KR100996236B1 - A NOBLE Ru-TYPE SENSITIZERS AND METHOD FOR PREPARING OF IT - Google Patents

Abstract

The present invention relates to a novel ruthenium (Ru) -based dye and a method for manufacturing the same, and more particularly, it is used as a dye in a dye-sensitized solar cell, and shows a remarkably improved photoelectric conversion efficiency than a conventional dye. The present invention relates to a dye and a method for manufacturing the same, which enhance the binding force with titanium dioxide, and have excellent short circuit photocurrent density (Jsc) and molar extinction coefficient, thereby greatly improving the efficiency of a solar cell.

Solar cell, dye-sensitized, dye, ruthenium, photoelectric conversion element

Description

New ruthenium-based dyes and preparation method thereof {A NOBLE Ru-TYPE SENSITIZERS AND METHOD FOR PREPARING OF IT}

1 shows the J-V curve and the IPCE index of a solar cell manufactured using D5 and D6 dyes of the present invention and N3 dye, which is a conventional dye.

(A), (b) and (c) of FIG. 2 are respectively absorbed after coating D5, D6 and N3 on a DMF solution, a TiO ₂ film, and immersing the film in an aqueous KOH solution for 3 days and then removing the dye. It is a measurement of the spectrum.

The present invention relates to a novel ruthenium-based dye and a method for manufacturing the same, and in particular, it is used as a dye in a dye-sensitized solar cell, which shows a remarkably improved photoelectric conversion efficiency than a conventional dye, and a binding force with titanium dioxide. , A ruthenium-based dye and a method for manufacturing the same, and a photoelectric conversion device and a dye-sensitized solar which can be used to improve the efficiency of a solar cell due to excellent short circuit photocurrent density (Jsc) and molar extinction coefficient. It relates to a battery.

Since the development of the dye-sensitized nanoparticle titanium oxide solar cell by the team of Michael Gratzel of the Swiss National Lausanne Institute of Advanced Technology (EPFL) in 1991, much work has been done in this area. Dye-sensitized solar cells have the potential to replace conventional amorphous silicon solar cells because their manufacturing cost is significantly lower than conventional silicon-based solar cells. Unlike silicon solar cells, dye-sensitized solar cells absorb visible light It is a photoelectrochemical solar cell mainly composed of a dye molecule capable of generating electron-hole pairs and a transition metal oxide that transfers generated electrons.

Typical dyes used in dye-sensitized solar cells include the following compounds.

However, it is still required to increase the efficiency and durability of the solar cell by increasing the bonding force with the oxide semiconductor fine particles, the photoelectric conversion efficiency, the short circuit photocurrent density (Jsc) and the molar extinction coefficient in comparison with the dyes. Research is needed.

In order to solve the problems of the prior art as described above, the present invention shows a remarkably improved photoelectric conversion efficiency than the conventional dye, enhances the bonding force with the oxide semiconductor fine particles, JSC (short circuit photocurrent density) and the molar extinction coefficient is excellent It is an object of the present invention to provide a dye and a method for producing the same that can greatly improve the efficiency of a solar cell.

In addition, the present invention exhibits a remarkably improved photoelectric conversion efficiency, including the dye, the bonding strength with the oxide semiconductor fine particles, the dye-sensitized photoelectric conversion element and excellent efficiency of the short circuit photocurrent density (Jsc) and the molar extinction coefficient is significantly improved It is an object to provide a solar cell.

In order to achieve the above object, the present invention provides a ruthenium (Ru) -based dye represented by the following formula (1).

[Formula 1]

In Formula 1, the a1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group,

In addition, X and Y are each independently a methyl or a compound represented by the formula (2), at least one of X and Y is a compound represented by the formula (2),

[Formula 2]

In Formula 2, the b1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group, and R may be the same or different. Each independently hydrogen or an alkyl group having 1 to 15 carbon atoms.

In another aspect, the present invention provides a method for producing a dye represented by the formula (1) characterized in that the compound of formula (4) or (5) is reacted with the compound of formula (3), formula (6) and formula (7).

(3)

RuCl ₂ ( p -cymene) ₂

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

NH ₄ NCS

In Formulas 3, 4, 5, 6, and 7 a1, b1 and R are as defined above.

In another aspect, the present invention provides a dye-sensitized photoelectric conversion device comprising an oxide semiconductor fine particles supported by a compound represented by the formula (1).

In another aspect, the present invention provides a dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention have excellent durability by supporting the compound represented by Chemical Formula 1 on oxide semiconductor fine particles by strongly binding to oxide semiconductor fine particles, and having excellent durability, photoelectric conversion efficiency, short circuit photocurrent density (Jsc) and molar extinction coefficient. It was confirmed that the high efficiency than the existing dye-sensitized solar cell was high and completed the present invention.

Ruthenium (Ru) -based dye of the present invention is characterized by represented by the following formula (1).

[Formula 1]

In Formula 1, the a1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group,

In addition, X and Y are each independently a methyl or a compound represented by the formula (2), at least one of X and Y is a compound represented by the formula (2),

[Formula 2]

In Formula 2, the b1 ring may have hydrogen or one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group, and R may be the same It may be different, each independently hydrogen or an alkyl group having 1 to 15 carbon atoms, preferably R is methyl, ethyl, propyl, butyl or pentyl.

