JP5756766B2 - 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, by using a specific polymethine dye, a proposal has been made to increase the light absorption at 800 nm and to provide a photoelectric conversion element with high conversion efficiency (for example, see Patent Documents 2 and 3). There is a need for a photoelectric conversion element using a sensitizing dye (long wavelength dye) that can be absorbed. However, when a long wavelength dye is used to form a photoelectric conversion element or a photoelectrochemical cell, generally, an open-circuit voltage is lowered by an additive or the like for producing a short-circuit current density, resulting in a problem that the conversion efficiency is lowered. . Moreover, since the internal loss inside the photoelectrochemical cell is increased, the fill factor (FF) is decreased. For this reason, when the wavelength-enhancing dye is used, the open circuit voltage (Voc) and the fill factor (FF) are lowered.
Therefore, for example, a photoelectric conversion element that absorbs light in a wavelength region exceeding 850 nm, has a higher open-circuit voltage (Voc) and fill factor (FF), and has a higher photoelectric conversion efficiency than a conventional long wavelength dye. There is a need for photoelectrochemical cells and dyes suitable for use therein.

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

  The problem of the present invention is, for example, that it absorbs light in a wavelength region exceeding 850 nm, has a higher open-circuit voltage (Voc) and fill factor (FF), and has a higher photoelectric conversion efficiency than a conventional long-wavelength dye. It is to provide a conversion element, a photoelectrochemical cell and a dye.

As a result of intensive studies, the present inventors have found that a polymethine dye having a specific structure having one acidic group or one group having an acidic group and having an electron withdrawing group other than the acidic group or acidic group is a semiconductor fine particle. It has been found that the efficiency of electron injection into the substrate can be improved, a high conversion efficiency can be obtained even in a wavelength region exceeding 850 nm, and the open-circuit voltage (Voc), fill factor (FF), and photoelectric conversion efficiency can both be increased. 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 the general formula (1), Q represents a benzene ring or a naphthalene ring ^group, X 1, ^{X 2} each independently represent a sulfur atom, an oxygen atom or ^{C (R a) R b,} . Here, R ^a and R ^b each independently represents 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 alkyl group or an aromatic group.
P ¹ and P ² are each independently a nonmetallic atom group necessary for forming a polymethine dye represented by P ¹¹ of the following general formula (2-1) or P ¹² of the following general formula (2-2) Indicates.
W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formulas (2-1) and (2-2), V represents a substituent.
One of V of P ¹ and P ² in the general formula (1) (referred to as Va) is an acidic group or a group having an acidic group, and the Va is only ^one of P ¹ and P ^2. It has. R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic). R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} and R ^{3 ′} each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded via a carbon atom. One or more of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va is a substituent having a positive σp value in Hammett's rule or The σp value in the Hammett rule is a group having a positive substituent.
Y and Y ′ each independently represent a sulfur atom, N (R ^d ) or C (R ⁶ ) (R ^{6 ′} ). R ⁶ and R ^{6 ′} represent a substituent. R ^d represents an alkyl group. n1 and n1 ′ represent an integer of 1 or more, and n2 represents an integer of 0 or more. The carbon-carbon double bond may be either E-type or Z-type. When n1 and n1 ′ are integers of 2 or more, a plurality of Vs may be the same or different, and a plurality of Vs may be bonded to each other to form a ring. ]
<2> Nonmetallic atom necessary to form a polymethine dye in which the acidic group or the group (Va) having an acidic group and a substituent having a positive σp value in Hammett's rule or a group having the substituent are bonded to each other The photoelectric conversion element according to <1>, wherein the group is one of P ¹¹ and P ¹² .
<3> The photoelectric conversion element according to <1> or <2>, wherein n2 is 0 or 1.
<4> Any one of <1> to <3>, wherein the exo double bond portion of the methenyl group of R ^{5 ′} is represented by the following general formula (3-1) or (3-2) Item 1. The photoelectric conversion element according to item 1.

[In General Formula (3-2), R ⁷ represents a hydrogen atom, an alkyl group, or an alkali metal. The carbon-carbon double bond may be either E-type or Z-type. ]
<5> The photoelectric conversion element according to any one of <1> to <3>, wherein R ^{5 ′} is a carbonyl group.
<6> Any one of <1> to <5>, wherein Va is a 5-carboxy group, a 5-sulfonic acid group, a 5-phosphonyl group, a 5-phosphoryl group, or a salt thereof. The photoelectric conversion element as described in 2.
<7> The photoelectric conversion element according to any one of <1> to < 6 >, wherein the photoreceptor layer further contains a dye composed of a compound represented by the following general formula (4).
Mz (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (4)
[In General Formula (4), Mz represents Ru, Os, Zn or Cu , LL ¹ represents a bidentate or tridentate ligand represented by the following General Formula (5), and LL ² represents the following General The bidentate or tridentate ligand represented by Formula (6) is represented. X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, A monodentate or bidentate ligand coordinated by a group selected from the group consisting of an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a halogen atom Represents a monodentate or bidentate ligand selected from the group consisting of carbonyl, dialkyl ketone, 1,3-diketone, carboximine, thiocarbonimine 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 required to neutralize the charge in the general formula (4). ]

[In General Formula (5), R ⁵¹ and R ⁵² each independently represent an acidic group or a group having an acidic group. R ⁵³ and R ⁵⁴ each independently represent a substituent, and R ⁵⁵ and R ⁵⁶ each independently represent an alkyl group, an aryl group or a heterocyclic group. d1 and d2 each represent an integer of 0 to 5. L ¹ and L ² each independently represents a conjugated chain composed of an ethenylene group and / or an 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. When b1 is 2 or more, R ⁵³ may be the same or different, and R ⁵³ may be linked to each other to form a ring. In the above, R ⁵⁴ may be the same or different, and R ⁵⁴ may be linked to each other to form a ring. When both b1 and b2 are 1 or more, R ⁵³ and R ⁵⁴ may be linked to form a ring. d3 represents 0 or 1. ]

[In General formula (6), Za, Zb, and Zc represent the nonmetallic atom group which can form a 5-membered ring or a 6-membered ring each independently, and c represents 0 or 1. However, at least one of the rings formed by Za, Zb and Zc has an acidic group. ]
<8> A photoelectrochemical cell comprising the photoelectric conversion element according to any one of <1> to <7>.
<9> A dye comprising at least a compound represented by the following general formula (1).

