JP5281863B2 - Dye, dye-sensitized solar cell and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye to become a constituting material of a dye-sensitized solar cell having a high conversion efficiency and excelling in the durability. <P>SOLUTION: The dye is represented by formula (1): ML<SP>1</SP>L<SP>2</SP>L<SP>3</SP>(M is a group 8 to 10 element in the long periodic table; and L<SP>1</SP>, L<SP>2</SP>and L<SP>3</SP>are bidentate ligands represented by respective specific formulae), and is, for example, a compound of formula (1a). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a dye, a dye-sensitized solar cell, and a method for producing the same. More specifically, the present invention provides a constituent material for a dye-sensitized solar cell that exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance. The present invention relates to a dye, a dye-sensitized solar cell, and a method for manufacturing the same.

  As interest in energy problems increases, research on solar cells that can efficiently convert light, particularly sunlight, into electricity has become active. For example, silicon-based solar cells using amorphous silicon or polycrystalline silicon have begun to spread.

  However, since silicon-based solar cells are expensive to manufacture and it is difficult to supply a large amount of high-purity silicon at a low price, it is generally said that there are limits to their widespread use.

  In recent years, therefore, dye-sensitized solar cells have attracted attention. Dye-sensitized solar cells have high power generation efficiency, relatively low manufacturing costs, inexpensive oxide semiconductors such as titanium oxide can be used as raw materials without being purified to high purity, and equipment used for manufacturing is inexpensive This has many advantages over silicon-based solar cells. Therefore, it is expected as a next-generation solar cell (see, for example, Patent Documents 1 and 2).

  The dye-sensitized solar cell includes an anode, a cathode, and an electrolyte, as in a normal battery. The cathode is a base material made of transparent conductive glass, and an oxide thin film formed on the surface thereof. And a structure in which a specific dye is adsorbed to the oxide thin film electrode.

  Conventionally, as a dye to be adsorbed on an oxide thin film electrode, a dye represented by the following formula (10) (a dye called “N719”) or a dye represented by the following formula (11) (“black dye”) (Referred to as non-patent documents 1 and 2).

（但し、上記式（１０）において、ＴＢＡ^＋はテトラブチルアンモニウムイオンである。）

(However, in the above formula (10), TBA ⁺ is a tetrabutylammonium ion.)

（但し、上記式（１１）において、ＴＢＡ^＋はテトラブチルアンモニウムイオンである。）

(However, in the above formula (11), TBA ⁺ is a tetrabutylammonium ion.)

US Pat. No. 4,927,721 International Publication No. 98/50393 Pamphlet J. et al. Am. Chem. Soc. 115, 6382-6390 (1993) J. et al. Am. Chem. Soc. , 123, 1613-1624 (2001)

  However, a dye-sensitized solar cell using the dye, particularly a dye-sensitized solar cell using N719, exhibits high conversion efficiency, but is not sufficiently satisfactory in terms of durability (weather resistance, heat resistance, etc.). There was no problem to be solved. That is, at present, there is no disclosure of a dye-sensitized solar cell that exhibits high conversion efficiency and is sufficiently satisfactory in terms of durability (weather resistance, heat resistance, etc.), and exhibits high conversion efficiency and durability (weather resistance). Development of a dye-sensitized solar cell having excellent properties, heat resistance, and the like is eagerly desired.

  The present invention has been made in view of such problems of the prior art, and is a constituent material of a dye-sensitized solar cell that exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance. The present invention provides a dye, a dye-sensitized solar cell using the dye, and a method for producing the dye-sensitized solar cell.

  As a result of intensive studies to solve the above problems, the present inventor has found that the problems of the prior art can be solved by using a dye having a compound having a specific structure as a ligand, and completed the present invention. Specifically, the present invention provides the following dyes, dye-sensitized solar cells, and methods for producing the same.

[1] A dye represented by the following general formula (1).
(1): ML ¹ L ² L ³
(However, M is an element of group 8-10 on the long periodic table, L ¹ is a bidentate ligand represented by the following general formula (2), and L ² is the following general formula (3). L ³ is a bidentate ligand represented by the following general formula (4).

（但し、前記一般式（２）において、Ｒ^１及びＲ^２は相互に独立して、下記一般式（２−１）〜（２−３）で示される構造のうちのいずれか１つである。）

(However, in the general formula (2), R ¹ and R ² are each independently one of the structures represented by the following general formulas (2-1) to (2-3). .)

（但し、前記一般式（２−１）において、ｎ^１は０〜５の整数であり、Ａはカチオンである。）

(However, in the general formula (2-1), ^{n 1} is an integer of 0 to 5, A is a cation.)

（但し、前記一般式（２−２）において、ｎ^２は１〜５の整数であり、Ａはカチオンである。）

(However, in the general formula (2-2), ^{n 2} is an integer from 1 to 5, A is a cation.)

