KR101251447B1 - Heterocyclic Compounds and Organic Solar Cell Including the same - Google Patents

Abstract

상기 화학식에서, R1은 수소원자, 할로겐원자, 알킬기, 알콕시기, 헤테로알킬기, 시아노기, 니트로기, 아실기, 치환 아미노기, 비치환 아미노기, 치환 아릴기 또는 비치환 아릴기 중에서 선택되고, R2는 수소원자, 할로겐원자, 알킬기, 알콕시기, 헤테로알킬기, 시아노기, 니트로기, 아실기, 치환 아미노기, 비치환 아미노기, 치환 아릴기 또는 비치환 아릴기 중에서 선택되고, R3는 수소원자, 할로겐원자, 알킬기, 알콕시기, 헤테로알킬기, 시아노기, 니트로기, 아실기, 치환 아미노기, 비치환 아미노기, 치환 아릴기 또는 비치환 아릴기 중에서 선택되고, R4는 수소원자, 할로겐원자, 알킬기, 알콕시기, 헤테로알킬기, 시아노기, 니트로기, 아실기, 치환 아미노기, 비치환 아미노기, 치환 아릴기 또는 비치환 아릴기 중에서 선택되며, X는 S 혹은 O 중에서 선택되고, Y는 S 혹은 O 중에서 선택되며, n은 1에서 30사이의 정수임.The present invention provides an organic solar cell including a first electrode and a second electrode facing each other and a photoactive layer positioned between the first electrode and the second electrode and including a heterocyclic compound of the following formula: .
[Chemical Formula]

In the above formula, R1 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group, and R2 is A hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group, and R3 is a hydrogen atom, a halogen atom, An alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group, R4 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, hetero An alkyl group, cyano group, nitro group, acyl group, substituted amino group, unsubstituted amino group, substituted aryl group or unsubstituted aryl group, X is selected from S or O, Y is selected from S or O, n is an integer from 1 to 30.

Description

Heterocyclic Compounds and Organic Solar Cell Including the same}

The present invention relates to an organic solar cell comprising a heterocyclic compound and a heterocyclic compound.

There is a need for clean and unlimited energy that is different from the existing energy such as the crisis of exhaustion of oil resources, the entry into force of the Kyoto Protocol's climate change agreement, and the explosive demand for energy due to the economic growth of emerging developing countries. This is going on.

Among the renewable energy, solar cells are the core elements of photovoltaic power generation that converts sunlight directly into electricity, and are widely used for power supply from space to home.

Such solar cells mainly use silicon or compound semiconductors, but silicon or compound semiconductor solar cells are manufactured in a semiconductor device manufacturing process and thus have high manufacturing costs. In particular, silicon solar cells, which occupy a major portion of solar cells, have difficulty in supplying and receiving silicon raw materials.

Under these circumstances, organic solar cells that do not use silicon materials have begun to be studied in earnest, and demand for highly efficient organic solar cells is increasing.

In this background, an object of the present invention is to provide an organic solar cell having high photoelectric conversion efficiency.

In order to achieve the above object, in one aspect, the present invention provides a heterocyclic compound represented by the following formula.

[Chemical Formula]

In the above formula, R 1 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

R2 is selected from hydrogen atom, halogen atom, alkyl group, alkoxy group, heteroalkyl group, cyano group, nitro group, acyl group, substituted amino group, unsubstituted amino group, substituted aryl group or unsubstituted aryl group,

R3 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

R4 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

X is selected from S or O, Y is selected from S or O, and n is an integer from 1 to 30.

In another aspect, the present invention provides an organic embodiment comprising a photoactive layer including a first electrode and a second electrode facing each other, and a photoactive layer positioned between the first electrode and the second electrode and including a heterocyclic compound of the formula Provide a battery.

[Chemical Formula]

In the above formula, R 1 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

R2 is selected from hydrogen atom, halogen atom, alkyl group, alkoxy group, heteroalkyl group, cyano group, nitro group, acyl group, substituted amino group, unsubstituted amino group, substituted aryl group or unsubstituted aryl group,

R3 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

R4 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group,

X is selected from S or O, Y is selected from S or O, and n is an integer from 1 to 30.

