KR101072477B1 - Organic semiconductor compounds substituted alkylthiophen group in side-chain of polymer and organic thin film transistor utilizing same - Google Patents

Abstract

The present invention relates to an organic semiconductor compound for organic thin film transistor (OTFT) and its use. More specifically, the present invention improves the solubility of a polymer material by introducing a thiophene group substituted with an alkyl group into the side chain of the polymer organic semiconductor compound used as the semiconductor layer material of the organic thin film transistor by repulsion of the main chain and the side chain. While conjugation with the side chain is maintained, the present invention relates to an organic semiconductor compound having a new structure and its use.

Description

Organic semiconductor compounds substituted alkylthiophen group in side-chain of polymer and organic thin film transistor utilizing same}

The present invention relates to an organic semiconductor compound for organic thin film transistor (OTFT) and its use. More specifically, the present invention improves the solubility of a polymer material by introducing a thiophene group substituted with an alkyl group into the side chain of the polymer organic semiconductor compound used as the semiconductor layer material of the organic thin film transistor by repulsion of the main chain and the side chain. While conjugation with the side chain is maintained, the present invention relates to an organic semiconductor compound having a new structure and its use.

The development of telecommunications in the 21st century and the desire for personal handheld communication devices are high performance electricity that can produce ultra-fine processing and ultra-high integrated circuits that enable small and light, thin and easy-to-use information and communication devices. There is a need for new information and communication materials that enable the display of electronic materials and new concepts. Among them, organic thin film transistors (OTFTs) are used for display drivers such as portable computers, organic EL devices, smart cards, electric tags, pagers, mobile phones, and memory devices such as cash machines and identification tags. The possibility of being used as an important component of plastic circuitry has been the subject of much research.

The organic thin film transistor using the organic semiconductor has the advantages of simpler manufacturing process and lower cost production compared to the organic thin film transistor using amorphous silicon and polysilicon, and is compatible with the plastic substrates for implementing the flexible display. Due to this superior advantage, many researches are being made recently. In particular, when the polymer organic semiconductor is used, the manufacturing cost can be reduced compared to the low molecular organic semiconductor compound because of the advantage that the thin film can be easily formed by the solution process.

Representative semiconductor compounds for polymer-based organic thin film transistors developed to date include P3HT [poly (3-hexylthiophene)] and F8T2 [poly (9,9-dioctylfluorene-co-bithiophene)]. There are many performances of OTFT, but the most important evaluation scale is charge mobility and on / off ratio, and the most important evaluation scale is charge mobility. The charge mobility varies depending on the type of semiconductor material, thin film formation method (structure and morphology), driving voltage, and the like.

1 is a cross-sectional view showing the structure of a general organic thin film transistor composed of a substrate / gate / insulation layer / electrode layer (source, drain) / organic semiconductor layer. In the figure, a gate electrode is formed on the substrate. An insulating layer is formed on the gate electrode, and an organic semiconductor layer, and a source and a drain electrode are sequentially formed on the gate electrode. The driving principle of the organic thin film transistor having the above structure will be described below with an example of a p-type semiconductor. First, when a current is applied by applying a voltage between the source and the drain, a current proportional to the voltage flows under a low voltage. When a positive voltage is applied to the gate, holes that are positive charges are all pushed up to the top of the semiconductor layer by the electric field by the applied voltage. Thus, the portion close to the insulating layer will have a depletion layer without conduction charge, and in such a situation, a low amount of current will flow due to the reduced number of conducting charge carriers even when a voltage is applied between the source and the drain. . On the contrary, when a negative voltage is applied to the gate, an accumulation layer in which positive charges are induced near the insulating layer is formed by the effect of the electric field caused by the applied voltage. At this time, since there are many conducting charge carriers between the source and the drain, more current can flow. Therefore, the current flowing between the source and the drain can be controlled by alternately applying a positive voltage and a negative voltage to the gate while a voltage is applied between the source and the drain.

The organic thin film transistors, which are constructed on the principle described above, include electrodes (source and drain), substrates and gate electrodes requiring high thermal stability, insulators having high dielectric properties and dielectric constants, and semiconductors that transfer charges well. There are many problems to overcome, and the core material is an organic semiconductor. Organic semiconductors may be classified into low molecular organic semiconductors and high molecular organic semiconductors according to molecular weight, and classified into n-type organic semiconductors or p-type organic semiconductors depending on whether electrons or holes are transferred. In general, when a low molecular weight organic semiconductor is used to form an organic semiconductor layer, the low molecular weight organic semiconductor is easy to purify and almost removes impurities, and thus has excellent charge transfer characteristics. However, such an organic semiconductor cannot be spin coated and printed. Therefore, since the thin film must be manufactured by vacuum deposition, the manufacturing process is complicated and expensive compared with the polymer organic semiconductor. In the case of the polymer organic semiconductor, it is difficult to purify the high purity, but excellent heat resistance, spin coating and printing is possible, there is an advantage in the manufacturing process, cost, mass production.

