JP2006114701A - Organic semiconductor material and electronic device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor material having a solubility to a solvent so that a semiconductor layer can be formed from a liquid phase and composed of a polymer or an oligomer displaying high carrier mobility and on-off ratio and an electronic device using the organic semiconductor material. <P>SOLUTION: The organic semiconductor material is composed of the polymer or the oligomer having a structure displayed by general formula (1). The organic semiconductor material has the solubility to the solvent, and displays comparatively high carrier mobility and on-off ratio. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic semiconductor material having FET characteristics and an electronic device using the same, and in particular, an organic semiconductor material composed of a polymer or oligomer composed of a repeating unit containing thiophene and a silicon atom in the main chain, and the use thereof The electronic device.

  Conventionally, field-effect transistors (FETs) using an inorganic semiconductor material such as silicon (Si) as a semiconductor layer have been widely used. Recently, however, field-effect transistors using organic semiconductor materials have been used. It has been actively studied.

  The advantage of using an organic semiconductor material as a semiconductor layer of a field effect transistor is that a process can be performed at a low temperature compared to the case of using an inorganic semiconductor material. It is possible to provide a device having flexibility. In addition, if an organic semiconductor material capable of forming a semiconductor film in a liquid phase is used, a complicated process under vacuum such as vapor deposition or CVD is not required for forming a semiconductor layer. Manufacturing cost can be reduced. Furthermore, the process using coating or printing is suitable for manufacturing a large area device.

As such an organic semiconductor material, for example, poly (3-alkylthiophene) has been reported as having a relatively high carrier mobility (μ) and being soluble in a solvent (for example, non-patent literature). (See 1)
On the other hand, the present inventors have developed a method for synthesizing a silicon-based polymer containing thiophene and a silicon atom in the main chain, and have reported on photoconductivity and hole transportability in an EL device. (For example, refer nonpatent literature 2, patent documents 1 and 2.).
JP 2000-143812 (published on May 26, 2000) JP 2000-351836 A (released on December 19, 2000) Bao, Z., Dodabalapur, A., Lovinger, AJ, Appl. Phys. Lett. 69 (26), 1996: 4108-4110 Ohshita, J., Yoshimoto, K., Hashimoto, M., Hamamoto, D., Kunai, A., Harima, Y., Kunugi, Y., Yamashita, K., Kakimoto, M., Ishikawa, M., J.Organomet.Chem.665 (2003) 29-32

  However, studies on silicon polymers containing thiophene and silicon atoms in the main chain have been limited to photoconductivity, and application to field effect transistors has not been studied. A silicon-based polymer containing a thiophene and a silicon atom in the main chain can be easily synthesized and improved in solubility in a solvent by containing a silicon atom in the main chain. Furthermore, it is expected that the hole transportability is improved by the interaction of silicon atoms with the π-electron system. Therefore, if a silicon-based polymer can be applied to an electronic device such as a field effect transistor, it becomes a very useful organic semiconductor material.

  In addition, the organic semiconductor material has the advantages described above that are not found in the inorganic semiconductor material. However, in order to make full use of the advantages of the organic semiconductor material as described above, the semiconductor layer (semiconductor film) from the liquid phase has solubility in a solvent so that it can be formed, and is high. An organic semiconductor material exhibiting carrier mobility and on / off ratio is desired. However, many organic semiconductor materials that exhibit relatively high carrier mobility and on / off ratio require vacuum deposition, exhibit relatively good FET characteristics, and are capable of forming a semiconductor layer from a liquid phase. Semiconductor materials are limited.

  The present invention has been made in view of the above problems, and an object of the present invention is a polymer or oligomer containing thiophene and silicon atoms in the main chain, which can form a semiconductor layer in a liquid phase. Thus, an organic semiconductor material composed of a polymer or an oligomer having solubility in a solvent and having a relatively high carrier mobility and on / off ratio, and an electronic device using the same are provided.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific polymer or oligomer having thiophene and silicon atoms in the main chain exhibits FET characteristics, and substitution of silicon atoms or thiophenes. By devising the group, it has been found that it has good solubility in a solvent and is useful as an organic semiconductor material, and the present invention has been completed.

  That is, the organic semiconductor material according to the present invention has the general formula (1) or (2) to solve the above problems.

(In (1) and (2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group, and R ³ , R ⁴ , R ⁵ and R ⁶ independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group, n represents an integer of 2 or more, and X represents an integer of 5 or more. It is characterized by comprising a polymer or oligomer having a structure. In the organic semiconductor material according to the present invention, the polymer or oligomer preferably has a carrier mobility (μ) of 1 × 10 ⁻⁶ cm ² / Vs or more and an on / off ratio of 10 or more.

  According to said structure, the said organic-semiconductor material can be applied to a field effect transistor, and the field-effect transistor which utilized the advantage of organic-semiconductor material can be provided.

  In the organic semiconductor material for a field effect transistor according to the present invention, X is preferably 10-14.

  When X is 10 to 14, the organic semiconductor material has an effect of exhibiting higher FET characteristics. Further, since the effect of improving the FET characteristics by making the thiophene unit longer than X = 14 becomes small, it is not necessary to make the thiophene unit longer, and the monomer can be synthesized easily and quickly.

In the organic semiconductor material for a field effect transistor according to the present invention, in the general formulas (1) and (2), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl having 1 to 8 carbon atoms. It is preferably a group, an alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 1 to 8 carbon atoms, an alkynyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

  According to said structure, since the said organic semiconductor has the solubility with respect to an organic solvent, when applying to a field effect transistor, the process in liquid phases, such as a spin coat and a solution casting, becomes possible.

  In the organic semiconductor material for a field effect transistor according to the present invention, the organic semiconductor preferably has n of 2 to 1000 in the general formulas (1) and (2).

  According to said structure, there exists an effect that the said organic semiconductor shows FET characteristic.

  An electronic device according to the present invention is an electronic device having a semiconductor layer and two or more electrodes, wherein the semiconductor layer includes the organic semiconductor material described above. The electronic device is preferably a switching element, and more preferably a field effect transistor.

  A field effect transistor according to the present invention includes a source electrode, a drain electrode, a channel disposed between the source electrode and the drain electrode, and a gate electrode directly or indirectly in contact with the channel. In a field effect transistor that controls a current flowing between a source electrode and a drain electrode by changing a voltage applied to the gate electrode, a semiconductor layer constituting the channel includes the organic semiconductor material described above. Yes.

  According to said structure, the electronic device concerning this invention, Preferably a switching element, More preferably, a field effect transistor has the advantage by using organic-semiconductor material, such as flexibility, compatibility with a plastics, suppression of manufacturing cost. It becomes possible to have.

  As described above, the organic semiconductor material according to the present invention has a configuration that is a polymer or an oligomer having a structure represented by the general formula (1) or (2), and thus has FET characteristics and an electrolytic effect. It can be used for an electronic device such as a transistor.

  In addition, an electronic device according to the present invention is an electronic device having a semiconductor layer and two or more electrodes, and since the semiconductor layer has a configuration including the organic semiconductor material described above, it is lightweight and flexible. In addition, it is possible to provide a device that takes advantage of organic semiconductor materials such as provision of an electronic device that is resistant to impact, suppression of manufacturing cost by forming a semiconductor layer in a liquid phase, and application to a large area device.