[In General Formula (1), Q represents a benzene ring group or a naphthalene group, and X ¹ and X ² each independently represent a sulfur atom, an oxygen atom, or C (R ^a ) R ^b . Here, R ^a and R ^b each independently represents 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 alkyl group or an aromatic group.
P ¹ and P ² are each independently a nonmetallic atom group necessary for forming a polymethine dye represented by P ¹¹ of the following general formula (2-1) or P ¹² of the following general formula (2-2) Indicates.
W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formulas (2-1) and (2-2), V represents a substituent.
One of V of P ¹ and P ² in the general formula (1) (referred to as Va) is an acidic group or a group having an acidic group, and the Va is only ^one of P ¹ and P ^2. It has. R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic). R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} and R ^{3 ′} each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded via a carbon atom. One or more of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va is a substituent having a positive σp value in Hammett's rule or The σp value in the Hammett rule is a group having a positive substituent.
Y and Y ′ each independently represent a sulfur atom, N (R ^d ) or C (R ⁶ ) (R ^{6 ′} ). R ⁶ and R ^{6 ′} represent a substituent. R ^d represents an alkyl group. n1 and n1 ′ represent an integer of 1 or more, and n2 represents an integer of 0 or more. The carbon-carbon double bond may be either E-type or Z-type. When n1 and n1 ′ are integers of 2 or more, a plurality of Vs may be the same or different, and a plurality of Vs may be bonded to each other to form a ring. ]

  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 extensive studies, the present inventors have found that a polymethine dye having a specific structure having one acidic group or one group having an acidic group and one or more electron withdrawing groups other than the acidic group or acidic group. The inventors have found that the efficiency of electron injection into semiconductor fine particles can be improved, a high conversion efficiency can be obtained even in a wavelength region exceeding 850 nm, and the open-circuit voltage (Voc), fill factor (FF), and photoelectric conversion efficiency can both be increased. Although the detailed reason is not certain, by having one acidic group or a group having an acidic group in the polymethine dye, the acidic group or the group having an acidic group bonded to the molecule is effectively applied to the semiconductor fine particles. An atom or group that can be adsorbed and has a positive σp value in Hammett's rule is considered to promote localization of HOMO (highest occupied orbital) / LUMO (lowest empty orbit) of the dye. Hereinafter, preferred embodiments of the present invention will be described.

  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 semiconductor fine particles 22 and a dye (sensitizing dye) 21, and the dye 21 is adsorbed to the semiconductor fine particles 22 at least in part (the dye is in an adsorption equilibrium state, Some may be present in the charge transfer layer.) The conductive support 1 on which the photoreceptor 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. The light incident on the photoreceptor layer 2 excites the dye. The excited dye has high energy electrons. Therefore, the electrons are transferred from the dye 21 to the conduction band of the semiconductor fine particles 22 and further reach the conductive support 1 by diffusion. At this time, the molecule of the dye 21 is an oxidant. While the electrons on the electrode work in the external circuit, the excited and oxidized dye receives electrons from the reducing agent (eg, I ⁻ ) in the electrolyte and returns to the ground state dye, thereby allowing the photoelectrochemical cell to Acts as At this time, the light receiving electrode 5 functions as a negative electrode of the battery.

In order to realize a longer wavelength in the sensitizing region of the sensitizing dye, it is necessary to reduce the HOMO / LUMO gap of the dye. Therefore, it is conceivable to increase the energy level of the HOMO of the dye and lower the LUMO as necessary. By increasing the energy level of the HOMO, the difference between the energy level of the HOMO of the dye and the energy level of the reducing agent (for example, I ⁻ ) in the electrolyte is reduced. Reduction rate is slow. In addition, when the LUMO energy level of the dye is lowered, the difference from the energy level of the conductive band of the semiconductor fine particles (for example, titanium oxide) is reduced, so that the electron injection efficiency is lowered, and the short-circuit current and the fill factor are reduced. Therefore, it is difficult to increase the photoelectric conversion efficiency.
On the other hand, it is conceivable to increase the electron injection efficiency by lowering the energy level of the conduction band of the semiconductor fine particles. In this method, the short circuit current can be increased, but the open circuit voltage is decreased.
In contrast, the present invention, for example, absorbs light even in a wavelength region exceeding 850 nm, and has a higher open-circuit voltage (Voc) and fill factor (FF) compared to conventional long-wavelength dyes. It has an excellent effect of high efficiency.

  The photoelectric conversion element of this embodiment has a photoreceptor having a layer of porous semiconductor fine particles on which an after-mentioned dye is adsorbed on a conductive support. At this time, a part of the dye dissociated in the electrolyte may be present. The photoreceptor is designed according to the purpose, and may have a single layer structure or a multilayer structure. The 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 represented by general formula (1) In the photoelectric conversion device of the present invention, a dye made of a compound represented by at least 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 a benzene ring group or a naphthalene ring group. X ¹ and X ² each independently represents ^a sulfur atom, an oxygen atom or C (R ^a ) R ^b . X ¹ and X ² are preferably a sulfur atom or C (R ^a ) R ^b , and most preferably C (R ^a ) R ^b . Here, R ^a and R ^b are each independently a hydrogen atom, an aliphatic group, an aromatic group (for example, an aryl group exemplified by R ⁵³ and R ⁵⁴ in the general formula (5) described later), or carbon The heterocyclic group couple | bonded with an atom (For example, the heterocyclic ring of the heterocyclic group illustrated by R ^{< 53>} , R ^{<54 >} in General formula (5) mentioned later is mentioned) is represented. R ^a and R ^b 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.), more preferably an alkyl group or a cycloalkyl group, and particularly preferably an alkyl group.
The positional relationship of binding to Q is not intended to illustrate the three-dimensional structure, binding to Q is, N (R ') X ² is bonded to either position, and N (R a position of X ^2') Including those bound by

R and R ′ each independently represents an alkyl group or an aromatic group. These may be substituted. 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 alkyl group is preferably 1-18, more preferably 1-12. Examples of the unsubstituted alkyl group and aromatic group include methyl, ethyl, n-propyl, n-butyl, cyclohexyl, phenyl, naphthyl, and the like.
R and R ′ are preferably alkyl groups.

In the general formula (1), P ¹ and P ² each independently form a polymethine dye represented by P ^{11 in the following} general formula (2-1) or P ¹² in the following general formula (2-2). The non-metallic atomic group necessary for this is shown. W ¹ represents a counter ion as necessary to neutralize the charge.