As described above, the organic solar cell of the present invention can increase the photoelectric conversion efficiency by including a new heterocyclic compound.

1 shows an organic solar cell according to an embodiment of the present invention.
2 is a voltage-current density measurement result of a comparative example of an organic solar cell not containing a heterocyclic compound.
3 is a voltage-current density measurement result of an organic solar cell including a heterocyclic compound according to Example 1 of the present invention.
Figure 4 shows the preparation of the heterocyclic compound used in Example 1 of the present invention.
5 is a voltage-current density measurement result of an organic solar cell including a heterocyclic compound according to Example 2 of the present invention.
Figure 6 shows the preparation of the heterocyclic compound used in Example 2 of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings.

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.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements.

When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

Next, an organic solar cell including a heterocyclic compound and a heterocyclic compound according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 shows an organic solar cell according to an embodiment of the present invention. As shown in FIG. 1, an organic solar cell according to an exemplary embodiment of the present invention includes a substrate 100, a first electrode 101, a photoactive layer 103, and a second electrode 105. At this time, the first electrode 101 and the second electrode 105 face each other.

The first electrode 101 may be made of a transparent conductive material having a higher work function than the second electrode 105. In this case, the transparent conductive material may include indium tin oxide (ITO).

The photoactive layer 103 comprises a donor material, an acceptor material and a heterocyclic compound. The photoactive layer 103 may have a two-layered structure of a donor material and an acceptor material, or may have a composite thin film structure in which a donor material and an acceptor material are mixed. In addition, the photoactive layer 103 may include a composite thin film positioned between the donor material and the acceptor material in addition to the donor material and the acceptor material having a two-layer structure. The heterocyclic compound is described in detail later.

In this case, the photoactive layer 103 may include 30 to 80% by weight of donor material, 10 to 65% by weight of acceptor material, and 0.1 to 20% by weight of heterocyclic compound. If the donor material, acceptor material, and heterocyclic compound are not in such proportions, the phase of one element becomes larger than that of the other elements, making it difficult to transfer charges and recombination before reaching the interface. May occur. Therefore, when the photoactive layer 103 contains 30 to 80% by weight of donor material, 10 to 65% by weight of acceptor material, and 0.1 to 20% by weight of heterocyclic compound, proper phase separation of each element is achieved, thereby achieving high efficiency.

The second electrode 105 is made of a material having a lower work function than the first electrode 101 and may include Al, Ca, or the like.

When light is incident on the organic solar cell according to the exemplary embodiment of the present invention, the light reaches the photoactive layer 103 via the substrate 100 and the first electrode 101. Light is absorbed by the donor material present in the photoactive layer 103 to form an electron-hole pair in an excited state.

The electron-hole pairs diffuse in any direction and then split into electrons and holes when they meet the interface of the acceptor material. That is, the electrons move to the acceptor material with high electron affinity, and the holes remain in the donor material, and the electron-hole pair is separated into electrons and holes.

Separated electrons and holes are collected and moved to each electrode by the concentration difference between the internal magnetic field and the charge formed by the work function difference between the first electrode 101 and the second electrode 105, and finally the current through the external circuit. Flows in the form of.

On the other hand, the organic solar cell according to an embodiment of the present invention serves as a buffer layer and the hole transport layer 102 located between the first electrode 101 and the photoactive layer 103, and serves as a buffer layer, the photoactive layer An electron transport layer 104 may be further included between the 103 and the second electrode 105 having a lower work function than the first electrode 101. That is, the hole transport layer 102 facilitates the movement of holes to the first electrode 101 having a high work function, and the electron transport layer 104 prevents electrons from moving to the second electrode 105 having a low work function. To facilitate.

Next, a method of manufacturing an organic solar cell according to an embodiment of the present invention is described above.

<Formation and Cleaning Process of Substrate and First Electrode>

When light is incident through the substrate 100, the substrate 100 may be formed of a material having light transparency, may be made of a colorless transparent material, or may be colored. For example, the substrate 100 may include a transparent glass substrate such as soda-lime glass or an alkali free glass, or a plastic film such as polyester, polyamide, or epoxy resin.

