JP2007088016A - Organic semiconductor material, organic semiconductor film, organic semiconductor device, organic thin-film transistor, and organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an organic semiconductor film to be formed by coating an organic semiconductor material having improved solvent solubility, to provide an organic semiconductor device and an organic thin-film transistor, having high carrier mobility, by using the obtained organic semiconductor film, and to provide an organic EL element having the device or the transistor. <P>SOLUTION: The organic semiconductor material contains a compound expressed by an expression (1). In the expression (1), A indicates a fused aromatic hydrocarbon ring or fused aromatic heterocycle, where at least two rings are condensed, and Ar<SB>1</SB>-Ar<SB>4</SB>indicate an aromatic hydrocarbon ring or aromatic heterocycle each; R<SB>1</SB>-R<SB>8</SB>indicate a hydrogen atom, a halogen atom, or substituent each, or may be connected together to form a ring; n indicates 0 or 1; a and b indicate an integer of 0-3 each; and a and b satisfy 1≤(a+b). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic semiconductor material, an organic semiconductor film, an organic semiconductor device, an organic thin film transistor, and an organic electroluminescence element.

  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 in paper media has been increasingly digitized. As a mobile display medium that is thin, light, and portable, electronic paper or digital paper can be used. The need for is increasing.

  In general, in a flat panel display device, a display medium is formed using elements utilizing liquid crystal, organic EL (organic electroluminescence), 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. Yes. As for the semiconductor portion that is the key to the switching operation, a plurality of types of semiconductor layers such as p-type and n-type are stacked. In 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. In addition to the charge transport material for organic EL elements, these compounds can be used for organic laser oscillation elements (see, for example, Non-Patent Document 1) and organic thin-film transistor elements (organic TFT elements) (for example, see Non-Patent Document 2). The application of 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 such as acenes such as pentacene and tetracene (for example, see Patent Document 1), phthalocyanines containing lead phthalocyanine, perylene and its Low molecular weight compounds such as tetracarboxylic acid derivatives (see, for example, Patent Document 2), aromatic oligomers typically represented by thiophene hexamers called α-thienyl or sexualthiophene (see, for example, Patent Document 3), and naphthalene. , A compound in which a 5-membered aromatic heterocycle is condensed symmetrically to anthracene (for example, see Patent Document 4), mono-, oligo- and polydithienopyridine (for example, see Patent Document 5), polythiophene, polythienylene. Conjugated polymers such as vinylene and poly-p-phenylene vinylene 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, most of the semiconductor polythiophenes are oxidatively doped with ambient oxygen, which increases the electrical conductivity because of their increased electrical durability. As a result, the off-state current of devices made from these materials is large, and therefore the current on / off ratio is small.

  Therefore, many of these materials have the problem that strict precautions must be taken to eliminate or minimize oxidative doping by eliminating environmental oxygen during material processing and device fabrication.

  Such precautionary measures increase manufacturing costs, which can reduce the attractiveness of certain polymer TFTs as an economical alternative to amorphous silicon technology, especially for large area devices. These and other disadvantages are avoided or minimized in embodiments of the present invention. Therefore, an electronic device having a strong resistance to oxygen and having a relatively high current ONN / OFF ratio is desired, "and various solutions have been proposed (for example, patents). References 6, 7 and 8) are not satisfactory in the level of improvement, and further improvements are desired.

  On the other hand, conventionally known pentacene, which is well known as an organic semiconductor material, has high crystallinity due to its strong intermolecular cohesive force, and thus exhibits high carrier mobility and excellent semiconductor device characteristics. It has been reported.

  As a background showing such excellent semiconductor properties, it is known that pentacene molecules are regularly arranged. However, since pentacene is insoluble or hardly soluble in an organic solvent, there is a problem that it is difficult to form a film by coating.

  In order to solve this problem, an example in which a pentacene dispersion is heated at a high temperature and a film is formed by coating (for example, see Non-Patent Document 4) has been reported. There are problems such as the fact that the work is complicated and the use of a halogen-based solvent, which has a large environmental load and is concerned about safety to the human body.

