JP2015167217A - Photoelectric conversion element, dye-sensitized solar cell and metal complex dye used therefor - Google Patents

Abstract

The present invention provides a photoelectric conversion element, a dye-sensitized solar cell, and a metal complex dye that have both high photoelectric conversion efficiency and high water resistance. A photoelectric conversion element having a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer body layer containing an electrolyte, and a counter electrode, wherein the photoreceptor layer is a metal complex dye represented by the formula (I) Has semiconductor fine particles supported thereon. A hue sensitizer melt battery comprising this photoelectric conversion element. M1 (LA) (LD) Z1 Formula (I). (M1 is a metal atom, LA is a 5-membered or 6-membered heterocyclic ring containing nitrogen, preferably a tridentate aromatic ring, and LD is a nitrogen-containing aromatic 5-membered ring and 6-membered ring. A bidentate ligand consisting of a member ring, Z1 represents a monodentate ligand.) [Selection] None

Description

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

  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. A solar cell using non-depleting solar energy does not require fuel, and its full-scale practical use is expected as an 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 naturally has limitations in throughput and molecular modification.

  Therefore, research on dye-sensitized solar cells has been vigorously conducted. In particular, it was the research results of Graetzel and others at the Swiss Lausanne University of Technology. They adopted a structure in which a dye composed of a ruthenium complex was fixed on the surface of a porous titanium oxide thin film, realizing photoelectric conversion efficiency comparable to that of amorphous silicon. As a result, dye-sensitized solar cells have attracted attention from researchers all over 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. Furthermore, the development of ruthenium complex-based sensitizing dyes continues to improve the photoelectric conversion efficiency (see Patent Document 2).

US Pat. No. 5,463,057 US Patent Application Publication No. 2010/0258175

A terpyridyl pigment N749 is often used as a pigment capable of photoelectric conversion up to a long wavelength, but its water resistance is insufficient. Although water is considered to desorb the dye adsorbed on the semiconductor fine particles, water enters the cell mainly with time from the outside of the cell. Sealing technology has also been developed and has been improved since before, but it is still insufficient, and it is difficult to completely prevent water from entering. Therefore, it is necessary for the dye itself to have a structure capable of suppressing the approach of water, and it has been a problem to achieve both high photoelectric conversion efficiency and high water resistance.
An object of the present invention is to provide a photoelectric conversion element, a dye-sensitized solar cell, and a metal complex dye used in them, which use a metal complex dye having a specific structure and achieve both high photoelectric conversion efficiency and high water resistance. To do.

The above problem has been solved by the following means.
<1> A photoelectric conversion element having a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer body layer containing an electrolyte, and a counter electrode, wherein the photoreceptor layer is represented by the following formula (I) A photoelectric conversion element having semiconductor fine particles on which is supported.

M ¹ (LA) (LD) Z Formula ¹ (I)

In the formula (I), M ¹ represents a metal atom and Z ¹ represents a monodentate ligand. LA represents a tridentate ligand represented by the following formula (AL-1). LD represents a bidentate ligand represented by the following formula (DL-1).

In the formula (AL-1), Za, Zb and Zc each independently represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.
In the formula (DL-1), E represents a group represented by any of the following formulas (E-1) to (E-6). X represents an oxygen atom, a sulfur atom, a selenium atom, N (Ra), C (Rb) ₂ or Si (Rb) ₂ . Here, Ra and Rb each independently represents a hydrogen atom, an alkyl group or an aryl group. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group.

In formulas (E-1) to (E-5), R represents a halogen atom or an alkyl group that may be substituted with a halogen atom. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
<2> The photoelectric conversion element according to <1>, wherein M ¹ is Ru.
<3> The photoelectric conversion element according to <1> or <2>, in which LA is represented by the following formula (AL-2).

In Formula (AL-2), R ^{A1 to} R ^A3 each independently represent a hydrogen atom, an alkyl group, an alkynyl group, a heteroaryl group, an aryl group, or an acidic group. a1 and a3 each independently represent an integer of 0 to 4, and a2 represents an integer of 0 to 3. However, any of a1 to a3 is an integer of 1 or more, and at least one of R ^{A1 to} R ^A3 is an acidic group, and the acidic group is bonded to at least a pyridine ring.
<4> The photoelectric conversion element according to any one of <1> to <3>, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).

In the formula (II), R ¹⁰ represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.
<5> The photoelectric conversion element according to any one of <1> to <4>, wherein the metal complex dye represented by the formula (I) is represented by the following formula (III).

In the formula (III), Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.
<6> The photoelectric conversion element according to any one of <1> to <5>, wherein a plurality of dyes are supported on the semiconductor fine particles.
<7> Among the metal complex dyes supported on the semiconductor fine particles, at least one of the dyes other than the metal complex dye represented by the formula (I) has a maximum absorption wavelength in a tetrabutylammonium hydroxide methanol solution of 590 nm. The photoelectric conversion element according to any one of <1> to <6>.
<8> The photoelectric conversion device according to any one of <1> to <7>, wherein a semiconductor adsorbent further supports a coadsorbent having one or more acidic groups.
<9> The photoelectric conversion element according to <8>, wherein the coadsorbent is represented by the following formula (CA).

In the formula (CA), R ^C1 represents a substituent having an acidic group. R ^C2 represents a substituent. lc represents an integer of 0 or more.
<10> A dye-sensitized solar cell including the photoelectric conversion element according to any one of <1> to <9>.
<11> A metal complex dye represented by the following formula (I).

M ¹ (LA) (LD) Z Formula ¹ (I)

In the formula (I), M ¹ represents a metal atom and Z ¹ represents a monodentate ligand. LA represents a tridentate ligand represented by the following formula (AL-1). LD represents a bidentate ligand represented by the following formula (DL-1).

In the formula (AL-1), Za, Zb and Zc each independently represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.
In the formula (DL-1), E represents a group represented by any of the following formulas (E-1) to (E-6). X represents an oxygen atom, a sulfur atom, a selenium atom, N (Ra), C (Rb) ₂ or Si (Rb) ₂ . Here, Ra and Rb each independently represents a hydrogen atom, an alkyl group or an aryl group. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group.

In formulas (E-1) to (E-5), R represents a halogen atom or an alkyl group that may be substituted with a halogen atom. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
<12> The metal complex dye according to <11>, wherein M ¹ is Ru.
<13> The metal complex dye according to <11> or <12>, in which LA is represented by the following formula (AL-2).

In Formula (AL-2), R ^{A1 to} R ^A3 each independently represent a hydrogen atom, an alkyl group, an alkynyl group, a heteroaryl group, an aryl group, or an acidic group. a1 and a3 each independently represent an integer of 0 to 4, and a2 represents an integer of 0 to 3. However, any of a1 to a3 is an integer of 1 or more, and at least one of R ^{A1 to} R ^A3 is an acidic group, and the acidic group is bonded to at least a pyridine ring.
<14> The metal complex dye according to any one of <11> to <13>, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).

In the formula (II), R ¹⁰ represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.
<15> The metal complex dye according to any one of <11> to <14>, wherein the metal complex dye represented by the formula (I) is represented by the following formula (III).

In the formula (III), Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.

  In this specification, an aromatic ring is used to mean an aromatic ring and a heterocycle (aromatic heterocycle and non-aromatic heterocycle), and may be monocyclic or multicyclic. The carbon-carbon double bond may be any of E type and Z type in the molecule. When there are a plurality of substituents indicated by a specific symbol, or when a plurality of substituents and ligands (including the number of substituents) are specified simultaneously or alternatively, each substituent or ligand, etc. May be the same as or different from each other. Further, when a plurality of substituents or ligands are close to each other, they may be connected to each other or condensed to form a ring. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The photoelectric conversion element, the dye-sensitized solar cell of the present invention, and the metal complex dye used therefor can achieve both high photoelectric conversion efficiency and high water resistance.

It is sectional drawing shown typically about one embodiment of the photoelectric conversion element of this invention. 2 is a cross-sectional view schematically showing a dye-sensitized solar cell produced in Example 1. FIG. 3 is a cross-sectional view schematically showing a dye-sensitized solar cell produced in Example 2. FIG. It is sectional drawing which showed typically the modification of the photoelectric conversion element shown in FIG. 1 in the enlarged part (circle) about the dye-sensitized solar cell produced in Example 3. FIG.

The metal complex dye of the present invention has a structure in which a tridentate ligand containing a nitrogen atom and a bidentate ligand containing a nitrogen atom are coordinated with a central metal. Even in a long wavelength region exceeding 700 nm, high IPCE (incident photo-to-current efficiency) was exhibited, ε (molar extinction coefficient) was high, and high photoelectric conversion efficiency and high water resistance were realized.
This reason includes unclear points, but can be explained as follows, including estimation. The metal complex dye having a specific structure containing the heterocycle-containing ligand of the present invention contributes to the expansion of the conjugated system and the improvement of donor properties. This seems to improve ε on the long wavelength side. In particular, the expansion of the conjugated system by introduction of a vinyl group and the improvement of donor properties by introduction of an ethylenedioxy group have the above effects. Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.

<< Photoelectric conversion element and dye-sensitized solar cell >>
For example, as shown in FIG. 1, the photoelectric conversion element of the present invention includes a conductive support 1, a photoreceptor layer 2 including semiconductor fine particles 22 sensitized by supporting a dye (metal complex dye) 21, It consists of a charge transfer layer 3 and a counter electrode 4 which are hole transport layers. The conductive support 1 provided with the photoreceptor layer 2 functions as a working electrode in the photoelectric conversion element 10. In the present embodiment, the photoelectric conversion element 10 is shown as a system 100 using a dye-sensitized solar cell that can be used for a battery application in which the operating means M (electric motor) works by the external circuit 6.

In the present embodiment, the light receiving electrode 5 includes a conductive support 1 and a photoreceptor layer 2 including semiconductor fine particles 22 on which a dye (metal complex dye) 21 is adsorbed. The photoreceptor layer 2 is designed according to the purpose, and may be a single layer structure or a multilayer structure. The dye (metal complex dye) 21 in one layer of the photoreceptor layer may be one kind or a mixture of many kinds, and at least one of them is the metal complex dye of the present invention described later. The light incident on the photoreceptor layer 2 excites the dye (metal complex dye) 21. The excited dye has high energy electrons, and the electrons are transferred from the dye (metal complex dye) 21 to the conduction band of the semiconductor fine particles 22 and reach the conductive support 1 by diffusion. At this time, the dye (metal complex dye) 21 is an oxidant, but the electrons on the electrode work in the external circuit 6 and pass through the counter electrode 4 so that the oxidant of the dye (metal complex dye) 21 and By returning to the photoreceptor layer 2 where the electrolyte is present, it functions as a solar cell.
Note that the upper and lower sides of the photoelectric conversion element do not need to be defined in particular. However, in this specification, based on what is shown in the specification, the counter electrode 4 side is the upper (top) direction, and the conductivity is the light receiving side. The side of the support 1 is the lower (bottom) direction.

