KR101748676B1

KR101748676B1 - Polymer with Bis-Tolane as an Integrated part of Benzodithiophene donor unit and organic photovoltaic device using the same

Info

Publication number: KR101748676B1
Application number: KR1020150109994A
Authority: KR
Inventors: 진성호
Original assignee: 부산대학교 산학협력단
Priority date: 2015-08-04
Filing date: 2015-08-04
Publication date: 2017-06-19
Also published as: KR20170016643A

Abstract

The present invention relates to a macromolecular compound comprising a benzodithiophene unit and bis-tolyl which partially forms an integrated structure with the benzodithiophene, and an energy conversion device using the same.
Specifically, the present invention discloses a macromolecular compound comprising a benzodithiophene unit and bis-tollan that forms a partially integrated structure with the benzodithiophene, and is represented by the following Formula 1:
[Chemical Formula 1]

(Wherein n is an integer of 5 to 100,
F, Br, Cl, NO ₂ , CN, R ₁ , R ₂ , R _3, R ₄ , R ₅ , R _6, R ₇ , R ₈ , R ₉ and R ₁₀ are each, independently of one another, A C _1-20 linear or branched alkyl group, and a C _1-20 linear or branched alkoxybenzene group,
A is an electron acceptor aromatic compound.)

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer compound having a benzodithiophene unit and bis-toluene which partially forms an integrated structure with the benzodithiophene, and an energy conversion element using the same. photovoltaic device using the same}

The present invention relates to a polymer compound comprising a benzodithiophene unit and bis-tolyl that partially forms an integrated structure with the benzodithiophene, and an energy conversion device using the same. More particularly, the present invention relates to a polymer comprising a phenylethynyl group Which is synthesized by adding bis-toluene to benzene rings of benzodithiophene on both sides.

Solar cells are attracting attention as an endless, renewable and environmentally friendly source of electrical energy. Currently, solar cell uses inorganic materials (silicon crystal type solar cell, which is the most representative raw material). The first generation crystalline solar cell accounts for 90% of the solar power generation market. However, the cost of power generation is five to 20 times higher than coal, oil, and gas. As a result, second-generation technology emerged as an alternative. Silicon (5.2%), CdTe (4.7%) and CIGS (0.5%) account for 10% of the market for the second-generation thin-film solar cell market, but are still insignificant. However, the second-generation solar cell technology also has a problem that the manufacturing process of the device is difficult and the expensive equipment is required, which results in high unit cost. The main reasons for the cost increase are mainly due to the process of providing the semiconductor thin film under vacuum and high temperature. Therefore, an organic polymer solar cell capable of drastically lowering the production cost by a low temperature solution process is considered as a new possibility. Currently, energy materials using organic polymers have a lower photoelectric conversion efficiency (PCE) than inorganic materials, but their importance is increasing due to the advantages of organic materials such as ease of manufacture, mechanical flexibility, ease of molecular design, and price .

However, an organic solar cell using an organic semiconductor such as a conjugated polymer has a maximum photoelectric conversion efficiency lower than that of a conventional solar cell using an inorganic semiconductor, and has not reached practical use yet. There are three main reasons for the low photoelectric conversion efficiency of an organic solar cell using a conventional conjugated polymer. Firstly, the absorption efficiency of sunlight is low. Second, in the case of organic semiconductors, the binding energy of excitons generated by sunlight is large, so that it is difficult to separate electrons and holes. Third, traps for capturing carriers (electrons and holes) are likely to be formed, so that the generated carriers are easily trapped by the traps and the carrier mobility is low. That is, the semiconductor material generally requires high mobility of the carrier of the material. The conjugated polymer has a problem that the mobility of the charge carrier is lower than that of the conventional inorganic crystal semiconductor or amorphous silicon.

For this reason, a means for absorbing a lot of sunlight and for separating generated electrons and holes from the exciton well and a carrier trapping by scattering or trapping of carriers between the amorphous region of the conjugated polymer or the conjugated polymer skeleton, It is a very important key to put organic semiconductor solar cells into practical use.

The photoelectric conversion device based on organic semiconductors known so far can generally be classified into the following device configurations. A Schottky junction for bonding an electron-donating organic material (p-type organic semiconductor) and a metal having a small work function to each other, a hetero-junction type for bonding an electron-accepting organic material (n-type organic semiconductor) . In these devices, only the organic layer near the junction (about the water molecule layer) contributes to the generation of the photocurrent, and thus the photoelectric conversion efficiency is low and the problem is to be improved.

As a method of improving the photoelectric conversion efficiency, there is a bulk heterojunction type in which an electron-accepting organic material and an electron-donating organic material are mixed and the junction surface contributing to photoelectric conversion is increased. Among them, a photoelectric conversion device using a conjugated polymer as an electron donating organic material and a semiconductor polymer having an n-type semiconductor property and a fullerene derivative such as C60 as an electron-accepting organic material has been reported.

Disclosure of the Invention The present invention aims to provide a polymer compound as a novel organic material for a high-efficiency organic thin film solar cell.

It is another object of the present invention to provide an organic polymer thin film solar cell device comprising the polymer compound.

It is another object of the present invention to provide an organic thin film transistor including the polymer compound as an organic semiconductor material.

Another object of the present invention is to provide an organic electroluminescent device including the polymer compound as a light emitting material.

The object of the present invention is to provide a macromolecular compound represented by the following general formula (1), which comprises a benzodithiophene unit and bis-tolane which forms a partially integrated structure with the benzodithiophene.

[Chemical Formula 1]

(Wherein n is an integer of 5 to 100,

F, Br, Cl, NO ₂ , CN, R ₁ , R ₂ , R _3, R ₄ , R ₅ , R _6, R ₇ , R ₈ , R ₉ and R ₁₀ are each, independently of one another, A C _1-20 linear or branched alkyl group, and a C _1-20 linear or branched alkoxybenzene group,

A is an electron acceptor aromatic compound.)

According to another aspect of the present invention, there is provided an organic polymer thin film solar cell device comprising the polymer compound.

According to another aspect of the present invention, there is provided an organic thin film transistor including the polymer compound as an organic semiconductor material.

According to another aspect of the present invention, there is provided an organic electroluminescent device including the polymer compound as a light emitting material.

According to the present invention, by synthesizing a benzodithiophene unit and a polymer compound containing bis-tolane which partially forms an integrated structure with the benzodithiophene, a high-efficiency organic thin film solar cell exhibiting high hole mobility and photoelectric conversion efficiency It is possible to provide a novel polymeric material for the polymer. Therefore, the polymer synthesized in the present invention can be used as a material of the photoactive layer of the organic polymer thin film solar cell device, and the device can not only have a high photoelectric conversion efficiency, but also maintain a high photoelectric conversion efficiency for a long time It is effective.

