KR20100132787A - Organic solar cell and manufacturing method of the same - Google Patents

Abstract

PURPOSE: An organic solar cell and a manufacturing method of the same are provided to increase power conversion efficiency by allowing a hole transformation layer to be contained in a photovoltaic layer. CONSTITUTION: An organic solar cell includes a first electrode(11), a photovoltaic layer(13), and a second electrode(15) which are successively formed on a transparent substrate. The first and second electrodes are easily formed through sputtering or the vacuum evaporation.

Description

Organic solar cell and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solar cell and a method of manufacturing the same, and more particularly, a hole transport material that is soluble in an organic solvent in a photoelectric conversion layer in which a donor (p-type organic semiconductor material) and an acceptor (n-type organic semiconductor material) are mixed. The present invention relates to an organic solar cell and a method for manufacturing the same, in which power conversion efficiency is improved by the addition thereof.

Organic solar cells are expected to be future solar cells due to low manufacturing costs compared to conventional silicon or compound semiconductor solar cells.

In a pn heterojunction type organic solar cell using a donor (p type organic semiconductor) and an acceptor (n type organic semiconductor), the organic semiconductor absorbs excitons of electron-hole pairs by light absorption. It forms and diffuses to the interface of the pn junction. The excitons are charge-separated into electrons and holes by an electric field at the interface, and the separated electrons and holes are moved to different electrodes to generate electromotive force.

However, the organic solar cell of the above configuration has a problem that the diffusion length of the excitons is in the range of several tens of nm, so that the generation of carriers is not performed outside this distance, so the change efficiency is very low.

In order to improve this, U.S. Patent No. 5,331,183 and Korean Patent Publication No. 2005-0087247 present a bulk heterojunction structure in which a pn junction surface is dispersed in a thin film at a nanometer level, thereby greatly improving efficiency.

Conventional bulk heterojunction solar cells generally have a transparent substrate, a transparent electrode (anode) such as a tin doped indium oxide (ITO) thin film formed on the transparent substrate, an aluminum electrode (cathode), and A photoelectric conversion layer including a donor (p-type organic semiconductor) and an acceptor (n-type organic semiconductor) is provided between the transparent electrode and the aluminum electrode.

A conductive polymer such as poly (3-hexylthiophene) such as P3HT is used as the donor, and a fullerene derivative such as fullerene (C60) or PCBM ([6,6] phenyl-C61-butyric acid methyl ester) is used as an acceptor. Although organic solar cells using fullerene as an acceptor (n-type organic semiconductor) are known to exhibit high power conversion efficiency, however, fullerene's electron transport ability is not known as disclosed in Korean Patent Application Publication No. 2008-0104371. It is known that electrons are excessively transported to limit the total amount of generated current by being better than the hole transporting capacity of the donor material (p-type organic semiconductor).

Accordingly, various high mobility materials have recently been developed in the development of donors (p-type organic semiconductors). As the high mobility material, for example, oligo thiophene or pentacene are typical materials, and mobility of around 1 cm ² / Vs can be obtained. However, since it is applied to an organic solar cell and thiophene or pentacene is a molecule bonded in a straight line, it is easy to aggregate, and it is difficult to uniformly disperse uniformly at the nanometer level, thus making it difficult to improve power conversion efficiency.

Accordingly, an object of the present invention is to solve the above problems, and an object thereof is to provide an organic solar cell in which the hole transporting capacity of the photovoltaic layer of the organic solar cell is improved to maximize power conversion efficiency.

Another object of the present invention is to provide a method of manufacturing the organic solar cell.

In order to achieve the above object, the present invention is an organic solar cell comprising a pair of electrodes having at least one light transmitting and a photoelectric conversion layer disposed between the electrodes, the photoelectric conversion layer is a hole transport melting in an organic solvent It provides an organic solar cell comprising a material.

The photoelectric conversion layer is preferably formed by mixing a donor, an acceptor, and a hole transport material soluble in an organic solvent.