The first electrode 101 may be made of a transparent conductive material. For example, the first electrode 101 may include In ₂ O ₃ , indium-tin oxide (ITO), indium-galliumzincoxide (IGZO), ZnO, aluminum-zinc oxide (ZnO: Al), SnO ₂ , FTO ( Fluorine-dopedtin oxide (SnO ₂ : F), ATO (Aluminum-tin oxide; SnO ₂ : Al), etc., such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), aluminum (Al) and It may be a single or complex oxide of the same metal.

The first electrode 101 may be formed by DC sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel coating, electroplating, or the like. The thickness of the first electrode 101 may be 100 nm or more and 1,000 nm or less.

The first electrode 101 formed on the substrate 100 may be immersed in acetone, alcohol, water, or a mixed solution thereof, and then ultrasonically cleaned.

<Formation of hole transport layer>

The hole transport layer 102 transports holes and blocks electrons. For example, the hole transport layer 102 may include PEDOT: PSS [poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate)], G-PEDOT [poly (3,4-ethylenedioxythiophene): poly (4-styrene sulfonate). ): polyglycol (glycerol)], PANI: PSS [polyaniline: poly (4-styrene sulfonate)], PANI: CSA (polyaniline: camphor sulfonic acid), PDBT (poly (4,4'-dimethoxy bithophene)], arylamine It may be made of one or more selected from the group consisting of a low molecular material or high molecular material having an aryl amine group, a low molecular material or high molecular material having an aromatic amine group.

The hole transport layer 102 may be formed by spin coating, spray coating, screen printing, bar coating, doctor blade coating, or the like. It may be formed by thermal evaporation under vacuum. The thickness of the hole transport layer 102 may be 5 nm or more and 300 nm or less.

<Photoactive Layer Formation>

The photoactive layer 103 comprises a donor material, an acceptor material and a heterocyclic compound.

The donor material may be made of a low molecular compound such as a phthalocyanine pigment such as copper phthalocyanine (CuPc), an indigo pigment, a thioindigo pigment, a melocyanine compound, or a cyanine compound. In addition, the donor material is poly-para-phenylene vinylene derivatives, vinyl-series polymers, such as (poly- ρ -phenylenevinylene), or poly [[9- (1-octylnonyl ) -9H-carbazole-2,7-diyl] -2 , 5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] (PCDTBT), poly [2,6- (4,4-bis- (2-ethylhexyl) -4H- thiophene compounds such as cyclopenta [2,1-b; 3,4-b1] dithiophene) -alt-4,7- (2,1,3-benzothiadiadiazole)] (PCPDTBT), poly (3-hexylthiophene) (P3HT) It may be made of a conductive polymer containing a polymer derivative.

Acceptor materials are fullerene (C60), [6,6] -phenyl-C61-butyric acid methyl ether ([6,6] -phenyl-C61-butyric acid methyl ether; PCBM), [6,6 Fullerene derivatives, such as] -phenyl-C71-butyric acid methyl ether, perylene, and 3,4,9,10-peptide Selected from the group consisting of perylene derivatives such as 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTBBI), and semiconductor nanoparticles such as ZnO, TiO ₂ , CdS, CdSe, or ZnSe It may be made of one or more. In this case, the size of the nanoparticles may be 1 nm or more and 100 nm or less, but is not limited thereto.

The heterocyclic compound included in the photoactive layer 103 of the organic solar cell according to the embodiment of the present invention may be represented by the following formula (1).

[Formula 1]

In formula 1, R 1 is selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group, and R 2 is Hydrogen atom, halogen atom, alkyl group, alkoxy group, heteroalkyl group, cyano group, nitro group, acyl group, substituted amino group, unsubstituted amino group, substituted aryl group or unsubstituted aryl group, R3 is selected from hydrogen atom, halogen atom, An alkyl group, an alkoxy group, a heteroalkyl group, a cyano group, a nitro group, an acyl group, a substituted amino group, an unsubstituted amino group, a substituted aryl group or an unsubstituted aryl group, R4 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, hetero Alkyl group, cyano group, nitro group, acyl group, substituted amino group, unsubstituted amino group, substituted aryl group or unsubstituted aryl group. X is selected from S (sulfur atom) or O (oxygen atom), and Y is selected from S (sulfur atom) or O (oxygen atom). n is an integer from 1 to 30.