In the present invention, the material used for the photoelectric conversion element or the dye-sensitized solar cell and the method for producing each member may employ a production method usually used in the photoelectric conversion element or the dye-sensitized solar cell. US Pat. No. 4,927,721, US Pat. No. 4,684,537, US Pat. No. 5,084,365, US Pat. No. 5,350,644, US Pat. No. 5,463,057, US Pat. No. 5,525,440, JP-A-7-249790, JP-A-2004-220974, and JP-A-2008-135197.
Hereinafter, an outline of the main members will be described.

<Photoreceptor layer>
The photoreceptor layer is a layer containing semiconductor fine particles containing an electrolyte described later and carrying a metal complex dye of the present invention described below. At this time, a part of the metal complex dye dissociated in the electrolyte may be present.

<< metal complex dye >>
The metal complex dye of the present invention is represented by the following formula (I).

M ¹ (LA) (LD) Z Formula ¹ (I)

<M ¹ >
M ¹ represents a metal atom. M ¹ is preferably a metal capable of six coordination, more preferably Ru, Fe, Os, Cu, W, Cr, Mo, Ni, Pd, Pt, Co, Ir, Rh, Re, Mn or Zn. is there. More preferred is Ru, Os, Zn, Cu, Co, Ir or Rh, particularly preferred is Ru or Os, and most preferred is Ru.

<LA>
LA is represented by the following formula (AL-1).

・ Za, Zb, Zc
In the formula (AL-1), Za, Zb and Zc each independently represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.

The 5-membered or 6-membered ring formed by Za, Zb and Zc may be substituted or unsubstituted, and may be monocyclic or condensed. Za, Zb and Zc are preferably atoms in which the ring atoms are selected from a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom and a phosphorus atom, and the atom includes a hydrogen atom and a substituent including a halogen atom. The group may be substituted. Examples of the substituent include the substituent T described later.
The 5- or 6-membered condensed ring structure includes a structure in which a benzene ring is condensed to a 5-membered or 6-membered ring, and specifically includes benzimidazole.
The ring formed by Za, Zb and Zc is more preferably 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.

・ Acid group Ac
In the present invention, the acidic group is a substituent having a dissociative proton, and examples thereof include a carboxy group, a phosphonyl group, a phosphoryl group, a sulfo group, a boric acid group, and a group having any one of these, A carboxy group, a phosphonyl group or a group having this is preferred. A carboxy group is preferable from the viewpoint of electron injection, and a phosphonyl group is preferable from the viewpoint of adsorption power. Further, the acidic group may take a form of releasing a proton and dissociating, or may be a salt. When it becomes a salt, the counter ion is not particularly limited, and examples thereof include positive ions in the following counter ion CI. In the present invention, the acidic group may be a group bonded through a linking group, such as a 2-carboxyvinyl group, a 2,2-dicarboxyvinyl group, a 2-cyano-2-carboxyvinyl group, a carboxyphenyl group, A carboxythienyl group etc. can be mentioned as a preferable acidic group. In addition, the acidic group mentioned here and its preferable range may be called acidic group Ac.

  LA is preferably a ligand represented by the following formula (AL-2).

・ R ^A1 , R ^A2 , R ^A3
R ^{A1 to} R ^A3 each independently represent a hydrogen atom, an alkyl group, an alkynyl group, a heteroaryl group, an aryl group, or an acidic group. The alkyl group, the alkynyl group, the heteroaryl group, and the aryl group are preferably the groups listed for the substituent T described later. The heteroaryl group is preferably a 5- or 6-membered ring and a heteroatom selected from an oxygen atom, a sulfur atom, a nitrogen atom, and a selenium atom, and a heterocycle containing a benzene ring or a heteroaryl ring. It may be condensed with. The acidic group is preferably a group listed as the acidic group Ac.

・ A1, a2, a3
a1 and a3 each independently represent an integer of 0 to 4, and a2 represents an integer of 0 to 3. However, any of a1 to a3 is an integer of 1 or more.
At least two of a1 to a3 are preferably an integer of 1 or more (preferably 1), and three is more preferably an integer of 1 or more (preferably 1).

Note that at least one of R ^{A1 to} R ^A3 is an acidic group, and the acidic group is bonded to at least a pyridine ring. That is, any of the three pyridine rings in the above formula (AL-2) has at least one acidic group.

  LA is more preferably a ligand represented by the following formula (AL-3).

In formula ^{(AL-3), R A1} ~R A3 has the same meaning as ^R A1 ^{to R A3} in the formula (AL-2), and the preferred range is also the same. However, at least one of R ^{A1 to} R ^A3 is an acidic group.
At least two of R ^{A1 to} R ^A3 are preferably acidic groups, and more preferably three are acidic groups.

  Although the following is mentioned as a specific example of LA, this invention is limited to this and is not interpreted.

<LD>
LD is represented by the following formula (DL-1).

・ E
E represents a group represented by any of the following formulas (E-1) to (E-6).

In formulas (E-1) to (E-5), R represents a halogen atom or an alkyl group that may be substituted with a halogen atom. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
Examples of the halogen atom and the alkyl group that may be substituted with the halogen atom include the substituent T described later. Here, the alkyl group substituted with a halogen atom is preferably an alkyl group substituted with a fluorine atom. Further, the halogen atom substitution is preferably a perhalogenated alkyl group, more preferably a perfluoroalkyl group. Of these, perfluoromethyl is preferred.

m represents an integer of 0 or more. The upper limit of m is the number that can be substituted in each formula. For example, it is 3 in the formula (E-1). m is preferably 0 or 1, and more preferably 1.
Here, when several R exists, these may mutually be same or different.

  Of formulas (E-1) to (E-6), formulas (E-1), (E-2), and (E-4) to (E-6) are preferred, and formulas (E-1) and (E-6) are preferred. E-2), (E-4), and (E-5) are more preferable, and formulas (E-2), (E-4), and (E-5) are more preferable, and (E-2), (E −5) is particularly preferred, and formula (E-2) is most preferred.

X represents an oxygen atom, a sulfur atom, a selenium atom, N (Ra), C (Rb) ₂ or Si (Rb) ₂ . Here, Ra and Rb each independently represents a hydrogen atom, an alkyl group or an aryl group. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. The sum of na and nb is preferably 2 or more from the viewpoint of increasing ε. The preferred na is 1.
X is preferably an oxygen atom, a sulfur atom, N (Ra), C (Rb) ₂ or Si (Rb) _2, more preferably an oxygen atom, a sulfur atom, N (Ra) or C (Rb) ₂ , and N ( Ra) or a sulfur atom is more preferred, and a sulfur atom is particularly preferred.

Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group.
Rc is presumed to suppress dye desorption from the surface of the semiconductor fine particles due to water, which contributes to suppressing the approach of water due to its hydrophobicity and space volume, and causes a decrease in battery performance.
From the viewpoint of suppressing the proximity of water that causes desorption of the dye, preferably an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group, more preferably an alkyl group, an alkylthio group, an alkenyl group or an alkynyl group, more preferably An alkyl group or an alkylthio group, particularly preferably an alkyl group. This is because these are highly hydrophobic and have a high degree of freedom.

  The number of nucleus atoms of the alkyl group, alkenyl group, alkynyl group and alkylthio group is preferably 1 to 15, more preferably 2 to 10, particularly preferably 3 to 8, and most preferably 4 to 6. The amino group is preferably a monosubstituted amino group, a disubstituted amino group, and more preferably a disubstituted amino group from the viewpoint of inhibiting water access. The disubstituted amino group is preferably a dialkylamino group, an amino group substituted with one alkyl group and one aryl group, and more preferably a dialkylamino group from the viewpoint of suppressing water access. From the viewpoint of oxidation resistance of the amino group itself, an amino group substituted with two aryl groups is preferred. The number of nucleus atoms of the amino group is preferably 3 to 25, more preferably 5 to 21, particularly preferably 7 to 17, and most preferably 9 to 15.

Further, from the viewpoint of improving ε by conjugation extension, an alkenyl group or an alkynyl group is preferable, and an alkynyl group is more preferable.
On the other hand, from the viewpoint of improving ε by improving donor properties (electron donating properties), an alkyl group, an alkylthio group and an amino group are preferred, and an amino group is more preferred.
Since the amino group is protonated under acidic conditions, it becomes highly polar in that case, which is not preferable, but the electrolyte solution of ordinary dye-sensitized solar cells contains excessive basic compounds and cannot be acidic conditions. .

  Since a rigid structure such as an aryl group as Rc has a relatively low degree of freedom, from the viewpoint of water resistance, in the present invention, Rc is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. . In addition, as a substituent substituted by Rc, a hydrophobic group is preferable because it is difficult for water molecules to approach. For this reason, an alkyl group, an alkenyl group, an alkynyl group, and an alkylthio group are preferably unsubstituted without any substituent. Similarly, in the group directly substituted on the nitrogen atom of the amino group, for example, an alkylamino group, the alkyl group is preferably unsubstituted.

  A group consisting of a combination of na repeating ethynyl group and nb repeating ethylenedioxy-containing X-substituted 5-membered heteroaryl ring group is preferably at the 4-position of the pyridine ring substituted with E.

  Specific examples of LD are shown below, but the present invention is not construed as being limited to these examples.

<Ligand Z ¹ >
Z ¹ represents a monodentate ligand. Z ¹ is, for example, acyloxy group, acylthio group, thioacyloxy group, thioacylthio group, acylaminooxy group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, trithiocarbonate group, acyl group , Thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, selenate group, isoselenate group, isoselenocyanate group, cyano group, alkylthio group, arylthio group, alkoxy group and aryloxy group. And a monodentate ligand selected from the group consisting of a halogen atom, a phosphine ligand, carbonyl, dialkyl ketone, carbonamide, thiocarbonamide and thiourea.

Z ¹ is preferably an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. Note ligand Z ¹ is the alkyl moiety, alkenyl part, alkynyl site, if it contains alkylene moiety such as, they may be linear or branched, may be either unsubstituted substituted. Further, when an aryl moiety, a heterocyclic moiety, a cycloalkyl moiety and the like are included, they may be substituted or unsubstituted, and may be monocyclic or condensed.

  In the present invention, the metal complex dye represented by the formula (I) is preferably a metal complex dye represented by the following formula (II), and more preferably a metal complex dye represented by the following formula (III).

In the formula (II), Rc, na and nb are synonymous with Rc, na and nb in the formula (DL-1), and preferred ranges are also the same. R ^A1 to R ^A3 has the same meaning as ^R A1 ^{to R A3} in Formula (AL-3), and the preferred range is also the same. R ¹⁰ represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.
R ¹⁰ is preferably an alkyl group which may be substituted with a halogen atom, and more preferably an alkyl group substituted with a fluorine atom.

In the formula (III), Rc has the same meaning as Rc in the formula (DL-1), and the preferred range is also the same. R ^A1 to R ^A3 has the same meaning as ^R A1 ^{to R A3} in Formula (AL-3), and the preferred range is also the same. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.