In general formulas (2-1) and (2-2), V represents a substituent. Examples of the substituent in V include substituents exemplified by R ^{51 to} R ⁵⁴ in the general formula (5) described later.
One of V of P ¹ and P ² in the general formula (1) (referred to as Va) is an acidic group or a group having an acidic group, and the Va is only ^one of P ¹ and P ^2. It has. R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic). R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} and R ^{3 ′} each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded via a carbon atom. Of these, specific examples of the aliphatic group, the aromatic group or the heterocyclic group bonded with a carbon atom include the aliphatic group, the aromatic group or the heterocyclic group bonded with a carbon atom mentioned in R ^a and R ^b. The ones mentioned above are mentioned.
One or more of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va is a substituent having a positive σp value in Hammett's rule or The σp value in the Hammett rule is a group having a positive substituent. Here, when R ^{5 ′} is a substituent having a positive σp value in Hammett's rule or a group having a positive σp value in Hammett's rule, preferably an atom or a double bond on exo (extracyclic) In the case of a methenyl group bonded to a substituent, the atom bonded to the exo (extracyclic) double bond is not an oxygen atom, but a substituent of a substituent other than an oxygen atom, for example, a nitrogen atom of = N or = C described later It is preferable to count the σp value of a substituent substituted with an atom or a carbon atom.
n2 represents an integer of 0 or more, and is preferably 0 or 1.
Here, the nonmetallic atom group necessary for forming a polymethine dye in which the acidic group or the group (Va) having an acidic group and an atom or group having a positive σp value in Hammett's rule is bonded is P ¹¹ and while it is preferably of P ^12, in this case, P ¹¹ and P ¹² does not have these groups it is preferred that V has at least one electron donating group. As such an electron donating group, an alkoxy group, an amino group, an alkylamino group, an arylamino group, and a phenyl group substituted by these are preferable.

Here, the acidic group is a substituent having a dissociative proton, and examples thereof include groups having a carboxyl group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and the like, and preferably a group having a carboxyl group. It is. Further, the acidic group may take a form of releasing a proton and dissociating, or may be a salt. In V, the above acidic group may be bonded directly to the benzene ring, or the acidic group may be bonded via a linking group. The acidic group is preferably a 5-carboxyl group, a 5-sulfonic acid group, a 5-phosphonyl group, a 5-phosphoryl group, or a salt thereof. The group having an acidic group may be a group in which the above acidic group is bonded via a linking group. Can be mentioned. In this specification, the position number (for example, 5 in the case of a 5-carboxyl group) is such that N (R ¹ ) or N (R ¹ ′) is 1 and Y or Y ′ is 3. Suppose that it is given counterclockwise.
For example, in the general formula (2-1), the position numbers are as follows.

Among V of P ¹ and P ² in the general formula (1), V other than Va, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} One or more of them have a positive σp value in Hammett's rule.
Here, the substituent constant σp value in Hammett's rule will be described. Hammett's rule is described in 1935 by L.L. 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 “Areas of Chemistry”, No. 122, 96-103, 1979 (Nankodo), Chem. Rev. 1991, 91, 165-195.
As the positive substituent constant σp value, halogen atom, nitro group, cyano group, sulfo group, carboxyl group, formyl group, acyl group, carbamoyl group, sulfamoyl group, mercapto group, alkyl or arylsulfonyl group, alkyl or An arylsulfinyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a perfluoroalkyl group, a heterocyclic group (for example, a heterocyclic ring is a pyridine ring, a pyrimidine ring, a 2-pyrimidinyl group, a 4-pyrimidinyl group, a 5-pyrimidinyl group, 2-thienyl group, 2-pyridyl group, 3-pyridinyl group, 4-pyridinyl group), phenyl group substituted by electron withdrawing group And particularly preferably a carboxyl group, a 3-carboxylphenyl group or Is 4-carboxylphenyl group).

Among V of P ¹ and P ² in the general formula (1), any one (Va) is an acidic group or a group having an acidic group, and the Va is present only in ^one of P ¹ and P ^2. And at least ^one of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va has a positive σp value in Hammett's rule By using a dye to which an object is bonded as a sensitizing dye, it is possible to increase the probability that electrons are present in the semiconductor fine particle layer on which the excited sensitizing dye is adsorbed when irradiated with light. Thereby, not only can light of a long wavelength be efficiently absorbed, but also the efficiency of electron injection into the semiconductor fine particle layer can be improved, and a high open circuit voltage (Voc) and fill factor (FF) can be realized.
Moreover, when both P ¹ and P ² are the general formula (2-2), those in which R ^{5 ′} of P ¹ and P ² are different are preferable.

  Although this mechanism is not clear, in the dye represented by the general formula (1), an acidic group or a group having an acidic group bonded to the molecule is adsorbed on the semiconductor fine particles, and σp in the Hammett rule It is thought that the atom or group having a positive value promotes HOMO / LUMO localization of the dye. By using the dye represented by the general formula (1), the open circuit voltage (Voc) and the fill factor (FF) are improved by separating the donor site and the acceptor site in the ground state of the dye in the molecule. It is presumed that by giving a large dipole moment to the dye, the change in polarity between the ground state and the excited state can be reduced, and the reorientation energy in the electrolyte is lowered to easily suppress the electron transfer.

A group of non-metallic atoms necessary to form a polymethine dye in which the acid group or the group (Va) having an acid group and an atom having a positive σp value in Hammett's rule or a group is bonded is represented by P ¹¹ and P ¹² . One of them is preferable. By making these groups or atoms one of P ¹¹ and P ¹² , reverse electron transfer from the semiconductor fine particle layer hardly occurs, the arrangement of the dyes is controlled to improve the surface coverage of the semiconductor fine particle layer, The redox couple can be prevented from approaching the semiconductor fine particle layer, and the open circuit voltage (Voc) and the fill factor (FF) can be improved.

R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic), and is represented by> C═R ^{51 ′} . Here,> C is a carbon atom on a 4-membered ring, R ^{51 ′} represents an oxygen atom or N (R ^c ) or a carbon atom having two substituents, and R ^c is a hydrogen atom or a substituent. Represents. R ^{51 ′} is preferably an oxygen atom or a carbon atom having two substituents, and is preferably a carbon atom having two substituents whose sum of σp in the Hammett rule of each oxygen atom or each substituent is positive. . Preferred examples of the substituent that substitutes for a carbon atom include the groups listed as those having the above-described substituent constant σp value positive. In the case of a carbon atom having two substituents, these two substituents may be bonded to each other to form a ring.
When R ^{51 ′} is N (R ^c ), examples of the substituent in R ^c include the substituents exemplified by R ⁵³ and R ⁵⁴ in the general formula (5) described later. R ^c is preferably a substituent group consisting of a hydrogen atom, an aliphatic group, an aromatic group, and an ester group (alkoxycarbonyl group, aryloxycarbonyl group, etc.), and the following can be mentioned. For example, 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, ethoxycarbonyl Can be mentioned. The exo double bond portion of the methenyl group of R ^{5 ′} is preferably an oxygen atom (carbonyl group). Thereby, it becomes possible to synthesize it cheaply and easily.

