KR101504526B1 - Dye compond for dye sensitized sola cell and sola cell comprising it - Google Patents

Abstract

The present invention relates to a novel organic dye for dye-sensitized solar cells and a dye-sensitized solar cell comprising the dye. More particularly, the present invention relates to an organic dye having improved photoelectric conversion efficiency and a dye-sensitized solar cell comprising the organic dye.

Description

TECHNICAL FIELD [0001] The present invention relates to a novel organic dye and a dye-sensitized solar cell comprising the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a novel organic dye compound and a dye-sensitized solar cell comprising the same, and more particularly, to an organic dye compound having improved photoelectric conversion efficiency and a dye-sensitized solar cell comprising the organic dye compound.

A solar cell is a device that converts light energy into electric energy by using photovoltaic effect. Unlike other energy sources, it is an energy source that is infinite in resources and environmentally friendly. It is a silicon solar cell, a dye sensitized solar cell It is known.

Silicon solar cells are difficult to put into practical use because they are expensive to manufacture, and there are many difficulties in improving efficiency. On the other hand, the dye-sensitized solar cell has a possibility to replace the conventional amorphous silicon solar cell because the manufacturing cost is significantly lower than that of the conventional silicon solar cell. The dye-sensitized solar cell is a mechanism for generating electron-hole pairs by absorbing light energy of a visible light ray. The dye-sensitized solar cell is composed of a photo-electrochemical solar cell comprising a photosensitive dye molecule and a transition metal oxide Battery.

Currently, ruthenium metal dyes are known as practical dyes for dye-sensitized solar cells. These ruthenium dyes are problematic not only in terms of expensive production cost, low absorption coefficient, but also in environmental friendliness. Recently, researches on the development of organic dyes which do not use metals have been focused on to solve these problems.

In general, organic dyes that do not use metal complexes are synthesized with a structure in which an electron donor and an electron acceptor are connected by a π-bond. At this time, aromatic amine derivatives are used as the electron donor, 2-cyanoacrylic acid is the most used as the electron acceptor, thiophene or phenyl group is used as the? -Conjugate and long or short wavelength The spectrum can be adjusted.

In general, organic dyes have much room for improvement due to low light conversion efficiency, chemical instability, lack of adsorption with metal oxides, etc., compared with ruthenium metal dyes. Therefore, it is necessary to develop cheap organic dyes which can replace ruthenium metal dyes.

Accordingly, in order to solve the problems of the prior art, the present invention provides a method for preventing an open-circuit voltage drop by controlling a substituent for preventing recombination with an electrolyte in a molecule and an electron donor for increasing an electron- And to provide a dye-sensitized solar cell comprising the compound for organic dyes having improved photoelectric conversion efficiency.

According to an aspect of the present invention, there is provided an organic dye for a dye-sensitized solar cell,

[Chemical Formula 1]

In another aspect, the present invention provides a dye-sensitized solar cell comprising a first electrode, a second electrode, and a dye layer formed between the first electrode and the second electrode, wherein the dye layer comprises the dye of the formula 1 < / RTI >

According to the present invention, by introducing a substituent for preventing recombination with the electrolyte in the molecule and an electron donor for increasing the electron donating level, it is possible to prevent the decrease in the open-circuit voltage and to maximize the photoelectric conversion efficiency .

1 is a diagram illustrating a schematic structure of a dye-sensitized solar cell.
2 is a graph showing a light absorption spectrum of an organic dye according to an embodiment of the present invention.
3 is a graph showing current-voltage characteristics of a dye-sensitized solar cell including an organic dye according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate a person skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The term " halo "or" halogen "as used herein, on the other hand, includes fluorine, chlorine, bromine, and iodine unless otherwise specified.

The term "alkyl" or "alkyl group ", as used herein, unless otherwise specified, has from 1 to 60 carbon atoms, but is not limited thereto.

The term "alkenyl" or "alkynyl ", as used herein, unless otherwise indicated, each have a double bond or triple bond of from 2 to 60 carbon atoms,

The term "cycloalkyl" as used herein, unless otherwise specified, means alkyl which forms a ring having from 3 to 60 carbon atoms, but is not limited thereto.

