WO2014156953A1 - Photoelectric conversion element, dye-sensitized solar cell, and metal-complex dye used in same - Google Patents

Abstract

This metal-complex dye can be represented by formula (I). (I) M¹(LA)(LD)Z¹ In formula (I), M¹ represents a metal atom; Z¹ represents a monodentate ligand; LA represents a tridentate ligand that can be represented by formula (AL-1); LD represents a bidentate ligand that can be represented by formula (DL-1); R^A1 through R^A3 each represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or an acidic group; at least one of R^A1, R^A2, and R^A3 represents an acidic group; R¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom, or an aryl group; m1 represents an integer from 0 to 3; na represents either 0 or 1; and G represents a group that can be represented by formula (G-1) and exhibits a log P between 3.0 to 20.0, inclusive.

Description

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

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

Photoelectric conversion elements are used in various optical sensors, copiers, 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 conducted energetically. In particular, it was the research results of Graetzel, etc., Lausanne University of Technology, Switzerland. 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

N749 is often used as a terpyridyl pigment. The above-mentioned Patent Document 2 is an improvement of this. In these, although the improvement of photoelectric conversion efficiency was recognized, the room for improvement was left in durability, especially heat resistance.
In view of the present state of the present technical field, the present invention provides a photoelectric conversion element, a dye-sensitized solar cell, and a metal complex dye used therefor that can achieve both high photoelectric conversion efficiency and high heat durability. Objective. Furthermore, the present invention uses the above-described dye, achieves high photoelectric conversion efficiency, and has a high molar extinction coefficient ε and IPCE (Incident Photo-to-Current Efficiency) in the long wavelength region of the absorption spectrum, and dye enhancement. An object is to provide a solar cell and a metal complex dye used for them.

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 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), R ^A1 , R ^A2 and R ^A3 each independently represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group or an acidic group. However, at least one of R ^A1 , R ^A2 and R ^A3 is an acidic group.
In the formula (DL-1), R ¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom or an aryl group. m1 represents an integer of 0 to 3. na represents 0 or 1.
G represents a group represented by the following formula (G-1) and having Log P of 3.0 to 20.0. E represents a group represented by any of the following formulas (E-1) to (E-6).

In the formula (G-1), X represents an oxygen atom, a sulfur atom, N (R ² ), C (R ² ) (R ³ ), or Si (R ² ) (R ³ ). Here, R ² and R ³ each independently represents a hydrogen atom, an alkyl group or an aryl group. Ra, Rb and Rc each independently represents a hydrogen atom or a substituent. Ra and Rb, or Rb and Rc may be bonded to each other to form a ring.

In formulas (E-1) to (E-5), R represents a halogen atom, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
(2) In the formula (G-1), Ra and Rb are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group, an arylthio group, an amino group or an aryl group, and Rc is a hydrogen atom The photoelectric conversion device according to (1), which is an atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, or an amino group.
(3) The photoelectric conversion device according to (1), wherein in formula (G-1), Ra and Rb are a hydrogen atom, an alkyl group, an alkylthio group, or an amino group, and Rc is an aryl group.
(4) In the formula (G-1), Ra and Rb are chain alkoxy groups or aryloxy groups, and Rc is a hydrogen atom, alkyl group, alkenyl group, aryl group, heteroaryl group, alkoxy group, aryl The photoelectric conversion device according to (1), which is an oxy group, an alkylthio group, an arylthio group, or an amino group.
(5) The photoelectric conversion element according to any one of (1) to (4), wherein M ¹ is Ru.
(6) The photoelectric conversion element according to any one of (1) to (5), wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).

In formula ^{(II), R A1 ~ R} A3 have the same meanings as ^R A1 ^{~ R A3} in the formula (AL-1). Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. R ¹⁰ represents a hydrogen atom, an aryl group, a heterocyclic group or an alkyl group which may be substituted with a halogen atom. X and Ra to Rc have the same meanings as X and Ra to Rc in formula (G-1). na has the same meaning as na in formula (DL-1).
(7) The photoelectric conversion element according to any one of (1) to (6), wherein a plurality of dyes are supported on the semiconductor fine particles.
(8) The photoelectric conversion device according to any one of (1) to (7), wherein the semiconductor fine particles are further supported with a co-adsorbent having one or more acidic groups.
(9) The photoelectric conversion element according to (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.
(10) A dye-sensitized solar cell comprising 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), R ^A1 , R ^A2 and R ^A3 each independently represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group or an acidic group. However, at least one of R ^A1 , R ^A2 and R ^A3 is an acidic group.
In the formula (DL-1), R ¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom or an aryl group. m1 represents an integer of 0 to 3. na represents 0 or 1.
G represents a group represented by the following formula (G-1) and having Log P of 3.0 to 20.0. E represents a group represented by any of the following formulas (E-1) to (E-6).

In the formula (G-1), X represents an oxygen atom, a sulfur atom, N (R ² ), C (R ² ) (R ³ ), or Si (R ² ) (R ³ ). Here, R ² and R ³ each independently represents a hydrogen atom, an alkyl group or an aryl group. Ra, Rb and Rc each independently represents a hydrogen atom or a substituent. Ra and Rb, or Rb and Rc may be bonded to each other to form a ring.

In formulas (E-1) to (E-5), R represents a halogen atom, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
(12) In the formula (G-1), Ra and Rb are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group, an arylthio group, an amino group or an aryl group, and Rc is a hydrogen atom The metal complex dye according to (11), which is an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group or an amino group.
(13) The metal complex dye according to (11), wherein in formula (G-1), Ra and Rb are a hydrogen atom, an alkyl group, an alkylthio group or an amino group, and Rc is an aryl group.
(14) In the formula (G-1), Ra and Rb are chain alkoxy groups or aryloxy groups, and Rc is a hydrogen atom, alkyl group, alkenyl group, aryl group, heteroaryl group, alkoxy group, aryl The metal complex dye according to (11), which is an oxy group, an alkylthio group, an arylthio group, or an amino 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 (II).

