JP5620316B2 - Photoelectric conversion element, photoelectrochemical cell and dye - Google Patents

Description

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

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

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

Patent Document 1 describes a dye-sensitized photoelectric conversion element using semiconductor fine particles sensitized with a ruthenium complex dye by applying this technique. However, although conventional ruthenium complex dyes can be photoelectrically converted using visible light, they hardly absorb infrared light having a wavelength longer than 700 nm, and thus have a problem of low photoelectric conversion ability in the infrared region.
Therefore, there has been proposed to provide a photoelectric conversion element having a high conversion efficiency by increasing the light absorption at 800 nm by using a specific polymethine dye (for example, see Patent Documents 2 and 3). However, in these photoelectric conversion elements, the light absorption in the higher wavelength region and the photoelectric conversion efficiency in this wavelength region are not sufficient, and therefore it is required to improve the photoelectric conversion efficiency in the higher wavelength region. .
Therefore, there is a need for a photoelectric conversion element and a photoelectrochemical cell that can absorb light in a wavelength region exceeding 800 nm and obtain high conversion efficiency.

US Pat. No. 5,463,057 JP 2000-195570 A JP 2009-242379 A

  An object of the present invention is to provide a photoelectric conversion element, a photoelectrochemical cell, and a dye capable of obtaining high conversion efficiency even in a wavelength region exceeding 800 nm.

As a result of intensive studies, the present inventors have found that a polymethine dye having an electron-donating functional group at a specific site improves electron injection efficiency into semiconductor fine particles, and obtains high conversion efficiency even in a wavelength region exceeding 800 nm. I found that I can do it. The present invention has been made based on this finding.
The object of the present invention has been achieved by the following means.

<1> A photoelectric conversion element comprising a photosensitive layer having at least a dye composed of a compound represented by the following general formula (1) and semiconductor fine particles.

[In one general formula (1), Q is to display the tetravalent benzene or naphthalene, ^{X 1} and X ² is sulfur atom frames other independently represent a ^{C (R} 1) R ^2. Here, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R and R ′ each independently represents an aliphatic group . P ¹ and P ² are each independently a non-metallic atoms necessary or ^{P 30-1} below following general formula (3-1) is represented by ^{P 30-2} of the following general formula (3-2) Represents a group, P ¹ and P ² represent different structures. W ¹ represents a counter ion as necessary to neutralize the charge .
In lower following general formula (3-1) and ^{(3-2), P 30-1} or ^{P 30-2} is a ^{C * 31} is the terminal carbons, the general formula (1) ^{C * 1} and / or C ^{* 2} and carbon - are linked by carbon-carbon double bond. ]

［一般式（４−１）〜（４−３）において、Ｒａは水素原子または脂肪族基を表す。］
[In one general formula (3-1) and (3-2), A and B represents a benzene ring or a naphthalene ring. V ³¹ and ^{V 31 'is} a hydrogen atom, an alkyl group, an alkyloxy group, diphenylamino group, p- aminophenyl group, 5-carboxy, 6-carboxy group, 5-sulfonic acid, 5-phosphonyl group, It represents a 5-phosphoryl group or a salt thereof . n 31 and n31 'represents an integer of 1 or more. When n 31 is 2 or more, V ³¹ may be the same or different, and when n 31 ′ is 2 or more, V ^{31 ′} may be the same or different.
V ³¹ or V ^{31 'may} have with each other to form a ring. P ¹ or at least one of ^{V 31} and ^{V 31} Ru substituents der of ^{P 2 'is} an alkyl group, an alkyloxy group, .sigma.p in Hammett rule selected from a diphenylamino group and p- aminophenyl group The value represents a negative substituent. R ³⁴ and ^{R 34 'is} to display the group represented by an oxygen atom or the following general formula (4-1) to (4-3).
Y ³¹ and ^{Y 31 'is} sulfur atom frames other represents a ^{C (R} 6) R ^7. R ⁵ represents a hydrogen atom, an aliphatic group, an aromatic group, or represents a heterocyclic group bonded through a carbon atom. R ⁶ and R ⁷ are hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded through a carbon atom, may be the same or different, they may form a ring bonded to each other Good.
R ³¹ and R ^{31 'represents} an aliphatic group, an aromatic group, or represents a heterocyclic group bonded through a carbon atom, which may have a substituent.
R ^{32, R 32} to ^{', R 33} and R ^33' each independently represents a hydrogen atom or an aliphatic group, which may have a substituent. ]

[In the general formula (4-1) ~ (4-3), Ra is was or hydrogen atom an aliphatic group. ]

<2> The dye comprising the compound represented by the general formula (1) is selected from 5-carboxy group, 6-carboxy group, 5-sulfonic acid group, 5-phosphonyl group, 5-phosphoryl group and salts thereof The photoelectric conversion device according to <1> , which has an acidic group.
<3> before Symbol or an alkyl group of the general formula (1) ^{V 31} that put in and ^{V 31 ',} an alkyl group, .sigma.p value in Hammett rule selected from a diphenylamino group and p- aminophenyl group Has a negative substituent, and the other has an acidic group selected from a 5-carboxyl group, a 6-carboxy group, a 5-sulfonic acid group, a 5-phosphonyl group, a 5-phosphoryl group, and salts thereof. wherein <1> or the photoelectric conversion element according to <2>.
<4> the ^{R 34} or the ^{R 34 ',} before following general formula (4-1), characterized by being represented by - (4-3) <1> to to any one of <3> The photoelectric conversion element as described.

<5> the ^{R 34} or the ^{R 34 ',} the following general formula (5-1) or is characterized by being represented by (5-2) <1> to any one of <4> The photoelectric conversion element as described.

<6> pre Symbol ^{R 34} or ^{R 34 'is} characterized by an oxygen atom <1> to photoelectric conversion element according to any one of <3>.

< 7 > The photoelectric conversion device according to any one of <1> to < 6 >, wherein the photoreceptor layer contains a dye composed of a compound represented by the following general formula (6).
M z (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (6)
[In one general formula (6), Mz represents a metal atom, LL ¹ is bidentate or represented by the following general formula (7) represents a tridentate ligand, LL ² the following general formula (8 ) with bidentate or represented represents the tridentate ligand. X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, 1 seat or bidentate ligand coordinated with a group selected from the group consisting of an alkoxy group and an aryloxy group, or it represents a halogen atom, carbonyl, dialkyl ketone, 1,3-diketone, carbonamide, 1 seat or bidentate ligand selected from the group consisting of thio carboxylic amide and thiourea. m1 represents an integer of 0 to 3, and when m1 is 2 or more, LL ¹ may be the same or different. m2 represents an integer of 1 to 3, when m2 is 2 or more, LL ² may be the same or different. m3 represents an integer of 0 to 3, and when m3 is 2 or more, Xs may be the same or different, and Xs may be linked to each other. CI represents a counter ion when a counter ion is necessary to neutralize the charge in the general formula (6). ]

[In one general formula ^(7), each of ^{R 51} and ^{R 52} independently or acidic group represents a group having an acidic group. R ⁵³ and ^{R 54} each independently represents a ^substituent, each ^{R 55} and ^{R 56} are independently or an aryl group or a heterocyclic group. d1 and d2 each represent an integer of 0 to 5. To L ¹ and L ² are each independently, an ethenylene group and / or represents a conjugated chain composed of ethynylene group. a1 and a2 each independently represents an integer of 0 to 3, a1 is or different and is R ⁵¹ when two or more same, R ⁵² when a2 is 2 or more may be the same or different . b1 and b2 each independently represents an integer of 0 to 3, b1 is or different and is ^{R 53} when two or more ^{same, R 53} may be linked with each other to form a ring, b2 When R is 2 or more, R ⁵⁴ may be the same or different, and R ⁵⁴ may be linked together to form a ring. b1 Oyo When beauty b2 are both 1 or ^more, may be connected to form a ring ^{R 53} and ^{R 54.} d3 is 0 or represents 1. ]

[In one general formula (8), Za, are each Zb and Zc independently, 5-membered ring or represents a non-metal atomic group which can form a 6-membered ring, c is 0 or represents 1. Provided that at least one of the rings Za, Zb and Zc is formed having an acid group. ]

<8> In the general formula (7), the photoelectric conversion element according to <7>, wherein the d1 and d2 is an integer of 1 or more.
<9> the ^{R 55} or ^{R 56} is represented by the following general formula (9-1) is characterized in that either - (9-7) <7> or photoelectric conversion device according to <8> .

[One general formula (9-1) in ^{~ (9-7), R 59,} R 63, R 66, R 69 and ^{R 74} may the alkyl group which may have a substituent, an alkynyl group or an aryl group Represents. R ⁵⁷ , R ⁵⁸ , R ^{60 to} R ⁶² , R ⁶⁴ , R _h , R ⁶⁵ , R ⁶⁷ , R ⁶⁸ , R ^{70 to} R ⁷³ , R ⁷⁵ , R ⁷⁶ and R ^{78 to} R ⁸¹ are each independently hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a thioalkyl group, an aryl group, an aryloxy group, an arylthio group, an amino group, also heterocyclic group represents a halogen atom. R ⁵⁷ and ^{R 58, R} 60 ^{~R 62} and ^{R 64} and ^{R 65, R 67} and ^{R 68, R} 70 ^{~R 73} and ^{R 75} and ^{R 76} and ^R 78 ^{to R 81} are each ring May be formed. R ⁷⁷ and R ⁸² to present twice in the same characteristic group may be the same or different, represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or a heterocyclic group.
m1 to m6 each represents an integer of 1 to 5. Y and X are independently represents S, O, Se, and Te, or NR ^{83, R 83} represents a hydrogen atom, an alkyl group, an alkenyl group, an alkenyl group, an aryl group or a heterocyclic group. ]

< 10 > The structure according to any one of <1> to < 9 >, wherein the photosensitive layer, the charge transfer layer, and the counter electrode are stacked in this order on a conductive support. Photoelectric conversion element.
< 11 > The photoelectric conversion element according to any one of <1> to < 10 >, wherein the dye is adsorbed on the semiconductor fine particles.
< 12 > A photoelectrochemical cell comprising the photoelectric conversion element according to any one of <1> to < 11 >.
< 13 > A dye comprising at least a compound represented by the following general formula (1).

[In one general formula (1), Q is to display the tetravalent benzene or naphthalene, ^{X 1} and X ² is sulfur atom frames other independently represent a ^{C (R} 1) R ^2. Here, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R and R ′ each independently represents an aliphatic group . P ¹ and P ² are each independently a non-metallic atoms necessary or ^{P 30-1} below following general formula (3-1) is represented by ^{P 30-2} of the following general formula (3-2) Represents a group, P ¹ and P ² represent different structures. W ¹ represents a counter ion as necessary to neutralize the charge .
In lower following general formula (3-1) and ^{(3-2), P 30-1} or ^{P 30-2} is a ^{C * 31} is the terminal carbons, the general formula (1) ^{C * 1} and / or C ^{* 2} and carbon - are linked by carbon-carbon double bond. ]

［一般式（４−１）〜（４−３）において、Ｒａは水素原子または脂肪族基を表す。］
[In one general formula (3-1) and (3-2), A and B represents a benzene ring or a naphthalene ring. V ³¹ and ^{V 31 'is} a hydrogen atom, an alkyl group, an alkyloxy group, diphenylamino group, p- aminophenyl group, 5-carboxy, 6-carboxy group, 5-sulfonic acid, 5-phosphonyl group, It represents a 5-phosphoryl group or a salt thereof . n 31 and n31 'represents an integer of 1 or more. When n 31 is 2 or more, V ³¹ may be the same or different, and when n 31 ′ is 2 or more, V ^{31 ′} may be the same or different.
V ³¹ or V ^{31 'may} have with each other to form a ring. P ¹ or at least one of ^{V 31} and ^{V 31} Ru substituents der of ^{P 2 'is} an alkyl group, an alkyloxy group, .sigma.p in Hammett rule selected from a diphenylamino group and p- aminophenyl group The value represents a negative substituent. R ³⁴ and ^{R 34 'is} to display the group represented by an oxygen atom or the following general formula (4-1) to (4-3).
Y ³¹ and ^{Y 31 'is} sulfur atom frames other represents a ^{C (R} 6) R ^7. R ⁵ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R ⁶ and R ⁷ are hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded through a carbon atom, may be the same or different, they may form a ring bonded to each other Good.
R ³¹ and R ^{31 'represents} an aliphatic group, an aromatic group, or represents a heterocyclic group bonded through a carbon atom, which may have a substituent.
R ^{32, R 32} to ^{', R 33} and R ^33' each independently represents a hydrogen atom or an aliphatic group, which may have a substituent. ]

[In the general formula (4-1) ~ (4-3), Ra is was or hydrogen atom an aliphatic group. ]

  According to the present invention, a photoelectric conversion element and a photoelectrochemical cell having high conversion efficiency can be provided. In addition, the present invention can provide a sensitizing dye having high conversion efficiency.

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

  As a result of intensive studies, the present inventors have found that a polymethine dye having an electron-donating functional group at a specific site improves the electron injection efficiency into semiconductor fine particles, and obtains high conversion efficiency even in a wavelength region exceeding 800 nm. I found that I can do it. Although the detailed principle is not certain, it is estimated as follows. By having an electron-donating functional group at a specific part of the polymethine dye, localization of electrons (HOMO (highest occupied orbital) and LUMO (lowest orbital orbital bias)) is promoted, and the semiconductor fine particles Improve electron injection efficiency. Furthermore, by having an acidic group or the like at a site different from the site having an electron-donating functional group, the dye can be adsorbed to the semiconductor fine particles by this functional group, and reverse electron transfer from the semiconductor fine particles can be made difficult to occur. I think that the. Hereinafter, preferred embodiments of the present invention will be described in detail.

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

  The light-receiving electrode 5 is an electrode composed of a conductive support 1 and a photosensitive layer (semiconductor film) 2 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. The electrons on the electrode return to the oxidized dye while working in an external circuit, thereby acting as a photoelectrochemical cell. At this time, the light receiving electrode 5 functions as a negative electrode of the battery.

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

(A) Dye (A1) Dye made of compound of general formula (1) In the photoelectric conversion device of the present invention, a dye made of at least a compound represented by the following general formula (1) is used. The dye of the general formula (1) includes one in which one of the resonance structural formulas is represented by the general formula (1).

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

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

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

In the general formula (1), P ¹ and P ² are each independently P ^{20-1 in the following} general formula (2-1), P ^{20-2 in the following} general formula (2-2), and the following general formula (3 -1) represents a non-metallic atomic group necessary to be represented by P ^30-1 or P ^30-2 of the following general formula (3-2), and P ¹ and P ² represent different structures. W ¹ represents a counter ion as necessary to neutralize the charge.
However, in the present invention, P ¹ and P ² are nonmetals necessary for being represented by P ^30-1 of the following general formula (3-1) or P ^30-2 of the following general formula (3-2). It is an atomic group.
In the following general formulas (2-1) and (2-2), P ^20-1 or P ^20-2 is C ^{* 21} which is a terminal carbon, and C ^{* 1} and / or of the above general formula (1) It is bonded to C ^{* 2} by a carbon-carbon double bond.
In the following general formulas (3-1) and (3-2), P ^30-1 or P ^30-2 is C ^{* 31} , which is a terminal carbon, and C ^{* 1} and / or in the general formula (1). C * ² and a carbon - it is linked by a carbon double bond.

In the general formulas (2-1) and (2-2), V ²¹ and V ^{21 ′} , n21 and n21 ′, n22 and n22 ′, Y ²¹ and Y ^{21 ′} , R ²¹ and R ^{21 ′} , R ²² and R ^{22 ′} , R ²³ and R ^{23 ′} , and R ²⁴ and R ^{24 ′} are synonymous. Therefore, one of them will be described in the following description.
In the general formulas (3-1) and (3-2), V ³¹ and V ^{31 ′} , n31 and n31 ′, Y ³¹ and Y ^{31 ′} , R ³¹ and R ^{31 ′} , R ³² and R ^{32 '} , R ³³ and R ^33' and R ³⁴ and R ^{34 '} are synonymous, and therefore, in the following description, one of them will be described.
In the general formulas (2-1) to (3-2), A and B represent a benzene ring or a naphthalene ring. V ²¹ and V ³¹ represent a hydrogen atom or a substituent. n21 represents an integer of 1 or more, when n21 is 2 or ^{more, V 21} may be the same or different, when n31 is 2 or ^{more, V 31} may be the same or ^{different, V 21} or V ³¹ may be connected to each other to form a ring. V ²¹ and V ³¹ are preferably substituted at the para-position of the nitrogen atom to which R ²¹ or R ³¹ is bonded. The preferable range of n21 and n31 is 1 to 2, more preferably 1. At least one of P ^{1, V 21} or ^{V 31} is any substituent ^{P 2} is to table σp value a negative substituent in Hammett rule, in the present invention, an alkyl group, an alkyloxy group, diphenyl It is selected from an amino group and a p-aminophenyl group . R ³⁴ is an oxygen atom, a nitrogen atom or a carbon atom, and when R ³⁴ is a nitrogen atom, the nitrogen atom represents two groups selected from a substituent group consisting of a hydrogen atom, an aliphatic group and an aromatic group. And R ³⁴ is a carbon atom, the sum of the σp values in the Hammett rule of the substituent on the carbon atom is positive. n22 represents an integer of 0 or more. n22 is preferably 0 or 1.
However, in the present invention, V ³¹ is a hydrogen atom, an alkyl group, an alkyloxy group, a diphenylamino group, a p-aminophenyl group, a 5-carboxy group, a 6-carboxy group, a 5-sulfonic acid group, or a 5-phosphonyl group. , 5-phosphoryl group or a salt thereof. R ³⁴ is an oxygen atom or a group represented by general formulas (4-1) to (4-3) described later, and Ra is a hydrogen atom or an aliphatic group.