（但し、前記一般式（２−３）において、ｎ^３は０〜５の整数であり、ｎ^４は１〜３の整数であり、Ａはカチオンである。）

(However, in the general formula (2-3), ^{n 3} is an integer from 0 to 5, ^{n 4} is an integer from 1 to 3, A is a cation.)

（但し、前記一般式（３）において、Ｘはハロゲン原子であり、ｎ^５は０〜２の整数である。）

(However, in the formula (3), X is a halogen atom, ^{n 5} is an integer of 0 to 2.)

（但し、前記一般式（４）において、ｎ^６及びｎ^７は相互に独立して、１〜３の整数であり、Ｒ^３及びＲ^４は相互に独立して、炭素数１〜２０の炭化水素基である。）

(However, the general formula (4), ^{n 6} and ^{n 7} are independently of one another, an integer from 1 to 3, ^{R 3} and ^{R 4} independently of one another, a hydrocarbon having 1 to 20 carbon atoms It is a hydrogen group.)

[2] The dye according to [1], wherein M in the general formula (1) is ruthenium.

[3] An anode, a cathode, and an electrolyte, wherein the cathode has a base material made of transparent conductive glass, and an oxide thin film electrode formed on the surface of the base material. A dye-sensitized solar cell in which the dye according to [1] or [2] is adsorbed on the oxide thin film electrode.

[4] A dye and base as described in [1] or [2] above, on a cathode member having a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. The manufacturing method of a dye-sensitized solar cell provided with the cathode formation process which contacts the pigment | dye solution containing this and obtains the cathode which made the said oxide thin film electrode adsorb | suck the said pigment | dye.

[5] The method for producing a dye-sensitized solar cell according to [4], wherein the dye solution having a base concentration of 0.0001 to 50 mN is used.

  The pigment | dye of this invention shows the effect that it becomes a constituent material of the dye-sensitized solar cell which shows high conversion efficiency and was excellent also in durability, such as a weather resistance and heat resistance.

  The dye-sensitized solar cell of the present invention exhibits a high conversion efficiency and an effect of being excellent in durability such as weather resistance and heat resistance.

  The method for producing a dye-sensitized solar cell of the present invention has an effect of producing a dye-sensitized solar cell that exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance. .

  Hereinafter, the best mode for carrying out the present invention will be described, but the present invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are also within the scope of the present invention based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

[1] Dye:
One embodiment of the coloring matter of the present invention is represented by the following general formula (1). Such a dye is a constituent material of a dye-sensitized solar cell that exhibits high conversion efficiency and is excellent in durability such as weather resistance and heat resistance.
(1): ML ¹ L ² L ³
(However, M is an element of group 8-10 on the long periodic table, L ¹ is a bidentate ligand represented by the following general formula (2), and L ² is the following general formula (3). L ³ is a bidentate ligand represented by the following general formula (4).

  In the general formula (1), “M” is a central atom, which is a metal atom composed of a group 8 to 10 element on the long periodic table. As the “Group 8-10 element”, specifically, the Group 8 element, iron, ruthenium, osmium, the Group 9 element, cobalt, rhodium, iridium, the Group 10 element, nickel, , Palladium, and platinum. The dye of the present invention is preferably one in which “M” is ruthenium. When M is ruthenium, there is an advantage that the color of the complex can be easily manipulated.

（但し、前記一般式（２）において、Ｒ^１及びＲ^２は相互に独立して、下記一般式（２−１）〜（２−３）で示される構造のうちのいずれか１つである。）

(However, in the general formula (2), R ¹ and R ² are each independently one of the structures represented by the following general formulas (2-1) to (2-3). .)

（但し、前記一般式（２−１）において、ｎ^１は０〜５の整数であり、Ａはカチオンである。）

(However, in the general formula (2-1), ^{n 1} is an integer of 0 to 5, A is a cation.)

（但し、前記一般式（２−２）において、ｎ^２は１〜５の整数であり、Ａはカチオンである。）

(However, in the general formula (2-2), ^{n 2} is an integer from 1 to 5, A is a cation.)

（前記一般式（２−３）において、ｎ^３は０〜５の整数であり、ｎ^４は１〜３の整数であり、Ａはカチオンである。）

(In the general formula (2-3), n ³ is an integer of 0 to 5, n ⁴ is an integer of 1 to 3, and A is a cation.)

（但し、前記一般式（３）において、Ｘはハロゲン原子であり、ｎ^５は０〜２の整数である。）

(However, in the formula (3), X is a halogen atom, ^{n 5} is an integer of 0 to 2.)

（但し、前記一般式（４）において、ｎ^６及びｎ^７は相互に独立して、１〜３の整数であり、Ｒ^３及びＲ^４は相互に独立して、炭素数１〜２０の炭化水素基である。）

(However, the general formula (4), ^{n 6} and ^{n 7} are independently of one another, an integer from 1 to 3, ^{R 3} and ^{R 4} independently of one another, a hydrocarbon having 1 to 20 carbon atoms It is a hydrogen group.)