Specific examples of the metal complex dye represented by the formula (I) of the present invention are shown below, but the present invention is not limited thereto.
Note that the ligand is coordinated to a metal atom, that is, an atom coordinated by an anion is represented by an anion, but it is not necessarily coordinated by an anion.
The metal complex dye omits a counter ion, but does not need a counter ion but can hold an arbitrary counter ion. Examples of the counter ion include CI in formula (Z) described later.

  The metal complex dye represented by the formula (I) of the present invention is described in Chem. Commun. , 2009, 5844-5846.

[Dye used in combination with the metal complex dye of the present invention]
When using the metal complex dye of this invention for the below-mentioned photoelectric conversion element, it may be used independently or may be used together with another dye. Among these dyes, at least one dye (a dye other than the metal complex dye represented by the formula (I) of the present invention) has a maximum absorption wavelength on the longest wavelength side of 0.34 mmol / L tetrabutylammonium hydroxide. It is preferable that it is 590 nm or more in a methanol solution.

  By combining with a dye that efficiently performs photoelectric conversion on the longer wavelength side than the metal complex dye represented by the formula (I) of the present invention, sunlight can be efficiently photoelectrically converted. The dye to be combined is preferably a porphyrin dye, squarylium dye, phthalocyanine dye, more preferably a porphyrin dye or squarylium dye, and particularly preferably a squarylium dye. Among the porphyrin dyes, a binuclear complex is preferable, and among the squarylium dyes, a bis-squarylium dye having two squarylium skeletons is preferable.

(Metal complex dye represented by formula (Z))
As the dye other than the metal complex dye described above, a metal complex dye represented by the following formula (Z) is preferable. By using together with the metal complex dye represented by the formula (I) of the present invention, it is possible to control the mutual adsorption state and achieve higher photoelectric conversion efficiency and durability than each other.

M ^Z (LD ^Z ) _zd (LA ^Z ) _za (Y ^Z ) _zy · CI Formula (Z)

* Metal atom M ^z
M ^Z has the same meaning as M ¹ in formula (I).

* LD ^Z
LD ^Z represents a bidentate ligand represented by the following formula (DL-Z).

・ R ^Z1
R ^Z1 represents an alkyl group, an aryl group, or a heteroaryl group.
The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, such as methyl, t-butyl, n-hexyl, 2-ethylhexyl, hexadecyl, octadecyl and the like.
The aryl group is preferably an aryl group having 6 to 30 carbon atoms, such as phenyl, substituted phenyl, naphthyl, substituted naphthyl and the like.
The heteroaryl group is preferably a heteroaryl group having 1 to 30 carbon atoms, such as 2-thienyl, 2-pyrrolyl, 2-imidazolyl, 1-imidazolyl, 4-pyridyl, 3-indolyl and two or more thereof. These are condensed or connected in combination.
More preferably, it is a heteroaryl group having 1 to 3 electron donating groups, and more preferably, thienyl and thienyl are condensed or linked by two or more.
Here, the electron donating group is preferably an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an amino group, an acylamino group or a hydroxy group, and an alkyl group, an alkoxy group, an amino group or a hydroxy group. Are more preferable, and an alkyl group is particularly preferable.

・ L ^Z1 , L ^Z2
L ^Z1 and L ^Z2 each independently represent a conjugated chain of π electrons, and a conjugated chain capable of π conjugation up to an atom where R π of the pyridine ring of the ligand skeleton and R ^Z1 are bonded. Mention may be made of a conjugated chain comprising at least one of an arylene group, a heteroarylene group, an ethenylene group and an ethynylene group. The conjugated chain (arylene group, heteroarylene group) may be unsubstituted or may have a substituent. When the ethenylene group has a substituent, the substituent is preferably an alkyl group, and more preferably methyl. L ^Z1 and L ^Z2 are each independently preferably a conjugated chain having 2 to 6 carbon atoms, more preferably thiophenediyl, ethenylene, butadienylene, ethynylene, butadienylene, methylethenylene, or dimethylethenylene, particularly preferably ethenylene or butadienylene. Ethenylene is most preferred. L ^Z1 and L ^Z2 may be the same or different, but are preferably the same. In addition, when a conjugated chain contains a carbon-carbon double bond, each double bond may be E-type or Z-type, or a mixture thereof.

・ Z0, z1, z2, z11, z12, z13, z14
z0 and z1 each independently represent an integer of 0 to 5, an integer of 0 to 3 is preferred, and an integer of 0 to 2 is more preferred. z2 represents 0 or 1.
z11 and z12 each independently represents an integer of 0 to 3. However, the sum of z11 and z12 is 1 or more, and when z11 and z12 are each 2 or more, a plurality of Ac may be the same or different from each other. A is the sum of z11 and z12 is 1 or more, when the ligand LD ^Z is having at least one acidic group, zd in the formula (DL-Z) is preferably 2 or 3, 2 is more preferable. z11 is preferably 0 or 1, and z12 is preferably an integer of 0 to 2.
In particular, when z2 is 0, z12 is preferably 1 or 2, and when z2 is 1, z12 is preferably 0 or 1. The total sum of z11 and z12 is preferably an integer of 0-2.
z13 and z14 are each independently an integer of 0 to 3, ^{R Z2} where z13 and z14 there are a plurality of two or more time in each may be the same or different from each other. z13 and z14 are preferably integers of 0 to 2.

・ Ac
Ac represents an acidic group. When a plurality of Ac are present, these may be the same as or different from each other. Ac is synonymous with that defined in formula (I), and the preferred range is also the same. Ac may be substituted on the pyridine ring or any atom of the substituent.

・ R ^Z2
R ^Z2 represents a substituent, and when a plurality of R ^Z2 are present, these may be the same as or different from each other, and may be bonded to each other to form a ring.
^Examples of the substituent of R ^Z2 include the substituent of the substituent T described later. R ^Z2 is preferably an alkyl group, alkenyl group, cycloalkyl group, aryl group, heterocyclic group, alkoxy group, aryloxy group, alkoxycarbonyl group, amino group, acyl group, sulfonamido group, acyloxy group, carbamoyl group, An acylamino group, a cyano group or a halogen atom, more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group or a halogen atom, particularly preferably an alkyl group. , An alkenyl group, an alkoxy group, an alkoxycarbonyl group, an amino group or an acylamino group.

・ Zd
zd represents an integer of 0 to 3, zd is preferably 0 to 2, and more preferably 0 or 1. When zd is 2 or more, a plurality of LD ^Z may be the same or different from each other.

Ligand LD ^Z in formula (Z) is preferably one represented by the following general formula (DLZ-1) ~ (DLZ -3).

^{Wherein, Ac, R Z2, z11~z14,} z2 is ^Ac in Formula (DL-Z), R Z2 , z11~z14, is synonymous with z2. R ^Z3 represents a substituent, and R ^Z4 and R ^Z5 each independently represent a hydrogen atom or a substituent. z15 represents the integer of 0-4.

* LA ^Z
LA ^Z represents bidentate or tridentate ligand represented by the following formula (AL-Z).

  In the formula (AL-Z), Zd, Ze, and Zf represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. h represents 0 or 1; However, at least one of the rings formed by Zd, Ze, and Zf has an acidic group.

・ Za
za represents an integer of 1 to 3, and 1 or 2 is preferable. When za is 2 or more, a plurality of LA ^Z may be the same or different from each other.

・ Zd, Ze, Zf
Zd, Ze and Zf are synonymous with Za, Zb and Zc in the formula (I).

・ H
h represents 0 or 1;

Ligands LA ^Z is preferably a ligand represented by any of the following formulas (ALZ-1) ~ (ALZ -8), formula (ALZ-1), (ALZ -2), (ALZ-4 ), (ALZ-6), or (ALZ-7) is more preferred, and the coordination is represented by the formula (ALZ-1), (ALZ-2), or (ALZ-7). A child is particularly preferable, and a ligand represented by the formula (ALZ-1) or (ALZ-7) is most preferable.

In the formula, Ac represents an acidic group or a salt thereof. Ac is preferably the above-mentioned acidic group Ac. i1 represents a number of 1 or more. j1 represents a number of 0 or more. When i1 is 2 or more, a plurality of Ac may be the same as or different from each other.
R ^Z2 and ^{R Z4} has the same meaning as ^{R Z2} and ^{R Z4} in formula (DLZ-1) ~ (DLZ -3).

Here, the upper limit of the sum total of i1 and j1 in each formula is indicated in {} of each formula. When j1 is 2 or more, a plurality of R ^Z2 may be the same as or different from each other, and may be bonded to each other to form a ring.
In formulas (ALZ-1) to (ALZ-6), i1 is preferably 1 or 2, and in formulas (ALZ-7) and (ALZ-8), i1 is preferably an integer of 1 to 3.

The above formula (ALZ-1) the ~ (ALZ-8), are shown a substituent R ^Z2 and Ac to extend the bond in a predetermined aromatic ring are not limited to those substituted on the aromatic ring. That is, for example, in Formula (ALZ-1), R ^Z2 and Ac are substituted on one pyridine ring, but these may be substituted on the other pyridine ring.

* Ligand Y ^Z
In formula (Z), Y ^Z represents a monodentate or bidentate ligand. zy represents the number of ligands ^YZ . zy represents an integer of 0 to 3, and zy is preferably an integer of 1 to 3. When ^YZ is a monodentate ligand, zy is preferably 2 or 3, and when ^YZ is a bidentate ligand, zy is preferably 1. When zy is 2 or more, plural Y ^Z may be the same or different from each other, a plurality of Y ^Z may be linked to each other.

The ligand ^YZ 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, or 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 with a group selected from the group consisting of acyloxy group, acylaminooxy group, dithiocarbamate group, thiocyanate group, isothiocyanate group, cyanate group, isocyanate group, cyano group or arylthio group, or A ligand comprising a halogen atom, 1,3-diketone or thiourea, particularly preferably coordinated with a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group, an isothiocyanate group, a cyanate group and an isocyanate group. A ligand or a ligand comprising a halogen atom or a 1,3-diketone, most preferably a ligand coordinated by a group selected from the group consisting of a dithiocarbamate group, a thiocyanate group and an isothiocyanate group Or a ligand comprising 1,3-diketone A. In addition, when the ligand ^YZ contains an alkyl part, an alkenyl part, an alkynyl part, an alkylene part, etc., these may be linear or branched, and may be substituted or unsubstituted. Further, when an aryl moiety, a heterocyclic moiety, a cycloalkyl moiety and the like are included, they may be substituted or unsubstituted, and may be monocyclic or condensed.

When Y ^Z is a bidentate ligand, Y ^Z acyloxy group, an acylthio group, thio acyl group, Chioashiruchio group, acylamino group, thiocarbamate group, dithiocarbamate group, thiocarbonate group, dithiocarbonate group, A ligand coordinated by a group selected from the group consisting of trithiocarbonate group, acyl group, alkylthio group, arylthio group, alkoxy group and aryloxy group, or 1,3-diketone, carbonamide, thiocarbonamide, Or the ligand which consists of thiourea is preferable. When ^YZ is a monodentate ligand, ^YZ is 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. It is preferably a ligand or a ligand comprising a halogen atom, carbonyl, dialkyl ketone, or thiourea.