  An embodiment of the present invention will be described below with reference to FIGS.

(I) Organic semiconductor material according to the present invention The organic semiconductor material according to the present invention has a general formula (1) or (2)

If it is a polymer or an oligomer which has a structure represented by this, it will not specifically limit.

In general formulas (1) and (2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. That is, the 3-position and 4-position of the thienylene group may be unsubstituted or substituted with an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. In the thienylene chain in which X thienylene groups are bonded, R ¹ and R ² of each thienylene group may be different for each thienylene group. Moreover, the ratio of the substituted hydrogen atom is not particularly limited. For example, the 3-position and 4-position hydrogen atoms of the thienylene group are preferably substituted at a rate of one hydrogen atom per 0.5 to 10 thienylene groups, one per 2 to 6 thienylene groups. More preferably, it is substituted at a ratio of Further, the position where the hydrogen atom is substituted in the oligothienylene chain is not particularly limited, but is preferably substituted at an equal interval.

  Here, the alkyl group, alkenyl group, and alkynyl group are preferably linear or branched having 1 to 8 carbon atoms. The alkoxyl group is preferably linear or branched having 1 to 8 carbon atoms, and the aryl group preferably has 6 to 10 carbon atoms. Thereby, while being able to improve the solubility with respect to a solvent, hole transport property can be improved.

  Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and heptyl. Group, octyl group and the like can be mentioned, but the alkyl group having 1 to 8 carbon atoms is of course not limited thereto. Examples of the alkenyl group having 1 to 8 carbon atoms include vinyl group, allyl group, isopropenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, etc. Of course, the alkenyl groups of -8 are not limited thereto. Examples of the alkynyl group having 1 to 8 carbon atoms include an ethynyl group, propynyl, butynyl group, pentynyl group, hexynyl group, heptynyl group, octynyl group, etc., and an alkynyl group having 1 to 8 carbon atoms. Of course, it is not limited to these. Examples of the alkoxyl group having 1 to 8 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. Group, heptyloxy group, octyloxy group and the like can be mentioned. Of course, the alkoxy group having 1 to 8 carbon atoms is not limited to these. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Of course, an aryl group having 6 to 10 carbon atoms is not limited thereto. Absent.

In general formula (1), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. Even if R ³ and R ⁴ are both hydrogen atoms, the polymer or oligomer exhibits FET characteristics, but at least one hydrogen atom of R ³ and R ⁴ is an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, Or it is preferably an aryl group. Thereby, the solubility with respect to the solvent of the polymer or oligomer represented by General formula (1) can be improved. Here, the alkyl group, alkenyl group, alkynyl group, alkoxyl group may be linear or branched, and preferably has 1 to 8 carbon atoms, and 2-8. Is more preferable, and it is further more preferable that it is 2-6. When the number of carbon atoms is 8 or less, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (1) from being deteriorated because the substituent is large. Moreover, since the solubility to the solvent of the polymer or oligomer represented by General formula (1) will worsen when there are too few carbon numbers, it is preferable that it is 2 or more, but it receives to the influence of the surrounding substituent, for example, When R ³ and R ⁴ are both substituted, the other carbon number is 4 or more, or when the substituted R ¹ and R ² have a large number of carbon atoms, the carbon number is 1. Also shows solubility in solvents. The aryl group preferably has 6 to 10 carbon atoms. When the number of carbon atoms is 10 or less, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (1) from being deteriorated because the substituent is large. R ³ and R ⁴ are more preferably a linear alkyl group or a linear alkoxyl group, preferably having 1 to 8 carbon atoms, more preferably 2 to 8 carbon atoms, More preferably, it is 2-6.

In the general formula (2), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group or an aryl group. Even though R ³ , R ⁴ , R ⁵ and R ⁶ are all hydrogen atoms, the polymer or oligomer exhibits FET characteristics, but at least one silicon atom bonding group for each silicon atom is an alkyl group, an alkenyl group, An alkynyl group, an alkoxyl group, or an aryl group is preferable. Thereby, the solubility with respect to the solvent of the polymer or oligomer represented by General formula (2) can be improved. Here, the alkyl group, alkenyl group, alkynyl group, alkoxyl group may be linear or branched, and preferably has 1 to 8 carbon atoms, and 2-8. Is more preferable, and it is further more preferable that it is 2-6. When the number of carbon atoms is 8 or less, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (2) from being deteriorated due to a large substituent. Moreover, since the solubility to the solvent of the polymer or oligomer represented by General formula (2) will worsen when there are too few carbon numbers, it is preferable that it is 2 or more, but it receives to the influence of the surrounding substituent, for example, When the carbon number of R ³ , R ⁴ , R ^5, and R ⁶ is substituted is 4 or more, or when R ¹ and R ² that are substituted have a large number of carbon atoms Shows solubility in a solvent even if the number of carbon atoms is one. The aryl group preferably has 6 to 10 carbon atoms. When the number of carbon atoms is 10 or less, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (2) from being deteriorated because the substituent is large. R ³ , R ⁴ , R ⁵ and R ⁶ are more preferably a linear alkyl group or a linear alkoxyl group, and the carbon number is preferably 1 to 8, preferably 2 to 8. More preferably, it is more preferably 2-6.

  In general formulas (1) and (2), the value of X is preferably 5-20. The polymer or oligomer exhibits good FET characteristics in this range. Among these, X is more preferably 10-14, and further preferably 12-14. When the X is 10 to 14, the organic semiconductor material exhibits higher FET characteristics, and when the X is 12 to 14, the organic semiconductor material exhibits further higher FET characteristics. Further, since the effect of improving the FET characteristics by making the thiophene chain longer than X = 14 is reduced, it is not necessary to make the thiophene chain longer, and the monomer can be synthesized easily and quickly.

As described above, the polymer or oligomer having the structure represented by the general formula (1) or (2) has FET characteristics. Here, “having FET characteristics” means that a significant on / off ratio can be measured. The FET characteristics are mainly determined by the carrier mobility (μ) of the semiconductor layer and the on / off ratio. The larger the carrier mobility and the on / off ratio, the better the FET characteristics. The polymer or oligomer preferably has a carrier mobility of 1 × 10 ⁻⁶ cm ² / Vs or more, and more preferably 1 × 10 ⁻⁵ cm ² / Vs or more. The on / off ratio is preferably 10 or more, more preferably 100 or more, and further preferably 1000 or more. By using an organic semiconductor material composed of such a polymer or oligomer, it is possible to provide an electronic device having various advantages of the organic semiconductor material.

  Further, the substance having the structure represented by the general formula (1) or (2) may be an oligomer having a relatively small molecular weight or a polymer having a large molecular weight, and a preferable molecular weight range is 1000 to 100,000. It is. Therefore, in the general formulas (1) and (2), the value of n may be a value corresponding to the molecular weight. Thus, the value of n may be in a relatively wide range and is preferably 2 to 1000, more preferably 2 to 100, and still more preferably 3 to 10.