FIG. 1 is a gel permeation chromatogram (GPC) graph of a polymer compound comprising bis-toluene synthesized according to an embodiment of the present invention.
FIG. 2 is a graph of thermal stability (TGA) for a polymer compound including bis-toluene synthesized according to an embodiment of the present invention.
FIG. 3 shows hole mobility of a device made using a polymer compound including bis-toluene synthesized according to an embodiment of the present invention.
4 is a UV-Vis absorption spectrum of a polymer compound comprising bis-tolylene synthesized according to an embodiment of the present invention, wherein (a) is a spectrum measured in a solution state, (b) Lt; / RTI >
FIG. 5 is a cyclic voltammetry (CV) graph of a polymer compound comprising bis-toluene synthesized according to an embodiment of the present invention.
FIG. 6 is a graph showing current density-voltage ( J - V ) of a device made using a polymer compound including bis-toluene synthesized according to an embodiment of the present invention.
FIG. 7 is a graph showing photoelectric conversion efficiency (PCE) of a device made using a polymer compound including bis-toluene synthesized according to an embodiment of the present invention.
8 is a graph showing the external quantum efficiency (EQE) of a device made using a polymer compound including bis-toluene synthesized according to an embodiment of the present invention.

The present invention relates to a benzodithiophene unit and a macromolecular compound represented by the following general formula (1), which comprises bis-tolane which partially forms an integrated structure with benzodithiophene.

[Chemical Formula 1]

(Wherein n is an integer of 5 to 100,

A is an electron acceptor aromatic compound.)

In the present invention, R ₄ and R ₇ is

.

(Wherein R < ₁₁ > is a _C1-20 linear or branched alkyl group).

Preferably R < ₄ > and R < _{7 &}

.

Further, in the present invention,

A is

,

And

Is a polymer compound.

(Wherein R ₁₂ and R ₁₃ are C _1-20 linear or branched alkyl groups).

Preferably, A is

.

The polymer compound represented by Formula 1 according to the present invention may be represented by the following Formula 2 to Formula 4, but is not limited thereto.

(2)

(3)

[Chemical Formula 4]

(Wherein n is an integer of 5 to 100,

Of _{R 1, R 2, R 3} , R 5, R 6, R 8, R 9 and R ₁₀ are each independently the same or different H, F, Br, Cl, NO 2 together, CN, C _1-20 A linear or branched alkyl group, and a C _1-20 linear or branched alkoxybenzene group,

R ₁₁ is a C _1-20 linear or branched alkyl group,

R ₁₂ and R ₁₃ are C _1-20 linear or branched alkyl groups.)

Preferably, the polymer compound according to the present invention can be represented by the polymer compound of the formulas (5) and (6).

[Chemical Formula 5]

[Chemical Formula 6]

(Wherein n is an integer of 5 to 100).

The polymeric compound represented by Formula 5 may be prepared by reacting poly [4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynylbiphenyl) benzo [1,2- b: 4,5- b'] dithiophene] PBDTBPA (H) -DPP 'hereinafter referred to as " PBDTBPA (H) -DPP " The polymeric compound represented by Formula 6 may be prepared by reacting poly [4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl) benzo [ ] dithiophene] -alt- [2,5-diethylhexl-3,6-bis (5-thiophen-2-yl) pyrrolo [3,4- Quot; -DPP ".

The method of synthesizing the compound represented by the formula (1) of the present invention is characterized in that benzodithiophene is bound to ethynylbiphenyl and a polymer is obtained through coupling with a monomer having various electron accepting ability . May be synthesized using conventional methods known in the art and may be synthesized by the following reaction without any particular limitation.

[Reaction Scheme 1]

Benzo [1,2-b: 4,5-b '] dithiophene] - (2-ethylhexyloxy) Alt - [2,5- Diethylhexyl -3,6-bis (5- Thiophene -2 days) Pirolo [3,4-c] -pyrrole-l, 4- Dion ] [ PBDTBPA (H) - DPP ].

As shown in the above reaction formula, 1,3-dibromobenzene was reacted with trimethylsilylacetylene to obtain ((3-bromophenyl) ethynyl) trimethylsilane (Formula 1) ) Ethynyl) trimethylsilane was reacted with 2- (4- (2-ethylhexyloxy) phenyl) -4,4,5,5-tetramethyl-1,3,2-dioxaboroline to give ( (2 ', 4' - (2-ethylhexyloxy) biphenyl-3-yl) ethynyl) trimethylsilane ) Ethynyl) trimethylsilane was obtained by using 4 - (2-ethylhexyloxy) -3-ethynylbiphenyl [BPA (H)] using potassium hydroxide and methanol. Dibidrobenzo [1,2-b: 4,5-b '] dithiophene-4,8-dione was reacted to give 4,8 (4) - (2-ethylhexyloxy) -3-ethynylbiphenyl) benzo [1,2-b: 4,5- b '] dithiophene , 8-bis (4 '- (2- 2,6- (trimethylthiine) - 3-ethynylbiphenyl) benzo [1,2-b: 4,5-b '] dithiophene was synthesized by using tert-BuLi and trimethyltin chloride. Benzo [1,2-b: 4,5-b '] dithiophene [BDTBPA (H)] was obtained by reacting 4,8-bis (4' Benzyl [1,2-b: 4,5-b (4'-bis (2-ethylhexyloxy) (2H, 5H) -dithiophene and 2,5-bis (2-ethylhexyl) -3,6-di (thiophen- 4 - (2-ethylhexyloxy) -3-ethynylbiphenyl) benzo [1,2-b: 4,5-b '] dithiophene] -aldehyde - [2,5-diethylhexl-3,6-bis (5-thiophen-2-yl) pyrrolo [3,4-c] -pyrrole-1,4-dione] [PBDTBPA (H) -DPP] .

[Reaction Scheme 2]

Poly [4,8-bis (4 '- (2- Ethylhexyloxy ) -3- Ethynyl -2,4- Difluorobiphenyl ) Benzo [ 1,2-b: 4,5-b '] dithiophene ] - Alt - [2,5- Diethylhexyl -3,6- Bis (5- Thiophene Pyrrolo [3,4-c] -pyrrole-1,4-dione] [PBDTBPA (F) -DPP].

