JP2009099942A - High molecular organic semiconductor material, high molecular organic semiconductor thin film and organic semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: organic semiconductor material which permits liquefaction; an organic semiconductor film produced by applying organic semiconductor material; and an organic semiconductor device employing the organic semiconductor film. <P>SOLUTION: The organic semiconductor device is configured by using in a semiconductor layer: the polymerized organic semiconductor material constituted by polymerizing a compound shown by the formula 1; the polymerized molecular organic semiconductor material thin film containing the polymerized organic semiconductor material; and the polymerized organic semiconductor material. In the formula (1), R1 and R2 are each independently H or a 1-16C alkyl (provided that the following case is excluded: both R1 and R2 are H), W1 and W2 are each independently H, a halogen atom and at least one group selected from a group consisting of (HO)<SB>2</SB>B- and (R3-O)<SB>2</SB>B-, and R3 is a 1-12C alkyl. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polymer organic semiconductor material, a polymer organic semiconductor material thin film, and an organic semiconductor device.

  With the progress of computerization, the spread of information terminals has been remarkable, and there has been an increase in the chances that information previously provided in paper media has been digitized, and there is a need for mobile information media that is thin, light, and easy to carry. It is growing.

  A semiconductor device using a silicon (Si) material that constitutes a conventional information medium has to repeatedly form a vacuum system including a vacuum chamber over and over again to form each layer. It was huge. For example, in a TFT element which is one of semiconductor devices, it is usually necessary to repeat processes such as vacuum deposition, dope, photolithography, development, etc. many times in order to form each layer. Is formed on the substrate. As for the semiconductor portion that is the key to the switching operation, a plurality of types of semiconductor layers such as p-type and n-type are stacked.

  In addition, since the formation of a semiconductor device using such a conventional Si material includes a process at a high temperature, the substrate material is restricted to be a material that can withstand the process temperature. For this reason, glass must be used in practice, and therefore, the product lacks flexibility and may be broken by a drop impact. This is not desirable in satisfying the need for mobile information media as described above.

  On the other hand, in recent years, research on organic semiconductor materials has been vigorously advanced as an organic compound having charge transportability. These compounds are not only charge transport materials for organic diodes and organic light emitting diodes (EL), but also organic laser oscillation elements (for example, see Non-Patent Document 1) and organic thin film transistors (organic TFT elements) (for example, Non-Patent Documents). 2)) is expected.

  Organic semiconductor materials are the same as organic conductor materials in that they transport charges, but the mechanism of charge transport is greatly different between the two. The difference is that the organic conductor material contains charge carriers that are responsible for charge transport in the material, whereas the organic semiconductor material does not have charge carriers in the material. Therefore, since the organic conductor material has charge carriers, it exhibits a behavior similar to that of a metal, and when incorporated in an electric circuit, it becomes an electric conductor in which the current is simply proportional to the applied voltage. It can only be a simple wiring material. On the other hand, since the organic semiconductor material does not have charge carriers, it is necessary to supply charge carriers from the outside in order to develop charge transport. For this charge carrier supply, a Schottky barrier structure, pn A physical structure such as a junction structure or an MIS structure is created and used. The current of the “organic semiconductor device” composed of the organic semiconductor material and the physical structure thus obtained is controlled by the physical structure and exhibits semiconductor device characteristics that do not follow Ohm's law, as with the Si semiconductor device ( Examples include rectifying characteristics found in diodes, switching characteristics and memory characteristics found in transistors).

  These organic semiconductors have a possibility of obtaining a semiconductor that can be made into a solution by appropriately improving the molecular structure thereof, and the device can be manufactured by a printing method by making the organic semiconductor solution into an ink. The manufacture by these low-temperature processes means that the above-mentioned restrictions on the heat resistance of the substrate are relaxed, and a semiconductor device can be formed on a resin substrate.

  Until now, low molecular weight compounds such as acenes such as pentacene and tetracene (see, for example, Patent Document 1), phthalocyanines including lead phthalocyanine, perylene and its tetracarboxylic acid derivatives have been studied as organic semiconductor materials. For example, see Patent Document 2), aromatic oligomers represented by thiophene hexamers called α-thienyl or sexithiophene (see, for example, Patent Document 3), naphthalene, anthracene and 5-membered aromatics. A compound in which a heterocyclic ring is condensed symmetrically (for example, see Patent Document 4), mono, oligo, and polydithienopyridine (for example, see Patent Document 5), and further, polythiophene, polythienylene vinylene, poly-p-phenylene vinylene. Limited types of compounds such as conjugated polymers such as Reference.) There is.

  Among them, many of low molecular compounds such as pentacene and aromatic oligomers such as α-thienyl have a problem that it is difficult to form a film by coating because they are insoluble or hardly soluble in an organic solvent. This increases the manufacturing cost in manufacturing the semiconductor device, and therefore, the attractiveness as an economical technology replacing the Si-based semiconductor technology is lost.