It is preferable that the exo double bond part of the methenyl group of R ^{5 ′} is represented by the following general formula (3-1) or (3-2). In General Formula (3-2), R ⁷ represents a hydrogen atom or an alkyl group. The carbon-carbon double bond may be either E-type or Z-type. The alkyl group preferably has 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, n-butyl, n-hexyl, isopropyl, and t-butyl, and more preferably methyl, n-butyl, and isopropyl. it can. Thereby, the twist of the conjugate more than necessary can be avoided.

Y and Y ′ each independently represent a sulfur atom, N (R ^d ) or C (R ⁶ ) (R ^{6 ′} ). R ⁶ and R ^{6 ′} represent a substituent. R ^d represents an alkyl group, preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group. R ⁶ and R ^{6 ′} each independently represent a substituent, and preferred examples of R ⁶ and R ^{6 ′} are aliphatic groups (preferably those having 1 to 12 carbon atoms such as methyl, ethyl, n-butyl, n -Hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl, etc.) or an aromatic group (preferably having 4 to 14 carbon atoms, such as phenyl, tolyl, naphthyl, etc.). R ⁶ and R ^{6 ′} are more preferably an aliphatic group (preferably having 1 to 12 carbon atoms such as methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n -Dodecyl, cyclohexyl, benzyl, etc.).
n1 and n1 ′ represent an integer of 1 or more, and n2 represents an integer of 0 or more. The carbon-carbon double bond may be either E-type or Z-type. When n1 and n1 ′ are integers of 2 or more, a plurality of Vs may be the same or different, and a plurality of Vs may be bonded to each other to form a ring. Here, when a plurality of V are bonded to each other to form a ring, the ring may be an alicyclic ring, an aromatic ring, or a heterocyclic ring, but an aromatic ring, particularly a benzene ring is preferable.
Here, the “substituent” defined by each group of the general formula (1), the general formula (2-1), and the general formula (2-2) is R ^{51 to} R ^{54 in} the general formula (5) described later. Specific examples of the substituent described in the above, a hydroxyl group, a mercapto group, and a sulfamoyl group.

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.

  The maximum absorption wavelength in the ethanol solution of the dye of the present invention represented by the general formula (1) 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.

As mentioned above, the compound which has the substituent represented by the alphabet followed by the skeleton represented by "T-number" is illustrated. (When V ₁ ′ has a substituent on the nitrogen, the alphabet is capitalized, otherwise it is represented by a lower case letter. When V ₁ ′ has a substituent, the alphabet has “′”, “” ”,“ “” ”Is attached to each of the corresponding substituents. Specifically, V ₁ ′ of“ ′ ”is —CH ₂ COC ₆ H ₅ , and V ₁ ′ of“ ”” is —CH ₂ C ₆ H. ₄ -4-CO _{2 H,} "'""ofV1' is _{-CH 2 C 6 H 4 -3-} CO 2 H.)
The basic structures in Tables 1 to 4 are as follows.
Table 1 Basic structures T-1 to 11, T-23 to 33, T-45 to 55
Table 2 Basic structures T-12 to 22, T-34 to 44, T-56 to 66
Table 3 Basic structures T-67 to 77, T-89 to 99
Table 4 Basic structures T-78 to 88, T100 to 110

Synthesis of a dye comprising the compound represented by the general formula (1) is described in Ukrainski Kimicheskii Zhurnal, Vol. 40 (No. 3), pages 253 to 258, Dies and Pigments, Vol. 21, pages 227 to 234 and these documents. This can be done with reference to the description of the documents cited in the document.
For example, the exemplified dye T-4-I ″ can be obtained by the following scheme. Other dyes can be obtained by the same method.

(A2) Dye composed of a compound represented by the general formula (4) In the photoelectric conversion element and the photoelectrochemical battery of the present invention, it is preferable to further include a dye composed of a compound represented by the following general formula (4). .
Mz (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (4)
The dye composed of the compound represented by the general formula (4) has a ligand LL ¹ and / or a ligand LL ² and, optionally, a specific functional group X coordinated to a metal atom. In some cases, it is kept electrically neutral by CI.
(A2-1) Metal atom Mz
Mz represents R u, Os, Zn or Cu, good Mashiku is Ru.

(A2-2) Ligand LL ¹
The ligand LL ¹ is a bidentate or tridentate ligand represented by the bidentate or tridentate ligand represented by the following general formula (5), 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.
R ⁵¹ and R ⁵² in the general formula (5) 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, —CON (CH 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 salts thereof, more preferably a carboxyl group or a salt thereof. R ⁵¹ and R ⁵² may be substituted on any carbon atom on the pyridine ring.

In the general formula (5), 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.), an alkenyl group (preferably an alkenyl group having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), an alkynyl group ( Preferably an alkynyl group having 2 to 20 carbon atoms such as ethynyl, butadiynyl, phenylethynyl and the like, a cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, 4 -Methylcyclohexyl and the like), an aryl group (preferably having 6 to 6 carbon atoms) 6 aryl groups such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, etc., heterocyclic groups (preferably 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 the number of carbon atoms 2-20 alkoxycarbonyl groups such as ethoxycal Nyl, 2-ethylhexyloxycarbonyl, etc.), an amino group (preferably an amino group having 0 to 20 carbon atoms, including an alkylamino group and an arylamino group, such as amino, N, N-dimethylamino, N, N -Diethylamino, N-ethylamino, anilino, etc.), sulfonamide groups (preferably sulfonamido groups having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc.), acyloxy groups ( Preferably an acyloxy group having 1 to 20 carbon atoms, such as acetyloxy, benzoyloxy, etc., 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 an acyl group having 1 to 20 carbon atoms) A mino group such as acetylamino, benzoylamino, etc., a cyano group, or a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), more preferably an alkyl group, an alkenyl group, an aryl group, hetero A cyclic 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 (5), 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 includes a carbon-carbon double bond, each double bond may be E-type or Z-type, 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 a1 is 0, a2 is preferably 1 or 2, and when a1 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 (4) is preferably 2 or 3, and preferably 2. Is more preferable.

(A2-3) Ligand LL ²
In the general formula (4), LL ² represents a bidentate or tridentate ligand. _{M 2} representing the number of ligands LL ² is an integer of 1 to 3, is preferably 1 or 2. When m ₂ is 2, LL ² may be the same or different.
Ligand LL ² is a bidentate or tridentate ligand represented by the following general formula (6).