The photoelectric conversion layer may be formed by a wet method of any one of spin coating, spray coating, screen printing, doctor blade, and inkjet printing.

The hole transport material soluble in the organic solvent may be at least one selected from aryl amine compounds represented by the following Chemical Formulas 1 to 3.

[Formula 1]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

[Formula 2]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

(3)

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

It is preferable that the thickness of the photoelectric conversion layer is 80 to 150 nm.

In accordance with another aspect of the present invention, there is provided a photoelectric conversion layer including forming a first electrode on a transparent substrate, and a hole transport material soluble in a donor, an acceptor, and an organic solvent on the first electrode. It provides a method of manufacturing an organic solar cell comprising the step of forming and forming a second electrode on the photoelectric conversion layer.

The organic solar cell according to the present invention can improve the power conversion efficiency by including the hole transport material in the photoelectric conversion layer that can improve the hole transport ability, as well as wet coating can simplify the process. It can work.

The organic solar cell according to the present invention includes a pair of electrodes having at least one light transmitting property and a photoelectric conversion layer including a hole transport material soluble in an organic solvent as disposed between the electrodes. The photoelectric conversion layer is formed by mixing a donor, an acceptor, and a hole transport material soluble in an organic solvent.

Hereinafter, an organic solar cell according to the present invention will be described in more detail with reference to the accompanying drawings, but the accompanying drawings are illustrated to help understanding of the present invention, but the present invention is not limited thereto.

1 is a schematic cross-sectional view of an organic solar cell according to an embodiment of the present invention. As shown in FIG. 1, an organic solar cell according to the present invention includes a transparent substrate 10, a first electrode 11, a photoelectric conversion layer 13, and a second electrode 15 on the transparent substrate 10. This is provided sequentially. The organic solar cell further includes a hole injection layer between the first electrode 11 and the photoelectric conversion layer 13, and an electron injection layer 14 between the photoelectric conversion layer 13 and the second electrode 15. Can be.

The transparent substrate 10 may be applied without limitation to those generally used in the solar cell field. Specifically, the transparent substrate 10 may be preferably a flexible substrate made of glass or plastic such as polyimide, polystyrene (PS), polyester (PES), or polycarbonate (PC).

Generally used in the solar cell field may be applied to the first electrode 11 without limitation. More specifically, the first electrode may include (11) transparent indium tin oxide (ITO), indium zinc oxide (IZO), fluorinated tin oxide (FTO), tin oxide, zinc oxide, zinc aluminum oxide, and titanium nitride. Conductive polymers such as metal oxide or metal nitride-based or polyaniline, polythiopine, polypyrrole, polyphenylenevinylene, poly (3-methylthiopine), and polyphenylene sulfide may be used. The first electrode 11 may be formed of only one type of the above materials or may be formed of a mixture of a plurality of materials. In addition, the first electrode 11 may have a multilayer structure in which a plurality of layers of the same composition or different compositions are stacked.

As the second electrode 15, those generally used in the solar cell field may be applied without limitation. More specifically, the second electrode 15 may be a metal such as gold, platinum, silver, copper, aluminum, nickel, cobalt, lead, molybdenum, tungsten, tantalum, niobium, or an alloy thereof.

The first electrode 11 and the second electrode 15 can be easily formed by applying a known method such as sputtering or vacuum deposition, and the thickness thereof is preferably 10 to 500 nm.

A hole injection layer 12 may be formed on the first electrode 11 as needed. The hole injection layer 12 may be made of materials generally known in the solar cell art. Although not limited, the hole injection layer 12 may be made of poly (3,4-ethylenedioxythiophene) and poly (styrenesulfonide) (EDOT / PSS) or copper phthalocyanine (CuPc), 4,4 ', 4 "-. Tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), 4,4'4 "-tris ((N- (naphthalen-2-yl) -N-phenylamino) triphenylamine (2-TNATA) It can be formed by forming a material, such as 5nm ~ 100nm thickness, etc. Particularly, PEDOT / PSS can be formed by a wet process, so hole injection in the organic solar cell to form a light conversion layer by a wet process as in the present invention It can be very usefully used as the layer (6).