Although many studies have been made to date for the development of organic semiconductor materials, the development of polymer semiconductor materials is still far from the development of low molecular weight semiconductor materials. Therefore, in order to develop an electronic device using a flexible, low-cost organic thin film transistor, it is urgent to develop a polymer semiconductor material. Generally, charge mobility of polymer is known to be inferior to low molecule, but it can be said to be a material that can sufficiently overcome this in manufacturing process and cost. In order to realize flexible display in the future, polymer semiconductor material must be developed first Should be.

An object of the present invention is to provide a novel organic semiconductor material for organic thin film transistors having high solubility and thermal stability, and having excellent alignment between polymer chains due to the liquid crystallinity of the polymer.

In addition, an object of the present invention is to improve the characteristics of the organic semiconductor compounds for organic thin film transistors developed to date by introducing a thiophene group substituted with an alkyl group in the side chain of the polymer.

In addition, an object of the present invention is to provide a new type of organic semiconductor compound for organic thin film transistor and a synthesis method thereof which have not been developed so far.

Moreover, an object of this invention is to provide the organic thin film transistor which uses the organic semiconductor compound which concerns on this invention as an organic semiconductor layer.

The present invention relates to an organic semiconductor compound for organic thin film transistor (OTFT) and its use. More specifically, the present invention relates to an organic semiconductor compound having a novel structure in which a thiophene group substituted with an alkyl group is introduced into a side chain of a polymer organic semiconductor compound used as a semiconductor layer material of an organic thin film transistor and its use.

Hereinafter, the present invention will be described in detail.

[화학식 B]The organic semiconductor compound according to the present invention is a polymer having a conjugation structure in which one or more thiophene derivatives selected from Formulas (A) and (B) are substituted with side chains, and the solubility of the polymer material by repulsion of the main chain and the side chains. The organic semiconductor compound of the novel structure is maintained while conjugation with the side chain is maintained.
[Formula A]

[Formula B]

[Wherein R is (C1-C30) alkyl, a is an integer of 0 to 10, and b is an integer of 1 to 10.]

The polymer having the conjugation structure may be polyphenylene; Polyphenylenevinylene, polyaniline, polypyrrole, polythiophene, polyacetylene, poly (1,4-phenylenevinylene), poly (thienylene-vinylene), poly (3-alkyl-thiophene), polyphenyl It is selected from the group consisting of rensulfide, polyazulene, polyfuran and polyisothionaphthene, preferably polythiophene.

The organic semiconductor compound according to the present invention is most preferably represented by the following formula (1).

[Formula 1]

[Ar ₃ is a chemical bond or (C3-C30) heteroarylene; R ₁ and R ₂ are independently of each other (C1-C30) alkyl; n is an integer from 1 to 100,000.]

The organic semiconductor compound according to the present invention is specifically selected from the compounds represented by the following formulas (2) and (3).
(2)

(3)

[n is an integer from 1 to 100,000].

As a method for preparing an organic semiconductor compound according to the present invention, the final compound may be prepared through an alkylation reaction, a green nyd coupling reaction, a Suzuki coupling reaction, or the like. The organic semiconductor compound according to the present invention is not limited to the above production method, and may be prepared by a conventional organic chemical reaction in addition to the above production method.

The organic semiconductor compound according to the present invention may be used as a material for forming an organic semiconductor layer of an organic thin film transistor, and specific examples of the method of manufacturing the organic thin film transistor using the same are as follows.

As the substrate 11, it is preferable to use n-type silicon used in a conventional organic thin film transistor. This substrate contains the function of the gate electrode. In addition to n-type silicon, a glass substrate or a transparent plastic substrate having excellent surface smoothness, ease of handling, and waterproofness may be used as the substrate. In this case, a gate electrode must be added on the substrate. Substances which can be employed as the substrate include glass, polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVP), polyacrylate (Polyacrylate). , Polyimide, polynorbornene and polyethersulfone (PES).

