JP2022037676A - Low-molecular-weight compound, polymer compound, organic semiconductor material and organic semiconductor device - Google Patents

Abstract

To provide a low-molecular-weight compound that is available for an application process and shows excellent semiconductor device properties, a polymer compound, an organic semiconductor material and an organic semiconductor device.SOLUTION: A low-molecular-weight compound is represented by following formula(1) or formula (2), where R is an alkyl group, A is a heteroaromatic ring, B is a heterocycle. A polymer compound is represented by the repetition of the structure through a heteroaromatic ring. These compounds are used as starting materials to make an organic semiconductor material and an organic semiconductor device.SELECTED DRAWING: None

Description

The present invention relates to low molecular weight compounds, high molecular weight compounds, organic semiconductor materials and organic semiconductor devices.

In recent years, organic thin-film solar cells and organic thin-film transistors using organic semiconductor materials have been attracting attention. A semiconductor device made of an organic semiconductor material has an advantage of being thinner and more flexible than a semiconductor device made of an inorganic semiconductor material or the like. Therefore, research and development of various organic semiconductor materials are being carried out.

On the other hand, in semiconductor devices made of organic semiconductor materials, organic semiconductor materials having an extended π-conjugated system are attracting attention in order to improve semiconductor characteristics such as charge mobility and photoelectric conversion efficiency. For example, a compound having an extended skeleton of a π-conjugated system based on naphthobisthiadiazole is known (for example, Patent Documents 1 and 2, Non-Patent Document 1 and the like).

International Publication No. 2019/0393969 Japanese Unexamined Patent Publication No. 2018-145125

I. Osaka et al., J. Am. Chem. Soc. 2012, 134, 3498

Compounds used in organic semiconductor materials are required to have characteristics such as high charge mobility, and although various organic semiconductor materials have been disclosed so far, material development is still under development, and further organic semiconductor materials. Is required.

The present invention has been made in view of the above matters, and an object thereof is a low molecular weight compound, a high molecular weight compound, an organic semiconductor material and an organic semiconductor which can be used in a coating method and exhibit good semiconductor device characteristics. It is to provide the device.

（式１及び式２中、Ｒはアルキル基を表し、Ａはヘテロ芳香環を表し、式２中、Ｂはヘテロ環を表す。）
ことを特徴とする。 The small molecule compound according to the first aspect of the present invention is
Represented by Equation 1 or Equation 2,

(In Formulas 1 and 2, R represents an alkyl group, A represents a heteroaromatic ring, and B in Formula 2 represents a heterocycle.)
It is characterized by that.

（式３及び式４中、Ｒはアルキル基を表し、Ａはヘテロ芳香環を表し、Ａｒはヘテロ芳香環を表し、式４中、Ｂはヘテロ環を表す。）
ことを特徴とする。 The polymer compound according to the second aspect of the present invention is
Including the repeating unit represented by the formula 3 or the formula 4.

(In formulas 3 and 4, R represents an alkyl group, A represents a heteroaromatic ring, Ar represents a heteroaromatic ring, and B in formula 4 represents a heterocycle.)
It is characterized by that.

The organic semiconductor material according to the third aspect of the present invention is
A small molecule compound according to a first aspect of the present invention or a high molecular compound according to a second aspect of the present invention.
It is characterized by that.

The organic semiconductor device according to the fourth aspect of the present invention is
It has an active layer containing an organic semiconductor material according to a third aspect of the present invention.
It is characterized by that.

According to the present invention, it is possible to provide a low molecular weight compound, a high molecular weight compound, an organic semiconductor material and an organic semiconductor device that can be used in a coating method and exhibit good semiconductor device characteristics.

It is a graph of the current density-voltage characteristic of the organic thin-film solar cell element using compound 7a. It is a graph of the spectral sensitivity characteristic of the organic thin film solar cell element using compound 7a. It is a graph of the current density-voltage characteristic of the organic thin film solar cell element using compound 7b. It is a graph of the spectral sensitivity characteristic of the organic thin film solar cell element using compound 7b. It is a graph of the current density-voltage characteristic of the organic thin film solar cell element using compound 7c. It is a graph of the spectral sensitivity characteristic of the organic thin film solar cell element using compound 7c. It is a graph of the current density-voltage characteristic of the organic thin film solar cell element using compound 7d. It is a graph of the spectral sensitivity characteristic of the organic thin film solar cell element using compound 7d. It is a graph of the current density-voltage characteristic of the organic thin-film solar cell element using compound 8. It is a graph of the spectral sensitivity characteristic of the organic thin film solar cell element using compound 8.