(II) Manufacturing method of organic semiconductor material The manufacturing method of the organic semiconductor concerning this invention which consists of said polymer or oligomer is not specifically limited, It is compoundable by a conventionally well-known method. For example, as a specific example of a method for producing a polymer or oligomer having a structure represented by the general formula (1), as shown in the following reaction formula (3), a bis (halogenated thienyl) silane compound, The method of synthesize | combining by making both ends trialkylstannyl thiophene or both ends trialkylstannyl oligothiophene react in presence of a catalyst can be mentioned.

In the above reaction formula (3), R ¹ , R ² , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. . That is, the 3-position and 4-position of the thienylene group may be unsubstituted or substituted with an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. Moreover, the ratio of the substituted hydrogen atom is not particularly limited. For example, the 3-position and 4-position hydrogen atoms of the thienylene group are preferably substituted at a rate of one hydrogen atom per 0.5 to 10 thienylene groups, one per 2 to 6 thienylene groups. More preferably, it is substituted at a ratio of Further, the position where the hydrogen atom is substituted in the oligothienylene chain is not particularly limited, but is preferably substituted at an equal interval.

  Here, the alkyl group, alkenyl group, and alkynyl group are preferably linear or branched having 1 to 8 carbon atoms. The alkoxyl group is preferably linear or branched having 1 to 8 carbon atoms, and the aryl group is preferably linear or branched having 6 to 10 carbon atoms.

In the reaction formula (3), R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group. Even if R ³ and R ⁴ are both hydrogen atoms, the polymer or oligomer exhibits FET characteristics, but at least one of R ³ and R ⁴ is an alkyl group, alkenyl group, alkynyl group, alkoxyl group, or aryl group. It is preferably substituted with. Thereby, the solubility with respect to a solvent can be improved. Here, the alkyl group, alkoxyl group, alkenyl group, and alkynyl group may be linear or branched, and preferably have 1 to 8 carbon atoms, and 2-8. Is more preferable, and it is further more preferable that it is 2-6. When the number of carbon atoms is 8 or less, since the substituent is large, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (3) from being deteriorated. Moreover, since the solubility to the solvent of the polymer or oligomer represented by the general formula (3) is deteriorated when the number of carbon atoms is too small, it is preferably 2 or more. When R ³ and R ⁴ are both substituted, the other carbon number is 4 or more, or the substituted R ¹ , R ^2, R ⁵ , R ⁶ , R ⁷ and / or R ⁸ carbons When the number is large, even if the number of carbon atoms is 1, it shows solubility in a solvent. The aryl group preferably has 6 to 10 carbon atoms. When the number of carbon atoms is 10 or less, it is possible to prevent the FET characteristics of the polymer or oligomer represented by the general formula (3) from being deteriorated because the substituent is large. R ³ and R ⁴ are more preferably a linear alkyl group or a linear alkoxyl group, preferably having 1 to 8 carbon atoms, more preferably 2 to 8 carbon atoms, More preferably, it is 2-6. In the reaction formula (3), a is preferably from 3 to 18, and more preferably from 8 to 12.

  In the reaction formula (3), X represents a halogen atom, and examples thereof include chlorine, fluorine, bromine and iodine. Among these, X is more preferably bromine or iodine. In the reaction formula (3), B represents a relatively active trialkylstannyl group. Among these, the trialkylstannyl group preferably has an alkyl group having 1 to 18 carbon atoms, more preferably 2 to 6 carbon atoms, and tri (n-butyl) for ease of reagent availability. Particularly preferred is a stannyl group or a trimethylstannyl group.

  The double-ended trialkylstannylthiophene or double-ended trialkylstannyl oligothiophene is, for example, obtained by reacting double-ended halogenated thiophene or double-ended halogenated oligothiophene with 2 equivalents of an alkyllithium reagent to give a double-ended lithiated product. Can be obtained by reacting with trialkylchlorostannane.

  The polymer or oligomer can be synthesized by reacting a bis (halogenated thienyl) silane compound with a trialkylstannylthiophene at both ends or a trialkylstannyl oligothiophene at both ends in the presence of a catalyst. Here, since both ends trialkylstannyl (oligothiophene) has a relatively high reactivity, it is desirable to generate it in the system immediately before the reaction with the bis (halogenated thienyl) silane compound. It may be added to the system after purification.

  For example, when trialkylstannyl (oligothiophene) at both ends is generated in the system immediately before the reaction with a bis (halogenated thienyl) silane compound, trialkylstannyl (oligothiophene) at both ends is degassed and dried. It is obtained by the above method in a reaction vessel under an inert gas atmosphere. The obtained both-end trialkylstannyl (oligothiophene) is reacted with 1 equivalent of a bis (halogenated thienyl) silane compound by heating and stirring in the presence of a catalyst without purification. The reaction temperature is preferably 20 ° C. to 150 ° C., and generally the reflux temperature of the solvent used can be used. The reaction time is, for example, about 0.1 to 200 hours.

  After completion of the reaction, the reaction mixture is hydrolyzed by adding distilled water to remove components insoluble in the solvent, the aqueous layer and the oil layer are separated with a separatory funnel, and the aqueous layer is extracted with a solution such as chloroform, Add to oil layer. The obtained polymer solution or oligomer can be obtained by drying and concentrating the obtained chloroform solution and then fractionally precipitating the produced polymer.

  Examples of the solvent used in the above reaction include hydrocarbons such as hexane, pentane, benzene, and toluene; diethyl ether, dipropyl ether, tetrahydrofuran (THF), and the like. Among these, diethyl ether and THF can be used more suitably. Moreover, the said solvent may be used independently, and 2 or more types may be mixed and used for a solvent. The amount of the solvent may be 100 to 100,000 parts by weight per 100 parts by weight in total of trialkylstannyl (oligo) thiophene and bis (halogenated thienyl) silane compound at both ends.

  Moreover, as said catalyst, a palladium catalyst can be used suitably, for example. Of these, dichlorobis (triphenylphosphine) palladium and tetrakis (triphenylphosphine) palladium can be particularly preferably used. Of course, the catalyst is not limited to the palladium catalyst, and any other catalyst can be suitably used.

(III) Electronic Device The electronic device according to the present invention is an electronic device having a semiconductor layer and two or more electrodes, wherein the semiconductor layer contains the organic semiconductor material of the present invention. Examples of such electronic devices include resistors, diodes, amplifying elements such as transistors, transistors, inverters, switching elements such as CMOS, sensors, and the like, devices combining these elements, and integrated devices. Since the organic semiconductor material according to the present invention has both high carrier mobility and on / off ratio, among these, it can be suitably used for a switching element and can be suitably used for a field effect transistor.

  The field effect transistor according to the present invention will be described below. A field effect transistor includes a source electrode, a drain electrode, a channel disposed between the source electrode and the drain electrode, and a gate electrode that is in direct or indirect contact with the channel, and is applied to the gate electrode. The current flowing between the source electrode and the drain electrode is controlled by changing the voltage. In the field effect transistor according to the present invention, the semiconductor layer constituting the channel includes the organic semiconductor material according to the present invention.

  According to the above configuration, the field effect transistor according to the present invention may have advantages by using an organic semiconductor material such as flexibility, compatibility with plastic, reduction of manufacturing cost, compatibility with a large screen device. It becomes possible.

