^１ 、Ｒ ^２ 、ｎ１、Ｌ ^ａ およびＡｃと同義である。］
〔３〕
前記連結基Ｌ^ａがエテニレン基である〔１〕または〔２〕に記載の光電変換素子。
〔４〕
前記Ｒ^１における前記の炭素数３〜２０の分岐アルキル基が第四級炭素原子を有するか、または第三級炭素原子を有し、該分岐アルキル基の側鎖を構成するアルキル基の炭素数が２以上である〔１〕〜〔３〕のいずれか１項に記載の光電変換素子。
〔５〕
前記Ｒ ^１ が下記式（Ｒ１−１−１）で表される〔１〕〜〔４〕のいずれか１項に記載の光電変換素子。

［式中、Ｌ ^ｂ はアリーレン基を表す。Ｌ ^ｃ は−（ＣＨ _２ ）ｎ−で表される連結基を表し、ｎは０〜２の整数である。Ｒ ^１ａ は炭素数１〜４のアルキル基を表す。Ｒ ^１ｂ は炭素数１〜３のアルキル基を表す。Ｒ ^１ｃ は炭素数１〜４のアルキル基を表す。＊はＮに結合する結合手を表す。］
〔６〕
〔１〕〜〔５〕のいずれか１項に記載の光電変換素子を備えた光電気化学電池。
〔７〕
下記式（１）で表される金属錯体色素。
ＲｕＬ^１Ｌ^２Ｘ _２ ・ＣＩ （１）
［式（１）において、Ｌ ^１は下記式（Ｌ１−１）で表される配位子を表す。Ｌ²は下記式（Ｌ２−２）で表される配位子を表す。Ｘは１座の配位子を表す。ＣＩは、電荷を中和させるのに必要な場合の対イオンを表す。］

［式中、Ｒ^１は炭素数３〜２０の分岐アルキル基を置換基として有する炭素数６〜２６のアリール基である。Ｒ ^２及びＲ^３は炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数０〜２０のアミノ基またはハロゲン原子を表す。ｎ１は０〜４の整数を表す。ｎ２は０〜３の整数を表す。Ｌ^ａ は共役鎖である。］

［式中、Ａｃはカルボキシ基、ホスホニル基、ホスホリル基、スルホ基、ホウ酸基およびこれらの塩から選ばれる酸性基を表す。］
〔８〕
前記式（１）の金属錯体色素が下記式（１−１）で表される〔７〕に記載の金属錯体色素。

［式中、Ｒ ^１ 、Ｒ ^２ 、ｎ１、Ｌ ^ａ およびＡｃは、それぞれ前記式（１）におけるＲ ^１ 、Ｒ ^２ 、ｎ１、Ｌ ^ａ およびＡｃと同義である。］
〔９〕
前記連結基Ｌ ^ａ がエテニレン基である〔７〕または〔８〕に記載の金属錯体色素。
〔１０〕
前記Ｒ ^１ における前記の炭素数３〜２０の分岐アルキル基が第四級炭素原子を有するか、または第三級炭素原子を有し、該分岐アルキル基の側鎖を構成するアルキル基の炭素数が２以上である〔７〕〜〔９〕のいずれか１項に記載の金属錯体色素。
〔１１〕
前記Ｒ ^１ が下記式（Ｒ１−１−１）で表される〔７〕〜〔１０〕のいずれか１項に記載の金属錯体色素。

［式中、Ｌ ^ｂ はアリーレン基を表す。Ｌ ^ｃ は−（ＣＨ _２ ）ｎ−で表される連結基を表し、ｎは０〜２の整数である。Ｒ ^１ａ は炭素数１〜４のアルキル基を表す。Ｒ ^１ｂ は炭素数１〜３のアルキル基を表す。Ｒ ^１ｃ は炭素数１〜４のアルキル基を表す。＊はＮに結合する結合手を表す。］ The above problem has been solved by the following means.
[1]
The upper conductive support, a photoelectric conversion device having a photoreceptor, a charge transfer material, a layered structure which is disposed a counter electrode having a layer of semiconductor fine particles obtained by adsorbing a metal complex color element, the metal A photoelectric conversion element using a metal complex dye represented by the following formula (1) as a complex dye.
Ru L ¹ L ² X ₂ · CI (1)
[In the formula ^{(1), L} 1 represents a ligand represented by the following formula (L1 -1). L ² represents a ligand represented by the following formula (L2 −2 ). X represents a monodentate ligand . CI represents the counter ion as necessary to neutralize the charge. ]

[Wherein, R ¹ is an aryl group having 6 to 26 carbon atoms having a branched alkyl group having 3 to 20 carbon atoms as a substituent . R ² and R ³ represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, or a halogen atom. n1 represents an integer of 0 to 4. n2 represents an integer of 0 to 3. L ^a is a co-role chain. ]

[In the formula, Ac represents an acidic group selected from a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and salts thereof . ]
[2]
The photoelectric conversion element according to [ 1], wherein the metal complex dye of the formula (1) is represented by the following formula (1-1).

^{Wherein, R 1, R 2, n} 1, L a and Ac have the same meanings as ^{R 1, R 2, n1,} L a and Ac in each of the formulas (1). ]
[3]
The photoelectric conversion device according to the linking group L ^a is a ethenylene group (1) or (2).
[4]
The branched alkyl group having 3 to 20 carbon atoms in R ¹ has a quaternary carbon atom or a tertiary carbon atom, and the carbon number of the alkyl group constituting the side chain of the branched alkyl group The photoelectric conversion element according to any one of [1] to [ 3 ], wherein is 2 or more.
[5]
The photoelectric conversion element according to any one of [1] to [4], wherein R ¹ is represented by the following formula (R1-1-1).

[ Wherein , L ^b represents an arylene group. L ^c represents a linking group represented by — (CH ₂ ) n — , and n is an integer of 0 to 2. R ^1a represents an alkyl group having 1 to 4 carbon atoms. R ^1b represents an alkyl group having 1 to 3 carbon atoms. R ^1c represents an alkyl group having 1 to 4 carbon atoms. * Represents a bond bonded to N. ]
[6]
[1] A photoelectrochemical cell comprising the photoelectric conversion element according to any one of [ 5 ].
[7]
A metal complex dye represented by the following formula (1).
Ru L ¹ L ² X ₂ · CI (1)
[In the formula ^{(1), L} 1 represents a ligand represented by the following formula (L1 -1). L ² represents a ligand represented by the following formula (L2 −2 ). X represents a monodentate ligand . CI represents the counter ion as necessary to neutralize the charge. ]

[Wherein, R ¹ is an aryl group having 6 to 26 carbon atoms having a branched alkyl group having 3 to 20 carbon atoms as a substituent . R ² and R ³ represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, or a halogen atom. n1 represents an integer of 0 to 4. n2 represents an integer of 0 to 3. L ^a is a co-role chain. ]

[In the formula, Ac represents an acidic group selected from a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and salts thereof . ]
[8]
The metal complex dye according to [7], wherein the metal complex dye of the formula (1) is represented by the following formula (1-1).

^{Wherein, R 1, R 2, n1,} L a and Ac have the same meanings as ^{R 1, R 2, n1,} L a and Ac in each of the formulas (1). ]
[9]
Metal complex dye according to the linking group L ^a is a ethenylene group [7] or [8].
[10]
The branched alkyl group having 3 to 20 carbon atoms in R ¹ has a quaternary carbon atom or a tertiary carbon atom, and the carbon number of the alkyl group constituting the side chain of the branched alkyl group The metal complex dye according to any one of [7] to [9], wherein is 2 or more.
[11]
The metal complex dye according to any one of [7] to [10], wherein R ¹ is represented by the following formula (R1-1-1).

[ Wherein , L ^b represents an arylene group. L ^c represents a linking group represented by — (CH ₂ ) n — , and n is an integer of 0 to 2. R ^1a represents an alkyl group having 1 to 4 carbon atoms. R ^1b represents an alkyl group having 1 to 3 carbon atoms. R ^1c represents an alkyl group having 1 to 4 carbon atoms. * Represents a bond bonded to N. ]

  In this specification, the aromatic ring is used to mean including an aromatic ring and an aromatic heterocyclic ring. The carbon-carbon double bond may be any of E type and Z type in the molecule. When there are multiple substituents indicated by a specific symbol, or when multiple substituents and ligands (including the number of substituents) are specified simultaneously or alternatively, each substituent or ligand, etc. May be the same as or different from each other. Further, when a plurality of substituents or ligands are close to each other, they may be connected to each other or condensed to form a ring.

  The photoelectric conversion element and the photoelectrochemical cell of the present invention are excellent in photoelectric conversion characteristics and excellent in durability (heat resistance, continuous light irradiation durability during forced addition of water). Further, the metal complex dye of the present invention is novel and useful as a sensitizing dye for the photoelectric conversion element and the photoelectrochemical cell.