  Further, compounds in which a substituent is introduced into pentacene have been proposed (see, for example, Non-Patent Document 6), and some of these compounds are soluble in a relatively highly volatile solvent such as toluene. The carrier mobility of the film remains at an insufficient value, and there is still a problem in achieving both solubility and carrier mobility. Moreover, there is no disclosure regarding the on / off ratio.

  Recently, a very high mobility has been reported by a single crystal of rubrene, which is a highly soluble acene (see, for example, Non-Patent Document 5). Such a single crystal structure is not taken and sufficient mobility is not obtained.

  Furthermore, in addition to solvent solubility, these acene compounds such as rubrene and pentacene have a major problem that they are easily oxidized by air and easily converted into oxidants and dimers such as endoperoxides. is there. Such oxidation and dimerization are known to greatly degrade the performance as a field effect transistor, and there are still problems to be solved regarding the storage stability in solution and the stability of the coating film. It is left.

  In response to this problem, as an example of an acene compound having high solvent solubility and relatively stable against oxidation, some compounds in which the 6th and 13th positions of pentacene are substituted with silylethynyl groups have improved coating film stability. It is reported that it is good (see, for example, Non-Patent Documents 7 to 10).

However, these reports only describe the qualitative properties in the text that the stability against oxidation has been improved, and the stability to the extent that it can withstand practical use has not yet been obtained.
JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP-A-11-195790 JP 2003-155289 A JP 2003-261655 A JP 2003-264327 A JP 2003-268083 A “Science” 289, 599 (2000) “Nature” 403, 521 (2000) Advanced Material, 2002, No. 2, page 99 Proc. ICSM-2004 Science, 2004, 303, 5664, 1644-1646. International Publication No. 03/028125 Pamphlet Org. Lett. , Vol. 4 (2002), 15 pages J. et al. Am. Chem. Soc. , Vol. 127 (2005), p4986 J. et al. Am. Chem. Soc. , Vol. 123 (2001), p9486 US Pat. No. 6690029 Specification

  An object of the present invention is to provide an organic semiconductor material having improved solvent solubility, and an organic semiconductor film can be formed by applying the organic semiconductor material. Using the obtained organic semiconductor film, carrier mobility can be formed. An organic semiconductor device, an organic thin film transistor, and an organic EL element including the device or the transistor are provided.

  The above object of the present invention has been achieved by the following constitutions 1-12.

(1)
An organic semiconductor material comprising a compound represented by the following general formula (1):

[Wherein, A represents a condensed aromatic hydrocarbon ring or a condensed aromatic heterocyclic ring in which at least two rings are condensed, and Ar _{1 to} Ar ₄ each represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring. R _{1 to} R ₈ each represent a hydrogen atom, a halogen atom or a substituent, and may be connected to each other to form a ring. n represents 0 or 1. a and b each represent an integer of 0 to 3, and a and b satisfy the following relational expression (1). ]
Relational expression (1)
1 ≦ (a + b)
(2)
Said a and b satisfy | fill the following relational expression (2), The organic-semiconductor material as described in said (1) characterized by the above-mentioned.

Relational expression (2)
2 ≦ (a + b)
(3)
The organic semiconductor material as described in (1) or (2) above, wherein the compound represented by the general formula (1) has a weight average molecular weight in the range of 250 to 10,000.

(4)
An organic semiconductor material comprising a compound represented by the following general formula (2):

[In the formula, Ar _{1 to} Ar ₇ each represents an aromatic hydrocarbon ring or an aromatic heterocycle, R _{1 to} R ₁₅ each represents a hydrogen atom, a halogen atom or a substituent, and each ring is linked to each other to form a ring. May be formed. n represents 0 or 1. a and b each represent an integer of 0 to 3, and a and b satisfy the following relational expression (1), c and d each represent an integer of 0 to 5 and c , D satisfies the following relational expression (3). ]
Relational expression (1)
1 ≦ (a + b)
Relational expression (3)
1 ≦ (c + d)
(5)
5. The organic semiconductor material as described in 4 above, wherein a, b, c and d satisfy the following relational expressions (4) and (5).

Relational expression (4)
2 ≦ (a + b)
Relational expression (5)
2 ≦ (c + d)
(6)
The organic semiconductor material as described in (4) or (5) above, wherein the compound represented by the general formula (2) has a weight average molecular weight in the range of 250 to 10,000.

