JP6300338B2 - Photoelectric conversion element, dye-sensitized solar cell, ruthenium complex dye and dye solution - Google Patents

Description

  The present invention relates to a photoelectric conversion element, a dye-sensitized solar cell, a ruthenium complex dye, and a dye solution.

  Photoelectric conversion elements are used in various photosensors, photocopiers, photoelectrochemical cells such as solar cells, and the like. Various methods such as a method using a metal, a method using a semiconductor, a method using an organic pigment or a dye, or a combination of these have been put to practical use for this photoelectric conversion element. In particular, a solar cell using non-depleting solar energy does not require fuel, and full-scale practical use is highly expected as it uses inexhaustible clean energy. Among them, silicon-based solar cells have been researched and developed for a long time, and are spreading due to the policy considerations of each country. However, since silicon is an inorganic material, there is a limit to improving throughput and cost.

Therefore, research on dye-sensitized solar cells has been vigorously conducted. In particular, it was the research results of Graetzel and others at the Swiss Lausanne University of Technology. They adopted a structure in which a dye composed of a ruthenium complex was fixed on the surface of a porous titanium oxide film, realizing photoelectric conversion efficiency comparable to that of amorphous silicon. As a result, dye-sensitized solar cells that can be manufactured without using an expensive vacuum apparatus have attracted attention from researchers all over the world.
To date, dyes called N3, N719, N749 (also referred to as black dye), Z907, and J2 have been developed as metal complex dyes used in dye-sensitized solar cells.

In addition to these dyes, metal complex dyes exhibiting improvements in photoelectric conversion efficiency of dye-sensitized solar cells have been developed.
For example, Patent Document 1 describes a terpyridine ligand, a specific pyridine-based bidentate ligand, and a metal complex dye in which a monodentate ligand is coordinated to a central metal, and this metal complex dye is photoelectrically converted. It is described that by using it as a sensitizing dye for an element, IPCE (Incident Photo to Current Convergency Efficiency) in a long wavelength region is increased and durability is also improved. In the dye described in Patent Document 1, the pyridine ring and the monodentate ligand of the bidentate ligand are in a cis configuration.

JP2013-72080A

  For practical use of dye-sensitized solar cells, high durability is required to stably maintain the photoelectric conversion performance when used in an external environment where they are installed (for example, an environment where the temperature changes greatly during the day and night). In order to realize such durability, it is important to stably maintain the state in which the sensitizing dye is supported on the surface of the semiconductor fine particles even in a severe field environment where the solar cell is installed. That is, if the sensitizing dye is easily detached from the surface of the semiconductor fine particles with respect to changes in the external environment, a practical battery that exhibits stable photoelectric conversion performance over a long period of time cannot be obtained.

The present invention relates to a photoelectric conversion element that exhibits high durability in which the photoelectric conversion efficiency is hardly lowered even by repeated temperature changes in the external environment (for example, severe temperature changes during the day and night), and dye sensitization using the photoelectric conversion element It is an object to provide a solar cell.
In addition, the present invention is a ruthenium complex dye suitable as a sensitizing dye for photoelectric conversion elements or dye-sensitized solar cells, having excellent adsorption stability to the surface of semiconductor fine particles, and temperature change in the external environment (for example, severe day and night) It is an object of the present invention to provide a ruthenium complex dye capable of producing a photoelectric conversion element or a dye-sensitized solar cell exhibiting high durability against repeated temperature changes. Moreover, this invention makes it a subject to provide the pigment | dye solution suitable for formation of the photoreceptor layer of the photoelectric conversion element thru | or dye-sensitized solar cell of this invention.

That is, the subject of this invention was 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 (1). A photoelectric conversion element having semiconductor fine particles carrying a ruthenium complex dye.

In the formula, M represents a hydrogen ion or a cation. X ¹ represents a nitrogen atom or CR ² . X ² represents a nitrogen atom when X ¹ is a nitrogen atom, and represents a nitrogen atom or CR ³ when X ¹ is CR ² . R ^{1 to} R ³ represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or a halogen atom. G ¹ represents a group represented by the following formula (G1).

In the formula, R ⁴ represents an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. m represents an integer of 1 to 3. n represents an integer of 0 to 2. Y ¹ represents an oxygen atom, a sulfur atom, NR ^f , a selenium atom, CR ^f ₂ or SiR ^f ₂ . R ^f represents a hydrogen atom or an alkyl group. * Represents a bond to the pyridine ring in formula (1).
<2> The photoelectric conversion element according to <1>, wherein X ¹ is CH and X ² is a nitrogen atom.
<3> The photoelectric conversion element according to <1> or <2>, wherein Y ¹ is a sulfur atom.
<4> The photoelectric conversion element according to any one of <1> to <3>, wherein n is 0.
<5> A dye-sensitized solar cell including the photoelectric conversion element according to any one of the above items <1> to <4>.
<6> A ruthenium complex dye represented by the following formula (1).

In the formula, M represents a hydrogen ion or a cation. X ¹ represents a nitrogen atom or CR ² . X ² represents a nitrogen atom when X ¹ is a nitrogen atom, and represents a nitrogen atom or CR ³ when X ¹ is CR ² . R ^{1 to} R ³ represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or a halogen atom. G ¹ represents a group represented by the following formula (G1).

In the formula, R ⁴ represents an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. m represents an integer of 1 to 3. n represents an integer of 0 to 2. Y ¹ represents an oxygen atom, a sulfur atom, NR ^f , a selenium atom, CR ^f ₂ or SiR ^f ₂ . R ^f represents a hydrogen atom or an alkyl group. * Represents a bond to the pyridine ring in formula (1).
<7> The ruthenium complex dye according to <6>, wherein X ¹ is CH and X ² is a nitrogen atom.
<8> The ruthenium complex dye according to <6> or <7>, wherein Y ¹ is a sulfur atom.
<9> The ruthenium complex dye according to any one of <6> to <8>, wherein n is 0.
<10> A dye solution obtained by dissolving the ruthenium complex dye according to any one of <6> to <9>.

In the present specification, unless otherwise specified, the double bond may be any of E type and Z type in the molecule, or a mixture thereof.
When there are a plurality of substituents, linking groups, ligands, etc. (hereinafter referred to as substituents, etc.) indicated by a specific symbol or formula, or when a plurality of substituents are specified simultaneously, unless otherwise specified The respective substituents may be the same as or different from each other. The same applies to the definition of the number of substituents and the like. Further, when a plurality of substituents and the like are close to each other (especially when they are adjacent to each other), they may be connected to each other to form a ring unless otherwise specified.

  Further, a ring, for example, an aromatic ring or an aliphatic ring may be further condensed to form a condensed ring.

  In this specification, about the display of a compound (a complex and a pigment | dye are included), it uses for the meaning containing its salt and its ion besides the compound itself. In addition, it means that a part of the structure is changed as long as the desired effect is achieved. Furthermore, a compound that does not clearly indicate substitution or non-substitution means that it may have an arbitrary substituent within a range that exhibits a desired effect. The same applies to substituents, linking groups and ligands.

  In addition, a numerical range expressed using “to” in this specification means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

The photoelectric conversion element and the dye-sensitized solar cell of the present invention exhibit high durability because the photoelectric conversion efficiency is hardly lowered even by repeated temperature changes of the external environment (for example, severe temperature changes day and night). In addition, the ruthenium complex dye of the present invention has excellent adsorption stability to the surface of the semiconductor fine particles, and enables production of photoelectric conversion elements or dye-sensitized solar cells that exhibit high durability against repeated temperature changes in the external environment. To do. In addition, the dye solution of the present invention can be suitably used for forming the photoelectric conversion element of the present invention or the photoreceptor layer of the dye-sensitized solar cell exhibiting the above high durability.
The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

FIG. 1 is a cross-sectional view schematically showing an enlarged view of a circular portion in a layer in a system in which the photoelectric conversion element according to the first aspect of the present invention is applied to a battery. FIG. 2 is a cross-sectional view schematically showing a dye-sensitized solar cell including the photoelectric conversion element according to the second aspect of the present invention.

[Photoelectric conversion element and dye-sensitized solar cell]
The photoelectric conversion element of the present invention has a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer body layer containing an electrolyte, and a counter electrode (counter electrode). The photosensitive layer, the charge transfer layer, and the counter electrode are provided on the conductive support in this order.