  A field effect transistor according to the present invention includes a source electrode, a drain electrode, a channel disposed between the source electrode and the drain electrode, and a gate electrode that is in direct or indirect contact with the channel. I just need it. Specific examples of the structure include a structure as shown in FIG. 1 (a) or (b). However, the field effect transistor according to the present invention is not limited to the structure having such a structure. It may have a structure other than the structure shown in FIG. In the figure, 1 is a semiconductor layer, 2 is an insulator layer, 3 and 4 are a source electrode and a drain electrode, 5 is a gate electrode, and 6 is a substrate. In addition, arrangement | positioning of each layer and an electrode can be suitably selected according to the use of an electronic device.

The material for the gate electrode, source electrode, and drain electrode may be any material that has conductivity, such as platinum, gold, silver, aluminum, chromium, nickel, cobalt, copper, titanium, magnesium, calcium, sodium, and the like. Metals, alloys containing these metals, conductive oxides such as SnO ₂ , InO ₂ , indium tin oxide (ITO), semiconductors such as silicon, germanium, and gallium arsenide; polyaniline, polypyrrole, polyacetylene, polydiacetylene, Examples thereof include conductive polymer compounds such as polythiophene; carbon materials such as carbon black, fullerene, and graphite. In addition, the conductive polymer compound or the semiconductor may be doped. Examples of the dopant include Lewis acids such as PF ₆ , AsF ₅ and FeCl ₃ ; acids such as hydrochloric acid, sulfuric acid and sulfonic acid; halogen atoms such as iodine and bromine; metal atoms such as sodium and potassium. .

  The electrode can be produced by vapor deposition, sputtering, sol-gel method, coating method, printing method, or the like. Examples of the patterning method include a photolithography method, a printing method such as inkjet printing and letterpress printing, and a combination of these.

  The thickness of the electrode is not particularly limited as long as it is appropriately selected according to the type, structure, etc. of the field effect transistor to be produced. For example, when a field effect transistor having a structure as shown in FIG. 1 is manufactured, the thickness of the electrode is generally preferably 0.01 μm or more and 10 μm or less, and preferably 0.02 μm or more and 0.1 μm or less. More preferred. When it is 0.01 μm or more, it can function as an electrode, and when it is 0.1 μm or less, smoothness can be maintained. However, the preferred electrode thickness is affected by various factors and is not limited to this.

  As the material for the insulator layer, various materials having insulating properties can be used. Examples of such materials include polystyrene, polyvinylphenol, polyimide, polyamide, polymethyl methacrylate, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, phenol resin, and the like; Polymers; oxides such as silicon dioxide, aluminum oxide, titanium oxide, tin oxide and tantalum oxide; nitrides such as silicon nitride and aluminum nitride; ferroelectric oxides such as strontium titanate and barium titanate; or these Examples thereof include polymers in which dielectric particles are dispersed.

  The method for forming the insulator layer may be appropriately selected depending on the material to be used, and examples thereof include vapor deposition, sputtering, CVD, coating, and printing.

The film thickness of the insulator layer is not particularly limited as long as it does not have a pinhole, and may be appropriately selected according to the manufacturing process, the type of material, the structure of the device, and the like. Usually, the thickness can be from about 10 nm, and a thickness of 0.1 to 1 μm is often used. However, the film thickness of the insulator is not limited to this.

  The film thickness of the semiconductor layer may be appropriately selected according to the structure and size of the device, and is not particularly limited. Usually, you can make a pinhole-free from about 10nm. If it is thin, the amount of semiconductor consumption can be reduced. Usually, it is often 200 to 1000 nm, but the thickness of the semiconductor layer is not limited to this.

  The channel length, which is the distance between the source electrode and the drain electrode, may be selected as appropriate according to the size and purpose of the device to be created, and is not particularly limited.

  The semiconductor layer can be formed by, for example, vapor deposition, sputtering, CVD, coating, printing, or the like. Among these, the semiconductor layer is preferably formed by dissolving the organic semiconductor material according to the present invention in a solvent and applying or printing the solution. This eliminates the need for complicated processes under vacuum, such as vapor deposition and CVD, thereby reducing the manufacturing cost of the field effect transistor. Furthermore, the process using coating or printing is suitable for manufacturing a large area device. In addition, as the coating method, for example, spin coating, solution casting, dip coating, or the like can be used. Moreover, as said printing method, screen printing, inkjet printing, etc. can be used, for example. Examples of the solvent for dissolving the organic semiconductor material include chloroform, THF, toluene, chlorobenzene, 1,1,2,2-tetrachloroethylene, 1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane. , Dioxane and the like can be suitably used.

Further, the semiconductor layer may be formed as necessary, for example, Lewis acids such as PF ₆ , AsF ₅ and FeCl ₃ ; acids such as hydrochloric acid, sulfuric acid and sulfonic acid; halogen atoms such as iodine and bromine; metals such as sodium and potassium The conductivity may be adjusted by doping atoms or the like. The doping method is not particularly limited, and a conventionally known method can be used. Doping may be performed after the semiconductor layer is formed, or may be performed simultaneously with the formation of the semiconductor layer. Examples of the doping method include, but are not limited to, gas phase doping, liquid phase doping, solid phase doping, and the like. In addition, when doping is performed simultaneously with the formation of the semiconductor layer, for example, a method of co-evaporating a semiconductor material and a dopant, a method of applying or printing a solution in which the semiconductor material and the dopant are dissolved, and the like can be used.

  Examples of the material of the substrate include glass, ceramics, paper, plastic plate, plastic film, a conductive substrate such as a metal or an alloy formed with an insulating layer, or a combination thereof. In the field effect transistor according to the present invention, since an organic semiconductor material is used, it is not necessary to use a material that can withstand high temperatures as a substrate, and a plastic material such as a plastic plate or a plastic film can be suitably used. Therefore, it is possible to provide a lightweight and flexible electronic device. Examples of such plastic materials include polycarbonate, polyethylene terephthalate, polyphenylene sulfide, polyimide, and the like.

  In addition, the field effect transistor according to the present invention may have a layer other than the layers described above. Examples of such other layers include a protective layer for preventing the influence of outside air.

  The manufacturing method of the field effect transistor according to the present invention is not particularly limited, and each layer may be formed by the above-described method using the materials described above according to the structure. Moreover, the manufacturing method of the field effect transistor concerning this invention may include the process of doping a semiconductor layer as needed, and the process of forming another layer.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example.

[Example 1: Synthesis of organic semiconductor material T10]
<Synthesis of Monomer (4)>
Monomer (4)

Was synthesized by the following method.

  Put 1.58 g (2.5 mmol) of dibutylbis (5′-bromo-2,2′-bithiophen-5-yl) silane and 50 mL of diethyl ether into a 100 mL 2-neck flask purged with nitrogen, and cool to −78 ° C. did. Here, 3.71 mL (5 mmol) of a butyllithium / hexane solution was added dropwise over 1 hour. After slowly returning to room temperature with stirring, the mixture was cooled again to −78 ° C., and 2 mL (5.125 mmol) of tributyltin chloride in 10 mL of diethyl ether was added dropwise over 30 minutes. The resulting mixture was stirred for 12 hours and then hydrolyzed, and the organic layer was separated and washed with water. After drying over anhydrous magnesium sulfate, the solvent was distilled off. The residue was purified by a silica gel column to obtain 2.5 g (yield 95%) of monomer (4) as a brown liquid.