An insulated gate constituting the OTFT device layer 12, as can be used with a large dielectric constant insulators conventionally used, specifically _{Ba 0 .33 Sr 0 .66 TiO 3} (BST), Al 2 O 3, Ta 2 O _{5, La 2 O 5, Y} 2 O 3 and a ferroelectric insulator, PdZr _{0 .33} selected from the group consisting of _{TiO 2 Ti 0 .66 O 3 (} PZT), Bi 4 Ti 3 O 12, BaMgF 4, SrBi 2 (TaNb ) ₂ O ₉ , Ba (ZrTi) O ₃ (BZT), BaTiO ₃ , SrTiO ₃ , Bi ₄ Ti ₃ O ₁₂ , SiO ₂ , SiN _x and AlON, an inorganic insulator selected from the group consisting of polyimide, Organic precursors such as benzocyclobutene (BCB), parylene, polyacrylate, polyvinylalcohol, and polyvinylphenol may be used.

As shown in FIG. 1, the organic thin film transistor of the present invention is composed of the substrate 11, the gate electrode 16, the insulating layer 12, the organic semiconductor layer 13, the source 14, and the drain electrode 15. As shown in FIG. It includes both top-contact as well as bottom-contact types of substrate / gate electrode / insulation layer / source and drain electrode / organic semiconductor layer. In addition, HMDS (1,1,1,3,3,3-hexamethyldisilazane), OTS (octadecyltrichlorosilane) or OTDS (octadecyltrichlorosilane) may be used as a surface treatment between the source 14 and the drain electrode 15 and the organic semiconductor layer 13. It may or may not be coated.

The organic semiconductor layer employing the organic semiconductor compound according to the present invention may be formed into a thin film by vacuum deposition, screen printing, printing, spin casting, spin coating, dipping or ink spraying, Deposition of the organic semiconductor layer may be formed using a high temperature solution at 40 ℃ or more, the thickness is preferably about 500 kPa.

The gate electrode 16 and the source and drain electrodes 14 and 15 may be conductive materials, but gold (Au), silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr), and indium tin may be used. It is preferably formed of a material selected from the group consisting of oxides (ITOs).

A polymer having a conjugation structure in which a thiophene group substituted with an alkyl group is introduced into a side chain of an organic semiconductor compound according to the present invention, ie, a polymer organic semiconductor compound used as a semiconductor layer material of an organic thin film transistor, has a side chain of a polymer having a conjugation structure. The introduction of a thiophene group substituted with an alkyl group to the main chain and side chains has the property of maintaining the conjugation with the side chains while improving the solubility of the polymer material by repulsion. In addition, the HOMO value decreases, that is, the electron density increases in the repeating unit, thereby having excellent charge mobility and oxidation stability, and thus may be used as an organic semiconductor layer of the organic thin film transistor. Therefore, when using organic thin film transistors employing these, it is possible to make electronic devices having excellent efficiency and performance. The organic thin film transistor can also be manufactured by a solution process such as vacuum deposition, spin coating, or printing, thereby reducing the manufacturing cost of an electronic device using the organic thin film transistor.

Fig. 1-A cross-sectional view showing the structure of a general organic thin film transistor made of a substrate / gate / insulating layer (source, drain) / semiconductor layer.
2-Curves showing the thermal properties of the organic semiconductor compounds (PDTQT and PDTST) according to Examples 1 and 2
3-UV-vis absorption and PL spectra of the solution phase and the film phase of the organic semiconductor compound (PDTQT) according to Example 1
4-UV-vis absorption and PL spectra of the solution phase and the film phase of the organic semiconductor compound (PDTST) according to Example 2
5 shows an out-of-plane GIXD image of a device fabricated by the method of Example 3 using the organic semiconductor compounds PDTQT and PDTST according to Examples 1 and 2.
6-AFM images (a: film state of PDTST, b: film state of PDTQT) of the device manufactured by the method of Example 3 using the organic semiconductor compounds (PDTQT and PDTST) according to Example 1 and Example 2, c: film state of PDTST annealed at 100 ° C., d) film state of PDTST annealed at 100 ° C.)
7-Organic semiconductor characteristics (a: PDTST transfer curve, b: PDTQT transfer curve) of the organic semiconductor compound (PDTQT and PDTST) according to Example 3 using the organic semiconductor compounds according to Example 1 and Example 2 , c: output curve of PDTST, d: TOF of PDTST)
8-Stability of a semiconductor device fabricated by the method of Example 3 using the organic semiconductor compounds (PDTQT and PDTST) according to Examples 1 and 2 (a: PDTST atmospheric stability, b: atmospheric stability of PDTQT, c : P3HT atmospheric stability, d: charge mobility and flashing ratio of PDTST over time)

The present invention can be more clearly understood by the following examples, which are only intended to illustrate the present invention and are not intended to limit the scope of the invention.

