KR100865703B1 - Organic semiconductor containing arylacetylene group, and Organic thin film transistor - Google Patents

Abstract

The present invention relates to an acene derivative-based organic semiconductor compound of formula (1) having an arylacetylene substituent capable of pi-electron double chip at the sock end, and an organic thin film transistor employing the same as a semiconductor material.

[Formula 1]

When the organic semiconductor compound according to the present invention is used as a semiconductor layer in an organic thin film transistor, the device exhibits better charge mobility and current point ratio than pentacene.

Arylacetylene, organic thin film transistor, charge mobility, flashing ratio

Description

Organic semiconductor compound having an arylacetylene structure and an organic thin film transistor using the same

1 is a cross-sectional view showing a structure of a general organic thin film transistor made of a substrate / gate / insulation layer / electrode layer (source, drain) / semiconductor layer,

2 is a view showing the characteristics of an organic thin film transistor employing an organic semiconductor compound (A) according to the present invention as an organic active layer ((a) transfer curve (source-drain voltage & square root current-drain voltage), (b ) output curve (current-voltage))

Figure 3 is a diagram showing the thermogravimetric analysis (TGA) curve of the organic semiconductor compounds (A to D) according to the present invention ((a) Compound A; (b) Compound B; (c) Compound C; (d) Compound D)

4 is a diagram showing differential thermal analysis (DSC) curves of organic semiconductor compounds (A and B) according to the present invention ((a) Compound A; (b) Compound B).

<Explanation of symbols for the main parts of the drawings>

     1 substrate 2 gate insulator

     3: organic active layer (channel material) 4: source

     5 drain 6 gate electrode

The present invention relates to an organic thin film transistor (OTFT). More specifically, the present invention relates to a novel organic semiconductor compound having a high pi electron double chip and an organic thin film transistor having improved charge mobility and flashing ratio using the same as a semiconductor layer.

The development of telecommunications in the 21st century and the desire for personal portable communication devices enable ultra-fine processing, high-performance electrical and electronic materials to produce ultra-high integrated circuits, and new-concept displays that enable small, light, thin, and convenient information and communication devices. Need new information and communication materials. Among them, the organic thin film transistor (OTFT) is a portable computer, an organic EL device, a smart card, an electronic tag, an pager, a display driver such as a mobile phone, a memory device such as a cash machine, a tag, etc. The possibility of using it as an important component of the plastic circuitry has been the subject of much research.

Organic thin film transistors using organic semiconductors have advantages in that the manufacturing process is simpler and can be produced at a lower cost than conventional thin film transistors using amorphous silicon and polysilicon. Recently, many studies have been conducted due to the advantages of excellent compatibility.

Many studies have been conducted since G. H. Heilmeier and F. Ebisawa in 1983 first discovered low molecular and polyacetylene-based field effect transistors using Cu-phthalocyamine. The performance of OTFT can be various, but the most important is charge mobility and on / off ratio, and the most important measure 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.

Recently, many organic semiconductor materials for channel layers of organic thin film transistors (OTFTs) have been studied, and their transistor characteristics have been reported. Pentacene, anthracene, thiophene oligomer, etc. are widely studied as low molecular and oligomeric organic semiconductor materials, and Lucent Technologies and 3M have reported high charge mobility of 3.2 to 5.0 cm 2 / Vs or more using pentacene single crystals. Mat.Res.SC.Symp.PrC. 2003, Vol. 771, L6.5.1 to L6.5.11). These values are comparable to or better than amorphous silicon.

However, in the case of pentacene, long-term oxidative and thermal stability is not known, and thus the useful life of pentacene semiconductor devices is also unknown. Another factor to consider with respect to the usefulness of organic semiconductors is the ease of synthesis and purification. Finally, various organic semiconductor materials with a range of physical and chemical properties may be required depending on the particular application.

It is an object of the present invention to provide a novel acene derivative organic semiconductor compound having a substituent containing an arylacetylene group, and another object is to provide high pi electron density, pi electron overlap and intermolecular use of the organic semiconductor compound. It provides crystallinity, thereby providing an organic thin film transistor having excellent charge mobility and high current discrimination ratio.