As shown in the above reaction scheme, by reacting 2,4-difluorophenylboronic acid with 1-bromo-4- (2-ethylhexyloxy) benzene, 4 '- (2-ethylhexyloxy) 2,4-difluorobiphenyl (Formula 4) was obtained and the 4 '- (2-ethylhexyloxy) -2,4-difluorobiphenyl (Formula 4) and lithium diisopropylamide (Ethylhexyloxy) -2,4-difluoro-3-iodobiphenyl (Formula 5) was obtained using 4'-2 (ethylhexyloxy) -2 (4- (2-ethylhexyloxy) -2,4-difluorobiphenyl-3-yl) ethynyl) trimethylsulfanyl is reacted with 4-difluoro- ((4- (2-ethylhexyloxy) -2,4-difluorobiphenyl-3-yl) ethynyl) trimethylsilane was reacted with potassium hydroxide and methanol 4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl [BP (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl and 4,8-dihydrobenzo [1,2-b (4'- (2-ethylhexyloxy) -3-ethynyl-2,4-difluoro-4,5-b '] dithiophene-4,8- (4 '- (2-ethylhexyloxy) -3, 4-dihydroxybenzo [1,2- b: 4,5- b'] dithiophene 4-difluorobiphenyl) benzo [1,2-b: 4,5-b '] dithiophene was reacted with 2,6- (trimethyltin) -4, Bis [4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl) benzo [1,2- b: 4,5- b'] dithiophene [ BDTBPA (F)] was obtained, the 2,6- (trimethylthyne) -4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluoro Biphenyl) benzo [1,2-b: 4,5-b '] dithiophene and 2,5-bis (2-ethylhexyl) -3,6-di (thiophen- 3,4-c] pyrrole-1,4 (2H, 5H) dion and still coupling reaction, poly [4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl) benzo [1,2- b: 4,5- b'] dithiophene] -bis (5-thiophen-2-yl) pyrrolo [3,4-c] -pyrrole-1,4-dione] [PBDTBPA (F) -DPP].

The polymer compound has a mass average molecular weight of 6000 g / mol to 150,000 g / mol. The mass average molecular weight is related to hole mobility. Hence, with a high mass average molecular weight, the hole mobility will also have a high value, resulting in a high current density value and therefore a high photoelectric conversion efficiency value.

According to another aspect of the present invention, there is provided an organic thin film solar cell, which is manufactured using the polymer compound.

According to still another aspect of the present invention, there is provided an organic thin film transistor characterized in that the organic thin film transistor is manufactured using the polymer compound.

According to another aspect of the present invention, there is provided an organic electroluminescent device comprising the polymer compound.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following examples, the benzodithiophene unit according to the present invention, the bis-toluene-containing polymer compound forming a partially integrated structure with the benzodithiophene, The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples.

Example

&Lt; Example 1 >

4,5-b '] dithiophene] -Alt- [(4'- (2-ethylhexyloxy) -3-ethynylbiphenyl] Pyrido [3,4-c] pyrrole-1,4-dione] [PBDTBPA (H) -DPP] / RTI >

1. Synthesis of ((3-bromophenyl) ethynyl) trimethylsilane (Formula 1).

(2 g, 8.41 mmol), bis (triphenylphosphine) palladium (II) dichloride (0.294 g, 5 mol%) and copper iodide (0.079 g, 5 mol%) were placed in a 50 mL flask . Then, triethylamine (10 mL) is added, and 30 mL of tetrahydrofuran (THF) is added. Then, trimethylsilylacetylene (1.198 mL, 8.41 mmol) was added at room temperature, followed by stirring for 3 hours. After termination of the reaction, the solvent was removed in vacuo and the product was extracted with methylene chloride (MC), and anhydrous sodium sulfate was added to remove the remaining solvent and evaporate to give a crude brown oil. After purification by column chromatography using silica gel as a stationary phase and hexane as an eluent, 1.6 g of a colorless liquid was obtained in a yield of 72%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.64 (d, 1H), 7.42 (m, 2H), 7.16 (m, 1H), 0.23 (s, 9H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 133.74, 132.46, 130.40, 128.12, 126.12, 125.74 103.68, 100.12, 0.00.

2. Synthesis of ((4 '- (2-ethylhexyloxy) biphenyl-3-yl) ethynyl) trimethylsilane (Formula 2).

2 M solution of sodium carbonate (10 mL) was added to 24 mL of toluene and the compound (1) (3 g, 11.8 mmol) synthesized above and 2- (4- (2-ethylhexyloxy) phenyl) 5,5, -tetramethyl-1,3,2-dioxaboroline (4.58 g, 14.2 mmol) and tetrakis (triphenylphosphine) palladium (0.136 g, 0.03 mmol) were added to the dissolved mixture. The mixture was refluxed in the presence of nitrogen gas for 12 hours. The solvent was removed in vacuo and the product was purified by column chromatography using silica gel as a stationary phase and ethyl acetate (EA) / hexane (4: 1) as eluent to give a colorless liquid in 60% yield . ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.66 (s, 1H), 7.48 (m, 3H), 7.34 (m, 2H), 6.96 (d, 2H), 3.84 (d, 2H), 1.64-1.78 (m, 1H), 1.22-1.54 (m, 8H), 0.84 (m, 6H), 0.26 (s, 9H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 158.84, 141.42,133.16,131.79,129.78,127.31,126.52,125.81,123.32,115.37,105.89,94.32,72.14,39.84,31.17,29.82,23.21,22.84 , 14.13, 11.84, 0.00.

3. Synthesis of 4 '- (2-ethylhexyloxy) -3-ethynylbiphenyl [BPA (H)].

Compound 2 (1.2 g, 3.12 mmol) was dissolved in 20 mL of methylene chloride (MC), and 1.4 g of potassium hydroxide was dissolved in 25 mL of methanol and then added. The reaction mixture was stirred at room temperature for 2 hours before being quenched with water (150 mL). It was then extracted with methylene chloride (MC), the anhydrous sodium sulfate was added to remove the remaining solvent and evaporated to give a crude yellow oil. The residue was purified by column chromatography using silica gel as a stationary phase and ethyl acetate (EA) / hexane (3: 1) as eluent to obtain 0.9 g of a colorless liquid in 83% yield. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.68 (s, 1H), 7.52 (t, 3H), 7.38 (m, 2H), 6.94 (d, 2H), 3.92 (d, 2H), 3.08 (s, 1H), 1.74 (m, 1H), 1.38 (m, 8H), 0.92 (m, 6H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 158.84, 141.42,133.16,131.79,129.78,127.31,126.52,125.81,123.32,115.37,84.31,72.14,39.84,31.17,29.82,23.21,22.84,14.13 , 11.84.

4. Synthesis of 4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynylbiphenyl) benzo [1,2- b: 4,5- b'] dithiophene synthesis.