It is sectional drawing shown typically about one embodiment of the photoelectric conversion element of this invention. It is sectional drawing which shows typically the electrode substrate produced in the Example. It is sectional drawing which shows typically the dye-sensitized solar cell produced in the Example. It is sectional drawing which showed typically the modification of the photoelectric conversion element shown in FIG. 1 in the enlarged part (in a circle).

The metal complex dye used in the photoelectric conversion element of the present invention has a ligand having a specific branched alkyl group with respect to the central metal, thereby realizing high photoelectric conversion efficiency and improved durability.
This reason includes an unclear point, but can be explained as follows. The approach of water, which is one of the causes for the separation of the dye from the oxide semiconductor, can be efficiently suppressed by the branched alkyl chain. As a result, heat resistance and durability in the presence of water are considered to have improved. In addition, by introducing the branched alkyl chain to the substituent on the N-position, inefficient association can be suppressed, and in particular, a great effect can be obtained in terms of improving the durability. Hereinafter, the present invention will be described in detail with a focus on preferred embodiments thereof.

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

The light-receiving electrode 5 is an electrode composed of a conductive support 1 and a photosensitive layer (semiconductor film) 2 including semiconductor fine particles 22 adsorbed with a dye 21 coated on the conductive support. Light incident on the photoreceptor layer (semiconductor film) 2 excites the dye. The excited dye has high energy electrons. Therefore, the electrons are transferred from the dye 21 to the conduction band of the semiconductor fine particles 22 and further reach the conductive support 1 by diffusion. At this time, the molecule of the dye 21 is an oxidant. While the electrons on the electrode work in the external circuit, the excited and oxidized dye receives electrons from the reducing agent (eg, I ⁻ ) in the electrolyte and returns to the ground state dye, thereby allowing the photoelectrochemical cell to Acts as At this time, the light receiving electrode 5 functions as a negative electrode of the battery.

The photoelectric conversion element of this embodiment has a photoreceptor having a layer of porous semiconductor fine particles on which an after-mentioned dye is adsorbed on a conductive support. At this time, a part of the dye dissociated in the electrolyte may be present. The photoreceptor is designed according to the purpose, and may have a single layer structure or a multilayer structure. The photoconductor of the photoelectric conversion element of the present embodiment includes semiconductor fine particles adsorbed with a specific sensitizing dye, has high sensitivity, and can be used as a photoelectrochemical cell, and high conversion efficiency can be obtained.
The upper and lower sides of the photoelectric conversion element do not need to be defined in particular, but in this specification, based on what is illustrated, the support body serving as the light receiving side with the counter electrode 4 side as the upper (top) direction The side of 1 is the lower (bottom) direction.

[Dye represented by Formula (1)]
The coloring matter of the present invention is represented by the following formula (1).
ML ¹ L ² X _mX · CI (1)

* M represents a metal atom.
M represents a metal atom. M is preferably a metal capable of 6 coordination, more preferably Ru, Fe, Os, W, Cr, Mo, Ni, P t, Co, Ir, Rh, Re, is Mn or. Particularly preferred are Ru and Os, and most preferred is Ru.

* L ¹
L ¹ represents a ligand represented by the following formula (L1). However, it may be an electronic state appropriate for coordination, and may be interpreted as an appropriate state as a ligand, such as being an anion.

・ R ¹
In the formula, R ¹ is an alkyl group or an aromatic ring group. At least one of two R ¹ N positions represents an aromatic ring group branched alkyl group or a branched alkyl is substituted. Examples of the aromatic ring group include an aromatic group or an aromatic heterocyclic group exemplified in Substituent T described below, and among them, a benzene ring, a naphthalene ring, a thiophene ring, a selenophene ring, and the like are preferable. R1 in the same characteristic group may be the same or different and may form a ring with each other.
More preferably, the branched alkyl chain in R ¹ has a quaternary carbon atom or a tertiary carbon atom, and the alkyl group in the side chain thereof has 2 or more carbon atoms.

R ¹ is preferably represented by the following formula (R1-1).

In formula, R ^<1a> , R ^<1b> represents an alkyl group. R ^1c represents a hydrogen atom or an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms. When R ^1c is a hydrogen atom, R ^1b is preferably an alkyl group having 1 to 4 carbon atoms, and R ^1a has preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, and particularly preferably 2 to 4 carbon atoms. When R ^1c is an alkyl group, R ^1b is preferably an alkyl group having 1 to 3 carbon atoms, R ^1a preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms. It is. When n11 is 2 or more, the total carbon number of R ^1b and R ^1c existing in a plurality is preferably 2 to 10, more preferably 2 to 7, particularly preferably 2 to 5. * Represents a bond bonded to N. L ^b is a single bond or an aromatic ring group. Examples of the aromatic ring group include an aryl group and a heterocyclic group of the substituent T described later. L ^c is a linking group represented by — (CH ₂ ) n —, n is an integer of 0 or more, and preferably an integer of 0 to 2. However, the main chain and ^{(L c -C) n 11 -R} 1a. n11 is an integer of 1 or more. When n11 is 2 or more, a plurality of L ^c , R ^1b and R ^1c may be the same or different.

R ² and R ³
R ² and R ³ represent an alkyl group, an alkoxy group, an amino group, or a halogen atom. Preferred examples of the alkyl group, alkoxy group, amino group, or halogen atom include the examples of the substituent T described later.

・ N1, n2
n1 represents an integer of 0 to 4. n2 independently represents an integer of 0 to 3.

· ^{L a}
L ^a is a single bond or a conjugated chain, and preferred examples of the conjugated chain include the examples of L ^c and L ^d described later.

・ E
E represents a nitrogen atom or CH. m1 represents 0 or 1. However, when E is CH, the ligand of formula L1 becomes an anion and coordinates to the central metal.

* L ²
L ² represents a ligand represented by the following formula (L2).

・ Za, Zb and Zc
In the formula, Za, Zb and Zc each independently represent an atomic group forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.

  Za, Zb and Zc each independently represent a nonmetallic atom group capable of forming a 5-membered ring or a 6-membered ring. The formed 5-membered or 6-membered ring may be substituted or unsubstituted, and may be monocyclic or condensed. Za, Zb and Zc are preferably composed of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom and / or a halogen atom, and preferably form an aromatic ring. In the case of a 5-membered ring, an imidazole ring, an oxazole ring, a thiazole ring or a triazole ring is preferably formed. In the case of a 6-membered ring, a pyridine ring, a pyrimidine ring, a pyridazine ring or a pyrazine ring is preferably formed. Of these, an imidazole ring or a pyridine ring is more preferable.

Acidic group In the present invention, an acidic group is a substituent having a dissociative proton, such as a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, or a group having any one of these. Preferably, it is a carboxy group or a group having this. Further, the acidic group may take a form of releasing a proton and dissociating, or may be a salt. The acidic group is preferably a carboxy group, a sulfonic acid group, a phosphonyl group, a phosphoryl group, or a salt thereof. The acidic group may be a group bonded through a linking group. For example, a carboxyvinylene group, a dicarboxyvinylene group, a cyanocarboxyvinylene group, a carboxyphenyl group, and the like can be mentioned as preferable examples. In addition, the acidic group mentioned here and its preferable range may be called acidic group Ac. In addition, as above-mentioned, acidic group Ac should just be a group which has group which shows acidity, in other words, group which shows acidity may be introduce | transduced via the predetermined | prescribed coupling group. The acidic group may exist as a salt thereof. Although it does not specifically limit as a counter ion when it becomes a salt, For example, the example of the positive ion in the following counter ion CI is mentioned.

・ C1
c1 represents 0 or 1.

  L2 in the formula (1) is preferably represented by the following formula (L2-1).

  Ac represents the acidic group. c1 is synonymous with Formula L2.

It is preferable that the pigment of the formula (1) is represented by the following formula (1-1) or formula (1-2).
More preferably, it is represented by the following formula (1-1).

In the formula, R ¹ , R ² , R ³ , n1, n2, L ^a , and Ac have the same meanings as those in the formula (1).

* Ligand X
X represents a monodentate or bidentate ligand. Among them, acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithiocarbonate group, acyl group, thiocyanate group, A monodentate ligand coordinated by a group selected from the group consisting of isothiocyanate group, cyanate group, isocyanate group, selenate group, isoselenate group, cyano group, alkylthio group, arylthio group, alkoxy group and aryloxy group, Alternatively, a monodentate ligand selected from the group consisting of a halogen atom, phosphine, carbonyl, dialkyl ketone, carbonamide, thiocarbonamide, and thiourea is preferable.
Also, acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithiocarbonate group, acyl group, alkylthio group, A bidentate ligand coordinated by a group selected from the group consisting of an arylthio group, an alkoxy group and an aryloxy group, or 2 selected from the group consisting of 1,3-diketone, carbonamide, thiocarbonamide, and thiourea Preferably it represents a ligand of the locus.
In addition, when the ligand X contains an alkyl group, an alkenyl group, an alkynyl group, an alkylene group or the like, these may be linear or branched, and may be substituted or unsubstituted. Moreover, when an aryl group, a heterocyclic group, a cycloalkyl group, etc. are included, they may be substituted or unsubstituted, and may be monocyclic or condensed.