The present invention is characterized by a monomolecular organic semiconductor compound represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, A is (C ₆ -C ₃₀ ) arylene or (C ₆ -C ₃₀ ) heteroarylene; Ar ₁ and Ar ₂ independently of one another are (C ₆ -C ₃₀ ) arylene or (C ₄ -C ₃₀ ) heteroarylene; m and n are independently of each other an integer from 1 to 4;

A, Ar ₁ or Ar ₂ is independently a hydroxy group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkyl group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkoxy group, (C ₁ -C ₃₀ ) Alkoxy (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) ar (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) aryl group, amino group, mono- or di (C ₆ -C ₃₀ It may be further substituted with one or more substituents selected from an alkylamino group, a mono- or di (C ₆ -C ₃₀ ) arylamino group, a (C ₁ -C ₃₀ ) alkoxycarbonyl group, a cyano group or a halogen group.

In addition, the present invention is a first electrode; Second electrode; And an organic semiconductor compound of Chemical Formula 1 between the first electrode and the second electrode; In an organic thin film transistor including an organic thin film transistor including a substrate, a gate electrode, a gate insulating layer, an organic active layer, and a source / drain electrode, the organic active layer is an organic compound of Formula 1 An organic thin film transistor formed of a semiconductor compound is included.

In the organic semiconductor compound of Formula 1, A may be selected from phenylene, naphthylene, anthylene, phenanthryl, tetrasenylene, pentachenylene, pyrenylene, chrysenylene or florenylene, in particular Illustrative arylene of the following structure.

In addition, Ar ₁ and Ar ₂ of Formula 1 are independently selected from arylene or heteroarylene having the following structure (the bonding position bonded to the acetylene group is selected from the substituent aromatic ring carbon of the following structure).

In the arylene or heteroarylene of the above structure, R ₃ is each independently hydrogen, hydroxy group, linear, branched or cyclic (C ₁ -C ₃₀ ) alkyl group, linear, branched or cyclic (C ₁ -C ₃₀ ) alkoxy Group, (C ₁ -C ₃₀ ) alkoxy (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) ar (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) aryl group, amino group, mono- Or di (C ₆ -C ₃₀ ) alkylamino group, mono- or di (C ₆ -C ₃₀ ) arylamino group, (C ₁ -C ₃₀ ) alkoxycarbonyl group, cyano group.

The organic semiconductor compound of Formula 1 according to the present invention may be exemplified by the following arylacetylene derivatives, but the illustrated compounds do not limit the organic semiconductor compound of the present invention.

In the compound of Formula 1, when Ar ₁ and Ar ₂ are the same, that is, when preparing a symmetric compound, two equivalents of an arylacetylene compound and a dihaloaryl compound may be prepared as shown in Scheme 1 below. The coupling reaction may be performed using CuI / Pd (PPh ₃ ) ₂ Cl ₂ as a coupling reagent in the presence of triethylamine in an organic solvent.

Scheme 1

In addition, in order to prepare an asymmetric compound, the arylacetylene compound and the dihaloaryl compound may be prepared by separating and reacting in steps.

Scheme 2

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, and the arylacetylene compound and halodiaryl compound used as an intermediate may be Those skilled in the art can be easily prepared by conventional organic chemical reactions.

The organic semiconductor compound according to the present invention may be used as a material for forming an organic semiconductor layer (channel material) in an organic thin film transistor, and the organic thin film transistor according to the present invention may include a first electrode; Second electrode; And an organic semiconductor compound of Chemical Formula 1 between the first electrode and the second electrode; It is characterized in that it comprises an organic substrate formed in detail including a substrate 1, the gate electrode 6, the gate insulating layer 2, the organic active layer 3, and the source / drain electrodes 4 and 5 In the thin film transistor, the organic active layer includes an organic thin film transistor formed of the organic semiconductor compound of Chemical Formula 1.

The acene derivative including the arylacetylene group is a low-molecular semiconductor compound having typical p-type semiconductor properties, and includes an acetylene group to increase the intermolecular linearity and when applied to an organic thin film transistor due to the high pi electron double chip, The current spotting ratio can provide a high effect.

Specific examples of the manufacturing method of the organic thin film transistor applying the polymer organic semiconductor compound of Formula 1 according to the present invention as an organic semiconductor layer of the organic thin film transistor are as follows.

As the substrate 1, it is preferable to use n-type silicon used for 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).