  Here, Hammett's substituent constant σp value will be described. Hammett's rule is a method described in 1935 by L. E. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. This is a rule of thumb advocated by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include σp value and σm value, and these values can be found in many general books. For example, J. et al. A. Dean, "Lange's Handbook of Chemistry", 12th edition, 1979 (McGraw-Hill) and "Area of Chemistry" extra edition, 122, 96-103, 1979 (Nankodo), Chem. Rev. 1991, 91, 165-195.

Examples of substituents having a negative Hammett σp value include methyl (σp = −0.17), methoxy (σp = −0.27), trimethylsilyloxy (σp = −0.27), tert-butyl (σp = −0.20), p-tolyl (σp = −0.03), dipropylamino (σp = −0.93), diphenylamino (σp = −0.22), and the like. In P ¹ or P ^2, it is considered that at least one V ¹ is a substituent having a negative σp value in Hammett's rule, thereby obtaining an effect of promoting localization of HOMO orbitals. V ¹ is preferably an alkyl group, an alkyloxy group, diphenylamino, p-aminophenyl, or the like. The values in parentheses are the σp values of typical substituents in Chem. Rev. 1991, Vol. 91, pp. 165-195.

In the general formulas (2-1) to (3-2), when R ³⁴ or R ^{34 ′} is a nitrogen atom, it is composed of a hydrogen atom, an aliphatic group, and an aromatic group as two substituents bonded to the nitrogen atom. Examples of the substituent group include the following. For example, selected from a hydrogen atom, methyl, ethyl, n-butyl, n-hexyl, izobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl or phenyl, tolyl, naphthyl, anthranyl, thienyl, furanyl, etc. . Examples of the carbon atom having two substituents and the sum of the σp values in the Hammett rule of the substituent being positive are, for example, a cyano group (σp = 0.66), a chloro group (σp = 0.23) ), Ester group (σp = 0.45), carboxylic acid group (σp = 0.45), sulfonic acid group (σp = 0.35), carbonamido group (σp = 0.36), trifluoromethyl group ( σp = 0.54). Among these, a cyano group, an ester group, a carboxylic acid group, and the like are preferable.

Y ²¹ and ^{Y 31} is a sulfur atom, NR ^5, or represents a ^CR 6 ^{R 7,} in the present invention, a sulfur atom or a ^CR 6 ^{R 7.} R ⁵ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. Preferred examples of R ⁵ are aliphatic groups (eg methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl etc.) or aromatic groups (eg phenyl , Tolyl, naphthyl, etc.). R ⁵ is more preferably an aliphatic group (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.).
R ⁶ and R ⁷ represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded by a carbon atom, and R ⁶ and R ⁷ may be the same or different, and are bonded to each other to form a ring. May be formed. Preferred examples of R ⁶ and R ⁷ are aliphatic groups or aromatic groups, and more preferably aliphatic groups (for example, methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.).

R ²¹ and R ³¹ represent an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom, and may have a substituent. Acidic group can be mentioned as preferred examples of the substituent, more preferably a group having a carboxy sheet group.
R ²² , R ³² , R ²³ , R ³³ and R ²⁴ each independently represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and may have a substituent, preferably hydrogen. An atom or an aliphatic group, more preferably a hydrogen atom.
However, in the present invention, R ³² and R ³³ are a hydrogen atom or an aliphatic group.

It is preferable that the pigment | dye represented by General formula (1) has an acidic group. In the dye of the present invention, it is preferable that at least one of R, R ′, P ¹ and P ² has an acidic group. More preferably, any of V ²¹ , V ^{21 ′} , V ³¹ and V ^{31 ′} in P ¹ and P ² has a substituent with a negative σp value in Hammett's rule, and the other preferably has an acidic group. . Examples of the substituent having a negative σp value in Hammett's rule in this case include the same as those for V ²¹ , V ^{21 ′} , V ³¹ or V ^{31 ′} . For example, an alkyloxy group, p-aminophenyl group, diphenylamino group, alkyl group and the like are preferable.
Here, the acidic group is a substituent having a dissociable proton, for example, carboxy shea group, a phosphonyl group, a sulfonyl group, and a group having a boric acid group, preferably a group having a carboxy sheet group is there. Further, the acidic group may take a form of releasing a proton and dissociating, or may be a salt. In V ^{1, the} above acidic group may be directly bonded to the benzene ring, or the acidic group may be bonded via a linking group. Acidic group in ^{V 21, V 21 ', V} 31 or ^{V 31'} are 5-carboxy sheet group, 6-carboxyl group, one 5-sulfonic acid, 5-phosphonyl group or 5-phosphoryl group or a salt thereof It is preferable that Here, the position number is given counterclockwise, with N ⁺ being 1.
In the present invention, the acidic group is selected from 5-carboxyl group, 6-carboxyl group, 5-sulfonic acid group, 5-phosphonyl group, 5-phosphoryl group and salts thereof.
The dye having the structure of the general formula (1) preferably has a structure of P ^30-1 . More preferably, it is preferable that both P ¹ and P ² have the structure of P ^30-1 .

R ³⁴ or R ^{34 ′} is preferably represented by the following general formulas (4-1) to (4-4).

In the general formulas (4-1) to (4-3), examples of the substituent in Ra include an aliphatic group, an aromatic group, and a heterocyclic group bonded with a carbon atom, preferably an aliphatic group. . Thereby, the effect which reinforces absorption by the short wavelength side can be show | played. The R ³⁴ or R ^{34 ′} is preferably represented by the following general formula (5-1) or (5-2). These dyes having an acidic group have the effect of enhancing the adsorptive power to the semiconductor electrode and improving the durability. Furthermore, there is an effect of expanding the absorption range.

R ³⁴ or R ^{34 ′} is preferably an oxygen atom. Thereby, the effect of improving the maximum molar extinction coefficient can be produced.

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

In the dye of the present invention represented by the general formula (1), the maximum absorption wavelength in a tetrahydrofuran: ethanol = 1: 1 solution is preferably in the range of 500 to 1300 nm, more preferably in the range of 600 to 1100 nm.
Although the preferable specific example of the pigment | dye represented by General formula (1) of this invention below is shown, this invention is not limited to this. Among the following dyes, for example, A-1 is in the skeleton A, each symbol represents a row of “1” in Table 1 and “1” in Table 2, and B-1 is in the skeleton B. Each symbol represents a row of “1” in Table 1 and “1” in Table 2. Tables 1 and 2 show A-1 to F-23.

Like Table 1 and Table 2, Tables 3 and 4 show G-24 to H-35.
The following skeletons G and H and G-24 to H-35 are reference examples.

Here, the following A-37, A-43, A-44, A-47, and A-50 to A-52 are reference examples.

Synthesis of a dye comprising a compound represented by the general formula (1) is described in Ukrainski Kimicheskii Zhurnal Vol. 40, No. 3, pages 253-258, Dies and Pigments, Vol. This can be done with reference to the description.
For example, the exemplified dye A-1 can be obtained by the following scheme. Other dyes can be obtained in the same manner.

(A2) Dye having a structure represented by the general formula (6) The photoelectric conversion element and the photoelectrochemical cell of the present invention include a dye composed of a compound represented by the following general formula (6).
Mz (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (6)
In the dye comprising the compound represented by the general formula (6), the ligand LL ¹ and / or the ligand LL ² and optionally a specific functional group X are coordinated to the metal atom, When necessary, it is kept electrically neutral by CI.
(A2-1) Metal atom Mz
Mz represents a metal atom. Mz is preferably a metal capable of tetracoordinate or hexacoordinate, and more preferably Ru, Fe, Os, Cu, W, Cr, Mo, Ni, Pd, Pt, Co, Ir, Rh, Re, Mn Or it is Zn. Particularly preferred is Ru, Os, Zn or Cu, and most preferred is Ru.

(A2-2) Ligand LL ¹
The ligand LL ¹ is a bidentate or tridentate ligand represented by a bidentate or tridentate ligand represented by the following general formula (7), preferably a bidentate ligand. is there. M1 representing the number of the ligand LL ¹ is an integer of 0 to 3, preferably 1 to 3, and more preferably 1. When m1 is 2 or more, LL ¹ may be the same or different. However, the m1, at least one of m2 representing the number of ligands LL ² below is an integer of 1 or more. Thus the metal atom, the ligand LL ¹ and / or ligand LL ² is coordinated.
R ⁵¹ and R ⁵² in the general formula (3) each independently represent an acidic group, for example, a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (preferably a hydroxamic acid group having 1 to 20 carbon atoms, for example, , —CONHOH, —CONCH ₃ OH, etc.), phosphoryl groups (eg —OP (O) (OH) ₂ etc.) and phosphonyl groups (eg —P (O) (OH) ₂ etc.) and salts thereof. Preferably they are a carboxyl group, a phosphonyl group, and these salts, More preferably, a carboxyl group or its salt is mentioned. R ⁵¹ and R ⁵² may be substituted on any carbon atom on the pyridine ring.

In the formula, R ⁵³ and R ⁵⁴ each independently represent a substituent, preferably an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1 -Ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably alkenyl groups having 2 to 20 carbon atoms such as vinyl, allyl, oleyl etc.), alkynyl groups (preferably carbon atoms) C2-C20 alkynyl groups such as ethynyl, butadiynyl, phenylethynyl, etc., cycloalkyl groups (preferably C3-C20 cycloalkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.) ), An aryl group (preferably an ant having 6 to 26 carbon atoms) Group such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl and the like, a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy, etc.) An aryloxy group (preferably an aryloxy group having 6 to 26 carbon atoms such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), an alkoxycarbonyl group (preferably having 2 to 2 carbon atoms) 20 alkoxycarbonyl groups such as ethoxycarbonyl, 2 Ethylhexyloxycarbonyl, etc.), amino group (preferably an amino group having 0-20 carbon atoms, such as amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), sulfonamide group (Preferably a sulfonamide group having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc.), an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, for example, acetyl Oxy, benzoyloxy and the like), a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), an acylamino group (preferably having 1 to 20 carbon atoms). An acylamino group such as acetylamino, benzoylamino, etc.), A cyano group or a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group An amino group, an acylamino group, a cyano group or a halogen atom, particularly preferably an alkyl group, an alkenyl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a cyano group.
When the ligand LL ¹ contains an alkyl group, an alkenyl group or the like, these may be linear or branched, and may be substituted or unsubstituted. Further, when the ligand LL ¹ contains an aryl group, a heterocyclic group or the like, they may be monocyclic or condensed and may be substituted or unsubstituted.

In the general formula (7), R ⁵⁵ and R ⁵⁶ are each independently an aromatic group (preferably an aromatic group having 6 to 30 carbon atoms such as phenyl, substituted phenyl, naphthyl, substituted naphthyl, etc.) or a heterocyclic ring Group (preferably a heterocyclic group having 1 to 30 carbon atoms, such as 2-thienyl, 2-pyrrolyl, 2-imidazolyl, 1-imidazolyl, 4-pyridyl, 3-indolyl), preferably 1 to 3 A heterocyclic group having an electron donating group, more preferably thienyl. The electron donating group is an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, an acylamino group (preferred examples are the same as those for R ⁵³ and R ⁵⁴ ) or a hydroxyl group. And more preferably an alkyl group, an alkoxy group, an amino group or a hydroxyl group, and particularly preferably an alkyl group. R ⁵⁵ and R ⁵⁶ may be the same or different, but are preferably the same.

R ⁵⁵ and R ⁵⁶ may be directly bonded to the benzene ring. R ⁵⁵ and R ⁵⁶ may be bonded to the benzene ring via L ¹ and / or L ² .
Here, L ¹ and L ² each independently represent a conjugated chain composed of an ethenylene group and / or an ethynylene group. The ethenylene group or ethynylene group may be unsubstituted or substituted. When the ethenylene group has a substituent, the substituent is preferably an alkyl group, and more preferably methyl. L ¹ and L ² are each independently preferably a conjugated chain having 2 to 6 carbon atoms, more preferably ethenylene, butadienylene, ethynylene, butadienylene, methylethenylene or dimethylethenylene, particularly ethenylene or butadienylene. Preferably, ethenylene is most preferred. L ¹ and L ² may be the same or different, but are preferably the same. When the conjugated chain contains a carbon-carbon double bond, each double bond may be a trans isomer, a cis isomer, or a mixture thereof.

d3 is 0 or 1, and a1 and a2 each independently represent an integer of 0 to 3. a1 is may be the R ⁵¹ when two or more be the same or different, R ⁵² when a2 is 2 or more may be the same or different. a1 is preferably 0 or 1, and a2 is preferably an integer of 0 to 2. In particular, when n is 0, a2 is preferably 1 or 2, and when n is 1, a2 is preferably 0 or 1. The sum of a1 and a2 is preferably an integer of 0-2.

b1 and b2 each independently represent an integer of 0 to 3, preferably an integer of 0 to 2. When b1 is 2 or more, R ⁵³ may be the same or different and may be connected to each other to form a ring. When b2 is 2 or more, R ⁵⁴ may be the same or different, and may be connected to each other to form a ring. When both b1 and b2 are 1 or more, R ⁵³ and R ⁵⁴ may be connected to form a ring. Preferable examples of the ring to be formed include a benzene ring, a pyridine ring, a thiophene ring, a pyrrole ring, a cyclohexane ring, a cyclopentane ring and the like.
When the sum of a1 and a2 is 1 or more and the ligand LL ¹ has at least one acidic group, m1 in the general formula (8) is preferably 2 or 3, and preferably 2. Is more preferable.

一般式（８）中、Ｚａ、Ｚｂ及びＺｃはそれぞれ独立に、５員環又は６員環を形成しうる非金属原子群を表す。形成される５員環又は６員環は置換されていても無置換でもよく、単環でも縮環していてもよい。Ｚａ、Ｚｂ及びＺｃは炭素原子、水素原子、窒素原子、酸素原子、硫黄原子、リン原子及び／又はハロゲン原子で構成されることが好ましく、芳香族環を形成するのが好ましい。５員環の場合はイミダゾール環、オキサゾール環、チアゾール環又はトリアゾール環を形成するのが好ましく、６員環の場合はピリジン環、ピリミジン環、ピリダジン環又はピラジン環を形成するのが好ましい。なかでもイミダゾール環又はピリジン環がより好ましい。
一般式（８）中、ｃは０または１を表す。ｃは０であるのが好ましく、ＬＬ^２は２座配位子であるのが好ましい。 (A2-3) Ligand LL ²
In the general formula (6), LL ² represents a bidentate or tridentate ligand. _{M 2} representing the number of ligands LL ² is an integer of 0 to 2, is preferably 0 or 1. When m ₂ is 2, LL ² may be the same or different. However, at least one is an integer equal to or greater than 1 among m ₂ and m ₁ representing the number of the ligand LL ¹ described above.
Ligand LL ² is a bidentate or tridentate ligand represented by the following general formula (8).

In General Formula (8), Za, Zb, and Zc each independently represent a nonmetallic atom group that can form a 5-membered ring or a 6-membered ring. The formed 5-membered or 6-membered ring may be substituted or unsubstituted, and may be monocyclic or condensed. Za, Zb and Zc are preferably composed of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom and / or a halogen atom, and preferably form an aromatic ring. In the case of a 5-membered ring, an imidazole ring, an oxazole ring, a thiazole ring or a triazole ring is preferably formed. In the case of a 6-membered ring, a pyridine ring, a pyrimidine ring, a pyridazine ring or a pyrazine ring is preferably formed. Of these, an imidazole ring or a pyridine ring is more preferable.
In general formula (8), c represents 0 or 1. c is preferably 0, and LL ² is preferably a bidentate ligand.