(Small molecule compound)
The small molecule compound according to this embodiment is represented by the formula 1 or the formula 2.

In formulas 1 and 2, R represents an alkyl group. The alkyl group may be branched or linear, but is preferably branched from the viewpoint of solubility in a solvent. The number of carbon atoms of the alkyl group is not limited, but is preferably 6 to 28.

In formulas 1 and 2, A represents a heteroaromatic ring. The heteroaromatic ring may be a monocyclic ring or a fused ring, but the fused ring is preferably a bicyclic or tricyclic ring. Further, the number of ring members of the heteroaromatic ring constituting A is preferably 5 or 6. Examples of the heteroaromatic ring include structures of formulas 5a to 5f. In formula 1, in formulas 5a to 5f, R ₁ to R ₃ represent hydrogen or a substituent such as an alkyl group, an ester group, an alkoxy group, or an alkylthio group. _R4 represents an alkyl group. The alkyl moiety of R ₁ to R ₄ may be branched chain or linear. The number of carbon atoms in the alkyl moiety is not limited, but is preferably 6 to 28. Further, in the formula 2, R ₁ represents B in the formulas 5a to 5f. _R2 to _R4 are synonymous with the above _R2 to _R4 .

In Equation 2, B represents a heterocycle. The number of ring members of the heterocycle is preferably 4 to 6. As the heterocycle, for example, the structures represented by the formulas 6a to 6g are preferable.

Further, X in the formulas 6a to 6g is an independently hydrogen, an alkyl group, a halogen or a optionally substituted heteroaromatic ring, and R5 is synonymous with R in the formula ₁ .

The low molecular weight compounds represented by the formulas 1 and 2 have a structure in which two pyrroles are condensed with naphthalene of naphthithiadiazole, and a heteroaromatic ring is further condensed with each pyrrole, and the π-conjugated system is expanded. There is. Therefore, the small molecule compounds represented by the formulas 1 and 2 have a strong intramolecular interaction and have high crystallinity.

On the other hand, when used as an organic semiconductor device material in the coating method, solubility in organic solvents such as toluene, chlorobenzene, and chloroform becomes a problem, and compounds with an extended π-conjugated system have reduced solubility, resulting in organic semiconductor devices. It can be difficult to use as a material. However, the small molecule compounds represented by the formulas 1 and 2 have excellent solubility in organic solvents because the alkyl group is bonded to the nitrogen of each pyrrole. Therefore, the compounds represented by the formulas 1 and 2 are easily dissolved in an organic solvent and are useful when used as an organic semiconductor device material in a coating method.

The small molecule compounds represented by the above formulas 1 and 2 can be synthesized with reference to Examples described later.

(Polymer compound)
The polymer compound according to this embodiment contains a repeating unit represented by the formula 3 or the formula 4.

In formulas 3 and 4, R has the same meaning as R in formulas 1 and 2 described above. In formulas 3 and 4, A represents a heteroaromatic ring. The heteroaromatic ring may be a monocyclic ring or a fused ring, but the fused ring is preferably a bicyclic or tricyclic ring. Further, the number of ring members of the heteroaromatic ring constituting A is preferably 5 or 6. Examples of the heteroaromatic ring include structures of formulas 7a to 7f. _R6 , _R7 , and R8 are synonymous with _R2 , R3 _, and _R4 of equations 5a to 5f, _respectively .

Further, in the formula 4, B represents a heterocycle. The number of ring members of the heterocycle is preferably 4 to 6. As the heterocycle, for example, the structures represented by the formulas 8a to 8d are preferable.

In Formulas 3 and 4, Ar represents a heteroaromatic ring, and examples thereof include thiophene, bitiophene, bithiazole, thienothiophene, and benzodithiophene. These heteroaromatic rings may be substituted.

