JP2007088223A - Organic semiconductor material, organic semiconductor film, organic semiconductor device and organic thin film transistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor material that is manufactured through a simple process, excellent in characteristics as a transistor, and restrained from deteriorating with time, and to provide an organic semiconductor film using the same, an organic semiconductor device, and an organic thin film transistor. <P>SOLUTION: The organic semiconductor material is a compound equipped with a partial structure represented by formula (1). In the formula (1), R<SB>1</SB>and R<SB>2</SB>are independent from each other and denote hydrogen atoms or substituents, x is zero or an integer of one or more, and Ar is equipped with one or more arylene groups or hetero arylene groups of substitution or substitution-less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic semiconductor material, an organic semiconductor film, an organic semiconductor device, and an organic thin film transistor having high mobility and excellent durability.

  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, the opportunity to digitize information that has been provided in paper media has increased, and electronic paper or digital paper is used as a mobile display medium that is thin, light, and easy to carry. 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 multilayered. A TFT element is manufactured by sequentially forming source, drain, and gate electrodes on a 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 constructed 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 transistor elements (organic TFT elements) 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 tetracarboxylic acid. Low molecular weight compounds such as 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), 5-membered acenes A compound in which aromatic heterocycles are condensed symmetrically (for example, see Patent Document 4), mono, oligo, and polydithienopyridine (for example, see Patent Document 5), polythiophene, polythienylene vinylene, poly-p-phenylene vinylene Limited types of compounds such as conjugated polymers ( Example, there is only in Non-Patent Documents 1 to 3), while retaining sufficient solubility in solvents, sufficient carrier mobility, a material showing the ON / OFF ratio has not been found.

  Recently, it has been reported that a single crystal of rubrene, which is a highly soluble acene, has a very high mobility (see Non-Patent Document 4), but such a single crystal was produced by a vapor phase growth method. The film formed by solution casting is amorphous, and sufficient mobility is not obtained.

  In addition, a compound having a functional group added to pentacene, which is a compound having high carrier mobility by vacuum deposition, is disclosed, and it has been reported that relatively good carrier mobility can be obtained by solution coating (for example, (See Patent Document 6).

  However, it is known that acene-based compounds are easily oxidized by air and converted into an oxidant called endperoxide, which greatly degrades the performance as a field effect transistor. Storage stability in solution There are still problems to be solved regarding the stability of coating films.

  In terms of stability to oxygen, there is a tendency that oligothiophene compounds are relatively more stable than acene compounds, but oligothiophene compounds are also oxidized by oxygen and their performance deteriorates over time. The problem is known.

  With respect to the stability over time of such an organic semiconductor element, for example, Japanese Patent Application Laid-Open No. 2003-292588, US Patent Application Publication Nos. 2003/136958, 2003/160230, and 2003/164495. "Using polymer TFTs as integrated circuit logic elements for microelectronics greatly improves their mechanical durability and extends their useful life. However, many of the semiconductor polythiophenes are oxidized by surrounding oxygen. As a result of the increased conductivity, it is considered unstable when exposed to air, resulting in a higher off-current for devices made from these materials and thus a lower current ON / OFF ratio. Therefore, many of these materials eliminate environmental oxygen during material processing and device manufacturing. Care must be taken not to cause or minimize oxidative doping, as this precautionary measure increases manufacturing costs, and 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, and thus have a strong resistance to oxygen, There is a need for an electronic device that exhibits a relatively high current ON / OFF ratio, "as stated in the description of how to prevent deterioration of organic semiconductor materials over time. It has become a big issue.

  Various solutions have been proposed. For example, in Patent Documents 7 to 9, when a thienyl group having a substituent in polythiophene is placed at an appropriate interval, the planar structure of the polythiophene chain can be made intermittent, and oxidation can be suppressed. Disclosure.

  Further, in Patent Document 10, by using an oligothiophene-based compound having a thieno [2,3-b] thiophene structure, a structure in which charges cannot be delocalized through the thienothiophene structure similarly, oxygen stability is achieved. There are also reports that improvements will be made.

However, the mobility of these compounds is about 1.7 × 10 ⁻² cm ² / Vsec, which is not the mobility that can achieve the operating frequency required for an active matrix display, but sufficient performance and durability as an organic semiconductor. No compound has yet been found.