  In general formulas (2-1) to (2-3), A is a cation, and among the cations, hydrogen ions, tetrabutylammonium ions, sodium ions, potassium ions, or lithium ions are preferable.

  Examples of the bidentate ligand (compound) represented by the general formula (3) described above include 2-phenylpyridine (a compound represented by the following formula (3a)) and the following general formula (3b). Can be mentioned.

（但し、上記一般式（３ｂ）において、Ｘはハロゲン原子である。）

(However, in the above general formula (3b), X is a halogen atom.)

  Specific examples of the compound represented by the following general formula (3b) include 2- (2,4-difluorophenyl) pyridine, 2- (2,4-dichlorophenyl) pyridine, and 2- (2,4-dibromo). And phenyl) pyridine.

  Specific examples of the dye of the present invention include compounds (dyes) represented by the following formulas (1a) to (1d).

  The dye of the present invention can be produced, for example, as follows. First, a first reaction solution is obtained by reacting a group 8-10 element on the long periodic table with a bidentate ligand (compound) represented by the general formula (2) in a solvent. Next, the bidentate ligand (compound) represented by the general formula (4) is added to the obtained first reaction solution and reacted to obtain a second reaction solution. Next, after removing the solvent from the obtained second reaction solution to obtain a precipitate, the obtained precipitate and the bidentate ligand (compound) represented by the general formula (3) are combined. Mix and react to obtain a third reaction solution. Next, the pigment | dye of this invention can be manufactured by adding alcohol and ether to the obtained 3rd reaction solution, and filtering the obtained precipitate. Examples of the alcohol include methanol and ethanol. Examples of ethers include diethyl ether and dibutyl ether. These may be used alone or in combination of two or more.

[2] Dye-sensitized solar cell:
One embodiment of the dye-sensitized solar cell of the present invention includes an anode, a cathode, and an electrolyte. The cathode is formed on a substrate made of transparent conductive glass and the surface of the substrate. An oxide thin film electrode. The dye of the present invention is adsorbed on the oxide thin film electrode. Such a dye-sensitized solar cell exhibits high conversion efficiency and is excellent in durability such as weather resistance and heat resistance.

  The “anode” is composed of a conductive material. The type of the constituent material is not particularly limited. For example, a material obtained by adhering a small amount of platinum or conductive carbon to the surface of a base material made of transparent conductive glass can be suitably used. As the “transparent conductive glass”, for example, glass made of tin oxide or indium-tin oxide (ITO) can be used.

  The “cathode” has a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. The oxide thin film electrode includes the dye of the present invention described above. Is adsorbed. As the “transparent conductive glass”, the same as the transparent conductive glass constituting the anode can be used. There is no restriction | limiting in particular about the shape of a "base material", For example, a plate-shaped thing etc. can be used.

  The “oxide thin film electrode” is a thin film made of an oxide. Examples of the oxide constituting the oxide thin film electrode include metal oxide, more specifically, titanium oxide, niobium oxide, zinc oxide, and oxide. Tin, tungsten oxide, indium oxide, etc. can be mentioned. Among these oxides, titanium oxide, niobium oxide and tin oxide are preferable, and titanium oxide is particularly preferable. This oxide thin film electrode is used in a state where the dye of the present invention is adsorbed. The method for adsorbing the dye is not particularly limited, but the method described in “Adsorption of dye” described later is preferably employed.

  The film thickness of the oxide thin film electrode is, for example, preferably 2 to 30 μm, more preferably 4 to 15 μm, and particularly preferably 6 to 12 μm. There exists a possibility that a pigment | dye may not adsorb | suck to an oxide thin film electrode as the said film thickness is less than 2 micrometers. On the other hand, if the thickness exceeds 30 μm, light may not be transmitted through the oxide thin film electrode.

The “electrolyte” is a liquid or solid electrolyte, and a solution containing such an electrolyte may be used. Among these, it is preferable to use a redox electrolyte. The “redox electrolyte” is a solution containing a substance constituting the redox system (oxidant, reducing agent). For example, a redox system (I ⁻ / I ³⁻ system) represented by the following formula (5) is used. A solution containing iodine and an imidazolium salt of iodine can be preferably used. As the solvent of this solution, an electrochemically inert substance such as acetonitrile or propionitrile can be suitably used.
(5): I ₃ ⁻ + 2e ⁻ ← → 3I ⁻ + I ₂

  The dye-sensitized solar cell of the present invention only needs to have an electrolyte between the anode and the cathode. Specifically, the container is filled with the electrolyte solution, and the anode and the cathode are opposed to each other in the electrolyte solution. Can be arranged and manufactured.