* Counter ion CI
CI in formula (Z) 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 metal complex dye represented by the formula (Z) may be dissociated and have a negative charge because the substituent has a dissociable group. In this case, the charge of the whole metal complex dye represented by the formula (Z) becomes electrically neutral due to 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.

* Bonding group The metal complex dye represented by the formula (Z) preferably has at least one or more interlocking groups that bind or adsorb to the surface of the semiconductor fine particles. It is more preferable to have 1 to 6 bonding groups in the metal complex dye, and it is particularly preferable to have 1 to 4 bonding groups. Examples of the linking group include the acid group Ac described above.

Specific examples of the metal complex dye represented by the formula (Z) preferably used in the present invention are shown below, but the present invention is not limited thereto.
In addition, when the dye in the following specific example includes a ligand having a proton dissociable group, the ligand may be dissociated as necessary to release a proton (H ⁺ ). These are also included.
Here, Bu is a butyl group (—C ₄ H ₉ ).

The metal complex dye represented by the formula (Z) can be easily synthesized by a method cited in Japanese Patent Application Laid-Open No. 2001-291534, the method described in the document, or a method according to these methods.
In the metal complex dye represented by the formula (Z), the maximum absorption wavelength in the solution is preferably in the range of 300 to 1000 nm, more preferably in the range of 350 to 950 nm, and particularly preferably in the range of 370 to 900 nm. is there.
In the photoelectric conversion element and the dye-sensitized solar cell of the present invention, at least the metal complex dye represented by the formula (I) and the metal complex dye represented by the formula (Z) which is an optional component are used in combination. Thus, high conversion efficiency can be ensured using light having a wide range of wavelengths.

  The compounding ratio of the metal complex dye represented by the formula (I) and the metal complex dye represented by the formula (Z) is R / S = 95, where R is the former and S is the latter. / 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.

− Conductive support −
The conductive support is preferably a support made of glass or plastic having a conductive film layer on the surface, such as a metal, which is conductive in itself. Examples of the plastic support include a transparent polymer film described in paragraph No. 0153 of JP-A No. 2001-291534. As the support, in addition to glass and plastic, ceramic (Japanese Patent Laid-Open No. 2005-135902) or conductive resin (Japanese Patent Laid-Open No. 2001-160425) may be used. On the conductive support, the surface may have 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. And may have a light guide function described in JP-A-2002-260746.

  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.

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, and particularly preferably 80% or more. As the transparent conductive support, a glass or plastic coated with a conductive metal oxide is preferable. As the metal oxide, tin oxide is preferable, and indium-tin oxide and fluorine-doped oxide are particularly preferable. The coating amount of the conductive metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of glass or plastic support. When a transparent conductive support is used, light is preferably incident from the support side.

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

  The crystal structure of titania includes anatase type, brookite type, or rutile type, and anatase type and brookite type are preferable. Titania nanotubes, nanowires, and nanorods may be mixed with titania fine particles or used as a semiconductor electrode.

  The particle size of the semiconductor fine particles is 0.001 to 1 μm as the primary particle and 0.01 to 100 μm as the average particle size of the dispersion in the average particle size using the diameter when the projected area is converted into a circle. Is preferred. Examples of the method for coating the semiconductor fine particles on the conductive support include a wet method, a dry method, and other methods.

  In order to prevent reverse current due to direct contact between the electrolyte and the electrode, it is preferable to form a short-circuit prevention layer between the transparent conductive film and the semiconductor layer (photoreceptor layer). In order to prevent contact between the photoelectrode and the counter electrode, it is preferable to use a spacer or a separator. 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. In general, the greater the thickness of the layer containing the semiconductor fine particles (photoreceptor layer), the greater the amount of dye that can be carried per unit area and the higher the light absorption efficiency, but the longer the diffusion distance of the generated electrons, the greater the charge recombination. The loss due to will also increase. Although the preferable thickness of the photoreceptor layer which is a semiconductor layer changes with uses of an element, it is 0.1-100 micrometers typically. When using as a dye-sensitized solar cell, 1-50 micrometers is preferable and 3-30 micrometers is more preferable. The semiconductor fine particles may be fired 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 60 to 400 ° C.

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. The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, particularly preferably 0.1 to 10 mmol, per 1 m ² of the support. In this case, the amount of the metal complex dye of the present invention is preferably 5 mol% or more. Further, the adsorption amount of the dye to the semiconductor fine particles is preferably 0.001 to 1 mmol, more preferably 0.1 to 0.5 mmol, with respect to 1 g of the semiconductor fine particles. By using such a dye amount, the sensitizing effect in the semiconductor fine particles can be sufficiently obtained.
When the dye is a salt, the counter ion of the specific metal complex dye is not particularly limited, and examples thereof include alkali metal ions and quaternary ammonium ions.

  After adsorbing the dye, the surface of the semiconductor fine particles may be treated with amines. Preferable amines include pyridines (for example, 4-tert-butylpyridine, polyvinylpyridine) 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.

In the photoelectric conversion element (for example, photoelectric conversion element 10) and the dye-sensitized solar cell (for example, dye-sensitized solar cell 20) of the present invention, at least the metal complex dye of the present invention is used.
− Charge transfer layer −
The charge transfer layer used in the photoelectric conversion element of the present invention is a layer having a function of replenishing electrons to the oxidant of the dye, and is provided between the light receiving electrode (photoelectrode) and the counter electrode (counter electrode). The charge transfer layer includes an electrolyte. Examples of the electrolyte include a liquid electrolyte obtained by dissolving a redox couple in an organic solvent, a so-called gel electrolyte obtained by impregnating a polymer matrix obtained by dissolving a redox couple in an organic solvent, a molten salt containing a redox couple, and the like. . In order to increase the photoelectric conversion efficiency, a liquid electrolyte is preferable. As the solvent for the liquid electrolyte, a nitrile compound, an ether compound, an ester compound or the like is used, and a nitrile compound is preferable, and acetonitrile and methoxypropionitrile are particularly preferable.

  As an oxidation-reduction pair, for example, iodine and iodide (iodide salt, ionic liquid is preferable, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, methylpropylimidazolium iodide are preferable) Combinations, combinations of alkyl viologens (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and reduced forms thereof, combinations of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and oxidized forms thereof, divalent And trivalent iron complexes (for example, red blood salt and yellow blood salt), divalent and trivalent cobalt complexes, and the like. Of these, a combination of iodine and iodide, and a combination of divalent and trivalent cobalt complexes are preferred.

  In particular, the cobalt complex is preferably a complex represented by the following formula (CC).

    Co (LL) ma (X) mb · CI Formula (CC)

  In the formula (CC), LL represents a bidentate or tridentate ligand. X represents a monodentate ligand. ma represents an integer of 0 to 3. mb represents the integer of 0-6. CI represents a counter ion when a counter ion is required to neutralize the charge.

  Examples of the counter ion of CI include CI in the formula (Z).

  LL is preferably a ligand represented by the following formula (LC).

In the formula (LC), X ^LC1 and X ^LC3 each independently represent a carbon atom or a nitrogen atom. Here, when ^XLC1 is a carbon atom, the bond of ^NLC adjacent to ^XLC1 represents a double bond ( ^XLC1 = N), and when ^XLC3 is a carbon atom, the bond of N atom adjacent to ^XLC3 represents a double bond ^{(X LC3} = ^N), when ^{X LC1} is a nitrogen ^atom, bonded N atom adjacent to ^{X LC1} represents a single bond ^(X LC1 ^-N), if ^{X LC3} is a nitrogen atom, binding of N atoms adjacent to X ^LC3 represents a single bond ^(X LC3 -N).
Z ^LC1 , Z ^LC2 and Z ^LC3 each independently represent a nonmetallic atom group necessary for forming a 5-membered ring or a 6-membered ring. Z ^LC1 , Z ^LC2 and Z ^LC3 may have a substituent and may be closed with an adjacent ring via the substituent. Examples of the substituent include the substituent T described later. q represents 0 or 1; In addition, when q is 0, the carbon atom at the position where X ^LC3 is bonded to the 5-membered ring or 6-membered ring formed by Z ^LC2 is a hydrogen atom or a substituent other than the heterocyclic group formed by Z ^LC3 Join.

In the formula (CC), X includes Z ¹ in the formula (I), and a halogen ion is preferable.

  The ligand represented by the formula (LC) is more preferably a ligand represented by the following formulas (LC-1) to (LC-4).

R ^{LC1 to} R ^LC11 each independently represent a substituent. q1, q2, q6 and q7 each independently represents an integer of 0 to 4. q3, q5, q10 and q11 each independently represents an integer of 0 to 3. q4 represents an integer of 0 to 2.

In the formulas (LC-1) to (LC-4), ^examples of the substituent represented by R ^{LC1 to} R ^LC11 include an aliphatic group, an aromatic group, and a heterocyclic group. Specific examples of the substituent include alkyl groups, alkoxy groups, alkylthio groups, aryl groups, aryloxy groups, arylthio groups, and heterocyclic rings. Preferred examples include alkyl groups (eg methyl, ethyl, n-butyl, n-hexyl, isobutyl, sec-butyl, t-butyl, n-dodecyl, cyclohexyl, benzyl etc.), aryl groups (eg phenyl, tolyl, naphthyl). Etc.), alkoxy groups (eg methoxy, ethoxy, isopropoxy, butoxy etc.), alkylthio groups (eg methylthio, n-butylthio, n-hexylthio, 2-ethylhexylthio etc.), aryloxy groups (eg phenoxy, naphthoxy etc.) Etc.), arylthio groups (eg, phenylthio, naphthylthio, etc.), and heterocyclic groups (eg, 2-thienyl, 2-furyl, etc.).

  Specific examples of the cobalt complex having a ligand represented by the formula (LC) include the following complexes.

  When a combination of iodine and iodide is used as the electrolyte, it is preferable to further use an iodine salt of a 5-membered or 6-membered nitrogen-containing aromatic cation.

  As the organic solvent for dissolving the redox couple, etc., an aprotic polar solvent (for example, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3-methyloxazolidinone, etc.) is preferable. . Examples of the polymer (polymer matrix) used in the gel electrolyte matrix include polyacrylonitrile and polyvinylidene fluoride. Examples of the molten salt include those imparted with fluidity at room temperature by mixing polyethylene oxide with lithium iodide and at least one other lithium salt (such as lithium acetate and lithium perchlorate). It is done. In this case, the amount of the polymer added is 1 to 50% by mass. Moreover, (gamma) -butyrolactone may be contained in electrolyte solution, and thereby the diffusion efficiency of iodide ion becomes high and photoelectric conversion efficiency improves.