・ MX
M3 representing the number of ligands X is 1 or 2.

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

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

Specific examples of the ligand L ¹ are shown below, but the present invention is not limited to these. In the following specific examples, as a ligand constituting the metal complex, the structure such as the proton emission state and the state of charge may be interpreted appropriately, and the invention is not limited to this. Absent. In addition, although the counter ion is abbreviate | omitted in the following formula, arbitrary things may be accompanied.

Specific examples of the ligand L ² are shown below, but the present invention is not limited to these. In the following specific examples, the state in which the acidic group does not release protons is described as the ligand constituting the metal complex. Therefore, the present invention should not be interpreted in a limited manner.

Although the specific example of a metal complex dye is shown below, this invention is limited to this and is not interpreted.

  Specific examples of the compound represented by the formula (1) are shown below, but the present invention is not construed as being limited thereto.

  The synthesis of the dye composed of the compound represented by the formula (1) can be carried out with reference to the methods described in Examples below.

  The maximum absorption wavelength of the longest wavelength of the compound represented by the formula (1) is not particularly limited, but is preferably 500 nm or more, and more preferably 500 to 600 nm.

When using the metal complex dye of this invention for the below-mentioned photoelectric conversion element, it may be used independently or may be used together with another dye. Among these dyes, at least one dye (a dye used in combination with a dye other than the metal complex dye represented by the formula (1) of the present invention) has a maximum absorption wavelength on the longest wavelength side of 0.34 mmol / L tetrabutyl. It is preferable that it is 600 nm or more in an ammonium hydroxide methanol solution.
By combining with a dye that performs photoelectric conversion more efficiently on the longer wave side than the metal complex dye represented by the formula (1) of the present invention, sunlight can be efficiently photoelectrically converted. The dye to be combined is preferably a porphyrin dye, squarylium dye, phthalocyanine dye, more preferably a porphyrin dye or squarylium dye, and particularly preferably a squarylium dye. Among the porphyrin dyes, a binuclear complex is preferable, and among the squarylium dyes, bis-squarylium having two squarylium skeletons is preferable.
(Dye made of compound of formula (2))
By using together with other metal complex dyes other than the above-mentioned dyes, the mutual adsorption state can be controlled, and higher efficiency and durability than each can be achieved.

It is preferable that the other metal complex dye includes a dye made of a compound represented by the following formula (2).
MzL ³ _m3 L ⁴ _m4 Y _mY · CI (2)

・ Metal atom Mz
Mz is synonymous with M in Formula (1).

* L ³ (Formula (L3))
L ³ represents a bidentate ligand represented by the following formula (L3).

・ M3
m3 is an integer of 0 to 3, preferably 1 to 3, and more preferably 1. When m3 is 2 or more, L ³ may be the same or different.

・ Ac
Each Ac independently represents an acidic group. The preferable thing of Ac is synonymous with what was defined by Formula (1). Ac may be substituted on the pyridine ring or any atom of the substituent.

・ R ^a
R ^a each independently represents a substituent, and an example of the substituent T can be given. Preferably an alkyl group, alkenyl group, cycloalkyl group, aryl group, heterocyclic group, alkoxy group, aryloxy group, alkoxycarbonyl group, amino group, acyl group, sulfonamido group, acyloxy group, carbamoyl group, acylamino group, cyano Group or a halogen atom, more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a halogen atom, particularly preferably an alkyl group, an alkenyl group, An alkoxy group, an alkoxycarbonyl group, an amino group, or an acylamino group.

・ R ^b
R ^b represents an alkyl group or an aromatic ring group. The aromatic group is preferably an aromatic group having 6 to 30 carbon atoms, such as phenyl, substituted phenyl, naphthyl, and substituted naphthyl. The heterocyclic (heterocyclic) group is preferably a heterocyclic group having 1 to 30 carbon atoms, such as 2-thienyl, 2-pyrrolyl, 2-imidazolyl, 1-imidazolyl, 4-pyridyl, and 3-indolyl. . Preferably it is a heterocyclic group having 1 to 3 electron donating groups, more preferably thienyl. The electron donating group is preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, an acylamino group or a hydroxy group, and an alkyl group, an alkoxy group, an amino group or a hydroxy group. Is more preferable, and an alkyl group is particularly preferable.

・ E1, e2
e1 and e2 are integers of 0 to 5, preferably 0 to 3, and more preferably 0 to 2.

L ^c and L ^d
L ^c and L ^d each independently represent a conjugated chain, and represent a conjugated chain composed of an arylene group, a heteroarylene group, an ethenylene group and / or an ethynylene group. The ethenylene group, ethynylene group, and the like may be unsubstituted or substituted. When the ethenylene group has a substituent, the substituent is preferably an alkyl group, and more preferably methyl. L ^c and L ^d are each independently preferably a conjugated chain having 2 to 6 carbon atoms, more preferably thiophenediyl, ethenylene, butadienylene, ethynylene, butadienylene, methylethenylene or dimethylethenylene, Butadienylene is particularly preferred and ethenylene is most preferred. L ^c and L ^d may be the same or different, but are preferably the same. When the conjugated chain includes a carbon-carbon double bond, each double bond may be E-type or Z-type, or a mixture thereof.

・ E3
e3 is 0 or 1. In particular, when e3 is 0, the right f in the formula is preferably 1 or 2, and when e3 is 1, the right f is preferably 0 or 1. The total sum of f is preferably an integer of 0-2.

・ G
g represents the integer of 0-3 each independently, and it is preferable that it is an integer of 0-2.

・ F
f represents the integer of 0-3 each independently. When the sum of f is 1 or more and the ligand L ³ has at least one acidic group, m3 in the formula (2) is preferably 2 or 3, more preferably 2. . When f is 2 or more, Ac may be the same or different. In the formula, f on the left side is preferably 0 or 1, and f on the right side is preferably an integer of 0 to 2.

The ligand L ³ in the formula (2) is preferably represented by the following formula (L3-1), (L3-2) or (L3-3).

  In the formula, Ac, Ra, f, g and e3 have the same meanings as in the formula (L3). However, Ra substituted at the N-position may be a hydrogen atom. e4 is an integer of 0-4.

* L ⁴ (Formula (L4))
L ⁴ represents a bidentate or tridentate ligand represented by the following formula (L4).

In the formula (L4), Zd, Ze, and Zf represent an atomic group that can form a 5- or 6-membered ring. h represents 0 or 1; However, at least one of the rings formed by Zd, Ze, and Zf has an acidic group.
・ M4
m4 is an integer of 1 to 3, and preferably 1 or 2. m4 is the L ⁴ when two or more may be the same or different.

・ Zd, Ze, Zf
Zd, Ze, and Zf are synonymous with Za, Zb, and Zc of Formula (1).

・ H
h represents 0 or 1; h is preferably 0, and L ⁴ is preferably a bidentate ligand.

The ligand L ⁴ is preferably represented by any of the following formulas (L4-1) to (L4-8), and the formulas (L2-1), (L2-2), (L2-4), Or more preferably represented by (L2-6), particularly preferably represented by formula (L4-1) or (L4-2), and particularly preferably represented by formula (L4-1). .

  In formula, Ac represents an acidic group or its salt each independently. Ac is synonymous with Ac defined above.

In formula, ^Ra is synonymous with Formula (1). However, R ^a substituted at the N-position may be ^a hydrogen atom.

i independently represents the number of carbon positions (integer) that can be substituted by 0 or more. The number of possible substitutions is indicated by () next to the formula number. R ^a may be linked to each other or condensed to form a ring.

In the above formulas L4-1 to L4-8, the substituent Ra is shown with a bond extended to ^a predetermined aromatic ring, but is not limited to those substituted with the aromatic ring. That is, for example, in Formula L4-1, Ac and R ^a are substituted on the left pyridine ring, but these may be substituted on the right pyridine ring.

* Ligand Y
In formula (2), Y represents a monodentate or bidentate ligand. mY represents the number of ligands Y. mY represents an integer of 0 to 2, and mY is preferably 1 or 2. When Y is a monodentate ligand, mY is preferably 2. When Y is a bidentate ligand, mY is preferably 1. When mY is 2 or more, Y may be the same or different, and Y may be connected to each other.