The mass spectrum and NMR data of the obtained monomer (4) are shown below.
TOF-MS m / z 1048.31 (M ⁺ ).
¹ H NMR (δ in CDCl ₃ ) 0.88-0.94 (m, 24H, CH ₃ ), 1.09-1.13 (m, 16H, CH ₂ ), 1.27-1.39 (m, 16H, CH ₂ ), 1.53-1.66 (m , 16H, CH ₂ ), 7.05 (d, 2H, J = 2.7 Hz, thiophene ring protons), 7.20 (d, 2H, J = 3.4 Hz, thiophene ring protons), 7.25 (d, 2H, J = 3.4 Hz, thiophene ring protons), 7.31 (d, 2H, J = 2.7 Hz, thiophene ring protons).
²⁹ Si NMR (δ in CDCl ₃ ) −13.2.

<Synthesis of Monomer (5)>
Monomer (5)

Was synthesized by reactions similar to those in the literature (Naoto Sumi, Hidetaka Nakanishi, Shinpei Ueno, Kazuo Takimiya, Yoshio Aso, and Tetsuo Otsubo, Bull. Chem. Soc. Jpn., 74, 979-988 (2001)).

  Grignard reagent prepared in THF from 2-bromo-3-butylthiophene and an equimolar amount of magnesium was mixed with half an equivalent of 5,5'-dibromo-2,2'-bithiophene and 2 mol% of dichloro (diphenylphosphino). Propane) was reacted under reflux heating in the presence of nickel. The obtained reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment, whereby the corresponding dibutyl quarterthiophene was obtained. Dibutyl quarterthiophene was reacted with 2 equivalents of N-bromosuccinimide in chloroform. The reaction mixture was hydrolyzed and the organic layer was dried and concentrated, and then purified by silica gel column treatment to obtain the corresponding dibromodibutylquaterthiophene. The obtained dibromodibutylquaterthiophene was reacted under reflux heating in the presence of 2 equivalents of 2-thienylmagnesium bromide and 2 mol% of dichloro (diphenylphosphinopropane) nickel. The obtained reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment. As a result, the corresponding dibutylsexithiophene was obtained. The obtained dibutylsecthiophene was reacted with 2 equivalents of N-bromosuccinimide in chloroform. The reaction mixture was hydrolyzed, and the organic layer was dried and concentrated, and then purified by silica gel column treatment to obtain the desired monomer (5).

The obtained monomer (5) was an orange solid, and melting | fusing point was 142-144 degreeC. The data of mass spectrum, NMR and elemental analysis are shown below.
TOF-MS m / z 764.92 (M ⁺ ).
¹ H NMR (δ in CDCl ₃ ); 0.95 (t, 6H, J = 7.6 Hz, CH ₃ ), 1.42 (sext, 4H, J = 7.6 Hz, CH ₂ ), 1.65 (qnt, 4H, J = 7.6 Hz , CH ₂ ), 2.76 (m, 4H, CH ₂ ), 6.89 (d, 2H, J = 4.5 Hz, thiophene ring protons), 6.94 (s, 2H, thiophene ring protons), 6.96 (d, 2H, J = 4.5 Hz, thiophene ring protons), 7.03 (d, 2H, J = 4.5 Hz, thiophene ring protons), 7.19 (d, 2H, J = 2.7 Hz, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ); 13.95, 22.64, 22.18, 32.61, (butyl carbons), 111.00, 123.68, 124.02, 126.56, 126.88, 129.76, 130.69, 133.00 134.80, 136.86, 138.62, 140.57 (thiophene ring carbons) .
Calcd _{(C 32 H 28 Br 2 S} 6): C, 50.26; H, 3.69. Measurements: C, 50.45; H, 3.72.

<Synthesis of T10>
T10 (6)

Was synthesized by the following method.

In a 25 mL two-neck flask purged with nitrogen, 0.49 g (0.64 mmol) of monomer (4), 6.00 mg (0.032 mmol) of CuI, 37 mg (0.032 mmol) of Pd (PPh ₃ ) ₄ , and 5 mL of THF were added. The mixture was cooled to 0 ° C., and 0.673 g (0.64 mmol) of monomer (5) was added dropwise. The mixture was stirred at 80 ° C. for 3 days, the solvent was distilled off, and the resulting residue was reprecipitated from chloroform-ethanol to obtain 0.22 g (32% yield) of T10 as a deep red solid. The melting point was 60-64 ° C. The average molecular weight determined as a result of gel permeation chromatography (GPC) analysis was, in terms of polystyrene, weight average molecular weight Mw = 3800 and dispersion Mw / Mn = 1.18. The degree of polymerization determined from this was 3.5.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.89-0.98 (m, 12H, CH ₃ ), 1.40-1.45 (m, 8H, CH ₂ ), 1.61-1.69 (m, 8H, CH ₂ ), 2.74-2.77 (m , 8H, CH ₂ ), 6.89 (d, 2H, thiophene ring protons, J = 3.6 Hz), 6.93 (s, 2H, thiophene ring protons), 6.96 (d, 2H, J = 3.6 Hz, thiophene ring protons), 7.00-7.23 (m, 12H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.69, 13.93, 14.35, 22.67, 25.83, 26.49, 29.17, 32.61 (butyl carbons), 123.66, 123.97, 124.01, 124.31, 124.59, 124.73, 125.00, 126.41, 126.56, 126.69, 126.88 , 127.82, 130.69, 134.78, 135.97, 136.12, 136.82, 136.89, 140.52, (thiophene ring carbons). One carbon signal seems to overlap.

[Example 2: Synthesis of organic semiconductor material T12]
<Synthesis of Monomer (7)>
Monomer (7)

Was synthesized by reactions similar to those in the literature (Naoto Sumi, Hidetaka Nakanishi, Shinpei Ueno, Kazuo Takimiya, Yoshio Aso, and Tetsuo Otsubo, Bull. Chem. Soc. Jpn., 74, 979-988 (2001)).

  Grignard reagent prepared in THF from 2-bromo-3-butylthiophene and an equimolar amount of magnesium was mixed with half equivalent of 5,5 "-dibromo-2,2" -bithiophene and 2 mol% dichloro (diphenylphosphino). Propane) was reacted under reflux heating in the presence of nickel. The obtained reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment, whereby the corresponding dibutyl quarterthiophene was obtained. Dibutylquaterthiophene was monolithiated by reacting 1 equivalent of butyllithium in THF. To this, a small excess of copper chloride was added at -10 ° C. The reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment, whereby the corresponding tetrabutyloctathiophene was obtained. The obtained tetrabutyloctathiophene was reacted with 2 equivalents of N-bromosuccinimide in chloroform. The reaction mixture was hydrolyzed, and the organic layer was dried and concentrated, and then purified by silica gel column treatment to obtain the desired monomer (7).