The term "alkoxy group" as used in the present invention has, unless otherwise stated, 1 to 60 carbon atoms, but is not limited thereto.

The terms "aryl group" and "arylene group ", as used herein, unless otherwise specified, each have 6 to 60 carbon atoms, but are not limited thereto.

In the present invention, an aryl group or an arylene group means an aromatic group having a single ring or a heterocyclic ring, and the neighboring substituent includes an aromatic ring formed by bonding or participating in the reaction. For example, the aryl group may be a phenyl group, a biphenyl group, a fluorene group, or a spirobifluorene group.

The term "heteroalkyl ", as used herein, unless otherwise indicated, means an alkyl comprising one or more heteroatoms. The term "heteroaryl group" or "heteroarylene group" as used in the present invention means an aryl or arylene group having 3 to 60 carbon atoms each containing at least one heteroatom, But includes a single ring as well as a heterocyclic ring and may be formed by bonding adjacent groups.

The term " heterocycloalkyl ", "heterocyclic group ", as used herein, unless otherwise indicated, includes one or more heteroatoms, has from 2 to 60 carbon atoms, , And neighboring groups may be combined with each other. Furthermore, the "heterocyclic group" may mean an alicyclic group and / or an aromatic group including a hetero atom.

As used herein, the term "heteroatom " refers to N, O, S, P and Si, unless otherwise indicated.

Unless otherwise stated, the term "aliphatic" as used herein means an aliphatic hydrocarbon having 1 to 60 carbon atoms and an "aliphatic ring" means an aliphatic hydrocarbon ring having 3 to 60 carbon atoms.

Unless otherwise indicated, the term "saturated or unsaturated ring" as used herein refers to a saturated or unsaturated aliphatic ring or an aromatic ring or hetero ring having 6 to 60 carbon atoms.

Other hetero-compounds or hetero-radicals other than the above-mentioned hetero-compounds include, but are not limited to, one or more heteroatoms.

Unless otherwise expressly stated, the term "substituted or unsubstituted ", as used herein, refers to a group selected from the group consisting of deuterium, halogen, amino, nitrile, nitro, C1- , A C1 to C20 alkylamine group, a C1 to C20 alkylthiophene group, a C6 to C20 arylthiophene group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C3 to C20 cycloalkyl group, At least one substituent selected from the group consisting of an aryl group of C60 to C20, a C6 to C20 aryl group substituted by deuterium, an arylalkenyl group of C8 to C20, a silane group, a boron group, a germanium group, and a C5 to C20 heterocyclic group , And it is not limited to these substituents.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary diagram showing a schematic structure of a dye-sensitized solar cell. FIG. In general, a dye-sensitized solar cell 100 includes a transparent substrate 110, a transparent electrode 120, nanoparticles 130, a dye 140, an electrolyte 150, and a counter electrode 160.

That is, a dye-sensitized solar cell is composed of nanoparticles (generally, titanium oxide is used) adsorbing a dye that generates light by receiving electrons, an electrolyte, and a positive electrode acting as an anode.

At this time, the dye (140) is a material directly participating in photoelectron generation. It is advantageous that the absorption occurs over the entire visible light region and the light absorption coefficient is large. The thickness of the dye polymer coating layer is well known to be monomolecular, and when molecules of two or more layers are accumulated, the efficiency is deteriorated due to interference with the transfer of electrons.

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 by the following examples.

Organic dyes according to one aspect of the present invention include:

In the above formulas,

X is a single bond, sulfur (S) or oxygen (O), n is 0 or 1,

R is a C ₁ to C ₂₀ alkyl group,

L ₁ and L ₃ are each independently a C ₆ to C ₆₀ arylene group; A fluorenylene group; A heterocyclic group of C ₂ ~ C _60; And C ₃ ~ C ₆₀ of the ring with C ₃ ~ C ₆₀ alicyclic fused fused ring; is selected from the group consisting of wherein aryl group, a fluorenyl group, a heterocyclic group and a fused ring are each halogen, alkyl group of the silane group, a cyano group, a nitro group, an aryl group or an amine group substituted with heterocyclic, C ₁ ~ C ₂₀ coming of the alkylthio, C ₁ ~ C ₂₀ alkoxy group, C ₁ ~ C ₂₀ of, C ₂ ~ An alkenyl group of C ₂₀ , a C ₆ to C ₂₀ aryl group, a C ₆ to C ₂₀ aryl group substituted by deuterium, a C ₂ to C ₂₀ heterocyclic group, a C ₃ to C ₂₀ cycloalkyl group, C ₇ -C ₂₀ An arylalkyl group and an arylalkenyl group having from ₈ to ₂₀ carbon atoms.