  On the other hand, a polymer compound such as polythiophene is oxidatively doped with ambient oxygen, increasing the conductivity, that is, unstable to air. Therefore, many of these materials have the problem that strict precautions must be taken to eliminate or minimize oxidative doping by eliminating environmental oxygen during material processing and device fabrication. The above preventive measures increase the manufacturing cost, so that the attractiveness as an economical technology replacing the Si-based semiconductor technology is lost.

On the other hand, recently, a paper on energy level simulation (Non-patent Document 4) has disclosed that poly-thieno [3,4-d] imidazol-2-one (Poly-thieno [3,4-d] imidazolol-2) as a novel thiophene derivative. -One (hereinafter abbreviated as PUT). When actually manufactured, this PUT is an organic conductor material having an electric conductivity of about 10 ⁻¹ to 10 S / cm, and it has been found that it does not function as an organic semiconductor.

Science 2000, No. 289, p. 599 Nature 2000, 403, p. 521 Advanced Material 2002, No. 2, P.I. 99 Journal of Physical Chemistry B 2005, No. 109, p. 3126 JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP-A-11-195790 JP 2003-155289 A

  The problem to be solved by the present invention is to provide an organic semiconductor material that can be made into a solution, an organic semiconductor film obtained by applying the organic semiconductor material, and an organic semiconductor device using the organic semiconductor film.

The present inventors obtain an organic semiconductor material that can be made into a solution by replacing both or one of the hydrogen atoms on the nitrogen of polythieno [3,4-d] imidazol-2-one with an alkyl group. I found out that I can do it.
The reason why the organic conductive material becomes an organic semiconductor material by substituting both or one of the hydrogen atoms with an alkyl group is not clear, but is estimated as follows. That is, it is considered that the energy level of the highest occupied orbital (HOMO) of π electrons decreases and the energy level of the lowest unoccupied orbital (LUMO) increases due to the steric effect by the introduction of the alkyl group. Although charge carriers are not generated, it is presumed that moderate spread of π conjugation in each monomer unit ensures carrier mobility.

  That is, the present invention relates to the general formula (1)

(In formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms (except when R1 and R2 are hydrogen atoms), and W1 and W2 are Each independently represents at least one group selected from the group consisting of a hydrogen atom, a halogen atom, (HO) ₂ B— and (R ₃ —O) ₂ B—, wherein R 3 has 1 to 12 carbon atoms A high molecular weight organic semiconductor material obtained by polymerizing a compound represented by the following formula:

  The present invention also provides a polymer organic semiconductor material thin film containing the polymer organic semiconductor material described above.

  Moreover, this invention provides the organic-semiconductor device which uses the polymeric organic-semiconductor material of the said description for a semiconductor layer.

  The present invention can provide an organic semiconductor material that can be made into a solution, an organic semiconductor film obtained by applying the organic semiconductor material, and an organic semiconductor device using the organic semiconductor film.

(Compound represented by the general formula (1))
In the general formula (1), R 1 and R 2 each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms. However, the case where R1 and R2 are hydrogen atoms is excluded. This is because R1 or R2, that is, when at least one hydrogen atom is an alkyl group, exhibits semiconductor characteristics, but a compound in which R1 and R2 are hydrogen atoms does not exhibit semiconductor characteristics as described above.
Among them, the number of carbon atoms is preferably 1 to 12, and 1 to 6 is most preferable in view of semiconductor characteristics.

In the general formula (1), W1 and W2 are each independently a hydrogen atom, a halogen atom such as chlorine, bromine or iodine, (HO) ₂ B- (boronic acid) and (R3-O) ₂ B—. Represents at least one group selected from the group consisting of (boronic acid esters). Among them, a halogen atom and (R3-O) 2 _B- polymer organic semiconductor material by polymerizing a compound having a preferable in semiconductor characteristics.

  Among the compounds in the general formula (1), compounds in which W1 and W2 are hydrogen atoms can be synthesized by the following scheme.

  Specifically, “Journal of Organic Chemistry” 2002, No. 67, p. In thieno [3,4-d] imidazol-2-one (Poly-thieno [3,4-d] imidazol-2-one) produced by the method described in 9073 under a solvent of dimethylformamide (hereinafter abbreviated as DMF), By allowing alkyl iodide and NaH to act, hydrogen bonded to nitrogen can be alkylated, and by controlling the molar ratio between reactive molecular species, the number of introduced methyl groups can be controlled.

  In the compound represented by the general formula (1), when W1 and W2 are halogen atoms, a compound in which W1 and W2 are hydrogen is used as a starting material as follows, under dimethylformamide (hereinafter abbreviated as DMF), By acting N-bromosuccinimide (hereinafter abbreviated as NBS), it can be obtained as in the following synthesis scheme.