According to the present invention, an electron injection layer 14 may be formed between the photoelectric conversion layer 13 and the second electrode 15. The electron injection layer 14 may be made of materials generally known in the solar cell art. Although not limited, the electron injection layer 14 may use LiF, and may be easily formed by forming a film by a known method such as sputtering or vacuum deposition to a known thickness.

The organic solar cell according to the present invention includes a photoelectric conversion layer 13 including a hole transport material soluble in an organic solvent between the first electrode 11 and the second electrode 15. The photoelectric conversion layer 13 is formed by mixing a donor, an acceptor, and a hole transport material soluble in an organic solvent.

In order to improve the hole transport capability of the organic solar cell in the photoelectric conversion layer 13, a method of containing a hole transport material or a hole injection material generally known in the art may be considered. Specifically copper phthalocyanine (CuPc), 4,4 ', 4 "-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA) and 4,4'4" -tris ((N- (naphthalene-2- Yl) -N-phenylamino) triphenylamine (2-TNATA), 4,4'-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (NPD), or N, N A hole transport or hole injection material such as' -diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD) is transferred to the photoelectric conversion layer 13 However, the above-described hole transporting materials or hole injection materials are easily aggregated when applied to the photoelectric conversion layer 13, and have difficulty in uniformly dispersing them at the nanometer level. By using the hole transport material soluble in the wet method to be included in the photoelectric conversion layer 13 to be evenly dispersed to maximize the power conversion efficiency.

The wet method may be applied to any one selected from spin coating, spray coating, screen printing, doctor blade, and inkjet printing.

At this time, the thickness of the photoelectric conversion layer 13 is preferably to be 80 ~ 150nm. When the thickness of the photoelectric conversion layer 13 is included in the range it can be obtained an excellent power conversion efficiency.

The hole transport material soluble in the organic solvent is not necessarily limited, but is preferably at least one selected from aryl amine compounds represented by the following Chemical Formulas 1 to 3.

[Formula 1]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

[Formula 2]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

(3)

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.)

The hole transport material soluble in at least one organic solvent selected from the aryl amine compounds represented by Formulas 1 to 3 may, for example, exemplify a compound represented by Formulas 4 to 7. However, it is not necessarily limited thereto.

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

The aryl amine compound represented by Chemical Formulas 1 to 3 may be easily prepared by applying known techniques. For example, the method described in Korean Patent No. 10-0831510 may be used as a reference. However, the present invention does not limit the production method.

The donors and acceptors used in the photoelectric conversion layer 13 may be generally used in the organic solar cell field. However, as the present invention forms the photoelectric conversion layer 13 by the wet method, it is preferable to use the polymer donor and the polymer acceptor so that the donor and the acceptor can be formed by the wet method.

Specific examples of the polymer donor (p-type organic semiconductor material) are poly (3-hexylthiophene-2,5-diyl) (P3HT) represented by the following Chemical Formula 8, and poly [3- ( Potassium-6-hexanoate) thiophene-2,5-diyl], poly (thiophene-2-5-diyl) represented by the following formula (10), poly (3-obutyl tea) represented by the following formula (11) Offen-2,5-diyl) (P3OT), poly (2-methoxy, 5-2'-ethyl-hexyloxy) -p-phenylene (MEH-PPV), Poly (9,9-dioctylfluorenyl-2,7-diyl) represented by 13, poly (9,9-dioctylfluorenyl-2,7-diyl) represented by the following general formula (14), and the like. Can be mentioned. However, the polymer donor compound which can be used according to the present invention is not limited to the illustrated compound.