The weight average molecular weight of the polymer compound represented by the formulas 3 and 4 is preferably in the range of 10,000 to 1,000,000. The number average molecular weight is preferably in the range of 10,000 to 200,000.

(Organic semiconductor material)
The low molecular weight compounds represented by the formulas 1 and 2 and the high molecular weight compounds represented by the formulas 3 and 4 are p-type organic semiconductors (electron donors / donors) or n-type organic semiconductors (electron acceptors / acceptors). ), It can be used as an organic semiconductor material. This organic semiconductor material can form an active layer of an organic semiconductor device by a coating method such as a wet film forming method.

The organic semiconductor material contains only the low molecular weight compound represented by the formulas 1 and 2, and the high molecular weight compound represented by the formulas 3 and 4, but also contains other organic semiconductor materials and other components. May be good. When used as a material for an organic thin film solar cell, if the donor is a low molecular weight compound represented by the formulas 1 and 2 and a high molecular weight compound represented by the formulas 3 and 4 as other organic semiconductor materials to be combined. It is preferable to contain an electron-accepting compound that exerts a function as an acceptor, and if the low molecular weight compound represented by the formulas 1 and 2 and the high molecular weight compound represented by the formulas 3 and 4 are acceptors. It preferably contains an electron donating compound that functions as a donor. The electron-accepting compound may be any compound that functions as a so-called n-type organic semiconductor material, and known compounds such as fullerene derivatives such as PCBM and polymers of thiophene-based low molecular weight compounds and thiophene-based compounds are used. The electron donating compound may be any compound that functions as a so-called p-type organic semiconductor material, and known compounds such as polythiophene and polymers of thiophene-based compounds are used.

(Organic semiconductor device)
The organic semiconductor device is a photoelectric conversion element such as an organic thin-film solar cell or a solid-state imaging element, an organic transistor, or the like, and the active layer contains the above-mentioned organic semiconductor material. Since the above-mentioned organic semiconductor material has excellent photoelectric conversion efficiency, it can be suitably used for an organic thin-film solar cell. The organic thin-film solar cell contains the above-mentioned organic thin-film solar cell material in the photoactive layer. The organic thin-film solar cell can be manufactured by a known method using the above-mentioned organic thin-film solar cell material. The structure of the organic thin-film solar cell is not particularly limited as long as it has a structure in which a photoactive layer is provided between a pair of electrodes. The configuration of the organic thin-film solar cell includes, for example, the following aspects. The p-layer and p-material are layers and materials containing the above-mentioned electron donating compound, and the n-layer and n-material are layers and materials containing the above-mentioned organic thin-film solar cell material.
(A) Electrode / p material and n material mixed layer / electrode (B) Electrode / p layer / p material and n material mixed layer / n layer / electrode (C) Electrode / p layer / n layer / electrode

Hereinafter, the characteristics of the compound and the organic thin-film solar cell using the compound will be described based on Examples. The present invention is not limited to these examples.

(Synthesis of Compounds 7a-7d)
Compounds 7a-7d were synthesized by sequentially synthesizing based on the following scheme.

Compound 1 as a raw material was synthesized and used with reference to "Chatterjee et al., NPG Asia Materials, 2018, 1016-1028". In addition, Compound 2 was synthesized and used with reference to "Hyeongjin Hwang et al., J. Mater. Chem. A, 2017, 5, 10269".

(Synthesis of Compound 3)
In an argon atmosphere, compound 1 (500 mg, 1.14 mmol), compound 2 (1.46 g, 2.51 mmol), tetrakis (triphenylphosphine) palladium (0) (58 mg, 4.4 mol%), and Toluene (30 mL) was added and reacted at 110 ° C. for 12 hours. After cooling to room temperature, water was added to the reaction solution, and the mixture was extracted with chloroform. The extracted organic layer was washed successively with saturated brine and water. The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: chloroform (1: 1) solvent as a moving layer to obtain Compound 3 as a red solid (980 mg, yield 99%).