When W1 and W2 are (HO) ₂ B- or (R3-O) ₂ B-, they can be synthesized by the following method. That is, starting from a compound in which W1 and W2 are halogen atoms such as bromine, magnesium is allowed to act under tetrahydrofuran (hereinafter abbreviated as THF), and 2-isopropoxy-4,4,5,5-tetra By adding methyl-1,3,2-dioxaborolane, the following synthesis scheme is obtained.

(Polymer organic semiconductor materials)
The film | membrane formed by superposing | polymerizing the compound represented by General formula (1) of this invention can be obtained by using for electrolytic oxidation polymerization, when W1 and W2 are hydrogen atoms. Electrolytic oxidation polymerization can be performed by a two-electrode method or a three-electrode method. Potential-based polymerization (for example, low-potential polymerization, cyclic potential polymerization), voltage-based polymerization (for example, constant-voltage polymerization), current-based polymerization (for example, Constant current polymerization). In the case of the three-electrode method, a general reference electrode can be used, but a saturated calomel electrode (SCE), a silver / silver chloride electrode (Ag / AgCl), and a silver / silver ion electrode (Ag / Ag ⁺ ) are available. Often used. As the working electrode and the counter electrode, an indium tin oxide (hereinafter abbreviated as ITO) electrode, nesa glass, a platinum plate, a carbon electrode, or the like can be used.
The solvent has a high relative dielectric constant and dissolves the electrolyte well, and two or more kinds of solvents may be mixed. Specific examples of the solvent include acetonitrile, benzonitrile, propylene carbonate, alcohol, dichloromethane, chloroform, 1,2-dichloroethane, acetone, nitromethane, ethyl acetate, THF, pyridine, nitrobenzene, N-methylpyrrolidone, dimethyl sulfoxide, N , N-dimethylformamide, water and the like.
As the supporting electrolyte, a salt, ClO ₄ ⁻ , PF ₆ ⁻ that does not undergo an electrode reaction within the range of the electropolymerization potential (Ag / Ag ⁺ the range of the electrolysis potential +0.5 V to +1.8 V relative to the reference electrode). Metal salts containing anions such as BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , N (CF ₃ SO ₂ ) ₂ ^— and SbF ₆ ^— , onium salts and the like are used.

Specifically, in a solvent solution such as acetonitrile in which W1 and W2 are hydrogen atoms among the compounds represented by the general formula (1) and the supporting electrolyte, a working electrode made of ITO, Ag / A reference electrode made of Ag ⁺ and a counter electrode made of a platinum plate are immersed. When an appropriate voltage is applied to the working electrode with respect to the reference electrode, a polymer of a compound represented by the compound in which W1 and W2 are hydrogen atoms in the general formula (1) is deposited on the working electrode, and the film is formed. It is formed. Next, the reaction of electrolytic polymerization is shown.

The film obtained by the electropolymerization method is generally a colored film in a thickness range of 1 to 1000 nm. Since this film is usually in an oxidized state, an arbitrary range of −0.5 V to −0.0 V with respect to the Ag / Ag ⁺ reference electrode is required to develop a sufficient function as an organic semiconductor material. It is preferable to use after applying a voltage until no reduction current flows. The electrolytic polymerization method is preferable in that the film forming process can be omitted because the film can be directly formed on the working electrode.

In addition, among the compounds represented by the general formula (1), a compound in which W1 and W2 are hydrogen atoms can be polymerized by a solution polymerization method or the like using an oxidizing agent or the like. Specifically, among the compounds represented by the general formula (1), a compound in which W1 and W2 are hydrogen atoms is dissolved in butanol, and the polymerization proceeds by adding an oxidizing agent such as FeCl _3. Precipitates. The obtained polymer is washed with water, then treated with a reducing agent such as hydrazine hydrate, and the desired polymer organic semiconductor material is obtained by repeating washing with water and washing with ethanol.

  Further, among the compounds represented by the general formula (1), a compound in which W1 and W2 are hydrogen atoms is dissolved in an alcohol together with an oxidizing agent, and this solution is applied on a substrate and then heated at 50 to 200 ° C. By doing so, a film can be formed. By treating this film with a reducing agent such as hydrazine hydrate, a film made of a desired polymer organic semiconductor material can be obtained. In this solution, a base such as imidazole or pyridine can be added for the purpose of controlling the reaction rate. There is no restriction | limiting in particular as an application | coating system, A well-known and usual method can be used. Specifically, gravure method, reverse method, air doctor coater method, blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, die method , Spin coater method, bar coater method, reverse printing method, screen coater method and the like. The polymerization method according to this method is preferable in that the film formation process can be omitted because the film formation and the organic semiconductor material are simultaneously synthesized.