    [Formula 8] [Formula 9] [Formula 10]

      [Formula 11] [Formula 12]

    [Formula 13] [Formula 14]

Specific examples of the polymer acceptor (n-type organic semiconductor material) exemplifies poly [2,5-dihexyloxy-1,4- (1-cyanovinylene) phenylene] represented by the following general formula (15). Although it may be, the polymer acceptor compound which can be used according to the present invention is not limited to the illustrated compound.

[Formula 15]

As the acceptor, a low molecular acceptor (n-type organic semiconductor material) other than the above-described polymer acceptor is (6,6) -phenyl-C61 butyric acid methyl ester (PCBM) represented by the following formula (16) and the following formula (17). [6,6] -phenyl C71 butyric acid methyl ester (Compound 10) and the like can be used, but the low molecular acceptor compound is not limited to the exemplified compounds.

        [Formula 16] [Formula 17]

Hereinafter, a method of manufacturing the organic solar cell having the above-described structure will be described in detail.

The method of manufacturing an organic solar cell according to the present invention includes forming a first electrode 11 on a transparent substrate 10, and transporting holes dissolved in a donor, an acceptor, and an organic solvent on the first electrode 11. Forming a photoelectric conversion layer 13 including a material and forming a second electrode 15 on the photoelectric conversion layer 13.

Forming the first electrode 11 on the transparent substrate 10 can be easily performed by applying a known technique. The materials of the transparent substrate 10 and the first electrode 11 may be the ones exemplified in the above-described organic solar cell. The first electrode 11 can be easily formed by depositing the material of the first electrode 11 to a thickness of 10 to 500 nm through a known method such as sputtering or vacuum deposition on the transparent substrate 10.

When the formation of the first electrode 11 is completed, a step of forming the photoelectric conversion layer 13 including a donor, an acceptor, and a hole transport material soluble in an organic solvent is performed on the first electrode 11.

In this case, the hole transport material that is soluble in the donor, the acceptor, and the organic solvent may be the one exemplified in the above-described organic solar cell.

The photoelectric conversion layer 13 may be easily formed by wet application of a solution obtained by dissolving a donor, an acceptor, and a hole transport material soluble in an organic solvent. At this time, the wet coating may be applied to any one selected from spin coating, spray coating, screen printing, doctor blade, and inkjet printing. In consideration of power conversion efficiency, the photoelectric conversion layer 13 may be formed to a thickness of 80 to 150 nm.

The organic solvent can be used without limitation so long as it can dissolve the hole transporting material.

In this case, the donor and acceptor used in the photoelectric conversion layer 13 may be mixed in a mixing ratio generally used in the organic solar cell field. Usually, donors and acceptors are used by mixing in a weight ratio of 1: 0.7 to 1.0.

According to the present invention, the hole transport material soluble in the organic solvent is preferably included in the ratio range of 1: 0.001 to 0.05 with respect to the donor. When the hole transporting material soluble in the organic solvent is included within the above range, the hole transporting capacity of the photoelectric conversion layer 13 may be sufficiently improved to maximize the power conversion efficiency.

Since the organic solvent is volatilized and removed after forming the photoelectric conversion layer 13, the content of the organic solvent need not be limited, but considering the workability during wet application, a donor and acceptor, a hole transport material soluble in an organic solvent, and It is preferable to include 90 to 99 parts by weight of 100 parts by weight of the composition for forming the photoelectric conversion layer 13 including an organic solvent.

When the formation of the photoelectric conversion layer 13 is completed, a step of forming the second electrode 15 on the photoelectric conversion layer 13 is performed.

Forming the second electrode 15 on the photoelectric conversion layer 13 can be easily performed by applying a known technique. What is necessary is just to apply the material of the 2nd electrode 15 which was illustrated by the organic solar cell mentioned above. The second electrode 15 can be easily formed by depositing the material of the second electrode 15 to a thickness of 10 to 500 nm through a known method such as sputtering or vacuum deposition.