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

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

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

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

  The electrolyte may be quasi-solidified by adding a gelling agent to an electrolyte solution composed of an electrolyte and a solvent to cause gelation (hereinafter, the quasi-solid electrolyte is also referred to as “pseudo-solid electrolyte”). Examples of the gelling agent include organic compounds having a molecular weight of 1000 or less, Si-containing compounds having a molecular weight in the range of 500 to 5000, organic salts composed of specific acidic compounds and basic compounds, sorbitol derivatives, and polyvinylpyridine.

Alternatively, a method of confining the matrix polymer, the crosslinkable polymer compound or monomer, the crosslinking agent, the electrolyte, and the solvent in the polymer may be used.
As a matrix polymer, a polymer having a nitrogen-containing heterocyclic ring in the main chain or side chain repeating unit, a crosslinked product obtained by reacting these with an electrophilic compound, a polymer having a triazine structure, or having a ureido structure Inclusion of polymers, liquid crystal compounds, ether-bonded polymers, polyvinylidene fluoride, methacrylate / acrylate, thermosetting resins, cross-linked polysiloxane, polyvinyl alcohol (PVA), polyalkylene glycol and dextrin Examples thereof include compounds, systems to which oxygen-containing or sulfur-containing polymers are added, natural polymers, and the like. An alkali swelling polymer, a polymer having a compound capable of forming a charge transfer complex of a cation moiety and iodine in one polymer, and the like may be added to these.

  As the polymer matrix, a system containing a crosslinked polymer obtained by reacting a bifunctional or higher functional isocyanate with a functional group such as a hydroxy group, an amino group, or a carboxy group may be used. In addition, a crosslinking method in which a crosslinked polymer composed of a hydrosilyl group and a double bond compound, polysulfonic acid, polycarboxylic acid, or the like is reacted with a divalent or higher valent metal ion compound may be used.

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

  Instead of the above liquid electrolyte and quasi-solid electrolyte, a solid charge transport layer such as a p-type semiconductor or a hole transport material, for example, CuI, CuNCS or the like can be used. Also, Nature, vol. 486, p. The electrolyte described in 487 (2012) or the like may be used. An organic hole transport material may be used as the solid charge transport layer. The organic hole transport material is preferably a conductive polymer such as polythiophene, polyaniline, polypyrrole and polysilane, and a spiro compound in which two rings share a central element having a tetrahedral structure such as C and Si, a triarylamine, etc. Aromatic amine derivatives, triphenylene derivatives, nitrogen-containing heterocyclic derivatives, liquid crystal cyano derivatives are exemplified.

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

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

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

In the formula (CA), R ^C1 represents a substituent having an acidic group. R ^C2 represents a substituent. lc represents an integer of 0 or more.
An acidic group is synonymous with acidic group Ac shown previously, and its preferable range is also the same.
Among these, R ^C1 is preferably an alkyl group substituted with a carboxy group or a sulfo group or a salt thereof, —CH (CH ₃ ) CH ₂ CH ₂ CO ₂ H, —CH (CH ₃ ) CH ₂ CH ₂ CONHCH. More preferred is ₂ CH ₂ SO ₃ H.

Examples of R ^C2 include the substituent T described later, and among them, an alkyl group, a hydroxy group, an acyloxy group, an alkylaminocarbonyloxy group, and an arylaminocarbonyloxy group are preferable, and an alkyl group, a hydroxy group, and an acyloxy group are more preferable. .
As for lc, 2-4 are preferable.

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

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

<Substituent T>
In this specification, about the display of a compound (a complex and a pigment | dye are included), it uses for the meaning containing the salt and its ion besides the said compound itself. In addition, in the present specification, a substituent that does not specify substitution / non-substitution (the same applies to a linking group and a ligand) means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substituted or unsubstituted. Preferred substituents include the following substituent T.
Further, in the present specification, when only described as a substituent, it refers to this substituent T, and each group, for example, an alkyl group, is only described. The preferred range and specific examples of the corresponding group of the substituent T are applied.

Examples of the substituent T include the following.
An alkyl group (preferably having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, trifluoromethyl, etc.), Alkenyl groups (preferably having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), alkynyl groups (preferably having 2 to 20 carbon atoms, such as ethynyl, butynyl, phenylethynyl, etc.), cycloalkyl groups (preferably Have 3 to 20 carbon atoms, for example, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), cycloalkenyl groups (preferably 5-20 carbon atoms, for example, cyclopentenyl, cyclohexenyl, etc.), aryl groups (preferably Has 6 to 26 carbon atoms, for example, phenyl, 1-na Til, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl and the like), a heterocyclic group (preferably having 2 to 20 carbon atoms and having at least one oxygen atom, sulfur atom or nitrogen atom) A heterocyclic group of a ring is more preferable, for example, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2-thiazolyl, 2-oxazolyl and the like, an alkoxy group (preferably having 1 to 20 carbon atoms, , Methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), alkenyloxy groups (preferably having 2 to 20 carbon atoms, for example, vinyloxy, allyloxy, etc.), alkynyloxy groups (preferably having 2 to 20 carbon atoms, for example, 2 -Propynyloxy, 4-butynyloxy, etc.), cycloalkyloxy groups (preferably carbon 3 to 20, for example, cyclopropyloxy, cyclopentyloxy, cyclohexyloxy, 4-methylcyclohexyloxy, etc.), an aryloxy group (preferably having 6 to 26 carbon atoms, for example, phenoxy, 1-naphthyloxy, 3-methyl Phenoxy, 4-methoxyphenoxy, etc.), heterocyclic oxy group (for example, imidazolyloxy, benzoimidazolyloxy, thiazolyloxy, benzothiazolyloxy, triazinyloxy, purinyloxy),

Alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, for example, ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.), cycloalkoxycarbonyl group (preferably having 4 to 20 carbon atoms, for example, cyclopropyloxycarbonyl, cyclopentyloxycarbonyl, etc. , Cyclohexyloxycarbonyl, etc.), aryloxycarbonyl groups (preferably having 6 to 20 carbon atoms, such as phenyloxycarbonyl, naphthyloxycarbonyl, etc.), amino groups (preferably having 0 to 20 carbon atoms, alkylamino groups, alkenyls) Including amino group, alkynylamino group, cycloalkylamino group, cycloalkenylamino group, arylamino group, heterocyclic amino group, for example, amino, N, N-dimethylamino, N, N-diethylamino, N-ethyl Amino, N-allylamino, N- (2-propynyl) amino, N-cyclohexylamino, N-cyclohexenylamino, anilino, pyridylamino, imidazolylamino, benzoimidazolylamino, thiazolylamino, benzothiazolylamino, triazinylamino, etc.) A sulfamoyl group (preferably an alkyl, cycloalkyl or aryl sulfamoyl group having 0 to 20 carbon atoms, such as N, N-dimethylsulfamoyl, N-cyclohexylsulfamoyl, N-phenylsulfamoyl, etc. ), An acyl group (preferably having 1 to 20 carbon atoms, such as acetyl, cyclohexylcarbonyl, benzoyl, etc.), an acyloxy group (preferably having 1 to 20 carbon atoms, such as acetyloxy, cyclohexylcarbonyloxy). , Benzoyloxy, etc.), carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, alkyl, cycloalkyl or aryl, such as N, N-dimethylcarbamoyl, N-cyclohexylcarbamoyl, N-phenylcarbamoyl, etc.) ,

An acylamino group (preferably an acylamino group having 1 to 20 carbon atoms, such as acetylamino, cyclohexylcarbonylamino, benzoylamino, etc.), a sulfonamide group (preferably a sulfoamide having 0 to 20 carbon atoms, alkyl, cycloalkyl or aryl) Groups such as methanesulfonamide, benzenesulfonamide, N-methylmethanesulfonamide, N-cyclohexylsulfonamide, N-ethylbenzenesulfonamide, etc., alkylthio groups (preferably having 1 to 20 carbon atoms, for example methylthio , Ethylthio, isopropylthio, benzylthio, etc.), cycloalkylthio group (preferably having 3 to 20 carbon atoms, such as cyclopropylthio, cyclopentylthio, cyclohexylthio, 4-methylcyclohexylthio Etc.), an arylthio group (preferably having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), alkyl, cycloalkyl or arylsulfonyl group (preferably having a carbon number) 1-20, for example, methylsulfonyl, ethylsulfonyl, cyclohexylsulfonyl, benzenesulfonyl, etc.),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy and aryloxy, such as triethylsilyl, triphenylsilyl, diethylbenzylsilyl, dimethylphenylsilyl, etc.), silyloxy group ( Preferably, it is a silyloxy group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy and aryloxy, such as triethylsilyloxy, triphenylsilyloxy, diethylbenzylsilyloxy, dimethylphenylsilyloxy, etc.), a hydroxy group , Cyano group, nitro group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), carboxy group, sulfo group, phosphonyl group, phosphoryl group, boric acid group, more preferably alkyl group, A kenyl group, cycloalkyl group, aryl group, heterocyclic group, alkoxy group, cycloalkoxy group, aryloxy group, alkoxycarbonyl group, cycloalkoxycarbonyl group, the above amino group, acylamino group, cyano group or halogen atom, 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 is preferable.

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

<Counter electrode (counter electrode)>
The counter electrode is preferably a positive electrode of a dye-sensitized solar cell (photoelectrochemical cell). The counter electrode is usually synonymous with the conductive support described above, but the support is not necessarily required in a configuration in which the strength is sufficiently maintained. As the structure of the counter electrode, a structure having a high current collecting effect is preferable. In order for light to reach the photoreceptor layer, at least one of the conductive support and the counter electrode described above must be substantially transparent. In the dye-sensitized solar cell of the present invention, the conductive support is preferably transparent, and sunlight is preferably incident from the support side. In this case, it is more preferable that the counter electrode has a property of reflecting light. As a counter electrode of the dye-sensitized solar cell, glass or plastic on which metal or conductive oxide is vapor-deposited is preferable, and glass on which platinum is vapor-deposited is particularly preferable. In the dye-sensitized solar cell, it is preferable to seal the side surface of the battery with a polymer, an adhesive or the like in order to prevent the constituents from evaporating.

  The present invention is disclosed in Japanese Patent No. 4260494, Japanese Patent Application Laid-Open No. 2004-146425, Japanese Patent Application Laid-Open No. 2000-340269, Japanese Patent Application Laid-Open No. 2002-289274, Japanese Patent Application Laid-Open No. 2004-152613, and Japanese Patent Application Laid-Open No. 9-27352. It can apply to the described photoelectric conversion element and a dye-sensitized solar cell. JP-A-2004-152613, JP-A-2000-90989, JP-A-2003-217688, JP-A-2002-367686, JP-A-2003-323818, JP-A-2001-43907, JP 2000-340269, JP 2005-85500, JP 2004-273272, JP 2000-323190, JP 2000-228234, JP 2001-266963, JP 2001-185244, JP-T-2001-525108, JP-A-2001-203377, JP-A-2000-1000048, JP-A-2001-210390, JP-A-2002-280588, JP-A-2001-2001. 273937, JP-A 2000-2859 7 No. photoelectric conversion device described in JP 2001-320068 Patent Publication can be applied to a dye-sensitized solar cell.