(7)
Said Ar < ₁ > -Ar < ₇ > respectively represents an aromatic hydrocarbon ring, The organic-semiconductor material of any one of said (4)-(6) characterized by the above-mentioned.

(8)
An organic semiconductor film comprising the organic semiconductor material according to any one of (1) to (7).

(9)
An organic semiconductor film formed by dissolving the organic semiconductor material according to any one of (1) to (7) in an organic solvent, and applying and drying the prepared solution. .

(10)
An organic semiconductor device using the organic semiconductor material according to any one of (1) to (7).

(11)
An organic thin film transistor using the organic semiconductor material according to any one of (1) to (7) in a semiconductor layer.

(12)
An organic electroluminescence element comprising the organic semiconductor device according to (10) or the organic thin film transistor according to (11).

  According to the present invention, an organic semiconductor material with improved solvent solubility is provided, and an organic semiconductor film can be formed by applying the organic semiconductor material. Using the obtained organic semiconductor film, carrier mobility is high. It was possible to provide an organic semiconductor device, an organic thin film transistor, and an organic EL device including the device or the transistor.

  In the organic semiconductor material of the present invention, an organic semiconductor film useful for thin film transistor applications can be obtained by using the configuration defined in any one of claims 1 to 5. In addition, it was found that an organic thin film transistor (also referred to as an organic TFT) manufactured using the organic semiconductor film has excellent transistor characteristics such as high carrier mobility and good ON / OFF characteristics. Moreover, it turned out that the organic electroluminescent element provided with organic TFT shows a favorable light emission characteristic.

  Hereinafter, details of each component according to the present invention will be sequentially described.

《Organic semiconductor material》
The organic semiconductor material of the present invention will be described.

  As a conventionally known organic semiconductor material, a compound in which two or more aromatic rings are linearly condensed, such as acenes represented by pentacene, is well known as a high mobility material. However, aromatic rings with a large number of condensed rings have strong intermolecular cohesive force, and therefore have low solvent solubility and are difficult to apply to a process using a solution.

  As a result of various investigations for searching for a compound having good solvent solubility while having the characteristics as a high mobility material which is a characteristic of acenes typified by pentacene, the present inventors have more than two rings. Condensed aromatic rings are directly linked, and each linked aromatic ring has such a twisted structure in the molecule that the π planes of each are displaced from the same plane due to steric hindrance and twisted at an angle. By suppressing the physical addition of oxygen by increasing steric hindrance and improving the stability against oxidation, and by suppressing the intermolecular cohesion between the compounds, the solvent solubility of the compound is greatly improved, In addition, by providing an aromatic ring having a condensed many rings as a partial structure, an organic thin film transistor having high mobility and high stability against oxidation by a coating method (also called a solution process) can be obtained. It has been found that it is possible to provide a formed acceptable organic semiconductor material.

  Here, the aromatic ring in the present invention refers to an aromatic hydrocarbon ring and an aromatic heterocyclic ring unless otherwise specified. The aromatic hydrocarbon ring and aromatic heterocyclic ring will be described in detail later.

<< Compound Represented by Formula (1) >>
The compound represented by the general formula (1) according to the present invention will be described.

  The organic semiconductor material of the present invention is characterized by containing a compound represented by the general formula (1), and is characterized by containing at least the compound represented by the general formula (1) as a main component. It is. Here, the main component means that 50% by mass or more of the total mass of the organic semiconductor material is contained. Of course, the compound represented by the general formula (1) may be contained in the organic semiconductor material of the present invention at a content of 100% by mass.

  In the general formula (1), examples of the condensed aromatic hydrocarbon ring in which at least two rings represented by A are condensed include a naphthalene ring, an azulene ring, a naphthacene ring, an anthracene ring, a tetracene ring, a pentacene ring, and a heptacene ring. , Hexacene ring, phenanthrene ring, pyrene ring, benzopyrene ring, benzoazulene ring, chrysene ring, benzochrysene ring, acenaphthene ring, acenaphthylene ring, triphenylene ring, coronene ring, benzocoronene ring, hexabenzocoronene ring, fluorene ring, benzofluorene ring, Examples include a fluoranthene ring, a perylene ring, a naphthoperylene ring, a pentabenzoperylene ring, a benzoperylene ring, a pentaphen ring, a picene ring, a pyranthrene ring, a coronene ring, a naphthocoronene ring, an ovalene ring, and an anthrathrene ring.

