KR101125192B1 - Fullerene derivatives, organic photovoltaic cell including the derivatives, and organic TFT including the derivatives - Google Patents

Abstract

Provided is a fullerene derivative, an organic solar cell including the same, and an organic thin film transistor including the same. The fullerene derivative may be represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is substituted or unsubstituted selenophene, telurophen ( tellurophene), or thienothiophene, R ₂ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, n is an integer of 1 to 5.

Description

Fullerene derivatives, organic solar cells comprising the same, and organic thin film transistors comprising the same {Fullerene derivatives, organic photovoltaic cell including the derivatives, and organic TFT including the derivatives}

The present invention relates to an organic material, and more particularly, to a fullerene derivative, an organic solar cell including the same, and an organic transistor.

Organic solar cells are the next generation of low-carbon, environmentally friendly energy sources with significantly lower prices than silicon-based inorganic solar cells. Currently, the organic solar cell may be divided into an electron donor material polymer and an electron acceptor material, a fullerene derivative. However, compared with silicon solar cells, organic solar cells have difficulty in commercialization due to low efficiency. Currently, P3HT is used as an electron donor polymer of organic solar cells, and PCBM is used as an electron acceptor material, but it is not yet reached the commercialization value.

The problem to be solved by the present invention is to provide a fullerene derivative that can improve the efficiency of the organic solar cell and an organic solar cell having the same.

Another object of the present invention is to provide an organic field effect thin film transistor using a fullerene derivative.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the present invention to achieve the above object provides a fullerene derivative. The fullerene derivative may be represented by the following Chemical Formula 1.

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is substituted or unsubstituted selenophene, telurophen ( tellurophene), or thienothiophene, R ₂ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, n is an integer of 1 to 5.

The fullerene derivative may be a fullerene derivative represented by the following Chemical Formula 2 or the following Chemical Formula 3.

In Formula 2, M is Se or Te, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or 1 to 12 carbon atoms An individual substituted or unsubstituted alkyl group, n is an integer of 1 to 5, R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a cyan group, Or florin group.

In Formula 3, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms And n is an integer of 1 to 5, and R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group, cyan group, or fluorine group having 1 to 12 carbon atoms.

Another aspect of the present invention to achieve the above object provides an organic solar cell. The organic solar cell includes a first electrode positioned on a substrate, an organic active layer disposed on the first electrode and containing a fullerene derivative represented by Chemical Formula 1, and a second electrode positioned on the organic active layer. .

Another aspect of the present invention to achieve the above object provides a method of manufacturing an organic solar cell. First, a first electrode is formed on a substrate. An organic active layer containing a fullerene derivative represented by Chemical Formula 1 is formed on the first electrode. A second electrode is formed on the organic active layer.

Another aspect of the present invention to achieve the above object provides an organic thin film transistor. The organic thin film transistor is disposed on a substrate and includes an organic semiconductor layer containing a fullerene derivative represented by Chemical Formula 1, a gate electrode overlapping with the organic semiconductor layer on or below the organic semiconductor layer, and both sides of the organic semiconductor layer. A source electrode and a drain electrode are respectively connected to the ends.

According to the present invention, a fullerene derivative represented by Chemical Formula 1, that is, a fullerene derivative containing selenophene, tellurofen, or thienothiophene as a substituent was synthesized. The fullerene derivative exhibits properties that can replace the PCBM currently used.

Furthermore, the use of the fullerene derivative may form a film having improved charge transfer characteristics. Therefore, when the fullerene derivative is used as the organic active layer of the organic solar cell, current density and efficiency can be improved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

Formula 1 is a fullerene derivative according to an embodiment of the present invention.

[Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is substituted or unsubstituted selenophene, telurophen ( tellurophene), or thienothiophene, R ₂ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, n is an integer of 1 to 5.