Ligand LL ² is preferably represented by any of the following general formula (9-1) - (9-8), the formula (9-1), (9-2), (9-4 ) Or (9-6), more preferably represented by formula (9-1) or (9-2), and represented by formula (9-1). Is most preferred.

In general formulas (9-1) to (9-8), R ^{101 to} R ¹⁰⁸ each independently represents an acidic group or a salt thereof. R ^{101 to} R ¹⁰⁸ are, for example, a carboxyl group, a sulfonic acid group, a hydroxyl group, a hydroxamic acid group (preferably a hydroxamic acid group having 1 to 20 carbon atoms, such as —CONHOH, —CONCH ₃ OH, etc.), a phosphoryl group ( For example, —OP (O) (OH) ₂ etc.) or a phosphonyl group (eg —P (O) (OH) ₂ etc.) or a salt thereof is represented. R ^{101 to} R ¹⁰⁸ are preferably a carboxyl group, a phosphoryl group, a phosphonyl group, or a salt thereof, more preferably a carboxyl group, a phosphonyl group, or a salt thereof, and more preferably a carboxyl group or a salt thereof.

In general formulas (9-1) to (9-8), R ^{109 to} R ¹¹⁶ each independently represent a substituent, preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, or an alkoxy group. , Aryloxy group, alkoxycarbonyl group, amino group, acyl group, sulfonamido group, acyloxy group, carbamoyl group, acylamino group, cyano group or halogen atom (the above preferred examples are R ¹¹ and R ¹² in formula (3)) More preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a halogen atom, particularly preferably an alkyl group or an alkenyl group. , Alkoxy group, alkoxycarbonyl group, amino group or acylamino group A.

In formulas (9-1) to (9-8), R ^{117 to} R ¹²¹ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. Of these, an aliphatic group and an aromatic group are preferable. More preferably, it is an aliphatic group having a carboxyl group. When the ligand LL ² contains an alkyl group, an alkenyl group or the like, they may be linear or branched and may be unsubstituted substituted. Further, LL ² is an aryl group, when containing heterocyclic group, they may be a condensed ring may be monocyclic or unsubstituted substituted.

In General Formulas (9-1) to (9-8), R ^{101 to} R ¹¹⁶ may be bonded to any position on the ring. E1 to e6 each independently represents an integer of 0 to 4, preferably an integer of 0 to 2. e7 and e8 each independently represents an integer of 0 to 4, preferably an integer of 0 to 3. e9 to e12 and e15 each independently represents an integer of 0 to 6, and e13, e14 and e16 each independently represents an integer of 0 to 4. e9 to e16 are each independently preferably an integer of 0 to 3.

When e1 to e8 is 2 or more, R ^{101 to} R ¹⁰⁸ may be the same or different, and when e9 to e16 is 2 or more, R ^{109 to} R ¹¹⁶ may be the same or different and are connected to each other. To form a ring.

(A2-4) Ligand X
In general formula (6), X represents a monodentate or bidentate ligand. M3 representing the number of ligands X represents an integer of 0 to 3, and m3 is preferably 1 or 2. When X is a monodentate ligand, m3 is preferably 2. When X is a bidentate ligand, m3 is preferably 1. When m3 is 2 or more, Xs may be the same or different, and Xs may be linked together.

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

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

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

(A2-5) Counter ion CI
CI in the general formula (6) represents a counter ion when a counter ion is necessary to neutralize the charge. In general, whether a dye is a cation or an anion or has a net ionic charge depends on the metal, ligand and substituent in the dye.
The dye of the general formula (6) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the charge of the whole dye of the general formula (6) is electrically neutralized by CI.

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

(A2-6) Bonding Group The dye having the structure represented by the general formula (6) 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. Carboxyl group, sulfonic acid group, hydroxyl group, hydroxamic acid group (for example, —CONHOH), phosphoryl group (for example, —OP (O) (OH) _2, etc.), phosphonyl group (for example, —P (O) (OH) _2, etc.) It is preferable that the dye has an acidic group (substituent having a dissociable proton).

  Although the specific example of the pigment | dye which has a structure represented by General formula (6) used by this invention is shown below, this invention is not limited to these. In addition, when the pigment | dye in the following specific example contains the ligand which has a proton dissociable group, this ligand may dissociate as needed and may discharge | release a proton.

The dye represented by the general formula (6) of the present invention can be synthesized with reference to JP-A No. 2001-291534 and the methods cited in the publication.
The dye composed of the compound represented by the general formula (6) 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 a range.
In the photoelectric conversion element and the photoelectrochemical cell of the present invention, a wide range of use is made by using a dye composed of at least the compound represented by the general formula (1) and a dye composed of the compound represented by the general formula (6). By using light of a wavelength, high conversion efficiency can be ensured.

  The blending ratio of the dye consisting of the compound represented by the general formula (6) and the dye consisting of the compound represented by the general formula (1) is as follows. S = 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.

(B) Charge Transfer Body Layer In a preferred embodiment of the photoelectric conversion element of the present invention as shown in FIG. 1, a layer made of an electrolyte composition can be applied to the charge transfer body layer 3 used in the photoelectric conversion element. As the redox pair, for example, a combination of iodine and iodide (eg, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.), alkyl viologen (eg, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoro) Borate) and its reduced form, a combination of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and its oxidized form, a combination of divalent and trivalent iron complexes (for example, red blood salt and yellow blood salt) Etc. Of these, a combination of iodine and iodide is preferred.
The cation of the iodine salt is preferably a 5-membered or 6-membered nitrogen-containing aromatic cation. In particular, when either or one of the compound represented by the general formula (1) and the compound represented by the general formula (2) is not an iodine salt, WO95 / 18456, JP-A-8-259543, electrochemistry, Vol. 65, No. 11, p. 923 (1997) and the like, and iodine salts such as pyridinium salts, imidazolium salts and triazolium salts are preferably used in combination.
The electrolyte composition used for the photoelectric conversion element 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 of the present invention may contain a solvent. The content of the solvent in the electrolyte composition is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less based on the entire composition.
As the solvent, a solvent having a low viscosity and high ion mobility, a high dielectric constant and capable of increasing the effective carrier concentration, or both is preferable because it can exhibit excellent ion conductivity. As such a solvent, carbonate compounds (ethylene carbonate, propylene carbonate, etc.), heterocyclic compounds (3-methyl-2-oxazolidinone, etc.), ether compounds (dioxane, diethyl ether, etc.), chain ethers (ethylene glycol dialkyl ether, Propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.), Polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol , Polypropylene glycol, glycerol, etc.), nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, biscyanoethyl ether, etc.), esters (carboxylic esters, phosphate esters, phosphonate esters, etc.) ), Aprotic polar solvent (dimethyl sulfoxide (DMSO), sulfolane, etc.), water, hydrous electrolyte described in JP-A No. 2002-110262, JP-A No. 2000-36332, JP-A No. 2000-243134, and republication Examples include electrolyte solvents described in WO / 00-54361. These solvents may be used as a mixture of two or more.

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

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

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

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

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

  The gel electrolyte may be formed by polymerization of a mixture containing a monofunctional monomer in addition to the above polyfunctional monomers. Monofunctional monomers include acrylic acid or α-alkyl acrylic acid (acrylic acid, methacrylic acid, itaconic acid, etc.) or esters or amides thereof (methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n- Butyl acrylate, i-butyl acrylate, t-butyl acrylate, n-pentyl acrylate, 3-pentyl acrylate, t-pentyl acrylate, n-hexyl acrylate, 2,2-dimethylbutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate 4-methyl-2-propylpentyl acrylate, cetyl acrylate, n-octadecyl acrylate, cyclohexyl acrylate, cyclopentyl acrylate, benzyl acrylate Hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxyethoxyethyl acrylate, phenoxyethyl acrylate, 3-methoxybutyl acrylate, ethyl carbitol acrylate, 2-methyl- 2-nitropropyl acrylate, 2,2,2-trifluoroethyl acrylate, octafluoropentyl acrylate, heptadecafluorodecyl acrylate, methyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, t-pentyl methacrylate , N-octadecyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate, 2-hydroxypropy Methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-methoxyethoxyethyl methacrylate, dimethylaminoethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, heptadeca Fluorodecyl methacrylate, ethylene glycol ethyl carbonate methacrylate, 2-isobornyl methacrylate, 2-norbornylmethyl methacrylate, 5-norbornen-2-ylmethyl methacrylate, 3-methyl-2-norbornylmethyl methacrylate, acrylamide, N- i-propylacrylamide, Nn-butylacrylamide, Nt-butylacrylamide, N, N-dimethyl Acrylamide, N-methylolacrylamide, diacetoneacrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidopropyltrimethylammonium chloride, methacrylamide, N-methylmethacrylamide, N-methylolmethacrylamide, etc.), vinyl esters (acetic acid) Vinyl), maleic acid or fumaric acid or esters derived therefrom (dimethyl maleate, dibutyl maleate, diethyl fumarate, etc.), sodium salt of p-styrenesulfonic acid, acrylonitrile, methacrylonitrile, dienes ( Butadiene, cyclopentadiene, isoprene, etc.), aromatic vinyl compounds (styrene, p-chlorostyrene, t-butylstyrene, α-methylstyrene, sodium styrene sulfonate) N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, vinyl sulfonic acid, sodium vinyl sulfonate, sodium allyl sulfonate, sodium methacryl sulfonate Vinylidene fluoride, vinylidene chloride, vinyl alkyl ethers (such as methyl vinyl ether), ethylene, propylene, butene, isobutene, N-phenylmaleimide and the like can be used.

The blending amount of the polyfunctional monomer is preferably 0.5 to 70% by mass and more preferably 1.0 to 50% by mass with respect to the whole monomer. The above-mentioned monomers are the same as those described in Takayuki Otsu and Masaaki Kinoshita “Experimental Methods for Polymer Synthesis” (Chemistry Dojin) and Takayuki Otsu “Lecture Polymerization Reaction Theory 1 Radical Polymerization (I)” (Chemical Doujinshi). Polymerization can be performed by radical polymerization which is a polymer synthesis method. The monomer for gel electrolyte used in the present invention can be radically polymerized by heating, light or electron beam, or electrochemically, and is particularly preferably radically polymerized by heating. In this case, preferably used polymerization initiators are 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropyl). Pionate), azo initiators such as dimethyl 2,2′-azobisisobutyrate, peroxide initiators such as lauryl peroxide, benzoyl peroxide, and t-butyl peroctoate. The preferable addition amount of a polymerization initiator is 0.01-20 mass% with respect to the monomer total amount, More preferably, it is 0.1-10 mass%.
The weight composition range of the monomer in the gel electrolyte is preferably 0.5 to 70% by mass. More preferably, it is 1.0-50 mass%. When the electrolyte composition is gelled by a polymer crosslinking reaction, it is preferable to add a polymer having a reactive group capable of crosslinking to the composition and a crosslinking agent. Preferred reactive groups are nitrogen-containing heterocycles such as pyridine ring, imidazole ring, thiazole ring, oxazole ring, triazole ring, morpholine ring, piperidine ring, piperazine ring, and the preferred crosslinking agent is a functional group capable of nucleophilic attack by the nitrogen atom. Is a compound (electrophile) having two or more of, for example, a bifunctional or higher functional alkyl halide, halogenated aralkyl, sulfonic acid ester, acid anhydride, acid chloride, isocyanate and the like.

The electrolyte composition can be used in the present invention, metal iodides (LiI, NaI, KI, CsI , CaI 2 , etc.), a metal bromide (LiBr, NaBr, KBr, CsBr , CaBr 2 , etc.), quaternary ammonium bromine Salt (tetraalkylammonium bromide, pyridinium bromide, etc.), metal complex (ferrocyanate-ferricyanate, ferrocene-ferricinium ion, etc.), sulfur compounds (sodium polysulfide, alkylthiol-alkyl disulfide, etc.), viologen dye Hydroquinone-quinone and the like may be added. These may be used as a mixture.

  In addition, electrolyte compositions that can be used in the present invention include J.I. Am. Ceram. Soc., 80 (12), p. Basic compounds such as t-butylpyridine described in 3157-3171 (1997), 2-picoline, and 2,6-lutidine may be added. A preferable concentration range in the case of adding a basic compound is 0.05 to 2M.

In addition, as the charge transfer layer 3 in the photoelectric conversion element of the present invention, a charge transport layer containing a hole conductor substance may be used. As the hole conductor material, 9,9′-spirobifluorene derivative or the like can be used.
Moreover, as a structure of an electrochemical element, a conductive support (electrode layer), a photoelectric conversion layer (photosensitive layer and charge transfer layer), a hole transport layer, a conductive layer, and a counter electrode layer can be sequentially laminated.

  A hole transport material that functions as a p-type semiconductor can be used as 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, the organic polysilane is a polymer having a main chain Si chain unlike the conventional carbon-based polymer. Since σ electrons delocalized along the main chain Si contribute to photoconduction, it has high hole mobility (see Phys. Rev. B, 35, p. 2818 (1987), etc.), which is preferable.

The conductive layer that can be provided in the photoelectric conversion element of the present invention is not particularly limited as long as it has good conductivity. For example, an inorganic conductive material, an organic conductive material, a conductive polymer, an intermolecular charge transfer complex, and the like can be used. Can be mentioned. Of these, intermolecular charge transfer complexes are preferred. Here, the intermolecular charge transfer complex is formed from a donor material and an acceptor material. Moreover, an organic donor and an organic acceptor can be used preferably.
The donor material is preferably a material rich in electrons in the molecular structure. For example, organic donor materials include those having a substituted or unsubstituted amine group, hydroxyl group, ether group, selenium or sulfur atom in the π-electron system of the molecule, specifically, phenylamine-based, triphenylmethane , Carbazole, phenol, and tetrathiafulvalene materials.
As the acceptor material, those lacking electrons in the molecular structure are preferable. For example, organic acceptor materials include fullerenes, those having a substituent such as nitro group, cyano group, carboxyl group or halogen group in the π-electron system of the molecule, specifically PCBM, benzoquinone, naphthoquinone, etc. Quinone, fluoroenone, chloranil, bromanyl, tetracyanoquinodimethane, tetracyanoethylene and the like.
In addition, the thickness of the conductive layer is not particularly limited, but is preferably an extent that can completely fill the porous layer.

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

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

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

Preferred conductive films include metals (eg, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.) ).
The thickness of the conductive film layer is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm.

The conductive support 1 preferably has a lower surface resistance. The range of the surface resistance is preferably 50 Ω / cm ² or less, more preferably 10 Ω / cm ² or less. Although there is no restriction | limiting in particular in this lower limit, Usually, it is about 0.1 ohm / cm < ² >.

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

(D) Semiconductor Fine Particles As shown in FIG. 1, in a preferred embodiment of the photoelectric conversion element of the present invention, a photosensitive layer 2 in which a dye 21 is adsorbed on porous semiconductor fine particles 22 is formed on a conductive support 1. Is formed. As will be described later, for example, the photoreceptor layer 2 can be produced by immersing the dispersion of semiconductor fine particles in the dye solution of the present invention after coating and drying the conductive support.

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

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

For the purpose of keeping the viscosity of the semiconductor fine particle dispersion high, it is preferable that the average particle size of the primary particles is 2 nm to 50 nm, and the average primary particle size is 2 nm to 30 nm. More preferably, it is a fine particle. Two or more kinds of fine particles having different particle size distributions may be mixed. In this case, the average size of the small particles is preferably 5 nm or less. In addition, for the purpose of scattering incident light and improving the light capture rate, large particles having an average particle size exceeding 50 nm can be added to the ultrafine particles at a low content, or another layer can be applied. In this case, the content of the large particles is preferably 50% or less, more preferably 20% or less of the mass of particles having an average particle size of 50 nm or less. The average particle size of the large particles added and mixed for the above purpose is preferably 100 nm or more, and more preferably 250 nm or more.
By using large particles for light scattering, the haze ratio is preferably 60% or more. The haze ratio is expressed by (diffuse transmittance) / (total light transmittance).

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

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

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

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

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

(E) Semiconductor fine particle dispersion In the present invention, a semiconductor fine particle dispersion in which the solid content other than the semiconductor fine particles is 10% by mass or less of the entire semiconductor fine particle dispersion is applied to the conductive support. The porous semiconductor fine particle coating layer (photoreceptor layer) can be obtained by heating to.
In addition to the sol-gel method described above, a method of preparing a semiconductor fine particle dispersion is a method of depositing fine particles in a solvent and using them as they are when synthesizing a semiconductor. Ultrafine particles are irradiated with ultrasonic waves. Or a method of mechanically pulverizing and grinding using a mill or a mortar. As the dispersion solvent, water and / or various organic solvents can be used. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, citronellol and terpineol, ketones such as acetone, esters such as ethyl acetate, dichloromethane, acetonitrile and the like.