More preferably, the compound represented by the formula (1) is preferably the following compound.

In another aspect, the present invention provides a method for producing a dye represented by the formula (1), the dye represented by the formula (1) is a double reaction by reacting a compound of formula 3 or 4 with a compound of formula 5, 6 and 7 It can be prepared via the Wadsworth-Emmons reaction.

(3)

RuCl ₂ ( p -cymene) ₂

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

NH ₄ NCS

In Formulas 3, 4, 5, 6, and 7 a1, b1 and R are as defined above.

 Preferably, the dye of the present invention may be prepared through a process represented by the following scheme.

Scheme 1

In Scheme 1, 4 and 5 represent compounds of Formula 4 and Formula 5, respectively.

In addition, the present invention provides a dye-sensitized photoelectric conversion device, the dye-sensitized photoelectric conversion device is characterized in that the dye represented by the formula (1) on the oxide semiconductor fine particles. The present invention is a dye-sensitized photoelectric conversion device in addition to using the dye represented by the formula (1) can be applied to the method of manufacturing a dye-sensitized photoelectric conversion device for a solar cell using a conventional dye, of course, preferably the present invention The dye-sensitized photoelectric conversion device may be prepared by fabricating a thin film of an oxide semiconductor on a substrate using oxide semiconductor fine particles, and then supporting the dye of the present invention on the thin film.

In this invention, it is preferable that the surface is electroconductive as a board | substrate which provides the thin film of an oxide semiconductor, and what is marketed can also be used. As a specific example, conductive metal oxides such as tin oxide coated with indium, fluorine, and antimony on the surface of glass or transparent polymer materials such as polyethylene terephthalate or polyethersulfone, or metal thin films such as steel, silver, and gold What formed this can be used. In this case, the conductivity is usually preferably 1000 Ω or less, particularly preferably 100 Ω or less.

As the fine particles of the oxide semiconductor, a metal oxide is preferable. As specific examples, oxides such as titanium, tin, zinc, tungsten, zirconium, gallium, indium, yttrium, niobium, tantalum and vanadium can be used. Of these, oxides such as titanium, tin, zinc, niobium and indium are preferable, and among these, titanium oxide, zinc oxide, and tin oxide are more preferable, and titanium oxide is most preferable. The oxide semiconductor may be used alone, or may be mixed or coated on the surface of the semiconductor.

The particle diameter of the fine particles of the oxide semiconductor is preferably 1 to 500 nm, more preferably 1 to 100 nm as the average particle diameter. In addition, the fine particles of the oxide semiconductor may be mixed with a large particle size and a small particle size, or may be used as a multilayer.

The oxide semiconductor thin film is a method of forming oxide semiconductor fine particles into a thin film directly on a substrate by spray spraying, a method of electrically depositing a semiconductor fine particle thin film using a substrate as an electrode, a slurry of semiconductor fine particles or semiconductor fine particles such as a semiconductor alkoxide. After applying the paste containing the fine particles obtained by hydrolyzing the precursor onto the substrate, it can be produced by a method of drying, curing or baking, and a method of applying the paste onto the substrate is preferred. In the case of this method, a slurry can be obtained by disperse | distributing the oxide semiconductor microparticles | fine-particles which are secondary aggregated so that an average primary particle diameter may be 1-200 nm in a dispersion medium by a conventional method.

The dispersion medium for dispersing the slurry can be used without particular limitation so long as it can disperse the semiconductor fine particles, and alcohols such as water and ethanol, ketones such as acetone and acetylacetone, or hydrocarbons such as hexane can be used, and these can be mixed and used. Among them, it is preferable to use water among them in order to reduce the viscosity change of the slurry. Moreover, a dispersion stabilizer can be used for the purpose of stabilizing the dispersion state of oxide semiconductor microparticles | fine-particles. As a specific example of the dispersion stabilizer which can be used, acids, such as acetic acid, hydrochloric acid, nitric acid, or acetylacetone, acrylic acid, polyethyleneglycol, polyvinyl alcohol, etc. are mentioned, for example.

The substrate coated with the slurry can be fired, and its firing temperature is at least 100 ° C, preferably at least 200 ° C, and the upper limit is generally below the melting point (softening point) of the substrate, and usually the upper limit is 900 ° C, preferably 600. It is below ℃. In the present invention, the firing time is not particularly limited, but is usually within 4 hours.

In the present invention, the thickness of the thin film on the substrate is preferably 1 to 200 µm, preferably 1 to 50 µm. In the case of firing, some thin layers of the oxide semiconductor fine particles are welded, but such welding is not particularly troubled for the present invention.

In addition, the oxide semiconductor thin film may be subjected to secondary treatment. For example, the performance of a semiconductor thin film may be improved by directly depositing a thin film for each substrate and drying or refiring it in a solution such as an alkoxide, chloride, nitride, or sulfide of the same metal as the semiconductor. Examples of the metal alkoxide include titanium ethoxide, titanium isopropoxide, titanium t-butoxide, n-dibutyl-diacetyl tin and the like, and an alcohol solution thereof can be used. As a chloride, titanium tetrachloride, tin tetrachloride, zinc chloride, etc. are mentioned, for example, The aqueous solution can be used. The oxide semiconductor thin film thus obtained is composed of fine particles of an oxide semiconductor.