According to the present invention, the hole injection layer 12 may be formed between the first electrode 11 and the photoelectric conversion layer 13. The hole injection layer 12 forming step can be easily performed by applying a known technique. The material for forming the hole injection layer 12 may be the one exemplified for the organic solar cell described above. The hole injection layer 12 may be formed by various known methods, and in particular, since the application of the photoelectric conversion layer 13 of the present invention is performed by wet, PEDOT / It is preferable to apply | coat and form in thickness of 5 nm-100 nm by the wet method using PSS.

At this time, the wet coating may be applied to any one selected from spin coating, spray coating, screen printing, doctor blade, and inkjet printing.

According to the present invention, the step of forming the electron injection layer 14 may be performed between the photoelectric conversion layer 13 forming step and the second electrode 15 forming step. The electron injection layer 14 may be easily formed by applying a known technique. The material for forming the electron injection layer 14 may be the one described above for the organic solar cell described above. The electron injection layer 14 can be easily formed by forming a film by a known method such as sputtering or vacuum deposition. The film formation thickness can be made into the thickness of 0.5-30 nm which is the thickness generally formed in the field of an organic solar cell.

Hereinafter, the present invention will be described in detail with reference to the following examples, which are presented to aid the understanding of the present invention, but the present invention is not limited thereto.

Synthesis Example 1

As shown in Scheme 1 below, 22 g (0.13 mmole) of fluorene and 100 ml of dry tetrahydrofuran were placed under argon in a 500 ml three-necked flask, and the resulting mixture was cooled to -78 ° C. To the cooled mixture was added dropwise 120 ml of a hexane solution (2.6 M) of n-butyllithium (0.32 mole). After the resulting solution was stirred at the same temperature for 1 hour, a solution prepared with 59 g (0.3 mole) of octyl bromide and 60 ml of tetrahydrofuran was added dropwise at -78 ° C. The temperature of the resulting solution was slowly raised to room temperature and the solution was stirred overnight. After the reaction was completed, the reaction solution was poured into 1 liter of water, extracted with isopropyl ether, washed with saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was distilled off. The residue was purified by silica gel chromatography developing solvent hexane to give 45 g (yield: 88%) of the intermediate compound (b).

In a 1 liter three-necked flask with light blocking, 20 g (0.05 mmol) of the intermediate compound (b) obtained above, 100 ml of chloroform and 0.2 g of FeCl ₂ were added. Then 24 g (0.15 mole) bromine were added dropwise at 0 ° C. The resulting mixture was allowed to react overnight at room temperature. After the reaction was completed, precipitated crystals were separated by filtration, washed with water and ethanol and dried under heat to obtain 15 g (yield: 55%) of the intermediate compound (c) as a target compound.

Scheme 1

Synthesis Example 2

As shown in Scheme 2, 21.93 g (0.04 mmol) of the compound (c) prepared in Synthesis Example 1, 10.00 g (0.02 mmol) of the compound (d) and a catalytic amount of tetrakis (Tri) in a 250 mL three-neck flask under nitrogen atmosphere. Phenylphosphine) palladium was added, and 80 mL of 1,2-dimethoxyethane and 40 mL of 2M sodium carbonate aqueous solution were added thereto, and the mixture was refluxed at 95 ° C. for 18 hours. After completion of the reaction, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and a solution of 15: 1 volume ratio of ethyl acetate and hexane was used as a developing solvent. Separation and purification by chromatography was performed. After the desired product was separated, 9 g (yield: 52%) of compound (e) was obtained by drying under reduced pressure.

Scheme 2

≪ Synthesis Example 3 &

In the 300 ml three-necked flask equipped with a condenser as shown in Scheme 3 below, 3.5 g (0.004 mmol) of the intermediate compound (e) prepared in Synthesis Example 2, 2.57 g (0.008 mmol) of the compound (f), and tris Benzylidene acetone) dipalladium 0.27 g (1.5 mol%), tri-o-tolylphosphine 0.18 g (3 mol%), sodium t-butoxide 1.9 g (20 mmol) and 100 ml of dry toluene were added under argon. Was stirred at 100 ° C. overnight. After the reaction was completed, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and the hexane solution was used as a developing solvent, and then purified by chromatography using silica gel. . After the desired product was separated, 3 g (yield: 67%) of the compound of formula 4 was obtained by drying under reduced pressure.