The obtained monomer (7) was a deep red solid. The data of mass spectrum, NMR and elemental analysis are shown below.
TOF-MS m / z 1041.77 (M ⁺ ).
_{^{1 H NMR (δ in CDCl 3}} ) 0.89-1.00 (m, 12H, CH 3), 1.34-1.46 (m, 8H, CH 2), 1.58-1.66 (m, 8H, CH 2), 2.61-2.78 (m , 8H, CH ₂ ), 6.89 (s, 2H, thiophene ring protons), 6.96 (d, 2H, J = 3.7 Hz, thiophene ring protons), 7.00-7.07 (m, 6H, thiophene ring protons), 7.12 (d , 2H, J = 3.7 Hz, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.91, 22.50, 22.65, 28.92, 29.22, 32.66 (butyl carbons), 110.72, 116.29, 123.92, 124.13, 126.35, 126.64, 126.98, 131.74, 132.69, 134.94, 137.32, 140.45 (thiophene ring carbons). The signals of 2 butyl group carbon atoms and 4 ring carbon atoms appear to overlap.
Calcd _{(C 48 H 48 Br 2 S} 8): C, 55.37; H, 4.65. Measurements: C, 55.51; H, 4.61.

<Synthesis of T12>
T12 (8)

Was synthesized in the same manner as in <Synthesis of T10> in Example 1 except that the monomer (7) was used instead of the monomer (5). T12 was obtained as a deep red solid (yield 40%). The melting point was 78-82 ° C. The average molecular weight determined as a result of gel permeation chromatography (GPC) analysis was, in terms of polystyrene, weight average molecular weight Mw = 8600 and dispersion Mw / Mn = 1.29. The degree of polymerization determined from this was 5.5.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.91-0.98 (m, 18H, CH ₃ ), 1.41-1.46 (m, 12H, CH ₂ ), 1.61-1.68 (m, 12H, CH ₂ ), 2.75-2.77 (m _{, 12H, CH 2); 7.00-7.22} (m, 24H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.70, 13.90, 14.05, 22.67, 25.87, 26.54, 29.23, 32.62 (butyl carbons), 123.75, 123.98, 124.30, 124.35, 124.38, 124.50, 124.72, 124.96, 125.00, 126.36, 126.66 , 128.60, 128.76, 126.47, 132.21, 132.35, 132.44, 134.87, 135.05, 136.93, 140.54 (thiophene ring carbons). The signals of 3 carbon atoms appear to overlap.

[Example 3: Synthesis of organic semiconductor material T14]
<Synthesis of Monomer (9)>
Monomer (9)

Was synthesized by reactions similar to those in the literature (Naoto Sumi, Hidetaka Nakanishi, Shinpei Ueno, Kazuo Takimiya, Yoshio Aso, and Tetsuo Otsubo, Bull. Chem. Soc. Jpn., 74, 979-988 (2001)).

  Grignard reagent prepared in THF from 2-bromo-3-butylthiophene and an equimolar amount of magnesium under reflux heating in the presence of half equivalent of dibromoterthiophene and 2 mol% dichloro (diphenylphosphinopropane) nickel. Reacted. The obtained reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment. As a result, the corresponding dibutyl quinchithiophene was obtained. Dibutylquinkithiophene was monolithiated by reacting 1 equivalent of butyllithium in THF. To this, a small excess of copper chloride was added at -10 ° C. The reaction mixture was hydrolyzed, and the organic layer was dried and concentrated, and then purified by silica gel column treatment to obtain the corresponding tetrabutyldecathiophene. The obtained tetrabutyldecathiophene was reacted with 2 equivalents of N-bromosuccinimide in chloroform. The reaction mixture was hydrolyzed, the organic layer was dried and concentrated, and then purified by silica gel column treatment to obtain the desired monomer (9).

The obtained monomer (9) was a deep red solid, and melting | fusing point was 145-147 degreeC. The data of mass spectrum, NMR and elemental analysis are shown below.
TOF-MS m / z 1206.72 (M ⁺ ).
¹ H NMR (δ in CDCl ₃ ) 0.90-0.97 (m, 12H, CH ₃ ), 1.35-1.44 (m, 8H, CH ₂ ), 1.54-1.66 (m, 8H, CH ₂ ), 2.68-2.75 (m , 8H, CH ₂ ), 6.88 (s, 2H, thiophene ring protons), 6.94 (d, 2H, J = 3.6 Hz, thiophene ring protons), 6.98-7.11 (m, 12H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.86, 13.99, 22.57, 22.67, 28.93, 29.25, 32.65 (butyl carbons), 110.62, 123.91, 124.07, 124.29, 124.46, 126.37, 126.66, 126.93, 131.75, 132.77, 133.93, 134.86 , 135.18, 135.78, 136.11, 136.55, 137.19, 140.42, 140.55 (thiophene ring carbons). The signals for one butyl group carbon atom and one ring carbon atom appear to overlap.
Calcd _{(C 56 H 52 Br 2 S} 10): C, 55.80; H, 4.35. Measurement: C, 55.79; H, 4.35.

<Synthesis of T14>
T14 (10)

Was synthesized in the same manner as in <Synthesis of T10> in Example 1 except that the monomer (9) was used instead of the monomer (5). T14 was obtained as a deep red solid (yield 76%). The melting point was 78-81 ° C. The average molecular weight determined as a result of gel permeation chromatography (GPC) analysis was, in terms of polystyrene, weight average molecular weight Mw = 9200, and dispersion Mw / Mn = 1.38. The degree of polymerization determined from this was 7.0.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.89-0.99 (m, 18H, CH ₃ ), 1.27-1.47 (m, 12H, CH ₂ ), 1.58-1.71 (m, 12H, CH ₂ ), 2.69-2.79 (m , 12H, CH ₂ ), 6.93-7.23 (m, 24H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.69, 13.98, 14.36, 22.67, 25.84, 26.50, 29.25, 32.59 (butyl carbons), 123.90, 124.05, 124.47, 124.59, 124.71, 125.02, 126.34, 126,41, 126.65, 126 , 97, 127.82, 128.44, 128.57, 129.49, 132.72, 134.86, 135.01, 135.97, 136.06, 136.12, 136.63, 136.71, 136.82, 136.89, 140.56, 143.09, 143.50 (thiophene ring carbons). The signals of 3 carbon atoms appear to overlap.

[Example 4: Synthesis of organic semiconductor material T5]
<Synthesis of Monomer (11)>
Monomer (11) (Bis (5-bromothien-2-yl) ethoxy-n-propylsilane)

Was synthesized by the following method.

  To a 200 mL three-necked flask, 2.0 g (82.6 mmol) of magnesium was added, and 50 mL of THF was added. A very small amount (about 0.03 g) of dibromoethylene was added to activate magnesium, and then 20.0 g (82.6 mmol) of 2,5-dibromothiophene was slowly dropped from the dropping funnel. After dropwise addition of the entire amount, the mixture was refluxed overnight to obtain a monogriniard body.