Therefore, the development of a semiconducting composition using a novel charge transporting material that is soluble in a solvent and has sufficient carrier mobility, ON / OFF ratio, and stability over time is awaited. Has been.
JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP-A-11-195790 JP 2003-155289 A International Publication No. 03/016599 Pamphlet JP 2003-261655 A JP 2003-264327 A JP 2003-268083 A JP-A-2005-76030 “Science” 289, 599 (2000) “Nature” 403, 521 (2000) Advanced Material, 2002, No. 2, page 99 Science, vol. 303 (2004), page 1644

  An object of the present invention is to provide an organic semiconductor material which is manufactured by a simple process, has good characteristics as a transistor, and further suppresses deterioration over time, an organic semiconductor film using the same, an organic semiconductor device, and an organic thin film transistor. That is.

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

  1. An organic semiconductor material, which is a compound having a partial structure represented by the following general formula (1).

(In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a substituent. X represents 0 or an integer of 1 or more. Ar represents a substituted or unsubstituted one or two or more arylene groups. Or a heteroarylene group.)
2. 2. The organic semiconductor material as described in 1 above, wherein the compound having a partial structure represented by the general formula (1) is a compound represented by the following general formula (2).

(In the formula, R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent. Ar represents an unsaturated hydrocarbon having one or more substituted or unsubstituted arylene groups or heteroarylene groups. N represents an integer of 1 to 100,000, and x represents 0 or an integer of 1 or more.)
3. 3. The organic semiconductor material as described in 1 or 2 above, wherein Ar has the same or different repeating units represented by the following general formula (3), and x is an integer of 1 to 10.

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom or a substituent.)
4). 4. The organic semiconductor material according to any one of 1 to 3, wherein the compound having a partial structure represented by the general formula (1) is a compound represented by the following general formula (4).

(In the formula, R ₇ to ₁₂ each independently represent a hydrogen atom or a substituent. Y represents an integer of 1 to 100,000.)
5. 5. The organic semiconductor material as described in 4 above, wherein Y is an integer of 1 to 20.

6). 6. The organic semiconductor material as described in 4 or 5 above, wherein R ₁₁ and R ₁₂ are substituted or unsubstituted phenyl groups.

  7). The organic-semiconductor film of any one of said 1-6 is contained, The organic-semiconductor film characterized by the above-mentioned.

  8). 7. An organic semiconductor device using the organic semiconductor material according to any one of 1 to 6 above.

  9. 7. An organic thin film transistor, wherein the organic semiconductor material according to any one of 1 to 6 is used for a semiconductor layer.

  According to the present invention, there are provided an organic semiconductor material that is manufactured by a simple process, has good characteristics as a transistor, and further suppresses deterioration over time, and an organic semiconductor film, an organic semiconductor device, and an organic thin film transistor using the organic semiconductor material. be able to.

  As a result of intensive studies, the present inventor has found that a compound having a specific structure defined in any one of claims 1 to 6 is an organic semiconductor material useful for thin film transistor applications. In addition, an organic semiconductor film, an organic semiconductor device, and an organic thin film transistor (hereinafter also referred to as an organic TFT) manufactured using the organic semiconductor material have excellent carrier mobility and excellent ON / OFF characteristics. It was found to be highly durable while exhibiting characteristics.

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

[Organic semiconductor materials]
The organic semiconductor material of the present invention is characterized by being a compound having a partial structure represented by the general formula (1). Conventionally, acene-based compounds, such as pentacene, are well known as organic semiconductor materials. However, since pentacene is insoluble, a film can be formed only by vapor deposition. difficult. In addition, even if an alkyl group or the like is added to solubilize pentacene as described in Patent Document 6, the acene-based compound is oxidized very quickly by oxygen and deteriorates the TFT performance. It cannot be used except for the film forming process. Further, the compound (rubrene) as disclosed in Non-Patent Document 4 is a highly soluble compound as an acene compound, but is oxidized by oxidation in a solution like other acene compounds. Therefore, there is a problem in the temporal stability.

  As materials other than acene-based materials, thiophene oligomers represented by unsubstituted 6T are also well known as organic semiconductor materials, but they are insoluble like pentacene and have a problem that a film can be formed only by vapor deposition. In addition, since the activity at the 4-position of the terminal thiophene is high, there was a problem in the temporal stability of the material and the coating film.