In the photoelectric conversion element of the present invention, at least a part of the semiconductor fine particles forming the photoreceptor layer carries a ruthenium complex dye represented by the following formula (1) as a sensitizing dye. Here, the aspect in which the ruthenium complex dye is supported on the surface of the semiconductor fine particle includes an aspect in which it is adsorbed on the surface of the semiconductor fine particle, an aspect in which the ruthenium complex dye is deposited on the surface of the semiconductor fine particle, and an aspect in which these are mixed. The adsorption includes chemical adsorption and physical adsorption, and chemical adsorption is preferable.
The semiconductor fine particles may carry another metal complex dye together with the ruthenium complex dye represented by the formula (1) described later, but as will be described later, the ruthenium complex dye represented by the formula (1). The isomer is substantially not supported.

  The photoreceptor layer contains an electrolyte. The electrolyte contained in the photoreceptor layer may be the same as or different from the electrolyte of the charge transfer layer, but is preferably the same.

  The photoelectric conversion element of the present invention is not particularly limited except for the structure defined in the present invention, and a known structure relating to the photoelectric conversion element can be adopted. Each of the layers constituting the photoelectric conversion element of the present invention is designed according to the purpose, and may be formed in a single layer or multiple layers, for example. Moreover, you may have layers other than said each layer if needed.

The dye-sensitized solar cell of the present invention uses the photoelectric conversion element of the present invention.
Hereinafter, preferred embodiments of the photoelectric conversion element and the dye-sensitized solar cell of the present invention will be described.

A system 100 shown in FIG. 1 is an application of the photoelectric conversion element 10 according to the first aspect of the present invention to a battery application in which an operation means M (for example, an electric motor) is caused to work by an external circuit 6.
The photoelectric conversion element 10 includes a conductive support 1, semiconductor fine particles 22 sensitized by supporting a dye (ruthenium complex dye) 21, and a photoreceptor layer 2 including an electrolyte between the semiconductor fine particles 22. It consists of a charge transfer layer 3 that is a hole transport layer and a counter electrode 4.
In the photoelectric conversion element 10, the light receiving electrode 5 includes the conductive support 1 and the photoreceptor layer 2, and functions as a working electrode.

  In the system 100 to which the photoelectric conversion element 10 is applied, light incident on the photoreceptor layer 2 excites the ruthenium complex dye 21. The excited ruthenium complex dye 21 has high-energy electrons, and the electrons are passed from the ruthenium 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 ruthenium complex dye 21 is an oxidant (cation). Electrons that have reached the conductive support 1 work in the external circuit 6, reach the oxidized form of the ruthenium complex dye 21 via the counter electrode 4 and the charge transfer layer 3, and reduce this oxidized form. The system 100 functions as a solar cell.

The dye-sensitized solar cell 20 shown in FIG. 2 is configured by the photoelectric conversion element of the second aspect of the present invention.
Although the photoelectric conversion element used as the dye-sensitized solar cell 20 differs with respect to the photoelectric conversion element shown in FIG. 1 by the structure of the electroconductive support body 41 and the photoreceptor layer 42, and the point which has a spacer, those points are the same. Other than that, the configuration is the same as that of the photoelectric conversion element 10 shown in FIG. That is, the conductive support 41 has a two-layer structure including a substrate 44 and a transparent conductive film 43 formed on the surface of the substrate 44. The photoreceptor layer 42 has a two-layer structure including a semiconductor layer 45 and a light scattering layer 46 formed adjacent to the semiconductor layer 45. A spacer is provided between the conductive support 41 and the counter electrode 48. In the dye-sensitized solar cell 20, reference numeral 40 denotes a light receiving electrode, and 47 denotes a charge transfer body layer.

  The dye-sensitized solar cell 20 functions as a solar cell when light enters the photoreceptor layer 42 as in the system 100 to which the photoelectric conversion element 10 is applied.

  The photoelectric conversion element and the dye-sensitized solar cell of the present invention are not limited to the above-described preferred embodiments, and the configurations and the like of each embodiment can be appropriately combined between the respective embodiments without departing from the gist of the present invention.

  In the present invention, materials and members used for the photoelectric conversion element or the dye-sensitized solar cell can be prepared by a conventional method. For example, US Pat. No. 4,927,721, US Pat. No. 4,684,537, US Pat. No. 5,084,365, US Pat. No. 5,350,644, U.S. Pat. No. 5,463,057, U.S. Pat. No. 5,525,440, JP-A-7-249790, JP-A 2001-185244, JP-A 2001-210390, JP Reference can be made to JP2003-217688A, JP2004220974A, and JP2008-135197A.

<Ruthenium complex dye>
-Ruthenium complex dye represented by formula (1)-
The ruthenium complex dye used in the present invention is represented by the following formula (1).

In the formula, M represents a hydrogen ion or a cation. X ¹ represents a nitrogen atom or CR ² . X ² represents a nitrogen atom when X ¹ is a nitrogen atom, and represents a nitrogen atom or CR ³ when X ¹ is CR ² . R ^{1 to} R ³ represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or a halogen atom. G ¹ represents a group represented by the following formula (G1).

(Representation method of configuration in ruthenium complex dye)
First, using the skeleton structure of the ruthenium complex dye represented by the formula (1), a description will be given of a method for representing the configuration of the chemical structural formula in the ruthenium complex dye.
In this specification, the three-dimensional structure of a ruthenium complex dye is shown using the following notation (I). The ruthenium complex dye represented by the following (I) includes a terpyridine ligand having three pyridine rings of ring A, a pyrazolylpyridine bidentate ligand in which a pyridine ring of ring B and a pyrazole ring of ring C are bonded to each other. , -NCS (isothiocyanate group) has a three-dimensional structure coordinated octagonally to Ru. Here, among the bonds to Ru, in the following notation (I), a bond indicated by a normal straight line indicates a bond on the paper surface (that is, the same plane), and a bond indicated by a wedge-shaped thick line is in front of the paper surface. This represents a bond, and a wedge-shaped broken line represents a bond on the other side (back side) of the page.
That is, the structure represented by the following (I) has a three-dimensional structure represented by the following (II) (that is, a transformer arrangement) when clearly expressed using a left-handed coordinate system of a three-dimensional orthogonal coordinate system. In this structure, with Ru as the origin, three pyridine rings of the ring A of the terpyridine ligand and a pyrazole ring of the ring C are arranged on the xy plane, and the pyridine ring of the ring B is located on the negative side of the z axis. This is a structure in which -NCS (isothiocyanate group) is arranged on the positive side of the z-axis.

(Trans and cis configuration)
In addition, in this specification, the trans configuration is defined in the octahedral hexacoordinated complex as described in “Basic Master Inorganic Chemistry” (2010, Ohm), page 240, edited by Hideki Masuda and Kunhei Nagashima. It means that the position of two ligands is on the opposite side across the metal ion. This trans configuration has a geometric isomer relationship with the cis configuration in which the positions of the two ligands are adjacent to each other. In this specification, the trans configuration-cis configuration expresses the positional relationship between the pyridine ring of L ^{2 in} the lower diagram and X in the lower diagram, and is a ruthenium complex dye represented by the formula (1) used in the present invention. The structure of is a transformer arrangement. A trans configuration and a cis configuration are schematically shown below.

In the above schematic diagram, L ¹ represents a terpyridine ligand composed of three pyridine rings, and each pyridine ring is represented by an N circled letter. L ² represents a bidentate ligand composed of a pyridine ring and a nitrogen-containing 5-membered ring, the pyridine ring is represented by a circled letter N, and the nitrogen-containing 5-membered ring is represented by G. X represents -NCS (isothiocyanate group). M ^I represents Ru.

The photoelectric conversion element of the present invention may use only the ruthenium complex dye represented by the formula (1) as the sensitizing dye, and is represented by the formula (1) together with the ruthenium complex dye represented by the formula (1). A metal complex dye different from the ruthenium complex dye may be used, but the isomer of the ruthenium complex dye represented by the formula (1) is not used. That is, in the present invention, “having the semiconductor fine particles carrying the ruthenium complex dye represented by the formula (1)” means that the ruthenium complex dye represented by the formula (1) is carried on the surface of the semiconductor fine particles, and It means a form in which the isomer of the ruthenium complex dye represented by the formula (1) is not supported on the surface of the semiconductor fine particles.
In the present specification, the “form in which the isomer of the ruthenium complex dye represented by the formula (1) is not supported on the surface of the semiconductor fine particles” is expressed by the formula (1) supported on the surface of the semiconductor fine particles. Ratio of the molar amount of the isomer of the ruthenium complex dye represented by the formula (1) in the total molar amount of the ruthenium complex dye and the isomer of the ruthenium complex dye represented by the formula (1) (hereinafter simply referred to as “isomer” Content ") is 0.5 mol% or less, preferably 0.3 mol% or less, more preferably 0.1 mol% or less. In addition, it is difficult to completely remove isomers in the synthesis of the ruthenium complex dye represented by the formula (1), and the practical lower limit of the above ratio is 0.01 mol% or more.
The isomers of the ruthenium complex dye represented by the formula (1) are isomers based on the complex structure of the ruthenium complex dye, and various isomers are exemplified. Examples thereof include stereoisomers and structural isomers.
Representative examples of stereoisomers include, for example, E isomers and Z isomers (E / Z isomers) in the double bond of a substituent, and geometric isomers based on the spatial arrangement (absolute configuration) of the ligand with respect to the central metal. Is mentioned.
On the other hand, representative examples of structural isomers include, for example, ionized isomers, coordination isomers, and bond isomers. The bond isomer refers to an isomer in which a ligand (bidentate ligand) capable of coordination with different atoms, for example, an -NCS group (isothiocyanate group) is coordinated with different atoms. For example, in the ruthenium complex dye represented by the formula (1) in which the —NCS group is coordinated with the nitrogen atom, the bond isomer includes a ruthenium complex dye in which the NCS group is coordinated with the sulfur atom.