In General Formula (6), 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 (6), 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 (7-1) to (7-8), the formula (7-1), (7-2), (7-4 ) Or (7-6), more preferably represented by formula (7-1) or (7-2), and represented by formula (7-1). Is most preferred.

In general formulas (7-1) to (7-8), 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, —CON (CH ₃ ) OH, etc.), A phosphoryl group (for example, —OP (O) (OH) ₂ or the like) or a phosphonyl group (for example, —P (O) (OH) ₂ or the like) 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 (7-1) to (7-8), 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, sulfonamide group, acyloxy group, carbamoyl group, acylamino group, cyano group or halogen atom (preferred examples are R ⁵³ and R in the general formula (5)). ⁵⁴ , and 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. Group, alkoxy group, alkoxycarbonyl group, amino group or acylamido A group.

In formulas (7-1) to (7-8), R ^{117 to} R ¹²¹ are each independently a hydrogen atom, an aliphatic group (preferably having 1 to 20 carbon atoms), or an aromatic group (preferably having a carbon number). 6 to 26), a heterocyclic group bonded to a carbon atom (preferably a 5- or 6-membered ring), preferably an aliphatic group or an aromatic group, more preferably an aliphatic group having a carboxyl group It is. 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 (7-1) to (7-8), 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 1 to 2. e7 and e8 each independently represents an integer of 0 to 4, preferably an integer of 1 to 3. e9 to e12 and e15 each independently represents an integer of 0 to 6, and e13, e14 and e16 each independently represents an integer of 0 to 4. e9 to e16 are each independently preferably an integer of 0 to 3.

When e1 to e8 is 2 or more, R ^{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 (4), 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)), acylaminooxy group (preferably an acetylene having 1 to 20 carbon atoms) Silaminooxy groups such as N-methylbenzoylaminooxy (PhC (O) N (CH ₃ ) O—), acetylaminooxy (CH ₃ C (O) NHO—) etc.)), thiocarbamate groups (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 _{(t-C 4 H 9 C} (O ...) CH = C (O-) t-C 4 H _9), dibenzoylmethane (PhC (O ...) CH = C (O-) Ph), 3- chloro-acetylacetone _{(CH 3 C (O ...)} CCl = C (O-) CH 3) , etc.), carbonamido ( Preferably, it is a carbonimine having 1 to 20 carbon atoms, such as CH ₃ N═C (CH ₃ ) O—, —OC (═NH) —C (═NH) O—, etc.), thiocarbonimine (preferably carbon atoms) A thiocarboxylic imine having 1 to 20 carbon atoms, such as CH ₃ N═C (CH ₃ ) S—, or thiourea (preferably a thiourea having 1 to 20 carbon atoms, such as NH (...) = C (S _{-) NH 2, CH 3 N} (...) = C (S-) NHCH 3, represents a ligand consisting of _{(CH 3) 2 N-C} (S ...) N (CH 3) 2 , etc.). "..." indicates a coordination bond coordinated to Mz.

  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, carboximine, thiocarbonimine, 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 (4) represents a counter ion when a counter ion is required to neutralize the charge. In general, whether a dye is a cation or an anion or has a net ionic charge depends on the metal, ligand and substituent in the dye.
The dye represented by the general formula (4) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the charge of the whole dye represented by the general formula (4) 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 (4) 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, etc.), 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 (4) 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 (4) of the present invention can be synthesized with reference to Japanese Patent Application Laid-Open No. 2001-291534 and the methods cited in the publication.
The dye composed of the compound represented by the general formula (4) 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 dye comprising at least the compound represented by the general formula (1), preferably a dye comprising the dye and a compound represented by the general formula (4) is used. Thus, high conversion efficiency can be ensured by using light having a wide range of wavelengths.

  The blending ratio of the dye consisting of the compound represented by the general formula (4) 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 both of the dye comprising the compound represented by the general formula (1) and the dye comprising the compound represented by the general formula (4) are not iodine salts, WO95 / 18456 pamphlet, JP-A-8 It is preferable to use iodine salts such as pyridinium salts, imidazolium salts and triazolium salts described in JP-A No. 259543, Electrochemistry, Vol. 65 (11), 923 (1997).
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 Nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, biscyanoethyl ether, etc.), esters (carboxylic esters, phosphate esters, phosphonates, etc.) ), Aprotic polar solvent (dimethyl sulfoxide (DMSO), sulfolane, etc.), water, hydrous electrolyte described in JP-A No. 2002-110262, JP-A No. 2000-36332, JP-A No. 2000-243134, And electrolyte solvents described in republished WO / 00-54361. These solvents may be used as a mixture of two or more.

  Further, as the electrolyte solvent, a salt that is in a liquid state at room temperature or has a melting point lower than room temperature and is electrochemically inactive 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 salt and pyridinium salt, or tetraalkylammonium Examples include salt.

  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, a compound described in Polymer Electrolyte Reviews-1 and 2 (JR MacCallum and CA Vincent co-edit, ELSEVIER APPLIED SCIENCE) is added. be able to. In this case, it is preferable to use polyacrylonitrile or polyvinylidene fluoride.

  When the electrolyte composition is gelled by adding an oil gelling agent, J.I. Chem. Soc. Japan, Ind. Chem. Soc. , P. 46779 (1943); Am. Chem. Soc. 111, p. 5542 (1989), J. MoI. Chem. Soc. , Chem. Commun. , P. 390 (1993), Angew. Chem. Int. Ed. Engl. , 35, p. 1949 (1996), Chem. Lett. , P. 885 (1996), J. MoI. 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 mass 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 photoconductivity, 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, the photosensitive layer 2 in which the dye 21 is adsorbed on the porous semiconductor fine particles 22 on the 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 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 JP-A-2002-26074 is used.
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 having the same carrier concentration due to conduction band electrons and valence band holes, the electron carrier concentration is reduced by structural defects derived from impurities. There are high n-type semiconductors. The n-type inorganic semiconductor preferably used in the present invention is TiO ₂ , TiSrO ₃ , ZnO, Nb ₂ O ₃ , SnO ₂ , WO ₃ , Si, CdS, CdSe, V ₂ O ₅ , ZnS, ZnSe, SnSe, KTaO. ₃ , FeS ₂ , PbS, InP, GaAs, CuInS ₂ , CuInSe ₂ and the like. Of these, the most preferred n-type semiconductors are TiO ₂ , ZnO, SnO ₂ , WO ₃ , and Nb ₂ O ₃ . A semiconductor material in which a plurality of these semiconductors are combined is also preferably used.