  In the case where W1 and W2 are halogen atoms among the compounds represented by the general formula (1), polycondensation is performed using a coupling reagent such as a Ni zerovalent complex as shown in the following reaction formula. Thus, a desired polymer organic semiconductor material can be obtained.

In the case where the compound represented by the general formula (1) is a compound in which W1 and W2 are (R3-O) ₂ B- or (HO) ₂ B-, a Pd complex as shown in the following reaction formula: Can be used as a coupling reagent to obtain a desired polymer organic semiconductor material.

When the polymer organic semiconductor material of the present invention is obtained by polymerizing a compound represented by the general formula (1) in which W1 and W2 are hydrogen atoms, in the infrared absorption spectrum (IR), thiophene The disappearance of the peak derived from hydrogen at the 2nd and 5th positions of the ring (aromatic ring-H in-plane bending vibration) makes it possible to determine that the polymer was formed at the 2nd and 5th positions. On the other hand, when a compound represented by the general formula (1) in which W1 and W2 are halogen atoms or (R3-O) ₂ B- or (HO) ₂ B- is polymerized, a thiophene ring The peak derived from the halogen or boronate ester at positions 2 and 5 (aromatic ring-halogen (boronate ester) in-plane bending vibration) disappeared, and it was determined that the polymer was polymerized at positions 2 and 5 it can. Furthermore, since the polymer organic semiconductor material according to the present invention is very well soluble in a general-purpose solvent, the molecular weight can be specified by a light scattering method or gel permeation chromatography (GPC).

(Polymer organic semiconductor material thin film)
The polymer organic semiconductor material thin film according to the present invention will be described.
The polymeric organic semiconductor material of the present invention can be mixed with an appropriate organic solvent and used as a solution or dispersion.

  When producing a polymer organic semiconductor material thin film using a solution containing the polymer organic semiconductor material of the present invention, any organic solvent may be used, and two or more organic solvents may be mixed. It may be used, but preferably contains at least one non-halogen solvent, and more preferably comprises only non-halogen solvent. Non-halogen solvents used in the present invention include aliphatic solvents such as hexane and octane, alicyclic solvents such as cyclohexane, aromatic solvents such as benzene, toluene and xylene, tetrahydrofuran, dioxane, and ethylene glycol diethyl ether. , Ether solvents such as anisole, benzyl ethyl ether, ethyl phenyl ether, diphenyl ether, and methyl-t-butyl ether, ester solvents such as methyl acetate, ethyl acetate, and ethyl cellosolve, alcohol solvents such as methanol, ethanol, and isopropanol, acetone , Ketone solvents such as methyl ethyl ketone, cyclohexanone, 2-hexanone, 2-heptanone and 3-heptanone, other dimethylformamide, dimethylsulfoxide, diethylformamide, 1,3- Oxolane, and the like.

  Further, the organic solvent used in combination is not particularly limited, but preferred examples include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, pyrrolidone, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, Examples include methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, butyl lactate, methyl β-methoxypropionate, ethyl β-ethoxypropionate, propylene glycol monomethyl ether acetate, toluene, xylene, hexane, limonene, cyclohexane, etc. It is done. Two or more of these organic solvents can be used in combination.

  Further, as the ester solvent, oxyisobutyric acid alkyl ester or the like may be used, and as oxyisobutyric acid ester, α-methoxyisobutyrate methyl, α-methoxyisobutyrate ethyl, α-ethoxyisobutyrate methyl, α-ethoxyisobutyrate ethyl, etc. α-alkoxyisobutyric acid alkyl esters; β-alkoxyisobutyric acid alkyl esters such as methyl β-methoxyisobutyrate, ethyl β-methoxyisobutyrate, methyl β-ethoxyisobutyrate, ethyl β-ethoxyisobutyrate; and methyl α-hydroxyisobutyrate, α Α-hydroxyisobutyric acid alkyl esters such as ethyl-hydroxyisobutyrate, and in particular, methyl α-methoxyisobutyrate, methyl β-methoxyisobutyrate, methyl β-ethoxyisobutyrate or methyl α-hydroxyisobutyrate may be used. it can.

The polymer organic semiconductor material thin film of the present invention is preferably produced through a step of forming a film using a solution or a dispersion at room temperature, prepared by mixing the organic semiconductor material of the present invention with the organic solvent. Here, the solution or dispersion at room temperature preferably forms a solution or dispersion when the organic semiconductor material and the organic solvent are mixed under conditions of 10 ° C. to 80 ° C. The state in which the organic semiconductor material is dispersed in a particulate form is shown, but the state in which the organic semiconductor material is partially dissolved in the dispersion is also included.
Further, as one embodiment of the dispersion, for example, it dissolves under a temperature condition of 80 ° C. to form a solution, but when returned to room temperature (usually showing a temperature of about 25 ° C.), particles or aggregates of organic semiconductor material And a state in which precipitates are dispersed in an organic solvent.