In addition, the method of supporting the dye on the oxide semiconductor fine particles formed in the thin film phase in the present invention is not particularly limited, as a specific example by dispersing a solution obtained by dissolving the dye represented by the formula (1) in a solvent capable of dissolving, or dye The method of immersing the board | substrate with which the said oxide semiconductor thin film was provided in the obtained dispersion liquid is mentioned. The concentration in the solution or dispersion can be appropriately determined by the dye. The deposition time is usually from room temperature to the boiling point of the solvent, and the deposition time is about 1 minute to 48 hours. Specific examples of the solvent that can be used to dissolve the dye include methanol, ethanol, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, t-butanol and the like. The dye concentration of the solution is usually preferably 1 × 10 ⁻⁶ M to 1 M, preferably 1 × 10 ⁻⁵ M to 1 × 10 ⁻¹ M. In this way, the photoelectric conversion element of this invention which has oxide semiconductor microparticles | fine-particles on the thin film sensitized with dye can be obtained.

The dye represented by the formula (1) supported by the present invention may be one kind or may be mixed in several kinds. In addition, when mixing, only the dye of this invention can be used and other dye and metal complex dye can be mixed. Examples of metal complex dyes that can be mixed are not particularly limited, but MK Nazeeruddin, A.Kay, I.Rodicio, R.Humphry-Baker, E.Muller, P.Liska, N.Vlachopoulos, M.Gratzel, J. Am . Chem. Soc., Vol. 115, pp. 6382 (1993). Ruthenium complexes, quaternary salts thereof, phthalocyanine, porphyrin, and the like are preferred, and organic dyes used for mixing are metal-free phthalocyanine, porphyrin, cyanine, merocyanine, oxo. Methine dyes such as knol, triphenylmethane and acrylic acid dyes described in WO2002 / 011213, and dyes such as xanthene, azo, anthraquinone and perylene. In the case of using two or more kinds of dyes, the dyes may be adsorbed onto the semiconductor thin film in sequence, or may be mixed and dissolved and adsorbed.

In the present invention, when the dye is supported on the thin film of the oxide semiconductor fine particles, it is preferable to support the dye in the presence of the inclusion compound in order to prevent the dyes from bonding. Examples of the inclusion compound include carboxylic acids such as deoxycholic acid, dehydrodeoxycholic acid, kenodeoxycholic acid, methyl ester of cholate, and sodium cholate, steroidal compounds such as polyethylene oxide and cholic acid, crown ether, cyclodextrin, and calix arene, Polyethylene oxide and the like can be used.

After the dye is supported, the semiconductor electrode surface can be treated with an amine compound such as 4-t-butyl pyridine or a compound having an acidic group such as acetic acid or propionic acid. As a treatment method, for example, a method of dipping a substrate provided with a thin film of semiconductor fine particles in which a dye is supported in an amine ethanol solution may be used.

In another aspect, the present invention provides a dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device, using a dye-sensitized photoelectric conversion device using the oxide semiconductor fine particles carrying the dye represented by the formula (1) In addition to the conventional methods for manufacturing a solar cell using a conventional photoelectric conversion element can be applied, of course, a photoelectric conversion element electrode (cathode), the charging of the dye represented by the formula (1) on the oxide semiconductor fine particles It may be composed of an electrode (anode), a redox electrolyte, a hole transport material, or a p-type semiconductor.

Preferably, as an example of a specific method of manufacturing a dye-sensitized solar cell of the present invention, the method includes coating a titanium oxide paste on a conductive transparent substrate, baking a substrate coated with a paste to form a titanium oxide thin film, and a titanium oxide thin film. Impregnating the formed substrate into a mixed solution in which the dye represented by Chemical Formula 1 is dissolved to form a titanium oxide film electrode on which the dye is adsorbed, and providing a second glass substrate having a counter electrode formed thereon, and a second glass. Forming a hole penetrating the substrate and the counter electrode, placing a thermoplastic polymer film between the counter electrode and the titanium oxide film electrode on which the dye is adsorbed, and performing a heat compression process to perform the counter electrode and the titanium oxide film. Bonding the electrodes to the thermoplastic polymer film between the counter electrode and the titanium oxide film electrode through the holes; It is good to prepare through the step of injecting an electrolyte and the step of sealing the thermoplastic polymer.

Examples of the forms of the redox electrolyte, the hole transport material, the p-type semiconductor, and the like include liquids, coagulated bodies (gels and gels), solids, and the like. As liquids, redox electrolytes, dissolved salts, hole transport materials, p-type semiconductors, and the like are dissolved in a solvent, and at room temperature, dissolved salts, etc., in the case of coagulated bodies (gel and gel), these are polymer matrix or low molecular gelling agent. And the like and the like. As a solid thing, a redox electrolyte, a dissolution salt, a hole transport material, a p-type semiconductor, etc. can be used.