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

When Y is a bidentate ligand, Y is an acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithio A ligand coordinated by a group selected from the group consisting of a carbonate group, an acyl group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a 1,3-diketone, carbonamide, thiocarbonamide, or thio A ligand composed of urea is preferable.
When Y is a monodentate ligand, Y is a ligand coordinated by a group selected from the group consisting of a thiocyanate group, an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, and an arylthio group, or A ligand composed of a halogen atom, phosphine, carbonyl, dialkyl ketone, or thiourea is preferable.

* Counter ion CI
CI in Formula (2) represents a counter ion when a counter ion is required to neutralize the charge. It is synonymous with CI in Formula (1), and its preferable range is also the same.

* Bonding group The dye having the structure represented by the formula (2) preferably has at least one suitable bonding group for the surface of the semiconductor fine particles. It is more preferable to have 1 to 6 bonding groups in the dye, and it is particularly preferable to have 1 to 4 bonding groups. Examples of the linking group include the aforementioned Ac.

  Specific examples of the dye having the structure represented by the formula (2) 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 release a proton, and may have arbitrary counter ions.

The dye represented by the formula (2) can be synthesized with reference to Japanese Patent Application Laid-Open No. 2001-291534 and the method cited in the publication.
The dye comprising the compound represented by formula (2) has a maximum absorption wavelength in the solution of preferably 300 to 1000 nm, more preferably 350 to 950 nm, and particularly preferably 370 to 900 nm. It is.
In the photoelectric conversion element and the photoelectrochemical cell of the present invention, a dye having a wide wavelength range can be obtained by using a dye composed of at least the compound represented by the formula (1) and a dye composed of the compound represented by the formula (2). By using light, high conversion efficiency can be ensured.

  The blending ratio of the dye consisting of the compound represented by the formula (2) and the dye consisting of the compound represented by the formula (1) is R / S = mole%, where R is the former and S is the latter. 95 / 5-10 / 90, preferably R / S = 95 / 5-50 / 50, more preferably R / S = 95 / 5-60 / 40, even more preferably R / S = 95 / 5-65 / 35, most preferably R / S = 95/5 to 70/30.

[Co-adsorbent]
In the photoelectric conversion element of this invention, it is preferable to use a coadsorbent with the metal complex dye of this invention, or the pigment | dye used together. As such a co-adsorbent, a co-adsorbent having a carboxyl group or a salt group thereof is preferable, and examples of the co-adsorbent include a compound having a fatty acid or a steroid skeleton. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid, and examples thereof include butanoic acid, hexanoic acid, octanoic acid, decanoic acid, hexadecanoic acid, dodecanoic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid.
Examples of the compound having a steroid skeleton include cholic acid, glycocholic acid, chenodeoxycholic acid, hyocholic acid, deoxycholic acid, lithocholic acid, ursodeoxycholic acid and the like. Preferred are cholic acid, deoxycholic acid and chenodeoxycholic acid, and more preferred are chenodeoxycholic acid.

  A preferred co-adsorbent is a compound represented by the following formula (A).

  In the formula, Ra represents a substituent. Examples of the substituent include the following substituent T.

  Ac represents an acidic group, and has the same meaning as described above.

  n represents an integer of 0 or more, and when n is 2 or more, the plurality of Rb may be the same or different from each other. n is preferably 2 to 4.

  Examples of these specific compounds include the compounds exemplified as the compounds having the above-mentioned steroid skeleton.

  The co-adsorbent of the present invention has the effect of suppressing inefficient association of dyes by adsorbing to semiconductor fine particles and the effect of preventing reverse electron transfer from the oxide semiconductor surface to the redox system in the electrolyte. The amount of the coadsorbent used is not particularly limited, but is preferably 1 to 200 mol, more preferably 10 to 150 mol, and particularly preferably 20 to 50 mol with respect to 1 mol of the sensitizing dye. It is preferable from the viewpoint of effectively expressing the action.

  In this specification, about the display of a compound (a complex and a pigment | dye are included), it uses for the meaning containing its salt, a complex, and its ion besides the said compound itself. Moreover, it is the meaning including the derivative modified with the predetermined form in the range with the desired effect. In addition, in the present specification, a substituent (including a linking group and a ligand) for which substitution / non-substitution is not specified means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substitution / non-substitution. Preferred substituents include the following substituent T.

Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl A group (preferably an alkenyl group having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms, such as ethynyl, butadiynyl, phenylethynyl, etc.), A cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), an aryl group (preferably an aryl group having 6 to 26 carbon atoms, for example, Phenyl, 1-naphthyl, 4-methoxyphenyl, -Chlorophenyl, 3-methylphenyl, etc.), heterocyclic groups (preferably heterocyclic groups having 2 to 20 carbon atoms, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2 -Oxazolyl, 2-thienyl and the like), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy and the like), an aryloxy group (preferably 6 to 26 carbon atoms). Aryloxy groups such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), alkoxycarbonyl groups (preferably alkoxycarbonyl groups having 2 to 20 carbon atoms such as ethoxycarbonyl, 2- Ethylhexyloxycarbonyl, etc.), amino group ( Preferably, an amino group having 0 to 20 carbon atoms, such as amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), a sulfonamide group (preferably having 0 to 0 carbon atoms). 20 sulfonamide groups, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc., acyloxy groups (preferably acyloxy groups having 1 to 20 carbon atoms, such as acetyloxy, benzoyloxy, etc.), carbamoyl A group (preferably a carbamoyl group having 1 to 20 carbon atoms such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms such as acetylamino, Benzoylamino, etc.), cyano group, or halogen atom (eg fluorine atom, salt) Elementary atoms, bromine atoms, iodine atoms, etc.), more preferably alkyl groups, alkenyl groups, aryl groups, heterocyclic groups, alkoxy groups, aryloxy groups, alkoxycarbonyl groups, amino groups, acylamino groups, cyano groups or halogens. An atom, particularly preferably an alkyl group, an alkenyl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group, or a cyano group.

  When a compound or a substituent includes an alkyl group, an alkenyl group, etc., these may be linear or branched, and may be substituted or unsubstituted. When an aryl group, a heterocyclic group, or the like is included, they may be monocyclic or condensed, and may be substituted or unsubstituted.

[Photoelectric conversion element]
(Photoreceptor layer)
The embodiment of the photoelectric conversion element has already been described with reference to FIG. In the present embodiment, the photoreceptor layer 2 is composed of a porous semiconductor layer composed of a layer of semiconductor fine particles 22 on which a dye described later is adsorbed. This dye may be partially dissociated in the electrolyte. The photoreceptor layer 2 may be designed according to the purpose and may have 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.

(Charge transfer body)
The electrolyte composition used for the photoelectric conversion element 10 of the present invention includes, for example, a combination of iodine and iodide (for example, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.) as an oxidation-reduction pair, alkyl Combinations of viologens (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and reduced forms thereof, combinations of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and oxidized forms thereof, bivalent and trivalent And iron complexes (for example, red blood salt and yellow blood salt) and combinations of divalent and trivalent cobalt complexes. 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 formula (1) is not an iodine salt, republished WO95 / 18456, JP-A-8-259543, Electrochemistry, Vol. 65, No. 11, page 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. Examples of the solvent include those described in JP-A No. 2001-291534.

  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)).

(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 is formed on a conductive support 1. 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.

  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.

(Semiconductor fine particles)
As shown in FIG. 1, in the photoelectric conversion element 10 of the present invention, a photosensitive layer 2 in which a sensitizing dye 21 is adsorbed on porous semiconductor fine particles 22 is formed on a conductive support 1. 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. In the present invention, the semiconductor fine particles prepared using the specific surfactant are applied.

(Semiconductor fine particle dispersion)
In the present invention, the semiconductor fine particle dispersion having a solid content other than the semiconductor fine particles of 10% by mass or less of the whole of the semiconductor fine particle dispersion is applied to the conductive support 1 and heated appropriately. Quality semiconductor fine particle coating layer can be obtained.

  In addition to the sol-gel method, semiconductor fine particle dispersions can be prepared by depositing fine particles in a solvent and using them as they are when synthesizing semiconductors. Or a method of pulverizing and grinding mechanically 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.

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 method for forming the film by applying the fine particle dispersion is not particularly limited, and a known method may be applied as appropriate.

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 solution 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. For example, ethanol, methanol, isopropanol, toluene, t-butanol, acetonitrile, acetone, n-butanol and the like can be used. Among these, ethanol and toluene can be preferably used.

The 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 becomes 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.

(Counter electrode)
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.

(Reception electrode)
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.

(Example)
Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereto.

<Preparation of exemplary dye>
(Preparation of Exemplified Compound D-1-3a)
Exemplified dye D-1-3a was prepared according to the method of the following scheme.