[3] Method for producing dye-sensitized solar cell:
One embodiment of a method for producing a dye-sensitized solar cell of the present invention is a cathode member having a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. And a cathode forming step of obtaining a cathode in which a dye solution containing the dye of the present invention and a base is brought into contact with the oxide thin film electrode to adsorb the dye. According to such a method, a dye-sensitized solar cell exhibiting high conversion efficiency and excellent durability such as weather resistance and heat resistance can be produced.

[3-1] Formation of oxide thin film electrode:
The cathode forming step provided in the method for producing a dye-sensitized solar cell of the present invention includes an operation of adsorbing the dye to the oxide thin film electrode constituting the cathode. Therefore, before adsorb | sucking a pigment | dye to an oxide thin film electrode, the member for cathodes which has an oxide thin film electrode is prepared. The method of forming the oxide thin film electrode of the cathode member is not particularly limited. For example, the oxide fine particles for constituting the oxide thin film electrode described above are oxidized by suspending in an appropriate dispersion medium. It is possible to form a product slurry, apply the slurry to the surface of a substrate made of transparent conductive glass to form a coating film, remove the solvent from the formed coating film, and then heat the slurry. it can. In this way, a negative electrode member can be obtained.

  In addition, as a transparent conductive glass used for a cathode formation process, the thing similar to the transparent conductive glass already mentioned above can be used suitably. Although there is no restriction | limiting in particular in the application quantity of an oxide slurry, It is preferable that it is the quantity from which the film thickness of the oxide thin film electrode obtained will be 6-20 micrometers.

[3-2] Dye adsorption:
The dye is adsorbed on the oxide thin film electrode, that is, the adsorption of the dye is performed according to the present invention for a cathode member having a substrate made of transparent conductive glass and an oxide thin film electrode formed on the surface thereof. This is carried out by bringing a dye solution containing the dye and the base into contact with each other.

  The “dye solution” is a solution containing the dye of the present invention, that is, the dye represented by the general formula (1) and a base. The dye solution preferably contains the dye of the present invention at a concentration of 0.1 to 10 mmol / L. By setting the concentration of the pigment to 0.1 mmol / L or more, the pigment can be sufficiently adsorbed on the oxide thin film electrode. On the other hand, when the amount is 10 mmol or less, it is possible to suppress a problem that the dyes are adsorbed. In order to exhibit such an effect more reliably, the concentration of the dye is more preferably 0.2 to 5 mmol / L, and particularly preferably 0.5 to 2 mmol / L.

  The base contained in the “dye solution” may be an inorganic base or an organic base.

  Examples of the “inorganic base” include alkali metal hydroxides, alkali metal carbonates, alkali metal sulfides, alkaline earth metal hydroxides, and the like.

  Examples of the “alkali metal hydroxide” include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. Examples of the “alkali metal carbonate” include lithium carbonate, sodium carbonate, potassium carbonate and the like. Examples of the “alkali metal sulfide” include lithium sulfide, sodium sulfide, potassium sulfide and the like. Examples of the “alkaline earth metal hydroxide” include calcium hydroxide and magnesium hydroxide.

  Examples of the “organic base” include primary to tertiary amine compounds, quaternary ammonium hydroxides, quaternary ammonium carbonates, quaternary ammonium sulfides, quaternary phosphonium hydroxides, and quaternary phosphonium compounds. Examples thereof include carbonates, quaternary phosphonium sulfides, nitrogen-containing heteroaromatic compounds having a nitrogen atom in the aromatic ring, and aromatic amine compounds.

  Examples of the “primary to tertiary amine compound” include primary amines such as methylamine and ethylamine; secondary amines such as dimethylamine and diethylamine; tertiary amines such as trimethylamine and triethylamine.

  Examples of the “quaternary ammonium hydroxide” include tetraethylammonium hydroxide and tetrabutylammonium hydroxide. Examples of the “quaternary ammonium carbonate” include tetramethylammonium carbonate and tetrabutylammonium carbonate. Examples of the “quaternary ammonium sulfide” include tetramethylammonium sulfate and tetrabutylammonium sulfate.

  Examples of the “quaternary phosphonium hydroxide” include tetramethylphosphonium hydroxide and tetrabutylphosphonium hydroxide. Examples of the “quaternary phosphonium carbonate” include tetramethylphosphonium carbonate, tetrabutylphosphonium carbonate, and the like. Examples of the “quaternary phosphonium sulfide” include tetramethylphosphonium sulfate, tetrabutylphosphonium sulfate, and the like.

  Examples of the “nitrogen-containing heteroaromatic compound” include pyridine, pyrrole, lutidine and the like. Examples of the “aromatic amine compound” include aniline, methylaniline, dimethylaniline and the like.

  Among these bases, it is preferable to use a Bronsted base, more preferably an organic base, particularly preferably a quaternary ammonium hydroxide, a quaternary ammonium carbonate, tetraethylammonium hydroxide, Most preferably, tetrabutylammonium hydroxide, tetramethylammonium carbonate, and tetrabutylammonium carbonate are used, and among the most preferable ones, tetraethylammonium hydroxide and tetrabutylammonium hydroxide are preferable.