  In the general formula (1), A is preferably a condensed aromatic heterocycle in which at least two rings are condensed, and any one of a nitrogen atom, a sulfur atom, and an oxygen atom is included in the atomic group constituting the ring. , Benzimidazole ring, indole ring, benzimidazole ring, benzothiazole ring, thienothiophene ring, dithienobenzene ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring, acridine ring, benzoquinoline ring , Phenazine ring, phenanthridine ring, phenanthroline ring, carboline ring, cyclazine ring, kindlin ring, tepenidine ring, quinindrine ring, triphenodithiazine ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, dia Zacarbazole (Any one of the carbon atoms constituting the carboline ring is replaced with a nitrogen atom), phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, benzodifuran ring, benzodithiophene ring, naphthodifuran ring Naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, thiophanthrene ring (naphthothiophene ring) and the like.

Any of the above condensed aromatic hydrocarbon ring and condensed aromatic heterocyclic ring may have a substituent represented by each of R _{1 to} R ₈ in the general formula (1) described later.

  In the general formula (1), among the condensed aromatic hydrocarbon rings or condensed aromatic heterocycles represented by A, it is preferable that the A is composed of only a 6-membered ring. The case where it represents a hydrogen ring or a condensed aromatic heterocyclic ring, or the case where A represents a condensed aromatic hydrocarbon ring is preferred.

In the general formula (1), examples of the aromatic hydrocarbon ring represented by Ar _{1 to} Ar ₄ include benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene. Ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene And a ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring. Further, the aromatic hydrocarbon ring may have a substituent represented by each of R _{1 to} R ₈ in the general formula (1) described later.

In the general formula (1), examples of the aromatic heterocycle represented by Ar _{1 to} Ar ₄ include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, Triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring , Quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (showing a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom) Etc. Furthermore, the aromatic heterocyclic ring may have a substituent represented by each of R _{1 to} R ₈ in the general formula (1) described later.

  Here, the aromatic heterocyclic ring according to the present invention may contain a nitrogen atom, a sulfur atom, a phosphorus atom, a selenium atom, a tellurium atom, etc. as a ring constituent atom (also referred to as a constituent element). Those in which either a sulfur atom or an oxygen atom is included in the atomic group constituting the ring are preferable.

In the general formula (1), examples of the substituent represented by R _{1 to} R ₈ include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group, a hexyl group, Octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl) Group, propargyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), aromatic heterocyclic group (eg, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl) Group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carboliyl Group, a diazacarbazolyl group (in which one of carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (for example, a pyrrolidyl group, Imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, Cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group) Etc.), cycloalkyl Thio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyl) Oxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butyl) Aminosulfonyl, hexylaminosulfonyl, cyclohexylaminosulfonyl, octylaminosulfonyl, dodecylaminosulfonyl, phenylaminosulfonyl, naphth Ruaminosulfonyl 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, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, Rohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethyl) Aminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group Group), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octyl) Luureido group, dodecylureido group, phenylureido group naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecyl) Sulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group) Etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group) Group), 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 atoms (for example, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon groups (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, Examples thereof include a nitro group, a hydroxy group, a mercapto group, and a silyl group (for example, a trimethylsilyl group, a triisopropylsilyl group, a triphenylsilyl group, and a phenyldiethylsilyl group).

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  In the general formula (1), a and b satisfy the above relational expression (1), but preferably satisfy the above relational expression (2).

  Among the compounds represented by the above general formula (1), the compound represented by the above general formula (2) is more preferably used.

<< Compound Represented by Formula (2) >>
The compound represented by the general formula (2) according to the present invention will be described.

In the general formula (2), the aromatic hydrocarbon rings each represented by Ar _{1 to} Ar ₇ have the same meaning as the aromatic hydrocarbon rings represented by Ar _{1 to} Ar ₄ in the general formula (1). is there.

In General Formula (2), each of Ar _{1 to} Ar ₇ is the same as the aromatic heterocycle represented by Ar _{1 to} Ar ₄ in General Formula (1).