As the gate insulating layer 2, it is preferable to use silicon dioxide (SiO ₂ ) having a high insulation rate and easily forming on the gate electrode.

The structure of the organic thin film transistor of the present invention is not only the top-contact of the substrate / gate electrode / insulation layer / organic active layer / source and drain electrode but also the substrate / gate electrode / insulation layer / source, drain electrode / derivative conductor. It includes both the form of bottom-contact of the layer. In addition, it may or may not coat HMDS (1,1,1,3,3,3-hexamethyldisilazane), octyltrichlorosilane (OTS), or octadecyltrichlorosilane (OTDS) as a surface treatment between the source and drain electrodes and the organic active layer.

The gate electrode 6 and the source-drain electrodes 4 and 5 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).

The organic active 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 coating, dipping or ink spraying, wherein the organic active deposition Silver may be formed using a high temperature solution at 40 ° C. or higher, and the thickness thereof is preferably about 500 kPa.

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.

EXAMPLE

[Production Example 1] Preparation of 4-bromoalkylbenzene (2)

Compound 1 [4- Bromoalkanoylbenzene  (1)]

To the mixture of bromobenzene (77 g, 0.49 mol) and AlCl ₃ (39.7 g, 0.294 mol) was slowly added dropwise alkanoyl chloride (46.7 g, 0.245 mol) and stirred at 50 ° C for 1 hour. The reaction temperature was lowered to room temperature and cold water was added to the reaction mixture and extracted with CH ₂ Cl ₂ . The extracted organic layer was washed with 2M HCl and water and dried over anhydrous MgSO ₄ . MgSO ₄ was filtered through a filter paper and the filtered solution was removed using a rotary vacuum evaporator to remove the solvent. Recrystallization with EtOH gave a white solid.

4-Bromohexanoylbenzene (1a): ¹ H NMR (CDCl ₃ , 300 MHz): δ 7.81-7.86 ppm (d, 2H, J = 8.61 Hz), 7.58-7.55 ppm (d, 2H, J = 8.80 Hz) , 2.93-2.88 ppm (t, 2H, J = 7.36 kPa), 1.76-1.66ppm (m, 2H), 1.36-1.34 ppm (m, 4H), 0.92-0.88 ppm (t, 3H, J = 6.81 ㎐)

4-Bromodecanoylbenzene (1b): ¹ H NMR (CDCl ₃ , 300 MHz): δ. 7.84-7.81 ppm (d, 2H, J = 8.42 kPa), 7.61-7.58 ppm (d, 2H, J = 8.37 kPa), 2.95-2.90 ppm (t, 2H, J = 7.38 kPa), 1.77- 1.68 ppm (m, 2H), 1.28 ppm (m, 12H), 0.91-0.86 ppm (t, 3H, J = 6.55 kPa)

Preparation of Compound 2 [4-Bromoalkylbenzene (2)]

Compound 1 (159 g, 051 mol), hydrazine hydrate (70 mL) and KOH (114.46 g, 2.04 mol) were dissolved in triethylene glycol (700 mL) and refluxed for 2 hours. The reaction temperature was lowered to room temperature, water and HCl were added to the reaction mixture, and extracted with CH ₂ Cl ₂ . The extracted organic layer was washed with water and dried over anhydrous MgSO ₄ . MgSO ₄ was filtered through a filter paper and the filtered solution was removed using a rotary vacuum evaporator to remove the solvent. Colorless liquid was obtained by column chromatography using n-Hexane solvent.

4-Bromohexylbenzene (2a): ¹ H NMR (CDCl ₃ , 300 MHz): δ. 7.45-7.42 ppm (d, 2H, J = 8.33 kPa), 7.11-7.08 ppm (d, 2H, J = 8.32 kPa), 2.63-2.58 ppm (t, 2H, J = 7.69 kPa), 1.67- 1.62 ppm (m, 2H), 1.40-1.35 ppm (m, 6H), 0.97-0.93 ppm (t, 3H, J = 6.60 kPa)

4-Bromodecylbenzene (2b): ¹ H NMR (CDCl ₃ , 300 MHz): δ. 7.43-7.40 ppm (d, 2H, J = 8.18 kPa), 7.09-7.06 ppm (d, 2H, J = 8.21 kPa), 2.61-2.56 ppm (t, 2H, J = 6.8 kPa), 1.64- 1.58 ppm (m, 2H), 1.3 ppm (m, 21H), 0.94-0.90 ppm (t, 3H, J = 6.57 kPa)