The physical property data of the obtained compound 3 are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 7.85 (s, 2H), 7.19 (s, 2H), 2.80 (d, J = 7.7Hz, 4H), 1.83- 1.77 (m, 4H), 1.66-1.19 (m, 32H), 0.93-0.83 (m, 6H)

(Synthesis of compound 4a)
Compound 3 (980 mg, 1.13 mmol), sodium azide (294 mg, 4.52 mmol), and dimethyl sulfoxide (30 mL) were added to the reaction vessel under an argon atmosphere, and the mixture was reacted at 90 ° C. for 12 hours. After cooling to room temperature, water was added to the reaction solution, the mixture was extracted with ethyl acetate, and the extracted organic layer was washed with water. The solvent was distilled off under reduced pressure and dried to obtain a crude product as a blue solid (490 mg). Under an argon atmosphere, the crude product (290 mg, 1.13 mmol), 1-bromo-2-hexyldecane (414 mg, 1.36 mmol), potassium carbonate (374 mg, 2.71 mmol), and dimethylformamide (100 mL) were added to the reaction vessel. In addition, the reaction was carried out at 180 ° C. for 12 hours. After cooling to room temperature, water was added to the reaction solution, the mixture was extracted with hexane, and the extracted organic layer was washed with water. The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: chloroform (1: 1) solvent as a moving layer to obtain compound 4a as a red solid (320 mg, yield 37%).

The physical property data of the obtained compound 4a are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 7.01 (s, 2H), 2.78-2.76 (m, 4H), 1.85-1.81 (m, 4H), 0. 97-0.64 (m, 104H)

(Synthesis of compound 4b)
The synthesis was carried out in the same manner as in the synthesis method of compound 4a except that 1-bromo-2-hexyldecane was replaced with 1-bromo-2-butyloctane (234 mg, 0.936 mmol), and compound 4b was obtained as a red solid (compound 4b). 195 mg, yield 35%).

The physical property data of the obtained compound 4b are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 7.06 (s, 2H), 2.82 (d, J = 7.6Hz, 4H), 1.92-1.79 (m, 4H), 1.52-1.22 (m, 34H), 1.05-0.62 (m, 48H), 0.50 (t, J = 6.6Hz, 6H)

(Synthesis of compound 5a)
Under an argon atmosphere, dimethylformamide (4.0 mL) and phosphoryl chloride (0.5 mL, 5.37 mmol) were added to the reaction vessel, and the mixture was stirred at 0 ° C. for 30 minutes, then heated to room temperature and stirred for 2 hours. Then, the reaction solution was added dropwise to the solution containing compound 4a (320 mg, 0.245 mmol) and 1,2-dichloroethane (20 mL). Then, it reacted at 80 degreeC for 1 hour. After cooling to room temperature, water was added to the reaction solution, the mixture was extracted with chloroform, and the extracted organic layer was washed with water. The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: chloroform (1:10) solvent as a moving layer to obtain compound 5a as a red solid (260 mg, yield 78%).

The physical property data of the obtained compound 5a are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 10.16 (s, 2H), 3.23-3.18 (m, 4H), 1.95-1.89 (m, 4H), 1. 76-1.69 (m, 2H), 1.41-0.62 (m, 102H)

(Synthesis of compound 5b)
Synthesis was carried out in the same manner as in the synthesis method of compound 5a except that compound 4a was replaced with compound 4b (195 mg, 0.164 mmol) to obtain compound 5b as a red solid (184 mg, yield 90%).

The physical property data of the obtained compound 5b are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 10.10 (s, 2H), 3.20-3.02 (m, 4H), 2.82 (d, J = 7.6Hz, 4H), 1.92-1.85 (m, 4H), 1.70-1.13 (m, 32H), 0.95-0.56 (m, 46H), 0.47-0.41 (m, 6H) )

(Synthesis of compound 7a)
Under an argon atmosphere, compound 5a (130 mg, 0.0956 mmol), compound 6a (66 mg, 0.287 mmol), pyridine (1.0 mL), and chloroform (20 mL) were added to the reaction vessel, and the mixture was reacted at 60 ° C. for 5 hours. rice field. After cooling to room temperature, water was added to the reaction solution, the mixture was extracted with chloroform, and the extracted organic layer was washed successively with 1N hydrochloric acid and water. The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: chloroform (1:10) solvent as a moving layer to obtain compound 7a as a dark green solid (110 mg, yield 64%).