  There is no restriction | limiting in particular as an application | coating system, A well-known and usual method can be used. Specifically, gravure method, reverse method, air doctor coater method, blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, die method , Spin coater method, bar coater method, reverse printing method, screen coater and the like.

(Organic semiconductor device)
The organic semiconductor device of the present invention will be described.
When the polymer organic semiconductor material of the present invention is used as a polymer organic semiconductor film in a semiconductor layer such as an organic semiconductor device, it can provide an organic semiconductor device, an organic diode, and the like that are driven well.

  An organic diode simply has a sandwich structure in which an electrode, an organic semiconductor thin film, and an electrode are laminated in this order on a substrate (see FIG. 1).

  In the present invention, the material for forming the electrode is not particularly limited as long as it is a conductive material. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, Iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, tin oxide / antimony, indium tin oxide (ITO), fluorine-doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium, beryllium, sodium , Magnesium, potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloy, magnesium, lithium, aluminum, magnesium / copper mixture, magnesium / silver mixture Things, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, lithium / aluminum mixture, etc. are used, in particular, platinum, gold, silver, copper, aluminum, indium, ITO and carbon are preferable. Alternatively, known conductive polymers whose conductivity is improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, conductive polythiophene, a complex of polyethylenedioxythiophene and polystyrenesulfonic acid, and the like are also preferably used.

  As a method for forming an electrode, a method for forming an electrode using a known photolithographic method or a lift-off method, using a conductive thin film formed by a method such as vapor deposition or sputtering using the above as a raw material, or a metal foil such as aluminum or copper There is a method of etching using a resist by thermal transfer, ink jet or the like. Alternatively, a conductive polymer solution or dispersion, or a conductive fine particle dispersion may be directly patterned by ink jetting, or may be formed from a coating film by lithography or laser ablation. Furthermore, a method of patterning an ink containing a conductive polymer or conductive fine particles, a conductive paste, or the like by a printing method such as relief printing, intaglio printing, planographic printing, or screen printing can also be used.

  Further, the substrate is made of glass or a flexible resin sheet, and for example, a plastic film can be used as the sheet. Examples of the plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC). And a film made of cellulose triacetate (TAC), cellulose acetate propionate (CAP), or the like. Thus, by using a plastic film, the weight can be reduced as compared with the case of using a glass substrate, the portability can be improved, and the resistance to impact can be improved.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. Here, regarding the number average molecular weight and the weight average molecular weight, the number average molecular weight in terms of polystyrene was determined by gel permeation chromatography (GPC) (manufactured by Shimadzu Corporation: LC-10Avp) using tetrahydrofuran as a solvent.
Unless otherwise specified, “%” is based on mass.

（Ａ）
４００ｍＬの濃硫酸、６００ｍＬの発煙濃硫酸、及び３２５ｍＬの濃硝酸よりなる室温下の混酸に、３５０ｇの２，５−ジブロモチオフェン（アルドリッチ製）を反応液の温度を２０〜３０℃に維持しながら滴下した。滴下後、反応溶液に氷水を加え、析出した粉末を濾別し、メタノールより再結晶することで、２，５−ジブロモ−３，４−ジニトロチオフェン１４４ｇを得た。 (Synthesis Example 1 Synthesis of Compound Represented by Formula (A))

(A)
350 g of 2,5-dibromothiophene (manufactured by Aldrich) was added to a mixed acid at room temperature consisting of 400 mL of concentrated sulfuric acid, 600 mL of fuming concentrated sulfuric acid, and 325 mL of concentrated nitric acid while maintaining the temperature of the reaction solution at 20-30 ° C. It was dripped. After dropping, ice water was added to the reaction solution, and the precipitated powder was filtered off and recrystallized from methanol to obtain 144 g of 2,5-dibromo-3,4-dinitrothiophene.

30 g of palladium chloride was reduced with hydrogen under 1.4 × 10 ⁵ Pa in a mixed solvent consisting of 300 mL of methanol and 300 mL of water. Next, 7.5 mL of concentrated sulfuric acid and 10 g of 2,5-dibromo-3,4-dinitrothiophene were added in this order, and the mixture was stirred for 1 hour 30 minutes under 1.4 × 10 ⁵ Pa of hydrogen. The reaction solution was filtered, 200 mL of methanol was added to the filtrate and stirred well, and then concentrated under reduced pressure to obtain an acidic aqueous solution of 3,4-diaminothiophene.

Sodium carbonate and phosgene were allowed to act on the obtained acidic aqueous solution of 3,4-diaminothiophene for 1 hour, followed by concentration under reduced pressure. The obtained solid was purified by sublimation at 125 ° C. to 150 ° C. under 10 ⁻⁴ Pa, and then recrystallized from a methanol / ethanol (1/1 = volume / volume) mixed solvent to obtain 0.35 g of compound “UT” ( 50% yield from 2,5-dibromo-3,4-dinitrothiophene).