Ar is a C ₂ ~ C ₃₀ substituent comprising a hydrogen bonding potential alkenyl; or

, Wherein R < ₁ > and R < ₂ > may be bonded to each other to form a ring, and may include a substituent capable of hydrogen bonding.

R is a C ₁ to C ₂₀ alkyl group, and L ₂ is a C ₁ to C ₂₀ alkyl group.

The alkenyl group of Ar, the alkyl group of R and the alkyl group of L ₂ may be substituted with at least one substituent selected from the group consisting of a hydroxyl group, a halogen atom, a silane group, a boron group, a cyano group, a C ₁ to C ₂₀ alkoxyl group, a C ₁ to C ₂₀ alkyl group A C ₂ to C ₂₀ alkenyl group, a C ₆ to C ₂₀ aryl group, a C ₆ to C ₂₀ aryl group substituted with deuterium, a C ₂ to C ₂₀ heterocyclic group, a C ₃ to C ₂₀ A cycloalkyl group of C ₇ to C ₂₀ An arylalkyl group and an arylalkenyl group having from ₈ to ₂₀ carbon atoms.

The above formula (1) may be represented by the following formulas. For example, when n = 0 in the general formula (1), n is equal to 1, and when n = 1 and X = S, n = 1 and X is a single bond, It can be displayed together.

[Chemical Formula 2] < EMI ID =

[Chemical Formula 4]

[Formula 1-1] Formula 1-1 '

[Formula 2-1] [Formula 3-1]

[Formula 4-1] [Formula 5-1]

In the above formula, R, X, n, Ar, L ₁ , L ₂ and L ₃ are the same as defined in the above formula (1).

In the above formula (1), L ₁ and L ₃ may be one of the following compounds.

In the formula, R ₃ is a C ₁ -C ₂₀ alkyl group, m is an integer of 1 to 3, and P is an integer of 0 to 10.

The Ar contains a carboxylic acid group (-COOH), and may be represented by one of the following compounds.

On the other hand, the formula (1) may be one of the following compounds.

&Lt; Formula 6 > < EMI ID =

In another aspect, the present invention provides a dye-sensitized solar cell comprising a first electrode, a second electrode, and a dye layer formed between the first electrode and the second electrode, wherein the dye layer comprises the dye of the formula 1 &lt; / RTI &gt;

Synthetic example

Hereinafter, the synthesis example of the compound of formula (1) of the present invention will be described. The following synthesis examples are merely illustrative, and can be prepared by various methods other than the following methods.

Product  Synthesis method

The compounds according to the present invention can be synthesized by way of illustrative examples. Hereinafter, the synthesis method will be described by taking the compound corresponding to the general formula (7) as an example.

(1) 10- (4- hexyl - phenyl ) -10H- phenothiazine  synthesis

Phenanthrene (3.29 g, 13.75 mmol), 1-bromo-4-hexylbenzene (3 g, 16.5 mmol) and sodium tertbutoxide (1.04 g, 5.5 mmol) are thoroughly dissolved in 100 mL of toluene. (8g, 20.63mmol) and Pd ₂ (dba) ₃ (0.5g, 0.55mmol) were added to the reaction mixture. The reaction mixture was sufficiently dissolved at room temperature under nitrogen atmosphere and then stirred at 120 ° C under reflux. When the reaction is complete, work-up is carried out with a 1: 1 mixture of water and CHCl ₃ . The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removal of the solvent, a pale yellow solid product (2.2 g, 48%) was obtained through recrystallization several times with methanol. The chemical properties of the obtained compound are as follows.