  Examples of the polymer include polyhexylthiophene (PHT) obtained by adding a hexyl group to polythiophene, Am. Chem. Soc. , Vol. 126 (2004), page 3378, or a structure in which the conjugated system extends only in a relatively narrow range, as described in Patent Documents 7 to 10, to a certain degree of acid resistance. Although it has been reported that the formation stability can be imparted, the formation of the π stack is insufficient, and there are many portions where the molecular arrangement is disordered, and yet satisfactory TFT performance has not been obtained.

  As a result of various studies on the above problems, the present inventors have found that the compound having the partial structure represented by the general formula (1) according to the present invention has both TFT performance, solution coating property, and oxidation resistance stability. It discovered that it was a compound and came to complete this invention.

  In the general formula (1), the thieno [3,2-b] thiophene moiety is a 10π aromatic ring in which two 5-membered rings are condensed and has a planar structure. In addition, although details are unknown, it has been found as a result of examination that it is easier to induce molecular orientation and has higher performance as a TFT than thieno [2,3-b] thiophene, which is a positional isomer of S atom. . Similarly to the thieno [2,3-b] thiophene structure described in Patent Document 10, π between the thieno [3,2-b] thiophene moiety and the Ar (arylene or heteroarylene) moiety in the general formula (1) The conjugated system cannot be completely delocalized, and the conjugated structure of the aromatic rings is cleaved by a relatively short unit, so that the ionization potential of the compound does not increase excessively and the compound is stable against oxidation. be able to.

  Ar has one or more arylene groups or heteroarylene groups. The arylene group or heteroarylene group may have a substituent.

  For example, aromatic hydrocarbon rings 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. Ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, pyranthrene ring, anthraanthrene ring, etc. It is done. Of these, a benzene ring is preferably used.

  Further, these aromatic hydrocarbon rings may be unsubstituted or have a substituent, and examples of the substituent include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert- Butyl group, pentyl group, 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 groups (eg ethynyl group, propargyl group etc.), aryl groups (eg phenyl group, naphthyl group etc.), aromatic heterocycles (eg furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group) , Pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl , Phthalazinyl group, etc.), heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyl group) Oxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, 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.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, phenylthio group, naphthylthio group, etc.), Lucoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group) ), Sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl 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, ethylcarbonyl group) Oxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, Pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino 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, ethylureido group, pentylureido group, cyclohexylureido) Group, octylureido group, dodecylureido group, phenylureido group naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (example) For example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl 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 (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, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.). These aromatic hydrocarbon rings may be unsubstituted or have a substituent.

  Aromatic heterocycles include furan ring, thiophene ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole At least one of the carbon atoms of the hydrocarbon ring constituting the ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring, carboline ring is further substituted with a nitrogen atom. Ring and the like. These aromatic heterocycles may be unsubstituted or have a substituent.

R ₁ and _{2 each} represents a hydrogen atom or a substituent. Examples of the substituent include an alkyl group (for example, methyl group, ethyl group, 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 (for example, ethynyl group, propargyl group, etc.), aryl group (for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocycle (for example, Furyl group, thienyl group, pyridyl group, pyridazi Group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, etc.), heterocyclic group (for example, 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.) , Cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group) Octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group) Butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminos Sulfonyl 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), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbo group) Ruamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino 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, ethylureido group, pentylureido group, cyclohexyl) Raid group, octylureido 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, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group) Group, dodecylsulfonyl group, etc.), arylsulfonyl group (eg, 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), halogen atom (For example, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, silyl group (for example, , Trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.). Among these, the substituent is preferably an alkyl group. These substituents may be further substituted with the above substituents, or a plurality thereof may be bonded to each other to form a ring.

More preferably, it is a compound represented by the said General formula (2). In the general formula (2), n represents an integer of ₁ to 100,000, and R _{1 to} R ₄ each independently represent a hydrogen atom or a substituent. Ar has one or more arylene groups or heteroarylene groups. The arylene group or heteroarylene group may have a substituent. For R ₁ ~ ₄ and Ar, include those described in R ₁ ~ ₂ and Ar, respectively, in the general formula (1).

Moreover, it is more preferable that Ar has the same or different repeating units represented by the general formula (3). In the general formula (3), m represents an integer of 1 to 100,000, and R ₅ to ₆ each independently represent a hydrogen atom or a substituent. Those described R ₁ ~ ₂ in the general formula (1) is enumerated as the substituent.