At the time of dispersion, a small amount of, for example, a polymer such as polyethylene glycol, hydroxyethyl cellulose, carboxymethyl cellulose, a surfactant, an acid, or a chelating agent may be used as a dispersion aid. However, most of these dispersing aids are preferably removed by a filtration method, a method using a separation membrane, a centrifugal method or the like before the step of forming a film on a conductive support. In the semiconductor fine particle dispersion, the solid content other than the semiconductor fine particles can be 10% by mass or less of the total dispersion. This concentration is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. More preferably, it is 0.5% or less, and particularly preferably 0.2%. That is, in the semiconductor fine particle dispersion, the solid content other than the solvent and the semiconductor fine particles can be 10% by mass or less of the entire semiconductor fine dispersion. It is preferable to consist essentially of semiconductor fine particles and a dispersion solvent.
If the viscosity of the semiconductor fine particle dispersion is too high, the dispersion will aggregate and cannot be formed into a film. Conversely, if the viscosity of the semiconductor fine particle dispersion is too low, the liquid will flow and cannot be formed into a film. is there. Therefore, the viscosity of the dispersion is preferably 10 to 300 N · s / m ² at 25 ° C. More preferably, it is 50 to 200 N · s / m ² at 25 ° C.

  As a method for applying the semiconductor fine particle dispersion, a roller method, a dip method, or the like can be used as an application method. Moreover, an air knife method, a blade method, etc. can be used as a metering method. Further, the application system method and the metering system method can be made the same part. The wire bar method disclosed in Japanese Patent Publication No. 58-4589, the slide hopper method described in US Pat. No. 2,681,294, etc., the extrusion The method and the curtain method are preferable. It is also preferable to apply by a spin method or a spray method using a general-purpose machine. As the wet printing method, intaglio, rubber plate, screen printing and the like are preferred, including the three major printing methods of letterpress, offset and gravure. From these, a preferred film forming method is selected according to the liquid viscosity and the wet thickness. Moreover, since the semiconductor fine particle dispersion has a high viscosity and has a viscous property, it may have a strong cohesive force and may not be well adapted to the support during coating. In such a case, by performing cleaning and hydrophilization of the surface by UV ozone treatment, the binding force between the applied semiconductor fine particle dispersion and the surface of the conductive support increases, and the semiconductor fine particle dispersion can be easily applied.

The preferred thickness of the entire semiconductor fine particle layer is 0.1 to 100 μm. The thickness of the semiconductor fine particle layer is further preferably 1 to 30 μm, and more preferably 2 to 25 μm. The amount of the semiconductor fine particles supported per 1 m ² of the support is preferably 0.5 g to 400 g, more preferably 5 to 100 g.

The applied semiconductor fine particle layer is subjected to heat treatment in order to enhance the electronic contact between the semiconductor fine particles and to improve the adhesion to the support and to dry the applied semiconductor fine particle dispersion. . By this heat treatment, a porous semiconductor fine particle layer can be formed. In addition, the semiconductor fine particle layer may be formed by a known method as appropriate according to the characteristics and application of the member. For example, the materials, preparation methods, and manufacturing methods described in Japanese Patent Application Laid-Open No. 2001-291534 can be referred to, and are cited in this specification.
In addition to heat treatment, light energy can also be used. For example, when titanium oxide is used as the semiconductor fine particles, the surface may be activated by applying light absorbed by the semiconductor fine particles such as ultraviolet light, or only the surface of the semiconductor fine particles may be activated by laser light or the like. Can do. By irradiating the semiconductor fine particles with light absorbed by the fine particles, the impurities adsorbed on the particle surface are decomposed by the activation of the particle surface, and can be brought into a preferable state for the above purpose. When heat treatment and ultraviolet light are combined, it is preferable that heating be performed at 100 ° C. or higher and 250 ° C. or lower, or preferably 100 ° C. or higher and 150 ° C. or lower, while irradiating the semiconductor fine particles with light absorbed by the fine particles. Thus, by photoexciting the semiconductor fine particles, impurities mixed in the fine particle layer can be washed by photolysis, and physical bonding between the fine particles can be strengthened.

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

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

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

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

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

In general, as the thickness of the semiconductor fine particle layer increases, the amount of dye that can be carried per unit area increases, so that the light absorption efficiency increases. However, since the diffusion distance of the generated electrons increases, the loss due to charge recombination also increases. The preferred thickness of the semiconductor fine particle layer varies depending on the use of the device, but is typically 0.1 to 100 μm. When using as a photoelectrochemical cell, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 3-30 micrometers. The semiconductor fine particles may be heated at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours in order to adhere the particles to each other after being applied to the support. When glass is used as the support, the film forming temperature is preferably 400 to 600 ° C.
When a polymer material is used as the support, it is preferably heated after film formation at 250 ° C. or lower. In this case, the film forming method may be any one of (1) a wet method, (2) a dry method, and (3) an electrophoresis method (including an electrodeposition method), preferably (1) a wet method, or ( 2) A dry method, more preferably (1) a wet method.
The coating amount of the semiconductor fine particles per 1 m ² of the support is preferably 0.5 to 500 g, more preferably 5 to 100 g.

  In order to adsorb the dye to the semiconductor fine particles, it is preferable to immerse the well-dried semiconductor fine particles in a dye adsorbing dye solution comprising the solution and the dye of 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 is a solution that can dissolve the dye of the present invention. For example, ethanol, methanol, isopropanol, toluene, t-butanol, acetonitrile, acetone, n-butanol and the like can be used. Among these, ethanol and toluene can be preferably used.

  The dye solution for dye adsorption comprising the solution and the dye of the present invention may be heated to 50 ° C. to 100 ° C. as necessary. The adsorption of the dye may be performed before or after application of the semiconductor fine particles. Further, the semiconductor fine particles and the dye may be applied and adsorbed simultaneously. Unadsorbed dye is removed by washing. When baking a coating film, it is preferable to adsorb | suck a pigment | dye after baking. It is particularly preferable that the dye is quickly adsorbed after the baking and before water adsorbs on the surface of the coating film. One type of dye may be adsorbed or a mixture of several types may be used. When mixing, 2 or more types of the pigment | dye of this invention may be mixed, and the complex pigment | dye and the pigment | dye of this invention may be mixed within the range which does not impair the meaning of this invention. The dye to be mixed is selected so as to make the wavelength range of photoelectric conversion as wide as possible. When mixing the dyes, it is necessary to prepare a dye solution for dye adsorption so that all the dyes are dissolved.

The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and particularly preferably 0.1 to 10 mmol per 1 m ² of the support. In this case, it is preferable that the usage-amount of the metal complex pigment | dye represented by General formula (1) of this invention shall be 5 mol% or more. Furthermore, when using together the pigment | dye represented by General formula (2), it is preferable that the usage-amount of the pigment | dye represented by General formula (2) shall be 80 mol% or more.
Further, the adsorption amount of the dye to the semiconductor fine particles is preferably 0.001 to 1 mmol, more preferably 0.1 to 0.5 mmol, with respect to 1 g of the semiconductor fine particles.
By using such a dye amount, a sensitizing effect in a semiconductor can be sufficiently obtained. On the other hand, when the amount of the dye is small, the sensitizing effect is insufficient, and when the amount of the dye is too large, the dye not attached to the semiconductor floats and causes the sensitizing effect to be reduced.

  Further, a colorless compound may be co-adsorbed for the purpose of reducing the interaction between dyes such as association. Examples of the hydrophobic compound to be co-adsorbed include steroid compounds having a carboxyl group (for example, cholic acid and pivaloyl acid).

  After adsorbing the dye, the surface of the semiconductor fine particles may be treated with amines. Preferred amines include 4-tert-butyl pyridine, polyvinyl pyridine and the like. These may be used as they are in the case of a liquid, or may be used by dissolving in an organic solvent.

(F) Counter electrode The counter electrode (counter electrode) serves as the positive electrode of the photoelectrochemical cell. The counter electrode is usually synonymous with the conductive support described above, but the counter electrode is not necessarily required in a configuration in which the strength is sufficiently maintained. However, it is advantageous in terms of hermeticity to have a counter electrode.

Examples of the counter electrode material include platinum, carbon, and conductive polymer. Preferable examples include platinum, carbon, and conductive polymer.
As the structure of the counter electrode, a structure having a high current collecting effect is preferable. Preferable examples include JP-A-10-505192.
The light receiving electrode may be a composite electrode such as titanium oxide and tin oxide (TiO ₂ / SnO ₂ ). Examples of the titania mixed electrode include those described in JP-A No. 2000-11393. Examples of mixed electrodes other than titania include those described in JP-A Nos. 2001-185243 and 2003-282164.

(G) Light receiving electrode The light receiving electrode 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 light receiving electrode layer may be provided. Preferably, the thing of Unexamined-Japanese-Patent No. 2002-93476 is mentioned.

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

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

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

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

1. Preparation of Dye Hereinafter, the method for preparing the dye of the present invention will be described in detail with reference to Examples, but the starting material, dye intermediate and preparation route are not limited thereto.

(1) Preparation Example 1
(Preparation of Exemplified Compound A-1)
Dye A-1 was prepared according to the scheme shown below.

  0.56 g of the compound 1-1 g, 0.85 g of the compound 1-2, and 1 mL of triethylamine were mixed in a mixed solvent of 5 mL of 1-butanol and 15 mL of toluene, and the mixture was heated and stirred at 120 ° C. for 4 hours. Thereafter, the reaction solution was concentrated, and the resulting residue was purified by column chromatography to obtain 0.24 g of compound 1-3.

0.24 g of compound 1-3 and 0.13 g of compound 1-4 were mixed in a mixed solvent of 5 mL of 1-butanol and 5 mL of toluene, and the mixture was heated and stirred at 100 ° C. for 2 hours. Thereafter, water and ethyl acetate were added to the reaction solution to perform extraction / separation, and the ethyl acetate layer was concentrated. The obtained residue was purified by column chromatography to obtain 0.15 g of A-1. When identification was performed by Millimas, the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1139.7195
Mass calculated value (m / z); (M + H) ⁺ : 1139.7181 (C ₇₃ H ₉₄ N ₄ O ₇ )

(2) Preparation Example 2
(Preparation of Exemplified Compound A-36)
Dye A-36 was prepared according to the scheme shown below.

(Preparation of compound 36-5)
Compound 36-4 (1.0 g) and t-butyl cyanoacetate (0.46 g) were dissolved in 10 mL of EtOH and cooled to an internal temperature of 4 ° C. 1 mL of 28% NaOMe in MeOH was added dropwise thereto, and water was added to the stirring word for 1 hour. The precipitated crystals were filtered to obtain Compound 36-5 (1.4 g).

(Preparation of Compound 36-6)
Compound 36-5 (0.27 g) and compound 1-2 (0.15 g) were stirred in a quinoline solution at 150 ° C. for 20 hours. After allowing to cool, dichloromethane and water were added, liquid separation was performed, and the organic phase was concentrated. This was purified by column chromatography to give compound 36-6 (0.25 g).

(Preparation of compound 36-7)
Compound 36-6 (0.23 g) and compound 1-2 (0.11 g) were stirred in a toluene / n-BuOH = 1/1 solution at 110 ° C. for 5 hours. After allowing to cool, dichloromethane and water were added, liquid separation was performed, and the organic phase was concentrated. This was purified by column chromatography to give compound 36-7 (0.26 g).

(Preparation of A-36)
36-7 (0.26 g) was dissolved in THF (10 mL). TFA (0.5 mL) was added thereto, and the mixture was stirred at room temperature for 3 hours, and then water was added to precipitate crystals. This was filtered to obtain A-36 (0.20 g).
Identification was performed by Millimas and the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1293.81
Mass calculated value (m / z); (M + H) ⁺ : 1293.81

(3) Preparation Example 3
(Preparation of dye C-18)
Dye C-18 was prepared according to the scheme shown below.

  0.83 g of the compound 2-1 and 0.82 g of the compound 2-2 and 1 mL of triethylamine were mixed in a mixed solvent of 7 mL of 1-butanol and 10 mL of toluene, and the mixture was heated and stirred at 120 ° C. for 4 hours. Thereafter, the reaction solution was concentrated, and the resulting residue was purified by column chromatography to obtain 0.23 g of compound 2-3.

0.23 g of compound 2-3 and 0.1 g of compound 1-4 were mixed in a mixed solvent of 5 mL of 1-butanol and 5 mL of toluene, and heated and stirred at 100 ° C. for 2 hours. Thereafter, water and ethyl acetate were added to the reaction solution to perform extraction / separation, and the ethyl acetate layer was concentrated. The obtained residue was purified by column chromatography to obtain 0.13 g of C-18. Identification was performed by Millimas and the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1523.0172
Mass calculated value (m / z); (M + H) ⁺ : 1523.0155 (C ₁₀₂ H ₁₃₂ N ₅ O ₆ )

(4) Preparation Example 4
(Preparation of dye E-15)
Compound E-15 was prepared according to the scheme shown below.

  0.72 g of compound 3-1, 1.0 g of compound 3-2, and 1 mL of triethylamine were mixed in a mixed solvent of 5 mL of 1-butanol and 15 mL of toluene, and the mixture was heated and stirred at 120 ° C. for 4 hours. Thereafter, the reaction solution was concentrated, and the resulting residue was purified by column chromatography to obtain 0.19 g of Compound 3-3.

0.19 g of compound 3-3 and 0.09 g of compound 1-4 were mixed in a mixed solvent of 5 mL of 1-butanol and 5 mL of toluene, and the mixture was heated and stirred at 100 ° C. for 2 hours. Thereafter, water and ethyl acetate were added to the reaction solution to perform extraction / separation, and the ethyl acetate layer was concentrated. The obtained residue was purified by column chromatography to obtain 0.12 g of E-15. When identification was performed by Millimas, the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1416.7579
Mass calculated value (m / z); (M + H) ⁺ : 1416.7520 (C ₉₀ H ₁₀₆ N ₅ O ₆ S ₂ )
By the same method, the dye of the present invention of the general formula (1) used in the experiment was prepared. The dye represented by the general formula (6) was prepared by referring to Japanese Patent Application Laid-Open No. 2001-291534 and the method cited in the publication.

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

[Experiment 1-2]
(Preparation of photoelectric conversion element)
The photoelectric conversion element shown in FIG. 1 was produced as follows.
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts.
Next, 32 g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) is mixed with 100 ml of a mixed solvent of water and acetonitrile having a volume ratio of 4: 1, and a rotating / revolving mixing conditioner is prepared. The resulting mixture was uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion. This dispersion was applied to a transparent conductive film and heated at 500 ° C. to produce a light receiving electrode.
Thereafter, similarly, a dispersion containing 40:60 (mass ratio) of silica particles and rutile-type titanium oxide is prepared, and this dispersion is applied to the light receiving electrode and heated at 500 ° C. to form an insulating porous material. Formed body. Next, a carbon electrode was formed as a counter electrode.
Next, the glass substrate on which the above-mentioned insulating porous body was formed was immersed in an ethanol solution (3 × 10 ⁻⁴ mol / L) of a sensitizing dye described in Table 6 below for 1 hour. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² . As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / L) and iodine (0.1 mol / L) was used.

(Measurement of IPCE (quantum yield))
IPCE at 400 to 850 nm of the produced photoelectric conversion element was measured with an IPCE measuring device manufactured by Pexel. The IPCE at 820 nm of each photoelectric conversion element is shown in Table 6 below.

(Measurement of photoelectric conversion efficiency)
Simulated sunlight containing no ultraviolet rays was generated by passing the light of a 500 W xenon lamp (manufactured by Ushio) through an AM1.5G filter (manufactured by Oriel) and a sharp cut filter (KenkoL-42, trade name). The intensity of this light was 89 mW / cm ² . The produced photoelectric conversion element was irradiated with this light, and the generated electricity was measured with a current-voltage measuring device (Caseley 238 type, trade name). The results of measuring the photoelectric conversion efficiency of the photoelectrochemical cell thus obtained are shown in Table 6 below. Photoelectric conversion efficiency of 3.5% or more is ◎, 2.5% or more and less than 3.5% ○, 2.0% or more and less than 2.5% △, less than 2.0% A thing was evaluated as x, and a photoelectric conversion efficiency of 2.5% or more was regarded as acceptable.