Examples of the hole transport material include amine-induced amines, conductive polymers such as polyacetylene, polyaniline, and polythiophene, and those using discotech liquid crystal phases such as triphenylene compounds. Moreover, CuI, CuSCN, etc. can be used as a p-type semiconductor. It is preferable that the counter electrode has conductivity and catalyzes the reduction reaction of the redox electrolyte. For example, platinum, carbon, rhodium, ruthenium, or the like deposited on glass or a polymer film, or coated with conductive fine particles can be used.

As a redox electrolyte used in the solar cell of the present invention, a halogen redox electrolyte composed of halogen compounds having halogen ions as counter ions and halogen molecules, ferrocyanate-ferrocyanate, ferrocene-ferricinium ions, cobalt complexes and the like Metal redox-based electrolytes such as metal complexes, organic redox-based electrolytes such as alkylthiol-alkyldisulfides, viologen dyes, and hydroquinone-quinones, and the like, and halogen-redox electrolytes are preferable. As a halogen molecule in a halogen redox electrolyte composed of a halogen compound-halogen molecule, an iodine molecule is preferable. As a halogen compound having a halogen ion as a large ion, halogenated metal salts such as LiI, NaI, KI, CaI ₂ , MgI ₂ and CuI, or organic ammonium salts of halogens such as tetraalkylammonium iodine, imidazolium iodine and pyridium iodine, Or I ₂ can be used.

In addition, when the redox electrolyte is configured in the form of a solution containing the same, an electrochemically inert one may be used as the solvent. Specific examples include acetonitrile, propylene carbonate, ethylene carbonate, 3-methoxy propionitrile, methoxy acetonitrile, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, butyrolactone, dimethoxyethane, dimethyl carbonate, 1,3-dioxolane, methylformate, 2-methyltetrahydrofuran, 3-methoxy-oxazolidin-2-one, sulfolane, tetrahydrofuran, water, and the like, in particular acetonitrile, Propylene carbonate, ethylene carbonate, 3-methoxy propionitrile, ethylene glycol, 3-methoxy-oxazolidin-2-one, butyrolactone and the like are preferable. The solvents may be used alone or in combination. In the case of a gel positive electrolyte, one containing an electrolyte or an electrolyte solution in a matrix such as an oligomer and a polymer, or one containing an electrolyte or an electrolyte solution in the same manner as a starch gelling agent can be used. The concentration of the redox electrolyte is preferably 0.01 to 99% by weight, more preferably 0.1 to 30% by weight.

In the solar cell of the present invention, a counter electrode (anode) is disposed in a photoelectric conversion element (cathode) on which a dye is supported on oxide semiconductor fine particles on a substrate so as to face it, and a solution containing a redox electrolyte is filled therebetween. Can be obtained.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

[Example]

Example 1 Synthesis of Dye

The ruthenium dyes D5 and D6 of the present invention were synthesized through the following reaction.

All reactions were run under argon gas conditions and all solvents used were distilled with sodium. 1H, 13C, and 31P NMR were used for the Varian Mercury 300 and the absorbance was used for the Perkin-Elmer Lambda 2S UV-visible spectrophotometer. All starting materials used Aldrich and Strem reagents without purification.

end. 4-bromomethyl-4'-methyl-2,2'-bipyridine

This compound utilizes the synthesis method of the existing literature ( Inorg. Chem. 1991, 30 , 2942). 1 H NMR (CDCl ₃ ): 8.65 (d, JH-H = 4.5 Hz, 1H), 8.54 (d, JH-H = 4.5 Hz, 1H), 8.43 (s, 1H), 8.24 (s, 1H), 7.34 (d, JH-H = 4.5 Hz, 1H), 7.17 (d, JH-H = 4.5 Hz, 1H), 4.47 (s, 2H), 2.45 (s, 3H).

I. 4,4'-bisbromomethyl-2,2'-bipyridine

This compound used the synthesis method of the existing literature ( Inorg. Chem. 1991, 30 , 2942). 1 H NMR (CDCl ₃ ): 8.67 (d, JH-H = 4.5 Hz, 2H), 8.43 (s, 2H), 7.36 (d, JH-H = 4.5 Hz, 2H), 4.48 (s, 4H).

All. 4-Diethylphosphonomethyl-4'-methyl-2,2'-bipyridine (1): ²

A mixed solution of 4-bromomethyl-4'-methyl-2,2'-bipyridine (2 g, 7.60 mmol) and excess triethylphosphite (5 mL, 0.29 mol) was kept at 80 ° C. for 6 hours. Stirred. Thereafter, after cooling to room temperature, excess triethylphosphite was removed under vacuum conditions. The oily residue was separated by pale yellow compound 1 using column chromatography. 1 H NMR (CDCl ₃ ): 8.60 (d, JH-H = 4.5 Hz, 1H), 8.52 (d, JH-H = 4.5 Hz, 1H), 8.32 (s, 1H), 8.22 (s, 1H), 7.31 (d, JH-H = 5.4 Hz, 1H), 7.12 (d, JH-H = 5.4 Hz, 1H), 4.06 (dq, 3 JH-P = 7.2 Hz, 4H), 3.22 (d, 2 JH-P = 21.3 Hz, 2H), 2.43 (s, 3 H), 1.26 (t, 3 JH-H = 7.2 Hz, 6H).

la. 4,4'-bis (diethylphosphonomethyl) -2,2'-bipyridine (2): ²

This compound was synthesized in the same manner as in compound 1 above. 1 H NMR (CDCl ₃ ): 8.60 (d, JH-H = 5.1 Hz, 2H), 8.33 (s, 2H), 7.32 (d, JH-H = 5.1 Hz, 2H), 4.07 (dq, 3 JH-P = 11.4 Hz, 3 JH- H = 7.2 Hz, 8H), 3.23 (d, 2 JH-P = 22.2 Hz, 4H), 1.27 (t, 3 JH-H = 7.2 Hz, 12H).

hemp. 4-bromo-1-diethylphosphonomethyl-benzene.