In formula ^{(II), R A1 ~ R} A3 have the same meanings as ^R A1 ^{~ R A3} in the formula (AL-1). Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. R ¹⁰ represents a hydrogen atom, an aryl group, a heterocyclic group or an alkyl group which may be substituted with a halogen atom. X and Ra to Rc have the same meanings as X and Ra to Rc in formula (G-1). na has the same meaning as na in formula (DL-1).

In the present specification, the term “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.

The photoelectric conversion element, the dye-sensitized solar cell of the present invention, and the metal complex dye used therein can improve the molar extinction coefficient ε in the long wavelength region of the absorption spectrum, and can realize high heat resistance. Furthermore, according to the present invention, high photoelectric conversion efficiency is achieved, and excellent device performance with high ε and IPCE (incident photo-to-current efficiency) in a long wavelength region is exhibited.

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.

The metal complex dye of the present invention has a structure in which a tridentate ligand containing nitrogen and a bidentate ligand containing nitrogen are coordinated with a central metal, and thereby, high photoelectric conversion of a photoelectric conversion element. Achieves both efficiency and high heat resistance.
This reason includes unclear points, but can be explained as follows, including estimation.
The metal complex dye of the present invention has a group having a high LogP value. The LogP value is known as an index of the fat solubility of the compound. By having a group having a high LogP value, the lipid solubility is improved and the hydrophobicity is improved, and the deterioration of the photoelectric conversion element due to moisture is suppressed. In particular, when the structure has a thiophene ring, the one-electron oxidation state is stabilized by delocalization, so that an effect of further improving durability can be expected.
Below, this invention is demonstrated in detail based on the preferable embodiment.

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

In the present embodiment, the light receiving electrode 5 includes a photosensitive layer 2 including a conductive support 1 and semiconductor fine particles 22 to 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. Electrons on the electrodes work in the external circuit 6 and return to the photoreceptor layer 2 where the oxidant and electrolyte of the dye (metal complex dye) 21 are present via the counter electrode 4 to work as a solar cell.
The upper and lower sides of the photoelectric conversion element do not need to be defined in particular, but in this specification, based on what is illustrated, the support body serving as the light receiving side with the counter electrode 4 side as the upper (top) direction The side of 1 is the lower (bottom) direction.

In the present invention, as a material used for the photoelectric conversion element or the dye-sensitized solar cell and a method for manufacturing each member, a manufacturing method usually used for the photoelectric conversion element or the dye-sensitized solar cell may be employed.
For example, US Pat. No. 4,927,721, US Pat. No. 4,684,537, US Pat. No. 5,084,365, US Pat. No. 5,350, No. 644, U.S. Pat. No. 5,463,057, U.S. Pat. No. 5,525,440, JP-A-7-249790, JP-A-2004-220974, JP-A-2008-135197. Reference can be made to the official gazette.
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 sensitizing dye containing the metal complex dye of the present invention described below.
Some sensitizing dyes may be dissociated in the electrolyte. The photoreceptor layer is designed according to the purpose, and may be a single layer structure or a multilayer structure. In this invention, since it contains the semiconductor fine particle which the metal complex dye of this invention adsorb | sucked, when using it as a dye-sensitized solar cell, high photoelectric conversion efficiency can be obtained.

[Metal Complex Dye Represented by Formula (I)]
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 tetracoordination or hexacoordination, and more preferably Ru, Fe, Os, Cu, W, Cr, Mo, Ni, Pd, Pt, Co, Ir, Rh, Re, Mn or Zn. Particularly preferred is Ru, Os, Zn or Cu, and most preferred is Ru.

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

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

At least one of R ^A1 to R ^A3 is an acidic group, preferably two are acidic groups, and more preferably three are acidic groups.

・ 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 or a group having this is preferred. Further, the acidic group may take a form of releasing a proton and dissociating, or may be a salt. Although it does not specifically limit as a counter ion when becoming a salt, For example, the example of the positive ion in the following counter ion CI is mentioned. In the present invention, the acidic group may be a group bonded via a linking group. For example, a carboxyvinylene group, a dicarboxyvinylene group, a cyanocarboxyvinylene group, a carboxyphenyl group, and the like can be given as preferable acidic groups. In addition, the acidic group mentioned here and its preferable range may be called acidic group Ac.

Specific examples of LA are shown below, but the present invention is not construed as being limited thereto.

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

・ R ¹
R ¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom or an aryl group. Each of these groups is preferably a corresponding group exemplified in the substituent T described later.

・ M1
m1 represents an integer of 0 to 3.
When m1 is 2 or more, the plurality of R ¹ may be the same or different and may be bonded to each other to form a ring. m1 is preferably 0 or 1, and more preferably 0.

・ 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, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group.
Each of these groups is preferably a group corresponding to the substituent T described later.
Among them, R is preferably a halogen atom or an alkyl group which may be substituted with a halogen atom. The alkyl group substituted with a halogen atom is preferably an alkyl group substituted with a fluorine atom. Further, from the number of halogen atom substitutions, a perhalogenated alkyl group is preferable, a perfluoroalkyl group is more preferable, and a perfluoromethyl group is particularly preferable.

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.
In addition, * shows the coupling | bonding position couple | bonded with 2-position of a pyridine ring.

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

・ Na
na represents 0 or 1. na is preferably 1.

・ G
G represents a group represented by the following formula (G-1) and having Log P of 3.0 to 20.0.

In the formula (G-1), X represents an oxygen atom, a sulfur atom, N (R ² ), C (R ² ) (R ³ ), or Si (R ² ) (R ³ ). Here, R ² and R ³ each independently represents a hydrogen atom, an alkyl group or an aryl group. Ra, Rb and Rc each independently represents a hydrogen atom or a substituent. Ra and Rb, or Rb and Rc may be bonded to each other to form a ring. The formed ring is preferably a 5- or 6-membered ring, and may be a saturated hydrocarbon ring, an unsaturated hydrocarbon ring, a saturated hetero ring or an unsaturated hetero ring, and may be an aromatic ring or a heteroaromatic ring. Preferred rings include a cyclohexane ring, a dioxane ring, a dithiodioxane ring, a benzene ring and the like.
X is preferably an oxygen atom, a sulfur atom, N (R ² ), or C (R ² ) (R ³ ), more preferably an oxygen atom, a sulfur atom, or C (R ² ) (R ³ ), and particularly a sulfur atom. preferable.