  The dye solution preferably contains the above base at a concentration of 0.0001 to 50 mN, more preferably contains 0.001 to 20 mN, and particularly preferably contains 0.01 to 10 mN. .

  As a solvent for the dye solution, for example, water, a polar organic solvent, or a mixed solvent thereof is preferably used. Examples of the polar organic solvent include ether, alcohol, nitrile, amide, sulfoxide and the like.

  Examples of the “ether” include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether and the like. Examples of the “alcohol” include ethanol, methanol, isopropyl alcohol, butanol and the like. Examples of “nitrile” include acetonitrile, benzonitrile, propiononitrile, and the like. Examples of “amide” include dimethylformamide, dimethylacetamide and the like. Examples of the “sulfoxide” include dimethyl sulfoxide.

  Among these solvents, alcohol, nitrile, or amide is preferably used, and ethanol, methanol, butanol, or acetonitrile is more preferably used. Moreover, as a mixed solvent of a solvent, it is preferable to use the mixed solvent of alcohol and nitrile, and it is still more preferable to use the mixed solvent of butanol and acetonitrile.

  The method for bringing the cathode member into contact with the dye solution is not particularly limited, and examples thereof include a method of immersing the cathode member in the dye solution.

  When the cathode member is immersed in the dye solution, the immersion time is preferably 0.5 to 100 hours, more preferably 2 to 50 hours, and particularly preferably 12 to 24 hours. Moreover, it is preferable that the temperature in the case of immersion shall be 0-100 degreeC, and it is still more preferable that temperature shall be 10-50 degreeC.

[3-3] Formation of dye-sensitized solar cell:
In the method for producing a dye-sensitized solar cell of the present invention, after the cathode formation step, the container is filled with an electrolyte solution, and the anode and cathode facing each other are disposed in the electrolyte solution. A battery forming step for obtaining a battery can be performed.

  The electrolyte solution is a solution that already contains the electrolyte described above. Moreover, what was already mentioned above can be used suitably for an anode.

  When a spacer is sandwiched between the anode and the cathode, the anode and the cathode can be opposed to each other with a desired distance therebetween. Further, when a solid electrolyte is used as the electrolyte, for example, the cathode, the solid electrolyte, and the anode are sequentially laminated in this order so that the anode and the cathode are opposed to each other at a desired interval. it can.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

Example 1 [Synthesis of Dye]:
A compound represented by the following formula (1a) (hereinafter sometimes referred to as “dye T1”) was synthesized.

  First, after degassing under reduced pressure, 100 mg of (p-cymene) ruthenium (II) dichloride and 25 mg of anhydrous N, N-dimethylformamide in a nitrogen atmosphere and the following formula (6) dried under reduced pressure are represented. 148 mg of compound was added to prepare a solution, and this solution was placed under a nitrogen stream for 10 minutes. Thereafter, the above solution was stirred at 100 ° C. for 4 hours under a nitrogen atmosphere to obtain a first reaction solution. To this first reaction solution, 76 mg of a compound represented by the following formula (7) was added, and placed in a nitrogen stream for 10 minutes. Thereafter, the mixture was reacted at 150 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring to obtain a second reaction solution.

  After completion of the reaction, the second reaction solution is allowed to cool to room temperature, the solvent is distilled off, 5 mL of N, N-dimethylformamide is added, the solution is added dropwise to 100 mL of water, and the precipitate is collected. Obtained. After degassing under reduced pressure, 100 mg of the precipitate obtained by filtration and 2- (2,4-difluorophenyl) pyridine (general formula (3b)) dried under reduced pressure were added to 20 mL of ethylene glycol in a nitrogen atmosphere. Compound 42) was added and reacted to prepare a third reaction solution, which was placed in a nitrogen stream for 10 minutes. Under a nitrogen atmosphere, the third reaction solution was reacted at 160 ° C. for 2 hours with stirring to obtain a reaction solution. To this reaction solution, 266 mg of tetrabutylammonium hydroxide was added, and the mixture was reacted at 160 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring.

After completion of the reaction, the reaction solution was allowed to cool to room temperature, 0.1N nitric acid was added dropwise to adjust the pH to 5.0, and 50 mL of diethyl ether and 15 mL of methanol were added to obtain a precipitate. After allowing to stand overnight, filtration was performed to obtain a precipitate, and the obtained precipitate was dried to obtain 55 mg of a purified product. When this purified product was analyzed by ¹ H-NMR, it was confirmed that it was a compound (dye T1) represented by the above formula (1a). The analysis result of ¹ H-NMR of this example is shown below.