In the general formula (2), the substituents represented by R _{1 to} R ₁₅ have the same meanings as the substituents represented by R _{1 to} R ₈ in the general formula (1).

(Weight average molecular weight of the compound represented by the general formula (1) or the general formula (2))
The molecular weight of the compound represented by the general formula (1) or the general formula (2) according to the present invention is preferably such that the weight average molecular weight is in the range of 250 to 10,000, more preferably 250 to 5. , 000. Furthermore, the ratio (molecular weight distribution) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) according to the present invention is preferably 2 or less.

  The weight average molecular weight (Mw) and number average molecular weight (Mn) of the organic semiconductor compound of the present invention are measured using GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a column solvent.

  Specifically, 1 ml of THF (using a degassed sample) is added to 1 mg of a measurement sample, and the sample is stirred using a magnetic stirrer at room temperature to be sufficiently dissolved. Next, after processing with a membrane filter having a pore size of 0.45 μm to 0.50 μm, it is injected into the GPC apparatus.

  The measurement conditions of GPC are measured by stabilizing the column at 40 ° C., flowing THF at a flow rate of 1 ml / min, and injecting about 100 μl of a sample having a concentration of 1 mg / ml. As the column, it is preferable to use a combination of commercially available polystyrene gel columns. For example, Shodex GPC KF-801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK, TSKgel G1000H, G2000H, G3000H, G4000H, G5000H, G6000H, G7000H, TSK guard column manufactured by Tosoh Corporation Combinations can be given.

  As the detector, a refractive index detector (RI detector) or a UV detector is preferably used. In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodisperse polystyrene standard particles. About 10 points are preferably used as polystyrene for preparing a calibration curve.

  In the present invention, the molecular weight was measured under the following measurement conditions.

(Measurement condition)
Apparatus: HLC-8020 (manufactured by Tosoh Corporation)
Column: GMHXLx2, G2000HXLx1
Detector: RI and / or UV
Eluent flow rate: 1.0 ml / min Sample concentration: 0.01 g / 20 ml
Sample volume: 100 μl
Calibration curve: prepared with standard polystyrene The compound represented by the general formula (1) or the general formula (2) relating to the organic semiconductor material of the present invention is, for example, J. Org. Am. Chem. Soc. 64, 1253 (1942).

  Hereinafter, although the specific example of a compound represented by General formula (1) or General formula (2) based on this invention is shown, this invention is not limited to these.

<Organic semiconductor film>
The organic semiconductor film according to the present invention will be described.

  The organic semiconductor material of the present invention can be mixed with an appropriate organic solvent (described later) and used as a solution or dispersion.

  When producing an organic semiconductor film using a solution containing the organic semiconductor material of the present invention, any organic solvent may be used, or two or more organic solvents may be mixed and used. Preferably, it contains at least one non-halogen solvent, and more preferably only non-halogen solvent.

<< Solution or dispersion at room temperature >>
The organic semiconductor film of the present invention is preferably produced through a step of forming a film using a solution or a dispersion at room temperature, prepared by mixing the organic semiconductor material of the present invention with the organic solvent shown below. Here, the solution or dispersion at room temperature preferably forms a solution or dispersion when the organic semiconductor material and the organic solvent are mixed under conditions of 10 ° C. to 80 ° C. Although the organic semiconductor material represents a state where the organic semiconductor material is dispersed in the form of particles, a state where the organic semiconductor material is partially dissolved in the dispersion is also included.

  Further, as one embodiment of the dispersion, for example, it dissolves under a temperature condition of 80 ° C. to form a solution, but when returned to room temperature (usually showing a temperature of about 25 ° C.), particles or aggregates of organic semiconductor material And a state in which precipitates are dispersed in an organic solvent.