Preparation Example 1 Synthesis of 5-decyl-2,3'-bithiophene (5-decyl-2,3'-bithiophene)

Slowly add 2-bromo-5-decylthiophene (20.5 g, 67.47 mmol) to magnesium (1.6 g, 67.47 mmol) and diethylether (100 mL) to make a Grignard reagent, followed by 3-bromothiophene ( 10.0 g, 61.33 mmol) and Pd (dppf) Cl ₂ (0.5g, 0.61 mmol) and diethyl ether (160 mL) are added slowly to the mixture. After reacting at room temperature for 24 hours, the mixture was extracted with diethyl ether and then filtered with MgSO ₄ . After the solvent was removed, the residue was purified by column chromatography using hexane to obtain 5-decyl-2,3'-bithiophene as a target compound. Yield: (13.0 g, 72%). _{^{1 HNMR (CDCl 3, 300 MHz}} ) [ppm]: δ 7.38-7.33 (m, 3H), 7.07 (d, J = 3.5Hz, 1H), 6.77 (d, J = 3.5 Hz, 1H), 2.88 (t , J = 7.5 Hz, 2H), 1.83-1.73 (m, 2H), 1.42-1.38 (m, 14H), 1.00 (t, J = 6.3 Hz, 3H).

Preparation Example 2 Synthesis of 2'-bromo-5-decyl-2,3'-bithiophene (2'-bromo-5-decyl-2,3'-bithiophene)

5-decyl-2,3'-bithiophene (Preparation Example 1, 5.0 g, 16.31 mmol) was dissolved in a mixed solution of CHCl ₃ / CH ₃ COOH (1/1, 100 mL), followed by NBS (2.9 at 0 ° C). g, 16.31 mmol) was added slowly. After slowly raising to room temperature and stirred for 6 hours. Extract with diethyl ether and wash with NaOH (0.1 M, 3 x 200 mL) and water (3 x 200 mL). The solvent was removed to obtain 2'-bromo-5-decyl-2,3'-bithiophene as the target compound. Yield: (5.9 g, 94%) ¹ H-NMR (CDCl ₃ , 300 MHz) [ppm]: δ 7.32 (d, J = 3.6 Hz, 1H), 7.26 (d, J = 5.7 Hz, 1H), 7.13 (d, J = 5.7 Hz, 1H), 6.8 (d, J = 3.6Hz, 1H), 2.86 (t, J = 7.5Hz, 2H), 1.77-1.72 (m, 2H), 1.42-1.32 (m, 14H), 0.94 (t, J = 6.3 Hz, 3H).

Preparation Example 3 3- (5-decylthiophen-2-yl) -2- (5- (5- (3- (5-decylthiophen-2-yl) thiophen-2-yl) thiophene -2-yl) thiophen-2-yl) thiophene (3- (5-Decylthiophene-2-yl) -2- (5- (5- (3- (5-decylthiophene-2-yl) thiophene-2 -yl) thiophene-2-yl) thiophene-2-yl) thiophene (DDT)

2'-bromo-5-decyl-2,3'-bithiophene (Preparation Example 2, 6.5 g, 16.86 mmol) and 5,5'-bis (tributylstannyl) -2,2'-biti Offen (3.32 mL, 6.75 mmol) is dissolved in toluene. Pd (PPh ₃ ) ₄ (0.23 g, 0.2 mmol) is added and stirred at 100 ° C. for 24 h. Extracted with methylene dichloride and purified by column chromatography using hexane to obtain the target compound 3- (5-decylthiophen-2-yl) -2- (5- (5- (3- (5-de) Silthiophen-2-yl) thiophen-2-yl) thiophen-2-yl) thiophen-2-yl) thiophene (DDT) was obtained. Yield: 2.3 g, 49% ¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): aromatic (CH), 7.287.25 (m, 2H), 7.157.13 (d, 2H), 7.057.02 ( m, 4H), 6.926.91 (d, 2H), 6.706.69 (d, 2H), aliphatic (CH) 2.832.78 (t, 4H), 1.721.63 (m, 4H), 1.371.27 (m , 28H), 0.910.87 (t, 6H).