The photoactive layer 103 is formed using a solution in which the donor material, the acceptor material, and the heterocyclic compound are dissolved or dispersed. At this time, a polar solvent such as chloroform, chlorobenzene, 1,2-dichlorobenzene, toluene may be used as the solvent. The photoactive layer 103 may be formed by spin coating, spray coating, screen printing, or the like.

<Electronic transport layer>

The electron transport layer 104 may be formed by an inkjet method, an offset printing method, a gravure printing method, or the like by using a metal precursor sol or a metal precursor solution. In addition, the electron transport layer 140 may be formed by the printing method described above using an ink, a slurry, or a paste prepared by dispersing an n-type metal oxide nanoparticle doped with impurities in a dispersion medium with an additive. .

The metal precursor sol may be a TiOx (1 <x <2) sol. The metal precursor solution may be a Cs ₂ CO ₃ solution or a titanium (diisoproxide) bis (2,4-pentadionate) solution. The metal oxide nanoparticles may be ZnO-based nanoparticles, Doped-ZnO (ZnO: Al, ZnO: B, ZnO: Ga, ZnO: N, etc.) nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, or TiO ₂ nanoparticles. Can be.

Accordingly, the electron transport layer 104 is a metal oxide, ZnO-based nanoparticles, Doped-ZnO-based nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles, TiOx (1 <x <2), Cs ₂ CO ₃ , titanium (diisoproxide) bis (2,4-pentadionate) may be made of one or more selected from the group consisting of.

<Formation of Second Electrode>

The second electrode 105 collects electrons generated in the photoactive layer 103. The work function of the second electrode 105 is smaller than the work function of the first electrode 101, and may be formed of a metal, an alloy, an electrically conductive compound, and a mixture thereof.

The second electrode 105 may be made of an alkali metal, a halide of an alkali metal, an oxide of an alkali metal, rare earths, and an alloy thereof with other metals. For example, the second electrode 105 may include a sodium-potassium alloy, a magnesium-silver mixture, an aluminum-lithium alloy, and an aluminum-lithium fluorine bilayer. The second electrode 105 may be formed by sputtering or vacuum deposition, but is not limited thereto.

<Sealing process>

Since the organic solar cell may be degraded by moisture and oxygen during operation, it is necessary to block each layer of the organic solar cell from the atmosphere. To this end, a moisture absorbing material capable of absorbing moisture is attached to the center of the protective cap made of a glass material, and a sealing material is dispensed to the rim of the protective cap.

An organic solar cell including the substrate 100, the first electrode 101, the hole transport layer 102, the photoactive layer 103, the electron transport layer 104, and the second electrode 105 is disposed on the dispensed sealing material. After UV or heat is applied, the sealing material hardens.

If the sealing material is cured using UV, measures should be taken to prevent UV light from flowing into the photoactive layer 103. This is because the photoactive layer 103 and the like may be deteriorated by UV.

In addition to the method described above, a sealing method for forming a multilayer thin film under vacuum may be used.

Next, an organic solar cell according to an exemplary embodiment of the present invention will be described in detail through a comparative example of an organic solar cell including a heterocyclic compound and an organic solar cell not including a heterocyclic compound.

Comparative Example 1

Comparative Example 1 is an organic solar cell that does not contain a heterocyclic compound.

A first electrode 101 made of ITO is formed on the substrate 100. At this point, ITO has a sheet resistance of 15 Ω / sq and a thickness of 1,500 Å.

The substrate 100 on which the first electrode 101 is formed is immersed in acetone, semicoclean (manufactured by Pulch Science, Inc.), isopropyl alcohol (manufactured by Duksan Chemical Co., Ltd.), and ultrasonically cleaned for 15 minutes and then dried. In the atmospheric plasma surface treatment apparatus, the substrate 100 on which the first electrode 101 is formed is treated for three minutes.