Production Example 2 Preparation of 1-bromodesyloxybenzene (3)

4-Bromophenol (5 g, 28.9 mmol) was dissolved in ethanol, bromodecane (7.06 g, 6.6 mL, 31.79 mmol), NaI (0.3 g, 2.02 mmol) and KOH (1.78 g, 31.79 mmol) were added and refluxed for 22 hours. I was. The reaction temperature was lowered to room temperature and the solvent was completely removed using a rotary vacuum evaporator. Water was added to the reaction mixture and extracted with EtOAc. The extracted organic layer was washed with water and dried over anhydrous MgSO ₄ . MgSO ₄ was filtered through a filter paper and the filtered solution was removed using a rotary vacuum evaporator to remove the solvent. Colorless liquid was obtained by column chromatography using n-Hexane solvent.

¹ H NMR (CDCl ₃ , 300 MHz): δ 7.4-7.37 ppm (d, 2H, J = 8.81 Hz), 6.81-6.78 ppm (d, 2H, J = 8.84 Hz), 3.95-3.91 ppm (t , 2H, J = 6.55 kPa), 1.82-1.77 ppm (m, 2H), 1.31 ppm (m, 14 H), 0.94-0.90 ppm (t, 3H, J = 6.52 kPa)

Production Example 3 Preparation of 1-ethynyl-4-alkylbenzene (5)

Compound 4 [(2- (4- alkylphenyl ) ethynyl ) trimethylsilane Manufacture of

Compounds 2 or 3 (10 g, 33.41 mol) prepared from Preparation Examples 2 and 3 were added with anhydrous triethylamine (50 mL), followed by trimethylsilyl-acetylene (4.6 mL, 33.41 mol), Pd (dppf) Cl ₂ (0.54 g, 0.66 mmol) and CuI (0.38 g, 2.00 mmol) were added and refluxed for 16 hours. The reaction temperature was lowered to room temperature and the volatiles were removed using a rotary vacuum evaporator. Colorless liquid was obtained by column chromatography using n-Hexane solvent.

2- (4-hexylphenyl) ethynyl) trimethylsilane (4a) ¹ H NMR (CDCl ₃ , 300 MHz): δ 7.51-7.48ppm (d, 2H, J = 8.18 Hz), 7.20-7.18 ppm (d, 2H , J = 8.14 kPa), 2.70-2.65 ppm (t, 2H, J = 7.69 kPa), 1.69-1.66 ppm (m, 2H), 1.14 ppm (m, 6H), 1.01-0.99 ppm (t, 3 H, J = 6.77 Hz), 0.38 ppm (s, 9 H)

(2- (4-decylphenyl) ethynyl) trimethylsilane (4b) ¹ H NMR (CDCl ₃ , 300 MHz): δ 7.52-7.47 ppm (dd, 2H, J = 8.17 Hz, J = 8.53 Hz), 7.21-7.12 ppm (dd, 2H, J = 7.98 μs, J = 8.20 μs), 2.72-2.62 ppm (m, 2 H), 1.69 ppm (m, 2 H), 1.9 ppm (s, 9 H), 1.27-1.22 ppm (m, 14H), 1.04-0.99 ppm (t, 3H, J = 6.53)

2- (4-decyloxyphenyl) ethynyl) trimethylsilane (4c) ¹ H NMR (CDCl ₃ , 300 MHz): δ 7.43-7.40 ppm (d, 2H, J = 8.84 Hz), 6.84-6.81 ppm (d, 2H , J = 8.86 kPa), 3.98-3.94 ppm (t, 2H, J = 6.58 kPa), 1.81-1.74 ppm (m, 2 H), 1.30 ppm (m, 14 H), 0.93-0.89 ppm (t, 3 H, J = 6.70 Hz), 0.26 ppm (s, 9 H)

Preparation of Compound 5 [1-ethynyl-4-alkylbenzene]

THF (70 mL) was added to the prepared compound 4 (9.3 g, 29.56 mol), and 1M t-Bu ₄ NF (10 mL, 10.05 mmol) dissolved in THF was slowly added at room temperature, followed by stirring for 2 hours. Solvent was removed using a rotary vacuum evaporator. Colorless liquid was obtained by column chromatography using n-Hexane solvent.