R ₁ may be a selenophene, telurofen, or thienothiophene having 1 to 3 substituted or unsubstituted alkoxy, cyan, and fluorine groups having 1 to 12 carbon atoms. have. R ₂ may be a straight or branched alkyl group, for example CH ₂ CH (CH ₃ ) ₂ .

The fullerene derivative represented by Chemical Formula 1 may be used as an electron acceptor material of an organic solar cell or as a semiconductor material of an organic transistor.

Specific examples of the fullerene derivative may be as follows.

[Formula 2]

In Formula 2, M is Se or Te, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or 1 to 12 carbon atoms An individual substituted or unsubstituted alkyl group, n is an integer of 1 to 5, R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a cyan group, Or florin group. R ₂ may be a straight or branched alkyl group, for example, CH ₂ CH (CH ₃ ) ₂ .

(3)

In Formula 3, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms And n is an integer of 1 to 5, and R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group, cyan group, or fluorine group having 1 to 12 carbon atoms. R ₂ may be a straight or branched alkyl group, for example, CH ₂ CH (CH ₃ ) ₂ .

Scheme 1 below is a method for preparing a fullerene derivative according to an embodiment of the present invention.

Scheme 1

In Scheme 3, M is Se or Te, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or 1 to 12 carbon atoms An individual substituted or unsubstituted alkyl group, n is an integer of 1 to 5, R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a cyan group, Or florin group.

Referring to Scheme 1, compound (4), which is a selenophene derivative or a telurofen derivative, is reacted with an alkyl oxo-chloroalkanoate and Friedel Craft acylation reaction to give a compound (5). ) Can be obtained. The compound (5) was reacted with p-toluenesulfonyl hydrazide using a methylene chloride (MC) solution and reacted under reflux conditions to form a hydrazone-based compound ( 6) can be synthesized. After reacting the hydrazone compound (6) with pyridine and sodium methoxide, the fullerene derivative (2) is synthesized by dropwise reacting a fullerene (A) -dichlorobenzene solution thereto. can do.

Scheme 2 is another method for producing a fullerene derivative according to an embodiment of the present invention.

Scheme 2

In Scheme 3, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. And n is an integer of 1 to 5, and R _3a , R _3b , and R _3c are each independently hydrogen, a substituted or unsubstituted alkoxy group, cyan group, or fluorine group having 1 to 12 carbon atoms.

Referring to Scheme 2, compound (8) may be obtained by reacting compound (7), which is a thienothiophene derivative, with Friedel Crafts acylation with alkyl oxochloroalkanoate. The compound (8) can be synthesized by using a methylene chloride solution and reacting with paratoluenesulfonyl hydrazide under reflux conditions (9). After reacting the hydrazone-based compound (9) with pyridine and sodium methoxide, the fullerene derivative (3) can be synthesized by dropping the fullerene (A) -dichlorobenzene solution little by little.

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

Referring to FIG. 1, a first electrode 11, a first charge transport layer 13, an active layer 15, a second charge transport layer 17, and a second electrode 19 may be sequentially formed on the substrate 10. Can be.

The substrate 10 may be a transparent substrate. The transparent substrate may be a glass substrate or a plastic substrate. The first electrode 11 may be a transparent electrode and may also be a cathode. The first electrode 11 may be an indium tin oxide (ITO) film, an indium oxide (IO) film, a tin oxide (TO) film, a fluorinated tin oxide (FTO) film, an indium zinc oxide (IZO) film, or ZO (Znic). Oxide film).

The first charge transport layer 13 may be a hole transport layer. An example of the first charge transport layer 13 may be a PEDOT: PSS (poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) layer.

The organic active layer 15 is a layer that absorbs light to generate excitons, and may include a donor material and an acceptor material. The organic active layer 15 may be a bulk heterojunction (BHJ) layer in which a donor material and an acceptor material are mixed with each other. Alternatively, the organic active layer 15 may include a donor material layer and an acceptor material layer sequentially stacked.