Spin coating is performed with polyethylenedioxythiophene: polystyrenesulfonate (manufactured by Stalk, PEDOT: PSS) to form a hole transport layer 102 having a film thickness of 40 nm on the first electrode 101. The substrate 100 on which the first electrode 101 and the hole transport layer 102 are formed is dried at 140 ° C. for 15 minutes and then transferred to a glove box in a dry nitrogen atmosphere having a dew point of −76 ° C. or less and 1 ppm or less of oxygen.

15 mg of regioregular polytrihexylthiophene (referred to as P3HT) as donor material and [6,6] -phenylC61-butyric acid methyl ester (Nano-C), a fullerene derivative as acceptor material First, a solution formed by dissolving 12 mg in 1 mL of chlorobenzene is applied on the hole transport layer 102 by spin coating. As a result, a photoactive layer 103 having a film thickness of 100 nm is formed, and the photoactive layer 103 is dried at 50 ° C. for 40 minutes.

Subsequently, the substrate 100 is set in a vacuum deposition apparatus, and a lithium fluoride having a thickness of 0.5 nm is formed on the photoactive layer 103, and an Al thin film having a thickness of 100 nm is formed on the photoactive layer 103 by vacuum deposition. 2 electrodes 105 are formed.

As such, the substrate 100 on which the second electrode 105 is formed is moved to a glove box of a nitrogen atmosphere, and an organic solar cell is manufactured through a sealing process. The fabricated organic solar cell is heat-treated for 30 minutes on a hot plate set at 150 ° C.

The voltage-current density of the organic solar cell to which the heterocyclic compound was not added in Comparative Example 1 was measured using Keithley 236 Source Measurement and Solar Simulator (300W simulator models 81150 and 81250, Spectra physics Co.) under standard conditions (AM 1.5). , 100 mW / cm ² , 25 ° C). As such, the organic solar cell having no heterocyclic compound had a Voc value of 0.63 V, a Jsc value of 8.07 Ma / cm ² , a curve factor of 60.3%, and a photoelectric conversion efficiency of 3.1%.

Example 1

2,2 ', 5,5'-tetrathiophene-3, a heterocyclic compound, was prepared in a solution prepared by dissolving 15 mg of P3HT and 12 mg of PCBM, a fullerene derivative, in 1 mL of chlorobenzene in the solar cell manufacturing process shown in Comparative Example 1. An organic solar cell was manufactured in the same manner except that 10 wt% of 3'-hexyl-dithiophene (TTHT) was added to form the photoactive layer 103.

As shown in FIG. 3, the organic solar cell had a Voc value of 0.68 V, a Jsc value of 16.7 mA / cm ² , and a curve factor of 69% according to Example 1 of the present invention. The conversion efficiency was 7.8%.

Figure 4 shows the manufacturing process of the heterocyclic compound TTHT contained in the organic solar cell according to an embodiment of the present invention.

After replacing the air in the first three-necked round bottom flask with Ar, magnesium (1.43 g, 0.058 mol) and 20 ml of purified dry ether in a first three-neck round bottom flask were After filled in it is maintained at 40 ℃. In addition, 1,6-dibromohexane (4.78 g, 0.0196 mol) is dropped into the inside of the first three-neck round bottom flask using a dropping funnel. The three-neck round bottom flask is then stirred for three hours while maintaining the temperature of the first three-neck round bottom flask at 50 ° C.

After the air inside the second three-neck round bottom flask is also replaced by Ar, 3-bromothiophene (8 g, 0.049 mol) is charged to the second three-neck round bottom flask. In addition, 30 ml of purified dry ether was placed in a second three-neck round bottom flask and 0.1 g of [1,3-bis (diphenylphosphino) -propan] nickel (II) dichloride was added. It is stirred at ℃.

Magnesium bromide made from the first three-neck round bottom flask is dropped into the second three-neck round bottom flask through a dropping funnel using a syringe. The second three neck round bottom flask was then kept at 60 ° C. and stirred for 6 hours.