<< Dye Solution, Dye-Adsorbing Electrode and Dye-Sensitized Solar Cell Manufacturing Method Using It >>
In this invention, it is preferable to manufacture a pigment | dye adsorption electrode using the pigment | dye solution containing the metal complex pigment | dye of this invention.
In such a dye solution, the metal complex dye of the present invention is dissolved in a solvent and may contain a co-adsorbent and other components as necessary.
Examples of the solvent to be used include, but are not limited to, the solvents described in JP-A No. 2001-291534. In the present invention, an organic solvent is preferable, and alcohols, amides, nitriles, hydrocarbons, and a mixed solvent of two or more of these are preferable. As the mixed solvent, a mixed solvent of an alcohol and a solvent selected from amides, nitriles or hydrocarbons is preferable. Further preferred are alcohols and amides, mixed solvents of alcohols and hydrocarbons, and particularly preferred are mixed solvents of alcohols and amides. Specifically, methanol, ethanol, propanol, butanol, dimethylformamide, and dimethylacetamide are preferable.

The dye solution preferably contains a co-adsorbent. As the co-adsorbent, the above-mentioned co-adsorbent is preferable, and among them, the compound represented by the formula (CA) is preferable.
Here, the density | concentration of a metal complex pigment | dye or a coadsorbent is adjusted so that the pigment | dye solution used for this invention can use this solution as it is, when manufacturing a photoelectric conversion element and a dye-sensitized solar cell. A dye solution is preferred. In this invention, it is preferable to contain the metal complex pigment | dye of this invention 0.001-0.1 mass%.

In the dye solution, it is particularly preferable to adjust the water content. Therefore, in the present invention, the water content (content ratio) is preferably adjusted to 0 to 0.1% by mass.
Similarly, adjustment of the water content of the electrolyte in the photoelectric conversion element and the dye-sensitized solar cell is also preferable in order to effectively achieve the effects of the present invention. For this reason, the water content (content) of the electrolyte is set to 0. It is preferable to adjust to -0.1 mass%. The electrolyte is particularly preferably adjusted with a dye solution.

In the present invention, a dye adsorption electrode which is a semiconductor electrode for a dye-sensitized solar cell in which a metal complex dye is supported on the surface of a semiconductor fine particle provided in a semiconductor electrode using the dye solution is preferable.
That is, a dye-adsorbing electrode for a dye-sensitized solar cell is obtained by applying a composition obtained from the dye solution onto a conductive support provided with semiconductor fine particles, and curing the composition after application. What was made into the photoreceptor layer is preferable.
In the present invention, it is preferable to produce a dye-sensitized solar cell by using the dye-adsorbing electrode for the dye-sensitized solar cell, preparing an electrolyte and a counter electrode, and assembling them using these.

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

<Synthesis of metal complex dye>
Hereinafter, the synthesis method of the metal complex dye of the present invention will be described in detail by way of examples. However, the starting material, the intermediate of the metal complex dye, and the synthesis route are not limited thereto.

(Synthesis of metal complex dye D-1-1a)
A metal complex dye D-1-1a was synthesized according to the method of the following scheme.

(I) Synthesis of Compound d-1-2 25 g of Compound d-1-1 (2-acetyl-4-methylpyridine) was dissolved in 200 ml of THF (tetrahydrofuran) and sodium was stirred at 0 ° C. in a nitrogen atmosphere. 18.9 g of ethoxide was added and stirred for 15 minutes. Thereafter, 28.9 g of ethyl trifluoroacetate was added dropwise to the stirred solution, and the mixture was stirred at an external temperature of 70 ° C. for 20 hours. After returning to room temperature, an aqueous ammonium chloride solution was added dropwise to separate the solution. The organic phase was concentrated to obtain 72.6 g of a crude product d-1-2.

(Ii) Synthesis of Compound d-1-3 After dissolving 72.6 g of Compound d-1-2 in 220 ml of ethanol, 5.6 ml of hydrazine monohydrate was added while stirring at room temperature in a nitrogen atmosphere. The mixture was heated at an external temperature of 90 ° C. for 12 hours. Thereafter, 5 ml of concentrated hydrochloric acid was added thereto and stirred for 1 hour. After the stirred solution was concentrated, 150 ml of sodium bicarbonate water and 150 ml of ethyl acetate were added to extract the reaction product, and the organic phase was concentrated. After recrystallization from acetonitrile, 31.5 g of compound d-1-3 was obtained.

(Iii) Synthesis of Compound d-1-5 After dropwise addition of 23.1 ml of 1.6M n-butyllithium hexane solution while stirring 4.1 g of diisopropylamine and 30 ml of tetrahydrofuran at −40 ° C. in a nitrogen atmosphere, Stir for 2 hours. Next, 4.0 g of the compound d-1-3 was added thereto and stirred at 0 ° C. for 80 minutes, and then a solution obtained by dissolving 3.22 g of the compound d-1-4 in 15 ml of tetrahydrofuran was added dropwise. Furthermore, the solution after dropping was stirred at 0 ° C. for 80 minutes and then at room temperature for 5 hours. Thereafter, an ammonium chloride solution was added to the reaction solution, and the reaction product was extracted with ethyl acetate. The organic phase was concentrated and purified by silica gel column chromatography to obtain 5.5 g of compound d-1-5.

(Iv) Synthesis of compound d-1-6 5.0 g of compound d-1-5 and 5.7 g of PPTS (pyridinium paratoluenesulfonic acid) are added to 50 ml of toluene, and the mixture is heated to reflux for 5 hours in a nitrogen atmosphere. It was. After the refluxed solution was concentrated, saturated aqueous sodium hydrogen carbonate and methylene chloride were added for liquid separation, and the organic phase was concentrated. The obtained crystals were recrystallized from methanol and methylene chloride to obtain 4.2 g of compound d-1-6.
The structure of the obtained compound d-1-6 was confirmed by MS (mass spectrum) measurement.
MS-ESI m / z = 464.1 (M + H) ⁺

(V) Synthesis of Metal Complex Dye D-1-1a 1.15 g of compound d-1-7 and 1.59 g of compound d-1-6 were added to 150 ml of NMP (N-methylpyrrolidone), and under a nitrogen atmosphere. , And stirred at 70 ° C. for 3 hours. Subsequently, 1.52 g of compound d-1-8 was added thereto, and the mixture was heated and stirred at 160 ° C. for 8 hours. Thereafter, 10.0 g of ammonium thiocyanate was added and stirred at 160 ° C. for 8 hours. After the stirred solution was concentrated, water was added and filtered. The residue was purified by silica gel column chromatography, added to a mixed solvent of 30 ml of acetone and 40 ml of 1N aqueous sodium hydroxide solution, and stirred at an external temperature of 65 ° C. for 24 hours. The solution after the reaction was returned to room temperature, and the pH was adjusted to 1.5 by adding hydrochloric acid. The resulting precipitate was filtered to obtain 3.2 g of a crude product D-1-1a.
The roughly purified product D-1-1a obtained above was dissolved in a methanol solution together with TBAOH (tetrabutylammonium hydroxide) and purified using a Sephadex LH-20 column. The fraction of the main layer was collected, concentrated, and adjusted to pH 3 by adding a 0.1 M trifluoromethanesulfonic acid solution. The resulting precipitate was filtered to obtain 2.2 g of a metal complex dye D-1-1a.
The structure of the obtained metal complex dye D-1-1a was confirmed by MS measurement.
MS-ESI m / z = 988.1 (M + H) ⁺
When the obtained metal complex dye D-1-1a was adjusted with a DMF (dimethylformamide) solvent so that the dye concentration was 17 μmol / l and subjected to spectral absorption measurement, the maximum absorption wavelength was 530 nm.

(Synthesis of Metal Complex Dye D-1-5a)
Compound d-2-2 was synthesized according to the method of the following scheme. The metal complex dye D-1-5a was synthesized in the same manner as the metal complex dye D-1-1a except that the compound d-1-4 of the metal complex dye D-1-1a was changed to the compound d-2-2. Was synthesized.

(Synthesis of Dye D-1-6a)
Compound d-3-3 was synthesized according to the method of the following scheme. The metal complex dye D-1-6a was synthesized in the same manner as the metal complex dye D-1-1a except that the compound d-1-4 of the metal complex dye D-1-1a was changed to the compound d-3-3. Was synthesized.

(Synthesis of Metal Complex Dye D-1-8a)
Compound d-4-2 was synthesized according to the method of the following scheme. In the synthesis of the metal complex dye D-1-1a, except that the compound d-1-4 was changed to the compound d-4-2, the same as the synthesis of the metal complex dye D-1-1a, the metal complex dye D- 1-8a was synthesized.

(Synthesis of Metal Complex Dye D-1-9a)
Compound d-5-8 was synthesized according to the method of the following scheme. In the synthesis of the metal complex dye D-1-1a, the metal complex dye D- is the same as the synthesis of the metal complex dye D-1-1a except that the compound d-1-6 is changed to the compound d-5-8. 1-9a was synthesized.

(Synthesis of Metal Complex Dye D-1-16a)
In the synthesis of the metal complex dye D-1-1a, except that the compound d-1-1 was changed to the compound d-14-1, the metal complex dye D- 1-16a was synthesized.

(Synthesis of Metal Complex Dye D-1-26a)
Compound d-13-3 was synthesized according to the method of the following scheme. A metal complex dye D-1-26a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-3 was changed to the compound d-13-3.

(Synthesis of Metal Complex Dye D-1-18a)
A metal complex dye D-1-18a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-1 was changed to the compound d-12-1.

(Synthesis of Metal Complex Dye D-3-1a)
In the synthesis of the metal complex dye D-1-1a, the metal complex dye D is the same as the synthesis of the metal complex dye D-1-1a except that the compound d-1-7 is changed to the compound d-15-1. -3-1a was synthesized. A synthesis scheme of metal complex dye D-3-1a using compound d-15-1 is shown below.

(Synthesis of Metal Complex Dye D-1-35a)
Compound d-16-2 was synthesized according to the method of the following scheme. A metal complex dye D-1-35a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-3 was changed to the compound d-16-2.

(Synthesis of Metal Complex Dye D-1-36a)
Compound d-17-3 was synthesized according to the method of the following scheme. A metal complex dye D-1-36a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-3 was changed to the compound d-17-3.

(Synthesis of Metal Complex Dye D-1-37a)
Compound d-18-1 was synthesized according to the method of the following scheme. A metal complex dye D-1-37a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-3 was changed to the compound d-18-1.

(Synthesis of metal complex dye D-3-5a)
A metal complex dye D-3-5a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that ammonium thiocyanate was changed to the compound d-19-1.