  In the present invention, the “isomer of the ruthenium complex dye represented by the formula (1)” does not include an optical isomer based on a substituent having an asymmetric carbon atom, and is represented by the formula (1). When M of the ruthenium complex dye is a cation, isomers due to differences in the cation bonding position (the pyridine ring of the terpyridine ligand) are not included (that is, these isomers are included in the formula (1)). . Therefore, in the photoreceptor layer of the photoelectric conversion element of the present invention, these isomers may be supported on the semiconductor fine particles.

  The presence of the ruthenium complex dye represented by the formula (1) and its isomer is confirmed (identified) by peaks appearing at different positions (retention times) in high-performance liquid chromatography (HPLC). )it can. Therefore, the abundance ratio between the ruthenium complex dye represented by the formula (1) and the isomer of the ruthenium complex dye represented by the formula (1) can be determined by HPLC. Specifically, using a high performance liquid chromatography apparatus (Shimadzu Corporation), the measurement conditions are as follows: Column: YMC-Pac ODS-AM Model number AM-312, temperature 40 ° C., detection wavelength 254 nm, flow rate 1.0 mL / min, When the eluent is THF (tetrahydrofuran) / water / TFA (trifluoroacetic acid), it can be determined from the area ratio of each peak obtained.

  Hereinafter, the ruthenium complex dye used in the present invention will be described in more detail.

In the present invention, the ruthenium complex dye represented by the formula (1) is a 3-position of a pyridine ring in a bidentate ligand comprising a nitrogen-containing 5-membered ring and a pyridine ring (a nitrogen atom coordinated to ruthenium in the pyridine ring) And when the carbon atom bonded to the nitrogen-containing 5-membered ring is located at the 2-position, the 5-position) has a substituent G ¹ and the bidentate ligand is present in the trans position with respect to the NCS group By using this dye as a sensitizing dye, the durability of the photoelectric conversion element (particularly, durability against repeated severe temperature changes during the day and night) is greatly improved. The reason for this is estimated as follows. That is, when the ruthenium complex dye represented by the formula (1) is adsorbed on the surface of the semiconductor fine particles, the substituent G ¹ is located in the vicinity of the carboxy group in the terpyridine ligand. It is considered that the adsorption state is highly stabilized by the hydrophobic action of the substituent G ¹ .

  In the ruthenium complex dye represented by the formula (1), a cation that M can take is not particularly limited, and examples thereof include a positive counter ion (excluding a hydrogen ion) in the following counter ion CI. Of these, alkali metal ions or ammonium ions are preferred.

Preferred forms of the alkyl group, heteroaryl group, aryl group and halogen atom in R ^{1 to} R ³ are the same as the preferred forms of the corresponding groups in the substituent Z ^R described later.

The alkyl group that can be taken as R ^{1 to} R ³ is more preferably an alkyl group substituted with an electron withdrawing group, and further preferably an alkyl group substituted with a halogen atom, particularly a fluorine atom. In the alkyl group substituted with a halogen atom, the number of halogen atoms to be substituted is not particularly limited, and is preferably 1 or more, and preferably 1 to 6 or less, which is less than or equal to the number of hydrogen atoms of the alkyl group before being substituted. Is more preferable, and 1 to 3 is more preferable. Among them, the alkyl group substituted with a halogen atom is preferably a perhalogenated alkyl group in which all the hydrogen atoms of the alkyl group are substituted, more preferably a perfluoroalkyl group, and even more preferably trifluoromethyl.

The aryl group that can be taken by R ^{1 to} R ³ is more preferably an aryl group substituted with an electron withdrawing group, more preferably an aryl group substituted with a halogen atom, particularly a fluorine atom. In the aryl group substituted by a halogen atom, the number of halogen atoms to be substituted is not particularly limited, and is preferably 1 or more and preferably the number of hydrogen atoms of the aryl group before substitution is 2 to 5 Is more preferable, and 3 to 5 is more preferable. Among them, the aryl group substituted with a halogen atom is preferably a phenyl group substituted with a halogen atom. For example, 2,3,4,5-tetrafluorophenyl and 2,3,4,5,6-pentafluorophenyl are Can be mentioned.

The heteroaryl group that R ^{1 to} R ³ can take is preferably a heteroaryl group having any of a nitrogen atom, an oxygen atom, and a sulfur atom as a ring-constituting atom, and having 5 or 6 ring members. A heteroaryl group having any one of the atoms as a ring atom is more preferable, and the ring structure of the heteroaryl group is more preferably a thiazole ring, a pyridine ring or a thiophene ring, and a pyridine ring or a thiophene ring is particularly preferable. Incidentally, the heteroaryl group may have a substituent, examples of the substituent include the substituent Z ^R described later, the alkyl groups are preferred. Specific examples include 3-pyridinyl, 5-methyl-2-thiophenyl, and 2-thiazolyl.

R ¹ is preferably an alkyl group, a heteroaryl group, an aryl group or a halogen atom among the above groups, more preferably an alkyl group substituted with a fluorine atom, or an aryl group or heteroaryl group substituted with a fluorine atom. An alkyl group substituted with a fluorine atom is more preferred.

R ² is preferably a hydrogen atom or an alkyl group among the above groups, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.
R ³ is preferably a hydrogen atom.

X ¹ is preferably CR ² .
The combination of X ¹ and X ² (hereinafter described in the order of (X ¹ , X ² )) is preferably (nitrogen atom, nitrogen atom) or (CR ² , nitrogen atom), (nitrogen atom, nitrogen atom) or (CH, nitrogen atom) is more preferable, and (CH, nitrogen atom) is more preferable.

G ¹ is a group represented by the following formula (G1).

In the formula, R ⁴ represents an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group.
m represents an integer of 1 to 3. n represents an integer of 0 to 2.
Y ¹ represents an oxygen atom, a sulfur atom, NR ^f , a selenium atom, CR ^f ₂ or SiR ^f ₂ . Here, R ^f represents a hydrogen atom or an alkyl group. * Represents a bond to the pyridine ring in formula (1).

The preferable form of each group which can be taken as R ⁴ , R ⁵ and R ^f is the same as the preferable form of the corresponding group in the substituent Z ^R described later.

R ⁴ is preferably an alkyl group, an alkoxy group, an alkylthio group, an amino group, an aryl group, or a heteroaryl group, and more preferably an alkyl group, an alkoxy group, an alkylthio group, an amino group, or a heteroaryl group. An alkyl group, an alkoxy group or an alkylthio group is more preferable.
n is preferably 0 or 1, more preferably 1 when R ⁵ is a hydrogen atom, if R ⁵ is not hydrogen atom 0 are more preferred.
When n is 2, two R ⁴ may be bonded to each other to form a ring, or adjacent R ⁴ and R ⁵ may be bonded to form a ring. Examples of the ring formed include aryl rings such as a benzene ring, heteroaryl rings such as a pyrazine ring, pyrrole ring and thiophene ring, unsaturated hydrocarbon rings such as cyclopentadiene ring, 1,4-dioxane Examples include a ring, a hetero ring not showing an aromatic attribute such as a 2,3-dihydropyrazine ring, a ring formed by condensation of these rings (for example, a benzothiophene ring), and the like.

R ⁵ is preferably a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group or an amino group, and an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group or an alkylthio group among the above groups. More preferably, an alkyl group, an alkynyl group or an alkylthio group is more preferable, and an alkyl group is particularly preferable. The heteroaryl group that R ⁵ can take does not include the ring containing Y ¹ in the above formula (G1).

