JP2005206750A - Organic semiconductive material, organic transistor, field-effect transistor, switching element, and five-membered heterocyclic compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductive material which has a high carrier mobility and an excellent shelf stability, and to provide an organic transistor, a field-effect transistor and a switching transistor each using this organic semiconductive material. <P>SOLUTION: The organic semiconductive material contains a compound having a partial structure expressed by general formula (1), (2) or (3), (wherein A<SP>1</SP>through A<SP>4</SP>are each a carbon atom, a nitrogen atom, a sulfur atom or an oxygen atom; A<SP>5</SP>through A<SP>16</SP>are each a carbon atom or a nitrogen atom), and the partial structure expressed by general formula (1), (2) or (3) may have a substituent, but a five-membered ring comprising A<SP>1</SP>and A<SP>2</SP>and a five-membered ring comprising A<SP>3</SP>and A<SP>4</SP>have the same structure with the relation of a point symmetry. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic semiconductor material, an organic transistor and a field effect transistor using the material, and the organic transistor or a switching element using the field effect transistor.

  With the widespread use of information terminals, there is an increasing need for flat panel displays as computer displays. In addition, with the progress of computerization, information that has been provided on paper media in the past has become more and more electronically provided. As a mobile display medium that is thin, light, and easy to carry, electronic paper or There is a growing need for digital paper.

  In general, in a flat display device, a display medium is formed using an element utilizing liquid crystal, organic EL, electrophoresis, or the like. In such display media, a technique using an active drive element (TFT element) as an image drive element has become mainstream in order to ensure uniformity of screen brightness, screen rewrite speed, and the like. For example, in a normal computer display, these TFT elements are formed on a glass substrate, and liquid crystal, organic EL elements, etc. are sealed.

  Here, semiconductors such as a-Si (amorphous silicon) and p-Si (polysilicon) can be mainly used for the TFT element, and these Si semiconductors (and metal films as necessary) are formed into a multilayer structure. The TFT element is manufactured by sequentially forming the drain and gate electrodes on the substrate. The manufacture of such a TFT element usually requires sputtering or other vacuum manufacturing processes.

  However, in the manufacture of such a TFT element, the vacuum system manufacturing process including the vacuum chamber must be repeated many times to form each layer, and the apparatus cost and running cost have become enormous. For example, in a TFT element, it is usually necessary to repeat processes such as vacuum deposition, dope, photolithography, development, etc. many times to form each layer, and the element is formed on a substrate through tens of steps. ing. A plurality of types of semiconductor layers, such as p-type and n-type, are also stacked on the semiconductor portion that is the key to the switching operation. In such a conventional manufacturing method using a Si semiconductor, it is not easy to change the equipment, for example, a design change of a manufacturing apparatus such as a vacuum chamber is required in response to the need for a large display screen.

  In addition, since the formation of such a conventional TFT element using a Si material includes a process at a high temperature, the substrate material is restricted to be a material that can withstand the process temperature. Therefore, in practice, glass must be used, and when the above-described thin display such as electronic paper or digital paper is configured using such a conventionally known TFT element, the display is heavy and flexible. Products that may break due to chipping or dropping impact. These characteristics resulting from the formation of TFT elements on a glass substrate are undesirable in satisfying the need for an easy-to-carry-type thin display accompanying the progress of computerization.

  On the other hand, in recent years, organic semiconductor materials have been energetically studied as organic compounds having high charge transport properties. These compounds have been reported in many papers such as organic laser oscillation elements as discussed in Non-Patent Document 1, etc., and Non-Patent Document 2, for example, in addition to charge transport materials for organic EL elements. Application to organic thin film transistors is expected. If these organic semiconductor devices can be realized, there is a possibility of obtaining a semiconductor that can be made into a solution by simplifying the manufacturing process by vacuum or low-pressure deposition at a relatively low temperature and further improving the molecular structure appropriately. It is conceivable that the organic semiconductor solution is made into an ink and manufactured by a printing method including an ink jet method. Manufacturing by these low-temperature processes has been considered impossible for conventional Si-based semiconductor materials, but there is a possibility for devices using organic semiconductors, so the above-mentioned restrictions on substrate heat resistance are relaxed. For example, a TFT element may be formed on the transparent resin substrate. If a TFT element is formed on a transparent resin substrate and the display material can be driven by the TFT element, the display is lighter and more flexible than conventional ones, and will not crack even if dropped (or very difficult to break) It could be a display.