The electron donor material is MEH-PPV (poly [2-methoxy-5- (2'-ethyl-hexyloxy) -1,4-phenylene vinylene]), MDMO-PPV (poly (2-methoxy-5- (3 ' It may be a PPV polymer such as, 7'-dimethyl-octyloxy))-p-phenylene vinylene) or a poly (3-hexylthiophene) polymer.

The electron acceptor material is a fullerene derivative represented by Chemical Formula 1. Since the fullerene derivative contains selenofene or telurophene having higher metallicity than benzene in the molecule, fullerene derivatives containing benzene, for example, have improved electron transfer characteristics compared to phenyl-C61-Butyric acid methyl ester (PCBM). Can be. In this case, the current density of the organic solar cell can be improved.

The organic active layer 15 may be formed by dissolving the donor material and the acceptor material in a solvent and then using a solution process. The solvent may be chlorobenzen or dichlorobenzene. When the organic active layer 15 is a bulk-heterojunction layer, the mixing concentration of the donor material and the acceptor material may have a mass ratio of 1: 0.5 to 1: 1.

The solution process may be a spin coating method, an ink-jet printing method, or a screen printing method. By forming the organic active layer 15 using the solution process, expensive vacuum equipment is not required, and thus the process cost can be reduced, and a large area solar cell can be realized.

The organic active layer 15 formed on the substrate may be heat treated. As a result, the organic active layer 15 may specifically improve the crystallinity of the electron donor material. The heat treatment may be performed at 110 ° C to 130 ° C, preferably 110 ° C.

The second charge transport layer 17 may be an exciton blocking layer that prevents diffusion of unexcited excitons. The exciton blocking layer may be a bathophen-anthroline (BPhen) layer.

The second electrode 19 may be a light reflecting electrode and may also be an anode. In detail, the second electrode 19 is a metal electrode having a lower work function than the first electrode 11. As an example, the second electrode 19 may be an Al film, a Ca film, or an Mg film. Preferably, the second electrode 19 may be a double layer of a Ca film, which is a metal having a low work function, and an Al film, which is a metal having excellent conductivity.

2A is a cross-sectional view illustrating an organic thin film transistor according to an embodiment of the present invention.

Referring to FIG. 2A, a buffer layer 21 may be formed on the substrate 20. The substrate 20 may be a silicon substrate, a glass substrate, or a polymer substrate. The buffer layer 21 may be a silicon oxide film or a silicon nitride film.

A gate electrode G may be formed on the substrate 20. The gate electrode G may be formed of aluminum, an aluminum alloy, molybdenum, or molybdenum alloy.

A gate insulating layer GI may be formed on the gate electrode G. The gate insulating layer GI may be formed of a single layer or a multilayer of an organic insulating layer or an inorganic insulating layer or may be an organic-inorganic hybrid layer. The inorganic insulating film may be a silicon oxide film, a silicon nitride film, Al2O3, Ta2O5, BST, or PZT, and the organic insulating film may be polymethacrylate (PMMA, polymethylmethacrylate), polystyrene (PS, polystyrene), parylene, PVP (Poly-4-vinylphenol), PVA (poly vinylalcohol), BCB (divinyltetramethyldisiloxane-bis (benzocyclobutene) (BCB), PαMS (Poly-Alpha-Methylstyrene), or PET (Poly ethylene Terephthalate).

The organic semiconductor layer (A) may be formed by coating the fullerene derivative represented by Chemical Formula 1 on a substrate by using a solution in which a solvent is dissolved in a solvent. The solvent may be chlorobenzene (chrolobenzene) or dichlorobenzene (dichrolobenzene). The solution process may be spin coating or inkjet printing. Therefore, since expensive vacuum equipment is not required in forming the film, the process cost can be lowered and it is suitable for manufacturing a large area device.

The organic semiconductor layer A may be heat treated.

In the organic thin film transistor, since the gate electrode is positioned under the organic semiconductor layer, and the source and drain electrodes are connected to the organic semiconductor layer, the organic thin film transistor of the present embodiment may be a bottom gate-top contact type thin film transistor.