Preparation Example 4 5-Bromo-2- (5- (5- (5-bromo-3- (5-decylthiophen-2-yl) thiophen-2-yl) thiophen-2-yl ) Thiophen-2-yl) -3- (5-decylthiophen-2-yl) thiophene (5-Bromo-2- (5- (5- (5-bromo-3- (5-decylthiophene-2-2) Synthesis of -yl) thiophene-2-yl) thiophene-2-yl) thiophene-2-yl) -3- (5-decylthiophene-2-yl) thiophene; BDDT

DDT (Preparation Example 3, 0.5 g, 0.64 mmol) was dissolved in DMF (5 mL), and NBS (0.25 g, 1.42 mmol) was slowly added dropwise at 0 ° C. After 5 hours, 2 M HCl is added and extracted with diethyl ether. After removing water with MgSO ₄ and columning with hexane and recrystallization with acetone, the target compound 5-bromo-2- (5- (5- (5-bromo-3- (5-decylthiophen-2) -Yl) thiophen-2-yl) thiophen-2-yl) thiophen-2-yl) -3- (5-decylthiophen-2-yl) thiophene (BDDT) was obtained. Yield: 0.4 g, 68%. ¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): aromatic (CH), 7.287.25 (m, 2H), 7.28 (2, 2H), 7.16.98 (m, 4H), 6.896.88 ( d, 2H), 6.696.67 (d, 2H), aliphatic (CH) 2.812.76 (t, 4H), 1.721.62 (m, 4H), 1.361.27 (m, 28H), 0.920.87 (t , 6H).

[Example 1] Poly (3,4 ''-di (decylthiophenyl) quaterthiophene) (Poly (3,4 '' '-di (decylthiophenyl) quaterthiophene; PDTQT Synthesis of

The water inside the 100 mL three-necked round flask was completely removed, followed by DMF (5 mL), toluene (3 mL), Ni (COD) (0.44 g, 1.61 mmol), COD (0.17 g, 1.61 mmol), and BPY (0.25 g, 1.61 mmol) was added and stirred at 60 ° C for 1 hour. BDDT (Preparation 4, 0.5 g, 0.54 mmol) is dissolved in toluene (20 mL) and slowly added. After stirring at 80 ° C. for 48 hours, 2-bromonaphthalene is added and stirred for 6 hours. Then, add the reactant to chloroform / methanol (1: 1, 200 mL), filter the solids, and soxhlet with toluene to give poly (3,4 '''-di (decylthiophenyl) as a target compound. Quarterthiophene) (PDTQT) was obtained. Yield: 50%. Mn = 12,700, polydispersity 1.68, ¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): aromatic (CH), 7.56.5 (br, 10H), aliphatic (CH), 3.02.5 (br, 4H), 1.50.5 (br, 38H).

[ Example  2] Poly (3,4 ’’ ’- Di (decylthiophenyl) sexy thiophene ) (Poly (3,4 ’’ ’-di ( decylthiophenyl ) sexithiophene ); PDTST ) Synthesis

The water inside the 100 mL three-necked round flask was completely removed, and then BDDT (Preparation 4, 1 g, 1.07 mmol) and 5,5'-bis (tributylstannyl) -2 in anhydrous toluene (30 mL) -2 , 2'-bithiophene (0.53 g, 1.07 mmol) was added to dissolve it, and then Pd (PPh ₃ ) ₄ (0.03 g) was added thereto and reacted at 80 ° C. under a nitrogen stream for 24 hours, followed by 2-bromonaphthalene (0.05 add g) and react for 6 hours. The reaction product was added to chloroform / methanol (1: 1, 200 mL), and then the solid was filtered and soxhleted using toluene to give poly (3,4 '''-di (decylthiophenyl) Sexythiophene as a target compound. ) (PDTST) was obtained. Yield: 60%. Mn = 7,500, polydispersity 1.48, ¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): aromatic (CH), 7.16.8 (br, 14H), aliphatic (CH), 2.7 (br, 4H) , 1.60.9 (br, 38H).

Example 3 Fabrication of Organic Semiconductor Device

The OTFT device was fabricated in a top-contact manner, using 300 nm n-doped silicon as a gate and SiO ₂ as an insulator. Surface treatment was performed using a piranha cleaning solution (H ₂ SO ₄ : 2H ₂ O ₂ ) and then the surface using Adrich's OTS (octadecyltrichlorosilane) to SAM (Self Assemble Monolayer) was used. The organic semiconductor layer was coated with 0.7 wt% chloroform solution using a spin-coater for 1 minute at 2000 rpm. As the organic semiconductor material, PDTQT and PDTST synthesized in Examples 1 and 2 were used, respectively. The thickness of the organic semiconductor layer was 45 nm using a surface profiler (Alpha Step 500, Tencor). Gold used as the source and drain was deposited to a thickness of 50 nm at 1 A / s. The channel is 1000 μm long and 2000 μm wide. The measurement of OTFT characteristics was done using Keithley 2400 and 236 source / measure units.