Scheme 3

≪ Synthesis Example 4 &

As shown in Scheme 4 below, the compound (g) 5.8 g (0.02 mmol), the compound (c) 21.93 (0.04 mmol) prepared in Synthesis Example 1, and a catalytic amount of tetrakis (tri) were added to a 250 mL three-necked flask under a nitrogen atmosphere. Phenylphosphine) palladium was added, and 80 mL of 1,2-dimethoxyethane and 40 mL of 2M-sodium carbonate aqueous solution were added thereto, and the mixture was refluxed at 95 ° C. for 18 hours. After completion of the reaction, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and a solution of 15: 1 volume ratio of ethyl acetate and hexane was used as a developing solvent. Separation and purification by chromatography was performed. The desired compound was separated and dried to obtain 10 g (yield: 70%) of compound (h) through vacuum drying.

Scheme 4

≪ Synthesis Example 5 &

As shown in Scheme 5, 2.85 g (0.004 mmol) of the intermediate compound (h) prepared in Synthesis Example 4 in a 300 ml three-necked flask equipped with a condenser, compound (i) 1.35 g (0.008 mmol), and Tris (D) Benzylidene acetone) dipalladium 0.27 g (1.5 mol%), tri-o-tolylphosphine 0.18 g (3 mol%), sodium t-butoxide 1.9 g (20 mmol) and 100 ml of dry toluene were added under argon. Was stirred at 100 ° C. overnight. After the reaction was completed, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and the hexane solution was used as a developing solvent, and then purified by chromatography using silica gel. . After the desired product was separated, 2.5 g (yield: 78%) of the compound of formula 5 was obtained by drying under reduced pressure.

Scheme 5

≪ Synthesis Example 6 &

In a 250 mL three-necked flask, 10.00 g (0.02 mmol) of compound (d) was prepared under nitrogen atmosphere, 5.48 g (0.04 mmol) of compound (c) prepared in Synthesis Example 1, and a catalytic amount of tetrakis (triphenylphosphine) palladium. 80 mL of 1,2-dimethoxyethane and 40 mL of 2M aqueous sodium carbonate solution were added thereto, and the mixture was refluxed at 95 ° C. for 18 hours. After completion of the reaction, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and a solution of 15: 1 volume ratio of ethyl acetate and hexane was used as a developing solvent. Separation and purification by chromatography was performed. After the desired product was separated, 9 g (yield: 76%) of the compound of formula 6 was obtained by drying under reduced pressure.

Scheme 6

Synthesis Example 7

As shown in Scheme 7 below, in a 250 mL three-necked flask under nitrogen atmosphere, 5.8 g (0.02 mmol) of compound (g), 5.48 g (0.01 mmol) of compound (c) prepared in Synthesis Example 1, and a catalytic amount of tetrakis ( Triphenylphosphine) palladium was added, and 80 mL of 1,2-dimethoxyethane and 40 mL of 2M-sodium carbonate aqueous solution were added thereto, and the mixture was refluxed at 95 ° C. for 18 hours. After completion of the reaction, the reaction temperature was lowered to room temperature, the organic layer was extracted with distilled water and ethyl acetate, dried over magnesium sulfate, the solvent was removed under reduced pressure, and a solution of 15: 1 volume ratio of ethyl acetate and hexane was used as a developing solvent. Separation and purification by chromatography was performed. After the desired product was separated, 7 g (yield: 80%) of the compound of formula 7 was obtained by drying under reduced pressure.