The physical property data of the obtained compound 7a are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 8.74 (s, 2H), 8.41 (dd, J = 9.9,6.5Hz, 2H), 7.55-7.46 (m) , 2H), 3.07 (d, J = 7.9Hz, 4H) 1.83-1.77 (m, 4H), 1.42-1.30 (m, 4H), 1.15-1. 09 (m, 6H), 0.96-0.65 (m, 94H)

(Synthesis of compound 7b)
Synthesis was carried out in the same manner as in the synthesis method of compound 7a except that compound 6a was replaced with compound 6b (70 mg, 0.265 mmol) to obtain compound 7b as a dark green solid (70 mg, yield 43%).

The physical property data of the obtained compound 7b are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 8.80 (s, 2H), 8.62 (s, 2H), 7.84 (d, J = 4.0Hz, 2H), 3.04 ( s, 4H) 1.83-1.67 (m, 4H), 1.51-0.55 (m, 104H)

(Synthesis of compound 7c)
Synthesis was carried out in the same manner as in the synthesis method of compound 7a except that compound 5a was replaced with compound 5b (100 mg, 0.08 mmol) to obtain compound 7c as a dark green solid (80 mg, yield 60%).

The physical property data of the obtained compound 7c are as follows.
¹ HNMR (500MH ₂ , CDCl ₃ , TMS) δ = 8.71 (d, J = 4.5Hz, 2H), 8.43-8.35m, 2H), 7.50 (d, J = 7.4Hz) , 2H), 3.05 (s, 4H) 1.77 (d, J = 15.0Hz, 4H), 1.54-1.12 (m, 8H), 1.02-0.58 (m, 74H), 0.49 (s, 6H)

(Synthesis of compound 7d)
The compound 5a was synthesized in the same manner as in the synthesis method of the compound 7a except that the compound 5a was replaced with the compound 5b (80 mg, 0.0641 mmol) and the compound 6a was replaced with the compound 6b (51 mg, 0.192 mmol), and the compound 7d was made into a dark green solid. Obtained (70 mg, 63% yield).

The physical property data of the obtained compound 7d are as follows.
¹ HNMR (400MH ₂ , CDCl ₃ , TMS) δ = 8.78 (s, 2H), 8.59 (d, J = 1.4Hz, 2H), 7.84 (d, J = 4.1Hz, 2H) ), 3.01 (s, J = 7.9Hz, 4H), 1.72 (s, 4H), 1.51-1.09 (m, 12H), 1.02-1.58 (m, 70H) ), 0.47 (s, 6H)

Subsequently, a solar cell element was produced using each of the synthesized compounds 7a-7d, and the photoelectric conversion efficiency was evaluated.

(Manufacturing and evaluation of solar cell element using compound 7a)
After thoroughly cleaning the glass substrate on which the ITO film was patterned, UV ozone treatment was performed. Next, a solution prepared by dissolving 0.5 g of zinc acetate (II) dihydrate and 0.142 mL of ethanolamine in 5 mL of 2-methoxyethanol is spin-coated at 5000 rpm for 30 seconds, and the substrate is heated at 180 ° C. for 30 minutes. Then, the electron extraction layer was formed into a film.
The substrate on which the electron extraction layer is formed is brought into the glove box, and a chlorobenzene solution containing the compound 7a and the polymer compound P1 which is an electron acceptor (compound 7a / weight ratio of the polymer compound P1 = 1.2 / 1) is applied. The photoactive layer was formed by spin coating (thickness: 100 nm). The polymer compound P1 was synthesized and used with reference to "S. Wen et al., Chem. Mater. 2019, 31, 919.".

Further, a 7.5 nm thick molybdenum trioxide (MoO ₃ ) film as a hole extraction layer and a silver film with a thickness of 100 nm as an electrode layer are sequentially formed on the active layer by a resistance heating type vacuum vapor deposition method. Then, a 4 mm square organic thin-film solar cell element was manufactured.

The obtained organic thin-film solar cell was irradiated with constant light using a solar simulator (AM1.5G filter, irradiance 100 mW / cm ² ), and the generated current and voltage were measured. FIG. 1 shows a graph of current density-voltage characteristics, and FIG. 2 shows spectral sensitivity characteristics.