  However, organic semiconductors for realizing such TFT elements have been studied so far as acenes such as pentacene and tetracene (for example, see Patent Document 1), phthalocyanines including lead phthalocyanine, perylene and its tetra. Low molecular weight compounds such as carboxylic acid derivatives (for example, see Patent Document 2), aromatic oligomers typically represented by thiophene hexamers called α-thienyl or sexithiophene (for example, see Patent Document 3), naphthalene, Compounds in which a 5-membered heteroaromatic ring is condensed symmetrically on anthracene (for example, see Patent Document 4), mono, oligo and polydithienopyridines (for example, see Patent Document 5), polythiophene, polythienylene vinylene, poly -Conjugated polymers such as p-phenylene vinylene Etc. limited number of compounds (e.g., see Non-Patent Documents 1 to 3.) Have only in the development of the semiconductor composition using the novel charge-transporting material showing high carrier mobility has been awaited.

In addition, in Japanese Patent Application Laid-Open No. 2003-292588, US Patent Application Publication Nos. 2003/136958, 2003/160230, and 2003/164495, “integrated circuit logic element for microelectronics and polymer TFT However, many of the semiconductor polythiophenes are oxidatively doped with ambient oxygen, which increases the conductivity, and thus increases the electrical conductivity. As a result, devices made from these materials have higher off-currents, and therefore lower current on / off ratios, so many of these materials are used in material processing and device manufacturing. To eliminate or minimize oxidative doping by eliminating environmental oxygen in between This precautionary measure raises the cost of manufacturing, and the appeal of certain polymer TFTs as an economical alternative to amorphous silicon technology, especially for large area devices, is diminished. These and other disadvantages are avoided or minimized in embodiments of the present invention, so an electronic device with strong resistance to oxygen and a relatively high current on / off ratio is desired. However, the level of improvement is not satisfactory, and further improvement is desired.
JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP-A-11-195790 JP 2003-155289 A “Science” 289, 599 (2000) “Nature” 403, 521 (2000) Advanced Material, 2002, No. 2, page 99

  An object of the present invention is to provide an organic semiconductor material having high carrier mobility and excellent storage stability, and an organic transistor, a field effect transistor and a switching element using the organic semiconductor material.

  The above object of the present invention is achieved by the following.

(Claim 1)
An organic semiconductor material comprising a compound having a partial structure represented by the following general formula (1), (2) or (3).

(Wherein, A ¹ to A ⁴ are carbon atoms, nitrogen atom, a sulfur atom or an oxygen atom, A ⁵ to A ¹⁶ represents a carbon atom or a nitrogen atom, the general formula (1), (2) or (3 ) May have a substituent, provided that the 5-membered ring formed by A ¹ and A ² and the 5-membered ring formed by A ³ and A ⁴ are in a point-symmetric relationship. It is a certain same structure.)
(Claim 2)
The organic semiconductor material according to claim 1, wherein the compound having a partial structure represented by the general formula (1), (2) or (3) is a polymer.

(Claim 3)
An organic transistor using the organic semiconductor material according to claim 1 for an active layer.

(Claim 4)
An organic charge transporting material and a gate electrode that is in direct contact with or indirectly in contact with the organic charge transporting material, and by applying a charge between the gate electrode and the organic charge transporting material, A field effect transistor for controlling the current of the organic charge transport material, wherein the organic charge transporting material is the organic semiconductor material according to claim 1.

(Claim 5)
A switching element comprising the organic transistor according to claim 3 or the field effect transistor according to claim 4.

(Claim 6)
A compound having a partial structure represented by the general formula (1), (2) or (3) according to claim 1.

  According to the present invention, an organic semiconductor material having high carrier mobility and excellent storability, an organic transistor, a field effect transistor and a switching element using the organic semiconductor material can be provided. Further, the organic transistor of the present invention was able to increase the ratio between the maximum current value and the minimum current value when the gate voltage was changed, that is, the ON / OFF ratio.

  Hereinafter, the present invention will be described in detail.

  In the partial structure represented by the general formula (1), (2) or (3), the dotted line represents a single bond or a double bond.