4-bromobenzyl bromide (10 g, 40 mmol) and triethylphosphite (5 mL, 0.29 mol) were mixed at 80 ° C. for 17 hours. Subsequent synthesis used the same method as above (clear oil). 1 H NMR (CDCl ₃ ): 7.29 (d, JH-H = 8.4 Hz, 2H), 7.04 (d, JH-H = 8.4 Hz, 2H ), 3.89 (dq, 3 JH-P = 12.2 Hz, JH-H = 7.5 Hz, 4H), 2.96 (d, 2 JH-P = 21.3 Hz, 2H), 1.14 (t, 3 JH-H = 7.5 Hz , 6H); 31 P NMR (CDCl 3): 19.99.

bar. 4-bromo- [N, N- (dibutylamino) -styryl] benzene

4-Bromo-1-diethylphosphonomethyl-benzene (7.47 g, 24.30 mmol) and para-dibutylaminobenzaldehyde (4.73 g, 20.3 mmol) were dissolved in THF solution followed by sodium hydride (63.2 w / w oil, 0.92 g, 24.3 mmol) was added. The solution was refluxed for 3 hours to lower the temperature to room temperature, and then the solvent was removed under vacuum conditions. The residue remaining after drying was separated by column chromatography. (silica gel, CH ₂ Cl ₂ / hexane 1: 5, Rf : 0.6) 1 H NMR (CDCl ₃ ): 7.44 (d, JH-H = 7.8 Hz, 2H), 7.38 (d, JH-H = 7.8 Hz, 2H), 7.33 (d, JH-H = 7.4 Hz, 2H), 7.22 (d, JH-H = 7.4 Hz, 2H), 7.02 (d, Jvinyl-HH = 16.2 Hz, 1H), 6.81 (d, Jvinyl-HH = 16.2 Hz, 1H), 3.31 (t, 4H), 1.58 (m, 4H), 1.37 (m, 4H), 0.98 (t, 6H); 13C {1H} NMR (CDCl ₃ ): 148.1, 137.5, 131.7, 129.8, 128.0, 127.5, 124.1, 122.3, 120.0, 111.7, 50.9, 29.6, 20.5, 14.2. Anal. Calcd. for C ₂₂ H ₂₈ BrN: C, 63.39; H, 7.30. Found: C, 63.20; H, 7. 26.

four. [N, N- (dibutylamino) -styryl] benzaldehyde (3): ³

4-Bromo- [N, N- (dibutylamino) -styryl] benzene (5 g, 12.94 mmol) was dissolved in diethyl as a solvent and 1.6 M n -butyllithium (8.9 mL, 14.23 mmol) was added slowly dropwise. After stirring at −10 ° C. for about 30 minutes, DMF (0.97 mL, 12.56 mmol) was added dropwise at room temperature, followed by stirring at room temperature for 2 hours. 6 M HCl after that (50 mL) solution was added and purified using a separatory funnel. After separating the organic layer, water was removed using MgSO ₄ and the remaining solvent was dried under vacuum conditions. The material remaining after drying was purified by column chromatography (CH ₂ Cl ₂ / hexane 1: 3, Rf : 0.3). Compound was pale yellow solid 1H NMR (CDCl ₃ ): 9.95 (s, 1H), 7.82 (d, JH-H = 7.6 Hz, 2H), 7.59 (d, JH-H = 7.4 Hz, 2H), 7.40 (d , JH-H = 7.4 Hz, 2H, 7.19 (d, Jvinyl-HH = 16.2 Hz, 1H), 6.89 (d, Jvinyl-HH = 16.2 Hz, 1H), 6.63 (d, JH-H = 7.6 Hz, 2H), 3.30 (t, 4H), 1.59 (m, 4H), 1.37 (m, 4H), 0.97 (t, 6H); 13C {1H} NMR (CDCl ₃ ): 191.8, 148.6, 144.9, 134.4, 132.8, 130.4, 128.5, 126.3, 123.6, 122.0, 111.6, 50.9, 29.6, 20.5, 14.2. Anal. Calcd. for C ₂₃ H ₂₉ NO: C, 82.34; H, 8.71. Found: C, 82.16; H, 8.64.