When the short-circuit current density Jsc (mA / cm ² ), open circuit voltage Voc (V), and curve factor FF were obtained from the obtained FIG. 1, Jsc = 15.92mA / cm ² , Voc = 0.94V, FF = 0. It was .57. Further, the photoelectric conversion efficiency (η) was calculated from the formula η = (Jsc × Voc × FF) / 100 and found to be 8.6%.

(Manufacturing and evaluation of solar cell element using compound 7b)
Organic in the same manner as above except that a photoactive layer was formed by spin coating using a chloroform solution containing compound 7b and the polymer compound P1 (compound 7b / weight ratio of the polymer compound P1 = 1.2 / 1). A thin-film solar cell was produced (thickness 100 nm) and its characteristics were evaluated. The current density-voltage characteristics shown in FIG. 3 were obtained, and Jsc = 17.91 mA / cm ² , Voc = 0.90 V, and FF = 0.58. η was 9.3%. Further, FIG. 4 shows the spectral sensitivity characteristics.

(Evaluation of solar cell element using compound 7c)
Organic in the same manner as above except that a photoactive layer was formed by spin coating using a chloroform solution containing compound 7c and the polymer compound P1 (compound 7c / weight ratio of the polymer compound P1 = 1.2 / 1). A thin-film solar cell was produced (thickness 100 nm) and its characteristics were evaluated. The current density-voltage characteristics shown in FIG. 5 were obtained, and Jsc = 17.63 mA / cm ² , Voc = 0.92 V, and FF = 0.61. η was 10.0%. Further, FIG. 6 shows the spectral sensitivity characteristics.

(Evaluation of solar cell element using compound 7d)
Organic in the same manner as above except that a photoactive layer was formed by spin coating using a chloroform solution containing compound 7d and the polymer compound P1 (compound 7d / weight ratio of the polymer compound P1 = 1.2 / 1). A thin-film solar cell was produced (thickness 100 nm) and its characteristics were evaluated. The current density-voltage characteristics shown in FIG. 7 were obtained, and Jsc = 19.08 mA / cm ² , Voc = 0.88 V, and FF = 0.61. η was 10.2%. Further, FIG. 8 shows the spectral sensitivity characteristics.

(Comparative example: Fabrication and evaluation of a solar cell element using compound 8)
A solar cell element was prepared and evaluated using compound 8 which is a commercially available electron donor.

Organic in the same manner as above except that a photoactive layer was formed by spin coating using a chloroform solution containing compound 8 and the polymer compound P1 (compound 8 / weight ratio of the polymer compound P1 = 1 / 1.2). A thin-film solar cell was produced (thickness 100 nm) and its characteristics were evaluated. The current density-voltage characteristics shown in FIG. 9 were obtained, and Jsc = 16.9 mA / cm ² , Voc = 0.85 V, FF = 0.57, and η were 8.3%. Further, FIG. 10 shows the spectral sensitivity characteristics.

Table 2 summarizes the characteristics of the organic thin-film solar cells obtained by using the compounds 7a-7d and the compound 8. It can be seen that the organic thin-film solar cell obtained by using the compound 7a-7d has higher photoelectric conversion efficiency and has good characteristics as compared with the organic thin-film solar cell obtained by using the compound 8.

The low molecular weight compound and the high molecular weight compound according to the present invention can be used as an organic semiconductor material for forming an active layer of an organic semiconductor device such as an organic thin film solar cell or an organic thin film.

Claims (4)

Represented by Equation 1 or Equation 2,

(In Formulas 1 and 2, R represents an alkyl group, A represents a heteroaromatic ring, and B in Formula 2 represents a heterocycle.)
A small molecule compound characterized by that. Including the repeating unit represented by the formula 3 or the formula 4.

(In formulas 3 and 4, R represents an alkyl group, A represents a heteroaromatic ring, Ar represents a heteroaromatic ring, and B in formula 4 represents a heterocycle.)
A polymer compound characterized by this. The small molecule compound according to claim 1 or the high molecular compound according to claim 2 is included.
An organic semiconductor material characterized by this. It has an active layer containing the organic semiconductor material according to claim 3.
An organic semiconductor device characterized by this.

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