G has a LogP value of 3.0 to 20.0.
LogP means the common logarithm of the partition coefficient P (Partition Coefficient), and quantitatively shows how a chemical substance is distributed in the equilibrium of a two-phase system of oil (generally 1-octanol) and water. It is a physical property value expressed as a numerical value, and is expressed by the following formula.

LogP = Log (C _oil / C _water )

In the above formula, C _oil represents the molar concentration in the _oil phase, and C _water represents the molar concentration in the aqueous phase. The oil solubility increases when the LogP value increases to a positive value across 0, and the water solubility increases when the absolute value increases with a negative value. LogP has a negative correlation with the water solubility of chemical substances, and is widely used as a parameter for estimating hydrophilicity and hydrophobicity. In principle, it is actually measured by a distribution experiment in view of its definition, but the experiment itself is quite troublesome, so estimation from the structural formula is an effective means.

For this reason, the Log P value estimated by calculation is frequently used.
In the present invention, the LogP value is determined by ChemDrawProver., Manufactured by CambridgeSoft. It is a value calculated by 12.0. The Log P value of G is 3.0 to 20.0, preferably 3.5 to 15.0, more preferably 4.0 to 14.0, still more preferably 4.2 to 12.0. .3 to 10.0 is particularly preferable, and 4.4 to 9.0 is most preferable.

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).

In formula ^{(II), R A1 ~ R} A3 have the same meanings as ^R A1 ^{~ R A3} in the formula (AL-1), 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. R ¹⁰ represents a hydrogen atom, an aryl group, a heterocyclic group, or an alkyl group that may be substituted with a halogen atom. X and Ra to Rc have the same meanings as X and Ra to Rc in formula (G-1), and the preferred ranges are also the same. na has the same meaning as na in formula (DL-1), and the preferred range is also the same. A common description will be given below.

The metal complex dye represented by the formula (I) and the metal complex dye represented by the formula (II) have a group represented by the formula (G-1) in common.

The group represented by the formula (G-1) is preferably any one of the following embodiments A to C, more preferably embodiment A or embodiment B, from the viewpoint of photoelectric conversion efficiency and durability. More preferably, it is embodiment A.

<Aspect A>
Ra and Rb are each independently a hydrogen atom, an alkyl group, an amino group, an alkylthio group, an arylthio group, an alkenyl group, an alkynyl group, or an aryl group, and Rc is a hydrogen atom, an alkyl group, an alkylamino group, A group, an arylamino group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a heteroaryl group, an alkenyl group, or an alkynyl group. However, when na is 0 and both Ra and Rb are hydrogen atoms, Rc is a hydrogen atom, alkylamino group, arylamino group, alkoxy group, aryloxy group, alkylthio group, arylthio group, heteroaryl group, alkenyl. Group or an alkynyl group.

Ra and Rb are preferably each independently a hydrogen atom, an alkyl group, an alkylthio group, an arylthio group, an alkenyl group, an alkynyl group, or an aryl group, and a hydrogen atom, an alkyl group, an alkylthio group, an arylthio group, or an aryl group. More preferably, it is a hydrogen atom, an alkyl group, an alkylthio group, or an aryl group.

Rc is preferably a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkenyl group or a heteroaryl group, and a hydrogen atom, an alkyl group, an alkylthio group, an arylthio group, an alkenyl group or a heteroaryl group It is more preferably a hydrogen atom, an alkyl group, an alkylthio group, an arylthio group, or a heteroaryl group, and particularly preferably a hydrogen atom, an alkyl group, an alkylthio group, or a heteroaryl group. When Ra is a substituent, Rb is preferably a hydrogen atom, Rc is preferably a hydrogen atom, an alkoxy group, an alkylthio group, an arylthio group or a heteroaryl group, and is a hydrogen atom or a heteroaryl group. Is more preferable. When Rb is the aforementioned substituent, Ra and Rc are preferably hydrogen atoms.

Here, the heterocycle of the heteroaryl group is preferably a 5-membered aromatic ring, more preferably a thiophene ring, a furan ring, or a pyrrole ring, and most preferably a thiophene ring.

A specific example of-(CH = CH) na-G is shown below together with a specific example of G in Aspect A. However, the scope of the present invention is not limited thereby.
When na is 0, it is bonded to the pyridine ring substituted with E at the position of *, and when na is 1, it is bonded to — (CH═CH) — at the position of *.

<Aspect B>
Ra and Rb are any one of a hydrogen atom, an alkyl group, an amino group, an alkylthio group, and an arylthio group, and Rc is an aryl group. Ra and Rb are preferably a hydrogen atom, an alkyl group, an alkylthio group, or an arylthio group, and Rc is preferably an aryl group, Ra and Rb are either a hydrogen atom or an alkyl group, and More preferably, Rc is an aryl group.

The aryl group of Rc is a phenyl group which may have a substituent, an aryl group in which a 5- or 6-membered cycloalkane, a 5- or 6-membered heterocyclic ring is condensed, such as a fluorene ring group or a carbazole ring Groups. The substituent is preferably a halogen atom or an alkyl group, and the alkyl group is preferably an alkyl group substituted with a fluorine atom (for example, a trifluoromethyl group).

A specific example of-(CH = CH) na-G is shown below together with a specific example of G in Aspect B. However, the scope of the present invention is not limited thereby.
When na is 0, it is bonded to the pyridine ring substituted with E at the position of *, and when na is 1, it is bonded to — (CH═CH) — at the position of *.

<Aspect C>
Ra and Rb are chain alkoxy groups or aryloxy groups, and Rc is a hydrogen atom, alkyl group, alkylamino group, arylamino group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkenyl group, Either an aryl group or a heteroaryl group. The chain-like alkoxy group or aryloxy group in Ra and Rb is a substituted or unsubstituted linear or branched alkoxy group having 5 to 30 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. It is preferably a substituted or unsubstituted linear or branched alkoxy group having 5 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, more preferably a substituted or unsubstituted carbon number. A straight chain or branched alkoxy group having 5 to 15 or a substituted or unsubstituted aryloxy group having 6 to 15 carbon atoms is more preferable.