  The partial structure represented by the general formula (1), (2) or (3) may have a substituent. Examples of preferable substituents include an alkyl group (for example, a methyl group, an ethyl group, a propyl group). , Isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, Vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), heteroaryl group (eg, furyl group, thienyl group, pyridyl group, etc.) Pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, ben Imidazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy) Group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.) Alkylthio groups (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio groups (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio Group (for example, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group ( For example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylamino) Sulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, Acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (For example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethyl group) Carbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octyl Carbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, Cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethyl) Ureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, -Pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group) Group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl) Group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino) Group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg. , Fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.) These substituents may be further substituted with the above substituents, or a plurality thereof may be bonded to each other to form a ring.

  Preferred examples of the substituent include an alkyl group, a cycloalkyl group, an alkoxy group, an alkylthio group, an alkoxyalkyl group, an amino group substituted with an alkyl group, an alkylcarbamoyl group, and an alkoxycarbonyl group, and particularly preferably a carbon number of 5 or more. The alkyl group is 20 or less, or a linear alkoxy group having the same number of atoms, more preferably a linear alkyl group having 5 to 10 carbon atoms.

  Hereinafter, although the specific compound of the compound which has a partial structure shown by General formula (1), (2) or (3) is illustrated below, it is not limited to these.

  Hereinafter, although synthesis examples are shown for some of the specific compound examples, others can be synthesized in the same manner.

  Synthesis Example 1 (Synthesis of Compound (13))

(13) Synthesis of c In a nitrogen atmosphere, 200 ml of a compound (13) a (compound described in J. Org. Chem., 59, 11, 1994, 3077-3081), 4.4 g (10 mmol) in a three-necked flask Tetrahydrofuran 60ml was added and it cooled to -70 degrees C or less. Next, 7.3 ml (11 mmol) of t-butyllithium (1.5 mol / L pentane solution) was added dropwise and stirred at the same temperature for 2 hours, and then 4.1 g (22 mmol) of Compound (13) b (Aldrich Reagent) was added. 10 ml of tetrahydrofuran solution was quickly added, and the mixture was further stirred at the same temperature for 2 hours, and further stirred at room temperature for 12 hours. After completion of stirring, the reaction solution was washed with saturated brine, dried over magnesium sulfate, and then concentrated under reduced pressure using a rotary evaporator. The residue was recrystallized with ethanol to obtain 3.0 g of white crystals. It was confirmed by 1H-NMR and mass spectrum that there was no contradiction with the target product.

Synthesis of (13) Compound (13) c, 3.0 g (6.8 mmol) and Compound (13) d (Chem. Europ. J., 8, 13, 2002, compounds described in 3027-3046), 4.8 g ( 6.8 mmol) in toluene (30 ml), and under nitrogen, tetrakis (triphenylphosphine) palladium 0.15 g (0.13 mmol), Aliqart 336 (Aldrich reagent) 1.0 g in toluene solution 10 ml, and 2 mol / L Aqueous sodium carbonate (10 ml) was added. The mixture was stirred vigorously and heated to reflux for 48 hours. The viscous reaction liquid was poured into methanol (500 ml) to obtain a precipitate. The precipitate was filtered, purified by Soxhlet extraction with toluene, reprecipitated from methanol, and dried in a vacuum oven at 60 ° C. overnight. The molecular weight of the obtained precipitate as measured by GPC was 32000, and the spectral characteristics were consistent with the structure of the target product.

  Synthesis Example 2 (Synthesis of Compound (21))

Synthesis of (21) b Compound (21) a (compound described in Chem. Ber., 119, 10, 1986, 3198-3203), 1.9 g (10 mmol) and 50 ml of chloroform were added to a 100 ml, three-necked flask. The reaction system was cooled to 5 ° C. or less, and 1.8 g (10 mmol) of N-bromosuccinimide was added little by little. After completion of the addition, the mixture was stirred at room temperature for 1 hour, washed with saturated brine, dried over magnesium sulfate, and then concentrated under reduced pressure using a rotary evaporator. The residue was purified by column chromatography to obtain 2.2 g of a white solid. It was confirmed by 1H-NMR and mass spectrum that there was no contradiction with the target product.