Y ¹ is preferably an oxygen atom, a sulfur atom or NR ^f, more preferably an oxygen atom or a sulfur atom, and further preferably a sulfur atom.
m is preferably 1 or 2, and more preferably 1.
when m is 2 or 3, among R ⁴ having the ring containing the adjacent Y ^1, R ⁴ is bonded to the ring containing the other Y ¹ to form a ring having the ring containing one Y ¹ Alternatively, R ^{4 s in} two adjacent rings including Y ¹ may be bonded to form a ring. The ring formed is synonymous with the ring formed by R ⁴ described above.

  The group represented by the formula (G1) is preferably a group represented by any of the following formulas (G1-1a) to (G1-7a), and is represented by the formula (G1-1a) or the formula (G1-5a). The group represented by Formula (G1-1a) is more preferable.

In formula ^{(G1-1a) ~ (G1-7a),} R 5, Y 1 and m are each equation in ^(G1), has the same meaning as R 5, ^{Y 1} and m, the preferred range is also the same.
R ⁶ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group.
R ⁷ represents a hydrogen atom or a substituent (preferably an alkyl group, alkynyl group, alkenyl group, alkoxy group, alkylthio group, amino group, heteroaryl group or aryl group).
An alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group and an aryl group that can be taken as R ⁶ and R ⁷ are an alkyl group and an alkynyl group that can be taken as R ^{4 in the} formula (G1), respectively. , An alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group and an aryl group, and the preferred range is also the same. R ⁶ and R ⁷ are preferably a hydrogen atom, alkyl group, alkoxy group, alkylthio group, amino group, aryl group or heteroaryl group, and a hydrogen atom, alkyl group, alkoxy group, alkylthio group, amino group or heteroaryl group is preferred. More preferably, a hydrogen atom, an alkyl group, an alkoxy group or an alkylthio group is more preferable, and a hydrogen atom is particularly preferable.

Z ¹ represents a nitrogen atom or CR ^a, and is preferably a nitrogen atom.
Z ^{2 to} Z ^{5 each} represents an oxygen atom, a sulfur atom, NR ^b , CR ^b ₂ , a selenium atom, or SiR ^b ₂ . Z ² is preferably NR ^b or CR ^b ₂ , and Z ^{3 to} Z ⁵ are preferably oxygen atoms or sulfur atoms. Z ³ is more preferably an oxygen atom.
R ^a and R ^b represent a hydrogen atom or an alkyl group. The preferable form of the alkyl group which can be taken as R ^a and R ^b is the same as the preferable form of the alkyl group in the substituent Z ^R described later.

  In the present specification, the ruthenium complex dye represented by the formula (1) includes a form containing a counter ion (CI) for neutralizing the charge of the ruthenium complex dye.

  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), phosphonium ion (for example, tetraalkylphosphonium ion, alkyltriphenylphosphonium ion). , Alkali metal ions (Li ion, Na ion, K ion, etc.), alkaline earth metal ions, metal complex ions, or hydrogen ions. The positive counter ion is preferably an inorganic or organic ammonium ion (tetraethylammonium ion, tetrabutylammonium ion, etc.) or a hydrogen ion.

  When the counter ion CI is a negative counter ion, the counter ion CI may be an inorganic anion or an organic anion. For example, hydroxide ion, halogen anion (eg fluoride ion, chloride ion, bromide ion, iodide ion), substituted or unsubstituted alkylcarboxylate ion (acetate ion, trifluoroacetate ion, etc.), substituted Alternatively, an unsubstituted aryl carboxylate ion (benzoate ion, etc.), a substituted or unsubstituted alkyl sulfonate ion (methane sulfonate ion, trifluoromethane sulfonate ion, etc.), a substituted or unsubstituted aryl sulfonate ion (eg, p -Toluenesulfonic acid ion, p-chlorobenzenesulfonic acid ion), aryl disulfonic acid ion (for example, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion), alkyl sulfuric acid Ion (for example Methylsulfate ion), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, and a picrate ion. Further, as the charge balance counter ion, an ionic polymer or another dye having a charge opposite to that of the dye may be used, and a metal complex ion (for example, bisbenzene-1,2-dithiolatonickel (III)) can also be used. . Negative counter ions include halogen anions, substituted or unsubstituted alkyl carboxylate ions, substituted or unsubstituted alkyl sulfonate ions, substituted or unsubstituted aryl sulfonate ions, aryl disulfonate ions, perchlorate ions Or a hexafluorophosphate ion is preferable and a halogen anion or a hexafluorophosphate ion is more preferable.

  Examples of the ruthenium complex dye represented by the above formula (1) include a method described in JP2013-084594A, a method described in Japanese Patent No. 4298799, US Patent Application Publication No. 2013 / 0018189A1, and US Patent Application. Methods described in published 2012 / 0073660A1, published US 2012 / 0111410A1 and published published US 2010 / 0258175A1, Angew. Chem. Int. Ed. , 2011, 50, 2054-2058, Chem. Commun. , 2014, 50, 6379-6381, the method described in Chemical Communications, 2009, 5844-5846, the method described in Journal of Materials Chemistry A, 2014, 2, 17618-17627, and these literatures. An intermediate in which a terpyridine ligand and a bidentate ligand are coordinated to Ru with reference to the method described in the reference literature, the above-mentioned patent document on solar cells, a known method, or a method analogous thereto By changing the heating temperature or solvent during the synthesis, a mixture containing a large amount of the ruthenium complex dye represented by the formula (1), which is a trans geometric isomer, is obtained, and the trans geometric isomer is converted from the intermediate mixture into a silica gel column. Prepare by isolation by chromatography, etc. can do. The operation of isolating the trans geometric isomer can be carried out at any stage from the above intermediate to the ruthenium complex dye.

  In the ruthenium complex dye represented by the formula (1), the maximum absorption wavelength in the solution is preferably in the range of 300 to 900 nm, more preferably in the range of 350 to 850 nm, and particularly preferably in the range of 370 to 800 nm. is there. Moreover, it is preferable that the absorption wavelength region covers the entire 300 to 900 nm.

  In the following description (including examples), specific examples of the ruthenium complex dye represented by the formula (1) are shown. In addition to the following specific examples and specific examples, metal complex dyes in which at least one of -COOH is a salt of a carboxy group are also included. In this metal complex dye, examples of the counter cation that forms a salt of a carboxy group include positive ions described in the above CI. The present invention is not limited to these. When the ruthenium complex dye of the following specific example includes a ligand having a proton dissociable group, the ligand may be dissociated as necessary to release a proton.

<Substituent group Z ^R >
The substituent in the present invention, substituents selected from Substituent Group Z ^R.
In the present specification, when simply not listed only as substituents, it is intended to refer to the substituent group Z ^R. Further, each of the groups (for example, an alkyl group, an aryl group, etc.) in the case of only are described, preferably in the corresponding group in the substituent group Z ^R (for example, an alkyl group in Z ^R, an aryl group, etc.) Ranges, specific examples apply.

The group contained in the substituent group Z ^R, including the following groups or, by combining a plurality of groups of the following groups.
Alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms such as methyl, ethyl, isopropyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 1-ethylpentyl, 2-ethylhexyl) Benzyl, 2-ethoxyethyl or trifluoromethyl), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12, for example, vinyl, allyl, butenyl or oleyl), an alkynyl group (preferably having a carbon number) 2 to 20, more preferably 2 to 12, for example, ethynyl, butynyl, octynyl or phenylethynyl), a cycloalkyl group (preferably having 3 to 20 carbon atoms), a cycloalkenyl group (preferably having 5 to 20 carbon atoms), An aryl group (preferably having from 6 to 26 carbon atoms such as phenyl, 1-naphth , 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, difluorophenyl or tetrafluorophenyl), a heterocyclic group (preferably having 2 to 20 carbon atoms and having at least one oxygen atom, sulfur atom or nitrogen atom) A 5-membered or 6-membered heterocyclic group is more preferable, which includes an aromatic ring and an aliphatic ring, and examples of the aromatic heterocyclic group (for example, heteroaryl group) include the following groups. 2-pyridyl, 2-thienyl, 2-furanyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2-thiazolyl or 2-oxazolyl), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms). For example, methoxy, ethoxy, isopropyloxy, hexyloxy, octyloxy or benzene Ruoxy), an alkenyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12), an alkynyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12), a cycloalkyloxy group (preferably 3 to 20 carbon atoms), an aryloxy group (preferably 6 to 26 carbon atoms), a heterocyclic oxy group (preferably 2 to 20 carbon atoms),