2B is a cross-sectional view illustrating an organic thin film transistor according to another embodiment of the present invention. The organic thin film transistor according to the present exemplary embodiment may be substantially the same as the organic thin film transistor described with reference to FIG. 2A except as described below.

Referring to FIG. 2B, a buffer layer 21 may be formed on the substrate 20. A gate electrode G may be formed on the substrate 10. A gate insulating layer GI may be formed on the gate electrode G.

Source and drain electrodes S and D are spaced apart from each other on the gate insulating layer GI. The gate insulating layer GI may be exposed between the source and drain electrodes S and D.

An organic semiconductor layer A may be formed on the source and drain electrodes S and D and the gate insulating layer GI. The organic semiconductor layer (A) may be formed using the fullerene derivative represented by Chemical Formula 1.

In the organic thin film transistor, since the gate electrode is positioned below the organic semiconductor layer, and the source and drain electrodes are connected to the lower surface of the organic semiconductor layer, the organic thin film transistor of the present embodiment may be a bottom gate-bottom contact type thin film transistor. have.

2C is a cross-sectional view illustrating an organic thin film transistor according to another embodiment of the present invention. The organic thin film transistor according to the present exemplary embodiment may be substantially the same as the organic thin film transistor described with reference to FIG. 2A except as described below.

Referring to FIG. 2C, a buffer layer 21 may be formed on the substrate 20. Source and drain electrodes S and D may be formed on the buffer layer 11. The buffer layer 11 may be exposed between the source and drain electrodes S and D.

An organic semiconductor layer A may be formed on the source and drain electrodes S and D and the buffer layer 11 exposed therebetween. The organic semiconductor layer (A) may be formed using the fullerene derivative represented by Chemical Formula 1. A gate insulating layer GI may be formed on the organic semiconductor layer A. FIG. A gate electrode G may be formed on the gate insulating layer GI.

In the organic thin film transistor, since the gate electrode is positioned above the organic semiconductor layer, and the source and drain electrodes are connected to the lower surface of the organic semiconductor layer, the organic thin film transistor of the present embodiment may be a top gate-bottom contact type thin film transistor. .

Next, a preferable experimental example is provided to help understanding of the present invention. However, the following experimental example is for illustrating the present invention and does not limit the content of the present invention.

Synthesis Example 1 SeCBM Synthesis

Selenophene and methyl 5-oxochloropentanoate (methyl 5-oxochloropentanoate, 5-methyl-2-chloroxavalerate) were subjected to Friedel Crafts acylation reaction to obtain compound (5a). Hydrazone-based compound (6a) was synthesized by refluxing compound (5a) in a methylene chloride solution using paratoluenesulfonyl hydrazide for 12 hours. After continuously reacting Compound (6a) with 10 mL of pyridine and sodium methoxide for about 30 minutes, the reaction was carried out for 12 hours while dropping a dichlorobenzene solution in which C ₆₀ phosphorus fuller was dissolved. After completion of the reaction, the reaction product was purified using a silica column (developing solvent: toluene) to obtain compound (2a), that is, SeCBM (Selenyl-C61-butyric acid methyl ester). Compound (2a) was put back into a micro-tube (micro-tube) to obtain a precipitate by centrifugation at 15000 rpm, and dried at 70 to 24 hours. This was dissolved in chloroform-d solvent and subjected to structural analysis by ¹ H-NMR.