¹ H-NMR (CD ₃ OD, 400 MHz, δ (ppm)); δ = 9.05 (1H), 8.95 (1H), 8.60 (2H), 8.30 (2H) 8.10 ( 1H), 7.90 (1H), 7.85 (1H), 7.80 (1H), 7.78 (1H), 7.68 (1H), 7.62 (1H), 7.58 (1H) ), 7.40 (1H), 7.38 (1H), 7.25 (1H), 7.00 (1H), 6.85 (4H), 6.10 (1H), 3.25 (12H) 3.24 (1H), 3.22 (12H), 3.19 (12H), 3.02 (16H), 2.56-1.25 (36H)

(Example 2)
A compound represented by the following formula (1c) (hereinafter sometimes referred to as “dye T2”) was synthesized.

  First, after degassing under reduced pressure, 100 mg of (p-cymene) ruthenium (II) dichloride and 25 mg of anhydrous N, N-dimethylformamide in a nitrogen atmosphere and the above formula (6) dried under reduced pressure are represented. A solution was prepared by adding 148 mg of the compound and placed under a nitrogen stream for 10 minutes. Thereafter, the solution was reacted at 100 ° C. for 4 hours with stirring in a nitrogen atmosphere to obtain a first reaction solution. To this first reaction solution, 76 mg of a compound represented by the following formula (8) was added, and placed in a nitrogen stream for 10 minutes. Thereafter, the mixture was reacted at 150 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring to obtain a second reaction solution.

  After completion of the reaction, the second reaction solution is allowed to cool to room temperature, the solvent is distilled off, 5 mL of N, N-dimethylformamide is added, the solution is added dropwise to 100 mL of water, and the precipitate is collected. Obtained. After degassing under reduced pressure, 100 mg of the precipitate obtained by filtration and 2- (2,4-difluorophenyl) pyridine (general formula (3b)) dried under reduced pressure were added to 20 mL of ethylene glycol in a nitrogen atmosphere. Compound 42) was added and reacted to prepare a third reaction solution, which was placed in a nitrogen stream for 10 minutes. Under a nitrogen atmosphere, the third reaction solution was reacted at 160 ° C. for 2 hours with stirring to obtain a reaction solution. To this reaction solution, 266 mg of tetrabutylammonium hydroxide was added, and the mixture was reacted at 160 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring.

After completion of the reaction, the reaction solution was allowed to cool to room temperature, 0.1N nitric acid was added dropwise to adjust the pH to 5.0, and 50 mL of diethyl ether and 15 mL of methanol were added to obtain a precipitate. After leaving still overnight, it filtered, the deposit was obtained, and the obtained deposit was processed by the method according to Example 1, and 55 mg of purified products were obtained. When this purified product was analyzed by ¹ H-NMR, it was confirmed that it was a compound represented by the above formula (1c) (dye T2). The analysis result of ¹ H-NMR of this example is shown below.

¹ H-NMR (CD ₃ OD, 400 MHz, δ (ppm)); δ = 9.05 (1H), 8.95 (1H), 8.60 (2H), 8.30 (2H) 8.10 ( 1H), 8.05 (2H), 7.90 (1H), 7.87 (2H), 7.85 (1H), 7.80 (1H), 7.78 (1H), 7.68 (1H) ), 7.62 (1H), 7.58 (1H), 7.40 (1H), 7.38 (1H), 7.25 (1H), 7.00 (1H), 6.85 (4H) 6.10 (1H), 3.25 (12H), 3.24 (1H), 3.22 (12H), 3.19 (12H), 3.02 (16H), 2.56-1.25 (36H)

  A compound represented by the following formula (1d) (hereinafter sometimes referred to as “dye T3”) was synthesized.

  First, after degassing under reduced pressure, 100 mg of (p-cymene) ruthenium (II) dichloride and 25 mg of anhydrous N, N-dimethylformamide in a nitrogen atmosphere and the above formula (6) dried under reduced pressure are represented. 148 mg of compound was added to prepare a solution, and this solution was placed under a nitrogen stream for 10 minutes. Thereafter, the above solution was stirred at 100 ° C. for 4 hours under a nitrogen atmosphere to obtain a first reaction solution. To this first reaction solution, 76 mg of a compound represented by the following formula (9) was added, and placed in a nitrogen stream for 10 minutes. Thereafter, the mixture was reacted at 150 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring to obtain a second reaction solution.

  After completion of the reaction, the second reaction solution is allowed to cool to room temperature, the solvent is distilled off, 5 mL of N, N-dimethylformamide is added, the solution is added dropwise to 100 mL of water, and the precipitate is collected. Obtained. After degassing under reduced pressure, 100 mg of the precipitate obtained by filtration and 2- (2,4-difluorophenyl) pyridine (general formula (3b)) dried under reduced pressure were added to 20 mL of ethylene glycol in a nitrogen atmosphere. Compound 42) was added and reacted to prepare a third reaction solution, which was placed in a nitrogen stream for 10 minutes. Under a nitrogen atmosphere, the third reaction solution was reacted at 160 ° C. for 2 hours with stirring to obtain a reaction solution. To this reaction solution, 266 mg of tetrabutylammonium hydroxide was added, and the mixture was reacted at 160 ° C. for 4 hours under a nitrogen atmosphere with continuous stirring.