An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms), a cycloalkoxycarbonyl group (preferably having 4 to 20 carbon atoms), an aryloxycarbonyl group (preferably having 6 to 20 carbon atoms), an amino group (preferably having 0 to 0 carbon atoms). 20 includes an alkylamino group, an alkenylamino group, an alkynylamino group, a cycloalkylamino group, a cycloalkenylamino group, an arylamino group, a heterocyclic amino group, such as amino, N, N-dimethylamino, N, N -Diethylamino, N-ethylamino, N-allylamino, N- (2-propynyl) amino, N-cyclohexylamino, N-cyclohexenylamino, N, N-diphenylamino, anilino, pyridylamino, imidazolylamino, benzimidazolylamino, thiazolylamino , Benzothiazo Ruamino or triazinylamino), a sulfamoyl group (preferably an alkyl, cycloalkyl or aryl sulfamoyl group having 0 to 20 carbon atoms), an acyl group (preferably 1 to 20 carbon atoms), an acyloxy group (preferably Carbon number 1-20), a carbamoyl group (preferably an carbamoyl group having 1-20 carbon atoms, alkyl, cycloalkyl or aryl),

An acylamino group (preferably having 1 to 20 carbon atoms), a sulfonamide group (preferably an alkyl, cycloalkyl or aryl sulfonamide group having 0 to 20 carbon atoms), an alkylthio group (preferably having 1 to 20 carbon atoms, More preferably, it is 1-12, for example, methylthio, ethylthio, isopropylthio, pentylthio, hexylthio, octylthio or benzylthio), cycloalkylthio group (preferably having 3 to 20 carbon atoms), arylthio group (preferably having 6 to 26 carbon atoms) An alkyl, cycloalkyl or arylsulfonyl group (preferably having 1 to 20 carbon atoms),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted by alkyl, aryl, alkoxy and aryloxy), a silyloxy group (preferably having 1 to 20 carbon atoms, alkyl, aryl, alkoxy and aryloxy are A substituted silyloxy group is preferred), a hydroxy group, a cyano group, a nitro group, and a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom or an iodine atom).

Group selected from substituent group Z ^R is more preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an alkoxy group, cycloalkoxy group, aryloxy group, alkoxycarbonyl group, cycloalkoxy carbonyl group Amino group, acylamino group, cyano group or halogen atom, particularly preferably alkyl group, alkenyl group, heterocyclic group, alkoxy group, alkoxycarbonyl group, amino group, acylamino group or cyano group.

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

  Next, the preferable aspect of the main member of a photoelectric conversion element and a dye-sensitized solar cell is demonstrated.

<Conductive support>
The conductive support is not particularly limited as long as it has conductivity and can support the photoreceptor layer 2 and the like. The conductive support includes the conductive support 1 made of a conductive material, for example, a metal, or a glass or plastic substrate 44 and a transparent conductive film 43 formed on the surface of the substrate 44. A conductive support 41 is preferred.

Especially, the electroconductive support body 41 which has the transparent conductive film 43 of a metal oxide on the surface of the board | substrate 44 is preferable. Such a conductive support 41 is obtained by applying a conductive metal oxide to the surface of the substrate 44 to form a transparent conductive film 43. Examples of the substrate 44 made of plastic include a transparent polymer film described in paragraph No. 0153 of JP-A-2001-291534. In addition to glass and plastic, the material for forming the substrate 44 may be ceramic (Japanese Patent Laid-Open No. 2005-135902) or conductive resin (Japanese Patent Laid-Open No. 2001-160425). As the metal oxide, tin oxide (TO) is preferable, and fluorine-doped tin oxide such as indium-tin oxide (tin-doped indium oxide; ITO) and fluorine-doped tin oxide (FTO) is particularly preferable. The coating amount of the metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of the surface area of the substrate 44. When the conductive support 41 is used, light is preferably incident from the substrate 44 side.

Conductive supports 1 and 41 are preferably substantially transparent. “Substantially transparent” means that the transmittance of light (wavelength 300 to 1200 nm) is 10% or more, preferably 50% or more, and particularly preferably 80% or more. .
The thickness of the conductive supports 1 and 41 is not particularly limited, but is preferably 0.05 μm to 10 mm, more preferably 0.1 μm to 5 mm, and particularly preferably 0.3 μm to 4 mm. .
When the transparent conductive film 43 is provided, the thickness of the transparent conductive film 43 is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm. .

  The conductive supports 1 and 41 may have a light management function on the surface. 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 may be provided on the surface, as described in JP-A-2002-260746. The light guide function may be provided.

<Photoreceptor layer>
Other configurations are not particularly limited as long as the photoreceptor layer includes the semiconductor fine particles 22 on which the dye 21 is supported and an electrolyte. Preferably, the photoreceptor layer 2 and the photoreceptor layer 42 are used.

− Semiconductor fine particles (layers formed by semiconductor fine particles) −
The semiconductor fine particles 22 are preferably fine particles of a metal chalcogenide (for example, oxide, sulfide, selenide) or a compound having a perovskite crystal structure. Preferred examples of the metal chalcogenide include titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum oxide, cadmium sulfide, and cadmium selenide. Preferred examples of the compound having a perovskite crystal structure include strontium titanate and calcium titanate. Of these, titanium oxide (titania), zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

  The crystal structure of titania includes anatase type, brookite type, or rutile type, and anatase type and brookite type are preferable. Titania nanotubes, nanowires, and nanorods can be used alone or mixed with titania fine particles.

  The particle size of the semiconductor fine particles 22 is 0.001 to 1 μm as the primary particle in terms of the average particle size when the projected area is converted into a circle, and 0.01 to 100 μm as the average particle size of the dispersion. Is preferred. Examples of a method for coating the semiconductor fine particles 22 on the conductive support 1 or 41 include a wet method, a dry method, and other methods.

  The semiconductor fine particles 22 preferably have a large surface area so that a large amount of the dye 21 can be adsorbed. For example, in a state where the semiconductor fine particles 22 are coated on the conductive support 1 or 41, the surface area thereof 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.

  The preferred thickness of the layer formed by the semiconductor fine particles is not uniquely defined depending on the use of the photoelectric conversion element, but is typically 0.1 to 100 μm. When using as a dye-sensitized solar cell, 1-50 micrometers is more preferable and 3-30 micrometers is more preferable.

  The semiconductor fine particles 22 are preferably applied to the conductive support 1 or 41 and then baked at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours to bring the particles into close contact with each other. The film forming temperature is preferably 60 to 600 ° C. when glass is used as the material of the conductive support 1 or the substrate 44.

The coating amount of the semiconductor fine particles 22 per 1 m ² of the surface area of the conductive support 1 or 41 is preferably 0.5 to 500 g, more preferably 5 to 100 g.

Between the conductive support 1 or 41 and the photoreceptor layer 2 or 42, in order to prevent reverse current due to direct contact between the electrolyte contained in the photoreceptor layer 2 or 42 and the conductive support 1 or 41. It is preferable to form a short-circuit prevention layer.
In order to prevent contact between the light receiving electrode 5 or 40 and the counter electrode 4 or 48, it is preferable to use a spacer S (see FIG. 2) or a separator.

− Dye −
In the photoelectric conversion element 10 and the dye-sensitized solar cell 20, at least one ruthenium complex dye represented by the above formula (1) is used as the sensitizing dye.

  In the present invention, as a dye that can be used in combination with the ruthenium complex dye represented by the formula (1), a Ru complex dye other than the ruthenium complex dye represented by the formula (1) (however, the ruthenium represented by the formula (1)) Isomers in complex dyes are as described above), squarylium cyanine dyes, organic dyes, porphyrin dyes, phthalocyanine dyes, and the like.

  The dye that can be used in combination is preferably a Ru complex dye other than the ruthenium complex dye represented by the formula (1), a squarylium cyanine dye, or an organic dye.

The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, particularly preferably 0.1 to 10 mmol per 1 m ² of the surface area of the conductive support 1 or 41. is there. Further, the adsorption amount of the dye 21 to the semiconductor fine particles 22 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 22. By using such a dye amount, the sensitizing effect in the semiconductor fine particles 22 can be sufficiently obtained.

  When the ruthenium complex dye represented by the formula (1) and another dye are used in combination, the ratio of the mass of the ruthenium complex dye represented by the formula (1) / the mass of the other dye is 95/5 to 10/90. Is preferable, 95/5 to 50/50 is more preferable, 95/5 to 60/40 is more preferable, 95/5 to 65/35 is particularly preferable, and 95/5 to 70/30 is most preferable.

  After the dye is supported on the semiconductor fine particles 22, the surface of the semiconductor fine particles 22 may be treated with an amine compound. Preferable amine compounds include pyridine compounds (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.