(2-ethylhexyloxy) -3-ethynylbiphenyl (0.7 g, 2.9 mmol) and THF (25 mL) were added thereto at 0 ° C in the presence of nitrogen, ) &Lt; / RTI > The temperature of the reaction was raised to 50 캜 and stirred for 1.5 hours. Diiodothiophene-4,8-dione (0.3 g, 1.3 mmol) was added to the reaction at 50 < 0 >Lt; / RTI > and stirred at the same temperature for a time. After cooling the reaction to room temperature, the mixture was added with tin chloride dihydride (1.9 g, 19.75 mmol) in 15% HCl and further stirred for 1.5 hours before pouring into ice water. The reaction mixture was extracted with diethyl ether. The resultant was dried over anhydrous sodium sulfate, and the solvent was evaporated to obtain a crude brown oil. After purification by column chromatography using silica gel as a stationary phase and hexane as an eluent, 0.5 g of a yellow solid was obtained in a yield of 45%. ¹ H NMR (300 MHz, CDCl ₃ ):? (Ppm) 7.84 (s, 2H), 7.74 (d, 2H), 7.52-7.64 ), 3.84 (d, 4H), 1.74 (m, 2H), 1.32-1.48 (m, 14H), 0.78-0.98 (m, 12H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 158.84, 141.84, 140.42, 138.74, 132.14,129.76,122.21,125.79,123.52,115.43,115.21,112.26,99.89,86.24,71.31,39.84,31.17,29.82 , 23.21, 22.84, 14.13, 11.84.

Benzo [1,2-b: 4,5-b '] benzo [b] thiophene- Synthesis of dithiophene [BDTBPA (H)].

A solution prepared by dissolving Compound 3 (0.5 g, 0.6 mmol) in THF (30 mL) was placed in a 50 mL flask. The inside of the flask was filled with N ₂ , and dry ice was added to acetone. . To the cooled reaction was slowly dropped tert-BuLi (1.7 M, 0.73 mL) and further stirred at -78 ° C for 30 minutes, then trimethyltin chloride (0.25 g, 1.2 mmol) in solid form was added. The reaction was slowly warmed to room temperature and stirred overnight. Sodium carbonate solution (20 mL) was slowly added to the reaction and extracted with MC (30 mL). The organic layer having the product dissolved therein was dehydrated with anhydrous sodium sulfate, and the solvent was evaporated to obtain a yellow product. This was recrystallized from ethanol to obtain 0.45 g of a yellow solid in a yield of 64%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.86 (s, 2H), 7.76 (d, 2H), 7.54-7.66 (m, 8H), 7.44-7.50 (m, 2H), 6.98-7.04 (d, 4H), 3.92 (d, 4H), 1.72-1.78 (m, 2H), 1.28-1.52 (m, 16H), 0.82-0.98 (m, 12H), 0.39-0.58 (m, 18H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 159.294, 144.77, 143.68, 141.26, 139.08, 132.54, 130.89, 130.05, 129.97, 128.87, 128.19, 127.15, 123.46, 114.90, 98.63, 86.28, 70.57, , 30.54, 29.10, 23.86, 23.09, 14.15, 11.15, -8.18.

6. Preparation of poly [4,8- bis (4 '- (2-ethylhexyloxy) -3-ethynylbiphenyl) benzo [1,2- b: 4,5- b'] dithiophene- - [2,5-diethylhexyl-3,6-bis (5-thiophen-2-yl) pyrrolo [3,4- DPP].

BDTBPA (H) (200 mg, 0.5 mmol) and DPP (121 mg, 0.5 mmol) were dissolved in chlorobenzene (10 mL). Argon gas was added to the reaction for 15 minutes and Pd ₂ (dba) ₃ (6 mg, 2 mole%) and (o-tolyl) ₃ P (14 mg, 16 mole% Lt; / RTI > 5 times. The reaction was heated to 120 < 0 > C for 6 hours. After cooling to room temperature, the reaction product was poured into methanol to obtain crystals. Then, extraction with methanol, hexane, acetone, and chloroform was carried out by Soxhlet extraction and purification was carried out to obtain PBDTBPA (H) -DPP in a yield of 58%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 8.12-7.48 (m, 6H), 7.20-7.16 (m, 14H), 4.20-3.60 (m, 8H), 2.10-0.64 (64H); Anal. Calcd for C ₈₄ H ₉₂ N ₂ O ₄ S ₄ : C, 66.75; H, 6.20; O, 1.59; S, 25.46. Found: C, 76.56; H, 7.12; O, 4.98; S, 9.92.

&Lt; Example 2 >

Benzo [1,2-b: 4,5-b '] benzo [b] thiophene- 3,4-c] -pyrrole-l, 4-dione) < / RTI > [Synthesis of PBDTBPA (F) -DPP].

1. Synthesis of 4 '- (2-ethylhexyloxy) -2,4-difluorobiphenyl (Formula 4).

_{Na 2 CO 3 (2M, 15mL} ) for 1-bromo-4- (2-ethylhexyloxy) benzene (3g, 10mmol) and 2,4-difluorophenyl beam Nick Acid (2.15g, 13mmol) And tetrakis (triphenylphosphine) palladium (0.607 g, 0.1 mmol) were dissolved in toluene (24 mL) and ethanol (12 mL). The reaction was refluxed in the presence of N ₂ for 12 h. After cooling to room temperature, the reaction product was extracted with MC. The resultant was dried with anhydrous sodium sulfate and evaporated to give a crude brown oil. After purification by column chromatography using silica gel as a stationary phase and EA / hexane (4: 1) as an eluent, 3.2 g of a colorless liquid was obtained in a yield of 50%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.32- 7.46 (m, 3H), 6.82-6.98 (m, 4H), 3.92 (d, 2H), 1.72-1.80 (m, 1H), 1.22 -1.52 (m, 8H), 0.82-0.98 (m, 6H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 162.89, 161.47, 160.02, 159.28, 158.74, 132.93, 130.76,129.17,127.73,124.32,114.82,112.13,104.98,70.73,38.94,31.13,28.95,22.71 , 14.15, 11.15.