(I) Preparation of Compound d-3 27.4 g of aniline (d-1) and 76.9 g of potassium carbonate were stirred in 300 ml of N-methylpyrrolidone at room temperature, and 212 g of 2-ethylhexyl iodide was added dropwise at 80 ° C. After stirring for 2.5 hours, the mixture was stirred at 120 ° C. for 5 hours. Thereafter, 32.8 g of tert-butoxypotassium was added, and the mixture was stirred at 150 ° C. for 8 hours. After extraction and liquid separation with 350 ml of water and 400 ml of ethyl acetate, the organic layer was washed with 300 ml of water, and then the organic layer was concentrated and the crude product obtained was purified by silica gel column chromatography to obtain 78.2 g of compound d-3. Got.
(Ii) Preparation of d-4 While stirring 15.0 g of N, N-dimethylformamide at 0 ° C. in a nitrogen atmosphere, 18.9 g of phosphorus oxychloride was added dropwise. After stirring at room temperature for 30 minutes, 32.7 g of d-3 was added dropwise, followed by stirring at 60 ° C. for 30 minutes. Then, after cooling to room temperature, 300 ml of water was added, an aqueous solution in which 32 g of sodium hydroxide was dissolved in 150 ml of water was added and stirred for 15 minutes, 200 ml of ethyl acetate was added, and the precipitate was filtered. The filtrate was separated, and the organic layer was washed and separated with 100 ml of water, and then the organic layer was concentrated. The obtained crude product was purified by silica gel column chromatography to obtain 32.0 g of compound d-4.
(Iii) Preparation of d-6 d-5 2.24 g was dissolved in 100 ml of THF (terahydrofuran) at 0 ° C. in a nitrogen atmosphere, and separately prepared LDA (lithium diisopropylamide) was added to d-5. 1 equivalent was added dropwise and stirred for 75 minutes. Thereafter, a solution of 8.5 g of d-4 dissolved in 10 ml of THF was dropped, and the mixture was stirred at 0 ° C. for 1 hour and then stirred at room temperature for 2 hours. After adding 50 ml of a saturated aqueous ammonium chloride solution, liquid separation was performed, and the organic layer was concentrated. The obtained crude product was purified by silica gel column chromatography to obtain 9.7 g of compound d-6.

(Iv) Preparation of Compound d-7 4.3 g of d-6 and 2.4 g of PPTS (pyridinium paratoluenesulfonic acid) were added to 40 ml of toluene, and the mixture was heated to reflux for 7 hours in a nitrogen atmosphere. Liquid separation was carried out 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 3.6 g of d-7.

(IV) Preparation of Exemplified Dye D-1-3a 1.15 g of compound d-7 and 421 mg of d-8 were added to 60 ml of DMF and stirred at 70 ° C. for 4 hours. Thereafter, d-9 (336 mg) was added, and the mixture was heated with stirring at 150 ° C. for 7 hours. Thereafter, 3.7 g of ammonium thiocyanate was added and stirred at 130 ° C. for 5 hours. After concentration, 1.3 ml of water was added and washed with diethyl ether to obtain 1.7 g of a crude product. 1.5 g of the crude product was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide) and purified with a Sephadex LH-20 column. The main layer fraction was collected and concentrated, and then a 0.1 M aqueous solution of nitric acid was added. The precipitate was filtered and washed with water and diethyl ether to obtain 0.9 g of D-1-3b. 0.7 g of the purified product was dissolved in a methanol solution, a 1N nitric acid methanol solution was added, the precipitate was filtered, and washed with water and diethyl ether to obtain 650 mg of D-1-3a. In addition, after treating 300 mg of D-1-3b with a TBAOH methanol solution, water was added and the precipitate was filtered to obtain 280 mg of D-1-3c as a residue.

The structure of the obtained compound D-1-3a was confirmed by MS measurement.
MS-ESI m / z = 1299.6 (M−H) ⁺
About Exemplified Dye D-1-3a obtained, when the dye concentration was adjusted to 0.3 μmmol / L tetrabutylammonium hydroxide methanol solvent and the spectral absorption measurement was performed, the absorption maximum wavelength was It was 534 nm.

(Preparation of Exemplified Dye D-1-2a)
Exemplified dye D-1-2a was prepared in the same manner as Exemplified dye D-1-3a, except that d-2 of D-1-3a was changed to the following d-10.
The structure of the obtained compound D-1-2a was confirmed by MS measurement.
MS-ESI m / z = 1131.4 (M−H) ⁺
The obtained exemplary dye D-1-2a was prepared with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent so that the dye concentration was 17 μmol / l, and spectral absorption measurement was performed. It was 535 nm.

(Preparation of Exemplified Dye D-1-5a)
Exemplified dye D-1-5a was prepared in the same manner as Exemplified dye D-1-3a by changing d-2 of D-1-3a to the following d-11.
The structure of obtained compound D-1-5a was confirmed by MS measurement.
MS-ESI m / z = 1155.6 (M−H) ⁺
The obtained exemplary dye D-1-2a was prepared with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent so that the dye concentration was 17 μmol / l, and spectral absorption measurement was performed. It was 534 nm.

(Preparation of Exemplified Dye D-1-7a)
Exemplified dye D-1-7a was prepared in the same manner as Exemplified dye D-1-3a, except that d-4 of D-1-3a was changed to the following d-12.
The structure of the obtained compound D-1-7a was confirmed by MS measurement.
MS-ESI m / z = 1379.5 (M−H) ⁺
About the obtained exemplary dye D-1-7a, a dye concentration of 17 μmol / l was prepared with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and spectral absorption measurement was performed. It was 536 nm.

(Preparation of Exemplified Dye D-1-9a)
Exemplified dye D-1-9a was prepared in the same manner as Exemplified dye D-1-3a by changing d-4 of D-1-3a to the following d-13.
The structure of the obtained compound D-1-9a was confirmed by MS measurement.
MS-ESI m / z = 1375.4 (M−H) ⁺
The obtained exemplary dye D-1-9a was prepared with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent so that the dye concentration was 17 μmol / l, and spectral absorption measurement was performed. It was 540 nm.

(Preparation of Exemplified Dye D-1-11a)
Exemplified dye D-1-11a was prepared in the same manner as Exemplified dye D-1-3a, except that d-1 of D-1-3a was changed to the following d-14.
The structure of the obtained compound D-1-11a was confirmed by MS measurement.
MS-ESI m / z = 1359.6 (M−H) ⁺
About the obtained exemplary dye D-1-1a, the dye concentration was adjusted to 17 μmol / l with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and spectral absorption measurement was performed. It was 536 nm.

(Preparation of Exemplified Dye D-1-12a)
In accordance with the method of the following scheme, d-20 is prepared, d-7 of D-1-3a is changed to d-20 below, and hereinafter, Exemplified Dye D-1 is similar to Exemplified Dye D-1-3a. -12a was prepared.
(I) Preparation of Compound d-16 d-16 of D-1-3a was changed to the following d-15, and d-16 was synthesized in the same manner.
(Ii) Preparation of d-18 1.05 equivalent of 1.6M n-butyllithium hexane solution was added dropwise to 12.0 g of d-16 while stirring in 250 ml of THF at −78 ° C. in a nitrogen atmosphere. Thereafter, 1.5 equivalents of d-17 were added dropwise, the temperature was raised to -20 ° C, and the mixture was stirred for 1 hour. After the concentration, 10.4 g of compound d-18 was obtained by purifying the obtained crude product by silica gel column chromatography.
(Iii) Preparation of d-20 d-19 3 g, d-18 3 equivalents, tetrakistriphenylphosphine palladium (0) 10 mol%, cesium carbonate 5 equivalents in a nitrogen atmosphere at 0 ° C. in THF / water 5 / 1 While stirring in 40 ml of a mixed solvent, 30 mol% of tri-tert-butylphosphine was added. Thereafter, heating under reflux was performed for 8 hours. After concentration, liquid separation was performed with saturated aqueous sodium hydrogen carbonate and methylene chloride, the organic layer was washed with water, and after liquid separation, the organic layer was concentrated. The obtained crystals were recrystallized from methanol and methylene chloride to obtain 5.7 g of compound d-20.

The structure of the obtained compound D-1-12a was confirmed by MS measurement.
MS-ESI m / z = 1247.6 (M−H) ⁺
About the obtained exemplary dye D-1-12a, when the dye density | concentration was prepared so that it might become 17 micromol / l with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and the spectral absorption measurement was performed, the absorption maximum wavelength was It was 528 nm.

(Preparation of Exemplified Dye D-1-13a)
The dye D-1-13a was prepared in the same manner as the dye D-1-12a, except that the d-2 of D-1-12a was changed to the d-11 described above.
The structure of the obtained compound D-1-13a was confirmed by MS measurement.
MS-ESI m / z = 1303.6 (M−H) ⁺

  The obtained exemplary dye D-1-13a was prepared so that the dye concentration was 17 μmol / l with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and spectral absorption measurement was performed. It was 527 nm.