− Coadsorbent −
In the present invention, it is preferable to further use a coadsorbent together with the ruthenium complex dye represented by the formula (1) or the dye used in combination as 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 a compound having a fatty acid or a steroid skeleton.
The fatty acid may be a saturated fatty acid or an unsaturated fatty acid, and examples thereof include butanoic acid, hexanoic acid, octanoic acid, decanoic acid, hexadecanoic acid, dodecanoic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid.
Examples of the compound having a steroid skeleton include cholic acid, glycocholic acid, chenodeoxycholic acid, hyocholic acid, deoxycholic acid, lithocholic acid, ursodeoxycholic acid and the like. Preferred are cholic acid, deoxycholic acid, and chenodeoxycholic acid, and more preferred is deoxycholic acid.
The co-adsorbent is preferably a co-adsorbent represented by the formula (CA) described in paragraph Nos. 0125 to 0129 of JP2014-82187A, and the number of paragraphs 0125 to 0129 of JP2014-82187A is preferable. The description is preferably incorporated herein as it is.

  The co-adsorbent has an effect of suppressing inefficient association of the ruthenium complex dye and an effect of preventing reverse electron transfer from the surface of the semiconductor fine particles to the redox system in the electrolyte by being adsorbed on the semiconductor fine particles 22. Although the usage-amount of a coadsorbent is not specifically limited, From a viewpoint of expressing said effect | action effectively, Preferably it is 1-200 mol with respect to 1 mol of said ruthenium complex pigment | dyes, More preferably, it is 10-150 mol, Most preferably, it is 20-50 mol.

− Light scattering layer −
In the present invention, the light scattering layer is different from the semiconductor layer in that it has a function of scattering incident light.
In the dye-sensitized solar cell 20, the light scattering layer 46 preferably contains rod-like or plate-like metal oxide fine particles. Examples of the metal oxide used in the light scattering layer 46 include the chalcogenide (oxide) of the metal described as the compound that forms the semiconductor fine particles. When the light scattering layer 46 is provided, the thickness of the light scattering layer is preferably 10 to 50% of the thickness of the photoreceptor layer 42.
The light scattering layer 46 is preferably a light scattering layer described in JP-A-2002-289274, and the description of JP-A-2002-289274 is preferably incorporated in the present specification as it is.

<Charge transfer layer>
The charge transfer layer 3 and 47 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 21, and between the light receiving electrode 5 or 40 and the counter electrode 4 or 48. Provided.
The charge transfer layer 3 and 47 contains an electrolyte. Here, “the charge transfer layer contains an electrolyte” means to include both modes of the mode in which the charge transfer layer is made of only an electrolyte and the mode containing an electrolyte and a substance other than the electrolyte.
The charge transfer body layers 3 and 47 may be solid, liquid, gel, or a mixed state thereof.

− Electrolyte −
Examples of the electrolyte include a liquid electrolyte in which a redox pair is dissolved in an organic solvent, a so-called gel electrolyte in which a polymer matrix is impregnated with a molten salt containing a redox pair and a liquid in which a redox pair is dissolved in an organic solvent. Especially, a liquid electrolyte is preferable at the point of photoelectric conversion efficiency.

  As an oxidation-reduction pair, for example, iodine and iodide (iodide salt, ionic liquid is preferable, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, methylpropylimidazolium iodide are preferable) Combinations, combinations of alkyl viologens (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and reduced forms thereof, combinations of polyhydroxybenzene (for example, hydroquinone, naphthohydroquinone) and oxidized forms thereof, bivalent and 3 A combination of a valent iron complex (for example, a combination of red blood salt and yellow blood salt), and a combination of a divalent and trivalent cobalt complex. Among these, a combination of iodine and iodide or a combination of divalent and trivalent cobalt complexes is preferable, and a combination of iodine and iodide is particularly preferable.

  The cobalt complex is preferably a complex represented by the formula (CC) described in paragraphs 0144 to 0156 of JP2014-82189A, and the description of paragraphs 0144 to 0156 of JP2014-82189A is described below. It is preferably incorporated in the present specification as it is.

  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 used for the liquid electrolyte and the gel electrolyte is not particularly limited, but an aprotic polar solvent (for example, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3 -Methyloxazolidinone) is preferred.
In particular, the organic solvent used for the liquid electrolyte is preferably a nitrile compound, an ether compound, an ester compound, more preferably a nitrile compound, and particularly preferably acetonitrile or methoxypropionitrile.

  As the molten salt or gel electrolyte, those described in paragraph numbers 0205 and 0208-0213 of JP-A No. 2014-139931 are preferable, and those of paragraph numbers 0205 and 0208-0213 of JP-A No. 2014-139931 are preferable. The description is preferably incorporated herein as it is.

  In addition to pyridine compounds such as 4-t-butylpyridine, electrolytes include aminopyridine compounds, benzimidazole compounds, aminotriazole compounds and aminothiazole compounds, imidazole compounds, aminotriazine compounds, urea compounds, amide compounds, and pyrimidines as additives. It may contain a compound or a nitrogen-free heterocycle.

Moreover, in order to improve photoelectric conversion efficiency, you may take the method of controlling the water | moisture content of electrolyte solution. Preferred methods for controlling moisture include a method for controlling the concentration and a method in which a dehydrating agent is allowed to coexist. It is preferable to adjust the water content (content) of the electrolytic solution to 0 to 0.1% by mass.
Iodine can also be used as an inclusion compound of iodine and cyclodextrin. Cyclic amidine may be used, and an antioxidant, hydrolysis inhibitor, decomposition inhibitor, and zinc iodide may be added.

  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 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. As the organic hole transport material, those described in paragraph No. 0214 of JP-A-2014-139931 are preferable.

  Since the redox couple becomes an electron carrier, it is preferably contained at a certain concentration. 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.

<Counter electrode>
The counter electrodes 4 and 48 preferably function as positive electrodes of the dye-sensitized solar cell. The counter electrodes 4 and 48 can usually have the same configuration as that of the conductive support 1 or 41, but the substrate 44 is not necessarily required in a configuration in which the strength is sufficiently maintained. As the structure of the counter electrodes 4 and 48, a structure having a high current collecting effect is preferable. In order for light to reach the photoreceptor layers 2 and 42, at least one of the conductive support 1 or 41 and the counter electrode 4 or 48 must be substantially transparent. In the dye-sensitized solar cell of the present invention, the conductive support 1 or 41 is preferably transparent, and sunlight is preferably incident from the conductive support 1 or 41 side. In this case, it is more preferable that the counter electrodes 4 and 48 have a property of reflecting light. As the counter electrodes 4 and 48 of the dye-sensitized solar cell, a glass or plastic on which a metal or conductive oxide is vapor-deposited is preferable, and a 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.

[Method for producing photoelectric conversion element and dye-sensitized solar cell]
The photoelectric conversion element and the dye-sensitized solar cell of the present invention can be produced using the dye solution (the dye solution of the present invention) containing the ruthenium complex dye of the present invention and a solvent.

  In such a dye solution, the ruthenium complex dye of the present invention is dissolved in a solvent, and may contain other components such as the co-adsorbent as necessary.

  Examples of the solvent to be used include the solvents described in JP-A No. 2001-291534, but are not particularly limited thereto. In the present invention, an organic solvent is preferable, and an alcohol solvent, an amide solvent, a nitrile solvent, a hydrocarbon solvent, and a mixed solvent of two or more of these are more preferable. As the mixed solvent, a mixed solvent of an alcohol solvent and a solvent selected from an amide solvent, a nitrile solvent, or a hydrocarbon solvent is preferable. More preferred are a mixed solvent of an alcohol solvent and an amide solvent, a mixed solvent of an alcohol solvent and a hydrocarbon solvent, and particularly preferred is a mixed solvent of an alcohol solvent and an amide solvent. Specifically, a mixed solvent of at least one of methanol, ethanol, propanol and butanol and at least one of dimethylformamide, dimethylacetamide and acetonitrile is preferable.

The dye solution preferably contains a co-adsorbent, and the co-adsorbent is preferably the above-mentioned co-adsorbent.
Here, the dye solution of the present invention is a dye solution in which the concentration of a ruthenium complex dye or a co-adsorbent is adjusted so that the solution can be used as it is when producing a photoelectric conversion element or a dye-sensitized solar cell. Is preferred. In the present invention, the dye solution of the present invention preferably contains 0.001 to 0.1% by mass of the ruthenium complex dye of the present invention. The amount of coadsorbent used is as described above.

  The pigment solution preferably adjusts the water content. In the present invention, the water content is preferably adjusted to 0 to 0.1% by mass.

In the present invention, it is preferable to prepare a photoreceptor layer by supporting the ruthenium complex dye represented by the formula (1) or a dye containing the same on the surface of the semiconductor fine particles using the dye solution. That is, the photoreceptor layer is preferably formed by applying the above dye solution (including a dip method) to semiconductor fine particles provided on a conductive support, and drying or curing.
The photoelectric conversion element of the present invention can be obtained by further providing a charge transfer layer, a counter electrode, and the like on the light-receiving electrode provided with the photoreceptor layer thus prepared.