2. Synthesis of 4'-2 (ethylhexyloxy) -2,4-difluoro-3-iodobiphenyl (Formula 5).

A solution prepared by dissolving Compound 4 (2 g, 6.2 mmol) in THF (30 mL) was charged in a 50 mL flask, the inside of the flask was filled with N ₂ , the dry ice was added to acetone, and the solution was cooled in a vessel cooled to -78 ° C . LDA (2M in THF / pentane, 3.77 mL) was slowly added and the reaction was stirred for additional 30 min at 78 ° C before iodine (1.75 g, 6.9 mmol) was added to THF (20 mL) Solution. The reaction was slowly warmed to room temperature and stirred overnight. The reactants were extracted with water and then extracted with EA. The organic layer having the product dissolved therein was dehydrated with anhydrous sodium sulfate, and the solvent was evaporated to obtain a yellow product. After purification by column chromatography using silica gel as a stationary phase and EA / hexane (1: 1) as an eluent, 2.1 g of a colorless liquid was obtained in a yield of 70%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.28-7.44 (m, 3H), 6.84-7.02 (m, 3H), 3.84 (d, 2H), 1.72-1.80 (m, 1H), 1.22 -1.52 (m, 8H), 0.80-0.98 (m, 6H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 162.89, 161.47, 160.02, 159.28, 158.74, 132.93, 130.76,129.17,127.73,124.32,114.82,121.13,70.73,38.94,31.13,28.95,22.71,14.15 , 11.15.

3. Synthesis of ((4- (2-ethylhexyloxy) -2,4-difluorobiphenyl-3-yl) ethynyl) trimethylsilane (Formula 6).

Compound 5 (2 g, 4.51 mmol), bis (triphenylphosphine) palladium dichloride (0.105 g, 5 mol%) and copper iodide (0.025 g, 5 mol%) were placed in a 100 mL flask. The flask was then sealed with a rubber cap, vacuumed and refilled with argon three times. THF (25 mL) was added to triethylamine (10 mL) followed by addition. Then trimethylsilylacetylene (0.763 mL, 5.4 mmol) was added at room temperature and stirred for an additional 3 hours. After termination of the reaction, the solvent was removed in vacuo and the product was extracted with methylene chloride (MC), and anhydrous sodium sulfate was added to remove the remaining solvent and evaporate to give a crude brown oil. After purification by column chromatography using silica gel as a stationary phase and hexane as an eluent, 1.5 g of a colorless liquid was obtained in a yield of 83%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.34-7.42 (m, 3H), 6.92-6.98 (m, 3H), 3.84 (d, 2H), 1.68-1.82 (m, 1H), 1.22 -1.48 (m, 8H), 0.82-0.98 (m, 6H), 0.22-0.42 (s, 9H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 162.74,161.32,162.21,159.48,158.94,133.03,131.89,129.82,127.93,125.32,115.42,112.43,70.73,38.94,31.13,28.95,22.71,14.15 , 11.15, 0.00.

4. Synthesis of 4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl [BPA (F)].

To a mixture of Compound 6 (1.4 g, 3.3 mmol) dissolved in MC (30 mL), 1.6 g of potassium hydroxide was dissolved in methanol (25 mL) and added thereto. The reaction mixture was stirred at room temperature for 2 hours before being quenched with water (100 mL). It was then extracted with MC (100 mL) and anhydrous sodium sulfate was added to remove moisture and evaporate to give a crude yellow oil. After purification by column chromatography using silica gel as a stationary phase and EA / hexane (3: 1) as an eluent, 0.9 g of a colorless liquid was obtained in a yield of 78%. ¹ H NMR (300 MHz, CDCl ₃ ):? (Ppm) 7.32-7.46 (m, 3H), 6.92-7.04 (m, 3H), 3.92 (m, 1H), 1.32-1.52 (m, 8H), 0.82-0.98 (m, 6H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 162.74,161.32,162.22,159.48,158.94,133.03,131.89,129.82,127.93,125.32,115.42,112.43,86.42,70.73,38.94,31.13,28.95,22.71 , 14.15, 11.15.

Benzo [1,2-b: 4,5-b '] benzo [b] thiophene- Synthesis of dithiophenes (Formula 7).

To a mixture of 4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl (1.02 g, 2.9 mmol) in THF (25 mL) n-BuLi (2.5 M, 1.19 mL) was slowly dropped. The reaction was then increased to 50 캜, stirred for 1.5 hours and reacted at the same temperature with 4,8-dihydrobenzo [1,2-b: 4,5-b '] dithiophene-4,8- 0.3 g, 1.3 mmol) was added and stirred for 2 hours. The reaction was then cooled to room temperature and a solution of tin chloride dihydrate (1.9 g, 19.75 mmol) in 15% HCl (20 mL) was added and stirred for 1.5 h, then poured into ice water. The reaction product was extracted with diethyl ether, and the organic layer having the product dissolved therein was dehydrated with anhydrous sodium sulfate, and the solvent was evaporated to obtain a brown oil. After purification by column chromatography using silica gel as a stationary phase and hexane (1: 1) as eluent, 0.48 g of a yellow solid was obtained in a yield of 40%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.76-7.80 (d, 2H), 7.60-7.66 (d, 2H), 7.38-7.52 (m, 6H), 6.98-7.08 (m, 6H) , 3.92 (d, 4H), 1.72-1.78 (m, 2H), 1.28-1.52 (m, 16H), 0.82-0.98 (m, 12H). ^{13 C NMR (300 MHz, CDCl} 3): δ (ppm) 163.10, 159.73, 159.60, 159.32, 157.57, 140.26, 138.41, 130.74, 130.02, 129.99, 128.73, 128.53, 126. 40, 125.30, 125.13, 125.12, 114.62 , 111.73, 111.50, 111.17, 102.41, 95.34, 86.65, 70.50, 39.38, 30.52, 29.119, 23.86, 23.11, 14.16, 11.16.

6. Synthesis of 2,6- (trimethyltin) -4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynyl-2,4- difluorobiphenyl) benzo [ b: 4,5-b '] dithiophene [BDTBPA (F)].

A solution prepared by dissolving Compound 7 (1 g, 1.1 mmol) in THF (30 mL) was placed in a 50 mL flask. The inside of the flask was filled with N ₂ , and dry ice was added to acetone. . Tert-BuLi (1.7 M, 1.3 mL) was slowly added dropwise to the cooled reaction and further stirred at -78 ° C for 30 min before adding trimethyltin chloride (0.45 g, 2.2 mmol) in solid form. The reaction was slowly warmed to room temperature and stirred overnight. Sodium carbonate solution (20 mL) was slowly added to the reaction and extracted with MC (30 mL). The organic layer having the product dissolved therein was dehydrated with anhydrous sodium sulfate, and the solvent was evaporated to obtain a yellow product. This was recrystallized from ethanol to obtain 0.9 g of a yellow solid in a yield of 69%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 7.86 (s, 2H), 7.76 (d, 2H), 7.54-7.66 (m, 8H), 7.44-7.50 (m, 2H), 6.98-7.04 (d, 4H), 3.92 (d, 4H), 1.72-1.78 (m, 2H), 1.28-1.52 (m, 16H), 0.82-0.98 (m, 12H), 0.39-0.58 (m, 18H). ¹³ C NMR (300 MHz, CDCl ₃ ):? (Ppm) 163.13,159.86,159.73,159.48,157.67,141.47,138.61,130.92,130.18,130.03,128.82,128.56,126.60,125.39,125.23,125.18,111.86,111.62 , 111.24, 95.24, 86.85, 70.58, 39.48, 30.72, 29.31, 23.76, 23.21, 14.18, 11.22, -8.18.