Scheme 7

Example 1 Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

P3HT (Formula 8), PCBM (Formula 16), bisdiphenyl-4-yl- (7- (4-yl-bisdiphenyl-4-yl-amino) -phenyl) -9, on the hole injection layer, A solution obtained by dissolving 9-dioctyl-9H-fulleren-2-yl) -amine (compound of formula 4 prepared in Synthesis Example 3) in toluene at a ratio of 1: 0.8: 0.018 (solid content 3.64%) at 1,000 rpm. The film was spin-coated to a thickness of 100 nm to form a photoelectric conversion layer.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to produce an organic solar cell.

Example 2 Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

P3HT (Formula 8), PCBM (Formula 16), [7- (4-Diphenylamino-phenyl) -9,9-dioctyl-9H-fullen-2-yl] -diphenyl- on the hole injection layer A solution obtained by dissolving an amine (compound of Formula 5 prepared in Synthesis Example 5) in toluene at a ratio of 1: 0.8: 0.018 (solid content 3.64%) was spin-coated at 1,000 rpm to form a film at a thickness of 100 nm to form a photoelectric conversion layer.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to produce an organic solar cell.

Example 3 Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

A solution in which the hole transporting material represented by P3HT (Formula 8), PCBM (Formula 16), and Formula 6 prepared in Synthesis Example 6 was dissolved in toluene in a ratio of 1: 0.8: 0.018 (solid content 3.64%) on the hole injection layer. Was spin-coated at 1,000 rpm to form a film with a thickness of 100 nm to form a photoelectric conversion layer.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to produce an organic solar cell.

Example 4 Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

A solution in which the hole transporting material represented by P3HT (Formula 8), PCBM (Formula 16), and Formula 7 prepared in Synthesis Example 7 was dissolved in toluene in a ratio of 1: 0.8: 0.018 (solid content 3.64%) on the hole injection layer. Was spin-coated at 1,000 rpm to form a film with a thickness of 100 nm to form a photoelectric conversion layer.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to fabricate an organic solar cell device.

Comparative Example 1: Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

P3HT (Formula 8), PCBM (Formula 16), 4,4'-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (NPD) (Formula 18) on the hole injection layer; A substance insoluble in an organic solvent) was added to toluene in a ratio of 1: 0.8: 0.018 (solid content 3.64%) and spin-coated at 1,000 rpm to form a film having a thickness of 100 nm.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to produce an organic solar cell.

[Formula 18]

Comparative Example 2: Fabrication and Evaluation of Organic Solar Cell

ITO was vacuum-deposited on a 25 mm × 25 mm × 1.1 mm size transparent glass substrate to form a first electrode having a thickness of 150 nm, followed by ultrasonic cleaning in isopropyl alcohol for 5 minutes, and UV ozone cleaning for 30 minutes. It was.

The glass substrate with a transparent electrode after washing | cleaning was mounted in the holder of a spin coater, and PEDOT (poly (3, 4- ethylene dioxythiophene)): PSS (poly ( Styrene sulfonide)) was spin-coated at 4500 rpm to form a thickness of 30 nm, and then baked at 150 ° C. for 10 minutes.

On the hole injection layer, a solution obtained by dissolving P3HT (Formula 8) and PCBM (Formula 16) in a ratio of 1: 0.8 (solid content of 3.6%) was spin-coated at 1,000 rpm to form a photoelectric conversion layer by forming a film at 100 nm thickness.

Subsequently, the substrate was mounted on a holder of a vacuum deposition equipment, and a LiF film was formed thereon at a film formation rate of 0.1 s / sec and a film thickness of 1 nm, followed by evaporation of Al to a thickness of 100 nm. The substrate after Al deposition was annealed at 160 ° C. for 10 minutes to produce an organic solar cell.

Experimental Example

The organic solar cells prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated for efficiency in the following manner, and the results are shown in Table 1 below.