  The dye-sensitized solar cell is manufactured by connecting the external circuit 6 to the conductive support 1 and the counter electrode 4 of the photoelectric conversion element manufactured as described above.

  By forming the photoreceptor layer of the photoelectric conversion element using the dye solution of the present invention, the adsorption stability of the dye to the semiconductor surface can be highly enhanced, and the temperature change of the obtained photoelectric conversion element The reduction rate of the current value with respect to the repetition of the above can be effectively suppressed, and a photoelectric conversion element and a dye-sensitized solar cell exhibiting stable battery performance can be manufactured.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1
[Preparation of ruthenium complex dye]
The structures of the ruthenium complex dyes Dye-2, 3 and 5-12 of the present invention and the ruthenium complex dyes Dye-1 and 4 of the comparative examples are shown below.

(Preparation of ruthenium complex dye Dye-1)
The ruthenium complex dye Dye-1 is prepared by reacting Ru4 with a terpyridine ligand according to the synthesis method of PRT4 described in the specification of US Patent Application Publication No. 2012 / 0111410A1, and then, by using silica gel column chromatography, The intermediate which becomes a precursor was isolated, and the subsequent operations were synthesized in the same manner as the synthesis method of PRT4. From mass spectrometry and ¹ H NMR, it was confirmed that Dye-1 is a geometric isomer of PRT4 described in the specification of US Patent Application Publication No. 2012 / 0111410A1.

(Preparation of ruthenium complex dyes Dye-2 and 4)
Ruthenium complex dyes Dye-2 and 4 are reacted with a ruthenium bidentate ligand complex and a terpyridine ligand according to the synthesis method of PRT1 described in Chemical Communications, 2009, 5844-5846 and Supplementary Materials of this document. Then, intermediates to be precursors of Dye-2 and Dye-4 were isolated by silica gel column chromatography, and the subsequent operations were respectively performed in the same manner as the synthesis method of PRT1. From mass spectrometry and ¹ H NMR, it was confirmed that Dye-2 and Dye-4 were geometric isomers.

(Preparation of ruthenium complex dye Dye-3)
Ruthenium complex dye Dye-3 was synthesized according to the following scheme. The meanings of the abbreviations in the following scheme and specification are as follows.
Ph: Phenyl Et: Ethyl

That is, the intermediate 3-1 was reacted with the Ru-terpyridine complex with reference to the synthesis method of PRT-21 described in Journal of Materials Chemistry A, 2014, 2, 17618-17627, and Electronic supplementary information of this document. Later, intermediate 3-2 was isolated by silica gel column chromatography, and the subsequent operations were synthesized in the same manner as the synthesis method of PRT-21. From mass spectrometry and ¹ H NMR, it was confirmed that Dye-3 was a geometric isomer of Dye3 described in JP2013-72080A.

Intermediate 3-2
¹ H NMR (CDCl ₃ ): δ = 0.90 (t, J = 6 Hz, 3H), 1.42 (t, J = 8 Hz, 9H), 1.30-1.80 (m, 8H), 2 .88 (t, J = 6 Hz, 2H), 4.46 (q, J = 8 Hz, 4H), 4.63 (q, J = 8 Hz, 2H), 6.60 (s, 1H), 6.99 (D, J = 3.6 Hz, 1H), 7.52 (d, J = 3.6 Hz, 1H), 7.75 (dd, J = 2, 5.6 Hz, 2H), 7.82 (d, J = 8.4 Hz, 1H), 8.00 (d, J = 5.6 Hz, 2H), 8.18 (dd, J = 2, 8.4 Hz, 1H), 8.77 (s, 2H), 8.92 (s, 2H), 10.31 (d, J = 1.6 Hz, 1H)
ESI-MS m / z = 965.2 (M + H ⁺ )

Comparison (geometric isomer of intermediate 3-2 (Dye3 intermediate described in JP2013-72080A))
¹ H NMR (CDCl ₃ ): δ = 0.90 (t, J = 6 Hz, 3H), 1.42 (t, J = 8 Hz, 9H), 1.30-1.80 (m, 8H), 2 .88 (t, J = 6 Hz, 2H), 4.46 (q, J = 8 Hz, 4H), 4.63 (q, J = 8 Hz, 2H), 6.71 (s, 1H), 6.85 (D, J = 3.6 Hz, 1H), 7.45 (d, J = 3.6 Hz, 1H), 7.75 (dd, J = 2, 5.6 Hz, 2H), 7.81 (d, J = 8.4 Hz, 1H), 8.00 (d, J = 5.6 Hz, 2H), 8.09 (dd, J = 2, 8.4 Hz, 1H), 8.72 (s, 2H), 8.84 (s, 2H), 10.31 (d, J = 1.6 Hz, 1H)
ESI-MS m / z = 965.2 (M + H ⁺ )

(Preparation of ruthenium complex dye Dye-5-12)
Ruthenium complex dyes Dye-5 to 12 were prepared in the same manner as the preparation of ruthenium complex dyes Dye-2 or Dye-3.

  Each of the prepared ruthenium complex dyes was identified by MS (mass spectrum) measurement. The results are summarized in Table 1 below. In addition, all of the prepared dyes had an isomer content of 0.1 mol% or less.

Example 2
[Adsorption stability of ruthenium complex dyes]
The adsorption stability (adsorption power) of ruthenium complex dyes on the surface of semiconductor fine particles was evaluated. In this evaluation of adsorptivity, titanium dioxide was used as the semiconductor fine particles, and the desorption rate of the ruthenium complex dye from the titanium dioxide surface was used as an index.
The desorption rate of the ruthenium complex dye was calculated using a Quartz Crystal microbalance with Dissipation monitoring (QCM-D) intermolecular interaction measuring apparatus E1 (manufactured by Meiwa Forsys, Inc.).
A titania paste “18NR-T” (manufactured by DyeSol) was printed by screen printing on a gold sensor (manufactured by Meiwa Forsys, Inc.) used for QCM-D (film thickness: 20 μm). The gold sensor with the semiconductor layer adsorbed was produced by baking the gold sensor after printing at 450 ° C. for 1 hour in the air.
The prepared sensor is set in the QCM-D intermolecular interaction measurement device, and a 0.2 mM ruthenium complex dye solution (the solvent is a mixed solvent having a volume ratio of 1: 1 between DMF (dimethylformamide) and t-butanol). The dye was adsorbed to the semiconductor layer so that the dye adsorption amount became a predetermined value (200 μg / cm ² ). The dye adsorption amount was calculated from the resonance frequency shift (ΔF) of the crystal resonator by the following Sauerbrey equation.

ΔF = −2 × F ₀ ² × Δm / A (μ × P) ^1/2

Here, F ₀ is the single frequency of the crystal resonator, Δm is the mass change, A is the piezoelectric active area of the Au electrode, and μ and P are the density and rigidity of the crystal, respectively.

Thereafter, iodine 0.1M (mol / L), lithium iodide 0.1M, 4-t-butylpyridine 0.5M and 1,2-dimethyl-3-propylimidazolium iodide 0.6M were dissolved in acetonitrile. The amount of the detached dye was measured by flowing the prepared electrolyte solution at 75 ° C. for 1 hour. The amount of dye desorbed was calculated by the above Sauerbrey equation, and the adsorption stability was evaluated according to the following evaluation criteria based on the amount of dye desorbed per hour, that is, the desorption rate μg / cm ² · hr.

− Evaluation criteria −
A: desorption rate is 10μg / ^cm 2 · hr less B: desorption rate is 10μg / ^cm 2 · hr or more ~20μg / ^cm 2 · hr than C: desorption rate is 20μg / ^cm 2 · hr or more ～30Myug / Less than cm ² · hr D: Desorption rate is 30 μg / cm ² · hr or more The evaluation criteria A to C are acceptable levels of the present invention, and the ruthenium complex dye corresponding to the evaluation criteria A to C is practically adsorbed. It can be said that it has power.

  The above results are summarized in Table 2 below.

Example 3
[Manufacture of dye-sensitized solar cells]
Using the ruthenium complex dye synthesized in Example 1, a dye-sensitized solar cell 20 (5 mm × 5 mm scale) shown in FIG. 2 was produced. This manufacture was performed by the method shown below. About each manufactured dye-sensitized solar cell 20, the following performance was evaluated.