7. Poly [4,8-bis (4 '- (2-ethylhexyloxy) -3-ethynyl-2,4-difluorobiphenyl) benzo [1,2- ] - dithiophene] -Alt- [2,5-diethylhexyl-3,6-bis (5-thiophen-2- yl) pyrrolo [3,4- Ion] [PBDTBPA (F) -DPP].

PBDTBPA (F) - DPP was synthesized by Stille polymerization method using microwave. The synthesis method of PBDTBPA (F) -DPP polymer was as follows. 10 mL microwave PBDTBPA (F) a monomer (200mg, 0.5 mmol), DPP (114 mg, 0.5 mmol), Pd 2 (dba) 3 (8 mg, 2 mole%) and (o-tolyl) to the tube ₃ P ( 18 mg, 16 mole%) was dissolved in anhydrous chlorobenzene (5 mL). The mixture was purged with N ₂ for 15 min. The microwave tube was then placed in the reactor and heated to 120 DEG C for 30 minutes. Thereafter, the reaction mixture was cooled to room temperature, and the reaction product was poured into methanol to obtain crystals. The crystals were extracted with methanol, hexane, acetone and chloroform in the order of Soxhlet extraction and purified to obtain PBDTBPA (F) -DPP in a yield of 47%. ^{1 H NMR (300 MHz, CDCl} 3): δ (ppm) 8.12-7.48 (m, 6H), 7.20-7.16 (m, 10H), 4.20-3.60 (m, 8H), 2.10-0.64 (64H); Anal. Calcd for C ₈₄ H ₈₈ F ₄ N ₂ O ₄ S ₄ : C, 72.38; H, 6.36; O, 4.59; S, 9.20. Found: C, 72.18; H, 6.14; 4.72; S, 9.42.

&Lt; Example 3 > Preparation of light energy conversion device using [PBDTBPA (H) -DPP].

In this example, Inverted Organic Solar Cells (IOSCs) were fabricated with different structures.

First, ITO coated glass used as a constituent was ultrasonically cleaned using a detergent, water, acetone, and isopropyl alcohol. ZnO precursor is zinc acetate dihydrate (Zn (CH ₃ COO) ₂ o 2H ₂ O, 1.64 g) and ethanol amine _{(NH 2 CH 2 CH 2 OH} , 0.5 g) is dissolved in a vigorously 20 2-methoxy-ethanol 10 g Lt; / RTI > for 1 minute and then hydrolyzed in air. The ZnO layer was spin cast into a precursor solution on a clean glass substrate coated with ITO and annealed in air at 150 ° C for 10 minutes. The photoactive layer was prepared by dissolving PBDTBPA (H) -DPP: PC ₇₁ BM in 1 mL of 1: 0.7, 1: 1.5 and 1: 2 in 1 mL of chlorobenzene and spin coating at 1200 rpm for 30 seconds in a N ₂ glove box lost. After drying in vacuum, treatment with various solvents was carried out. In Example 3-3, treatment was carried out using methanol. Finally, ~ 10 nm PEDOT: PSS (CLEVIOS PVP AI 4083): IPA (1:10 v / v%) and ~ 100 nm Ag layer were formed on the photoactive layer.

The structure of the fabricated device is shown in the following Examples 3-1 to 3-3.

Example 3-1: The device was fabricated with ITO / PEDOT: PSS (40 nm) / PBDTBPA (H) -DPP: PC ₇₁ BM (100 nm) / PEDOT: PSS (50 nm) / Al (100 nm).

Example 3-2: The device was fabricated with ITO / PEDOT: PSS (40 nm) / PBDTBPA (H) -DPP: PC ₇₁ BM (100 nm) + 3% DIO / PEDOT: PSS (50 nm) / A1 (100 nm)

Example 3-3: Device fabrication with ITO / PEDOT: PSS (40 nm) / PBDTBPA (H) -DPP: PC ₇₁ BM (100 nm) + 3% DIO (methanol treatment) / PEDOT: PSS (50 nm) / A1 Respectively.

The photovoltaic characteristics of the fabricated device were also measured. Specifically, the device's voltage-current characteristics (JV characteristics) were measured using an AM 1.5G solar simulator (Oriel Sol3A ™ Class AAA solar simulator, models 94043A) calibrated at 100 mW / cm ² using a Keithley 2400 . The intensity of the sunlight was measured using a standard silicon photodiode detector with adjustments in conjunction with a KG-5 filter. The IPCE measuring instrument (Oriel IQE-200) uses a 250 W quartz-tungsten halogen lamp as a light source and consists of a monochromator, a light chopper, a lock-in amplifier and a controlled silicon photodetector. All IOSCs data were based on results obtained by repeating 10 or more times under the same conditions. During the JV curve of the IOSCs, only a portion of the cells exposed to light emission were covered with a black cloth.

Example 4: Fabrication of a light energy conversion device using [PBDTBPA (F) -DPP].

First, the ITO coated glass used as a constituent was ultrasonically cleaned using a detergent, water, acetone, and isopropyl alcohol. ZnO precursor is zinc acetate dihydrate (Zn (CH ₃ COO) ₂ o 2H ₂ O, 1.64 g) and ethanol amine _{(NH 2 CH 2 CH 2 OH} , 0.5 g) is dissolved in a vigorously 20 2-methoxy-ethanol 10 g Lt; / RTI > for 1 minute and then hydrolyzed in air. The ZnO layer was spin cast into a precursor solution on a clean glass substrate coated with ITO and annealed in air at 150 ° C for 10 minutes. The photoactive layer was prepared by dissolving PBDTBPA (F) -DPP: PC ₇₁ BM in 1 mL of 1: 0.7, 1: 1.5 and 1: 2 in 1 mL of chlorobenzene and spin coating at 1200 rpm for 30 seconds in a N ₂ glove box lost. After drying in vacuum, treatment with various solvents was carried out. In Example 4-3, treatment was carried out using methanol. Finally, ~ 10 nm PEDOT: PSS (CLEVIOS PVP AI 4083): IPA (1:10 v / v%) and ~ 100 nm Ag layer were formed on the photoactive layer.

The structure of the fabricated device is shown in the following Examples 4-1 to 4-3.