Under an argon stream, 9.6 g of “UT” and 4 g of NaH were added in this order to 310 mL of DMF, and 40 mL of DMF solution in which 24.4 g of MeI was dissolved was added dropwise over 20 minutes, and then the reaction solution was added for 5 hours. Stir. The reaction was stopped by adding 30 mL of water, 200 g of ice was added, and the mixture was stirred until the ice thawed. After extraction with ethyl acetate, the organic layer was washed with 30% brine, dried over magnesium sulfate, and concentrated. The concentrate thus obtained was purified using column chromatography (carrier: silica gel, developing solvent: ethyl acetate / dichloromethane = 1/1 = volume / volume), and the compound “DMUT” represented by the formula (A) Was obtained as a white powder (7 g, 61% yield from 2,5-dibromo-3,4-dinitrothiophene).

(Synthesis Example 2 Synthesis of Compound Represented by Formula (B))

（Ｂ）

(B)

  Under argon flow, 2.6 g of NaH and 9.6 g of “UT” obtained in Synthesis Example 1 were added in this order to 250 mL of DMF, and 50 mL of DMF solution in which 15.2 g of MeI was dissolved was gradually added dropwise to room temperature. For 3 hours. The reaction was stopped by adding 30 mL of water, and after extracting with ethyl acetate, the resulting solid was recrystallized three times from a tetrahydrofuran / methanol mixed solvent to obtain the compound “MMUT” represented by the formula (B) as a white powder. (0.56 g, 5% yield from 2,5-dibromo-3,4-dinitrothiophene).

(Synthesis Example 3 Synthesis of Compound Represented by Formula (C))

（Ｃ）

(C)

  The compound “DPUT” represented by the formula (C) was obtained as a needle-like crystal in the same manner as in Synthesis Example 1 except that 24.4 g of MeI of Synthesis Example 1 was changed to 26.0 g of pentyl bromide (8 g, 42% yield from 2,5-dibromo-3,4-dinitrothiophene).

(Synthesis Example 4 Synthesis of Compound Represented by Formula (D))

（Ｄ）

(D)

The compound “MPUT” represented by the formula (D) was obtained as a yellow liquid in the same manner as in Synthesis Example 2 except that 15.2 g of MeI of Synthesis Example 2 was changed to 16.0 g of pentyl bromide (1.1 g , 7% yield from 2,5-dibromo-3,4-dinitrothiophene).

(Synthesis Example 5 Synthesis of Compound Represented by Formula (E))

（Ｅ）

(E)

  6.6 g of “DMUT” obtained in Synthesis Example 1 was dissolved in 60 mL of DMF, and this was cooled using an ice bath. A solution consisting of 15.5 g of N-bromosuccinic imide (NBS) and 60 mL of DMF was added dropwise thereto. After completion of the dropwise addition, 10 mL of DMF was added and stirred at room temperature for 1 hour. Thereafter, the reaction solution was poured into ice water, the obtained powder was filtered off, washed with 500 mL of water and 10 mL of ethanol, and then vacuum-dried, whereby the compound “DBr-DMUT” represented by the formula (E) was obtained. Was obtained as a pale yellow powder (10 g, 82% yield).

(Reference Example 1 Production of polymer compound “PUT” obtained by polymerizing “UT”)
An electrolytic solution was prepared by dissolving 0.875 g of tetrabutylammonium perchlorate and 0.073 g of “UT” obtained in Synthesis Example 1 in 31 g of acetonitrile. This was put in an electrolytic cell equipped with ITO electrode glass (1.5 × 7 cm = 10.5 cm ² ) as a working electrode and a counter electrode, and Ag / Ag ⁺ as a reference electrode, and an electrochemical analyzer model manufactured by ALS at room temperature. Using 760B, electrolytic polymerization was performed for 2 minutes at an electrolytic potential of 1.3 V (potential with respect to Ag / Ag ⁺ , the same applies hereinafter), and then −0.8 V was applied for 2 minutes. A film made of a transparent polymer compound with blue color was formed. The membrane was removed from the electrode and dried using a vacuum line. As a result, the infrared absorption spectrum of the polymer compound showed the following absorption.

1693 s, 1480 s, 1428 s, 1324 s, 1221 s, 1100 s, 1043 m, 720-600 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively).

The disappearance of the 1158 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at the 2nd and 5th positions of the thiophene ring confirmed that the polymer was polymerized at the 2nd and 5th positions.
All of the above measurement results are in KBr pellets. Accordingly, the membrane was confirmed to be a polymer “PUT” of “UT”.