(Preparation of light receiving electrode precursor)
A fluorine-doped SnO ₂ conductive film (transparent conductive film 43, film thickness: 500 nm) was formed on a glass substrate (substrate 44, thickness 4 mm) to produce a conductive support 41. Then, the SnO ₂ conductive film, titania paste "18NR-T" a (Dyesol Inc.) was screen-printed, dried at 120 ° C.. Next, the titania paste “18NR-T” was screen-printed again and dried at 120 ° C. for 1 hour. Thereafter, the dried titania paste was baked in air at 500 ° C. to form a semiconductor layer 45 (layer thickness: 10 μm). Further, a titania paste “18NR-AO” (manufactured by DyeSol) was screen printed on the semiconductor layer 45 and dried at 120 ° C. for 1 hour. Thereafter, the dried titania paste was baked at 500 ° C., and a light scattering layer 46 (layer thickness: 5 μm) was formed on the semiconductor layer 45.
In this way, the photoreceptor layer 42 (light receiving surface area: 5 mm × 5 mm, layer thickness: 15 μm, unsupported ruthenium complex dye) is formed on the SnO ₂ conductive film, and the ruthenium complex dye is not supported. A light receiving electrode precursor was prepared.

(Dye adsorption)
Next, the ruthenium complex dyes Dye-1 to Dye-12 synthesized in Example 1 were supported on the photoreceptor layer 42 not supporting the ruthenium complex dye as follows. First, the ruthenium complex dye was synthesized in a 1: 1 (volume ratio) mixed solvent of t-butanol and acetonitrile dehydrated with magnesium ethoxide, and the ruthenium complex dye concentration was 2 × 10 ⁻⁴ mol / L. Then, 30 mol of deoxycholic acid as a co-adsorbent was added to 1 mol of the ruthenium complex dye to prepare each dye solution. Next, the light receiving electrode precursor was immersed in each dye solution at 25 ° C. for 45 hours, and then pulled up and dried.
In this manner, the light receiving electrode 40 in which different ruthenium complex dyes were supported on the light receiving electrode precursors was produced.

(Assembly of dye-sensitized solar cell)
As the counter electrode 48, a platinum electrode (Pt thin film thickness: 100 nm) having the same shape and size as the conductive support 41 was prepared. Moreover, iodine 0.1M (mol / L), lithium iodide 0.1M, 4-t-butylpyridine 0.5M, and 1,2-dimethyl-3-propylimidazolium iodide 0.6M were used as electrolyte solution. A liquid electrolyte was prepared by dissolving in acetonitrile. Further, a spacer S “Surlin” (trade name, manufactured by DuPont) having a shape matched to the size of the photoreceptor layer 42 was prepared.
Each of the light-receiving electrodes 40 and the counter electrode 48 manufactured as described above are thermocompression-bonded so as to face each other via the spacer S, and then the electrolyte solution injection port is interposed between the photoreceptor layer 42 and the counter electrode 48. The charge transfer layer 47 was formed by filling the liquid electrolyte. The outer periphery and the electrolyte injection port of the battery thus prepared were sealed and cured using Resin XNR-5516 (trade name, manufactured by Nagase Chemtech Co., Ltd.), and each dye-sensitized solar cell (Sample No. 101) To 112).

<Heat cycle test>
The dye-sensitized solar cell produced above was alternately put into a −10 ° C. freezer and a 40 ° C. thermostat every 2 hours, and cooling and warming were repeated to conduct a heat cycle test. About the dye-sensitized solar cell before the heat cycle test and the dye-sensitized solar cell after 24 hours of the heat cycle test, a solar simulator (manufactured by WACOM, trade name “WXS-85H”) is used to obtain an AM1.5 filter. The electric current which generate | occur | produces when 1000 W / m < ² > simulated sunlight is irradiated from the xenon lamp which passed through was measured. A value obtained by dividing the current value after the heat cycle test for 24 hours by the current value before the heat cycle test was calculated and used as a maintenance rate. Based on the maintenance rate of the dye-sensitized solar cell of sample number 101, the maintenance rate of the dye-sensitized solar cell of each sample number relative to the maintenance rate of the dye-sensitized solar cell of sample number 101 was evaluated according to the following evaluation criteria.

− Evaluation criteria −
A: 1.20 times or more of the maintenance rate of sample number 101 B: 1.10 times or more and less than 1.20 times the maintenance rate of sample number 101 C: greater than 1.00 times the maintenance rate of sample number 101 Less than 10 times D: 1.00 times or less of the maintenance rate of sample number 101 The evaluation criteria A to C are acceptable levels of the present invention.

  The above results are summarized in Table 2 below.

The following can be seen from the results in Table 2.
It was found that all of the ruthenium complex dyes of the present invention are excellent in adsorption stability on the surface of the semiconductor fine particles. Further, it was found that all the dye-sensitized solar cells using the ruthenium complex dye of the present invention have a small decrease rate of the current value with respect to repeated temperature change, and show stable battery performance.
On the other hand, a ruthenium complex dye (Dye-1) having a nitrogen-containing 5-membered ring-pyridine ring bidentate ligand having the substituent G ¹ at the 4-position with respect to the nitrogen atom that coordinates to ruthenium was used. In sample number 101 and sample number 104 using a ruthenium complex dye (Dye-4) in which the pyridine ring and -NCS (isothiocyanate group) in the nitrogen-containing 5-membered ring-pyridine ring bidentate ligand are in cis configuration In either case, neither the adsorption stability of the ruthenium complex dye on the surface of the semiconductor fine particles nor the heat cycle test was sufficient, and the passing level of this test was not satisfied.

  While the invention has been described in conjunction with the embodiments and drawings, it is not intended that the invention be limited in any detail to the description unless otherwise specified, but the spirit and scope of the invention as set forth in the appended claims I think that it should be interpreted widely without contradicting.

  This application claims priority based on Japanese Patent Application No. 2015-054037 filed in Japan on March 17, 2015, the contents of which are incorporated herein by reference. Capture as part.

DESCRIPTION OF SYMBOLS 1,41 Conductive support body 2,42 Photoconductor layer 21 Dye 22 Semiconductor fine particle 3,47 Charge transfer body layer 4,48 Counter electrode 5,40 Photosensitive electrode 6 External circuit 10 Photoelectric conversion element 100 Application of photoelectric conversion element to battery use System M operating means (eg electric motor)

20 Dye-sensitized solar cell 43 Transparent conductive film 44 Substrate 45 Semiconductor layer 46 Light scattering layer S Spacer

Claims (10)

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 (1) A photoelectric conversion element having semiconductor fine particles carrying a complex dye.
In the formula, M represents a hydrogen ion or a cation. X ¹ represents a nitrogen atom or CR ² . X ² represents a nitrogen atom when X ¹ is a nitrogen atom, and represents a nitrogen atom or CR ³ when X ¹ is CR ² . R ^{1 to} R ³ represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or a halogen atom. G ¹ represents a group represented by the following formula (G1).
In the formula, R ⁴ represents an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. m represents an integer of 1 to 3. n represents an integer of 0 to 2. Y ¹ represents an oxygen atom, a sulfur atom, NR ^f , a selenium atom, CR ^f ₂ or SiR ^f ₂ . R ^f represents a hydrogen atom or an alkyl group. * Represents a bond to the pyridine ring in formula (1). The photoelectric conversion element according to claim 1, wherein X ¹ is CH, and X ² is a nitrogen atom. The photoelectric conversion element according to claim ^1, wherein Y ¹ is a sulfur atom.   The photoelectric conversion element according to claim 1, wherein n is 0.   The dye-sensitized solar cell which has a photoelectric conversion element of any one of Claims 1-4. A ruthenium complex dye represented by the following formula (1).
In the formula, M represents a hydrogen ion or a cation. X ¹ represents a nitrogen atom or CR ² . X ² represents a nitrogen atom when X ¹ is a nitrogen atom, and represents a nitrogen atom or CR ³ when X ¹ is CR ² . R ^{1 to} R ³ represent a hydrogen atom, an alkyl group, a heteroaryl group, an aryl group, or a halogen atom. G ¹ represents a group represented by the following formula (G1).
In the formula, R ⁴ represents an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkynyl group, an alkenyl group, an alkoxy group, an alkylthio group, an amino group, a heteroaryl group or an aryl group. m represents an integer of 1 to 3. n represents an integer of 0 to 2. Y ¹ represents an oxygen atom, a sulfur atom, NR ^f , a selenium atom, CR ^f ₂ or Si (R ^f ) ₂ . R ^f represents a hydrogen atom or an alkyl group. * Represents a bond to the pyridine ring in formula (1). The ruthenium complex dye according to claim 6, wherein X ¹ is CH and X ² is a nitrogen atom. The ruthenium complex dye according to claim 6 or 7, wherein Y ¹ is a sulfur atom.   The ruthenium complex dye according to any one of claims 6 to 8, wherein n is 0.   The pigment | dye solution formed by melt | dissolving the ruthenium complex pigment | dye of any one of Claims 6-9.