The following sensitizing dye S-1 was used as sample number 1-18.

As shown in Table 6, the electrochemical cell produced using the dye of the present invention has B-2, C-22, C-23, D-3, D-21, F- as dyes. When 1, F-6 , A- 36 was used, the photoelectric conversion efficiency showed a high value of 3.5% or more. Even when other dyes of the present invention were used, the photoelectric conversion efficiency was at a relatively high level of 2.5% or more and less than 3.5%.
On the other hand, the photoelectric conversion efficiency of the comparative example of sample number 1-18 was insufficient with less than 2.0%.

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

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

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

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

(4) Production of photoelectrochemical cell Next, a photoelectrochemical cell having the structure shown in FIG. 2 of Japanese Patent No. 4260494 was produced using the above three types of transparent electrode plates. The oxide semiconductor porous film 15 is formed by dispersing fine particles of titanium oxide having an average particle diameter of about 230 nm in 100 mL of acetonitrile to form a paste, applying the paste to a thickness of 15 μm on a transparent electrode by a bar coating method, and drying 450 The oxide semiconductor porous film 15 was loaded with the dyes listed in Table 2 by baking at 1 ° C. for 1 hour. The immersion conditions in the dye solution were the same as those in Experiment 1-2.
Further, a conductive substrate in which an ITO film and an FTO film were laminated on a glass plate was used for the counter electrode, and an electrolyte solution made of a non-aqueous solution of iodine / iodide was used for the electrolyte layer. The planar dimensions of the photoelectrochemical cell were 25 mm long and 25 mm wide.

(5) Evaluation of photoelectrochemical cell About this photoelectrochemical cell, artificial sunlight (AM1.5) was irradiated and the photoelectric conversion efficiency was calculated | required. The results are shown in Table 7. Photoelectric conversion efficiency of 3.5% or more is ◎, 2.5% or more and less than 3.5% ○, 2.0% or more and less than 2.5% △, less than 2.0% A thing was evaluated as x, and a photoelectric conversion efficiency of 2.5% or more was regarded as acceptable.
In the sample numbers 2-13 to 2-15 using the sensitizing dye S-1, the photoelectric conversion efficiency is low, whereas in the sample numbers 2-1 to 2-12 using the exemplary dyes of the present invention, the photoelectric conversion efficiency is High value was shown. In a photoelectrochemical cell using a laminate of an ITO film and an FTO film as a transparent electrode plate and using the dye of the present invention, the photoelectric film is particularly photoelectrical compared to the case where only the ITO film or only the FTO film is used. It was found that the conversion efficiency is high and the effect of the dye of the present invention is high.

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

(Test cell (i))
The surface of a heat-resistant glass plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was chemically cleaned and dried, then placed in a reactor and heated with a heater, and then the FTO (fluorine-doped dope) used in Experiment 2 above. The tin oxide film raw material compound solution was sprayed from a nozzle with a diameter of 0.3 mm at a pressure of 0.06 MPa and a distance to the glass plate of 400 mm for 25 minutes to prepare a glass substrate with an FTO film. On the surface, grooves having a depth of 5 μm were formed in a lattice circuit pattern by an etching method. After pattern formation by photolithography, etching was performed using hydrofluoric acid. A metal conductive layer (seed layer) was formed thereon by sputtering in order to enable plating formation, and a metal wiring layer 3 was further formed by additive plating. The metal wiring layer 3 was formed in a convex lens shape from the surface of the transparent substrate 2 to a height of 3 μm. The circuit width was 60 μm. From this, an FTO film having a thickness of 400 nm was formed as the shielding layer 5 by the SPD method to obtain an electrode substrate (i). The cross-sectional shape of the electrode substrate (i) was as shown in FIG. 2 in JP-A No. 2004-146425.
On the electrode substrate (i), a dispersion obtained by dispersing titanium oxide having an average particle diameter of 25 nm in 100 mL of acetonitrile was applied and dried, and heated and sintered at 450 ° C. for 1 hour. This was immersed in an ethanol solution of the dye shown in Table 3 to adsorb the dye. The immersion conditions were the same as in Example 1. It arrange | positioned facing a platinum sputter | spatter FTO board | substrate through a 50-micrometer-thick thermoplastic polyolefin resin sheet, the resin sheet part was heat-melted, and the bipolar plate was fixed.
A methoxyacetonitrile solution containing 0.5M iodide and 0.05M iodine as the main components was injected from the electrolyte solution inlet previously opened on the platinum sputter electrode side, and filled between the electrodes. It was. Further, the peripheral portion 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 portion to obtain a test cell (i). The photoelectric conversion characteristics of the test cell (i) were evaluated using pseudo sunlight of AM1.5. The results are shown in Table 8.

(Test cell (ii))
A glass substrate with an FTO film having a length of 100 mm and a width of 100 mm was prepared in the same manner as in the test cell (i). A metal wiring layer 3 (gold circuit) was formed on the FTO glass substrate by additive plating. The metal wiring layer 3 (gold circuit) was formed in a lattice shape on the substrate surface, and had a circuit width of 50 μm and a circuit thickness of 5 μm. On this surface, an FTO film having a thickness of 300 nm was formed as a shielding layer 5 by the SPD method to obtain a test cell (ii). When the cross section of the electrode substrate (ii) was confirmed using SEM-EDX, there was a sneaking in which seems to be caused by the skirting of the plating resist at the bottom of the wiring, and the shadow portion was not covered with FTO.
Using the electrode substrate (ii), a test cell (ii) was produced in the same manner as the test cell (i). The photoelectric conversion characteristics of the test cell (ii) were evaluated using pseudo sunlight of AM1.5, and the results are shown in Table 8. Photoelectric conversion efficiency of 3.5% or more is ◎, 2.5% or more and less than 3.5% ○, 2.0% or more and less than 2.5% △, less than 2.0% A thing was evaluated as x, and a photoelectric conversion efficiency of 2.5% or more was regarded as acceptable.

  From Table 8, when the pigment | dye of this invention was used, the conversion efficiency of the test cell (i) showed a high value with 3.5% or more. On the other hand, when the test cell (ii) was used, the photoelectric conversion efficiency was higher when the dye of the present invention was used as compared with the case where the dye of the comparative example was used. For this reason, it was found that the degree of freedom of test cell selection is increased by using the dye of the present invention.

[Experiment 4]
Photoelectrochemical cells (A) to (D) were prepared as shown below, and the photoelectric conversion efficiency of these test cells was evaluated.

(Photoelectrochemical cell (A))
(1) Preparation of coating liquid (A) for forming an oxide semiconductor film 5 g of titanium hydride is suspended in 1 liter of pure water, 400 g of a 5 mass% hydrogen peroxide solution is added over 30 minutes, and then 80 A solution of peroxotitanic acid was prepared by heating to ° C and dissolution. 90% by volume was taken from the total amount of this solution, adjusted to pH 9 by adding concentrated aqueous ammonia, placed in an autoclave, hydrothermally treated at 250 ° C. for 5 hours under saturated vapor pressure, and titania colloidal particles (A) Was prepared. The obtained titania colloidal particles were anatase type titanium oxide having high crystallinity by X-ray diffraction.
Next, the obtained titania colloidal particles (A) was concentrated to 10 wt%, the peroxotitanic acid solution were mixed, the titanium of the mixed solution TiO ₂ terms, TiO ₂ mass of 30 mass% Then, hydroxypropylcellulose was added as a film formation aid so that a coating solution for forming a semiconductor film was prepared.

(2) Production of oxide semiconductor film (A) Next, the coating solution was applied on a transparent glass substrate on which fluorine-doped tin oxide was formed as an electrode layer, dried naturally, and subsequently 6000 mJ using a low-pressure mercury lamp. The peroxoacid was decomposed by irradiating UV light of / cm ² to cure the coating film. The coating film was heated at 300 ° C. for 30 minutes to decompose and anneal the hydroxypropyl cellulose to form an oxide semiconductor film (A) on the glass substrate.

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

(4) Preparation of electrolyte solution Dissolve tetrapropylammonium iodide to a concentration of 0.46 mol / L and iodine to a concentration of 0.07 mol / L in a 1: 5 mixed solvent of acetonitrile and ethylene carbonate. Thus, an electrolyte solution was prepared.

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

(6) Evaluation of photoelectrochemical cell (A) The photoelectrochemical cell (A) was irradiated with light having an intensity of 100 W / m ² with a solar simulator to measure the photoelectric conversion efficiency. Indicated.

(Photoelectrochemical cell (B))
Oxide semiconductor film (A) except that after irradiation with ultraviolet light, peroxo acid was decomposed and the film was cured, Ar gas ion irradiation (Nisshin Electric Co., Ltd .: ion implantation apparatus, irradiation at 200 eV for 10 hours) was performed. ), An oxide semiconductor film (B) was formed.
Similarly to the oxide semiconductor film (A), the dye was adsorbed to the oxide semiconductor film (B). Thereafter, a photoelectrochemical cell (B) was prepared in the same manner as in the photoelectrochemical cell A, and the photoelectric conversion efficiency was measured. The results are shown in Table 9.

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

(Photoelectrochemical cell (D))
18.3 g of titanium tetrachloride was diluted with pure water to obtain an aqueous solution containing 1.0% by mass in terms of TiO ₂ . While stirring this, 15% by mass of ammonia water was added to obtain a white slurry having a pH of 9.5. This slurry was filtered and washed, suspended in pure water to obtain a 0.6 mass% hydrated titanium oxide gel slurry as TiO ₂ , adjusted to pH 2 by adding hydrochloric acid thereto, put in an autoclave, and stirred at 180 ° C. for 5 hours. The titania colloidal particles (D) were prepared by performing hydrothermal treatment for a period of time under saturated vapor pressure.
Next, titania colloidal particles (D) are concentrated to 10% by mass, and hydroxypropyl cellulose is added as a film forming aid so as to be 30% by mass in terms of TiO ₂ to form a semiconductor film. A coating solution was prepared. Next, the coating solution is applied onto a transparent glass substrate on which fluorine-doped tin oxide is formed as an electrode layer, dried naturally, and subsequently irradiated with 6000 mJ / cm ² of ultraviolet rays using a low-pressure mercury lamp to form a film. Cured. Furthermore, it heated at 300 degreeC for 30 minute (s), decomposed | disassembled and annealed hydroxypropyl cellulose, and formed the oxide semiconductor film (D).
Next, the dye of the present invention was adsorbed as a spectral sensitizing dye in the same manner as the oxide semiconductor film (A).
Then, the photoelectrochemical cell (D) was produced by the method similar to a photoelectrochemical cell (A), and the photoelectric conversion efficiency was measured. The results are shown in Table 9. Photoelectric conversion efficiency of 3.5% or more is ◎, 2.5% or more and less than 3.5% ○, 2.0% or more and less than 2.5% △, less than 2.0% A thing was evaluated as x, and a photoelectric conversion efficiency of 2.5% or more was regarded as acceptable.

表９より、本発明の色素を用いた場合には、光電気化学電池（Ａ）〜（Ｃ）の場合に特に光電変換効率が高いことがわかった。

From Table 9, when the pigment | dye of this invention was used, it turned out that especially photoelectric conversion efficiency is high in the case of a photoelectrochemical cell (A)-(C).

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

(1) Preparation of titanium oxide by heat treatment Using commercially available anatase-type titanium oxide (trade name ST-01, manufactured by Ishihara Sangyo Co., Ltd.), this is heated to about 900 ° C. and converted to blue kite-type titanium oxide. Further, it was heated to about 1,200 ° C. to obtain a rutile type titanium oxide.

(2) Synthesis of titanium oxide by wet method (titanium oxide 2 (blue kite type))
954 mL of distilled water is charged into a reaction vessel equipped with a reflux condenser and heated to 95. While maintaining the stirring speed at about 200 rpm, 46 mL of an aqueous solution of titanium tetrachloride (Ti content: 16.3 mass%, specific gravity 1.59, purity 99.9%) was added to this distilled water at a speed of about 5.0 mL / min. It was dripped at the reaction tank. At this time, care was taken not to lower the temperature of the reaction solution. As a result, the titanium tetrachloride concentration was 0.25 mol / L (2% by mass in terms of titanium oxide). In the reaction vessel, the reaction solution started to become cloudy immediately after dropping, but kept at the same temperature. After the dropping was completed, the temperature was further raised and heated to the vicinity of the boiling point (104 ° C.). The reaction was terminated.
The sol obtained by the reaction was filtered, and then powdered using a vacuum dryer at 60 ° C. As a result of quantitative analysis of this powder by X-ray diffractometry, the ratio of (peak intensity on the surface of blue kite type 121) / (peak intensity at the position where the three overlap) is 0.38, (rutile main peak intensity) / The ratio (peak intensity at the position where the three lines overlap) was 0.05. From these, the titanium oxide was crystallinity of about 70.0% by mass for the brookite type, about 1.2% by mass for the rutile type, and about 28.8% by mass for the anatase type. Further, when the fine particles were observed with a transmission electron microscope, the average particle diameter of the primary particles was 0.015 μm.

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

(Production and evaluation of dye-sensitized photoelectric conversion device)
A photoelectric conversion element having the configuration shown in FIG. 1 of JP-A No. 2000-340269 was produced as follows using titanium oxide prepared by the above titanium oxides 1 to 3 as a semiconductor.
A glass substrate was coated with fluorine-doped tin oxide to form a conductive transparent electrode. A paste using each titanium oxide particle as a raw material was formed on the electrode surface, applied to a thickness of 50 μm by a bar coating method, and then baked at 500 ° C. to form a thin layer having a thickness of about 20 μm. Next, about the pigment | dye shown in Table 10, the ethanol solution with a density ^| concentration of 3 * 10 < ^-4 > mol / L was prepared, the glass substrate in which the said titanium oxide thin layer was formed in this was immersed, and it hold | maintained at room temperature for 12 hours. .

  A photoelectric conversion element having the configuration shown in FIG. 1 of JP-A No. 2000-340269 was prepared using an iodine salt of tetrapropylammonium as an electrolytic solution and an acetonitrile solution of lithium iodide and using platinum as a counter electrode. The photoelectric conversion was performed by irradiating the above element with light from a 160 w high-pressure mercury lamp (the infrared part was cut by a filter) and measuring the photoelectric conversion efficiency at that time. The results are shown in Table 10. Photoelectric conversion efficiency of 3.5% or more is ◎, 2.5% or more and less than 3.5% ○, 2.0% or more and less than 2.5% △, less than 2.0% A product was evaluated as x, and a conversion efficiency of 2.5% or more was regarded as acceptable.

表１０より、本発明の色素を用いた光電変換素子の変換効率は高いことがわかった。

From Table 10, it turned out that the conversion efficiency of the photoelectric conversion element using the pigment | dye of this invention is high.

[Experiment 6]
Photoelectrochemical cells were fabricated as semiconductor electrodes using titanium oxides having different particle sizes, and the characteristics were evaluated.
[Preparation of paste]
First, a paste for forming a semiconductor layer or a light scattering layer of a semiconductor electrode constituting the photoelectrode was prepared by the following procedure.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(Photoelectrochemical cell 1)
A photoelectrode having the same configuration as the photoelectrode 12 shown in FIG. 5 described in JP-A-2002-289274 is prepared by the following procedure, and further, using the photoelectrode, a dye-sensitized type other than the photoelectrode is used. A photoelectrochemical cell 1 having a configuration similar to that of the solar cell 20 and having a size of 10 mm in length and 10 mm in width was produced.

A transparent electrode in which a fluorine-doped SnO ₂ conductive film (film thickness: 500 nm) was formed on a glass substrate was prepared. Then, the paste 2 was screen-printed on the SnO ₂ conductive film and then dried. Then, it baked on the conditions of 450 degreeC in the air. Furthermore, by repeating this screen printing and baking using the paste 4, a semiconductor electrode having the same configuration as the semiconductor electrode 2 shown in FIG. 5 on the SnO ₂ conductive film (the area of the light receiving surface is 10 mm long and 10 mm wide). A thickness of 10 μm; a thickness of the semiconductor layer is 6 μm, a thickness of the light scattering layer is 4 μm, and the content of the rod-like TiO ₂ particles 1 contained in the light scattering layer is 30% by mass). The photoelectrode which does not contain was produced.

Next, the pigment | dye was made to adsorb | suck to a semiconductor electrode as follows. First, anhydrous ethanol dehydrated with magnesium ethoxide was used as a solvent, and the dye of the present invention was dissolved therein so that the concentration thereof was 3 × 10 ⁻⁴ mol / L to prepare a dye solution. Next, the semiconductor electrode was immersed in this solution, whereby about 1.5 mmol / m ² of the dye was adsorbed on the semiconductor electrode, and the photoelectrode 10 was completed.