After the reaction, the extraction is performed using chloroform. The organic layer of the second three-neck round bottom flask was collected to remove the solvent from the organic layer, and precipitated the organic layer from which the solvent was removed by using methanol (methanol) to generate a white solid 3,3'-hexyl-dithiophene. Filtering with methanol yields 3.4 g (70%) of 3,3'-hexyl-dithiophene as a white solid.

The white solid thus obtained was analyzed by ¹ H-NMR spectroscopy (300 MHz, reference solvent CDCl ₃ ) to determine 7.37-7.34 (m, 2H), 3.08-3.03 (t, 2H), 2.08-1.98 (m, 2H), You can get results like 1.84-1.69 (m, 2H).

Next, 3,3'-hexyl-dithiophene (6 g, 0.01198 mol) was dissolved in 40 mL of THF (Tetrahydrofuran), and then N-bromosuccimide (NBS, 12.8 g, 0.072 mol) was added at room temperature at 60 ° C. Stir for 12 hours.

After the reaction was completed, the solvent of the organic layer was removed, and then a light gray solid product (2,2 ', 5,5'-tetrabromo-3,3'-hexyl) was purified using column chromatography (ethylacetate / hexane, 1: 4v / v). 5.28 g (78%) of dithiophene are obtained.

The solid product thus prepared was analyzed by ¹ H-NMR spectroscopy (300MHz, reference solvent CDCl ₃ ) such as δ 6.77 (s, 1H), 2.54-2.48 (t, 2H), 1.56-1.26 (m, 4H) You can get the result.

Then, under a N ₂ atmosphere, 2,2 ', 5,5'-tetrabromo-3,3' -hexyl-dithiophene (2 g, 2 mmol), tributyl-thiophen- stannane (3.3ml, 10 mmol), PdCl 2 ( PPh ₃ ) ₂ (0.12 g, 0.2 mmol) is dissolved in dry THF (50 mL) and stirred at 60 ° C for 24 h. When the reaction is complete the solvent is removed and the reaction is worked up with CH ₂ Cl ₂ . Moisture is removed from the organic layer after work-up using MgSO ₄ . After the solvent in the organic layer was removed, TTHT (2,2 ', 5,5'-tetrathiophene-3,3'-, a pale yellow solid product, was purified using silicagel column chromatography (dichloromethane / hexane, 1: 4 = v / v). hexyl-dithiophene) 0.6 g (52%) was obtained.

When the pale yellow solid product is analyzed by ¹ H-NMR spectroscopy (reference solvent CDCl ₃ ) δ 7.25-7.24 (dd, 1H), 7.17-7.15 (dd, 1H), 7.12-7.10 (dd, 1H), 7.09 -7.07 (dd, 1H), 7.02 (s, 1H), 7.01-6.98 (dd, 1H), 6.97 6.95 (dd, 1H), 2.71 2.66 (t, 2H), 1.64-1.60 (m, 2H), 1.38 Results such as -1.37 (m, 2H) can be obtained.

Example 2

15 mg of PCPDTBT and 12 mg of PCBM, a fullerene derivative, were dissolved in 1 mL of chlorobenzene in the solar cell manufacturing process shown in Comparative Example 1 to a heterocyclic compound 2,2 ', 5,5'-tetrathiophene- Organic solar cells were prepared in the same manner except that 3,3'-propyl-difuran (TTPF) was added by 14 wt%.

As shown in FIG. 5, the organic solar cell manufactured according to Example 2 had a Voc value of 0.69 V, a Jsc value of 17.0 mA / cm ² , a curve factor of 69%, and a photoelectric conversion efficiency of 8.1%. .

Figure 6 shows the preparation of the heterocyclic compound used in Example 2 of the present invention.

Synthesis of 3,3'-propyl-difuran was carried out under reaction conditions similar to the synthesis of 3,3'-hexyl-dithiophene presented in Example 1 above. That is, magnesium and dry ether are injected into the first flask, and 1,6-dibromopropane is dropped into the first flask at 40 ° C. The first flask is then stirred for 4 hours while the temperature is maintained at 50 ° C.