1-ethynyl-4-hexylbenzene (5a) ¹ H NMR (CDCl ₃ , 300 MHz): δ. 7.47-7.44 ppm (d, 2H, J = 8.11 kPa), 7.19-7.16 ppm (d, 2H, J = 8.02 kPa), 3.07 ppm (s, 1H), 2.67-2.62 ppm (t, 2H , J = 7.68 kPa), 1.66-1.57 ppm (m, 2H), 1.34 ppm (m, 6H), 0.96-0.91 ppm (t, 3H, J = 6.34 kPa)

1-decyl-4-ethynylbenzene (5b) ¹ H NMR (CDCl ₃ , 300 MHz): δ. 7.47-7.45 ppm (d, 2H, J = 7.89 kPa), 7.19-7.17 ppm (d, 2H, J = 7.91 kPa), 3.08 ppm (s, 1H), 2.68-2.63 ppm (t, 2H , J = 7.70 Hz), 1.69-1.63 ppm (m, 2H), 1.35 ppm (m, 14 H), 0.97-0.93 ppm (t, 3H, J = 6.47 Hz)

1- (decyloxy) -4-ethynylbenzene (5c) ¹ H NMR (CDCl ₃ , 300 MHz): δ 7.47-7.44 ppm (d, 2H, J = 8.79 kPa), 6.87-6.84ppm (d, 2H, J = 8.81 kPa), 3.99-3.95 ppm (t, 2H, J = 6.55 kPa), 1.81 ppm (m, 2H), 1.32 ppm (m, 14H), 0.94-0.91 ppm (t, 3H, J = 6.95 kW)

Production Example 4 Preparation of 2,6-dibromoanthracene (7)

Preparation of Compound 6 [2,6-dibromoanthraquinone]

Dissolve t-Butylnitrite (30.3 g, 0.294 mol) and CuBr ₂ (50.25 g, 0.225 mol) in 150 ml of acetonitrile and heat to 65 ° C. 2,6-diamino-anthraquinone (20 g, 0.084 mol) is slowly added and reacted for 1 hour. The reaction solution is poured into 6N HCl and stirred for 1 hour. The solid is filtered off and washed with HCl, water and EtOH. The filtered compound was recrystallized from 1,4-dioxane to give 13.09 g (42.6%) brown solid.

¹ H-NMR (300 MHz, CDCl ₃ , ppm): 8.45 (s, 2H), 8.20 (d, 2H), 7.98 (d, 2H)

Preparation of Compound 7 [2,6-dibromoanthracene]

Compound 6 (2,6-dibromoanthraquinone) (15 g, 40.98 mmol), 600 ml glacial acetic acid, 105 ml HI and 60 ml H ₃ PO ₂ were added thereto, and the mixture was refluxed at 150 ° C. for 4 days. Washed with water and ethanol, and soxhlet with toluene to give 6.9 g (50%) of a light green solid.

¹ H-NMR (300 MHz, CDCl 3, ppm): 8.31 (s, 2H), 8.18 (s, 2H), 7.90 (d, 2H), 7.56 (d, 2H)

Example 1 Preparation of Compound A

Pd (pph ₃ ) ₂ Cl ₂ (6 mol%) of compound 7 (3 g, 9 mmol), phenylacetylene, (0.312 g, 2 mmol), CuI (I) (1.151 g, 2 mmol) prepared from Preparation Example 4. To anhydrous toluene (30 mL) and anhydrous triethylamine (30 mL) and refluxed for 18 hours. The reaction temperature was lowered to room temperature and the volatiles were removed using a rotary vacuum evaporator. After washing with dichloromethane, the solid was soxhlet with toluene to obtain 2.41 g (71.3%) of a light green solid.

MS m / z (%): 378 (M +)

Examples 2 to 4 Preparation of Compounds B, C, and D

Compound 7 (1 g, 2.98 mmol) prepared from Example 4 was added to anhydrous i-Pr ₂ NH (15 mL) and anhydrous toluene (15 mL), followed by compound 5 (5396 mmol) prepared in Preparation Example 3, Pd (dppf) Cl ₂ (6 mol%) and CuI (34 mg, 0.18 mmol) were added and refluxed for 16 hours. The reaction temperature is lowered to room temperature and the precipitate is filtered off. Wash the precipitate with toluene. Purification with soxhlet using Tolene solvent.