(21) Synthesis of c 100 ml, 0.10 g (4.1 mmol) of magnesium was added to a three-necked flask, and the inside of the system was purged with nitrogen. Next, 30 ml of tetrahydrofuran was added, and 10 ml of a tetrahydrofuran solution of compound (21) b, 1.1 g (4.1 mmol) was slowly added dropwise with stirring. The resulting mixture was stirred at room temperature for 2 hours and then refluxed for 30 minutes to obtain reaction solution A.

  To a 200 ml three-necked flask, 10 mg of [1,3-bis (diphenylphosphino) propane] nickel (II), compound (21) b, 1.1 g (4.1 mmol) was added, and the system was purged with nitrogen. Next, 40 ml of tetrahydrofuran was added, and the reaction solution A was slowly added dropwise at room temperature with stirring. After completion of the addition, the reaction solution was stirred at room temperature for 12 hours. After completion of the reaction, the reaction solution was added little by little to 200 ml of water. After completion of the addition, the organic layer was washed with saturated brine, dried over magnesium sulfate, and then concentrated under reduced pressure using a rotary evaporator. The residue was purified by column chromatography to obtain 1.4 g of a yellow solid. It was confirmed by 1H-NMR and mass spectrum that there was no contradiction with the target product.

(21) Synthesis of d 100 ml, Compound (21) c, 1.4 g (3.7 mmol) and 50 ml of chloroform were added to a three-necked flask, the reaction system was cooled to 5 ° C. or lower, and N-bromosuccinimide 1. 4 g (7.8 mmol) was added in small portions. After completion of the addition, the mixture was stirred at room temperature for 1 hour, washed with saturated brine, dried over magnesium sulfate, and then concentrated under reduced pressure using a rotary evaporator. The residue was purified by column chromatography to obtain 1.5 g of a yellow solid. It was confirmed by 1H-NMR and mass spectrum that there was no contradiction with the target product.

Synthesis of (21) 200 ml, 0.1 g of tetrakis (triphenylphosphine) palladium (0) and compound (21) e (J. Chem. Soc. Perkin Trans. 1, 8, 2000, 1211-1216 in a three-necked flask The described compound) and 2.5 g (6.0 mmol) were added, and the inside of the system was purged with nitrogen. Further, 40 ml of tetrahydrofuran was added, and with stirring, 10 ml of a tetrahydrofuran solution of compound (21) d, 1.5 g (2.8 mmol) and 10 ml of a 2 mol / L aqueous sodium carbonate solution were added and heated to reflux for 10 hours. After completion of the reaction, diatomaceous earth filtration was performed at room temperature, and the filtrate was washed with saturated brine, dried over magnesium sulfate, and then concentrated under reduced pressure using a rotary evaporator. The residue was purified by column chromatography to obtain 2.1 g of yellow crystals. It was confirmed by 1H-NMR and mass spectrum that there was no contradiction with the target product.

  The organic semiconductor material of the present invention can be provided in an active layer of an organic thin film transistor element to provide a transistor device that can be driven satisfactorily.

  The organic thin film transistor has a source electrode and a drain electrode connected by an organic semiconductor channel (active layer) on a support, a top gate type having a gate electrode on the support, and a gate electrode on the support. First, it is roughly classified into a bottom gate type having a gate electrode and having a source electrode and a drain electrode connected by an organic semiconductor channel through a gate insulating layer.

  In order to install the compound of the present invention in the active layer of the organic thin film transistor device, it can be installed on the substrate by vacuum deposition, but a solution prepared by dissolving in an appropriate solvent and adding additives as necessary is cast coated. It is preferably installed on the substrate by spin coating, printing, ink jet method, ablation method or the like. In this case, the solvent for dissolving the organic semiconductor of the present invention is not particularly limited as long as the organic semiconductor can be dissolved to prepare a solution having an appropriate concentration. Specifically, diethyl ether, diisopropyl ether, etc. Chain ether solvents, cyclic ether solvents such as tetrahydrofuran and dioxane, ketone solvents such as acetone and methyl ethyl ketone, alkyl halide solvents such as chloroform and 1,2-dichloroethane, toluene, o-dichlorobenzene, nitrobenzene, Aromatic solvents such as m-cresol, N-methylpyrrolidone, carbon disulfide and the like can be mentioned.