After the addition of 3-bromofuran and dry ether in the first flask and the second flask, the second flask was sufficiently filled at 70 ° C. after [1,3-bis (diphenylphosphino) -propan] nickel (II) dichloride was added. It is stirred.

After magnesium bromide made in the first flask was added to the reactant of the second flask, the second flask was stirred at 70 ° C. for 5 hours. Thereafter, 3,3'-propyl-difuran is obtained by purifying the contents of the second flask.

After 3,3'-propyl-difuran is dissolved in THF, NBS (N-bromosuccimide) is added at room temperature and stirred at 55 ° C for 10 hours. After completion of the reaction, 2,2 ', 5,5'-tetrabromo-3,3'-propyl-difuran was obtained by column chromatography.

Synthesis of TTPF using 2,2 ', 5,5'-tetrabromo-3,3'-propyl-difuran was prepared using the same conditions and reactants as the synthesis of TTHT presented in Example 1. The same is true except that 2,2 ', 5,5'-tetrabromo-3,3'-propyl-difuran is used instead of 2,2', 5,5'-tetrabromo-3,3'-hexyl-dithiophene. TTPF is obtained, and the prepared TTPF is sublimed and purified under vacuum.

Example 3

Except for forming the electron transport layer 104 made of TiOx (1 <x <2) between the photoactive layer 103 and the second electrode 105 in the solar cell manufacturing process presented in Example 1 An organic solar cell is manufactured. The organic solar cell fabricated as described above had a Voc value of 0.68 V, a Jsc value of 17.2 mA / cm ² , a curve factor of 72%, and a photoelectric conversion efficiency of 8.4%.

Example 4

ZnO-electron transport layer 104 is formed between the photoactive layer 103 and the second electrode 105 in the solar cell manufacturing process shown in Example 2, except that PANI: CSA is used instead of PEDOT: PSS. The organic solar cell was prepared in the same manner. The organic solar cell manufactured as described above had a Voc value of 0.71 V, a Jsc value of 16.9 mA / cm ² , a curve factor of 71%, and a photoelectric conversion rate of 8.5%.

In the exemplary embodiment of the present invention, the substrate 100 of the organic solar cell may be positioned adjacent to the first electrode 101 but may be positioned adjacent to the second electrode 105. In this case, the substrate 100 may be made of a material that does not transmit light.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (11)

Heterocyclic compound represented by the following formula.

First and second electrodes facing each other; And
An organic solar cell positioned between the first electrode and the second electrode and including a photoactive layer comprising a compound of the following formula.

delete delete The method of claim 2,
The organic solar cell further comprises a hole transport layer between the photoactive layer and the first electrode having a higher work function than the second electrode. delete The method of claim 2,
The organic solar cell further comprises an electron transport layer between the photoactive layer and the second electrode having a lower work function than the first electrode. The method of claim 7, wherein
The electron transport layer is a metal oxide, ZnO-based nanoparticles, Doped-ZnO-based nanoparticles, SnO ₂ nanoparticles, ITO nanoparticles, TiO ₂ nanoparticles, TiOx (1 <x <2), Cs ₂ CO ₃ , Titanium (D An organic solar cell comprising one or more selected from the group consisting of isoproxide) bis (2,4-pentadionate). The method of claim 2,
The photoactive layer comprises an acceptor material,
The acceptor material is an organic solar cell comprising one or more selected from the group consisting of fullerene derivatives, perylene derivatives, ZnO, TiO ₂ , CdS, CdSe or ZnSe. The method of claim 2,
The photoactive layer comprises a donor material,
The donor material is phthalocyanine-based pigments, indigo, thioindigo-based pigments, melancyanine compounds, cyanine compounds, phenylene vinylene-based polymer derivatives, characterized in that consisting of at least one selected from the group consisting of thiophene-based polymer derivatives Organic solar cell. The method of claim 2,
The photoactive layer is an organic solar cell comprising 30 to 80% by weight of donor material, 10 to 65% by weight of acceptor material and 0.1 to 20% by weight of heterocyclic compound.

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