Synthesis Example 2 TThCBM Synthesis

Thienothiophene and methyl 5-oxochloropentanoate (methyl 5-oxochloropentanoate, 5-methyl-2-chloroxavalerate) were subjected to Friedel Crafts acylation reaction to obtain Compound (8a). Hydrazone-based compound (9a) was synthesized by refluxing compound (8a) with paratoluenesulfonyl hydrazide in methylene chloride solution for 12 hours. After continuously reacting Compound (9a) with 10 mL of pyridine and sodium methoxide for about 30 minutes, the reaction was carried out for 12 hours while dropping a dichloro benzene solution in which C ₆₀ phosphorus fuller was dissolved. After the reaction was completed, the reaction product was purified using a silica column (developing solvent: toluene) to obtain compound 3a, that is, thienothienyl-C61-butyric acid methyl ester (TThCBM). Compound (3a) was put back into the micro-tube (micro-tube) to obtain a precipitate by centrifugation at 15000 rpm, and dried at 70 to 24 hours. This was dissolved in chloroform-d solvent and subjected to structural analysis by ¹ H-NMR.

Analytical Example 1: Electrochemical Properties of Fullerene Derivatives

SeCBM according to Synthesis Example 1, TThCBM or Synthesis PCB 2 according to Synthesis Example 2 were dissolved in chlorobenzene solvent to make 0.5 wt% solution, spin-coated on the working electrode ITO substrate, and Ag / AgCl was installed as a reference electrode. Then, 0.1M tetrabutylammonium perchlorate-acetonitrile (CH ₃ CN) electrolyte solution was added between these two electrodes, and the cyclic voltammetry was obtained using cyclic voltammetry.

5 is a cyclic voltage current curve for SeCBM according to Synthesis Example 1, TThCBM according to Synthesis Example 2, and PCBM.

Specifically, referring to FIG. 5, SeCBM, TThCBM, and PCBM have measured onset potentials of −0.14 V, −0.14 V, and −0.22 V, respectively. From this, the LUMOs of SeCBM, TThCBM and PCBM were calculated to be 4.24 eV, 4.24 eV, and 4.16 eV, respectively.

Comparative Example 1: Manufacture of Organic Solar Cell (P3HT: PCBB (DCB))

PEDOT: PSS was spin-coated at a speed of 4000 rpm for 40 seconds on ITO (Indium Tin Oxide), which is a transparent electrode substrate, and then dried at 110 ° C. for 10 minutes. P3HT (poly [3-hexylthiophene]) and PCBM (Phenyl-C61-Butyric acid methyl ester) were dissolved in dichlorobenzene at 0.8 wt%, respectively, and the two solutions were mixed and stirred for 12 hours to obtain an active layer solution. The active layer solution was spin-coated on the PEDOT: PSS layer at a speed of 1200 rpm for 40 seconds, then placed in a Petri dish for 30 minutes, and dried at 110 ° C. for 10 minutes to form an active layer. Calcium and aluminum were thermally deposited on the active layer at a high vacuum of 10 ⁻⁶ Torr, respectively, to form a calcium layer of about 20 nm and an aluminum layer of about 100 nm.

Comparative Example 2: Preparation of Organic Solar Cell (P3HT: PCBB (CB))

PEDOT: PSS was spin-coated at a speed of 4000 rpm for 40 seconds on ITO (Indium Tin Oxide), which is a transparent electrode substrate, and then dried at 110 to 10 minutes. P3HT (poly [3-hexylthiophene]) and PCBM (Phenyl-C61-Butyric acid methyl ester) were dissolved in chlorobenzene at 0.8 wt%, respectively, and the two solutions were mixed and stirred for 12 hours to obtain an active layer solution. The active layer solution was spin coated on the PEDOT: PSS layer at a speed of 2000 rpm for 40 seconds and then dried at 110 for 10 minutes to form an active layer. Calcium and aluminum were thermally deposited on the active layer at a high vacuum of 10 ⁻⁶ Torr, respectively, to form a calcium layer of about 20 nm and an aluminum layer of about 100 nm.

Preparation Example 1: Fabrication of Organic Solar Cell (P3HT: SeCBM (DCB))

An organic solar cell was manufactured in the same manner as in Comparative Example 1, except that SeCBM synthesized through Synthesis Example 1 was used instead of PCBM.