After completion of the reaction, the reaction solution was allowed to cool to room temperature, 0.1N nitric acid was added dropwise to adjust the pH to 5.0, and 50 mL of diethyl ether and 15 mL of methanol were added to obtain a precipitate. After leaving still overnight, it filtered, the deposit was obtained, and the obtained deposit was processed by the method according to Example 1, and 55 mg of purified products were obtained. When this purified product was analyzed by ¹ H-NMR, it was confirmed that it was a compound represented by the formula (1d) (dye T3). The analysis result of ¹ H-NMR of this example is shown below.

¹ H-NMR (CD ₃ OD, 400 MHz, δ (ppm)); δ = 9.04 (1H), 8.95 (1H), 8.58 (2H), 8.28 (2H) 8.10 ( 1H), 8.05 (2H), 7.90 (1H), 7.87 (2H), 7.84 (1H), 7.80 (1H), 7.78 (1H), 7.65 (1H) ), 7.62 (1H), 7.58 (1H), 7.40 (1H), 7.38 (1H), 7.25 (1H), 7.00 (1H), 6.85 (4H) 6.10 (1H), 3.25 (12H), 3.24 (1H), 3.22 (12H), 3.19 (12H), 3.02 (16H), 2.56-1.25 (36H)

(Example 4) [Production of dye-sensitized solar cell]:
(1) Production of anode:
First, platinum was sintered on the surface of a base material (thickness 4 mm, made of tin oxide, resistance value = 10 Ω / cm ² ) made of transparent conductive glass to obtain an anode.

(2) Production of oxide thin film electrode:
In a mixed medium of 0.4 mL of acetylacetone and 20 mL of ion-exchanged water, 12 g of titanium oxide fine particles and 0.2 g of a dispersant (trade name “Triton X-100”, manufactured by Aldrich) were added to prepare an oxide slurry. By applying this oxide slurry to the surface of the substrate made of the same transparent conductive glass as used in the production of the anode, and heating in an air atmosphere at 500 ° C. for 0.5 hour, the transparent conductive glass An oxide thin film electrode made of titanium oxide was formed on the surface of the base material made of to obtain a cathode member.

(3) Preparation of dye solution:
The dye T1 synthesized in Example 1 and the base were dissolved in ethanol to prepare a dye solution having a dye concentration of 0.5 mmol / L.

(4) Production of cathode:
The cathode member was immersed in the dye solution at 23 ° C. for 24 hours to adsorb the dye to the oxide thin film electrode of the cathode member to produce a cathode.

(5) Production of electrolyte solution:
Acetonitrile / valeronitrile mixed solvent (volume ratio: 85/15), guanidinium thiocyanate 0.1 mol / L, iodine 0.03 mol / L, 1-butyl-3-methylimidazolium iodonium salt 0.6 mol / L and t-butylpyridine were dissolved at a concentration of 0.5 mol / L to prepare an electrolyte solution E1 (shown as “E1” in Table 1).

(6) Production of dye-sensitized solar cell:
First, the anode and the cathode were placed in a container so that the platinum sintered surface of the anode and the oxide thin film electrode forming surface of the cathode face each other and the distance between the electrodes was 25 μm. Then, electrolyte solution E1 was inject | poured in this container, and the dye-sensitized solar cell was manufactured. The following evaluation was performed about the manufactured dye-sensitized solar cell.

Conversion efficiency (power generation efficiency):
The produced dye-sensitized solar cell was irradiated with pseudo-sunlight at an illuminance of 100 mW / cm ² using a solar simulator, and the conversion efficiency (%) was measured. In addition, regarding the measured conversion efficiency (%), when the conversion efficiency is 9% or more, “Good” (good), when less than 9% and 6% or more, “△”, when less than 6%, Evaluation was performed as “x” (defect).

  The dye-sensitized solar cell of this example had a conversion efficiency (power generation efficiency) of 9.56%, and the evaluation was “◯”. The evaluation results are shown in Table 1.

(Examples 5 to 9, Comparative Examples 1 and 2)
A dye-sensitized solar cell was produced in the same manner as in Example 4 except that the dye and electrolyte solution shown in Table 1 were used. The conversion efficiency (power generation efficiency) of the manufactured dye-sensitized solar cell was evaluated. The evaluation results are shown in Table 1.

  In Table 1, “N719” is a commercially available dye “N719” (a dye represented by the above formula (12)). “E2” is acetonitrile / valeronitrile mixed solvent (volume ratio: 85/15), lithium iodonium salt 0.1 mol / L, iodine 0.05 mol / L, and 1-butyl-3-methylimidazolium. An electrolyte solution produced by dissolving an iodonium salt at a concentration of 0.6 mol / L.