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

  As a method for producing the semiconductor fine particles, the gel-sol method described in Sakuo Sakuo's “Science of Sol-Gel Method”, Agne Jofu Co., Ltd. (1998) and the like is preferable. Also preferred is a method of producing an oxide by 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. Furthermore, as a sol-gel method, the method described in Journal of American Ceramic Society, Vol. 80 (No. 12), pages 3157-3171 (1997) such as Barbe, et al. The method described in Of 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 or SnO ₂ particles, whiskers, fibrous graphite / carbon nanotubes, zinc oxide necking binders, fibrous materials such as cellulose, metals, organic silicon, dodecylbenzenesulfonic acid, silane compounds And the like, and charge gradient binding molecules such as potential gradient dendrimers.

  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 crushing using a mill or 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% by mass or less, more preferably 3% by mass or less, and particularly preferably 1% or less. More preferably, it is 0.5 mass% or less, Most preferably, it is 0.2 mass%. 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. In addition, as an application method and a metering method can be made the same part, a wire bar method disclosed in Japanese Patent Publication No. 58-4589, a slide hopper method described in US Pat. No. 2,681,294, etc. An extrusion method, a curtain method and the like 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 for coating the semiconductor fine particles on the conductive support, (2) dry method, (3) other methods may be used in combination with the above-mentioned (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 semiconductor layer is formed on a transfer source substrate containing an inorganic salt that can be removed with ultraviolet rays and an aqueous solvent described in JP-A-2003-98777, a method of transferring via EVA described in JP-A-2002-184475. A method of removing the transfer source substrate after forming the conductive layer, transferring to the organic substrate, and the like can be mentioned.

  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.
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. 2000-11913. Examples of the mixed electrode 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. Examples of preferred tandem type configurations include those described in JP 2000-90989 A, JP 2002-90989 A, and the like.
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.

Example 1
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 T-4-I ″)
Dye T-4-I ″ was prepared according to the scheme shown below.

  0.73 g of compound 1-1 g, 0.85 g of compound 1-2, and 1 mL of triethylamine were mixed in a mixed solvent of 1-butanol 5 mL and toluene 15 mL, and the mixture was heated and stirred at 100 ° C. for 4 hours. Thereafter, the reaction solution was concentrated, and the resulting residue was purified by column chromatography to obtain 0.27 g of compound 1-3.

0.27 g of compound 1-3 and 0.25 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 110 ° 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 0.16 g of T-4-I ″. Identification was carried out by millimass, and the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1237.6902
Mass calculated value (m / z); (M + H) ⁺ : 1237.6915 (C ₈₀ H ₉₃ N ₄ O ₈ )

(2) Preparation Example 2
(Preparation of dye T-58-c)
Dye T-58-c 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 0.11 g of compound 2-4 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 5 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 T-58-c. Identification was performed by Millimas and the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1541.0017
Mass calculated value (m / z); (M + H) ⁺ : 1541.0005 (C ₁₀₂ H ₁₃₁ F ₁ N ₅ O ₆ )

(3) Preparation Example 3
(Preparation of dye T-34-i)
Compound T-34-i was prepared according to the scheme shown below.

  0.72 g of compound 3-1, 1.04 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 0.10 g of compound 3-4 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 3 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 T-34-i. When identification was performed by Millimas, the following results were obtained.
Mass measured value (m / z); (M + H) ⁺ : 1480.8891
Mass calculated value (m / z); (M + H) ⁺ : 1480.8902 (C ₉₇ H ₁₁₈ N ₅ O ₈ )

  By the same method, the pigment | dye represented by General formula (1) of this invention used for experiment was prepared. Moreover, the pigment | dye represented by General formula (4) of this invention was prepared with reference to the method quoted in the patent 4576494 and the said gazette.

(Measurement of maximum absorption wavelength of dye)
The maximum absorption wavelength of the dye used was measured. The results are shown in Table 5. 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 ethanol.

Example 2
1. Preparation of electrode 1A A 20 mm × 20 mm conductive glass plate coated with fluorine-doped tin oxide (Asahi Glass Co., Ltd., trade name: TCO glass-U, surface resistance: about 30 Ω / m ² ) was prepared. After applying an adhesive tape for spacers to both ends of the conductive layer side (a portion having a width of 3 mm from the end), the dispersion was applied onto the conductive layer using a glass rod. After application of the dispersion, the adhesive tape was peeled off and air-dried at room temperature for 1 day. Next, this semiconductor-coated glass plate was placed in an electric furnace (muffle furnace FP-32 type manufactured by Yamato Scientific Co., Ltd.) and baked at 450 ° C. for 30 minutes. The semiconductor-coated glass plate was taken out and cooled, and then immersed in an ethanol solution (concentration: 3 × 10 ⁻⁴ mol / L) of dyes shown in Table 6 below for 3 hours. The semiconductor-coated glass plate on which the dye was adsorbed was immersed in 4-tert-butylpyridine for 15 minutes, then washed with ethanol and naturally dried to obtain a titanium oxide fine particle layer (electrode 1A) on which the dye was adsorbed. The thickness of the dye-sensitized titanium oxide fine particle layer of the electrode 1A 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.

2. Production of Photoelectrochemical Battery An electrode 1A (20 mm × 20 mm) composed of a titanium oxide fine particle layer adsorbed with a dye as described above was superposed on a platinum-deposited glass of the same size. Next, using the capillary phenomenon, the electrolyte composition containing 98% by mass of the following heterocyclic quaternary salt compound and 2% by mass of iodine is infiltrated into the gap between the two glasses, so that the electrolyte is contained in the titanium oxide electrode. Introduced. As a result, as shown in FIG. 1, from a conductive support 1 made of conductive glass (with a conductive layer formed on a transparent glass substrate), a photoreceptor layer 2, a charge transfer layer 3, and platinum. A counter electrode 4 and a transparent glass substrate (not shown) are sequentially laminated, and a glass sphere having a diameter of 25 μm is almost formed in a resin composition comprising Epicoat 828 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.), a curing agent and a plastic paste. A photoelectrochemical cell sealed with a uniformly dispersed sealant was produced. However, if the electrolyte composition has a high viscosity and it is difficult to impregnate the electrolyte composition using capillary action, the electrolyte composition is heated to 50 ° C. and applied to the titanium oxide electrode. After the electrode was placed under reduced pressure and the electrolyte composition sufficiently penetrated and the air in the electrode escaped, platinum-deposited glass (counter electrode) was overlaid to produce a photoelectrochemical cell in the same manner.