Preparation Example 2 Preparation of Organic Solar Cell (P3HT: TThCBM (CB))

An organic solar cell was manufactured in the same manner as in Comparative Example 2, except that TThCBM synthesized through Synthesis Example 2 was used instead of PCBM.

Analysis Example 2 Analysis of Optical Properties of Active Layer

Figure 6a is a graph showing the UV-vis spectra of the active layers obtained through Preparation Example 1 and Comparative Example 1, Figure 6b is a graph showing the UV-vis spectra of the active layers obtained through Preparation Example 2 and Comparative Example 2.

6A and 6B, it can be seen that the maximum absorption wavelength bands of the active layers obtained through Preparation Example 1 and Comparative Example 1 are almost the same, and the maximum absorption wavelength bands of the active layers obtained through Preparation Example 2 and Comparative Example 2 are almost the same. Can be. However, in the case of the active layer containing TThCBM, the absorbance was found to decrease a little in the 320nm to 350nm portion compared to the active layer containing the PCBM. The reason for this is that TThCBM has low solubility, so that a filter part occurs when measuring absorbance.

Analysis Example 3: Surface Analysis of Active Layer

7A shows AFM images before and after heat treatment of active layers obtained through Preparation Example 1 and Comparative Example 1. FIG. 7B shows AFM images before and after heat treatment of the active layers obtained through Preparation Example 2 and Comparative Example 2. FIG.

Referring to FIGS. 7A and 7B, when the SeCBM (Preparation Example 1) was applied instead of the PCBM (Comparative Example 1), the surface roughness was almost similar. However, when TThCBM (Preparation Example 2) was applied instead of PCBM (Comparative Example 2), the surface roughness was increased, which was presumably due to the low solubility of TThCBM that did not form nano-scale morphology.

Analysis Example 4: Characteristics of Organic Solar Cell

FIG. 8A is a graph showing current densities of voltages of organic solar cells manufactured through Preparation Example 1 and Comparative Example 1, and FIG. 8B illustrates current versus voltage of organic solar cells manufactured through Preparation Example 2 and Comparative Example 2. It is a graph showing the density.

Open circuit voltage (Voc), Short Circuit Current Density (Jsc) of each of the organic solar cells of Preparation Examples 1 and 2 and Comparative Examples 1 and 2 using the data shown in the graphs. ), And a fill factor (FF) were extracted, and a power conversion efficiency (PCE) was calculated using an input power density (Ps) of 100 mW / cm ² and is shown in Table 1 below.

TABLE 1

Active layer Jsc
(mA / cm ² ) Voc
(V) FF
(%) Efficiency
(%) Preparation Example 1 P3HT: SeCBM (DCB) 10.70 0.58 68 4.22 Comparative Example 1 P3HT: PCBM (DCB) 9.94 0.60 68 4.00 Production Example 2 P3HT: TThCBM (CB) 7.23 0.55 55 2.19 2 in comparison P3HT: PCBM (CB) 8.36 0.65 65 3.53

8A, 8B, and Table 1, it can be seen that in the case of Preparation Example 1 compared with Comparative Example 1, the current density Jsc was increased, and the overall efficiency was increased. This increase in current density is presumably because selenofene has a metallic characteristic and excellent charge mobility. In particular, although the open voltage (Jsc) was reduced by 0.02 V, the overall efficiency was increased compared to Comparative Example 1 due to the improved current density and fill factor (FF) of Preparation Example 1. The enhancement of the fill factor (FF) is due to the interaction between the larger and more polar elements of selenium and the polar elements of P3HT which are polar in P3HT, resulting in uniform nanometer-sized film morphology in films of electron donor and electron acceptor materials. Is probably due to the formation of

However, in Preparation Example 2, it showed lower open voltage (Voc) and current density (Jsc) than in Comparative Example 2 because the low solubility of TThCBM was estimated to be due to the failure to form a nano-scale morphology.