_{¹H NMR (300 MHz, CDCl 3} ): δ7.407.26 (m, 4H), 7.016.83 (m, 6H), 6.19 (m, 2H) 2.732.68 (t, J = 7.8Hz, 2H), 1.711. 65 (t, J = 6.3 Hz, 2H), 1.361.26 (m, 4H), 0.930.83 (m, 5H).

1-iodobenzene is a compound corresponding to L ₃ in the formula (1), and since the above reaction scheme is a Buchwald-Hartwig cross coupling reaction, L ₃ -X (wherein X is a halogen compound and L ₃ Is the functional group defined in formula (1)), L ₃ may be phenylene as well as other arylene, heteroarylene, fused ring, etc.

(2) 3,7- dibromo -10- (4- hexyl - phenyl ) -10H- phenothiazine Synthesis of

<Reaction Scheme 2>

After dissolving 10-phenyl-10H-phenothiazine (1.5 g, 5.45 mmol) obtained in the above synthesis in 10 mL of acetic acid, bromine water (1.91 g, 12 mmol) was slowly dropped at 0 ° C. and stirred for 12 hours. When the reaction is complete, titrate with saturated sodium hydroxide in water. After the titration is complete, work-up is carried out with a 1: 1 mixture of water and chloroform. The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removal of the solvent, red solid product (1.5 g, 63.6%) was obtained through several recrystallization steps using methanol and dichloromethane. The chemical properties of the obtained compound are as follows.

¹H NMR (300 MHz, DMSO- d 6): δ7.50-7.48 (d, J = 7.8Hz, 2H), 7.33-7.27 (m, 4H), 7.11-7.07 (m, 2H), 5.99-5.97 ( d, J = 8.7 Hz, 2H), 2.71-2.66 (t, J = 7.8 Hz, 2H), 1.64 (m, 2H), 1.32 (m, 6H), 0.88 (m, 3H).

(3) 3- bromo -7- (2,3- dihydro - thieno [3,4, b] [1,4] dioxin-5- yl ) -10- (4-hexyl-phenyl) -10H-phenothiazine Synthesis of

<Reaction Scheme 3>

A mixture of 3,7-dibromo-10- (4-hexyl-phenyl) -10H-phenothiazine (0.95 g, 2.1 mmol) and tributyl- (2,3- dihydro- (0.1 g, 0.13 mmol) and PdCl ₂ (PPh ₃ ) ₂ (0.1 g, 2.3 mmol) and dibromo-10- (4-hexyl- mmol) are dissolved in 50 mL of dried THF and stirred at 70 DEG C for 24 hours while refluxing. When the reaction is complete, work-up is carried out with a 1: 1 mixture of water and CHCl ₃ . The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removing the solvent, yellow solid product (0.75 g, 81.5%) was obtained by silicagel column chromatography (CHCl ₃ : hexane, 1: 3). The chemical properties of the obtained compound are as follows.

¹H NMR (300 MHz, DMSO- d 6): δ7.54-7.51 (d, J = 8.1Hz, 4H), 7.49-7.47 (d, J = 5.1Hz, 4H), 7.40-7.32 (m, 2H) (M, 4H), 1.36 (m, 4H), 0.94-0.89 (m, 3H).

The above reaction scheme proceeds with the stille reaction as described below,

Since R of Sn corresponds to L ₁ of the present invention, Tributyl- (2,3-dihydrothieno [3,4-3,7-dibromo-10- (4-hexyl-phenyl) , 4] dioxin-5-yl) -stannane was reacted with the Sn compound substituted with L ₁ described in Reaction Scheme 1, the same reaction mechanism The reaction will proceed.

(4) 3- (2- ethylhexyl ) -10- (4- hexylphenyl ) -7- (2,3- dihydrothieno [3,4-b] [1,4] dioxin-7-yl) -10H-phenothiazine

<Reaction Scheme 4>

The 3-bromo-7- (2,3-dihydrothieno [3,4, b] [1,4] dioxin-5-yl) -10- (4-hexyl- (0.72 g, 1.6 mmol) was dissolved in 15 mL of THF, and a (2-ethylhexyl) magnesium bromide solution (0.14 g, 1.7 mmol) was slowly added dropwise thereto and stirred under reflux for 8 hours. When the reaction is complete, work-up is carried out with a 1: 1 mixture of water and CHCl ₃ . The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. The solvent was removed and the orange solid product (0.24 g, 75%) was obtained by silicagel column chromatography (Ethyl acetate: hexane, 1: 9) The chemical properties of the obtained compound are as follows.