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

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

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

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

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

(Photoelectrochemical cell 3)
The light shown in FIG. 5 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 1 was used as the semiconductor layer forming paste and the paste 4 was used as the light scattering layer forming paste when the semiconductor electrode was manufactured. A photoelectrode and photoelectrochemical cell 3 having the same configuration as the electrode 10 and the photoelectrochemical cell 20 shown in FIG. 3 described in JP-A-2002-289274 were produced. The semiconductor electrode has a light receiving surface area of 10 mm in length, 10 mm in width, and 10 μm in thickness; the thickness of the semiconductor layer is 5 μm; the thickness of the light scattering layer is 5 μm; and rod-like TiO ₂ particles contained in the light scattering layer The content of 1 was 30% by mass.

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

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

(Photoelectrochemical cell 6)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemical process were performed in the same manner as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 9 was used as the light scattering layer forming paste. A battery 6 was produced. The content ratio of the rod-shaped TiO ₂ particles 4 contained in the light scattering layer of the semiconductor electrode was 30 wt%.

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

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

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

(Photoelectrochemical cell 10)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemical process were performed in the same manner as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 14 was used as the light scattering layer forming paste. Battery 10 was produced. The content ratio of the rod-shaped TiO ₂ particles 9 contained in the light scattering layer of the semiconductor electrode was 30 wt%.

(Photoelectrochemical cell 11)
Similar to the photoelectrochemical cell 1 except that a semiconductor electrode composed of only a semiconductor layer using only the paste 2 (the area of the light receiving surface is 10 mm long, 10 mm wide, and 10 μm thick) was produced in the manufacture of the semiconductor electrode. The photoelectrode and the photoelectrochemical cell 11 were produced by the procedure described above.

(Photoelectrochemical cell 12)
In the production of the semiconductor electrode, the photoelectrochemical cell 12 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 7 was used as the light scattering layer forming paste. Produced. The content ratio of the rod-shaped TiO ₂ particles 2 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

[Battery characteristics test]
Using the dyes described in Table 11, photoelectrochemical cells 1 to 12 were prepared, a battery characteristic test was performed, and photoelectric conversion efficiency was measured. The battery characteristic test was performed by irradiating 1000 W / m 2 of pseudo sunlight from a xenon lamp that passed through an AM1.5 filter using a solar simulator (manufactured by WACOM, WXS-85H). Current-voltage characteristics were measured using an IV tester, and energy conversion efficiency (%) was determined. The results are shown in Table 11. The results are: conversion efficiency of 3.5% or more ◎, 2.5% or more of less than 3.5% ○, 2.0% or more of less than 2.5% △, 2.0% Less than that was evaluated as x, and those with a conversion efficiency of 2.5% or more were accepted.

表１１に示すように、本発明の色素を用いた光電気化学電池は、いずれも変換効率が高いことがわかった。

As shown in Table 11, it was found that all of the photoelectrochemical cells using the dye of the present invention have high conversion efficiency.

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

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

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

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

  When the amount of water desorbed when titanium oxide, P25 powder (trade name, manufactured by Degussa) was heated at 300 ° C. was quantified by Karl Fischer titration, 0.253 mg of water was contained in 0.1033 g of titanium oxide fine powder. It was included. That is, since the titanium oxide fine powder contained about 2.5 wt% of water, the metal oxide fine particle powder was heat-treated in an oven at 450 ° C. for 30 minutes before mixing with the metal alkoxide, and stored in a desiccator after cooling. Used.

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

The molar concentration ratio between the metal oxide fine particles and the metal alkoxide is appropriately adjusted according to the metal oxide fine particle diameter so that the amorphous layer generated by hydrolysis of the metal alkoxide is not excessively thick and the particles can be sufficiently bonded to each other. did. All metal alkoxides were 0.1M ethanol solutions. When mixing titanium oxide fine particles and titanium (IV) tetraisopropoxide (TTIP), 3.55 g of 0.1M TTIP solution was mixed with 1 g of titanium oxide fine particles. At this time, the titanium oxide concentration in the obtained paste was about 22% by mass, and the viscosity was appropriate for coating. Moreover, the titanium oxide, TTIP, and ethanol at this time were 1: 0.127: 3.42 by mass ratio, and 1: 0.036: 5.92 by molar ratio.
Similarly, a mixed paste of titanium oxide fine particles and an alkoxide other than TTIP was prepared so that the fine particle concentration was 22% by mass. In the paste using zinc oxide and tin oxide fine particles, the content was 16% by mass. In the case of zinc oxide and tin oxide, the metal alkoxide solution was mixed at a ratio of 5.25 g to 1 g of the metal oxide fine particles.

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

  In this embodiment, the layer thickness of the amorphous metal oxide produced by the decomposition of the metal alkoxide is in the range of about 0.1 to 0.6 nm. A range of about 0.05 to 1.3 nm was suitable for room temperature film formation by this method.

(Applying paste on conductive substrate and air-drying treatment)
Two adhesive tapes as spacers on a polyethylene terephthalate (PET) film substrate (20Ω / cm ² ) with tin-doped indium oxide (ITO) conductive film or a glass substrate (10Ω / cm ² ) with fluorine-doped tin oxide (FTO) conductive film The pastes were applied in parallel at regular intervals, and each paste prepared according to the above method was uniformly applied using a glass rod.

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

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

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

(Dye adsorption)
The dye of the present invention was used as a sensitizing dye, and a 0.5 mM ethanol solution was prepared. In this example, the porous film produced by the above process was dried in an oven at 100 ° C. for 1 hour, then immersed in a sensitizing dye solution, and allowed to stand at room temperature for 50 minutes to adsorb the sensitizing dye on the titanium oxide surface. did. The sample after adsorption of the sensitizing dye was washed with ethanol and air-dried.

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

The battery performance was evaluated by photocurrent action spectrum measurement under irradiation with a constant number of photons (1016 cm ⁻² ) and IV measurement under irradiation with AM1.5 simulated sunlight (100 mW / cm ² ). A CEP-2000 type spectral sensitivity measuring device manufactured by Spectrometer Co., Ltd. was used for these measurements.
The photoelectric conversion characteristics of the obtained photoelectrochemical cell were evaluated, and the results are summarized in Table 12. A photoelectric conversion efficiency of 2.5% or more is ◎, 2.0% or more and less than 2.5% ○, 1.5% or more and less than 2.0% △, less than 1.5% Things were evaluated as x, and those with a photoelectric conversion efficiency of 2.0% or more were accepted.

表１２において、「ＵＶオゾン」、「ＵＶ」、「乾燥」の欄はそれぞれ、多孔質膜の形成後、増感色素吸着前における、ＵＶオゾン処理、ＵＶ照射処理、乾燥処理の有無を表す。処理したものが「○」であり、処理なしのものが「×」である。
表１２の「ＴｉＯ_２の前処理_」の欄は、酸化チタン微粒子の前処理（４５０℃のオーブンで３０分間熱処理）の有無を示す。試料番号７−６、７−１４、７−３０は、高ＴＴＩＰ濃度（酸化チタン：ＴＴＩＰのモル比が１：０．３５６）のペーストを用いた試料を表す。他の試料は全て酸化チタン：ＴＴＩＰ＝１：０．０３５６のペーストを用いた。

In Table 12, the columns of “UV ozone”, “UV”, and “dry” indicate the presence / absence of UV ozone treatment, UV irradiation treatment, and drying treatment after formation of the porous film and before sensitizing dye adsorption. The processed one is “◯”, and the unprocessed one is “×”.
The column of _“ Pretreatment of TiO ₂ ” in Table 12 indicates the presence or absence of pretreatment of titanium oxide fine particles (heat treatment in an oven at 450 ° C. for 30 minutes). Sample numbers 7-6, 7-14, and 7-30 represent samples using a paste having a high TTIP concentration (titanium oxide: TTIP molar ratio is 1: 0.356). All other samples used a paste of titanium oxide: TTIP = 1: 0.0356.

  From the results shown in Table 12, when the dye of the present invention is used, the photoelectricity is measured regardless of the presence or absence of UV ozone treatment, UV irradiation treatment, and drying treatment after the formation of the porous film and before adsorption of the sensitizing dye. It was found that the conversion efficiency of the chemical battery was high.

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

A conductive film was formed on a glass substrate by sputtering tin oxide doped with fluorine as a transparent conductive film. Dispersion liquid containing anatase-type titanium oxide particles on this conductive film (
Mixing 32g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) with 100mL of a mixed solvent consisting of water and acetonitrile in a volume ratio of 4: 1 and using a rotating / revolving mixing conditioner A semiconductor fine particle dispersion obtained by uniformly dispersing and mixing was applied, and then sintered at 500 ° C. to form a photosensitive layer having a thickness of 15 μm. In this photosensitive layer, no. 1-No. 8 benzimidazole compound electrolyte was added dropwise.
A frame type spacer (thickness: 25 μm) made of a polyethylene film was placed thereon, and this was covered with a platinum counter electrode to produce a photoelectric conversion element.
The obtained photoelectric conversion element was irradiated with light having an intensity of 100 mW / cm ^{2 using} a Xe lamp as a light source. Table 13 shows the obtained open circuit voltage and photoelectric conversion efficiency. The open circuit voltage is 6.3V or more, ◎, 6.0V or more and less than 6.3V is indicated as ◯, 5.7V or more and less than 6.0V is indicated as △, and less than 5.7V is indicated as ×. . Photoelectric conversion efficiency is ◎ if it is 3.5% or more, ○ if it is 2.5% or more and less than 3.5%, △ if it is 2.0% or more and less than 2.5%, or less than 2.0% Was displayed as x. An open circuit voltage of 6.0 V or higher and a photoelectric conversion efficiency of 2.5% or higher were accepted.
Table 13 also shows the evaluation results for the photoelectric conversion element using the electrolytic solution to which no benzimidazole compound was added.

表１３の結果から、本発明の色素を用いた光電変換素子は、開放電圧及び光電変換効率ともに合格レベルにあることがわかった。

From the results in Table 13, it was found that the photoelectric conversion element using the dye of the present invention was at an acceptable level for both the open circuit voltage and the photoelectric conversion efficiency.

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

  First, P25 powder having an average particle diameter of 25 nm (trade name, manufactured by Degussa), titanium oxide particles having a different particle diameter, and P200 powder (average particle diameter: 200 nm, product name, manufactured by Degussa) were used. And P200 are 15% by mass, and the mass ratio of P25 and P200 is P25: P200 = 30: 70, so that acetylacetone, ion-exchanged water, surfactant (manufactured by Tokyo Chemical Industry Co., Ltd.) , Trade name: “Triton-X”) and kneaded to prepare a slurry for forming a second layer (hereinafter referred to as “slurry 1”).

  Next, a slurry for forming a first layer (P1 content; 15 mass%; hereinafter, “slurry 2” is prepared by the same preparation procedure as that of the slurry 1 except that only P25 is used without using P200. Was prepared).

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

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

Next, an ethanol solution of the dye of the present invention (sensitizing dye concentration; 3 × 10 ⁻⁴ mol / L) was prepared as a sensitizing dye. The photoelectrode 10 was immersed in this solution and allowed to stand for 1 hour under a temperature condition of 40 ° C. to adsorb the sensitizing dye. Thereafter, in order to improve the open circuit voltage Voc, the semiconductor electrode after dye adsorption was immersed in an acetonitrile solution of 4-tert-butylpyridine for 15 minutes, and then dried in a nitrogen stream kept at 25 ° C., and the photoelectrode 10 Was completed.

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

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

  Next, a spacer S (trade name: “HIMILAN”, ethylene / methacrylic acid random copolymer ionomer film) manufactured by Mitsui Dupont Polychemical Co., Ltd. having a shape matched to the size of the semiconductor electrode was prepared. As shown in FIG. 1 described in 15613, the photoelectrode and the counter electrode were opposed to each other through a spacer, and each was bonded by thermal welding to obtain a battery casing (no electrolyte filled).

  Next, after injecting the liquid electrolyte into the housing from the hole of the counter electrode, the hole is closed with a member made of the same material as the spacer, and this member is thermally welded to the hole of the counter electrode to seal the hole. 1 was completed.

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

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

(Electrochemical battery 4)
Comparative photoelectrochemistry in the same procedure and conditions as in the photoelectrochemical cell 1 except that lithium iodide was added instead of zinc iodide in the liquid electrolyte, and the concentration of lithium iodide in the liquid electrolyte was 100 mmol / L. Battery 2 was produced.

(Battery characteristics evaluation test)
The photoelectric conversion efficiency (%) was measured for the photoelectrochemical cells 1 to 4 by the following procedure.

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

  About each photoelectrochemical cell, the current-voltage characteristic was measured at room temperature using the IV tester, and the initial value of photoelectric conversion efficiency [%] was calculated | required from these. The obtained results are shown as “fresh” in Table 14 (1 Sun irradiation conditions). In addition, with respect to the photoelectrochemical cells 1 to 4 under operating conditions of 60 ° C., 1 Sun irradiation and 10Ω load, the rate of decrease in photoelectric conversion efficiency was measured after 80 hours at 80 ° C., and the durability evaluation test obtained The results are also shown in Table 14. The conversion efficiency of Fresh is ◎ for those with 3.5% or more, ○ for those with 2.5% to less than 3.5%, △, 2.0% for those with 2.0% or more but less than 2.5% Less than were shown as x. An initial value of conversion efficiency of 2.5% or more and a decrease rate of photoelectric conversion efficiency of 20% or less after 300 hours at 80 ° C. was regarded as acceptable.

表１４に示した結果からわかるように、本発明の色素を用いた光電気化学電池は、電解質にヨウ化亜鉛を添加した場合でも、光電変換効率は優れたものであることがわかった。

As can be seen from the results shown in Table 14, it was found that the photoelectrochemical cell using the dye of the present invention had excellent photoelectric conversion efficiency even when zinc iodide was added to the electrolyte.

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

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

3. Production of Photoelectrochemical Cells Three types of photoelectrochemical cells a to c were produced by the following method. About these photoelectrochemical cells, the photoelectrochemical cells of sample numbers 10-1 to 10-9 were obtained using the dyes shown in Table 15, the nitrogen-containing polymer compound α, and the electrophile β.

(A) Production of Photoelectrochemical Battery a As a solvent, a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 was used. To this solvent, iodine and an iodine salt of 1-methyl-3-hexylimidazolium as an electrolyte salt were added to prepare a solution containing 0.5 mol / L electrolyte salt and 0.05 mol / L iodine. To this solution, 10 parts by mass of the following nitrogen-containing polymer compound α was added to 100 parts by mass of (solvent + nitrogen-containing polymer compound + electrolyte salt). Furthermore, 0.1 mol of electrophile β was mixed with the nitrogen-containing polymer compound α to obtain a uniform reaction solution.

On the other hand, on the dye-sensitized titanium oxide fine particle layer of electrode A, a platinum thin film side of a counter electrode made of a glass plate on which platinum is vapor-deposited through a spacer is placed, and the conductive glass plate and the platinum vapor-deposited glass plate are fixed. did. The open end of the obtained assembly was immersed in the electrolyte solution, and the reaction solution was infiltrated into the dye-sensitized titanium oxide fine particle layer by capillary action.
Subsequently, it heated at 80 degreeC for 30 minutes, and the crosslinking reaction was performed. Thus, as shown in FIG. 2 of JP 2000-323190 A, the dye-sensitized titanium oxide fine particle layer 20, the electrolyte layer 30, the platinum thin film 42, and the glass plate are formed on the conductive layer 12 of the conductive glass plate 10. A photoelectrochemical cell a-1 (sample number 10-1) in which the counter electrode 40 composed of 41 was sequentially laminated was obtained.
Further, photoelectrochemical cells a-2 to a-3 were obtained in the same manner as in the above step except that the dye was changed as shown in the table.

(B) Production of photoelectrochemical cell b Electrode A (20 mm × 20 mm) composed of a titanium oxide fine particle layer adsorbed with a dye as described above was superimposed on a platinum-deposited glass plate of the same size via a spacer. . Next, an electrolyte solution (iodine 0.05 mol / L using a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 as a solvent using a capillary phenomenon in the gap between both glass plates, lithium iodide 0 0.5 mol / L solution) was infiltrated to prepare a dye-sensitized solar cell b-1 (Sample No. 10-2).
In addition, photoelectrochemical cells b-2 to b-3 were obtained in the same manner as in the above step except that the sensitizing dye was changed as shown in the table.