Compound B: light yellow solid, ¹ H NMR (CDCl ₃ , 300 MHz): δ 8.37 ppm (s, 2H), 8.21 ppm (s, 2H), 7.99-7.97 ppm (d, 2H, J = 8.64 Hz), 7.57-7.52 ppm (m, 6H), 7.28-7.20 ppm (d, 4H, J = 7.44 kPa), 2.68-2.63 ppm (t, 4H, J = 7.13 kPa), 1.65 ppm (m, 4H), 1.34 ppm (m, 12H), 0.91 ppm (m, 6H)

Compound C: light green green, ¹ H NMR (CDCl ₃ , 300 MHz): δ 8.36 ppm (s, 2H), 8.21 ppm (s, 2H), 7.99-7.96 ppm (d, 2H, J = 8.81 Hz), 7.58 -7.52 ppm (m, 6H), 7.23-7.20 ppm (d, 4H, J = 8.16 kPa), 2.68-2.63 ppm (t, 4H, J = 7.68 kPa), 1.68-1.61 ppm (m, 4H), 1.34 -1.30 ppm (m, 28H), 0.93-0.89 ppm (t, 6H, J = 6.71 kPa)

Compound D: light green green, EI, MS m / z (%): 691 (M +)

Example 5 Fabrication of Organic Thin Film Transistor

650 kW was deposited on the cleaned glass substrate 1 with aluminum used as the gate electrode 6 by vacuum deposition, and then 5,500 kPa was coated with PVP used as the gate insulating film 2 by spin coating. Gold (Au), which is used as the source-drain electrodes 4 and 5, was deposited thereon by vacuum deposition. The length of the channel is 30 μm and the width is 150 μm. Compound A synthesized in Example 1 was deposited at 500 Pa by a vacuum deposition method at a substrate temperature of 80 ° C. at a rate of 0.3 μs / sec, thereby fabricating a bottom-contact OTFT device shown in FIG. 1. After measuring the current transfer characteristics using the device, the current transfer curve is shown in Figure 2, the measured values of the overall physical properties of the device is shown in Table 1. The charge mobility was calculated from the current equation of the saturation region using the current transfer curve. That is, the charge mobility was obtained from the slope of the graph obtained by (ISD) ^1/2 and V _G as variables from the following saturation region current equation.

In the above formula, I _SD is the source-drain current, μ or μ _FET is the charge mobility, CO is the insulation capacitance, L is the channel length, V _G is the gate voltage, and V _T is the threshold voltage.

The cutoff leakage current I _off is a current flowing in the off state, and is determined as the minimum value in the off state from the current ratio. Subthreshold slope (SS) represents the degree of change of the drain current with respect to the change of the gate voltage before reaching the threshold voltage, and was obtained as the amount of change in the gate voltage required to increase the drain current 10 times. The threshold voltage (V _th ) is the minimum voltage required to drive the OTFT device, and is obtained by the intersection of the slope of the linear portion and the value in the off state in the I _D -V _G graph.

Example 6 Evaluation of Thermal Properties of Organic Semiconductor Compound

Thermogravimetric properties of the organic semiconductor compounds (Compounds A, B, C, D) prepared by Examples 1 to 4 were heated at 10 ° C. per minute from 40 ° C. to 700 ° C. under a nitrogen atmosphere and then thermogravimetrically It was investigated by analysis (TGA) and differential calorimetry (DSC), the results are shown in Figures 3 and 4. Compound A was observed to lose weight at 285 ° C. and 490 ° C., demonstrating that the triple bonds decomposed at 285 ° C. and further decomposition of the material at 490 ° C. In the case of compounds B, C, and D, the 5% weight loss was measured at 453 ° C, 438 ° C, and 417 ° C. The compound A had a phase change at 325 ° C. It is recognized. Compound B was determined to have a phase change point at 152 ° C, 178 ° C, and 218 ° C. This differential calorimetry reveals indirectly that Compound A has liquid crystalline properties by observing several phase transition temperatures.