¹H NMR (300 MHz, DMSO- d 6): δ7.54-7.51 (d, J = 8.1Hz, 4H), 7.49-7.47 (d, J = 5.1Hz, 4H), 7.40-7.32 (m, 2H) (M, 3H), 1.69-1.67 (m, 6H), 1.36 (m, 12H), 0.94-0.89 (m, 9H).

This reaction is a kind of Grignard reaction.

(5) 3- (5- bromo -2,3- dihydrothieno [3,4-b] [1,4] dioxin-7- yl ) -7- (2-ethylhexyl) -10- (4-hexylphenyl) -10H-phenothiazine

<Reaction Scheme 5>

(2-ethylhexyl) -10- (4-hexylphenyl) -7- (2,3-dihydrothieno [3,4-b] [1,4] dioxin-7-yl) -10H-phenothiazine (1.5 g, 5.45 mmol) was dissolved in 10 mL of acetic acid, and then bromine water (0.8 g, 5.5 mmol) was slowly added dropwise at 0 ° C., followed by stirring for 12 hours. When the reaction is complete, titrate with saturated sodium hydroxide in water. After the titration is complete, work-up is carried out with a 1: 1 mixture of water and chloroform. The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removal of the solvent, red solid product (1.5 g, 63.6%) was obtained through several recrystallization steps using methanol and dichloromethane. The chemical properties of the obtained compound are as follows.

¹H NMR (300 MHz, DMSO- d 6): δ7.54-7.51 (d, J = 8.1Hz, 4H), 7.49-7.47 (d, J = 5.1Hz, 4H), 7.40-7.32 (m, 2H) , 4.36-4.30 (m, 4H), 2.76-2.71 (m, 3H), 1.69-1.67 (m, 6H), 1.36 (m, 12H), 0.94-0.89 (m, 9H).

(6) 3- (2- ethylhexyl ) -10- (4- hexylphenyl ) -7- (2,3- dihydro -5- ( thieno [3,2-b] thiophen-2-yl) thieno [3,4-b] [1,4] dioxin-7-yl) -10H-phenothiazine

<Reaction Scheme 6>

The resulting 7-bromo-2,3-dihydrothieno [3,4, b] [1,4] dioxin-5-yl) -7- (1-ethyl- thieno [3,2-b] thiophen-2-yl-stannane (1.7 g, 2.3 mmol) and PdCl ₂ (PPh ₃ ) ₂ (0.1 g, , 0.13 mmol) were dissolved in 50 mL of dried THF and stirred at 70 DEG C for 24 hours while refluxing. When the reaction is complete, work-up is carried out with a 1: 1 mixture of water and CHCl ₃ . The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removing the solvent, yellow solid product (0.75 g, 81.5%) was obtained by silicagel column chromatography (CHCl ₃ : hexane, 1: 3). The chemical properties of the obtained compound are as follows.

¹H NMR (300 MHz, DMSO- d 6): δ7.54-7.51 (d, J = 8.1Hz, 5H), 7.49-7.47 (d, J = 5.1Hz, 5H), 7.40-7.32 (m, 3H) , 4.36-4.30 (m, 4H), 2.76-2.71 (m, 3H), 1.69-1.67 (m, 6H), 1.36 (m, 12H), 0.94-0.89 (m, 9H).

The above reaction scheme is based on the Stille reaction as described below,

In the present invention, L ₂ substituted with Sn may be substituted with a halogen site of R'-X. Therefore, L ₂ in the formula 1 may be used instead of Tributyl-thieno [3,2-b] thiophen- Is reacted with the substituted Sn compound, the reaction will proceed by the same reaction mechanism.