Example 4-1: The device was fabricated with ITO / PEDOT: PSS (40 nm) / PBDTBPA (F) -DPP: PC ₇₁ BM (100 nm) / PEDOT: PSS (50 nm) / Al (100 nm).

Example 4-2: The device was fabricated with ITO / PEDOT: PSS (40 nm) / PBDTBPA (F) -DPP: PC ₇₁ BM (100 nm) + 3% DIO / PEDOT: PSS (50 nm) / Al (100 nm)

Example 4-3: Device fabrication with ITO / PEDOT: PSS (40 nm) / PBDTBPA (F) -DPP: PC ₇₁ BM (100 nm) + 3% DIO (methanol treatment) / PEDOT: PSS (50 nm) / A1 Respectively.

Hereinafter, the results of the above embodiments will be described with reference to the drawings.

1. Polymerization degree

1 is a graph showing the degree of polymerization of PBDTBPA (H) -DPP and PBDTBPA (F) -DPP synthesized in Example 1 and Example 2. FIG.

Referring to FIG. 1, the mass average molecular weight of the polymer was 71320 g / mol for PBDTBPA (H) -DPP and 24270 g / mol for PBDTBPA (F) -DPP by gel permeation chromatography (GPC) . From this, it can be seen that the polymerization of the polymers is well performed, and that the polymer has good solubility in organic solvents.

2. Thermal Stability

2 is a TGA (thermal gravimetric analysis) graph of PBDTBPA (H) -DPP and PBDTBPA (F) -DPP synthesized in Example 1 and Example 2. FIG.

Referring to FIG. 2, decomposition temperatures (T _d ) corresponding to [PBDTBPA (H) -DPP] of 412 ° C and [PBDTBPA (F) -DPP] of 421 ° C were found through TGA measurement. From this, it can be seen that the polymer has high thermal stability.

3. Charge mobility

FIG. 3 shows the charge mobility of the device fabricated in Example 3 and Example 4. FIG.

Referring to FIG. 3, μ _h of Example 3-2 is 6.55 × 10 ^-5 cm ² V ^-1 s ^-1 , μ _h of Example 4-2 is 3.37 × 10 ^-5 cm ² V ^-1 s ^-1 to be. From this, it can be seen that the charge mobility of the PBDTBPA (H) -DPP: PC ₇₁ BM device is better.

The measurement results of the charge mobility are summarized in Table 1.

Example Production conditions Hole mobility
( μ _h , cm ² V ^-1 s ^-1) Electron mobility
( μ _e , cm ² V ^-1 s ^-1) Charge balance
( μ _h / μ _e ) 3-1 pristine 1.04 x 10 ^-5 2.98 x 10 ^-4 0.03 3-2 3% DIO 6.55 x 10 ^-5 3.01 x 10 ^-4 0.21 3-3 methanol 1.76 x 10 ^-4 3.05 x 10 ^-4 0.58 4-1 pristine 8.25 x 10 ^-6 2.90 x 10 ^-4 0.02 4-2 3% DIO 3.37 x 10 ^-5 2.95 x 10 ^-4 0.11 4-3 methanol 7.44 x 10 ^-5 3.12 x 10 ^-4 0.23

4. Optical properties

FIG. 4 is a graph showing UV-Vis absorption spectra of chloroform solution and film state of PBDTBPA (H) -DPP and PBDTBPA (F) -DPP synthesized in Example 1 and Example 2. FIG.

Referring to FIG. 4, it can be confirmed that the synthesized polymer PBDTBPA (H) -DPP and PBDTBPA (F) -DPP have a wide absorption range ranging from 350 to 961 nm. Specifically λ _onset of the polymer measured in a film state is PBDTBPA (F) and -DPP is 961 nm, PBDTBPA (H) -DPP is found to be 892 nm. It was found that the F-substituted polymer had a long wavelength shift of 69 nm compared to the non-substituted polymer. This phenomenon was attributed to the two-dimensional interaction between the triple bond in PBDTBPA (F) -DPP and the lone electron pairs of fluorine atoms . The absorbed wavelength can be divided into a short wavelength absorption corresponding to a? -Π ^* transition and a long wavelength absorption caused by an intramolecular charge transfer transition. In each of the two polymers, two shoulders A peak can be seen.

The optical bandgap (E _g ^opt ) of the polymer was calculated as the point where absorption starts. PBDTBPA (H) -DPP was 1.39 eV and PBDTBPA (F) -DPP was 1.29 eV. Also, all of the above polymers have a wider absorption region and have a longer wavelength shift when measured in a film state than in a chloroform solution. The PBDTBPA (F) -DPP showed a long wavelength shift of 27 nm in the film state compared to the solution state, compared with the PBDTBPA (H) -DPP solution state, F) -DPP has a stronger interaction between the polymer chains than PBDTBPA (H) -DPP. The maximum wavelength absorption value (? _Max ) and the optical band gap (E _g ^opt ) are summarized in Table 2.

5. Electrochemical Properties

5 is a graph showing CV (cyclic voltammogram) spectra of PBDTBPA (H) -DPP and PBDTBPA (F) -DPP synthesized in Example 1 and Example 2. FIG.

5, the HOMO energy level of PBDTBPA (H) -DPP was? 5.25 eV, and the HOMO energy level of PBDTBPA (F) -DPP was? 5.20 eV. Since the HOMO energy level of the PBDTBPA (F) -DPP acts as a strong electron donor in BPDTBPA (H) -DPP and BPA (H) acts as a weak electron donor in the PBDTBPA (H) The HOMO energy level of the HOMO layer is decreased. LUMO value of the polymer is E _g ^opt can be obtained by using the (E _LUMO _HOMO = E + E _g ^opt), PBDTBPA LUMO value of (H) -DPP is ?? 3.86 eV, PBDTBPA (F) of the LUMO -DPP The value was? 3.90 eV. The CV measurement values are summarized in Table 2 below.

Polymer solution
? _max (nm) film
? _max (nm) E _g ^opt
(eV) HOMO
(eV) LUMO
(eV) PBDTBPA (H) -DPP 533 552 1.39 -5.25 -3.86 PBDTBPA (F) -DPP 523 550 1.29 -5.20 -3.91

6. Photovoltaic properties

6 and 7 are graphs showing the current density-voltage ( J - V ) of the device manufactured in Example 3 and Example 4 and the photoelectric conversion efficiency (PCE) value showing the lifetime of the device with time .