(Preparation of Exemplified Dye D-1-14a)
D-23 is prepared according to the method of the following scheme, and d-16 of D-1-12a is changed to the following d-23, and hereinafter, Exemplified Dye D-1 is similar to Exemplified Dye D-1-12a. -14a was prepared.

(I) Preparation of d-23 d-22 1.5 equivalents, d-22 1.5 equivalents, copper (I) iodide 1 equivalent, and potassium carbonate 3 equivalents in a nitrogen atmosphere, and 1,2-dichlorobenzene The mixture was stirred at 120 ° C. for 8 hours while stirring in 65 ml. After cooling to room temperature, the mixture was separated with aqueous sodium bicarbonate and ethyl acetate, the organic layer was washed with water and separated, and the organic layer was concentrated. The obtained crude product was purified by silica gel column chromatography to obtain 18.2 g of d-23. The structure of the obtained compound D-1-14a was confirmed by MS measurement.
MS-ESI m / z = 1327.4 (M−H) ⁺
The obtained exemplary dye D-1-14a was prepared so that the dye concentration would be 17 μmol / l with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and spectral absorption measurement was performed. It was 528 nm.

(Preparation of Exemplified Dye D-4-2a)
(I) Preparation of d-25 To 10.3 g of d-24, dissolved in 250 ml of THF (terahydrofuran) at 0 ° C. in a nitrogen atmosphere and separately prepared LDA (lithium diisopropylamide) was added to d-5. 1.1 equivalents of was added dropwise and stirred for 75 minutes. Then, d-4 1.1 equivalent of THF solution was added dropwise and stirred at 0 ° C. for 1 hour and then at room temperature for 2 hours. After adding 100 ml of saturated aqueous ammonium chloride solution, liquid separation was performed, and the organic layer was concentrated. The obtained crude product was purified by silica gel column chromatography to obtain 22.1 g of compound d-25.

(Ii) Preparation of Compound d-26 2 equivalents of PPTS (pyridinium paratoluenesulfonic acid) was added to 20 g of d-25 and heated under reflux for 7 hours in a nitrogen atmosphere. Liquid separation was carried out 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 18.2 g of d-26.
(Iii) Preparation of compound d-29 In addition to compound d-26 3.2 g, 0.5 equivalent of compound d-27 was added to 200 ml of NMP, and the mixture was stirred at 70 ° C. for 3 hours in a nitrogen atmosphere. Thereafter, 1 equivalent of d-28 was added and the mixture was heated and stirred at 160 ° C. for 8 hours. Thereafter, 20 equivalents of ammonium thiocyanate was added and stirred at 160 ° C. for 8 hours. After concentration, water was added and filtered to obtain d-29 5.2 g.
(Iv) Preparation of Exemplified Dye D-4-2a 1.0 g of d-29 was added to a mixed solvent of 30 ml of acetone and 40 ml of 1N aqueous sodium hydroxide solution, and stirred at an external temperature of 65 ° C. for 24 hours. The temperature was returned to room temperature, the pH was adjusted to 3 with hydrochloric acid, and the precipitate was filtered to obtain 560 mg of a crude product D-4-2a.
This was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide) and purified with a Sephadex LH-20 column. The main layer fraction was collected and concentrated, and then a 0.1 M trifluoromethanesulfonic acid solution was added to adjust the pH to 3, and the precipitate was filtered to obtain 400 mg of D-4-2a.
The structure of obtained compound D-4-2a was confirmed by MS measurement.
MS-ESI m / z = 1055.3 (M−H) ⁺
The obtained exemplary dye D-1-14a was prepared so that the dye concentration would be 17 μmol / l with 0.34 mmol / L tetrabutylammonium hydroxide methanol solvent, and spectral absorption measurement was performed. It was 587 nm.

(Preparation of Exemplified Dye D-4-2a)
Exemplified dye D-4-2a was similarly synthesized according to the following scheme.

(Preparation of Exemplified Dye D-7-1a)
(I) Preparation of compound d-31 In addition to 5.0 g of d-32, 1 equivalent of d-30 and 250 ml of ethylene glycol were heated under reflux for 1 hour under light-shielding conditions in a nitrogen atmosphere. Then, after adding 1 equivalent of d-9, it heated at 130 degreeC for 2 hours. Thereafter, the organic layer was washed with 250 ml of a saturated aqueous sodium hyposulfite solution, filtered, and washed with 100 ml of water and 100 ml of diethyl ether. After drying, d-31 was obtained.
(Ii) Preparation of Exemplified Dye D-7-1a To 4.2 g of d-31, 35 equivalents of potassium iodide was added to 270 ml of DMF and 135 ml of water, and the mixture was stirred at 140 ° C. for 3 hours. After concentration, the mixture was cooled to 3 ° C., 10 ml of water was added, and the mixture was washed with diethyl ether. The crude product was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide) and purified with a Sephadex LH-20 column. The main layer fraction was collected and concentrated, and then 0.2M nitric acid was added. The precipitate was filtered, washed with water and diethyl ether, dissolved again in methanol solution, and 1M nitric acid was added to precipitate. After filtration, it was washed with water and diethyl ether to obtain 3.4 g of D-7-1a.
The obtained compound D-7-1 was confirmed by MS measurement.
MS-ESI m / z: 1359.3 (M−H) ⁺

  The metal complex dye prepared by the above method is shown below. Those counter anions are optionally tetrabutylammonium ions.

Example 1
A test cell (i) of a dye-sensitized solar cell was produced by the following method, and the photoelectric conversion characteristics of this test cell were measured to obtain the conversion efficiency.
(Test cell (i))
A groove having a depth of 5 μm was formed in a lattice circuit pattern on the surface of a glass substrate 32 with a 100 × 100 mm FTO (fluorine-doped tin) film 34 by an etching method. Etching was performed using hydrofluoric acid after pattern formation by photolithography. A metal conductive layer (seed layer) was formed thereon by sputtering to enable plating formation, and a metal wiring layer 33 was further formed by additive plating. The metal wiring layer 33 was formed in a convex lens shape from the surface of the transparent substrate 32 to a height of 3 μm. The circuit width was 60 μm. From this, an FTO film having a thickness of 400 nm was formed as the shielding layer 35 by the SPD method, and an electrode substrate (i) was obtained. The cross-sectional shape of the electrode substrate (i) conforms to FIG. 2 in Japanese Patent Application Laid-Open No. 2004-146425. A schematic diagram of the electrode substrate (i) prepared here (reference numeral 31 in the figure) is shown in FIG.
A titanium oxide dispersion having an average particle size of 25 nm was applied and dried on the electrode substrate (i), and heated and sintered at 450 ° C. for 1 hour. This was immersed in an ethanol solution of the dye in the table for 40 minutes to carry the dye. It arrange | positioned facing a platinum sputter | spatter FTO board | substrate through a 50-micrometer-thick thermoplastic polyolefin resin sheet, the resin sheet part was heat-melted, and the bipolar plate was fixed. An electrolyte injection port was opened on the platinum sputter electrode side in advance, and a methoxyacetonitrile solution containing 0.5M iodide and 0.05M iodine as main components was injected between the electrodes as an electrolyte. . Furthermore, the peripheral part and the electrolyte solution injection port were finally sealed using an epoxy-based sealing resin, and a silver paste was applied to the current collecting terminal part to obtain a test cell (i). The following performance evaluation was performed for each test cell. The results are shown in Table 1 below.

(Test method)
A battery characteristic test was performed, and the conversion efficiency η was measured for the dye-sensitized solar cell. The battery characteristic test was performed by irradiating 1000 W / m ² of pseudo-sunlight from a xenon lamp through an AM1.5 filter using a solar simulator (manufactured by WACOM, WXS-85H). Current-voltage characteristics were measured using an IV tester to determine conversion efficiency (η /%). The following items were evaluated and judged. It is possible to obtain a high evaluation in the market if all are A or more.

(Initial conversion efficiency [η _i ])
AA: 7.5% or more A: 7.0% or more and less than 7.5% B: 6.5% or more and less than 7.0% C: Less than 6.5%

(Heat resistance test: rate of decrease in conversion efficiency after storage in the dark [γd])
The photoelectric conversion efficiency (η _f ) after aging at 80 ° C. for 500 hours was measured. Evaluation was performed by determining the rate of decrease (γd: the following formula) of η _f with _{respect to} the initial conversion efficiency (η _i ).
Formula: Rate of descent (γd) = (η _i −η _f ) / (η _i )
AA: γd is less than 5 A: γd is 5 or more and less than 10 B: γd is 10 or more and less than 20 C: γd is 20 or more

(Water resistance durability: Decrease rate of conversion efficiency after irradiation [γL])
The photoelectric conversion efficiency (η _g ) of the conversion efficiency after continuous light irradiation for 500 hours was measured. At this time, the forced addition of water was performed by adding 1% (v / v) water to the above electrolytic solution with respect to methoxyacetonitrile. Evaluation was performed by determining the rate of decrease (γL: the following equation) of the initial conversion efficiency (η _i ) of η _g .
Formula: Descent rate (γL) = (η _i −η _g ) / (η _i )
AA: γL is less than 10 A: γL is 10 or more and less than 15 B: γL is 15 or more and less than 20 C: γL is 20 or more

Comparative dye

  From the results shown in Table 1, it can be seen that the test cell using the metal complex dye of the present invention shows high conversion efficiency and superior heat resistance and durability in the presence of water compared to the case of using the comparative dye. It was.