Preparation Example 3 Preparation of Organic Field Effect Transistor (SeCBM)

An organic field effect transistor as shown in FIG. 9 was prepared. Specifically, an n-type silicon wafer was used as the substrate. The substrate serves as a gate electrode (G). A silicon oxide film as a gate insulating film GI was thermally grown on the gate electrode G to a thickness of 300 nm. SeCBM synthesized according to Preparation Example 1 was dissolved in a DCB (o-Dichlorobenzene) solvent to form a 1 wt% solution, and the solution was spin-coated at 1500 rpm on the gate insulating film GI to form an organic semiconductor layer having a thickness of 45 nm (A ) Was formed. The organic semiconductor layer (A) was heat treated at 110 ° C. for 20 minutes.

Gold was deposited on the organic semiconductor layer A to form a source electrode S and a drain electrode D having a thickness of 30 nm.

Comparative Example 3 Preparation of Organic Field Effect Transistor (PCBM)

An organic solar cell was manufactured in the same manner as in Preparation Example 3, except that PCBM was used instead of SeCBM as the organic semiconductor layer.

Analysis Example 5: Characteristics of Organic Field Effect Transistor

10A and 10B are transfer curves and output curves of the organic field effect transistors prepared in Preparation Example 3, respectively. FIGS. 11A and 11B are transfer curves and output curves of the organic field effect transistors prepared in Comparative Example 3, respectively. to be.

10A, 10B, 11A, and 11B, the threshold voltage and the charge mobility of the organic field effect transistor manufactured according to Preparation Example 3 are about 11.5V and about 0.04 cm ² / Vs, respectively, and Comparative Examples Threshold voltage and charge mobility of the organic field effect transistor prepared according to 3 were calculated to be about 8.9V and about 0.04 cm ² / Vs, respectively.

While the invention has been described above with reference to specific preferred embodiments, it is intended that the specific modifications and variations of the invention fall within the scope of the invention and the specific scope of the invention will be apparent from the appended claims.

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

2A is a cross-sectional view illustrating an organic field effect transistor according to an embodiment of the present invention.

2B is a cross-sectional view illustrating an organic field effect transistor according to another embodiment of the present invention.

2C is a cross-sectional view illustrating an organic field effect transistor according to another embodiment of the present invention.

3 is a graph showing ¹ H-NMR of SeCBM obtained through Synthesis Example 1. FIG.

4 is a graph showing ¹ H-NMR of TThCBM obtained through Synthesis Example 2. FIG.

5 is a cyclic voltage current curve for SeCBM according to Synthesis Example 1, TThCBM according to Synthesis Example 2, and PCBM.

6A is a graph showing UV-vis spectra of active layers obtained through Preparation Example 1 and Comparative Example 1, and FIG. 6B is a graph showing UV-vis spectra of active layers obtained through Preparation Example 2 and Comparative Example 2. FIG.

7A shows AFM images before and after heat treatment of active layers obtained through Preparation Example 1 and Comparative Example 1. FIG. 7B shows AFM images before and after heat treatment of the active layers obtained through Preparation Example 2 and Comparative Example 2. FIG.

FIG. 8A is a graph showing current densities of voltages of organic solar cells manufactured through Preparation Example 1 and Comparative Example 1, and FIG. 8B illustrates current versus voltage of organic solar cells manufactured through Preparation Example 2 and Comparative Example 2. It is a graph showing the density.

11 is a cross-sectional view showing an organic field effect transistor according to Preparation Example 3. FIG.

10A and 10B are transfer curves and output curves of the organic field effect transistors prepared according to Preparation Example 3, respectively.

11A and 11B are transfer curves and output curves of the organic field effect transistors prepared in Comparative Example 3, respectively.