(Reference Example 2 Production of polymer compound “PUT” obtained by polymerizing “UT”)
1.3 g of imidazole, 1.4 g of “UT” and 10 g of butanol are mixed, and this is added to a mixed solution composed of 11.5 g of iron (III) p-toluenesulfonate and 10 g of butanol, and is stirred and mixed. Spin coat on top (1000 rpm, 30 seconds). After spin coating, the film was heated at 120 ° C. for 2 minutes, rinsed with methanol and hydrazine hydrate, and dried to obtain a film made of a polymer compound. The film was taken out from the glass substrate and dried using a vacuum line. As a result, the infrared absorption spectrum of the polymer compound showed the following absorption.

1693 s, 1480 s, 1428 s, 1324 s, 1221 s, 1100 s, 1043 m, 720-600 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively).

The disappearance of the 1158 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at the 2nd and 5th positions of the thiophene ring confirmed that the polymer was polymerized at the 2nd and 5th positions.
All of the above measurement results are in KBr pellets. Accordingly, the membrane was confirmed to be a polymer “PUT” of “UT”.

Example 1
In Reference Example 1, the compound “DMUT” represented by the formula (A) obtained in Synthesis Example 1 was used instead of the compound “UT”. A colored transparent film was obtained. The membrane was removed from the electrode and dried using a vacuum line. The infrared absorption spectrum of the film showed the following absorption.

1727 s, 1561 m, 1451 s, 1382 s, 1256 m, 1072 s, 985 m, 807 m, 743 m, 622 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively. )

All of the above measurement results are in KBr pellets. The disappearance of the 1152 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the film was a polymer “PDMUT” of the compound represented by the formula (A).
The number average molecular weight in terms of polystyrene of the obtained “PDMUT” was 7.5 × 10 ³ .

(Example 2)
In Reference Example 2, the compound “DMUT” represented by the formula (A) obtained in Synthesis Example 1 was used in place of the compound “UT” in the same manner as in Reference Example 2 except that an orange color was formed on the glass substrate. A film having such transparency was obtained. The membrane was removed from the electrode and dried using a vacuum line. The infrared absorption spectrum of the film showed the following absorption.

1727 s, 1561 m, 1451 s, 1382 s, 1256 m, 1072 s, 985 m, 807 m, 743 m, 622 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively. )

All of the above measurement results are in KBr pellets. The disappearance of the 1152 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the film was a polymer “PDMUT” of the compound represented by the formula (A).
The number average molecular weight in terms of polystyrene of the obtained “PDMUT” was 5.5 × 10 ³ .

(Example 3)
11 g of iron (III) chloride was dissolved in 1 L of acetonitrile, and a dispersion obtained by mixing 2.8 g of the compound “DMUT” represented by the formula (A) obtained in Synthesis Example 1 and 100 mL of acetonitrile was added dropwise thereto. After stirring at room temperature for 15 hours, the reaction solution was separated by filtration to obtain a black powder. This powder was washed with hydrazine hydrate, ethanol and pure water, dissolved in chloroform, and reprecipitated using methanol. The reprecipitate thus obtained was washed again with water and ethanol, and dried using a vacuum line to obtain a pale yellow powder. The infrared absorption spectrum of this powder showed the following absorption.

1727 s, 1561 m, 1451 s, 1382 s, 1256 m, 1072 s, 985 m, 807 m, 743 m, 622 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively. )

All of the above measurement results are in KBr pellets. The disappearance of the 1152 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the powder was a polymer “PDMUT” of the compound represented by the formula (A).
The number average molecular weight in terms of polystyrene of the obtained “PDMUT” was 3.0 × 10 ³ .

Example 4
Under argon gas, 490 mg of Ni (COD) ₂ was added to 6 mL of DMF, and 289 mg of bipyridine and 163 mg of cyclooctadiene were added thereto. To this, 502 mg of the compound “DBr-DMUT” represented by the formula (E) obtained in Synthesis Example 5 was added and stirred at 60 ° C. for 15 hours. Thereafter, the reaction solution was poured into ice water, and the solid powder was separated by filtration. This powder was washed with a 1: 1 mixture of methanol and hydrochloric acid, ethanol and toluene, dissolved in chloroform, and reprecipitated with methanol. The reprecipitate thus obtained was washed again with water and ethanol, and dried using a vacuum line to obtain a pale yellow powder.
The infrared absorption spectrum of this powder showed the following absorption.

1727 s, 1561 m, 1451 s, 1382 s, 1256 m, 1072 s, 985 m, 807 m, 743 m, 622 m, 576 m (numbers indicate absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively. )

All of the above measurement results are in KBr pellets. The disappearance of the 1100 peak (aromatic ring-bromine in-plane bending vibration) derived from bromine at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the powder was a polymer “PDMUT” of the compound represented by the formula (A).
The number average molecular weight in terms of polystyrene of the obtained “PDMUT” was 4.0 × 10 ³ .