A specific example of-(CH = CH) na-G is shown below together with a specific example of G in Aspect C. However, the scope of the present invention is not limited thereby.
When na is 0, it is bonded to the pyridine ring substituted with E at the position of *, and when na is 1, it is bonded to — (CH═CH) — at the position of *.

G is also preferably represented by any of the following formulas (G1-1) to (G1-5).

In the formulas (G1-1) to (G1-5), X, Ra, Rb, Rc and na have the same meanings as X, Ra, Rb, Rc and na in the formula (G-1), and preferred ranges are also the same. is there. Rd and Re are synonymous with Ra and Rb, and their preferred ranges are also the same. Ra 'represents a substituent. The substituent is preferably a preferable substituent in Ra.

Of these, (G1-1), (G1-3), (G1-4), and (G1-5) are preferred, and (G1-1) and (G1-4) are more preferred.

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

The specific example of aspect A is shown below.
In addition, the position where — (CH═CH) na-G is bonded to the pyridine ring substituted with E is described as “substitution position of G-containing group”.

Specific examples of aspect B are shown below.

Specific examples of aspect C are shown below.

The ligand represented by the formula (DL-1) is Chem. Commun. , 2009, 5844-5846.

<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.

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.

The metal complex dye represented by the formula (I) of the present invention is disclosed in US Patent Application Publication No. 2010 / 0258175A1, Japanese Patent No. 4298799, Angew. Chem. Int. Ed. , 2011, 50, 2054-2058, Chem. Commun. , 2009, 5844-5846, the method described in the reference cited in the literature, or a method analogous thereto.

In the metal complex dye of the present invention, 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.

In the present invention, the metal complex dye of the present invention may be used in combination with another dye.
Examples of the dye used in combination include Ru complex dyes described in JP-A-7-500630 (particularly the dyes synthesized in Examples 1 to 19 on page 5, lower left column, line 5 to page 7, upper right column, line 7). ), Ru complex dyes described in JP-T-2002-512729 (especially dyes synthesized in Examples 1 to 16 from the third line to the 29th page and the 23rd line from the bottom of page 20), JP-A-2001- Ru complex dyes described in Japanese Patent No. 59062 (particularly dyes described in paragraphs 0087 to 0104), Ru complex dyes described in Japanese Patent Application Laid-Open No. 2001-6760 (particularly dyes described in paragraph numbers 0093 to 0102), Ru complex dyes described in JP-A No. 2001-253894 (especially dyes described in paragraph Nos. 0009 to 0010), Ru complex dyes described in JP-A No. 2003-212851 (particularly colors described in paragraph No. 0005) ), Ru complex dyes described in International Publication No. 2007/91525 pamphlet (particularly the dye described in [0067]), Ru complex dyes described in Japanese Patent Application Laid-Open No. 2001-291534 (particularly in paragraphs 0120 to 0144). Described), Ru complex dyes described in JP2012-012570A (in particular, dyes described in paragraph Nos. 0095 to 0103), squarylium cyanine dyes described in JP11-214730A (particularly paragraph numbers). Dyes described in JP-A-2012-144688, squarylium cyanine dyes described in JP 2012-144688 (in particular, the dyes described in paragraphs 0039-0046 and paragraphs 0054-0060), JP-A 2012-84503 The squarylium cyanine dyes described (particularly paragraphs 0066-00 6), organic dyes described in JP-A-2004-063274 (especially dyes described in paragraphs 0017 to 0021), and organic dyes described in JP-A-2005-123033 (particularly paragraphs). Nos. 0021 to 0028), organic dyes described in JP-A No. 2007-287694 (particularly dyes described in paragraphs 0091 to 0096), organic dyes described in JP-A No. 2008-71648 (particularly) , Paragraphs 0030 to 0034), organic dyes described in WO 2007/119525 pamphlet (particularly, the dye described in [0024]), Angew. Chem. Int. Ed. , 49, 1-5 (2010), etc., Angew. Chem. Int. Ed. , 46, 8358 (2007), and the like.
The dye used in combination is preferably a Ru complex dye, a squarylium cyanine dye, or an organic dye.

When the metal complex dye of the present invention is used in combination with another dye, the ratio of the mass of the metal complex dye of the present invention to the mass of the other dye is preferably 95/5 to 10/90, and 95/5 to 50/50. Is more preferable, 95/5 to 60/40 is further preferable, 95/5 to 65/35 is particularly preferable, and 95/5 to 70/30 is most preferable.

-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 be provided with a light management function. For example, an antireflection film in which high refractive films and low refractive index oxide films described in JP-A-2003-123859 are alternately laminated Or 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. The light transmittance of the conductive support is 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 the 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. The metal chalcogenide is preferably titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, or tantalum or an oxide thereof, cadmium sulfide, cadmium selenide, or the like. Can be mentioned. Preferred perovskites include strontium titanate and calcium titanate. Of these, titanium oxide (titania), zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

Examples of the crystal structure of titania include anatase type, brookite type, and rutile type, and anatase type and brookite type are preferable. Titania nanotubes, titania nanowires, or nanorods may be mixed with titania microparticles or used as semiconductor electrodes.

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.

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 reverse current due to direct contact between the electrolyte and the electrode. 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. The preferred thickness of the photoreceptor layer, which is a semiconductor layer, varies depending on the use of the device, but is typically 0.1 to 100 μm. When used as a dye-sensitized solar cell, the thickness of the photoreceptor layer is preferably 1 to 50 μm, and more preferably 3 to 30 μm. 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 semiconductor fine particles per 1 m ² of 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, and 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-t-butylpyridine, polyvinylpyridine) and the like. In the case of a liquid, these may be used as they are, or may be used after being dissolved in an organic solvent.