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

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

  Alligator clips were connected to the conductive glass plate 10 and the platinum-deposited glass plate 40 of the above-described photoelectrochemical cell, and each alligator clip was connected to a current-voltage measuring device (Keutley SMU238 type). This was irradiated with simulated sunlight from the conductive glass plate 10 side, and the generated electricity was measured with a current-voltage measuring device. Table 15 summarizes the initial value (fresh) of the conversion efficiency of the photoelectrochemical cell thus determined and the rate of decrease in conversion efficiency after 300 hours of continuous irradiation. The conversion efficiency of Fresh is ◎ for those with 3.5% or more, ○ for those with 2.5% to less than 3.5%, △, 2.0% for those with 2.0% to less than 2.5% Less than that was displayed as x, the conversion efficiency initial value of 2.5% or more was passed, and the conversion efficiency reduction rate during continuous irradiation for 300 hours was 20% or less.

表１５に示した結果からわかるように、本発明の色素を用いた光電気化学電池はこの場合でも変換効率が高く、耐久性も優れたものであることがわかった。

As can be seen from the results shown in Table 15, it was found that the photoelectrochemical cell using the dye of the present invention also has high conversion efficiency and excellent durability.

[Experiment 11]
A porous layer of TiO ₂ was applied onto FTO glass by screen printing using a suspension prepared by a sol-gel method, and baked at 450 ° C. The dye was adsorbed by immersing it in a 10 ⁻⁴ mol / L ethanol solution of the dye A-2 of the present invention and the sensitizing dye S-1. Next, 100 mg of 2,2 ′, 7,7′-tetrakis (diphenylamino) -9,9′-spirobifluorene was dissolved in 5 ml of chloroform. The solution was soaked into the pores of the layer by lightly applying it to the dye surface. A drop of the solution was then placed directly on the surface and dried at room temperature. The coated support was then attached to a vapor deposition apparatus and further 2,2 ′, 7,7′-tetrakis (diphenylamino) -9,9′-spiro having a thickness of 100 nm by thermal vapor deposition under a vacuum of about 10 ⁻⁵ mbar. A layer of bifluorene was applied. Furthermore, a gold layer having a thickness of 200 nm was coated on the coated support as a counter electrode in a vapor deposition apparatus.
The sample thus prepared was attached to an optical device including a high-pressure lamp, an optical filter, a lens and a mounting. The intensity could be changed by using a filter and moving the lens. The gold layer and the SnO 2 layer were contacted and attached to the device shown in the current measuring device while the sample was irradiated. For the measurement, light having a wavelength of less than 430 nm was blocked using an appropriate optical filter. Furthermore, the apparatus was adjusted so that the intensity of the radiation was approximately equal to about 1000 W / m ² ).
Contacts were made on the gold layer and the SnO ₂ layer, and both contacts were connected to a potentiostat while the sample was irradiated. The sample using the sensitizing dye S-1 without applying an external voltage produced a current of about 90 nA, while the sample using the dye C-18 of the present invention produced a current of about 190 nA. In both samples, the current disappeared if not irradiated.

[Experiment 12]
Also in the tandem cell prepared in the same manner as in Example 1 described in JP-A-2000-90989, the conversion efficiency is higher when the dye C-18 of the present invention is used than when the comparative dye S-1 is used. Was confirmed to be 2 to 3% higher.

[Experiment 13]
A sol solution was prepared by dropping 125 ml of titanium isopropoxide into 750 ml of a 0.1 M nitric acid aqueous solution (manufactured by Kishida Chemical Co., Ltd.) and heating at 80 ° C. for 8 hours to cause a hydrolysis reaction. The obtained sol solution is kept at 250 ° C. for 15 hours in a titanium autoclave for particle growth, and then subjected to ultrasonic dispersion for 30 minutes to obtain a colloidal solution containing titanium oxide particles having an average primary particle size of 20 nm. It was.

  The colloidal solution containing the titanium oxide particles obtained was slowly concentrated with an evaporator until the titanium oxide concentration was 10% by mass, and then polyethylene glycol (manufactured by Kishida Chemical Co., Ltd., weight average molecular weight: 200000) was added. By adding 40% by mass with respect to titanium oxide and stirring, a suspension in which titanium oxide particles were dispersed was obtained.

The prepared titanium oxide suspension was applied by the doctor blade method to the transparent conductive film 2 side of the glass substrate 1 on which the SnO ₂ film was formed as the transparent conductive film 2 to obtain a coating film having an area of about 10 mm × 10 mm. This coating film is pre-dried at 120 ° C. for 30 minutes, and further baked at 500 ° C. for 30 minutes in an oxygen atmosphere to become the first porous semiconductor layer of the first porous photoelectric conversion layer 4. The film thickness is 10 μm. About a titanium oxide film was formed.

Next, commercially available titanium oxide fine particles (manufactured by Teika, product name: TITANIX
JA-1, 4.0 g of particle size) and 0.4 g of magnesium oxide powder (Kishida Chemical Co., Ltd.) were placed in 20 mL of distilled water and adjusted to pH = 1 with hydrochloric acid. Further, zirconia beads were added, and this mixed solution was subjected to a dispersion treatment with a paint shaker for 8 hours. Thereafter, 40% of polyethylene glycol (manufactured by Kishida Chemical Co., Ltd., weight average molecular weight: 200000) was added in a mass ratio to titanium oxide and stirred to obtain a suspension in which titanium oxide particles were dispersed.

  On the first porous semiconductor layer of the glass substrate 1 on which the titanium oxide film of the first porous semiconductor layer was formed, the prepared titanium oxide suspension was applied by a doctor blade method to obtain a coating film. This coating film is pre-dried at 80 ° C. for 20 minutes, and further baked at about 500 ° C. for 60 minutes in an oxygen atmosphere to form the second porous semiconductor layer of the second porous photoelectric conversion layer 5. A titanium oxide film 1 having a thickness of about 22 μm was formed. When the haze ratio of the porous semiconductor layer was measured, it was 84%.

As a dye having a maximum sensitivity absorption wavelength region in the absorption spectrum (first dye) on the short wavelength side, the following merocyanine dye S-2 is dissolved in ethanol to obtain a first dye having a concentration of 3 × 10 ⁻⁴ mol / L. A dye solution for adsorption was prepared.

  The glass substrate 1 provided with the transparent conductive film 2 and the porous semiconductor layer 3 is immersed in a dye solution for adsorption of the first dye heated to about 50 ° C. for 10 minutes, and the first dye is applied to the porous semiconductor layer 3. Adsorbed. Thereafter, the glass substrate 1 was washed several times with absolute ethanol and dried at about 60 ° C. for about 20 minutes. Next, the glass substrate 1 was immersed in 0.5N hydrochloric acid for about 10 minutes, and then washed with ethanol to remove excess first dye adsorbed on the second porous semiconductor layer. Further, the glass substrate 1 was dried at about 60 ° C. for about 20 minutes.

Next, as the dye having the maximum sensitivity absorption wavelength region in the absorption spectrum on the long wavelength side (second dye), the dye A-10, A-36 of the present invention or the comparative dye S-1 is dissolved in ethanol, A dye solution for adsorption of the second dye having a concentration of 3 × 10 ⁻⁴ mol / L was prepared.

  The glass substrate 1 having the transparent conductive film 2 and the porous semiconductor layer 3 is immersed in a dye solution for adsorbing the second dye at room temperature and normal pressure for 15 minutes so that the second dye is adsorbed on the porous semiconductor layer 3. It was. Thereafter, the glass substrate 1 was washed several times with absolute ethanol and dried at about 60 ° C. for about 20 minutes. Here, when the haze ratio of the porous semiconductor layer was measured, they were 82% (when S-1 was used) and 83% (when the dye A-10 of the present invention was used).

  Next, dimethylpropylimidazolium iodide is dissolved in 3-methoxypropionitrile solvent so that the concentration is 0.5 mol / L, lithium iodide is 0.1 mol / L, and iodine is 0.05 mol / L. Thus, a redox electrolyte solution was prepared. The porous semiconductor layer 3 side of the glass substrate 1 provided with the porous semiconductor layer 3 on which the first dye and the second dye are adsorbed, and the counter electrode side support 20 made of ITO glass provided with platinum as the counter electrode layer 8. The photoelectrochemical cell was completed by installing it so as to face the platinum side, injecting the prepared redox electrolyte and sealing the periphery with an epoxy resin sealing material 9.

  Further, the second porous semiconductor layer is made the same layer as the first porous semiconductor layer, that is, the second porous semiconductor layer is formed using a titanium oxide suspension that forms the first porous semiconductor layer. Except for this, a titanium oxide film 2 was prepared in the same manner as the titanium oxide film 1, and a photoelectrochemical cell was similarly prepared and evaluated using the titanium oxide film 2. The haze ratio of the porous photoelectric conversion layer was 17% (when S-1 was used) and 18% (when the dye A-10 of the present invention was used).

本発明の色素を第２色素として用いた光電気化学電池は光電変換効率に優れ、この系でも有効であることがわかった。 The obtained photoelectrochemical cell was evaluated in measurement conditions: AM 1.5 (100 mW / cm 2). Photoelectric conversion efficiency is ◎ if it is 3.5% or more, ○ if it is 2.5% or more and less than 3.5%, △ if it is 2.0% or more and less than 2.5%, or less than 2.0% Were evaluated as x, and those with a photoelectric conversion efficiency of 2.5% or more were regarded as acceptable.

The photoelectrochemical cell using the dye of the present invention as the second dye was excellent in photoelectric conversion efficiency, and was found to be effective even in this system.

[Experiment 14]
Titanium oxide suspension was prepared by dispersing 4.0 g of commercially available titanium oxide particles (manufactured by Teika Co., Ltd., average particle size 20 nm) and 20 ml of diethylene glycol monomethyl ether for 6 hours with a paint shaker using hard glass beads. . Next, this titanium oxide suspension was applied to a glass plate (electrode layer) to which a tin oxide conductive layer had been previously attached using a doctor blade, pre-dried at 100 ° C. for 30 minutes, and then heated to 500 ° C. in an electric furnace. Was baked for 40 minutes to form a titanium oxide film (semiconductor material) on the glass plate. Separately, the dye of the present invention shown in Table 17 or the comparative dye was dissolved in ethanol to obtain a dye solution.

本発明の色素を用いた光電変換素子は、この系でも光電変換効率に優れることがわかった。 The concentration of this dye solution was 5 × 10 ⁻⁴ mol / L. Next, the glass plate on which the film-like titanium oxide is formed is placed in this solution, dye adsorption is performed at 40 ° C. for 40 minutes, and then drying is performed, so that the semiconductor material and the photoamplifier are placed on the glass plate. A photoelectric conversion layer made of a dye-sensitive dye was formed (Sample A). On the photoelectric conversion layer of Sample A, a toluene solution (1%) of polyvinylcarbazole (weight average molecular weight 3,000) as a hole transport material was applied and dried under reduced pressure to form a hole transport layer (Sample B). ). 1.95 g of ethyl carbazole as an intermolecular charge transfer complex and 2.03 g of 5-nitronaphthoquinone were dissolved in 100 mL acetone, and the obtained solution was repeatedly applied on the hole transport layer of Sample B to form a conductive layer. . Next, a gold electrode (counter electrode) was deposited on the conductive layer to obtain a photoelectric conversion element (Sample C). The obtained photoelectric conversion element (sample C) was irradiated with light having an intensity of 100 W / m ^{2 using} a solar simulator. The results are shown in Table 17. Conversion efficiency is 1.5% or more for ◎, 1.0% or more and less than 1.5% for ○, 0.5% or more and less than 1.0% for Δ, and less than 0.5%. Things were evaluated as x, and those with a conversion efficiency of 1.0% or more were regarded as acceptable.

It has been found that the photoelectric conversion element using the dye of the present invention is excellent in photoelectric conversion efficiency even in this system.

[Experiment 15]
(1) Formation of first photoelectric conversion layer
Commercial titanium oxide particles (manufactured by Teika Co., Ltd., average particle size 30 nm) 4.0 g and diethylene glycol monomethyl ether 20 mL were dispersed using a hard glass bead for 6 hours with a paint shaker to prepare a titanium oxide suspension. Next, this titanium oxide suspension was applied to a glass plate to which a tin oxide conductive layer had been previously attached using a doctor blade, preliminarily dried at 100 ° C. for 30 minutes, and then baked at 500 ° C. for 40 minutes. A titanium oxide film was obtained.
Separately from this, the aforementioned Ru-1 was dissolved in ethanol. The concentration of this dye was 3 × 10 ⁻⁴ mol / L. Next, the glass plate on which film-like titanium oxide is formed is put in this solution, and after dye adsorption at 720 minutes at 60 ° C., drying is performed to obtain the first photoelectric conversion layer (sample A) of the present invention. It was.

(2) Formation of second photoelectric conversion layer
Commercially available nickel oxide particles (Kishida Kagaku, average particle size 100 nm) 4.0 g and diethylene glycol monomethyl ether 20 ml were dispersed with a paint shaker for 8 hours using glass beads to obtain a nickel oxide suspension. Next, this titanium oxide suspension was applied to a glass plate to which a tin oxide conductive layer was adhered using a doctor blade, pre-dried at 100 ° C. for 30 minutes, and then baked at 300 ° C. for 30 minutes. Got.
Separately, as the second dye described in Table 18, the dye A-1, E-7, A-36 or comparative dye S-1 of the present invention is dissolved in dimethyl sulfoxide, and a second dye solution is prepared. Obtained. The concentrations of these dye solutions were all 1 × 10 ⁻⁴ mol / L. Next, the glass plate on which the film-like titanium oxide is formed is put in this solution, and dye adsorption is performed at 40 ° C. for 70 minutes, followed by drying to obtain the second photoelectric conversion layer (sample B) of the present invention. It was.

(3) Place the sample B on the sample A, put a liquid electrolyte between these two electrodes, seal this side surface with resin, attach a lead wire, and install the photoelectric conversion element (element Configuration C) was prepared. Note that the liquid electrolyte is a mixed solvent of acetonitrile / ethylene carbonate (volume ratio is 1: 4), tetrapropylammonium iodide and iodine having concentrations of 0.46 mol / L and 0.06 mol / L, respectively. What was dissolved in this way was used.

  Moreover, the transparent conductive glass plate which equipped the said sample A as one electrode and carry | supported platinum as a counter electrode was used. A liquid electrolyte was placed between the two electrodes, and this side surface was sealed with resin, and then a lead wire was attached to produce a photoelectric conversion element (element configuration D) of the present invention.

The obtained photoelectric conversion elements (samples C and D) were irradiated with light having an intensity of 1000 W / m ^{2 using} a solar simulator. Photoelectric conversion of 6.5% or more is ◎, 6.0% or more and less than 6.5% ○, 5.0% or more and less than 6.0% Δ, less than 5.0% A thing was evaluated as x, and a photoelectric conversion efficiency of 6.0% or more was regarded as acceptable.

本発明の色素を第２色素として用いた系でも光電変換効率に優れた光電変換素子を得られることがわかった。

It was found that a photoelectric conversion element having excellent photoelectric conversion efficiency can be obtained even in a system using the dye of the present invention as the second dye.

[Experiment 16]
Using a polymer electrolyte, a photoelectric conversion element was produced and evaluated for its performance.
The coating liquid for producing the titanium oxide film was 4.0 g of commercially available titanium oxide particles (manufactured by Teika Co., Ltd., trade name AMT-600, anatase type crystal, average particle size 30 nm, specific surface area 50 m ^{2 /} g) and diethylene glycol monomethyl. 20 mL of ether was dispersed with a paint shaker for 7 hours using glass beads to prepare a titanium oxide suspension. Using a doctor blade, this titanium oxide suspension was formed on a glass substrate 1 with SnO ₂ as a transparent conductive film having a film thickness of about 11 μm, an area of about 10 mm in length, and about 10 mm in width. The film was applied to the film side, preliminarily dried at 100 ° C. for 30 minutes, and then baked under oxygen at 460 ° C. for 40 minutes. As a result, a titanium oxide film A having a thickness of about 8 μm was produced.