The charge mobility was obtained from (S _SD ) ^1/2 and V _G as variables from the saturation region current equation and obtained from the slope.

Where I _SD is the source-drain current, μ or μ _FET is the charge transfer, C ₀ is the oxide capacitance, W is the channel width, L is the channel length, V _G is the gate voltage, and V is _T is the threshold voltage. In addition, the cutoff leakage current I _off is a current flowing in the off state, and is determined as the minimum current in the off state in the current ratio.

The thermal properties of the organic semiconductor compounds (PDTQT and PDTST) synthesized in Examples 1 and 2 were investigated by thermogravimetric analysis (TGA) by heating at 40 캜 to 700 캜 at 10 캜 per minute under a nitrogen atmosphere. The results of the organic semiconductor compounds (PDTQT and PDTST) synthesized in Examples 1 and 2 are shown in FIG. 2. The organic semiconductor compounds (PDTQT and PDTST) synthesized in Examples 1 and 2 can be seen that the decomposition is not observed at a high temperature of more than 300 ℃ has a very excellent thermal stability. In addition, it can be seen from FIG. 3 and FIG. 4 that the organic semiconductor compounds (PDTQT and PDTST) according to Examples 1 and 2 move to the long wavelength region in the solution state and the film to increase the intermolecular pi bonds. Table 1 shows the optical and electrochemical properties of PDTST and PDTQT.

TABLE 1

FIG. 5 is a diagram illustrating an out-of-plane GIXD image of the device fabricated in Example 3 using the organic semiconductor compounds PDTQT and PDTST according to Examples 1 and 2. The interlayer d spacings were 26.34 Å (PDTST). ) And 24.51 dB (PDTQT).

6 shows AFM images (a: film state of PDTST, b: film state of PDTQT) of the device fabricated in Example 3 using the organic semiconductor compounds (PDTQT, PDTST) according to Example 1 and Example 2. The film state of PDTST annealed at 100 ° C., d) the film state of PDTST annealed at 100 ° C.) shows an illustration of increasing crystallinity of the molecule after annealing.

In addition, Figure 7 shows the organic semiconductor characteristics (a: PDTST transfer curve, b: PDTQT transfer curve in the organic semiconductor compound (PDTQT, PDTST) according to Example 3 using the organic semiconductor compounds according to Examples 1 and 2 , c: output curve of PDTST, d: TOF of PDTST).

As shown in Figure 8, it can be seen that the organic semiconductor material synthesized in the present invention is a material excellent in oxidation stability and excellent reproducibility.

Table 2 below describes the characteristics of the OFET device fabricated using the organic semiconductor compounds (PDTQT and PDTST).

TABLE 2

<Explanation of symbols for the main parts of the drawings>
11 substrate 12 insulator
13: organic semiconductor layer (channel material) 14: source
15: drain 16: gate

Claims (5)

An organic semiconductor compound, wherein the thiophene derivative selected from formulas (A) and (B) is a polymer having a conjugation structure in which at least one side chain is substituted.
[Formula A]

[Formula B]

[Wherein R is (C1-C30) alkyl, a is an integer of 0 to 10, and b is an integer of 1 to 10.]
The method of claim 1,
The organic semiconductor compound is an organic semiconductor compound represented by the following formula (1).
[Formula 1]

[Ar ₃ is a chemical bond or (C3-C30) heteroarylene; R ₁ and R ₂ are independently of each other (C1-C30) alkyl; n is an integer from 1 to 100,000.]
The method of claim 2,
An organic semiconductor compound selected from compounds represented by the following formulas (2) and (3).
(2)

(3)

[n is an integer from 1 to 100,000].
An organic thin film transistor using the organic semiconductor compound according to any one of claims 1 to 3 as an organic semiconductor layer.
The method of claim 4, wherein
The organic thin film transistor has a structure of a substrate / gate electrode / insulation layer / organic semiconductor layer / source, drain electrode, or a substrate / gate electrode / insulation layer / source, drain electrode / organic semiconductor layer.

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