Ah. 4-dibutylaminostyrylstyrylstyryl-4'-methyl-2,2'-bipyridine (4): ^{2, 3}

To a THF solution (30 mL) in which No. 3 (0.47 g, 1.41 mmol) and No. 2 (0.47 g, 1.41 mmol) were dissolved, potassium t -butoxide (0.16 g, 1.41 mmol) was added dropwise thereto at room temperature for 10 hours. Was stirred. Thereafter, 10 mL of water was added dropwise, only THF was dried in vacuo, extracted with dichloromethane, and recrystallized with dichloromethane / hexane. Gold powder. 1 H NMR (CDCl ₃ ): 8.63 (d, 3 JH-H = 5.1 Hz, pyridine , 1H), 8.58 (d, 3 JH-H = 5.1 Hz, pyridine , 1H), 8.52 (s, pyridine , 1H), 8.27 (s, pyridine , 1H), 7.52 (d, 3 JH-H = 8.7 Hz, 2H), 7.48 (d, 3 JH-H = 8.7 Hz, 2H), 7.44 (d, 3 Jvinyl-HH = 16.2 Hz , 1H), 7.41 (d, 3 JH-H = 5.1 Hz, pyridine , 1H), 7.39 (d, 3 JH-H = 8.4 Hz, 2H), 7.16 (d, 3 JH-H = 5.1 Hz, pyridine , 1H ), 7.11 (d, 3 Jvinyl-HH = 16.2 Hz, 1H), 7.09 (d, 3 Jvinyl-HH = 16.2 Hz, 1H), 6.88 (d, 3 Jvinyl-HH = 16.2 Hz, 1H), 6.63 (d, 3 JH-H = 8.7 Hz, 2H), 3.30 (t, 4H), 2.46 (s, 3H), 1.59 (m, 4H), 1.37 (m, 4H), 0.97 (t, 6H); 13C {1H} NMR (CDCl ₃ ): 156.7, 156.1, 149.6, 149.1, 148.3, 148.1, 146.0, 139.1, 134.5, 133.2, 129.7, 128.1, 127.5, 126.4, 125.3, 124.9, 124.4, 123.0, 122.2, 121.0, 118.3, 111.7, 50.9, 29.6, 21.4, 20.5, 14.2. Anal. Calcd. for C ₃₅ H ₃₉ N 3: C, 83.79; H, 7.84. Found: C, 83.50; H, 7.76.

character. 4,4'-bis (dibutylaminostyrylstyryl) -2,2'-bipyridine (5): ^{2, 3}

Synthesis was carried out in a similar manner to the compound of No. 4 above. 1 H NMR (CDCl ₃ ): 8.67 (d, 3 JH-H = 5.1 Hz, pyridine , 2H), 8.54 (s, pyridine , 2H), 7.53 (d, 3 JH-H = 8.1 Hz, 4H), 7.49 ( d, 3 JH-H = 8.1 Hz, 4H), 7.46 (d, 3 Jvinyl-HH = 16.5 Hz, 2H), 7.42 (d, 3 JH-H = 5.1 Hz, pyridine , 2H), 7.39 (d, 3 JH-H = 7.8 Hz, 4H), 7.12 (d, 3 Jvinyl-HH = 16.5 Hz, 2H), 7.09 (d, 3 Jvinyl-HH = 16.2 Hz, 2H), 6.88 (d, 3 Jvinyl-HH = 16.2 Hz, 2H), 6.63 (d, 3 JH-H = 7.8 Hz, 4H), 3.30 (t, 8H), 1.58 (m, 8H), 1.37 (m, 8H), 0.97 (t, 12H); 13C {1H} NMR (CDCl ₃ ): 156.6, 149.7, 148.1, 146.1, 139.1, 134.5, 133.3, 129.7, 128.1, 127.5, 126.4, 125.3, 124.3, 123.0, 121.1, 118.3, 111.7, 50.9, 29.6, 20.5, 14.2. Anal. Calcd. for C ₅₈ H ₆₆ N ₄ : C, 85.04; H, 8.12. Found: C, 84.90; H, 8.02.

car. D5

Compound No. 4 ligand (0.20 g, 0.40 mmol) and dichloro ( p -cymene) ruthenium (II) dimer (0.12 g, 0.20 mmol) were dissolved in DMF and the solution was stirred at 80 ° C. for 4 hours. . 4,4'-dicarboxylic acid-2,2'-bipyridine (0.097 g, 0.40 mmol) was added dropwise and stirred at 160 ° C. for 4 hours. In this solution, ammonium cyanate (0.91, 11.96 mmol) was added thereto, stirred at 130 ° C. for 4 hours, the solvent was dried under vacuum, water (200 mL) was added, and the compound was precipitated. The precipitate was filtered using filter paper and dried in air. This precipitate was dissolved by dropwise addition of 1.2 mmol of tetrabutylammonium hydroxide dissolved in methanol, and the dissolved solution was separated by column chromatography with methanol using Sephadex LH-20. The separated dye solution was added to a dilute nitric acid solution to obtain a dye precipitate, and then separated by a filter paper. Dark purple powder. 1 H NMR (DMSO): 9.47 (d, JH-H = 8.1 Hz, 1H), 9.09 (d, JH-H = 7.8 Hz, 1H,), 9.05 (s, 1H), 8.93 (s, 1H), 8.88 (s, 1H), 8.75 (s, 1H), 8.63 (d, JH-H = 8.1 Hz, 1H), 8.26 (d, JH-H = 7.8 Hz, 1H), 8.0 to 6.5 (m, 16H), 3.30 (m, 4H), 2.08 (s, 3H), 1.53 (m, 4H), 1.30 (m, 4H), 0.92 (m, 6H). Anal. Calcd. for C ₄₉ H ₄₇ N ₇ O ₄ RuS ₂ : C, 61.10; H, 4.92. Found: C, 60.98; H, 4.87.