Claims (17)

Fullerene derivative represented by the following formula (1): [Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is selenophene, tellurophene, or cy It is a thienothiophene, R <_2> is hydrogen or an alkyl group of 1-12 carbon atoms, n is an integer of 1-5. The method of claim 1, The R ₁ is a fullerene derivative of any one or a plurality of substituted alkoxy, cyan, and fluorine groups having 1 to 3 carbon atoms, selenophene, telurophene, or thienothiophene. The method of claim 1, The fullerene derivative is a fullerene derivative represented by Formula 2 below: [Formula 2]

In Formula 2, M is Se or Te, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or 1 to 12 carbon atoms It is a personal alkyl group, n is an integer of 1-5, R <_3a> , R <_3b> , and R <_3c> are hydrogen, the C1-C12 alkoxy group, a cyan group, or a fluorine group irrespective of each other. The method of claim 1, The fullerene derivative is a fullerene derivative represented by Formula 3 below: (3)

In Formula 3, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or an alkyl group having 1 to 12 carbon atoms, n is 1 It is an integer of -5, and R <_3a> , R <_3b> , and R <_3c> are hydrogen, the alkoxy group of 1 to 12 carbon atoms, a cyan group, or a florin group irrespective of each other. A first electrode on the substrate; An organic active layer disposed on the first electrode and containing a fullerene derivative represented by Formula 1 below; And An organic solar cell comprising a second electrode on the organic active layer: [Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is selenophene, R ₂ is hydrogen or 1 carbon And an alkyl group of 12 to 12, n is an integer of 1 to 5. The method of claim 5, The fullerene derivative is an organic solar cell represented by Formula 2 below:  [Formula 2]

In Formula 2, M is Se, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or an alkyl group having 1 to 12 carbon atoms And n is an integer of 1 to 5, and R _3a , R _3b , and R _3c are each independently hydrogen, an alkoxy group having 1 to 12 carbon atoms, a cyan group, or a fluorine group. delete The method of claim 5, The fullerene derivative is an electron acceptor material, and the organic active layer further contains an electron donor material. The method of claim 8, The electron donor material is an organic solar cell of PPV (poly (phenylene vinylene)) polymer or P3HT (poly (3-hexylthiophene)) polymer. The method of claim 8, The organic active layer is an organic solar cell is a bulk-heterojunction layer is a mixture of donor material and acceptor material. The method of claim 5, An organic solar cell further comprising a first charge transport layer located between the first electrode and the organic active layer or a second charge transport layer located between the organic active layer and the second electrode. Forming a first electrode on the substrate; Forming an organic active layer containing a fullerene derivative represented by Chemical Formula 1 below on the first electrode; And An organic solar cell manufacturing method comprising the step of forming a second electrode on the organic active layer: [Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is selenophene, R ₂ is hydrogen or 1 carbon And an alkyl group of 12 to 12, n is an integer of 1 to 5. The method of claim 12, The organic active layer is formed by coating a solution in which the fullerene derivative is dissolved in a solvent on the first electrode. The method of claim 12, An organic solar cell manufacturing method further comprising the step of heat-treating the organic active layer. An organic semiconductor layer located on a substrate and containing a fullerene derivative represented by Formula 1 below;  A gate electrode overlapping the organic semiconductor layer on or below the organic semiconductor layer; And An organic thin film transistor comprising a source electrode and a drain electrode respectively connected to both ends of the organic semiconductor layer; [Formula 1]

In Formula 1, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₁ is selenophene or tellurophene, R is ₂ is hydrogen or an alkyl group having 1 to 12 carbon atoms, and n is an integer of 1 to 5; The method of claim 15, The fullerene derivative is an organic thin film transistor represented by Formula 2 below:  [Formula 2]

In Formula 2, M is Se or Te, A is C ₆₀ , C ₇₀ , C ₇₂ , C ₇₆ , C ₇₈ , C ₈₄ , or C ₉₀ fullerene, R ₂ is hydrogen, or 1 to 12 carbon atoms It is a personal alkyl group, n is an integer of 1-5, R <_3a> , R <_3b> , and R <_3c> are hydrogen, the C1-C12 alkoxy group, a cyan group, or a fluorine group irrespective of each other. delete

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