3-1. Measurement of IPCE (Quantum Yield) IPCE at 400 to 900 nm of the produced photoelectrochemical cell was measured with an IPCE measuring device manufactured by Pexel. Table 6 below shows the IPCE at 850 nm of each photoelectrochemical cell.
3-2. Measurement of photoelectric conversion efficiency Light from a 500 W xenon lamp (manufactured by Ushio Inc.) passes through an AM1.5 filter (manufactured by Oriel) and a sharp cut filter (Kenko L-37, trade name) for ultraviolet light. Simulated sunlight that does not contain is generated. The intensity of this light was 70 mW / cm ² . This simulated sunlight was irradiated to the photoelectrochemical cell produced as described above at 50 ° C., and the generated electricity was measured with a current-voltage measuring device (Keutley SMU238 type). This initial battery performance result shows that conversion efficiency (3.5% or more: A, 2.5% or more and less than 3.5%: B, 2.0% or more and less than 2.5%: C, less than 2.0% : Evaluation by D), open circuit voltage and fill factor (open circuit voltage (V), fill factor: 0.6 or more: A, 0.45-0.6: B, 0.3-0.45: C, Less than 0.3: evaluated by D).
Moreover, the reduction rate of the conversion efficiency after 1000-hour dark storage at 85 degreeC and the reduction rate of the conversion efficiency after 500-hour continuous light irradiation were also measured. The results of this durability test are: A when the rate of decrease after the test is 10% or less, B when it is 10 to 25%, C when it is 25 to 40%, and D when it is 40% or more. evaluated. These results are shown in Table 6 below.
In Sample No. 1-14, S-1 was used as a dye, and in Sample No. 1-15, S-2 was used as a dye.

  From Table 6 above, all the samples using the dye of the present invention are excellent in conversion efficiency, and the conversion efficiency after dark storage and the conversion efficiency after continuous light irradiation are both low. Recognize.

Example 3
Using acetonitrile as a solvent, an electrolyte solution was prepared in which lithium iodide 0.1 mol / l, iodine 0.05 mol / l, and dimethylpropylimidazolium iodide 0.62 mol / l were dissolved. No. shown below. 1-No. 8 benzimidazole compounds were separately added and dissolved to a concentration of 0.5 mol / l.

A conductive film was formed on a glass substrate by sputtering tin oxide doped with fluorine as a transparent conductive film. Dispersion containing anatase-type titanium oxide particles on this conductive film (anatase-type titanium oxide (P-25 (trade name) manufactured by Nippon Aerosil Co., Ltd.) in 100 ml of a mixed solvent having a volume ratio of water and acetonitrile of 4: 1). 32 g of the mixture, and using a rotating / revolving mixing conditioner, uniformly dispersed and mixed to obtain a semiconductor fine particle dispersion), and then sintered at 500 ° C. to form a photosensitive layer having a thickness of 15 μm. Formed. In this photosensitive layer, the above-described 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 7 shows the open circuit voltage and photoelectric conversion efficiency obtained. The open-circuit voltage is indicated as A when the voltage is 6.3 V or more, B as 6.0 V or more and less than 6.3 V, C as 5.7 V or more and less than 6.0 V, and D as less than 5.7 V. . Conversion efficiency is A for 3.5% or more, B for 2.5% or more and less than 3.5%, C for 2.0% or more and less than 2.5%, and less than 2.0%. The thing was displayed as D.
In addition, in the following Table 7, the result of the photoelectric conversion element using the electrolyte solution which has not added the benzimidazole-type compound was also shown.

  From the results in Table 7 above, it can be seen that all the dyes of the present invention have high conversion efficiency.

Example 4
(1) Formation of first photoelectric conversion layer 4.0 g of commercially available titanium oxide particles (manufactured by Teika Co., Ltd., average particle size 30 nm) and 20 ml of diethylene glycol monomethyl ether were dispersed by a paint shaker for 6 hours using hard glass beads and oxidized. A titanium suspension was made. Next, this titanium oxide suspension was applied to a glass plate to which a tin oxide conductive layer had been previously adhered using a doctor blade, pre-dried at 100 ° C. for 30 minutes, and then in an electric furnace at 500 ° C. for 40 minutes. Firing was performed to obtain a titanium oxide film.

  Separately, Ru-1 was dissolved in ethanol.

The concentration of this dye was 3 × 10 ⁻⁴ mol. 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 the second photoelectric conversion layer 4.0 g of commercially available nickel oxide particles (Kishida Chemical, average particle size 100 nm) and 20 ml of diethylene glycol monomethyl ether were dispersed with a paint shaker using glass beads for 8 hours to suspend nickel oxide. Liquid. 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. A membrane was obtained.

Separately from this, the dye of the present invention and the comparative dye S-1 were dissolved in dimethyl sulfoxide, respectively.
The concentration of this dye was 0.5 × 10 ⁻⁴ mol. 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. A liquid electrolyte was put between these 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 C) of the present invention. In addition, the liquid electrolyte is a mixed solvent of acetonitrile / ethylene carbonate (volume ratio is 1: 4), tetrapropylammonium iodide and iodine, with respective concentrations of 0.46 mol / l and 0.06 mol / l. What was melt | dissolved so that it might become 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. The conversion efficiency is A for 6.5% or more, B for 6.0% or more and less than 6.5%, C for 5.0% or more and less than 6.0%, and less than 5.0%. The results are shown in Table 8 as D.

  From Table 8 above, it can be seen that all of the dyes of the present invention are excellent in photoelectric conversion efficiency and are effective even in this system.

Example 5
(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. Formed body. Next, a carbon electrode was formed as a counter electrode.
Next, the glass substrate on which the above-described insulating porous body was formed was immersed in an ethanol solution of a sensitizing dye (mixed or single) described in Table 9 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 that does not contain ultraviolet rays was generated by passing light from a 500 W xenon lamp (manufactured by Ushio Electric) through an AM1.5G filter (manufactured by Oriel) and a sharp cut filter (KenkoL-42, trade name). The intensity of this light was 89 mW / cm ² . The produced photoelectric conversion element was irradiated with this light, and the generated electricity was measured with a current-voltage measuring device (Caseley 238 type, trade name). The results of measuring the conversion efficiency of the photoelectrochemical cell thus obtained are shown in Table 9 below. As a result, conversion efficiency of 7.5% or more is A, 7.2% or more and less than 7.5% is B, 6.9% or more and less than 7.2% is C, 6.9% Less than that was evaluated as D.

  As is clear from Table 9 above, all the samples (electrochemical cells) prepared using the dye of the present invention showed a high conversion efficiency of 7.5% or more. On the other hand, all of the samples of the comparative examples had an insufficient conversion efficiency of less than 7.2%.