Ka. D6

Compound No. 5 ligand (0.135 g, 0.165 mmol) and dichloro ( p -cymene) ruthenium (II) dimer (0.050 g, 0.082 mmol) were dissolved in DMF, and the solution was stirred at 80 ° C. for 4 hours. 4,4'-dicarboxylic acid-2,2'-bipyridine (0.040 g, 0.165 mmol) was added dropwise and stirred at 160 ° C. for 4 hours. In this solution, ammonium cyanate (0.91, 11.96 mmol) was added thereto, stirred at 130 ° C. for 4 hours, the solvent was dried under vacuum, water (200 mL) was added, and the compound was precipitated. The precipitate was filtered using filter paper and dried in air. The precipitate was dissolved by dropwise adding 4.94 mmol of tetrabutylammonium hydroxide dissolved in methanol, and the dissolved solution was separated by column chromatography with methanol using Sephadex LH-20. The separated dye solution was added to a dilute nitric acid solution to obtain a dye precipitate, and then separated by a filter paper. Dark purple powder. 1 H NMR (DMSO): 9.43 (d, JH-H = 8.1 Hz, 1H), 9.15 (d, JH-H = 7.8 Hz, 1H,), 9.00 (s, 1H), 8.86 (s, 1H), 8.55 (s, 1H), 8.35 (s, 1H), 8.1 to 6.5 (m, 30H), 3.29 (m, 8H), 1.51 (m, 8H), 1.29 (m, 8H), 0.92 (m, 12H). Anal. Calcd. for C ₇₂ H ₇₄ N ₈ O ₄ RuS ₂ : C, 67.53; H, 5.82. Found: C, 67.41; H, 5.80.

Example 2 Fabrication of Dye-Sensitized Solar Cell

The solar cell was prepared using a TiO ₂ film made of Dyesol Titania paste (Dyesol Ltd., Australia). At this time, the Dyesol paste was coated on the FTO glass substrate pretreated with titanium (IV) isoprooxide using the doctor blade method. The paste on the FTO was baked at 450 ° C. for 30 minutes to form a 13 μm thick TiO ₂ thin film layer. The calcined thin film layer was supported in a dye solution in which D5 was prepared in Example 1 at a concentration of 0.5 mM with DMF as a solvent at room temperature for 24 hours. The supported dye coating thin film was immersed in DMF solution for 3 hours to remove unbound dye, and then immersed in ethanol solution for 3 days to remove DMF. The dye-coated TiO ₂ thin film was rinsed with ethanol, and then a solar cell was prepared according to a conventional solar cell manufacturing method.

At this time, the redox electrolyte solution used in the solar cell was prepared using 0.05 MI ₂ , 0.1 M LiI, 0.6 M 1,2-dimethyl-3-hexyl imidazolium iodine and 0.5 M 4-tert- using solvent as methoxypropionitrile. What dissolved butylpyridine was used.

Example 3 and Comparative Example 1-5

To prepare a solar cell in the same manner as in Example 2, in place of D5 dye D6, N3 ([Ru- (dcbpyH ₂ ) ₂ (NCS) ₂ ], where dcbpyH is 4,4'-dicarboxy-2, 2'-bipyridine), D13, D14, D15 and D16 was used as a dye to prepare a solar cell.

The photoelectrochemical characteristics, the IPCE index, the absorption spectrum, and the molar extinction coefficient of the manufactured solar cell were measured and shown in FIGS. 1, 2, Table 1, and Table 2, and in Table 1, J _sc (short- The circuit photocurrent density (V _oc ), open circuit voltage (V _oc ), fill factor (FF), and photoelectric conversion efficiency (η) were measured and shown in Table 2.

The photoelectrochemical characteristics of the solar cell were measured using a Keithley M 236 source measuring device, and a 300 W Xe lamp equipped with an AM 1.5 filter (Oriel) was used as the light source, and the electrode size was 0.4 × 0.4 cm ² . The intensity was 1 sun (100 mW / cm ² ). Light intensity was adjusted using a Si solar cell. The IPCE index was measured using PV Measurement's system. Absorption spectra of the dye in the solution and TiO ₂ film were measured using an HP 8453A diode array spectrophotometer.

TABLE 1

dyes J _sc (mA / cm ² ) V _oc (V) FF η (%) N3 9.80 0.63 0.66 4.1 D5 10.8 0.63 0.68 4.6 D6 11.7 0.63 0.66 4.8 D13 3.39 0.58 0.70 1.4 D14 4.43 0.58 0.67 1.7 D15 3.79 0.58 0.66 1.5 D16 2.36 0.54 0.56 0.72

Figure 1 shows the J-V curve and IPCE (%) of the solar cell prepared by supporting the dyes D5, D6 and N3 of the present invention.