  In the present invention, the material for forming the source electrode, the drain electrode, and the gate 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, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, lithium / aluminum mixture, etc., especially platinum, gold, silver, copper, aluminum, indium, ITO And carbon are preferred. 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. Among them, those having low electrical resistance at the contact surface with the semiconductor layer are preferable.

  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.

  Various insulating films can be used as the gate insulating layer, and an inorganic oxide film having a high relative dielectric constant is particularly preferable. Inorganic oxides include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Examples thereof include barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, and yttrium trioxide. Of these, silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide are preferable. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used.

  Examples of the method for forming the film include a vacuum process, a molecular beam epitaxial growth method, an ion cluster beam method, a low energy ion beam method, an ion plating method, a CVD method, a sputtering method, an atmospheric pressure plasma method, and a spray process. Wet processes such as coating methods, spin coating methods, blade coating methods, dip coating methods, casting methods, roll coating methods, bar coating methods, die coating methods, and other wet processes such as printing and ink jet patterning methods, etc. Can be used depending on the material.

  The wet process is a method of applying and drying a liquid in which fine particles of inorganic oxide are dispersed in an arbitrary organic solvent or water using a dispersion aid such as a surfactant as required, or an oxide precursor, for example, A so-called sol-gel method in which a solution of an alkoxide body is applied and dried is used. Among these, the atmospheric pressure plasma method and the sol-gel method are preferable.

  The method for forming an insulating film by plasma film formation under atmospheric pressure is a process in which a reactive gas is discharged under atmospheric pressure or a pressure near atmospheric pressure to excite reactive gas to form a thin film on a substrate. The method is described in JP-A-11-61406, JP-A-11-133205, JP-A-2000-121804, JP-A-2000-147209, and JP-A-2000-185362 (hereinafter referred to as atmospheric pressure plasma method). Also called). Accordingly, a highly functional thin film can be formed with high productivity.

  In addition, as the organic compound film, polyimide, polyamide, polyester, polyacrylate, photo radical polymerization type, photo cation polymerization type photo curable resin, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolac resin, Also, cyanoethyl pullulan or the like can be used. As the method for forming the organic compound film, the wet process is preferable. An inorganic oxide film and an organic oxide film can be laminated and used together. The thickness of these insulating films is generally 50 nm to 3 μm, preferably 100 nm to 1 μm.

  Moreover, a support body is comprised with glass or a flexible resin-made sheet | seat, for example, a plastic film can be used as a sheet | seat. 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.

  Below, the field effect transistor using the organic thin film which consists of an organic-semiconductor material of this invention is demonstrated.

  FIG. 1 shows a schematic configuration example of a field effect transistor using the organic semiconductor material of the present invention. In FIG. 2A, a source electrode 2 and a drain electrode 3 are formed on a support 6 by a metal foil or the like, an organic semiconductor layer 1 made of the organic semiconductor material of the present invention is formed between the two electrodes, and a substrate is formed thereon. An insulating layer 5 is formed, and a gate electrode 4 is further formed thereon to form a field effect transistor. FIG. 2B shows the organic semiconductor layer 1 formed between the electrodes in FIG. 1A so as to cover the entire surface of the electrode and the support using a coating method or the like. (C) shows that the organic semiconductor layer 1 is first formed on the support 6 by using a coating method or the like, and then the source electrode 2, the drain electrode 3, the insulating layer 5, and the gate electrode 4 are formed.

  In FIG. 4D, after forming the gate electrode 4 on the support 6 with a metal foil or the like, the insulating layer 5 is formed, and the source electrode 2 and the drain electrode 3 are formed on the metal foil or the like on the insulating layer 5. An organic semiconductor layer 1 made of the organic semiconductor material of the present invention is formed between the electrodes. In addition, the configuration as shown in FIGS.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, the embodiment of this invention is not limited to these.

Example 1
A silicon oxide having a resistivity of 0.01 Ω · cm as a gate electrode was formed with a thermal oxide film having a thickness of 2000 mm to form a gate insulating layer, and then surface treatment with octadecyltrichlorosilane was performed. A chloroform solution of comparative compound (1) (poly (3-hexylthiophene) (regioregular, Aldrich, average molecular weight 89000, PHT)) was applied using an applicator and dried naturally to give a cast film (thickness 50 nm) And was heat-treated at 50 ° C. for 30 minutes in a nitrogen atmosphere. Furthermore, gold was deposited on the surface of this film using a mask to form source and drain electrodes. An organic thin film transistor element 1 having a width of 100 μm, a thickness of 200 nm, a channel width W = 3 mm, and a channel length L = 20 μm was prepared.