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 (9)

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

[In the general formula (1), Q represents a benzene ring or a naphthalene ring ^group, X 1, ^{X 2} each independently represent a sulfur atom, an oxygen atom or ^{C (R a) R b,} . Here, R ^a and R ^b each independently represents 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 alkyl group or an aromatic group.
P ¹ and P ² are each independently a nonmetallic atom group necessary for forming a polymethine dye represented by P ¹¹ of the following general formula (2-1) or P ¹² of the following general formula (2-2) Indicates.
W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formulas (2-1) and (2-2), V represents a substituent.
One of V of P ¹ and P ² in the general formula (1) (referred to as Va) is an acidic group or a group having an acidic group, and the Va is only ^one of P ¹ and P ^2. It has. R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic). R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} and R ^{3 ′} each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded via a carbon atom. One or more of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va is a substituent having a positive σp value in Hammett's rule or The σp value in the Hammett rule is a group having a positive substituent.
Y and Y ′ each independently represent a sulfur atom, N (R ^d ) or C (R ⁶ ) (R ^{6 ′} ). R ⁶ and R ^{6 ′} represent a substituent. R ^d represents an alkyl group. n1 and n1 ′ represent an integer of 1 or more, and n2 represents an integer of 0 or more. The carbon-carbon double bond may be either E-type or Z-type. When n1 and n1 ′ are integers of 2 or more, a plurality of Vs may be the same or different, and a plurality of Vs may be bonded to each other to form a ring. ] A group of non-metallic atoms necessary for forming a polymethine dye in which the acidic group or a group having an acidic group (Va) and a substituent having a positive σp value in Hammett's rule or a group having the substituent are bonded, The photoelectric conversion element according to claim 1, wherein the photoelectric conversion element is one of P ¹¹ and P ¹² .   The photoelectric conversion element according to claim 1 or 2, wherein the n2 is 0 or 1. 4. The exo double bond portion of the methenyl group of R ^{5 ′} is represented by the following general formula (3-1) or (3-2). Photoelectric conversion element.

[In General Formula (3-2), R ⁷ represents a hydrogen atom, an alkyl group, or an alkali metal. The carbon-carbon double bond may be either E-type or Z-type. ] The photoelectric conversion element according to claim 1, wherein R ^{5 ′} is a carbonyl group.   The photoelectric conversion according to claim 1, wherein Va is a 5-carboxy group, a 5-sulfonic acid group, a 5-phosphonyl group, a 5-phosphoryl group, or a salt thereof. element. It said photosensitive layer is a photoelectric conversion element according to any one of claims 1 to 6, further comprising a dye comprising a compound represented by the following general formula (4).
Mz (LL ¹ ) _m1 (LL ² ) _m2 (X) _m3 · CI General formula (4)
[In General Formula (4), Mz represents Ru, Os, Zn or Cu , LL ¹ represents a bidentate or tridentate ligand represented by the following General Formula (5), and LL ² represents the following General The bidentate or tridentate ligand represented by Formula (6) is represented. X is an acyloxy group, an acylthio group, a thioacyloxy group, a thioacylthio group, an acylaminooxy group, a thiocarbamate group, a dithiocarbamate group, a thiocarbonate group, a dithiocarbonate group, a trithiocarbonate group, an acyl group, a thiocyanate group, A monodentate or bidentate ligand coordinated by a group selected from the group consisting of an isothiocyanate group, a cyanate group, an isocyanate group, a cyano group, an alkylthio group, an arylthio group, an alkoxy group and an aryloxy group, or a halogen atom Represents a monodentate or bidentate ligand selected from the group consisting of carbonyl, dialkyl ketone, 1,3-diketone, carboximine, thiocarbonimine 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 required to neutralize the charge in the general formula (4). ]

[In General Formula (5), R ⁵¹ and R ⁵² each independently represent an acidic group or a group having an acidic group. R ⁵³ and R ⁵⁴ each independently represent a substituent, and R ⁵⁵ and R ⁵⁶ each independently represent an alkyl group, an aryl group or a heterocyclic group. d1 and d2 each represent an integer of 0 to 5. L ¹ and L ² each independently represents a conjugated chain composed of an ethenylene group and / or an 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. When b1 is 2 or more, R ⁵³ may be the same or different, and R ⁵³ may be linked to each other to form a ring. In the above, R ⁵⁴ may be the same or different, and R ⁵⁴ may be linked to each other to form a ring. When both b1 and b2 are 1 or more, R ⁵³ and R ⁵⁴ may be linked to form a ring. d3 represents 0 or 1. ]

[In General formula (6), Za, Zb, and Zc represent the nonmetallic atom group which can form a 5-membered ring or a 6-membered ring each independently, and c represents 0 or 1. However, at least one of the rings formed by Za, Zb and Zc has an acidic group. ]
  A photoelectrochemical cell comprising the photoelectric conversion device according to claim 1. A dye comprising at least a compound represented by the following general formula (1).

[In General Formula (1), Q represents a benzene ring group or a naphthalene group, and X ¹ and X ² each independently represent a sulfur atom, an oxygen atom, or C (R ^a ) R ^b . Here, R ^a and R ^b each independently represents 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 alkyl group or an aromatic group.
P ¹ and P ² are each independently a nonmetallic atom group necessary for forming a polymethine dye represented by P ¹¹ of the following general formula (2-1) or P ¹² of the following general formula (2-2) Indicates.
W ¹ represents a counter ion as necessary to neutralize the charge. ]

[In General Formulas (2-1) and (2-2), V represents a substituent.
One of V of P ¹ and P ² in the general formula (1) (referred to as Va) is an acidic group or a group having an acidic group, and the Va is only ^one of P ¹ and P ^2. It has. R ^{5 ′} represents a methenyl group bonded to an atom or a substituent with a double bond to exo (extracyclic). R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} and R ^{3 ′} each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group bonded via a carbon atom. One or more of V, R ¹ , R ² , R ³ , R ⁴ , R ^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{5 ′} other than Va is a substituent having a positive σp value in Hammett's rule or The σp value in the Hammett rule is a group having a positive substituent.
Y and Y ′ each independently represent a sulfur atom, N (R ^d ) or C (R ⁶ ) (R ^{6 ′} ). R ⁶ and R ^{6 ′} represent a substituent. R ^d represents an alkyl group. n1 and n1 ′ represent an integer of 1 or more, and n2 represents an integer of 0 or more. The carbon-carbon double bond may be either E-type or Z-type. When n1 and n1 ′ are integers of 2 or more, a plurality of Vs may be the same or different, and a plurality of Vs may be bonded to each other to form a ring. ]

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