Example 7 Characterization of Organic Thin Film Transistor

The hole mobility and the flashing ratio of the organic thin film transistor prepared according to Example 5 were evaluated. 2 shows the characteristics of the organic thin film transistor employing the compound A of the present invention as an organic active layer. The semiconductor characteristics of Compound A were p-type, and thus the measured values of the overall physical properties of the devices of the organic thin film transistor employing the same are shown in Table 1.

Comparative Example 1

An organic thin film transistor device was manufactured in the same manner as in Example 5, except that pentacene represented by the following compound E was used as an organic active layer-forming material, and the current transfer characteristics thereof were measured. Is shown in Table 1.

TABLE 1

As can be seen from Table 1, the device of Example 5 employing Compound A of the present invention has a higher charge mobility and a current point ratio than the device of Comparative Example 1 employing pentacene, and has a cutoff leakage current and a threshold voltage. , The subthreshold slope was determined to be very low compared to Comparative Example 1. Therefore, it can be seen that the performance of the organic thin film transistor device is very excellent.

As described above, the acene derivative having the arylacetylene substituent of the present invention at the sock end is a single-molecule organic semiconductor having a novel structure, which can be easily synthesized, and is stable at room temperature, and the organic thin film transistor employing them is excellent. It exhibits semiconductor characteristics, that is, high charge mobility and flicker ratio characteristics, and has a very low blocking leakage current, threshold voltage, and sub-threshold slope, which can be used as an active layer for an organic thin film transistor device.

Claims (10)

An organic semiconductor compound represented by Formula 1 below. [Formula 1]

In Formula 1, A is

ego; Ar ₁ and Ar ₂ independently of one another are (C ₆ -C ₃₀ ) aryl or (C ₄ -C ₃₀ ) heteroaryl; m and n are independently of each other an integer of 1; A, Ar ₁ or Ar ₂ is independently a hydroxy group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkyl group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkoxy group, (C ₁ -C ₃₀ ) Alkoxy (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) ar (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) aryl group, amino group, mono- or di (C ₆ -C ₃₀ One or more substituents selected from an alkylamino group, a mono- or di (C ₆ -C ₃₀ ) arylamino group, a (C ₁ -C ₃₀ ) alkoxycarbonyl group, a cyano group or a halogen group. delete delete The method of claim 1, Ar ₁ and Ar ₂ are independently an organic semiconductor compound, characterized in that aryl or heteroaryl of the structure.

Wherein R ₃ is each independently hydrogen, a hydroxy group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkyl group, a linear, branched or cyclic (C ₁ -C ₃₀ ) alkoxy group, (C ₁ -C ₃₀ ) Alkoxy (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) ar (C ₁ -C ₃₀ ) alkyl group, (C ₅ -C ₃₀ ) aryl group, amino group, mono- or di (C ₆ -C ₃₀ ) Is selected from alkylamino group, mono- or di (C ₆ -C ₃₀ ) arylamino group, (C ₁ -C ₃₀ ) alkoxycarbonyl group, cyano group, the bonding position to which the substituent is bonded is selected from the carbon of the substituent ring . A first electrode; Second electrode; An organic semiconductor compound represented by Chemical Formula 1 according to claim 1 between the first electrode and the second electrode; Organic thin film transistor comprising a. The method of claim 5, wherein And the organic semiconductor compound is formed into a thin film by vacuum deposition, screen printing, printing, spin coating, dipping or ink spraying. In an organic thin film transistor formed by including a substrate 1, a gate electrode 6, a gate insulating layer 2, an organic active layer 3, and source / drain electrodes 4 and 5, The organic thin film transistor, wherein the organic active layer is formed of the organic semiconductor compound of Formula 1 according to claim 1. The method of claim 7, wherein The gate electrode 6 and the source-drain electrodes 4 and 5 are made of gold (Au), silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr) and indium tin oxide (ITO). An organic thin film transistor, characterized in that formed of a material selected from the group. The method of claim 7, wherein The organic thin film transistor, wherein the organic active layer (3) is formed into a thin film by vacuum deposition, screen printing, printing, spin coating, dipping or ink spraying. The method of claim 7, wherein The substrate 1 may be made of glass, polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVP), polyacrylate, An organic thin film transistor, which is formed of a material selected from the group consisting of polyimide, polynorbornene, and polyethersulfone (PES).

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