(Organic solvent)
There is no restriction | limiting in particular as an organic solvent used for preparation of said solution or dispersion liquid, Although a single solvent or a mixed solvent may be sufficient, Preferably, a non-halogen-type solvent is used. Non-halogen solvents used in the present invention include aliphatic solvents such as hexane and octane, alicyclic solvents such as cyclohexane, aromatic solvents such as benzene, toluene and xylene, tetrahydrofuran, dioxane, and ethylene glycol diethyl ether. , Ether solvents such as anisole, benzyl ethyl ether, ethyl phenyl ether, diphenyl ether, and methyl-t-butyl ether, ester solvents such as methyl acetate, ethyl acetate, and ethyl cellosolve, alcohol solvents such as methanol, ethanol, and isopropanol, acetone , Ketone solvents such as methyl ethyl ketone, cyclohexanone, 2-hexanone, 2-heptanone and 3-heptanone, other dimethylformamide, dimethylsulfoxide, diethylformamide, 1,3- Oxolane, and the like.

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

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

<< Organic semiconductor device, organic thin film transistor (also called organic TFT) >>
The organic semiconductor device and organic thin film transistor (also referred to as organic TFT in the present application) of the present invention will be described.

  The organic semiconductor material of the present invention can be used for a semiconductor layer such as an organic semiconductor film, an organic semiconductor device, and an organic thin film transistor (organic TFT), thereby providing an organic semiconductor device and an organic TFT that are driven well.

  An organic TFT (organic thin film transistor) has a source electrode and a drain electrode connected by an organic semiconductor channel as a semiconductor layer on a support, and a top gate type having a gate electrode via a gate insulating layer thereon, A bottom gate type having a gate electrode on a support and having a source electrode and a drain electrode connected by an organic semiconductor channel through a gate insulating layer is roughly classified.

  In order to install the organic semiconductor material of the present invention on the semiconductor layer of the organic TFT, 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. It is preferable to install on the substrate by coating, spin coating, printing, ink jet method, ablation method or the like.

  In this case, the solvent for dissolving the organic semiconductor compound according to the present invention is not particularly limited as long as the organic semiconductor compound can be dissolved to prepare a solution with an appropriate concentration. Chain ether solvents such as diisopropyl ether, 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 And aromatic solvents such as nitrobenzene and m-cresol, N-methylpyrrolidone, carbon disulfide and the like. Of these solvents, a solvent containing a non-halogen solvent is preferable, and a non-halogen solvent is preferable.

  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, magnesi A copper / gold mixture, a magnesium / silver mixture, a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide mixture, a lithium / aluminum mixture, etc., in particular, 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, JP-A-2000-185362 (hereinafter referred to as atmospheric pressure). Also called plasma method). 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 organic thin-film transistor (organic TFT) using the organic thin film formed using the organic-semiconductor compound concerning this invention is demonstrated.

  FIG. 1 is a diagram showing a configuration example of an organic TFT according to 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 thin film transistor material of the present invention is formed between the two electrodes, and on that, 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 thin film transistor material of the present invention is formed between the electrodes. In addition, the configuration as shown in FIGS.

  FIG. 2 is a diagram showing an example of a schematic equivalent circuit diagram of an organic TFT sheet.

  The organic TFT sheet 10 has a large number of organic TFTs 11 arranged in a matrix. 7 is a gate bus line of each TFT 11, and 8 is a source bus line of each TFT 11. An output element 12 is connected to the source electrode of each TFT 11, and the output element 12 is, for example, a liquid crystal or an electrophoretic element, and constitutes a pixel in the display device. The pixel electrode may be used as an input electrode of the photosensor. In the illustrated example, a liquid crystal as an output element is shown by an equivalent circuit composed of a resistor and a capacitor. 13 is a storage capacitor, 14 is a vertical drive circuit, and 15 is a horizontal drive circuit.

  In addition, the organic TFT using the organic semiconductor material of the present invention can be applied to the technology introduced in SID2005, sessions 49-1, 2 and 3.

  Hereinafter, as an example of the technology application, an organic electroluminescence element (organic EL element) including the organic TFT of the present invention will be described.

<< Organic EL element (Organic electroluminescence element) >>
The organic semiconductor device or the organic thin film transistor of the present invention can be provided in an organic electroluminescence element (also referred to as an organic EL element). The organic EL element of the present invention has, for example, an organic EL layer (between an anode and a cathode) The organic compound layer) may be sandwiched between them, and these structures can be prepared using a conventionally known layer structure, a material of an organic EL layer, or the like. For example, the literature etc. of Nature, 395 volumes, 151-154 pages can be referred.