In the photoelectric conversion element (for example, the photoelectric conversion element 10) and the dye-sensitized solar cell (for example, the 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 electrolytes include a liquid electrolyte in which a redox couple is dissolved in an organic solvent, an electrolyte in which a liquid in which a redox couple is dissolved in an organic solvent is impregnated in a polymer matrix (so-called gel electrolyte), a molten salt containing the redox couple, and the like Is mentioned. 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. As a solvent for the liquid electrolyte, 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) Combination, combination of alkyl viologen (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and its reduced form, combination of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and oxidized form 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 or a combination of divalent and trivalent cobalt complexes is preferable as the redox pair.

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 an integer of 0-6. CI represents a counter ion when a counter ion is required to neutralize the charge.

CI represents a counter ion when a counter ion is required to neutralize the charge.
In general, whether a complex is a cation or an anion or has a net ionic charge depends on the metal, ligand and substituent in the complex.
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, a halogen anion (eg, fluoride ion, chloride ion, bromide ion, iodide ion, etc.), substituted aryl sulfonate ion (eg, p-toluene sulfonate ion, p-chlorobenzene sulfonate ion, etc.), aryl disulfone Acid ions (for example, 1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion, etc.), alkyl sulfate ions (for example, methyl sulfate ion), sulfate ions, thiocyanate ions Perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, picrate ion, acetate ion, trifluoromethanesulfonate ion and the like. Furthermore, as the charge balance counter ion, an ionic polymer or another complex having a charge opposite to that of the complex may be used, and a metal complex ion (for example, bisbenzene-1,2-dithiolatonickel (III)) can also be used. is there.

In the metal complex dye of the present invention, CI may be contained if necessary.

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 among these, a halogen ion is preferable.

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

R ^LC1 to R ^LC11 each independently represents 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 0-2.

In the formulas (LC-1) to (LC-4), ^examples of the substituent in 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.

The organic solvent that dissolves the redox couple is preferably an aprotic polar solvent (eg acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3-methyloxazolidinone, etc.). . 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. In addition, γ-butyrolactone may be included in the electrolyte, which increases the diffusion efficiency of iodide ions and improves the conversion efficiency.

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

Also, in order to improve the photoelectric conversion efficiency, a method of controlling the moisture of the electrolytic solution may be taken. 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.

A molten salt 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 a molten salt 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 made pseudo-solid by adding a gelling agent to an electrolyte solution composed of an electrolyte and a solvent to cause gelation (the pseudo-solid electrolyte is also referred to as “pseudo-solid electrolyte” hereinafter). 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 made of a specific acidic compound and a basic compound, 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.
The matrix polymer is preferably a polymer having a nitrogen-containing heterocycle in the repeating unit of the main chain or side chain, a crosslinked product obtained by reacting these nitrogen-containing heterocycle with an electrophilic compound, or a polymer having a triazine structure , Polymer having ureido structure, liquid crystal compound-containing polymer, ether-bonded polymer, polyvinylidene fluoride, methacrylate / acrylate, thermosetting resin, crosslinked polysiloxane, polyvinyl alcohol (PVA), polyalkylene glycol And inclusion compounds such as dextrin, oxygen-containing or sulfur-containing polymers, and natural polymers. An alkali swelling polymer, a polymer having a compound capable of forming a charge transfer complex between a cation moiety and iodine in one polymer, and the like may be added thereto.

As the matrix polymer, 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, a solvent having a specific dielectric constant, and the like. The liquid electrolyte solution may be held in a solid electrolyte membrane or pores, and preferred methods thereof 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, or polysilane, a spiro compound in which two rings share a tetrahedral structure such as C or Si, and an aromatic such as triarylamine. Group amine derivatives, triphenylene derivatives, nitrogen-containing heterocyclic derivatives, and liquid crystalline cyano derivatives.

Since the redox couple is 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.

[Co-adsorbent]
In the photoelectric conversion element of this invention, it is preferable to use a coadsorbent with the metal complex dye of this invention or the pigment | dye used together if necessary. As such a co-adsorbent, a co-adsorbent having at least one acidic group (preferably a carboxy group or a salt 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 the acidic group and Ac in said Formula (I), and its preferable range is also the same.
Among these, R ^C1 is preferably a carboxy group or an alkyl group substituted with a sulfo group or a salt thereof, —CH (CH ₃ ) CH ₂ CH ₂ CO ₂ H, —CH (CH ₃ ) CH ₂ CH ₂ More preferred is CONHCH 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. .

lc represents an integer of 0 or more, and when lc is 2 or more, a plurality of ^RC2s may be the same as or different from each other. lc is preferably 2-4.

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

The co-adsorbent of 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 the coadsorbent used is not particularly limited, but is preferably 1 to 200 mol, more preferably 10 to 150 mol, and particularly preferably 20 to 50 mol with respect to 1 mol of the dye. Is effectively expressed, and is preferable.

<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 or 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 it is described only 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 groups.
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, 2-propynyl, 2-butynyl, phenylethynyl, etc.) A cycloalkyl group (preferably having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), a cycloalkenyl group (preferably having 5 to 20 carbon atoms such as cyclopentenyl, cyclohexenyl, etc. ), Aryl groups (preferably having 6 to 26 carbon atoms, eg , Phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, etc.), heterocyclic group (preferably having 2 to 20 carbon atoms and having at least one oxygen atom, sulfur atom, nitrogen atom) More preferred are membered or six-membered heterocyclic groups such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2-thiazolyl, 2-oxazolyl, etc., alkoxy groups (preferably having 1 carbon atom) -20, for example, methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), alkenyloxy groups (preferably having 2-20 carbon atoms, eg, vinyloxy, allyloxy, etc.), alkynyloxy groups (preferably having 2-20 carbon atoms). And, for example, 2-propynyloxy, 4-butynyloxy, etc.), cycloalkyloxy A group (preferably having 3 to 20 carbon atoms such as cyclopropyloxy, cyclopentyloxy, cyclohexyloxy, 4-methylcyclohexyloxy, etc.), an aryloxy group (preferably having 6 to 26 carbon atoms such as phenoxy, 1- Naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), heterocyclic oxy groups (eg, imidazolyloxy, benzoimidazolyloxy, thiazolyloxy, benzothiazolyloxy, triazinyloxy, purinyloxy),