(Synthesis of Metal Complex Dye D-1-38a)
In the synthesis of the metal complex dye D-1-1a, except that the compound d-1-4 was changed to the compound d-20-1, the same as the synthesis of the metal complex dye D-1-1a, the metal complex dye D- 1-38a was synthesized.
Compound d-20-1 was prepared according to the method of Monatsberichte der Deutschen Akademie der Wissenschaffen zu Berlin, 1959, vol. 1, synthesized by the method described in p180.

(Synthesis of metal complex dye D-1-32a)
A metal complex dye D-1-32a was synthesized in the same manner as the metal complex dye D-1-1a except that ammonium thiocyanate was changed to potassium iodide.

(Synthesis of metal complex dye D-2-1a)
A metal complex dye D-2-1a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-8 was changed to the compound d-21-1.
Compound d-21-1 can be obtained from Inorganic Chemistry, Vol. 36, no. 25, 1997, 5939.

(Synthesis of metal complex dye D-2-8a)
A metal complex dye D-2-8a was synthesized in the same manner as the synthesis of the metal complex dye D-1-1a except that the compound d-1-8 was changed to the compound d-22-1.
Compound d-22-1 was prepared according to Eur. J. et al. Inorg. Chem. , 2002, 3101-3110.

(Synthesis of Metal Complex Dye D-1-7a)
Advanced Synthesis and Catalysis, 2012, vol. 354, # 8, p. With reference to the synthesis method described in 1542 to 1550, compound d-4-1 used for the synthesis of metal complex dye D-1-8a was reduced to synthesize compound d-23-1. In the same manner as in metal complex dye D-1-8a, compound d-4-1 was changed to compound d-23-1 to synthesize metal complex dye D-1-7a.

(Synthesis of Metal Complex Dye D-1-28a)
A metal complex dye D-1-28a was synthesized in the same manner as the metal complex dye D-1-1a except that ammonium thiocyanate was changed to potassium selenocyanate.

(Synthesis of Metal Complex Dye D-1-29a)
A metal complex dye D-1-29a was synthesized in the same manner as the metal complex dye D-1-1a except that ammonium thiocyanate was changed to potassium cyanate.

(Synthesis of Metal Complex Dye D-1-33a)
A metal complex dye D-1-33a was synthesized in the same manner as the metal complex dye D-1-1a except that ammonium thiocyanate was changed to potassium cyanate.

(Synthesis of Metal Complex Dye D-1-3a)
Compound d-24-3 was synthesized according to the method of the following scheme. In the synthesis of the metal complex dye D-1-1a, except that the compound d-1-4 was changed to the compound d-24-3, the same as the synthesis of the metal complex dye D-1-1a, the metal complex dye D- 1-3a was synthesized.

The structure of each metal complex dye was confirmed by MS measurement.
The results of MS measurement for each metal complex dye are summarized in Table 6 below.

  The metal complex dye synthesized by the above method is shown below.

Example 1
Various pastes for forming the semiconductor layer or light scattering layer of the semiconductor electrode (photoreceptor layer) constituting the photoelectrode were prepared, and dye-sensitized solar cells were prepared using the paste.

[Preparation of paste]
First, a paste for forming a semiconductor layer or a light scattering layer of a semiconductor electrode constituting a photoelectrode was prepared with the composition shown in Table 7 below. In the following preparation, a slurry was prepared by putting TiO ₂ particles in a medium and stirring, and a thickener was added thereto and kneaded to obtain a paste.

TiO ₂ particles 1: anatase, average particle size; 25 nm
TiO ₂ particles 2: anatase, average particle size; 200 nm
Rod-like TiO ₂ particles S1: anatase, diameter: 100 nm, aspect ratio: 5
Rod-like TiO ₂ particles S2: anatase, diameter: 30 nm, aspect ratio: 6.3
Rod-like TiO ₂ particles S3: anatase, diameter: 50 nm, aspect ratio: 6.1
Rod-like TiO ₂ particles S4: anatase, diameter: 75 nm, aspect ratio: 5.8
Rod-like TiO ₂ particles S5: anatase, diameter: 130 nm, aspect ratio: 5.2
Rod-like TiO ₂ particles S6: anatase, diameter; 180 nm, aspect ratio: 5
Rod-like TiO ₂ particles S7: anatase, diameter; 240 nm, aspect ratio: 5
Rod-like TiO ₂ particles S8: anatase, diameter: 110 nm, aspect ratio: 4.1
Rod-like TiO ₂ particles S9: anatase, diameter: 105 nm, aspect ratio: 3.4
Plate-like mica particles P1: Diameter: 100 nm, aspect ratio: 6
CB: Cellulosic binder

  A photoelectrode having the same configuration as the photoelectrode 12 shown in FIG. 5 described in JP-A-2002-289274 is prepared by the following procedure, and further replaced with the photoelectrode shown in FIG. A 10 mm × 10 mm scale dye-sensitized solar cell 1 having the same configuration as that of the dye-sensitized solar cell 20 of FIG. 3 except that this photoelectrode was used was produced. The specific configuration is shown in FIG. 41 is a transparent electrode, 42 is a semiconductor electrode, 43 is a transparent conductive film, 44 is a substrate, 45 is a semiconductor layer, 46 is a light scattering layer, 40 is a photoelectrode, 20 is a dye-sensitized solar cell, CE is a counter electrode, and E is The electrolyte, S, is a spacer.

A transparent electrode 41 (conductive support) in which a fluorine-doped SnO ₂ conductive film (transparent conductive film 43, film thickness: 500 nm) was formed on a glass substrate (substrate 44) was prepared. Then, the SnO ₂ conductive film, a paste 2 described above by screen printing and then dried. Then, it baked on the conditions of 450 degreeC in the air. Furthermore, by repeating screen printing and baking using the paste 4, the semiconductor electrode A (light receiving surface area; 10 mm × 10 mm, layer) having the same configuration as the semiconductor electrode 42 shown in FIG. 2 is formed on the SnO ₂ conductive film. 15 μm, layer thickness of semiconductor layer; 10 μm, layer thickness of light scattering layer; 5 μm, content of rod-like TiO ₂ particles S1 contained in the light scattering layer; 30% by mass) (photoreceptor layer), Photoelectrode A containing no dye was prepared.

Next, the pigment | dye was made to adsorb | suck to the semiconductor electrode A as follows. First, using anhydrous ethanol dehydrated with magnesium ethoxide as a solvent, a metal complex dye described in Table 8 below was weighed so that its concentration was 2 × 10 ⁻⁴ mol / L to prepare a dye solution. . Next, the semiconductor electrode A was immersed in this solution, thereby completing the photoelectrode A in which the dye was adsorbed to the semiconductor electrode A by about 1.5 × 10 ⁻⁷ mol / cm ² .

Next, a platinum electrode (thickness of Pt thin film; 100 nm) having the same shape and size as the above-mentioned photoelectrode A as the counter electrode CE, and 5 v / v% in acetonitrile solution containing iodine and lithium iodide as the electrolyte E It was prepared by adding ultrapure water. Further, a DuPont spacer S (trade name: “Surlin”) having a shape corresponding to the size of the semiconductor electrode A is prepared, as shown in FIG. 3 described in JP-A-2002-289274. And a photoelectrode A, a counter electrode CE, and a spacer S, and a dye-sensitized solar cell (cell A) using the photoelectrode A by filling the above-described electrolyte (forming a charge transfer layer). ) Was completed.
The performance of this dye-sensitized solar cell was evaluated. The results are shown in Table 8 below.

(Water resistance test under various test conditions)
Each evaluation was performed by the method shown below.

[Test method]
The dye-sensitized solar cell was subjected to a aging test (water resistance test) in a dark place at 60 ° C. for 400 hours, and evaluated by the rate of decrease in photoelectric conversion efficiency.
The photoelectric conversion efficiency η (%) was determined for each dye-sensitized solar cell (cell A) before and after the time test. A solar simulator (WACOM, WXS-85H) was used to radiate 1000 W / m ² of artificial sunlight from a xenon lamp through an AM1.5 filter using an I-V tester (KEITHLEY, Series 2400 SourceMeter (registered trademark). )) Was used to measure current-voltage characteristics.
The reduction rate (%) of the photoelectric conversion efficiency after the water resistance test was determined by [(initial photoelectric conversion efficiency−photoelectric conversion efficiency after water resistance test) / initial photoelectric conversion efficiency] × 100.
Both the initial conversion efficiency and the rate of decrease in photoelectric conversion efficiency after the water resistance test are acceptable levels.
Table 8 shows the results of the initial conversion efficiency and the rate of decrease in photoelectric conversion efficiency after the water resistance test using the following symbols AA to F.

Initial conversion efficiency AA: 8.0% or more A: 7.4% or more, less than 8.0% B: 6.8% or more, less than 7.4% C: 6.2% or more, less than 6.8% D : 6.0% or more and less than 6.2% E: 5.8% or more and less than 6.0% F: Less than 5.8%

Rate of decrease in photoelectric conversion efficiency after water resistance test AA: less than 4% A: 4% or more, less than 6% B: 6% or more, less than 8% C: 8% or more, less than 10% D: 10% or more, 12 Less than% E: 12% or more, less than 20% F: 20% or more

  It can be seen that all of the photoelectric conversion elements using the metal complex dye of the present invention are excellent not only in the initial photoelectric conversion efficiency but also in the reduction rate (water resistance) of the photoelectric conversion efficiency after the water resistance test. . From the above results, it can be seen that the metal complex dye of the present invention has achieved the problem of achieving both high photoelectric conversion efficiency and water resistance.

  Further, in the production of the photoelectrode A, each photoelectrode was produced in the same manner as the production of the photoelectrode A except that the pastes 1 to 14 were used instead of the paste 2 used for forming the semiconductor layer. When the water resistance test was similarly performed on the dye-sensitized solar cell, it was confirmed that all the dye-sensitized solar cells using the metal complex dye of the present invention had good performance.

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

SnO ₂ : F (fluorine-doped tin oxide, hereinafter also referred to as “FTO”) was vapor-deposited on a transparent glass plate (transparent substrate 51) having a size of 20 mm × 20 mm × 1 mm by CVD to form a transparent conductive film 52. A transparent conductive glass substrate (TCO glass substrate, TCO: Transparent Conductive Oxide) was prepared.
Next, 5 ml of a solution in which Ti [OCH (CH ₃ ) ₂ ] ₄ and water are mixed at a volume ratio of 4: 1 and 40 ml of an ethyl alcohol solution adjusted to pH 1 with hydrochloride are mixed to obtain a TiO ₂ precursor. A solution of was prepared. And this solution was spin-coated at 1000 rpm on the TCO glass substrate, and sol-gel synthesis was performed. Next, the TCO glass substrate after sol-gel synthesis was heated under vacuum at 78 ° C. for 45 minutes, and then annealed at 450 ° C. for 30 minutes to form a barrier layer 53 made of a titanium oxide thin film.