  To this, 8.5 g (41.3 mmol) of n-propyltriethoxysilane was added and stirred at room temperature for 1 hour and then refluxed overnight. Distilled water was added to the reaction solution to hydrolyze the remaining Grignard reagent, followed by extraction with ether. The ether solution was dehydrated with anhydrous magnesium sulfate and then concentrated with an evaporator. The obtained crude product was distilled under reduced pressure to isolate the target monomer (11) as a colorless transparent liquid with a yield of 31%. The boiling point was 110 ° C. to 115 ° C./133.224 Pa.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.98 (t, H), 1.04-1.10 (m, H), 1.19 (t, H), 1.21-1.56 (m, H), 3.77 (q, 2H, —OCH ₂ -), 7.13 (4H, thienylene).
¹³ C NMR (δ in CDCl ₃ ) 16.4, 17.9, 18.1, 18.2, 59.8, 119.0, 131.4, 136.7, 137.2.
²⁹ Si NMR ((δ in CDCl ₃ ) -14.72.

<Synthesis of T5>
T5 (12)

Was synthesized according to J. Ohshita, A. Takata, A. Kunai, M. Kakimoto, Y. Harima, Y. Kunugi, K. Yamashita, J. Organomet. Chem., 611, 537-542 (2000).

  First, 812 g (2.00 mmol) of 5,5 ″ -dibromo-2,2 ′: 5′2 ″ -terthiophene was placed in a 50 mL Schlenk tube under an argon gas atmosphere, and 20 mL of THF was added. After cooling to −80 ° C. and dropwise addition of n-butyllithium hexane solution (4.3 mmol), the mixture was returned to room temperature and stirred for 30 minutes.

Next, the reaction solution was cooled to −10 ° C., 1.40 g (4.30 mmol) of tributyltin chloride (n-Bu ₃ SnCl) was added dropwise, and after slowly returning to room temperature, the mixture was stirred overnight. To this solution, 0.880 g (2.00 mmol) of monomer (11) and 0.100 g of tetrakistriphenylphosphine palladium (Pd (PPh ₃ ) ₄ ) (about 4.3 mol% with respect to the monomer) were added and stirred well. And refluxed for 40 hours.

  After returning to room temperature, it was hydrolyzed by adding distilled water, the aqueous layer and the oil layer were separated with a separatory funnel, and the aqueous layer was extracted with chloroform and added to the oil layer. The obtained chloroform solution was dried over magnesium sulfate and concentrated with an evaporator, and then the obtained crude product was reprecipitated with ethanol / chloroform and further purified by reprecipitation with n-hexane / chloroform.

  As a result, orange powdery T5 (0.631 g, yield 60%) was obtained. The average molecular weight determined as a result of gel permeation chromatography (GPC) analysis was, in terms of polystyrene, weight average molecular weight Mw = 10000 and dispersion Mw / Mn = 1.7.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.87-1.26 (m, 12H), 3.85 (q, —OCH ₂ —), 7.07-7.33 (m, 10H, thienylene).
¹³ C NMR (δ in CDCl ₃ ) 16.6, 18.0, 18.3, 18.5, 59.8, 124.4, 125.0, 133.6, 136.0, 136.3, 137.6, 143.7.
²⁹ Si NMR ((δ in CDCl ₃ ) -13.46.

[Example 5: Synthesis of organic semiconductor material T7]
<Synthesis of Monomer (13)>
Monomer (13)

Was synthesized according to J. Ohshita, A. Takata, A. Kunai, M. Kakimoto, Y. Harima, Y. Kunugi, K. Yamashita, J. Organomet. Chem., 611, (2000), 537-542.

  In a 100 mL two-necked flask, 0.50 g (1.23 mmol) of dibromoterthiophene and 50 mL of diethyl ether were added and stirred, and cooled to -78 ° C. To this solution, 2.46 mmol of butyllithium in hexane was added over 1 hour. After slowly returning to room temperature, it was cooled again to −78 ° C., and 0.70 mL (2.46 mmol) of 10 mL diethyl ether solution of tributyltin chloride was added over 30 minutes. After stirring for 4 hours at room temperature, the organic layer was taken out by hydrolysis. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off. When the residue was purified by silica gel column chromatography, 0.96 g (94% yield) of monomer (13) was obtained.

The mass spectrum and NMR data of the obtained monomer (13) are shown below.
¹ H NMR (δ in CDCl ₃ ) 0.88-0.92 (m, 18H, CH ₃ ), 1.09-1.13 (m, 12H, CH ₂ ), 1.30-1.39 (m, 12H, CH ₂ ), 1.53-1.64 (m _{, 12H, CH 2), 7.05-7.06} (br, 4H, thiophene ring protons), 7.27 (d, 2H, J = 3.4 Hz, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 10.88, 13.64, 27.24, 28.93, (butyl carbons), 124.00, 124.68, 127.82, 136.12, 136.72, 142.63 (thiophene ring carbons).

<Synthesis of Monomer (14)>
Monomer (14)

Was synthesized according to X. Jiang, Y. Harima, K. Yamashita, A. Naka, K.-K. Lee, M. Ishikawa, J. Mater. Chem., 13, (2003), 785-794.

  A 100 mL two-necked flask was charged with 5.0 g (15 mmol) of dibromobithiophene and 50 mL of diethyl ether and cooled to -78 ° C. To this solution, 9.64 mmol of butyllithium in hexane was added over 4 hours. After slowly returning to room temperature, the mixture was cooled again to −78 ° C., and 1.64 g (7.71 mmol) of dibutyldichlorosilane in 10 mL of diethyl ether was added. After stirring for 12 hours at room temperature, the organic layer was taken out by hydrolysis. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off. When the residue was purified by silica gel column chromatography, 4.35 g (45% yield) of monomer (14) was obtained.

The mass spectrum and NMR data of the obtained monomer (14) are shown below.
TOF-MS m / z 629.14 (M ⁺ ).
¹ H NMR (δ in CDCl ₃ ) 0.87-0.91 (m, 6H, CH ₃ ), 1.06-1.10 (m, 4H, CH ₂ ), 1.33-1.44 (m, 8H, CH ₂ ), 6.80-6.96 (m , 4H, thiophene ring protons), 7.17-7.25 (m, 4H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.68, 14.25, 25.79, 26.47, (butyl carbons), 111.23, 124.09, 125.23, 130.64, 135.08, 136.81, 138.64, 142.41 (thiophene ring carbons).

<Synthesis of T7>
T7 (15)

Was synthesized by the following method.

In a 25 mL two-necked flask, 0.300 g (0.362 mmol) of monomer (13), 3.40 mg (0.0181 mmol) of CuI, 20.1 mg (0.0181 mmol) of Pd (PPh ₃ ) ₄ and 5 mL of toluene And cooled in an ice bath. Thereto was added 0.229 g (0.362 mmol) of monomer (14), and the mixture was stirred at 100 ° C. for one day. The solvent was distilled off, and the residue was reprecipitated from chloroform-ethanol to obtain 0.10 g (yield 40%) of polymer T7 as an orange solid.

  The melting point was 82-86 ° C. The average molecular weight determined as a result of gel permeation chromatography (GPC) analysis was, in terms of polystyrene, weight average molecular weight Mw = 5900 and dispersion Mw / Mn = 1.22.