-Efficiency evaluation-

Xenon lamp (Oriel, 92199A) was used as a light source, and the solar condition (AM 1.5) of the xenon lamp was a standard solar cell (Furnhofer Institute Solare Engeriessysteme, Certificate No. C-ISE369, Type of material: Mono-). Si KG filter). The photocurrent efficiency (η%) calculated by substituting the photocurrent density (Jsc), the open circuit voltage (Voc), and the fill factor (FF) calculated from the measured photocurrent voltage curves is shown in Table 1 below.

η = (VocJscFF) / (Pinc)

In the above formula, Pinc represents 100 mW / cm ² (1 sun).

Organic solar cell efficiency Solar cell Voc [V] Jsc [mA / cm2] F.F [%] Optical conversion efficiency [%] Example 1 0.6 12.72 42.73 3.29 Example 2 0.6 11.49 47.7 3.33 Example 3 0.6 12.03 48.47 3.54 Example 4 0.6 11.92 44.12 3.13 Comparative Example 1 0.58 10.6 43.85 2.68 Comparative Example 2 0.6 12.44 39.14 2.94

As shown in Table 1, in Examples 1 to 4 including the hole transporting material soluble in the organic solvent according to the present invention, Comparative Example 1 and the hole transporting material including the hole transporting material insoluble in the organic solvent are not included. It can be seen that the light conversion efficiency is significantly improved compared to Comparative Example 2.

1 is a schematic cross-sectional view of an organic solar cell according to an embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

10 transparent substrate 11 first electrode layer

12 hole injection layer 13 photoelectric conversion layer

14 electron injection layer 15 second electrode

Claims (13)

An organic solar cell comprising a pair of electrodes having at least one light transmitting property and a photoelectric conversion layer disposed between the electrodes, The photovoltaic layer is an organic solar cell comprising a hole transport material soluble in an organic solvent. The organic solar cell of claim 1, wherein the photoelectric conversion layer is a mixture of a donor (p-type organic semiconductor material), an acceptor (n-type organic semiconductor material), and a hole transport material soluble in an organic solvent. The organic solar cell of claim 1, wherein the hole transport material soluble in the organic solvent comprises at least one selected from aryl amine compounds represented by the following Chemical Formulas 1 to 3. [Formula 1]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) [Formula 2]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) (3)

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) The organic solar cell of claim 1, wherein the photoelectric conversion layer is formed by any one wet method selected from spin coating, spray coating, screen printing, doctor blade, and inkjet printing. The organic solar cell of claim 1, wherein the photoelectric conversion layer has a thickness of 80 to 150 nm. The organic solar cell of claim 1, further comprising a hole injection layer between the first electrode layer and the photoelectric conversion layer, and an electron injection layer between the photoelectric conversion layer and the second electrode layer. Forming a first electrode on the transparent substrate; Forming a photoelectric conversion layer on the first electrode, the photoelectric conversion layer including a donor, an acceptor, and a hole transport material soluble in an organic solvent; And And forming a second electrode on the photoelectric conversion layer. The method of claim 7, wherein the forming of the photoelectric conversion layer is performed by applying a wet method to a solution including a donor, an acceptor, and a hole transport material soluble in an organic solvent. The method of claim 8, wherein the wet method is any one selected from among spin coating, spray coating, screen printing, doctor blade, and inkjet printing. The method of claim 7, wherein the hole transport material soluble in the organic solvent comprises at least one selected from aryl amine compounds represented by Formulas 1 to 3 below. [Formula 1]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) [Formula 2]

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) (3)

(In the above, R is each independently selected from a linear or nonlinear alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 50 carbon atoms.) The method of claim 7, wherein the thickness of the photoelectric conversion layer is 80 ~ 150nm. The method of claim 7, further comprising forming a hole injection layer on the first electrode between the step of forming the first electrode and the step of forming the photoelectric conversion layer. Way. The method of claim 7, further comprising forming an electron injection layer on the photoelectric conversion layer between the forming of the photoelectric conversion layer and the forming of the second electrode. Way.

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