(7) 5- (5- (3- (2-ethylhexyl) -10- (4-hexylphenyl) -10H-phenothiazin-7-yl) dihydrothieno [3,4-b] [1,4] dioxin-7- yl ) thieno [3,2-b] thiophene -2-carbaldehyde

<Reaction Scheme 7>

(2-ethylhexyl) -10- (4-hexylphenyl) -7- (2,3-dihydro-5- (thieno [3,2- b] thiophen- Dioxin-7-yl) -10H-phenothiazine (0.72 g, 1.6 mmol) was dissolved in 15 mL of 1,2-dichloroethane and then dimethylformamide (0.3 g, 4.09 mmol) Phosphorus oxychloride (0.62 g, 4.09 mmol) was slowly added dropwise at 0 占 폚 and refluxed and stirred for 8 hours. When the reaction is complete, work-up is carried out with a 1: 1 mixture of water and chloroform. The work-up organic layer is separated by extraction and the solvent is removed under reduced pressure. After removal of the solvent, column chromatography (ethyl acetate: hexane, 1: 3) was used to obtain an orange solid product (0.5 g, 63.2%). The chemical properties of the obtained compound are as follows.

_{^{1 H NMR (300MHz, CDCl 3}} ): δ9.85 (s, 1H), δ 7.54-7.51 (d, J = 8.1 Hz, 4H), 7.49-7.47 (d, J = 5.1 Hz, 5H), 7.40- 7.32 (m, 3H), 4.36-4.30 (m, 4H), 2.76-2.71 (m, 3H), 1.69-1.67 (m, 6H), 1.36 (m, 12H), 0.94-0.89 (m, 9H).

The reaction is carried out by the vilsmeier-Haack reaction, and COH is formed by the following mechanism, and the reaction can be carried out for any L ₁ described in the reaction scheme 1.

Product  (Compound 7) Synthesis

<Reaction Scheme 8>

The obtained 5- (5- (3- (2-ethylhexyl) -10- (4-hexylphenyl) -10H-phenothiazin-7-yl) -2,3- dihydrothieno [3,4- b] 4-dioxin-7-yl) thieno [3,2-b] thiophene-2-carbaldehyde (0.4 g, 0.807 mmol), 2-cyanoacrylic acid (0.34 g, 3.99 mmol) and piperidine were dissolved in acetonitrile Lt; / RTI &gt; After completion of the reaction, the solid produced in the reactor was filtered to obtain a dark red solid product (0.45 g, 88.5%). The chemical properties of the obtained compound are as follows.

^{1 H NMR (300MHz, DMSO)} : δ 8.41 (s, 1H), 7.54-7.51 (d, J = 8.1 Hz, 4H), 7.49-7.47 (d, J = 5.1 Hz, 5H), 7.40-7.32 (m , 3H), 4.36-4.30 (m, 4H), 2.76-2.71 (m, 3H), 1.69-1.67 (m, 6H), 1.36 (m, 12H), 0.94-0.89 (m, 9H).

The reaction is a reaction proceeded by the Knoevenagel reaction and proceeds by the following mechanism. Therefore, even if the functional group defined in the formula (1) is bonded in addition to Ar described in the reaction formula (8), it will not affect the progress of the reaction.

[ Example  1] Preparation of dye-sensitized solar cell

A conductive glass substrate (FTO: TEC 8, Pilkington, 8 Ω cm 2, Thickness of 2.3 mm) was washed with ethanol using ultrasonic waves. A commercially available TiO ₂ paste (20 nm, solarnonix) was prepared and coated with a prepared TiO 2 paste on a glass substrate previously cleaned with a doctor blade and baked at 500 ° C for 30 minutes. The thickness of the fired TiO ₂ paste layer was measured by Alpha-step IQ surface profiler (KLA Tencor).

In order to use another TiO ₂ paste as a scattering layer, the calcined layer was re-coated with TiO ₂ particles having a size of 250 nm and then calcined at 500 ° C for 30 minutes. The prepared TiO ₂ film was immersed in 0.04 M TiCl ₄ aqueous solution at 70 ° C for 30 minutes.

For the dye adsorption, the annealed TiO ₂ electrode was immersed in a dye solution of formula (7) according to the present invention at 50 ° C for 3 hours at 0.3 mM. A Pt counter electrode was prepared by thermally reducing the thin film formed from a 0.7 mM H ₂ PtCl ₆ solution dissolved in 2-propanol at 400 ° C for 20 minutes.