この単量体をプロピレンカーボネート（以下、ＰＣと記載する）に２０質量％の濃度で溶解させ、また、熱重合開始剤としてアゾビスイソブチロニトリル（ＡＩＢＮ）をモノマー単位に対して１質量％の濃度で溶解させ、単量体溶液を作製した。
この単量体溶液を、以下の手順で、上述の酸化チタン膜に含浸させた。真空容器内にビーカー等の容器を設置し、その中に透明導電膜を具備した透明基板上の酸化チタン膜Ａを入れ、ロータリーポンプで約１０分間真空引きした。真空容器内を真空状態に保ちながら上記の単量体溶液をビーカー内に注入し、約１５分間含浸させ酸化チタン中に単量体溶液を十分に染み込ませた。ポリエチレン製セパレーター、ＰＥＴフィルムと押さえ板を設置し冶具にて固定した。その後、約８５℃で３０分間加熱することにより、熱重合させ高分子化合物を作製した。 Next, the dye F-22, A-36 of the present invention or the comparative dye S-1 was dissolved in absolute ethanol at a concentration of 3 × 10 ⁻⁴ mol / L to prepare a dye solution for adsorption. The dye solution for adsorption was adsorbed by putting the transparent substrate provided with the titanium oxide film and the transparent conductive film obtained above into a container and allowing it to penetrate for about 4 hours. Thereafter, it was washed several times with absolute ethanol and dried at about 60 ° C. for about 20 minutes.
Next, among the monomer units represented by the following general formula, a monomer composed of R as a methyl group, A as eight polyethylene oxide groups, two polypropylene oxide groups, and a butanetetrayl group as a central core Prepared. Here, n is an integer of 2-4.

This monomer is dissolved in propylene carbonate (hereinafter referred to as PC) at a concentration of 20% by mass, and azobisisobutyronitrile (AIBN) as a thermal polymerization initiator is 1% by mass with respect to the monomer unit. A monomer solution was prepared by dissolving at a concentration of 2%.
The monomer solution was impregnated with the above titanium oxide film by the following procedure. A container such as a beaker was placed in the vacuum container, and the titanium oxide film A on the transparent substrate provided with the transparent conductive film was placed therein, and was evacuated with a rotary pump for about 10 minutes. The above monomer solution was poured into a beaker while keeping the inside of the vacuum vessel in a vacuum state, and impregnated for about 15 minutes to sufficiently soak the monomer solution in titanium oxide. A polyethylene separator, a PET film and a pressing plate were installed and fixed with a jig. Then, it heated and polymerized by heating at about 85 degreeC for 30 minutes, and the high molecular compound was produced.

  Next, a redox electrolyte solution to be impregnated into the above polymer compound was prepared. The redox electrolyte solution was prepared by dissolving lithium iodide at a concentration of 0.5 mol / L and iodine at a concentration of 0.05 mol / L using PC as a solvent. The polymer compound prepared on the above-described titanium oxide film A was immersed in this solution for about 2 hours, so that the polymer compound was impregnated with the redox electrolyte solution to prepare a polymer electrolyte.

本発明の色素を用いて作製した光電変換素子は、素子Ａでも、素子Ｂでも、光電変換効率に優れ、この系でも有効であることがわかった。 Then, the electroconductive board | substrate which comprised the platinum film | membrane was installed, the periphery was sealed with the epoxy-type sealing agent, and the element A was created.
In addition, after the dye adsorption of the titanium oxide film A, the above-described monomer treatment is not performed, and lithium iodide with a concentration of 0.5 mol / L and iodine with a concentration of 0.05 mol / L are dissolved using PC as a solvent. The oxidized redox electrolyte solution was injected as it was between the counter electrode and sealed to prepare an element B. Using the elements A and B, light having an intensity of 1000 W / m ² was irradiated with a solar simulator. The results are shown in Table 19. Photoelectric conversion efficiency is ◎ if it is 3.5% or more, ○ if it is 2.5% or more and less than 3.5%, △ if it is 2.0% or more and less than 2.5%, or less than 2.0% Were evaluated as x, and those with a photoelectric conversion efficiency of 2.5% or more were regarded as acceptable.

It was found that the photoelectric conversion element produced using the dye of the present invention is excellent in photoelectric conversion efficiency in both the element A and the element B and is effective in this system.

[Experiment 17]
(Preparation of photoelectric conversion element)
The photoelectric conversion element shown in FIG. 1 was produced as follows.
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts.
Next, 32 g of anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) is mixed with 100 mL of a mixed solvent having a volume ratio of water and acetonitrile of 4: 1, and a rotating / revolving mixing conditioner is prepared. The resulting mixture was uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion. This dispersion was applied to a transparent conductive film and heated at 500 ° C. to produce a light receiving electrode.
Thereafter, similarly, a dispersion containing 40:60 (mass ratio) of silica particles and rutile-type titanium oxide is prepared, and this dispersion is applied to the light receiving electrode and heated at 500 ° C. to form an insulating porous material. Formed body. Next, a carbon electrode was formed as a counter electrode.
Next, the glass substrate on which the above-mentioned insulating porous body was formed was immersed in an ethanol solution of a sensitizing dye (mixed or single) described in Table 20 below for 1 hour. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² . As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / L) and iodine (0.1 mol / L) was used.

(Measurement of photoelectric conversion efficiency)
Simulated sunlight containing no ultraviolet rays was generated by passing the light of a 500 W xenon lamp (manufactured by Ushio) through an AM1.5G filter (manufactured by Oriel) and a sharp cut filter (KenkoL-42, trade name). The intensity of this light was 89 mW / cm ² . The produced photoelectric conversion element was irradiated with this light, and the generated electricity was measured with a current-voltage measuring device (Caseley 238 type, trade name). The results obtained by measuring the conversion efficiency of the photoelectrochemical cell thus obtained are shown in Table 20 below. Photoelectric conversion efficiency of 7.5% or more is ◎, 7.3% to less than 7.5% is ◯, 7.1% to less than 7.3% is △, less than 7.1% A product was evaluated as x, and a product having a conversion efficiency of 7.3% or more was regarded as acceptable.

本発明の色素を用いて作製された光電変換素子は、表２０に示されているように、一般式（１）で表される本発明の色素と、一般式（６）で表される色素を組み合わせた場合は、変換効率は７．５％以上と高い値を示した。これに対して、比較例では、変換効率は７．３％未満と不十分であった。

As shown in Table 20, the photoelectric conversion element produced using the dye of the present invention has the dye of the present invention represented by the general formula (1) and the dye represented by the general formula (6). When combined, the conversion efficiency showed a high value of 7.5% or more. On the other hand, in the comparative example, the conversion efficiency was insufficient at less than 7.3%.

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

Claims (13)

A dye comprising a compound represented by the following general formula (1) even without low, the photoelectric conversion device characterized by comprising a photoconductive layer and a semiconductor particle.

[In one general formula (1), Q is to display the tetravalent benzene or naphthalene, ^{X 1} and X ² is sulfur atom frames other independently represent a ^{C (R} 1) R ^2. Here, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R and R ′ each independently represents an aliphatic group . P ¹ and P ² are each independently a non-metallic atoms necessary or ^{P 30-1} below following general formula (3-1) is represented by ^{P 30-2} of the following general formula (3-2) Represents a group, P ¹ and P ² represent different structures. W ¹ represents a counter ion as necessary to neutralize the charge .
In lower following general formula (3-1) and ^{(3-2), P 30-1} or ^{P 30-2} is a ^{C * 31} is the terminal carbons, the general formula (1) ^{C * 1} and / or C ^{* 2} and carbon - are linked by carbon-carbon double bond. ]

[In one general formula (3-1) and (3-2), A and B represents a benzene ring or a naphthalene ring. V ³¹ and ^{V 31 'is} a hydrogen atom, an alkyl group, an alkyloxy group, diphenylamino group, p- aminophenyl group, 5-carboxy, 6-carboxy group, 5-sulfonic acid, 5-phosphonyl group, It represents a 5-phosphoryl group or a salt thereof . n 31 and n31 'represents an integer of 1 or more. When n 31 is 2 or more, V ³¹ may be the same or different, and when n 31 ′ is 2 or more, V ^{31 ′} may be the same or different.
V ³¹ or V ^{31 'may} have with each other to form a ring. P ¹ or at least one of ^{V 31} and ^{V 31} Ru substituents der of ^{P 2 'is} an alkyl group, an alkyloxy group, .sigma.p in Hammett rule selected from a diphenylamino group and p- aminophenyl group The value represents a negative substituent. R ³⁴ and ^{R 34 'is} to display the group represented by an oxygen atom or the following general formula (4-1) to (4-3).
Y ³¹ and ^{Y 31 'is} sulfur atom frames other represents a ^{C (R} 6) R ^7. R ⁶ and R ⁷ are hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded through a carbon atom, may be the same or different, they may form a ring bonded to each other Good.
R ³¹ and R ^{31 'represents} an aliphatic group, an aromatic group, or represents a heterocyclic group bonded through a carbon atom, which may have a substituent.
R ^{32, R 32} to ^{', R 33} and R ^33' each independently represents a hydrogen atom or an aliphatic group, which may have a substituent. ]

[In the general formula (4-1) ~ (4-3), Ra is was or hydrogen atom an aliphatic group. ] Dyes consisting of pre-Symbol compound represented by the general formula (1) is selected 5-carboxy, 6-carboxy group, 5-sulfonic acid, 5-phosphonyl group, a 5-phosphoryl group and salts thereof the photoelectric conversion device according to claim 1, characterized in that it comprises an acidic group. Before SL or an alkyl group of the general formula (1) Oyo ^{V 31} that put the beauty ^{V 31 ',} an alkyl group, .sigma.p value in Hammett rule selected from a diphenylamino group and p- aminophenyl group is negative It has a substituent, and the other has an acidic group selected from 5-carboxyl group, 6-carboxy group, 5-sulfonic acid group, 5-phosphonyl group, 5-phosphoryl group and salts thereof claim 1 or photoelectric conversion device according to 2. Wherein ^{R 34} or is ^{R 34 ',} before following general formula (4-1) to (4-3), characterized by being represented by claims 1 to 3 of any photoelectric conversion element according to item 1 . Wherein ^{R 34} or is ^{R 34 ',} the following general formula (5-1) or photoelectric conversion device according to any one of claims 1 to 4, characterized by being represented by (5-2) .

Before Symbol R ³⁴ or is R ^{34 ',} the photoelectric conversion device according to any one of claims 1 to 3, characterized in that an oxygen atom. Before SL photoconductor layer, the photoelectric conversion device according to any one of claims 1 to 6, characterized in that it comprises a dye comprising a compound represented by the following general formula (6).
M z (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (6)
[In the general formula (6), Mz represents a metal atom, LL ¹ is bidentate or represented by the following general formula (7) represents a tridentate ligand, LL ² the following general formula (8) in bidentate or represented represents the tridentate ligand. X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, 1 seat or bidentate ligand coordinated with a group selected from the group consisting of an alkoxy group and an aryloxy group, or it represents a halogen atom, carbonyl, dialkyl ketone, 1,3-diketone, carbonamide, 1 seat or bidentate ligand selected from the group consisting of thio carboxylic amide and thiourea. m1 represents an integer of 0 to 3, and when m1 is 2 or more, LL ¹ may be the same or different. m2 represents an integer of 1 to 3, when m2 is 2 or more, LL ² may be the same or different. m3 represents an integer of 0 to 3, and when m3 is 2 or more, Xs may be the same or different, and Xs may be linked to each other. CI represents a counter ion when a counter ion is necessary to neutralize the charge in the general formula (6). ]

[In one general formula ^(7), each of ^{R 51} and ^{R 52} independently or acidic group represents a group having an acidic group. R ⁵³ and ^{R 54} each independently represents a ^substituent, each ^{R 55} and ^{R 56} are independently or an aryl group or a heterocyclic group. d1 and d2 each represent an integer of 0 to 5. To L ¹ and L ² are each independently, an ethenylene group and / or represents a conjugated chain composed of ethynylene group. a1 and a2 each independently represents an integer of 0 to 3, a1 is or different and is R ⁵¹ when two or more same, R ⁵² when a2 is 2 or more may be the same or different . b1 and b2 each independently represents an integer of 0 to 3, b1 is or different and is ^{R 53} when two or more ^{same, R 53} may be linked with each other to form a ring, b2 When R is 2 or more, R ⁵⁴ may be the same or different, and R ⁵⁴ may be linked together to form a ring. b1 Oyo When beauty b2 are both 1 or ^more, may be connected to form a ring ^{R 53} and ^{R 54.} d3 is 0 or represents 1. ]

[In one general formula (8), Za, are each Zb and Zc independently, 5-membered ring or represents a non-metal atomic group which can form a 6-membered ring, c is 0 or represents 1. Provided that at least one of the rings Za, Zb and Zc is formed having an acid group. ] Prior following general formula (7), the photoelectric conversion device according to claim 7, characterized in that d1 and d2 is an integer of 1 or more. Before Symbol ^{R 55} or ^{R 56} is a photoelectric conversion device according to claim 7 or 8, characterized in that any one of the following formulas (9-1) - (9-7).

[One general formula (9-1) in ^{~ (9-7), R 59,} R 63, R 66, R 69 and ^{R 74} may the alkyl group which may have a substituent, an alkynyl group or an aryl group Represents. R ⁵⁷ , R ⁵⁸ , R ^{60 to} R ⁶² , R ⁶⁴ , R _h , R ⁶⁵ , R ⁶⁷ , R ⁶⁸ , R ^{70 to} R ⁷³ , R ⁷⁵ , R ⁷⁶ and R ^{78 to} R ⁸¹ are each independently hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a thioalkyl group, an aryl group, an aryloxy group, an arylthio group, an amino group, also heterocyclic group represents a halogen atom. R ⁵⁷ and ^{R 58, R} 60 ^{~R 62} and ^{R 64} and ^{R 65, R 67} and ^{R 68, R} 70 ^{~R 73} and ^{R 75} and ^{R 76} and ^R 78 ^{to R 81} are each ring May be formed. R ⁷⁷ and R ⁸² to present twice in the same characteristic group may be the same or different, represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or a heterocyclic group.
m1 to m6 each represents an integer of 1 to 5. Y and X are independently represents S, O, Se, and Te, or NR ^{83, R 83} represents a hydrogen atom, an alkyl group, an alkenyl group, an alkenyl group, an aryl group or a heterocyclic group. ] The electrically conductive substrate, the photoconductive layer, the photoelectric conversion according to any one of claims 1 to 9, characterized in that it has a structure obtained by laminating in this order beauty counter Oyo charge transport layer element. The photoelectric conversion device according to any one of claims 1 to 10 before Symbol dye is characterized in that adsorbed on the semiconductor fine particles. Photoelectrochemical cell characterized by comprising a photoelectric conversion device according to any one of 請 Motomeko 1-11. Even without low dye comprising a compound represented by the following general formula (1).

[In one general formula (1), Q is to display the tetravalent benzene or naphthalene, ^{X 1} and X ² is sulfur atom frames other independently represent a ^{C (R} 1) R ^2. Here, R ¹ and R ² each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded with a carbon atom. R and R ′ each independently represents an aliphatic group . P ¹ and P ² are each independently a non-metallic atoms necessary or ^{P 30-1} below following general formula (3-1) is represented by ^{P 30-2} of the following general formula (3-2) Represents a group, P ¹ and P ² represent different structures. W ¹ represents a counter ion as necessary to neutralize the charge .
In lower following general formula (3-1) and ^{(3-2), P 30-1} or ^{P 30-2} is a ^{C * 31} is the terminal carbons, the general formula (1) ^{C * 1} and / or C ^{* 2} and carbon - are linked by carbon-carbon double bond. ]

[In one general formula (3-1) and (3-2), A and B represents a benzene ring or a naphthalene ring. V ³¹ and ^{V 31 'is} a hydrogen atom, an alkyl group, an alkyloxy group, diphenylamino group, p- aminophenyl group, 5-carboxy, 6-carboxy group, 5-sulfonic acid, 5-phosphonyl group, It represents a 5-phosphoryl group or a salt thereof . n 31 and n31 'represents an integer of 1 or more. When n 31 is 2 or more, V ³¹ may be the same or different, and when n 31 ′ is 2 or more, V ^{31 ′} may be the same or different.
V ³¹ or V ^{31 'may} have with each other to form a ring. P ¹ or at least one of ^{V 31} and ^{V 31} Ru substituents der of ^{P 2 'is} an alkyl group, an alkyloxy group, .sigma.p in Hammett rule selected from a diphenylamino group and p- aminophenyl group The value represents a negative substituent. R ³⁴ and ^{R 34 'is} to display the group represented by an oxygen atom or the following general formula (4-1) to (4-3).
Y ³¹ and ^{Y 31 'is} sulfur atom frames other represents a ^{C (R} 6) R ^7. R ⁶ and R ⁷ are hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group bonded through a carbon atom, may be the same or different, they may form a ring bonded to each other Good.
R ³¹ and R ^{31 'represents} an aliphatic group, an aromatic group, or represents a heterocyclic group bonded through a carbon atom, which may have a substituent.
R ^{32, R 32} to ^{', R 33} and R ^33' each independently represents a hydrogen atom or an aliphatic group, which may have a substituent. ]

[In the general formula (4-1) ~ (4-3), Ra is was or hydrogen atom an aliphatic group. ]

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