As shown in FIG. 1 and Table 1, D5 and D6 of the present invention can be seen that the curve is higher over the entire wavelength than N3, the light energy conversion efficiency is 4.6% and 4.8%, respectively, higher than 4.3 of N3 Able to know. Therefore, it was confirmed that the ruthenium-based dye of the present invention can produce a solar cell having a remarkably improved efficiency compared to the N3 dye widely used in the conventional solar cell.

TABLE 2

dyes λ _max (nm) (ε _max (10 ⁴ M ^-1 cm ^-1 )) N3 385 (1.36), 533 (1.33) D5 441 (4.03), 527 (2.60) D6 449 (7.85), 539 (3.43) D13 453 (1.61) D14 463 (1.99), 532 (1.76) D15 452 (2.16) D16 471 (4.54), 555 (2.67)

In addition, (a), (b) and (c) of FIG. 2 show a thickness of 7 μm of TiO coated with D5, D6 and N3 at a concentration of 0.5 nm in a DMF solution at 5.0 × 10 ⁻⁶ M concentration and a DMF solution, respectively. ₂ film, and the absorbance spectrum after removing the dye in a 10 mM KOH aqueous solution for 3 days was measured, and the film D5 and D5 in Figure 2a (solution spectra) and 2b (film spectra) and Table 2 It can be seen that N3 was adsorbed on the film in an almost equivalent amount, and D6 confirmed that about 73% of the mole was adsorbed on the film compared to N3. In addition, FIG. 2B and FIG. 2C confirmed that only 84% and 77% of D5 and D6 were removed, whereas N3 was completely removed from the TiO ₂ surface. As a result, it was confirmed that D5 and D6 of the present invention were strongly adsorbed on the surface of TiO ₂ as compared to N3, thereby significantly improving the durability of the solar cell.

In addition, when the dye was prepared in the same manner as in Example 1 using butyl, which is the R of D5 and D6 of the present invention, as methyl, ethyl, and propyl, the photovoltaic conversion efficiency was comparable to that of D5 and D6. Similar results were also found in the bonding force with the semiconductor fine particles.

The novel ruthenium-based dyes of the present invention exhibit significantly improved photovoltaic conversion efficiency than conventional dyes, enhance bonding with oxide semiconductor fine particles, and improve JSC (short circuit photocurrent density) and molar extinction coefficient to improve solar cell efficiency. It can greatly improve.

Claims (10)

Ruthenium-based dyes represented by Formula 1 below: [Formula 1]

In Formula 1, the a1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group, In addition, X and Y are each independently a compound represented by methyl or the formula (2), at least one of X and Y is a compound represented by the formula (2), [Formula 2]

In Formula 2, the b1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group, and R may be the same or different. Each independently hydrogen or an alkyl group having 1 to 15 carbon atoms. The method of claim 1, The dye is a ruthenium (Ru) dye is one of those represented by the following formula.

Method for producing a ruthenium (Ru) -based dye represented by the formula (1) characterized in that to react the compound of formula 4 or 5 with the compound of formula (3), formula (6) and formula (7): (3) RuCl ₂ ( p -cymene) ₂ [Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7] NH ₄ NCS [Formula 1]

In the above formula, the a1 ring may have one or more substituents, and the substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, or an acyl group, and the b1 ring may have one or more substituents. The substituent may be a halogen atom, an amide group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group or an acyl group, and R may be the same or different, and each independently hydrogen or an alkyl group having 1 to 15 carbon atoms. In addition, X and Y are each independently methyl or a compound represented by the following formula (2), at least one of X and Y is a compound represented by the formula (2). [Formula 2]

The method of claim 3, The dye is a method for producing a ruthenium (Ru) dye, characterized in that prepared by the process of the following scheme: [Scheme]

4 and 5 in the above schemes represent the compounds of the formulas (4) and (5), respectively. A dye-sensitized photoelectric conversion element comprising oxide semiconductor fine particles supported by the dye of claim 1. The method of claim 5, The dye-sensitized photoelectric conversion device is a dye-sensitized photoelectric conversion device characterized in that the dye is carried on the oxide semiconductor fine particles in the presence of the inclusion compound. The method of claim 5, Dye-sensitized photoelectric conversion device, characterized in that the oxide semiconductor fine particles contain titanium dioxide as an essential component. The method of claim 5, Dye-sensitized photoelectric conversion device, characterized in that the oxide semiconductor fine particles have an average particle diameter of 1 to 500 nm. A dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device according to claim 5. 10. The method of claim 9, The dye-sensitized solar cell is a step of coating a titanium oxide paste on a conductive transparent substrate, firing the substrate coated with a paste to form a titanium oxide thin film, the substrate in which the titanium oxide thin film is formed is dissolved Impregnating the mixed solution to form a titanium oxide film electrode on which dye is adsorbed, providing a second glass substrate having a counter electrode formed thereon, and forming a hole through the second glass substrate and the counter electrode. Forming a thermoplastic polymer film between the counter electrode and the dye-adsorbed titanium oxide film electrode, and performing a heat compression process to bond the counter electrode and the titanium oxide film electrode to the counter electrode through the hole. Injecting an electrolyte into the thermoplastic polymer film between the titanium oxide film electrode and the thermoplastic polymer Dye-sensitized solar cell, characterized in that it is manufactured through the step of sealing.

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