The dye-adsorbed TiO ₂ electrode and the Pt counter electrode were assembled using 60 μm-thick Surlyn (Dupont 1702) as a binder. A liquid electrolyte was introduced through the perforation holes on the opposite electrode. Electrolyte was prepared by dissolving 3-propyl-1-methyl-imidazolium iodide (PMII, 0.7M), lithium iodide (LiI, 0.2M), iodine dissolved in acetonitrile / valeronitrile (85:15) (I ₂ , 0.05M) and t-butylpyridine (TBP, 0.5M).

[Comparative Example 1]

The dye-sensitized solar cell was prepared in the same manner as in Example 1, except that the following Comparative Compound 1 was used as a dye.

&Lt; Comparative Compound 1 > N719

Table 1 shows the measurement results of the device characteristics of the dye-sensitized solar cell fabricated as described above, and the electric characteristic measurement condition using the solar simulator used for the measurement is AM 1.5 (1 sun, 100 mW / cm ² ).

Dye Voc  (V) Jsc  ( mAcm ^-2 ) FF  (%) 侶 (%) Example 1 0.676 19.75 64.47 8.32 Comparative Example 1 0.739 17.72 69.47 9.10

In Table 1, Jsc is short-circuit photocurrent density, Voc is opencircuit photovoltage, ff is a fill factor, and? Indicates the total photoconversion efficiency. At this time, the performance of the dye-sensitized solar cell was measured with a working area of 0.24 cm ² .

As can be seen from Table 1, when the organic compound (Compound 7) according to the embodiment of the present invention was used, it was confirmed that an excellent photoelectric conversion efficiency close to the case of using a ruthenium-based dye could be obtained. This can be confirmed also in FIG. 2 and FIG.

FIG. 2 is a graph showing a light absorption spectrum of a dye containing a dye according to an embodiment of the present invention, and FIG. 3 is a graph showing a current-voltage characteristic of a dye- Fig.

Referring to FIG. 2, it can be seen that by adding an electron donor, the absorption wavelength of a shorter wavelength is increased than that of Comparative Example 1 (N719), and the amount of short-circuit current is increased by the electron flow direction control.

Referring to FIG. 3, photoelectric conversion efficiency similar to that of Comparative Example 1 is shown, and particularly, the amount of short-circuit current is higher than that of Comparative Example 1. [

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation in the embodiment in which said invention is directed. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

Claims (8)

An organic dye for a dye-sensitized solar cell represented by the following Formula 3:
(3)

In the above formulas,
R and L ₂ are independently of each other an unsubstituted C ₁ -C ₂₀ alkyl group,
L ₃ is an unsubstituted C ₆ to C ₆₀ arylene group; Or an unsubstituted fluorenylene group,
Ar is a C ₂ to C ₃₀ alkenylene group containing a substituent capable of hydrogen bonding, wherein the alkenylene group may be substituted with a cyano group,
L ₁ is

And

, Wherein R ₃ is a C ₁ to C ₂₀ alkyl group, m is an integer of 1 to 3, and p is an integer of 0 to 10. The method according to claim 1,
The organic dye for a dye-sensitized solar cell according to claim 1,
[Formula 3-1]

In the above formulas, Ar, L ₁ and L ₂ are the same as defined in claim 1. The method according to claim 1,
Wherein L &lt; ₃ &gt; is selected from the group consisting of organic dyes for dye-

. The method according to claim 1,
Wherein L &lt; _{2 &gt;} is an unsubstituted straight-chain alkyl group or an unsubstituted branched-chain alkyl group. The method according to claim 1,
Wherein Ar comprises a carboxylic acid group (-COOH). 6. The method of claim 5,
Wherein Ar is an organic dye for a dye-sensitized solar cell,

. The method according to claim 1,
An organic dye for a dye-sensitized solar cell characterized by being one of the following compounds:
&Lt; Formula 6 >< EMI ID =

. A dye-sensitized solar cell comprising a first electrode, a second electrode, and a dye layer formed between the first electrode and the second electrode,
The dye-sensitized solar cell of claim 1, wherein the dye layer comprises the organic dye of claim 1.

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