(Example 2)
A dye-sensitized solar cell having the same configuration as that shown in FIG. 1 described in JP 2010-218770 A was prepared by the following procedure. A specific configuration is shown in FIG. 51 is a transparent substrate, 52 is a transparent conductive film, 53 is a barrier layer, 54 is an n-type semiconductor electrode, 55 is a p-type semiconductor layer, 56 is a p-type semiconductor film, and 57 is a counter electrode (57a is a protrusion of the counter electrode). .

Transparent conductive plate (Transparent Conductive Oxide: TCO) in which SnO ₂ : F (fluorine-doped tin oxide) as a transparent conductive film (52) is formed by CVD on a transparent glass plate as a transparent substrate (51) of 20 mm × 20 mm × 1 mm A glass substrate was prepared.
Next, 5 ml of a solution in which Ti (OCH (CH ₃ ) ₂ ) ₄ and water are mixed at a volume ratio of 4: 1 is mixed with 40 ml of an ethyl alcohol solution adjusted to pH 1 with hydrochloride, and the TiO ₂ precursor is mixed. A solution was prepared. Then, this solution is spin-coated on a TCO glass substrate at 1000 rpm and sol-gel synthesis is performed, followed by heating under vacuum at 78 ° C. for 45 minutes, and annealing at 450 ° C. for 30 minutes to form a titanium oxide thin film. A barrier layer (53) was formed.

On the other hand, anatase-type titanium oxide particles having an average particle size of 18 nm (particle size: 10 nm to 30 nm) are uniformly dispersed in a mixed solvent of ethanol and methanol (ethanol: methanol = 10: 1 (volume ratio)) to form titanium oxide. A slurry was prepared. At this time, the titanium oxide particles were uniformly dispersed using a homogenizer at a ratio of 10% by mass with respect to 100% by mass of the mixed solvent.
Next, a solution in which ethyl cellulose as a viscosity modifier is dissolved in ethanol so as to have a concentration of 10% by mass and an alcohol-based organic solvent (terpineol) are added to the titanium oxide slurry prepared above, and again And homogeneously dispersed with a homogenizer. Thereafter, alcohol other than terpineol was removed with an evaporator and mixed with a mixer to prepare a paste-like titanium oxide particle-containing composition. In addition, the composition of the prepared titanium oxide particle-containing composition was 20% by mass of titanium oxide particles and 5% by mass of the viscosity modifier, with the titanium oxide particle-containing composition being 100% by mass.

The titanium oxide particle-containing composition thus prepared was applied on the barrier layer (53) formed above so as to form a predetermined pattern by screen printing and dried at 150 ° C. Was heated to 450 ° C. to obtain a laminate in which an n-type semiconductor electrode (54) was laminated on a TCO glass substrate. Next, this laminate was immersed in a zinc nitrate (ZnNO ₃ ) solution overnight, and then heated at 450 ° C. for 45 minutes for surface treatment. Thereafter, the surface-treated laminate was immersed in the ethanol solution (concentration of sensitizing dye: 1 × 10 ⁻⁴ mol / L) using various dyes shown in Table 1, and left at 25 ° C. for 40 hours. Thus, the dye was adsorbed inside the n-type semiconductor electrode (14).

  Subsequently, CuI was added to acetonitrile to prepare a saturated solution, and 6 mg of the supernatant was taken out, and 15 mg of 1-methyl-3-ethylimidazolium thiocyanate was added to prepare a p-type semiconductor solution. . Then, on the hot plate heated to 80 ° C., the stacked body after the dye is contained in the n-type semiconductor electrode (54) is arranged, and the p-type semiconductor solution is pipetted onto the n-type semiconductor electrode (54). The p-type semiconductor layer (55) was produced by dropping and infiltrating the film and allowing it to stand for 1 minute and drying.

  Next, a copper plate having a thickness of 1 mm was washed with 1 M hydrochloric acid, and further washed with absolute ethanol, and then heated in the atmosphere at 500 ° C. for 4 hours to obtain a CuO nanowire having a maximum diameter of 100 nm and a height of 10 μm (protrusion 57a ) Was grown. This copper plate was sealed with iodine crystals in a sealed container and heated in a thermostatic bath at 60 ° C. for 1 hour to produce a counter electrode (57) having a thin CuI layer (p-type semiconductor film 56) coated on the surface. And this counter electrode (57) was pressed and laminated | stacked on the laminated body produced above from the p-type semiconductor layer (55) side.

  As a comparative example, an isopropanol solution containing 10% by mass of chloroplatinic acid is dropped on the surface of a TCO glass substrate similar to the above, dried, and heated at 400 ° C. to disperse Pt particles on the TCO glass substrate. A counter electrode was prepared and laminated on the p-type semiconductor layer (55) instead of the counter electrode (57).

The dye-sensitized solar cell thus produced was evaluated for performance in the same manner as in Example 1. As a result, in the element using the dye of the present invention, the initial conversion efficiency (ηi), heat resistance (decrease rate after storage in the dark) (γd), and water resistance (decrease rate after irradiation) (γL) are 2 at maximum. % Improvement effect was confirmed.
From these results, it was found that the metal complex dyes of the present invention showed good performance even with different types of photoelectric conversion elements, and further, the effect of improving the elements was also exhibited remarkably. Although the test evaluation was similarly performed about the pigment | dye of comparative example S-1-S-3, although an improvement effect is seen, compared with the element (Example) of this invention, all become a result inferior greatly. confirmed.

(Example 3)
The device performance was evaluated in the same manner as in Example 1 except that the dyes or coadsorbents used in Tables 2 and 3 were used. The amount of the metal complex dye was maintained as described above as a total amount, and the coexisting dye was contained at 30 mol% of the whole dye. The coadsorbent was added in an amount of 20 mol per 1 mol of the total amount of the dye. The following table shows the improvement effect of the initial conversion efficiency, the decrease rate after storage in the dark (heat resistance), and the decrease rate after irradiation (water resistance durability) according to the following criteria.

AA: An increase of 2% or more was observed. A: An increase of 0% or more and less than 2% was observed. B: A decrease in performance was observed.

  As can be seen from the above results, in the photoelectric conversion device of the present invention, it can be seen that a remarkable improvement effect appears by the coexistence of a specific coexisting dye or coadsorbent.

Example 4
The CdSe quantum dot process was performed on the photoelectrode by the following method, and the dye-sensitized solar cell shown in FIG. 4 was created using an electrolytic solution using a cobalt complex. FIG. 4 is an explanatory view schematically showing an enlarged photoconductor layer indicated by a circle in FIG. 1 as a modified example thereof.

An ethanol solution of titanium (IV) bis (acetylacetonate) diisopropoxide was sprayed 16 times on the surface of FTO glass (manufactured by Nippon Sheet Glass Co., Ltd., surface resistance: 8Ω sq ⁻¹ ), and baked at 450 ° C. for 30 minutes or more. . A transparent layer of about 2.1 μm with 20 nm-TiO ₂ and a light scattering layer of about 6.2 μm with 60 nm-TiO ₂ (manufactured by Showa Titanium Co., Ltd.) were laminated on this substrate by screen printing, and later with an aqueous TiCl ₄ solution. It performs processing to prepare a FTO / TiO ₂ film (2).

The FTO / TiO ₂ film was immersed in a 0.03M Cd (NO ₃ ) ₂ ethanol solution for 30 seconds in a glove bag under an inert gas atmosphere, and then continuously immersed in a 0.03M selenide ethanol solution for 30 seconds. Soaked. Then, it wash | cleaned in ethanol for 1 minute or more, the excess precursor was removed, and it dried. This dipping → cleaning → drying process was repeated five times to grow CdSe quantum dots (23) on the titanium oxide layer (22), and a surface stabilization treatment was performed with CdTe to produce a CdSe-treated photoelectrode.
Selenide (Se ²⁻ ) was adjusted in the system by adding 0.068 g of NaBH ₄ (to a concentration of 0.060M) to a 0.030M SeO ₂ ethanol solution under Ar or N ₂ atmosphere.