The NMR data is shown below.
¹ H NMR (δ in CDCl ₃ ) 0.89-0.92 (m, 6H, CH ₃ ), 1.09-1.12 (m, 4H, CH ₂ ), 1.38-1.46 (m, 8H, CH ₂ ); 6.94-7.25 (m , 14H, thiophene ring protons).
¹³ C NMR (δ in CDCl ₃ ) 13.69, 14.35, 25.84, 26.49, (butyl carbons), 124.08, 124.32, 124.41, 124.74, 125.00, 125.24, 127.82, 130.64, 134.91, 136.10, 136.20, 136.81, 136.92, 143.07 ( thiophene ring carbons).

[Example 6: Fabrication of field effect transistor and measurement of FET characteristics]
A field effect transistor having the structure shown in FIG. 2 was produced by the following method. The structure shown in FIG. 2 is classified into a bottom contact type structure, similar to the structure shown in FIG. As shown in FIG. 2, the field effect transistor fabricated in this example uses a doped silicon substrate 8 that also serves as a substrate and a gate electrode. In FIG. 2, 7 is a contact (gate contact).

A 230 nm SiO ₂ film (insulator layer 2) was coated on a doped silicon wafer (substrate (gate electrode) 8) (self-made) by thermal oxidation. The back surface (the surface opposite to the insulator layer 2 side of the substrate 8) is etched with a hydrofluoric acid aqueous solution, the SiO ₂ film coated on the back surface is removed, and an exposed substrate is obtained by an electron beam method. Gold was vapor-deposited on 8 to produce a gate contact 7. Further, on the insulator layer 2 formed on the substrate 8, gold was evaporated by an electron beam method to form the source electrode 3 and the drain electrode 4. The channel length was 10 μm and the channel width was 2 cm. Further thereon, the obtained polymers T10, T12, T14 and T5 were each spin-coated from a chloroform solution to form a semiconductor layer 1 to produce a field effect transistor of the present invention.

The properties of the field effect transistor thus obtained were measured using R6246 (manufactured by Advantest) under vacuum at room temperature. The FET characteristics of the device were measured under room temperature vacuum. In the measurement, a voltage of 0 to −100 V is applied between the source and the drain of the manufactured field effect transistor, and the voltage applied between the source and the gate is changed in the range of 0 V to −100 V, so that the voltage between the source and the drain is changed. This was done by measuring the current flowing against the applied voltage (Vd). From the obtained measurement data, the following equation id = {Wμ (Vg−Vt) ² Ci} / 2L
Was used to determine the carrier mobility (μ) (Y. Kunugi, K. Takimiya, K. Yamashita, Y. Aso, T. Otsubo, Chem. Lett., 958 (2002)). Here, id is a current flowing with respect to a voltage Vd applied between the source and drain, Vg is a voltage applied between the source and gate, Vt is a threshold voltage, and Ci is a unit area of the insulator layer. , W represents the channel width, and L represents the channel length. The on / off ratio is the maximum and minimum between the source and drain when a voltage of −100 V is applied between the source and drain and the voltage applied between the source and gate is changed in the range of 0 V to −100 V. It was calculated | required as ratio of the electric current which flows into.

  The table below shows the carrier mobility (μ) and the on / off ratio of field effect transistors manufactured using T10, T12, T14, T7, and T5 as organic semiconductor materials, respectively.

  As shown in Table 1, it was found that all of T10, T12, T14, T7, and T5 exhibited FET characteristics. It was also found that the carrier mobility was 1 order of magnitude higher when the thiophene chain in each repeating unit was composed of 12, 14 thiophenes than when it was composed of 5, 7, 10 thiophenes. Furthermore, as the thiophene of the thiophene chain in the repeating unit increased to 7, 10, and 12, the on / off ratio increased 10 times. Since only T5 contains an alkoxyl group (ethoxy group) in the substituent bonded to the silicon atom, the substituent bonded to the silicon atom is an alkoxyl group (ethoxy group) than when the substituent is an alkyl group (butyl group). It is considered that the FET characteristics were improved, and that the on / off ratio of T5 was larger than that of T7. On the other hand, even when the thiophene in the thiophene chain in the repeating unit increased from 12 to 14, neither the on-off ratio nor the carrier mobility was improved. From these results, in an organic semiconductor containing a thiophene chain and a silicon atom in the main chain, the FET characteristics are improved until the length of the thiophene chain reaches a certain length, but the thiophene chain is longer than a certain length. It has been found that the degree of improvement in FET characteristics decreases with increasing length.

  As described above, the organic semiconductor material according to the present invention can be used for electronic devices such as field effect transistors. Therefore, it is possible to effectively use the advantages of organic semiconductor materials such as provision of lightweight and flexible electronic devices, suppression of electronic device manufacturing costs by not requiring a vacuum process, and facilitation of large screen device manufacturing. . Therefore, the present invention can be used not only in the chemical industry that manufactures organic semiconductor materials, but also in the semiconductor industry that manufactures various electronic devices using the organic semiconductor materials, and also manufactures various products incorporating electronic devices. It can also be used in the electronic equipment manufacturing industry, and is considered to be very useful.

1 illustrates an embodiment of the present invention, and (a) and (b) are schematic diagrams illustrating a configuration example of a field effect transistor according to the present invention. It is a schematic diagram which shows the structure of the field effect transistor produced in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor layer 2 Insulator layer 3 Source electrode 4 Drain electrode 5 Gate electrode 6 Substrate 7 Gate contact 8 Substrate (gate electrode)

Claims (9)

General formula (1) or (2)

(In (1) and (2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group, and R ³ , R ⁴ , R ⁵ and R ⁶ independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxyl group, or an aryl group, n represents an integer of 2 or more, and X represents an integer of 5 or more.)
An organic semiconductor material comprising a polymer or oligomer having a structure represented by: ^2. The organic semiconductor material according to claim 1, wherein the polymer or oligomer has a carrier mobility (μ) of 1 × 10 ⁻⁶ cm ² / Vs or more and an on / off ratio of 10 or more. .   Said X is 10-14, The organic-semiconductor material of Claim 1 or 2 characterized by the above-mentioned. In said general formula (1) and (2), R < ³ >, R < ⁴ >, R < ⁵ > and R < ⁶ > are respectively independently a C1-C8 alkyl group, a C1-C8 alkoxyl group, carbon number 1 The organic semiconductor material according to claim 1, wherein the organic semiconductor material is an alkenyl group having 8 to 8 carbon atoms, an alkynyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 10 carbon atoms.   In said general formula (1) and (2), n is 2-1000, The organic-semiconductor material of any one of Claims 1-4.   An electronic device having a semiconductor layer and two or more electrodes, wherein the semiconductor layer includes the organic semiconductor material according to any one of claims 1 to 5.   The electronic device according to claim 6, wherein the electronic device is a switching element.   The electronic device according to claim 7, wherein the electronic device is a field effect transistor. A source electrode, a drain electrode, a channel disposed between the source electrode and the drain electrode, and a gate electrode directly or indirectly in contact with the channel, and changing a voltage applied to the gate electrode In the field effect transistor that controls the current flowing between the source electrode and the drain electrode by
A semiconductor layer constituting the channel includes the organic semiconductor material according to claim 1.

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