(Examples 10 to 12, Comparative Example 3)
A dye-sensitized solar cell was produced in the same manner as in Example 4 except that the dye and electrolyte solution shown in Table 2 were used. The following evaluation was performed about the manufactured dye-sensitized solar cell.

Conversion efficiency and durability:
The produced dye-sensitized solar cell was held under an atmosphere of 333 K, 100 mW / cm ² . The dye-sensitized solar cell after holding is irradiated with pseudo sunlight at an illuminance of 100 mW / cm ² for 30 days using a solar simulator, and the initial conversion efficiency (conversion efficiency A) and the conversion efficiency after 30 days have passed. (Conversion efficiency B) was measured. When the value of conversion efficiency A (shown as “conversion efficiency (initial)” in Table 2) is 4% or more, it is “◯” (good), and when it is less than 4%, “×” (bad). As evaluated. Moreover, when the value of the conversion efficiency B (shown as “conversion efficiency (after 30 days)” in Table 2) is 2% or more, it is “◯” (good), and when it is less than 2%, “×” ( Bad).

  Further, the percentage of the conversion efficiency B with respect to the conversion efficiency A (shown as “B / A (%)” in Table 2) is calculated from the measured value of the conversion efficiency A and the value of the conversion efficiency B to evaluate durability. Went. The evaluation criteria were “◯” (good) when the percentage value was 60% or more, and “x” (bad) when the percentage value was less than 60%. The evaluation results are shown in Table 2.

  In Table 2, “E3” means 3-methoxypropionitrile, guanidinium thiocyanate 0.1 mol / L, iodine 0.15 mol / L, 1-methyl 3-propylimidazolium iodonium salt 1 It is an electrolyte solution produced by dissolving 0.0 mol / L of N-butylbenzimidazole at a concentration of 0.5 mol / L.

  As shown in Table 1, the dye-sensitized solar cells of Examples 4 to 9 using the dyes of Examples 1 to 3 (dyes T1 to T3) were dye-sensitized of Comparative Examples 1 and 2 using N719. It was confirmed that the conversion efficiency was as high as that of the solar cell. Moreover, as shown in Table 2, the dye-sensitized solar cells of Examples 10 to 12 using the dyes of Examples 1 to 3 (Dyes T1 to T3) are dye-sensitized of Comparative Example 3 using N719. High durability compared to solar cells.

  The dye of the present invention can be suitably used as a material for a dye-sensitized solar cell.

  Since the dye-sensitized solar cell of the present invention exhibits high conversion efficiency and is excellent in durability such as weather resistance and heat resistance, it can be suitably used as a next-generation solar cell that replaces a silicon-based solar cell.

  Since the method for producing a dye-sensitized solar cell of the present invention exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance, a next-generation dye-sensitized solar cell that replaces a silicon-based solar cell is preferably used. Can be manufactured.

Claims (5)

The pigment | dye represented by following General formula (1).
(1): ML ¹ L ² L ³
(However, M is an element of group 8-10 on the long periodic table, L ¹ is a bidentate ligand represented by the following general formula (2), and L ² is the following general formula (3). L ³ is a bidentate ligand represented by the following general formula (4).

(However, in the general formula (2), R ¹ and R ² are each independently one of the structures represented by the following general formulas (2-1) to (2-3). .)

(However, in the general formula (2-1), ^{n 1} is an integer of 0 to 5, A is a cation.)

(However, in the general formula (2-2), ^{n 2} is an integer from 1 to 5, A is a cation.)

(However, in the general formula (2-3), ^{n 3} is an integer from 0 to 5, ^{n 4} is an integer from 1 to 3, A is a cation.)

(However, in the formula (3), X is a halogen atom, ^{n 5} is an integer of 0 to 2.)

(However, the general formula (4), ^{n 6} and ^{n 7} are independently of one another, an integer from 1 to 3, ^{R 3} and ^{R 4} independently of one another, a hydrocarbon having 1 to 20 carbon atoms It is a hydrogen group.)   The dye according to claim 1, wherein M in the general formula (1) is ruthenium. An anode, a cathode, and an electrolyte;
The said cathode has the base material which consists of transparent conductive glass, and the oxide thin film electrode formed in the surface of the said base material, The said oxide thin film electrode is described in Claim 1 or 2. A dye-sensitized solar cell in which the dye is adsorbed.   A dye solution containing the dye and the base according to claim 1 or 2 on a cathode member having a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. A method for producing a dye-sensitized solar cell, comprising a cathode forming step of obtaining a cathode in which the dye is adsorbed to the oxide thin film electrode by contact.   The manufacturing method of the dye-sensitized solar cell of Claim 4 using the said dye solution whose density | concentration of the said base is 0.0001-50mN.