  The organic thin film transistor element 2 is the same as the organic thin film transistor element 1 except that the comparative compound (1) is replaced with the comparative compound (2) (US Patent Application Publication No. 2003/164495, Exemplified Compound (3)). Was made.

  Further, organic thin film transistor elements 3 to 6 were produced in the same manner as the organic thin film transistor element 1 except that the comparative compound (1) was replaced with the exemplary compounds of the present invention shown in Table 1.

  The organic thin film transistor elements 2 to 6 fabricated as described above showed good operating characteristics of a p-channel enhancement type FET. Further, with respect to the organic thin film transistor elements 2 to 6, the carrier mobility is obtained from the saturation region of the IV characteristic, and further the ON / OFF ratio (the drain bias is −50V and the drain current value when the gate bias is −50V and 0V). Ratio). The obtained element was left in the atmosphere for one month, and the carrier mobility and the ON / OFF ratio were obtained again. The results are shown in Table 1.

  From the results of Table 1, it was found that the organic thin film transistor element of the present invention has good characteristics as a transistor and further suppressed deterioration over time.

Example 2
The organic thin film transistor element was the same as the organic thin film transistor element 1 except that the comparative compound (1) in Example 1 was replaced with the comparative compound (3) (pentacene, a commercially available reagent manufactured by Aldrich). 11 was produced.

  Furthermore, organic thin-film transistor elements 12-15 were produced by the same method as the organic thin-film transistor element 1, except that the comparative compound (1) was replaced with the exemplary compounds of the present invention shown in Table 2.

  The organic thin film transistor elements 1 and 12 to 15 manufactured as described above exhibited good operating characteristics of p-channel enhancement type FETs. Further, for the organic thin film transistor elements 11 to 15, from the saturation region of the IV characteristic, the carrier mobility and the ON / OFF ratio (the drain bias value ratio when the drain bias is −50 V and the gate bias is −50 V and 0 V) Asked. The obtained element was left in the atmosphere for one month, and the carrier mobility and the ON / OFF ratio were obtained again. The results are shown in Table 2.

  From the results of Table 2, it was found that the organic thin film transistor element of the present invention has good characteristics as a transistor and further suppressed deterioration with time. Moreover, although the result of the organic transistor element 11 using the comparative compound (3) clearly shows that it is difficult to obtain a pentacene thin film functioning as an active layer by forming a thin film by coating, the organic thin film transistor element of the present invention is As a result, it was found that the thin film formation by coating showed good characteristics as a transistor.

It is a figure which shows the schematic structural example of the field effect transistor using organic-semiconductor material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic-semiconductor layer 2 Source electrode 3 Drain electrode 4 Gate electrode 5 Insulating layer 6 Support body

Claims (6)

An organic semiconductor material comprising a compound having a partial structure represented by the following general formula (1), (2) or (3).

(Wherein, A ¹ to A ⁴ are carbon atoms, nitrogen atom, a sulfur atom or an oxygen atom, A ⁵ to A ¹⁶ represents a carbon atom or a nitrogen atom, the general formula (1), (2) or (3 ) May have a substituent, provided that the 5-membered ring formed by A ¹ and A ² and the 5-membered ring formed by A ³ and A ⁴ are in a point-symmetric relationship. It is a certain same structure.) The organic semiconductor material according to claim 1, wherein the compound having a partial structure represented by the general formula (1), (2) or (3) is a polymer. An organic transistor using the organic semiconductor material according to claim 1 for an active layer. An organic charge transporting material and a gate electrode that is in direct contact with or indirectly in contact with the organic charge transporting material, and by applying a charge between the gate electrode and the organic charge transporting material, A field effect transistor for controlling the current of the organic charge transport material, wherein the organic charge transporting material is the organic semiconductor material according to claim 1. A switching element comprising the organic transistor according to claim 3 or the field effect transistor according to claim 4. A compound having a partial structure represented by the general formula (1), (2) or (3) according to claim 1.

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