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

The titanium oxide particle-containing composition thus prepared was applied on the barrier layer 53 formed above so as to form a predetermined pattern by screen printing, dried at 150 ° C., and then in an electric furnace. By heating to 450 ° C., a laminate in which the n-type semiconductor electrode 54 was laminated on the barrier layer 53 was obtained. Next, this laminate was immersed in a zinc nitrate (ZnNO ₃ ) solution overnight, and then heated at 450 ° C. for 45 minutes for surface treatment. Thereafter, the surface-treated laminate was immersed in an ethanol solution (concentration of sensitizing dye: 1 × 10 ⁻⁴ mol / L) using various metal complex dyes shown in Table 8, and 24 hours at 25 ° C. The dye was adsorbed inside the n-type semiconductor electrode 54 by allowing it to stand.

  Subsequently, CuI was added to acetonitrile to prepare a saturated solution, and 6 ml of the supernatant was taken out. Thereto was added 15 mg of 1-methyl-3-ethylimidazolium thiocyanate to prepare a p-type semiconductor solution. Then, on the hot plate heated to 80 ° C., the stacked body after the dye is added to the n-type semiconductor electrode 54 is placed, and the p-type semiconductor solution is put on the n-type semiconductor electrode 54 using a pipette. It was applied dropwise and allowed to penetrate. The p-type semiconductor layer 55 was formed by leaving it to stand for 1 minute and drying it.

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

  The dye-sensitized solar cell thus produced was evaluated for initial conversion efficiency and water resistance in the same manner as in Example 1. As a result, it was confirmed that the metal complex dyes of the present invention can provide good performance and improvement effect.

(Example 3)
The CdSe quantum dotization process was performed to the photoelectrode with the following method, and the dye-sensitized solar cell shown in FIG.1 and FIG.4 was produced using the electrolyte using a cobalt complex.

An ethanol solution of titanium (IV) bis (acetylacetonate) diisopropoxide was sprayed 16 times on the surface of FTO glass (manufactured by Nippon Sheet Glass Co., Ltd., surface resistance: 8Ω sq ⁻¹ ), and baked at 450 ° C. for 30 minutes or more. A substrate was obtained. On this substrate, a transparent layer of about 2.1 μm with 30 nm-TiO ₂ (manufactured by Showa Titanium Co., Ltd.) and a light scattering layer of about 6.2 μm with 60 nm-TiO ₂ (manufactured by Showa Titanium Co., Ltd.) are screened. Lamination was performed by printing, and post-treatment was performed with a TiCl ₄ aqueous solution to produce an FTO / TiO ₂ film (conductive support 1).

This FTO / TiO ₂ film was immersed in a 0.03M Cd (NO ₃ ) ₂ ethanol solution for 30 seconds in a glove bag under an inert gas atmosphere, and subsequently 0.03M selenide (Se ²⁻ ) ethanol. Immerse in the solution for 30 seconds. Then, it wash | cleaned in ethanol for 1 minute or more, the excess precursor was removed, and it dried. This dipping, washing, and drying process is repeated for 5 sets to grow CdSe quantum dots 23 on the titanium oxide layer 22, and then a surface stabilization treatment is performed using CdTe, whereby a CdSe-treated photoelectrode (photoconductor) Layer 2) was prepared.
A selenide (Se ²⁻ ) ethanol solution was prepared by adding 0.068 g NaBH ₄ (to a concentration of 0.060M) to a 0.030M SeO ₂ ethanol solution in an Ar or N ₂ atmosphere. Prepared.

The CdSe-treated photoelectrode was dipped in a dye solution using the metal complex dye of the present invention for 4 hours, adsorbed with the dye 21 on the photoelectrode, and this photoelectrode and counter electrode 4 (hexachloroplatinate 2-propanol on FTO glass) A solution (0.05M) was sprayed, heated at 400 ° C. for 20 minutes, and Pt was chemically precipitated, assembled with a 25 μm thick Surlyn (DuPont Co., Ltd.) ring sandwiched, and heat-dissolved. Sealed. Electrolyte using cobalt complex (0.75 M Co (o-phen) ₃ ²⁺ , 0.075 M Co (o-phen) ₃ ³⁺ , 0.20 M LiClO ₄ acetonitrile / ethylene carbonate (4: 6 / v: v) Solution) is injected into the gap 3 between the electrodes (between the photoelectrode and the counter electrode) through a hole previously formed on the surface on the counter electrode side, and then the hole is used with a binel (DuPont) sheet and a thin glass slide. Then, the dye-sensitized solar cell 10 was manufactured by closing with heat.
The cobalt complex added to the electrolyte was prepared by the method described in Chemical Communications, 46, 8788-8790 (2010).

  For the dye-sensitized solar cell thus produced, the initial photoelectric conversion efficiency and water resistance were evaluated in the same manner as in Example 1. As a result, it was confirmed that the metal complex dyes of the present invention can provide good performance and improvement effect.

Example 4
The dye solar sensitized solar cell was evaluated in the same manner as in Example 1 except that the coexisting dyes or coadsorbents shown in Table 9 and Table 10 below were used. The amount of the metal complex dye was maintained as described above as a total amount, and the coexisting dye was contained at 30 mol% of the whole dye. The coadsorbent was added in an amount of 20 mol per 1 mol of the total amount of the metal complex dye. In the following Tables 9 and 10, the improvement effect of the initial photoelectric conversion efficiency is shown by the following criteria.

A: An increase of 2% or more was observed A: An increase of 1% or more and less than 2% was observed B: An increase of 0% or more and less than 1% was observed C: A decrease in performance was observed

The maximum absorption wavelength of these dyes in a tetrabutylammonium hydroxide methanol solution is as follows.
S-4: 478 nm
R-3: 590 nm
S-5: 768 nm

  As is clear from the above results, it can be seen that the photoelectric conversion element of the present invention exhibits a remarkable improvement effect by coexisting a specific coexisting dye or coadsorbent.

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

41 Transparent electrode 42 Semiconductor electrode 43 Transparent conductive film 44 Substrate 45 Semiconductor layer 46 Light scattering layer 40 Photoelectrode 20 Dye-sensitized solar cell CE Counter electrode E Electrolyte S Spacer 51 Transparent substrate 52 Transparent conductive film 53 Barrier layer 54 N-type semiconductor electrode 55 p-type semiconductor layer 56 p-type semiconductor film 57 counter electrode 57a protrusion

Claims (15)

A photoelectric conversion element having a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer layer containing an electrolyte, and a counter electrode, wherein the photoreceptor layer carries a metal complex dye represented by the following formula (I) A photoelectric conversion element having the formed semiconductor fine particles.
M ¹ (LA) (LD) Z Formula ¹ (I)
In the formula (I), M ¹ represents a metal atom and Z ¹ represents a monodentate ligand. LA represents a tridentate ligand represented by the following formula (AL-1). LD represents a bidentate ligand represented by the following formula (DL-1).

In the formula (AL-1), Za, Zb and Zc each independently represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.
In the formula (DL-1), E represents a group represented by any of the following formulas (E-1) to (E-6). X represents an oxygen atom, a sulfur atom, a selenium atom, N (Ra), C (Rb) ₂ or Si (Rb) ₂ . Here, Ra and Rb each independently represents a hydrogen atom, an alkyl group or an aryl group. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group.

In formulas (E-1) to (E-5), R represents a halogen atom or an alkyl group that may be substituted with a halogen atom. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring. The photoelectric conversion element according to claim 1, wherein M ¹ is Ru. The photoelectric conversion element according to claim 1 or 2, wherein the LA is represented by the following formula (AL-2).

In Formula (AL-2), R ^{A1 to} R ^A3 each independently represent a hydrogen atom, an alkyl group, an alkynyl group, a heteroaryl group, an aryl group, or an acidic group. a1 and a3 each independently represent an integer of 0 to 4, and a2 represents an integer of 0 to 3. However, any of a1 to a3 is an integer of 1 or more, and at least one of R ^{A1 to} R ^A3 is an acidic group, and the acidic group is bonded to at least a pyridine ring. The photoelectric conversion element according to any one of claims 1 to 3, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).

In the formula (II), R ¹⁰ represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. The photoelectric conversion element according to any one of claims 1 to 4, wherein the metal complex dye represented by the formula (I) is represented by the following formula (III).

In the formula (III), Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.   The photoelectric conversion element according to claim 1, wherein a plurality of dyes are supported on the semiconductor fine particles.   Among the metal complex dyes supported on the semiconductor fine particles, at least one of the dyes other than the metal complex dye represented by the formula (I) has a maximum absorption wavelength in a tetrabutylammonium hydroxide methanol solution of 590 nm or more. The photoelectric conversion element according to claim 6.   The photoelectric conversion element according to claim 1, wherein a co-adsorbent having one or more acidic groups is further supported on the semiconductor fine particles. The photoelectric conversion element according to claim 8, wherein the co-adsorbent is represented by the following formula (CA).

In the formula (CA), R ^C1 represents a substituent having an acidic group. R ^C2 represents a substituent. lc represents an integer of 0 or more.   The dye-sensitized solar cell which comprises the photoelectric conversion element of any one of Claims 1-9. A metal complex dye represented by the following formula (I).
M ¹ (LA) (LD) Z Formula ¹ (I)
In the formula (I), M ¹ represents a metal atom and Z ¹ represents a monodentate ligand. LA represents a tridentate ligand represented by the following formula (AL-1). LD represents a bidentate ligand represented by the following formula (DL-1).

In the formula (AL-1), Za, Zb and Zc each independently represent a nonmetallic atom group necessary for forming a 5- or 6-membered ring. However, at least one of the rings formed by Za, Zb and Zc has an acidic group.
In the formula (DL-1), E represents a group represented by any of the following formulas (E-1) to (E-6). X represents an oxygen atom, a sulfur atom, a selenium atom, N (Ra), C (Rb) ₂ or Si (Rb) ₂ . Here, Ra and Rb each independently represents a hydrogen atom, an alkyl group or an aryl group. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group.

In formulas (E-1) to (E-5), R represents a halogen atom or an alkyl group that may be substituted with a halogen atom. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring. The metal complex dye according to claim 11, wherein M ¹ is Ru. The metal complex dye according to claim 11 or 12, wherein the LA is represented by the following formula (AL-2).

In Formula (AL-2), R ^{A1 to} R ^A3 each independently represent a hydrogen atom, an alkyl group, an alkynyl group, a heteroaryl group, an aryl group, or an acidic group. a1 and a3 each independently represent an integer of 0 to 4, and a2 represents an integer of 0 to 3. However, any of a1 to a3 is an integer of 1 or more, and at least one of R ^{A1 to} R ^A3 is an acidic group, and the acidic group is bonded to at least a pyridine ring. The metal complex dye according to any one of claims 11 to 13, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).

In the formula (II), R ¹⁰ represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom. na represents 0 or 1. nb represents an integer of 1 to 3. However, the sum of na and nb is 2 or more. Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. The metal complex dye of any one of claims 11 to 14, wherein the metal complex dye represented by the formula (I) is represented by the following formula (III).

In the formula (III), Rc represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group or an amino group. R ^{A1 to} R ^A3 each independently represents a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group. However, at least one of R ^{A1 to} R ^A3 is an acidic group. Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group.

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