  In light emitting the organic EL element of the present invention (for example, applied to a display device, a lighting device, etc.), the organic semiconductor device of the present invention is obtained from the viewpoint of obtaining high light emission luminance and a long light emission lifetime. Or it is preferable to have the organic thin-film transistor of this invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. Here, structural formulas of comparative organic semiconductor materials (also referred to as organic semiconductor compounds) used in the examples are shown below.

Example 1
<< Preparation of Organic Thin-Film Transistor 1 >>: Comparative Example After forming a 2000 mm thick thermal oxide film on a Si wafer having a specific resistance of 0.01 Ω · cm as a gate electrode to form a gate insulating layer, surface treatment with octadecyltrichlorosilane Went.

  On a Si wafer subjected to such a surface treatment, the comparative compound (1) (pentacene, used by sublimation purification of a commercial reagent manufactured by Aldrich) was used in a nitrogen atmosphere for 0 minutes with respect to toluene bubbled with nitrogen for 30 minutes. , Dissolved at a concentration of 5% by mass, spin-coated under a nitrogen atmosphere (rotation speed: 2500 rpm, 15 seconds), naturally dried to form a cast film, and heat-treated at 50 ° C. for 30 minutes in a nitrogen atmosphere Was given.

  Furthermore, gold was deposited on the surface of this film using a mask to form source and drain electrodes. An organic thin film transistor 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.

<< Preparation of Organic Thin Film Transistor 2 >>: Comparative Example An organic thin film transistor 2 was prepared in the same manner as in the preparation of the organic thin film transistor 1 except that the comparative compound 1 was changed to the comparative compound 2, and the following semiconductor characteristics were evaluated.

  Comparative compound 2 (2,3,9,10-tetrahexylpentacene) is described in Organic Letters, vol. 2 (2000), p85.

<< Preparation of Organic Thin-Film Transistor 3 >>: Comparative Example In the preparation of the organic thin-film transistor 1, the organic compound was prepared in the same manner except that the comparative compound 1 was changed to the comparative compound 3 (rubberene, a commercially available reagent manufactured by Aldrich). A thin film transistor 3 was produced.

<< Preparation of Organic Thin Film Transistor 4 >> Comparative Example An organic thin film transistor 4 was prepared in the same manner as in the preparation of the organic thin film transistor 1 except that the comparative compound 1 was changed to the comparative compound 4.

  Comparative compound 4 was prepared according to J.M. Am. Chem. Soc. , Vol. 123 (2001), p9486, supporting information.

<< Preparation of Organic Thin Film Transistors 5 to 15 >>: Present Invention In the preparation of the organic thin film transistor 1, the organic thin film transistors 5 to 5 were prepared in the same manner except that the organic semiconductor material of the present invention shown in Table 1 was used instead of the comparative compound 1. 15 was produced.

<< Evaluation of carrier mobility and ON / OFF value >>
About the obtained organic thin-film transistors 1-15, the carrier mobility and ON / OFF value of each element were measured immediately after element preparation. In the present invention, the carrier mobility is obtained from the saturation region of the IV characteristic, and the ON / OFF ratio is obtained from the ratio of the drain current values when the drain bias is −50 V and the gate bias is −50 V and 0 V. It was.

  In the same evaluation, each element was placed in an environmental chamber at 40 ° C. and 90% RH for 48 hours, and then the carrier mobility / ON / OFF ratio was measured again.

  The obtained results are shown in Table 1.

From Table 1, compared with the comparative organic thin film transistor, the organic thin film transistors 5 to 15 of the present invention exhibit excellent characteristics in both carrier mobility and ON / OFF ratio immediately after fabrication, and the mobility is also after the durability test. It shows a numerical value of 10 ⁻² or more and an ON / OFF ratio of 10 ⁵ or more, with little deterioration over time and high durability.

Example 2
<< Production of organic EL element >>
The organic EL element was produced by referring to the method described in Nature, Vol. 395, pages 151 to 154, and producing a top emission type organic EL element having a sealing structure as shown in FIG. 3, 101 is a substrate, 102a is an anode, 102b is an organic EL layer (specifically, an electron transport layer, a light emitting layer, a hole transport layer, etc. are included), 102c is a cathode, and an anode 102a The light emitting element 102 is formed by the organic EL layer 102b and the cathode 102c. Reference numeral 103 denotes a sealing film. The organic EL element of the present invention may be either a bottom emission type or a top emission type.