An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.), a cycloalkoxycarbonyl group (preferably having 4 to 20 carbon atoms such as 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 an 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 an alkyl, cycloalkyl or aryl sulfonamide having 0 to 20 carbon atoms) Groups such as methanesulfonamide, benzenesulfonamide, N-methylmethanesulfonamide, N-cyclohexylsulfonamide, N-ethylbenzenesulfonamide, etc., alkylthio groups (preferably having 1 to 20 carbon atoms, eg, methylthio , Ethylthio, isopropylthio, benzylthio, etc.), cycloalkylthio groups (preferably having 3 to 20 carbon atoms, such as cyclopropylthio, cyclopentylthio, cyclohexylthio, 4-methylcyclohexylthio) Etc.), arylthio groups (preferably having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), alkyl, cycloalkyl or arylsulfonyl groups (preferably having carbon numbers) 1-20, for example, methylsulfonyl, ethylsulfonyl, cyclohexylsulfonyl, benzenesulfonyl, etc.),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted by 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.), 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. Also, JP 2004-152613 A, JP 2000-90989 A, JP 2003-217688 A, JP 2002-367686 A, JP 2003-323818 A, JP 2001-43907 A, 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-2002-280857, JP-A-2001-2001. No. 273937, JP-A 2000-285 77 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 the present invention, it is preferable to produce a dye adsorption electrode using a dye solution containing the metal complex dye of the present 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 particularly 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 the present invention, the metal complex dye of the present invention is preferably contained in an amount of 0.001 to 0.1% by mass.

The water content of the dye solution is particularly preferably adjusted. Therefore, in the present invention, the water content (content ratio) is preferably adjusted to 0 to 0.1% by mass.
Similarly, the adjustment of the water content of the electrolyte in the photoelectric conversion element or the dye-sensitized solar cell is also preferable in order to effectively exhibit the effect of the present invention. For this reason, the water content (content rate) of the electrolyte solution is It is preferable to adjust to 0 to 0.1% by 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 is not construed as being limited thereto.

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

(Synthesis of metal complex dye Ru-17A)
A metal complex dye Ru-17A 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 agitation was performed at 0 ° C. under 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, followed by stirring 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 under 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, 4.1 g of diisopropylamine and 30 ml of tetrahydrofuran were stirred 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 the mixture was stirred at 0 ° C. for 80 minutes, and then Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), 1992, # 11, p. A solution of 5.00 g of compound d-1-4 synthesized by the method described in 959-1963 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 5.0 g of compound d-1-5.

(Iv) Synthesis of compound d-1-6 4.9 g of compound d-1-5 and 4.1 g of PPTS (pyridinium paratoluenesulfonic acid) were added to 50 ml of toluene, and the mixture was 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 3.2 g of compound d-1-6.

(V) Synthesis of metal complex dye Ru-17A 1.22 g of compound d-1-7 and 1.62 g of compound d-1-6 were added to 150 ml of N, N-dimethylformamide, and the reaction was performed at 70 ° C. under a nitrogen atmosphere. For 3 hours. Next, 1.99 g of compound d-1-8 was added thereto, and the mixture was heated with stirring at 160 ° C. for 8 hours. Thereafter, 10.7 g of ammonium thiocyanate was added, and the mixture was 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, then added to a mixed solvent of 15 ml of tetrahydrofuran, 15 ml of methanol, and 40 ml of 1N aqueous sodium hydroxide solution, and stirred at an external temperature of 40 ° C. for 24 hours. The solution after the reaction was returned to room temperature, and the pH was adjusted to 3 by adding a 0.1 M solution of trifluoromethanesulfonic acid. The resulting precipitate was filtered to obtain 0.3 g of a metal complex dye Ru-17A.
The structure of the obtained metal complex dye Ru-17A was confirmed by MS measurement.
ESI-MS m / z = 1018 (M−H) ⁺

(Synthesis of dye Ru-31A)

Three 100 ml portions of 1.0 g of compound d-2-1, 2.4 g of compound d-2-2, compound S-Phos 0.4 g, tripotassium phosphate 5.5 g, tetrahydrofuran 10 ml, and methanol 5 ml The flask was placed and degassed. The atmosphere was replaced with nitrogen, 0.07 g of palladium acetate was added thereto, and the mixture was refluxed for 12 hours using an oil bath at 80 ° C. After the refluxed solution was returned to room temperature, distilled water was added thereto, and the reaction product was extracted with ethyl acetate. After the solvent was distilled off from the organic phase, purification was performed by silica gel column chromatography to obtain 1 g of compound d-2-3.
A metal complex dye Ru-31A was synthesized in the same manner as the metal complex dye Ru-17A except that compound d-1-1 was changed to compound d-2-3 in the synthesis of metal complex dye Ru-17A. did.
The structure of the obtained metal complex dye Ru-31A was confirmed by MS measurement.
ESI-MS m / z = 1070 (M−H) ⁺

(Vi) Synthesis of metal complex dye Ru-8B

Medicinal Chemistry letters, 2011, vol. 2, # 1, p. Compound d-3-2 was synthesized using the methods described in 2-6. Next, a metal complex dye Ru-8B was synthesized in the same manner as the metal complex dye Ru-17A except that the compound d-1-6 was changed to the compound d-3-2 in the synthesis of the metal complex dye Ru-17A. Was synthesized.
The structure of the obtained metal complex dye Ru-8B was confirmed by MS measurement.
ESI-MS m / z = 964 (M−H) ⁺

In the same manner as the synthesis of the metal complex dyes Ru-17A, Ru-31A, and Ru-8B, the metal complex dyes Ru-7A, Ru-8A, Ru-9A, Ru-18A, Ru-24A, Ru-29A, Ru- 30A, Ru-43A to Ru-49A, metal complex dyes Ru-1B, Ru-16B, and metal complex dyes Ru-1C were synthesized. The obtained metal complex dye was identified by ESI-MS.

The synthesized metal complex dyes are shown below.

The following metal complex dyes were used as comparative compounds.
The comparative compound (2) is a compound described in US Patent Application Publication No. 2010/0258175 (Cited document 2).