The CdS (23) -treated photoelectrode was immersed in a dye solution for 4 hours (ex.1 = 0.3 mM Z907Na acetonitrile / t-butanol (1: 1) solution and ex.2 = 0.1 mM SQ1 ethanol solution). After adsorbing the dye (21) to the photoelectrode, this photoelectrode and the counter electrode (4, a solution of hexachloroplatinic acid 2-propanol solution (0.05 M) on FTO glass chemically precipitated at 400 ° C. for 20 minutes) A 25 μm thick Surlyn (manufactured by DuPont) ring was sandwiched and assembled and sealed by heat melting. Electrolyte using cobalt complex (0.75 MCo (o-phen) ₃ ²⁺ , 0.075 M Co (o-phen) ₃ ³⁺ , 0.20 M LiClO ₄ acetonitrile / ethylene carbonate (4: 6 / v: v) Solution) is injected into the gap (3) between the electrodes from a hole previously formed on the side of the counter electrode, and then the hole is closed by heat with a binel sheet (made by DuPont) and a thin glass slide, and dye-sensitized. A solar battery cell (10) was produced. Note that o-phen is orthophenanthroline.
The cobalt complex added to the electrolytic solution was prepared by the method described in Chemical Communications, Vol. 46, pages 8788-8790 (2010).

  The dye-sensitized solar cell thus produced was evaluated for performance in the same manner as in Example 1. At this time, the improvement effect was observed for the initial conversion efficiency, the rate of decrease after dark storage (heat resistance), and the rate of decrease after irradiation (water resistance durability).

  As described above, it can be seen that the metal complex dye of the present invention shows a remarkable improvement effect in the device to which the photoelectrode and the Co complex electrolyte by CdSe treatment are applied. Although the test evaluation was similarly performed about the pigment | dye of comparative example S-1-S-3, although an improvement effect is seen, compared with the element (Example) of this invention, all become a result inferior greatly. confirmed.

In addition, a solar cell using the photoelectrode shown in FIG. 1 of JP-A-2004-152613, a solar cell using a tandem cell prepared in the same manner as in Example 1 of JP-A-2000-90989, A dye-sensitized solar cell shown in FIG. 1 of 2003-217688 was produced and tested in the same manner as described above. As a result, it was confirmed that good performance can be obtained with any of the dyes of the present invention.
In addition, the experiment in paragraphs (0053) to (0076) of JP-A-2002-367686, the experiment in paragraphs (0043) to (0055) of JP-A-2003-323818, and the paragraph (0073) of JP-A-2001-43907 are disclosed. To (0090), paragraphs (0014) to (0022) of JP 2000-340269, paragraphs (0022) to (0066) of JP 2005-85500, JP 2004-273272 Experiments in paragraphs (0014) to (0016), experiments in paragraphs (0155) to (0167) of JP 2000-323190 A, experiments in paragraphs (0137) to (0147) in JP 2000-228234 A, JP 2001 -266963, paragraphs (0085) to (0092), Japanese Patent Laid-Open No. 2001-185244 Experiments in paragraphs (0036) to (0045), experiment in Example 6 on pages 59 to 60 in JP 2001-525108 A, experiments in paragraphs (0023) to (0026) in JP 2001-203377 A, JP Experiments of paragraphs (0046) to (0054) of 2000-1000048, experiments of paragraphs (0043) to (0055) of JP-A-2001-210390, paragraphs (0080) to (0086) of JP-A-2002-280588 Experiments, experiments in paragraphs (0089) to (0104) of Japanese Patent Laid-Open No. 2001-273937, experiments in paragraphs (0160) to (0171) of Japanese Patent Laid-Open No. 2000-285777, paragraphs (0105) of Japanese Patent Laid-Open No. 2001-320068 to Good results were confirmed in the combination of the experiment of (0116) and the compound of the present invention.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Photoconductor layer 21 Dye 22 Semiconductor fine particle 23 CdSe quantum dot 3 Charge transfer body layer 4 Counter electrode 5 Photoreceptive electrode 6 Circuit 10 Photoelectric conversion element 100 Photoelectrochemical cell M Electric motor (electric fan)

31 Electrode substrate 32 Transparent substrate (glass substrate)
33 Metal wiring layer 34 Transparent conductive film (FTO film)
35 Shielding layer

41 transparent electrode 42 semiconductor electrode 43 transparent conductive film 44 substrate 45 semiconductor layer 46 light scattering layer 40 photoelectrode 20 dye-sensitized solar cell CE counter electrode E electrolyte S spacer 51 transparent substrate 52 transparent conductive film 53 barrier layer 54 n-type semiconductor electrode 55 p-type semiconductor layer 56 p-type semiconductor film 57 counter electrode 57a protrusion

Claims (11)

The upper conductive support, a photoelectric conversion device having a photoreceptor, a charge transfer material, a layered structure which is disposed a counter electrode having a layer of semiconductor fine particles obtained by adsorbing a metal complex color element, the metal A photoelectric conversion element using a metal complex dye represented by the following formula (1) as a complex dye.
Ru L ¹ L ² X ₂ · CI (1)
[In the formula ^{(1), L} 1 represents a ligand represented by the following formula (L1 -1). L ² represents a ligand represented by the following formula (L2 −2 ). X represents a monodentate ligand . CI represents the counter ion as necessary to neutralize the charge. ]

[Wherein, R ¹ is an aryl group having 6 to 26 carbon atoms having a branched alkyl group having 3 to 20 carbon atoms as a substituent . R ² and R ³ represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, or a halogen atom. n1 represents an integer of 0 to 4. n2 represents an integer of 0 to 3. L ^a is a co-role chain. ]

[In the formula, Ac represents an acidic group selected from a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and salts thereof . ] The photoelectric conversion element according to claim 1, wherein the metal complex dye of the formula (1) is represented by the following formula (1-1).

^{Wherein, R 1, R 2, n} 1, L a and Ac have the same meanings as ^{R 1, R 2, n1,} L a and Ac in each of the formulas (1). ] The photoelectric conversion device according to claim 1 or 2, wherein the linking group L ^a is a ethenylene group. The branched alkyl group having 3 to 20 carbon atoms in R ¹ has a quaternary carbon atom or a tertiary carbon atom, and the carbon number of the alkyl group constituting the side chain of the branched alkyl group The photoelectric conversion element according to any one of claims 1 to 3 , wherein is 2 or more. R ¹ The photoelectric conversion element according to any one of claims 1 to 4, wherein is represented by the following formula (R1-1-1).

[Where L ^b Represents an arylene group. L ^c Is-(CH ₂ ) Represents a linking group represented by n-, where n is an integer of 0-2. R ^1a Represents an alkyl group having 1 to 4 carbon atoms. R ^1b Represents an alkyl group having 1 to 3 carbon atoms. R ^1c Represents an alkyl group having 1 to 4 carbon atoms. * Represents a bond bonded to N. ] The photoelectrochemical cell provided with the photoelectric conversion element of any one of Claims 1-5 . A metal complex dye represented by the following formula (1).
Ru L ¹ L ² X ₂ · CI (1)
[In the formula ^{(1), L} 1 represents a ligand represented by the following formula (L1 -1). L ² represents a ligand represented by the following formula (L2 −2 ). X represents a monodentate ligand. CI represents the counter ion as necessary to neutralize the charge. ]

[Wherein, R ¹ is an aryl group having 6 to 26 carbon atoms having a branched alkyl group having 3 to 20 carbon atoms as a substituent . R ² and R ³ represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, or a halogen atom. n1 represents an integer of 0 to 4. n2 represents an integer of 0 to 3. L ^a is a co-role chain. ]

[In the formula, Ac represents an acidic group selected from a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and salts thereof . ] The metal complex dye according to claim 7, wherein the metal complex dye of the formula (1) is represented by the following formula (1-1).

[Wherein R ¹ , R ² , N1, L ^a And Ac are R in the formula (1), respectively. ¹ , R ² , N1, L ^a And Synonymous with Ac. ] The linking group L ^a The metal complex dye according to claim 7 or 8, wherein is an ethenylene group. R ¹ In which the branched alkyl group having 3 to 20 carbon atoms has a quaternary carbon atom or a tertiary carbon atom, and the alkyl group constituting the side chain of the branched alkyl group has 2 or more carbon atoms The metal complex dye according to any one of claims 7 to 9. R ¹ The metal complex dye according to any one of claims 7 to 10, wherein is represented by the following formula (R1-1-1).

[Where L ^b Represents an arylene group. L ^c Is-(CH ₂ ) Represents a linking group represented by n-, where n is an integer of 0-2. R ^1a Represents an alkyl group having 1 to 4 carbon atoms. R ^1b Represents an alkyl group having 1 to 3 carbon atoms. R ^1c Represents an alkyl group having 1 to 4 carbon atoms. * Represents a bond bonded to N. ]

Images