(Example 5)
In Example 1, the compound “MMUT” represented by the formula (B) obtained in Synthesis Example 2 was used instead of the compound DMUT represented by the formula (A). A transparent film having a slight yellow color on the electrode was obtained. The membrane was removed from the electrode and dried using a vacuum line. The infrared absorption spectrum of the film showed the following absorption.

1682 s, 1450 s, 1418 s, 1290 s, 1216 s, 1099 s, 1048 m, 720-600 m, 580 m (numbers indicate the absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively).

All of the above measurement results are in KBr pellets. The disappearance of the 1152 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the film was a polymer “PMMUT” of the compound represented by the formula (B).

(Example 6)
In Example 1, the same operation as in Example 1 was carried out except that the compound “DPUT” represented by the formula (C) obtained in Synthesis Example 3 was used instead of the compound DMUT represented by the formula (A). A transparent film having a slight yellow color on the electrode was obtained. The membrane was removed from the electrode and dried using a vacuum line. The infrared absorption spectrum of the film showed the following absorption.

1713 s, 1553 s, 1452 s, 1396 s, 1360 s, 1103 s, 839 s, 750-600 m (numbers indicate the absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively).

All of the above measurement results are in KBr pellets. The disappearance of the 1150 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the film was a polymer “PDPUT” of the compound represented by the formula (C).

(Example 7)
In Example 1, the same procedure as in Example 1 was carried out except that the compound “MPUT” represented by the formula (D) obtained in Synthesis Example 4 was used instead of the compound DMUT represented by the formula (A). A transparent film having a slight yellow color on the electrode was obtained. The membrane was removed from the electrode and dried using a vacuum line. The infrared absorption spectrum of the film showed the following absorption.

1717 s, 1692 s, 1551 s, 1450 s, 1389 s, 1169 s, 750-600 m (the numbers indicate the absorption positions indicated by cm ⁻¹ , m and s indicate intermediate absorption and strong absorption, respectively).

All of the above measurement results are in KBr pellets. The disappearance of the 1088 peak (aromatic ring-H in-plane bending vibration) derived from hydrogen at positions 2 and 5 of the thiophene ring confirmed that the polymer was polymerized at positions 2 and 5.
Therefore, it was confirmed that the film was a polymer “PPMUT” of the compound represented by the formula (D).

(Example 8 organic semiconductor device evaluation)
Using a toluene solution prepared so that the “PDMUT” obtained in Example 4 was 1.5 wt% on a glass substrate on which an ITO film having a thickness of 100 nm was formed by sputtering, spin coating was performed at a rotational speed of 1500 rpm. Filmed. Next, after drying at 80 ° C. for 1 hour under reduced pressure, about 30 nm of aluminum was evaporated as a counter electrode to produce a diode element. It was found that when a voltage was applied to the obtained element, the element exhibited a rectifying action (see FIG. 2), that is, exhibited semiconductor characteristics.

(Example 9 organic semiconductor device evaluation)
“PDMUT” was formed by the method described in Example 2 on a glass substrate on which an ITO film having a thickness of 100 nm was formed by sputtering. Next, after drying at 80 ° C. for 1 hour under reduced pressure, about 30 nm of aluminum was evaporated as a counter electrode to produce a diode element. It was found that when a voltage was applied to the obtained element, the element exhibited a rectifying action (see FIG. 2), that is, exhibited semiconductor characteristics.

(Comparative example 1 organic semiconductor device evaluation)
A device was fabricated in the same manner as in Example 9 except that the “PUT” film was used in the method described in Reference Example 2. The resulting device showed an ohmic behavior rather than a rectifying action (see FIG. 3). This indicates that “PUT” does not exhibit semiconductor properties.

It is a figure which shows the structural example of the organic diode which is a specific aspect of the organic-semiconductor device which concerns on this invention. It is a result of the semiconductor characteristic of the polymer organic semiconductor device of an Example. It is a result of the current-voltage characteristic of a comparative example device.

Explanation of symbols

1: Base material 2: Electrode 3: Organic semiconductor thin film 4: Electrode

Claims (3)

General formula (1)

(In formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms (except when R1 and R2 are hydrogen atoms), and W1 and W2 are Each independently represents at least one group selected from the group consisting of a hydrogen atom, a halogen atom, (HO) ₂ B— and (R ₃ —O) ₂ B—, wherein R 3 has 1 to 12 carbon atoms A high molecular organic semiconductor material obtained by polymerizing a compound represented by the following formula: A polymer organic semiconductor material thin film comprising the polymer organic semiconductor material according to claim 1. An organic semiconductor device comprising the polymer organic semiconductor material according to claim 1 as a semiconductor layer.

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