(Example 1)
[Preparation of dye-sensitized solar cell]
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 dye-sensitized solar cell 1 having a scale of 10 mm × 10 mm having the same configuration as that of the dye-sensitized solar cell 20 of FIG. 3 except that the lever 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.

(Preparation of paste)
(Paste A)
A titania slurry was prepared by putting spherical TiO ₂ particles (anatase, average particle size; 25 nm, hereinafter referred to as spherical TiO ₂ particles A) into a nitric acid solution and stirring. Next, a cellulosic binder was added to the titania slurry as a thickener and kneaded to prepare paste A.
(Paste 1)
A titania slurry was prepared by stirring spherical TiO ₂ particles A and spherical TiO ₂ particles (anatase, average particle size: 200 nm, hereinafter referred to as spherical TiO ₂ particles B) in a nitric acid solution. Next, a cellulose binder as a thickener was added to the titania slurry and kneaded to prepare paste 1 (mass of TiO ₂ particles A: mass of TiO ₂ particles B = 30: 70).
(Paste 2)
The paste A was mixed with rod-like TiO ₂ particles (anatase, diameter: 100 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles C), and the mass of the rod-like TiO ₂ particles C: the mass of the paste A = 30: 70 Paste 2 was prepared.

(Creation of semiconductor electrodes)
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 1 of the above screen printing and then dried. Then, it baked on the conditions of 450 degreeC in the air. Further, by repeating this screen printing and baking using the paste 2, a semiconductor electrode having the same configuration as the semiconductor electrode 42 shown in FIG. 2 (light-receiving surface area; 10 mm × 10 mm, layer) is formed on the SnO ₂ conductive film. Thickness: 10 μm, layer thickness of semiconductor layer: 6 μm, layer thickness of light scattering layer: 4 μm, content of rod-like TiO ₂ particles C contained in the light scattering layer; 30% by mass) (photoreceptor layer), A photoelectrode containing no dye was prepared.

(Dye adsorption)
Next, the pigment | dye was made to adsorb | suck to a semiconductor electrode (photoelectrode which does not contain pigment | dye) as follows. First, using a 1: 1 (volume ratio) mixture of anhydrous t-butanol and dimethylformamide dehydrated with magnesium ethoxide, the metal complex dyes shown in Table 2 below were used at a concentration of 3 × 10 ⁻⁴ mol / L. Furthermore, as a co-adsorbent, 20 mol of an equimolar mixture of chenodeoxycholic acid and cholic acid was added to 1 mol of the metal complex dye to prepare each dye solution. When the water content of this dye solution was measured by Karl Fischer titration, the water content was less than 0.01% by mass. Next, the semiconductor electrode is immersed in this solution at 40 ° C. for 10 hours, and then pulled up and dried at 50 ° C., thereby completing the photoelectrode 40 in which the dye is adsorbed to the semiconductor electrode by about 2 × 10 ⁻⁷ mol / cm ^2. It was.

(Assembling solar cells)
Next, a platinum electrode (thickness of Pt thin film; 100 nm) having the same shape and size as the above-mentioned photoelectrode 40 as the counter electrode CE, 0.1M iodine as an electrolyte, 0.05M lithium iodide, 4- An iodine-based redox acetonitrile solution containing 0.25M t-butylpyridine was prepared. Further, a DuPont spacer S (trade name: “Surlin”) having a shape corresponding to the size of the semiconductor electrode is prepared, the photoelectrode 40 and the counter electrode CE are opposed to each other through the spacer S, and the above-mentioned inside The outer periphery of the dye-sensitized solar cell and the electrolyte inlet were sealed and cured with Nagase Chemtech resin XNR-5516, and each dye was cured. Sensitized solar cells (sample numbers 101 to 119, c11 and c12) were completed. The performance of the obtained dye-sensitized solar cell was evaluated as follows.

<Evaluation of photoelectric conversion efficiency>
The battery characteristic test was performed by using a solar simulator (WAXS, WXS-85H), irradiating 1000 W / m ² pseudo-sunlight obtained from a xenon lamp through an AM1.5 filter, and using an IV tester. The measurement was performed by measuring the voltage characteristics and obtaining the photoelectric conversion efficiency. In comparison with the photoelectric conversion efficiency of the comparative compound (2), the following criteria were evaluated.

A: The photoelectric conversion efficiency is 1.05 times or more of the photoelectric conversion efficiency of the comparative compound (2) B: The photoelectric conversion efficiency is 1.01 times or more and less than 1.05 times the photoelectric conversion efficiency of the comparative compound (2) C: Photoelectric Conversion efficiency is less than 1.01 times the photoelectric conversion efficiency of comparative compound (2)

<Evaluation of thermal degradation>
The produced dye-sensitized solar cell was put into a 40 degreeC thermostat and the heat test was done. With respect to the dye-sensitized solar cell before the heat test and the dye-sensitized solar cell after 12 hours of the heat test, the current value was measured to evaluate the thermal deterioration rate. The thermal deterioration rate was calculated by multiplying the value obtained by dividing the decrease in the current value before and after the heat resistance test by the current value before the heat resistance test by 100. The obtained thermal degradation rate was compared with the thermal degradation rate of the comparative compound (2) and evaluated according to the following criteria.

A: Thermal degradation rate is less than 0.9 times the thermal degradation rate of the comparative compound (2) B: Thermal degradation rate is 0.9 times or more and less than 1 times the thermal degradation rate of the comparative compound (2) C: Thermal degradation rate Is more than 1 times the thermal degradation rate of the comparative compound (2)

In Table 2 below, it is shown as thermal degradation.

<Heat cycle test>
The prepared dye-sensitized solar cell was alternately put into a −10 ° C. freezer and a 40 ° C. constant temperature bath every 2 hours, and cooling and heating were repeated to conduct a heat cycle test. About the dye-sensitized solar cell before a heat cycle test, and the dye-sensitized solar cell 24 hours after a heat cycle test, the electric current value was measured and the deterioration rate was evaluated. The deterioration rate was calculated by multiplying 100 by the value obtained by dividing the decrease in the current value before and after the heat cycle test by the current value before the heat cycle test. The obtained deterioration rate was compared with the deterioration rate of the comparative compound (1) and evaluated according to the following criteria.