6 and 7, FIG. 6A shows the devices of Examples 3-2 and 3-3, wherein each polymer and PC ₇₁ BM were blended in a ratio of 1: 1.5, and the polymer was obtained by dissolving chlorobenzene in a solvent . The device produced in Example 3-2 showed a photoelectric conversion efficiency (PCE) value of 4.62%, V _oc is 0.73 V, short-circuit current density (J sc) is 12.36 mA / cm ^2, and the fill factor (FF ) Was 51.21%. The device manufactured in Example 3-3 showed the highest photoelectric conversion efficiency (PCE) value of 5.58%, V _oc value of 0.74 V, J _sc of 13.17 mA / cm ² , and FF of 57.28%.

FIG. 6 (b) shows the devices of Examples 4-2 and 4-3 in which each polymer and PC ₇₁ BM were blended in a ratio of 1: 1.5, and the polymer was measured by dissolving chlorobenzene in a solvent. The device manufactured in Example 4-2 had the lowest photoelectric conversion efficiency (PCE) value of 3.04%, V _oc value of 0.68 V, J _sc of 9.49 mA / cm ² , and FF of 46.99%. The device manufactured in Example 4-3 exhibited a photoelectric conversion efficiency (PCE) value of 4.04%, V _oc of 0.68 V, J _sc of 11.81 mA / cm ² , and FF of 50.53%.

7A is a graph showing the device of Example 3-3, and FIG. 7B is a graph showing the photoelectric conversion efficiency (PCE) of the device of Example 4-3. It is confirmed that the efficiency of the device of Example 3-3 based on PBDTBPA (H) -DPP is 5.58% higher than that of the device of Example 4-3 which is based on PBDTBPA (F) -DPP of 4.04% . Also, the PCE value of the Example 3-3 was about 5.0% after 30 days, and the PCE value was 4.65% after 60 days. In the case of Example 4-3, after 30 days, the PCE value was about 3.5%, and after 60 days, the PCE value was 3.2%. From these results, it can be confirmed that the PCE value of the device made of the two polymer compounds is maintained without a large change over a long period of time, and thus is very stable.

Based on the above results, it can be seen that PBDTBPA (F) -DPP containing fluorine atoms has worse results than PBDTBPA (H) -DPP in photoelectric properties. The photoelectric conversion efficiency (PCE) value of 5.58% is based on the BDT reported so far and is the highest value among the polymers having arylethynyl (arylethynyl) as a substituent. The results of the current density-voltage ( J - V ) and photoelectric conversion efficiency (PCE) values are summarized in Table 3 below.

Example 3%
DIO MeOH
process J _sc (mA / cm ² ) V _oc (V) FF (%) PCE (%) 3-1 N N 8.22 ± 0.10 0.72 ± 0.01 49.32 + 1.67 2.88 ± 0.05 3-2 Y N 12.36 + - 0.10 0.73 ± 0.01 51.21 + - 0.70 4.62 + - 0.10 4-1 N N 7.71 + - 0.42 0.66 + 0.03 37.89 ± 1.68 1.92 + - 0.10 4-2 Y N 9.49 + 0.16 0.68 ± 0.01 46.99 ± 1.03 3.04 ± 0.16 3-3 Y Y 13.17 ± 0.12 0.74 ± 0.01 57.28 ± 1.59 5.58 0.20 4-3 Y Y 11.81 + - 0.10 0.68 ± 0.01 50.53 + - 0.29 4.04 + 0.07

8 is a graph showing the external quantum efficiency (EQE) of the device manufactured in Examples 3 to 4. FIG.

Referring to FIG. 8, the external quantum dot transmittance of the prepared device was in the wide range of 350-961 nm, similar to the (EQE) UV-Vis absorption spectrum. The external quantum efficiency (EQE) values of Example 3 and Example 4 after the photoactive layer of the device was treated with methanol increased with the photocurrent value. The increase of the external quantum efficiency value as mentioned above can expect a high hole mobility and an appropriate phase separation, which can result in an increase in J _sc and FF . Also, J _sc can be obtained by integrating the external quantum efficiency spectrum, which agrees with the J _sc obtained from the J - V measurement within a 5-10% error range.

From the results of the above examples, the present invention has synthesized a benzodithiophene unit and a polymer compound including bis-tolane which forms a partially integrated structure with the benzodithiophene, and the polymer compound has high thermal stability , A high charge mobility, and a wide range of light absorption regions and appropriate HOMO and LUMO values, the excitons can be well formed and the movement of electrons and holes can be smooth. In addition, it was confirmed that the device fabricated from the polymer compound had a high photoelectric conversion efficiency and that the photoelectric conversion efficiency was not significantly decreased for 60 days, so that the device made of the polymer compound was stable.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims

A polymer compound comprising a benzodithiophene unit and bis-tolyl that partially forms an integrated structure with the benzodithiophene, and is represented by the following formula (1).
[Chemical Formula 1]

(Wherein n is an integer of 5 to 100,
Of _{R 1, R 2, R 3} , R 5, R 6, R 8, R 9 and R ₁₀ are each independently the same or different H, F, Br, Cl, NO 2 together, CN, C _1-20 A linear or branched alkyl group, and a C _1-20 linear or branched alkoxybenzene group,
R ₁₁ is a C _1-20 linear or branched alkyl group,
A is an electron acceptor aromatic compound.)

delete

The method according to claim 1,
Wherein A is

,

or

. &Lt; / RTI >
(Wherein R < ₁₂ > and R < ₁₃ > are each independently a linear or branched alkyl group having from 1 to _{20 carbon atoms} ,

The method according to claim 1,
Wherein the polymer compound is any one selected from compounds represented by the following Chemical Formulas (2) to (4).
(2)

(3)

[Chemical Formula 4]

(Wherein n is an integer of 5 to 100,
Of _{R 1, R 2, R 3} , R 5, R 6, R 8, R 9 and R ₁₀ are each independently the same or different H, F, Br, Cl, NO 2 together, CN, C _1-20 A linear or branched alkyl group, and a C _1-20 linear or branched alkoxybenzene group,
R ₁₁ is a C _1-20 linear or branched alkyl group,
R ₁₂ and R ₁₃ are C _1-20 linear or branched alkyl groups.)

5. The method of claim 4,
Wherein the polymer compound is represented by the following formula (5) or (6).
[Chemical Formula 5]

[Chemical Formula 6]

(Wherein n is an integer of 5 to 100).

The method according to claim 1,
Wherein the polymer compound has a mass average molecular weight of 10,000 g / mol to 150,000 g / mol.

Wherein the solar absorbing photoactive layer comprises the polymer compound according to any one of claims 1 to 6.

An organic thin film transistor comprising the polymer compound according to any one of claims 1 to 6 as an active material.

An organic electroluminescent device comprising the polymer compound according to any one of claims 1 and 6 as an active material.