  The organic EL element of the present invention and the organic thin film transistor of the present invention (herein, the organic thin film transistor of the present invention is used as a switching transistor, a driving transistor, etc.) were produced to produce an active matrix light emitting element. For example, as shown in FIG. 4, a mode in which a substrate in which a TFT 602 (or an organic thin film transistor 602 may be formed) is formed on a glass substrate 601 is used as an example. Here, a known TFT manufacturing method can be referred to for the TFT 602 manufacturing method. Of course, the TFT may be a conventionally known top gate TFT or bottom gate TFT.

  The organic EL device produced above showed good light emission characteristics in various light emission forms such as single color, full color, and white.

It is a figure which shows the structural example of the organic TFT which concerns on this invention. It is an example of the schematic equivalent circuit schematic of the organic TFT of this invention. It is a schematic diagram which shows an example of the organic EL element which has a sealing structure. It is a schematic diagram which shows an example of the board | substrate which has TFT used for an organic EL element.

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 7 Gate bus line 8 Source bus line 10 Organic TFT sheet 11 Organic TFT
DESCRIPTION OF SYMBOLS 12 Output element 13 Storage capacitor 14 Vertical drive circuit 15 Horizontal drive circuit 101, 201 Substrate 102 Organic EL element 102a, 202 Anode 102b Organic EL layer 102c, 204 Cathode 103 Sealing film 205 Drive element 206 Hole transport layer 207 Light emitting layer 208 Electron transport layer 601 Substrate 602 TFT

Claims (12)

An organic semiconductor material comprising a compound represented by the following general formula (1):

[Wherein, A represents a condensed aromatic hydrocarbon ring or a condensed aromatic heterocyclic ring in which at least two rings are condensed, and Ar _{1 to} Ar ₄ each represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring. R _{1 to} R ₈ each represent a hydrogen atom, a halogen atom or a substituent, and may be connected to each other to form a ring. n represents 0 or 1. a and b each represent an integer of 0 to 3, and a and b satisfy the following relational expression (1). ]
Relational expression (1)
1 ≦ (a + b) The organic semiconductor material according to claim 1, wherein a and b satisfy the following relational expression (2).
Relational expression (2)
2 ≦ (a + b) The organic semiconductor material according to claim 1 or 2, wherein the compound represented by the general formula (1) has a weight average molecular weight in the range of 250 to 10,000. An organic semiconductor material comprising a compound represented by the following general formula (2):

[In the formula, Ar _{1 to} Ar ₇ each represents an aromatic hydrocarbon ring or an aromatic heterocycle, R _{1 to} R ₁₅ each represents a hydrogen atom, a halogen atom or a substituent, and each ring is linked to each other to form a ring. May be formed. n represents 0 or 1. a and b each represent an integer of 0 to 3, and a and b satisfy the following relational expression (1), c and d each represent an integer of 0 to 5 and c , D satisfies the following relational expression (3). ]
Relational expression (1)
1 ≦ (a + b)
Relational expression (3)
1 ≦ (c + d) The organic semiconductor material according to claim 4, wherein the a, b, c, and d satisfy the following relational expressions (4) and (5).
Relational expression (4)
2 ≦ (a + b)
Relational expression (5)
2 ≦ (c + d) The organic semiconductor material according to claim 4 or 5, wherein the compound represented by the general formula (2) has a weight average molecular weight in the range of 250 to 10,000. The organic semiconductor material according to claim 4, wherein each of Ar _{1 to} Ar ₇ represents an aromatic hydrocarbon ring. An organic semiconductor film comprising the organic semiconductor material according to claim 1. An organic semiconductor film formed by dissolving the organic semiconductor material according to any one of claims 1 to 7 in an organic solvent, and applying and drying the prepared solution. The organic-semiconductor device using the organic-semiconductor material of any one of Claims 1-7. An organic thin film transistor, wherein the organic semiconductor material according to claim 1 is used for a semiconductor layer. An organic electroluminescent element comprising the organic semiconductor device according to claim 10 or the organic thin film transistor according to claim 11.

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