A: The deterioration rate is less than 0.9 times the deterioration rate of the comparative compound (1) B: The deterioration rate is 0.9 times or more and less than 1 time the deterioration rate of the comparative compound (1) C: The deterioration rate is the comparative compound (1 ) Degradation rate of 1) or more

Table 2 below shows the heat cycle.

As is clear from the above results, the dye-sensitized solar cells each including the photoelectric conversion element using the metal complex dye of the present invention are excellent in photoelectric conversion efficiency, are not easily deteriorated by heat, and have excellent battery characteristics. I understand that.
In the comparative compound (1), the Log P value of G is 2.94, and the Log P value of G in the comparative compound (2) is 3.0 or more, but the structure of G is represented by the formula ( It does not have the structure represented by G-1).
As is clear from this, the structure of G in the metal complex dye of the present invention and the Log P value of G in the range of 3.0 to 20.0 improve the photoelectric conversion efficiency and the heat deterioration resistance. It can be seen that it plays an important role.

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

Claims (15)

1. 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), R ^A1 , R ^A2 and R ^A3 each independently represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group or an acidic group. However, at least one of R ^A1 , R ^A2 and R ^A3 is an acidic group.
   In the formula (DL-1), R ¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom or an aryl group. m1 represents an integer of 0 to 3. na represents 0 or 1.
   G represents a group represented by the following formula (G-1) and having Log P of 3.0 to 20.0. E represents a group represented by any of the following formulas (E-1) to (E-6).
   

   

   In the formula (G-1), X represents an oxygen atom, a sulfur atom, N (R ² ), C (R ² ) (R ³ ), or Si (R ² ) (R ³ ). Here, R ² and R ³ each independently represents a hydrogen atom, an alkyl group or an aryl group. Ra, Rb and Rc each independently represents a hydrogen atom or a substituent. Ra and Rb, or Rb and Rc may be bonded to each other to form a ring.
   

   

   In formulas (E-1) to (E-5), R represents a halogen atom, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
2. In the formula (G-1), Ra and Rb are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group, an arylthio group, an amino group or an aryl group, and Rc is a hydrogen atom, an alkyl group The photoelectric conversion device according to claim 1, which is a group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, or an amino group.
3. The photoelectric conversion device according to claim 1, wherein, in the formula (G-1), Ra and Rb are a hydrogen atom, an alkyl group, an alkylthio group, or an amino group, and Rc is an aryl group.
4. In the formula (G-1), Ra and Rb are chain alkoxy groups or aryloxy groups, and Rc is a hydrogen atom, alkyl group, alkenyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group The photoelectric conversion element according to claim 1, which is an alkylthio group, an arylthio group, or an amino group.
5. The photoelectric conversion element according to any one of claims 1 to 4, wherein the M ¹ is Ru.
6. The photoelectric conversion element according to any one of claims 1 to 5, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).
   

   

   In formula ^{(II), R A1 ~ R} A3 have the same meanings as ^R A1 ^{~ R A3} in the formula (AL-1). Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. R ¹⁰ represents a hydrogen atom, an aryl group, a heterocyclic group or an alkyl group which may be substituted with a halogen atom. X and Ra to Rc have the same meanings as X and Ra to Rc in formula (G-1). na has the same meaning as na in formula (DL-1).
7. The photoelectric conversion element according to any one of claims 1 to 6, wherein a plurality of dyes are supported on the semiconductor fine particles.
8. The photoelectric conversion element according to any one of claims 1 to 7, wherein a co-adsorbent having one or more acidic groups is further supported on the semiconductor fine particles.
9. 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.
10. A dye-sensitized solar cell comprising the photoelectric conversion device according to any one of claims 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), R ^A1 , R ^A2 and R ^A3 each independently represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group or an acidic group. However, at least one of R ^A1 , R ^A2 and R ^A3 is an acidic group.
    In the formula (DL-1), R ¹ represents an alkyl group, an alkylthio group, an alkoxy group, a halogen atom or an aryl group. m1 represents an integer of 0 to 3. na represents 0 or 1.
    G represents a group represented by the following formula (G-1) and having Log P of 3.0 to 20.0. E represents a group represented by any of the following formulas (E-1) to (E-6).
    

    

    In the formula (G-1), X represents an oxygen atom, a sulfur atom, N (R ² ), C (R ² ) (R ³ ), or Si (R ² ) (R ³ ). Here, R ² and R ³ each independently represents a hydrogen atom, an alkyl group or an aryl group. Ra, Rb and Rc each independently represents a hydrogen atom or a substituent. Ra and Rb, or Rb and Rc may be bonded to each other to form a ring.
    

    

    In formulas (E-1) to (E-5), R represents a halogen atom, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group. m represents an integer of 0 or more. Here, * indicates a bonding position for bonding to the 2-position of the pyridine ring.
12. In the formula (G-1), Ra and Rb are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkylthio group, an arylthio group, an amino group or an aryl group, and Rc is a hydrogen atom, an alkyl group The metal complex dye according to claim 11, which is a group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group or an amino group.
13. The metal complex dye according to claim 11, wherein in the formula (G-1), Ra and Rb are a hydrogen atom, an alkyl group, an alkylthio group or an amino group, and Rc is an aryl group.
14. In the formula (G-1), Ra and Rb are chain alkoxy groups or aryloxy groups, and Rc is a hydrogen atom, alkyl group, alkenyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group The metal complex dye according to claim 11, which is an alkylthio group, an arylthio group, or an amino group.
15. The metal complex dye according to any one of claims 11 to 14, wherein the metal complex dye represented by the formula (I) is represented by the following formula (II).
    

    

    In formula ^{(II), R A1 ~ R} A3 have the same meanings as ^R A1 ^{~ R A3} in the formula (AL-1). Z ² represents an isothiocyanate group, an isoselenocyanate group, an isocyanate group, a halogen atom or a cyano group. R ¹⁰ represents a hydrogen atom, an aryl group, a heterocyclic group or an alkyl group which may be substituted with a halogen atom. X and Ra to Rc have the same meanings as X and Ra to Rc in formula (G-1). na has the same meaning as na in formula (DL-1).

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