More preferably, it is a compound represented by the said General formula (4). Y is an integer of 1 to 100,000, preferably an integer of 1 to 20. R ₇ to ₁₂ each independently represent a hydrogen atom or a substituent. Those described R ₁ ~ ₂ in the general formula (1) is enumerated as the substituent. R ₁₁ and R ₁₂ are preferably a substituted or unsubstituted phenyl group.

  The precursor of the compound of the present invention may be used. A precursor is a compound intended to generate a hydrogen-bonding aromatic group by application of energy or chemical treatment. For example, a compound obtained by oxidizing a part of an aromatic ring with oxygen can be used, but the present invention is not limited to this.

  Hereinafter, although the specific example of the organic-semiconductor material of this invention is shown, this invention is not limited to these.

  Next, synthesis examples of these compounds are shown.

(Synthesis of Exemplified Compound 5)
Exemplary compound 5 was synthesized according to the following scheme.

  By reaction of raw material 1 and raw material 2 under Suzuki conditions (see M. Jayakannan, JLJ. Van Dongen, RAJ Janssen, Macromolecules, 2001, 34, 5386-5393) Intermediate 1 was obtained. Further, Example Compound 5 was obtained by the polymerization reaction of Intermediate 1.

  The molecular structure of the obtained compound 5 was measured by 1H-NMR (nuclear magnetic resonance spectrum) and mass spectrum, and confirmed to be consistent with the target product. Furthermore, it was confirmed that the purity was 99% or more from the result of HPLC measurement.

  Other compounds can be synthesized in the same manner.

[Organic semiconductor film, organic semiconductor device, organic thin film transistor]
The organic semiconductor film, organic semiconductor device, and organic thin film transistor of the present invention will be described.

  When the organic semiconductor material of the present invention is used for a semiconductor layer of an organic semiconductor film, an organic semiconductor device, or an organic thin film transistor, an organic semiconductor device and an organic thin film transistor that are driven well can be provided. An organic thin film transistor has a top gate type having a source electrode and a drain electrode connected with an organic semiconductor as a semiconductor layer on a support, and having a gate electrode on the support via a gate insulating layer. 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 through a gate insulating layer.

  In order to install the organic semiconductor material of the present invention on a semiconductor layer of an organic semiconductor film, an organic semiconductor device, or an organic thin film transistor, it can be installed on a substrate by vacuum deposition, but it can be dissolved in an appropriate solvent and added as necessary. It is preferable to place the solution prepared by adding the solution on the substrate by cast coating, spin coating, printing, inkjet method, ablation method or the like.

  In this case, the solvent for dissolving the organic semiconductor material of the present invention is not particularly limited as long as the organic semiconductor material can be dissolved to prepare a solution having an appropriate concentration, but specifically, diethyl ether or diisopropyl ether. Linear 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 And aromatic solvents such as 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 organic thin film transistor of the present invention, the organic semiconductor material of the present invention is preferably used for the semiconductor layer as described above. The semiconductor layer is preferably formed by applying a solution or dispersion containing these organic semiconductor materials. The solvent for dissolving the organic semiconductor material is preferably a solvent containing the non-halogen solvent, and is preferably composed of a non-halogen solvent.

  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 mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide mixtures, lithium / aluminum mixtures, etc. are used, especially platinum, gold, silver, copper, aluminum, indium, ITO and Carbon is preferred. Alternatively, a known conductive polymer whose conductivity is improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, conductive polythiophene, a complex of polyethylenedioxythiophene and polystyrenesulfonic acid, or the like is 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 from a conductive thin film formed using 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, the conductive polymer solution or dispersion, or the conductive fine particle dispersion may be directly patterned by ink jet, or may be formed from the coating film by lithography, laser ablation, or the like. 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 a relief printing plate, an intaglio printing plate, a planographic printing plate or a screen printing can 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 trioxide yttrium. 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 the like, spraying Examples include a wet process such as a coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a roll coating method, a bar coating method, a coating method such as a die coating method, and a patterning method such as printing or inkjet. 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 necessary, 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 an organic compound film, polyimide, polyamide, polyester, polyacrylate, photo radical polymerization type, photo cationic polymerization type photo-curing resin, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolac resin, and cyanoethyl Pullulan or the like can also 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 using the organic-semiconductor film formed using the organic-semiconductor material of this invention is demonstrated.

  FIG. 1 is a diagram showing a configuration example of an organic thin film transistor 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 an organic thin film 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. FIG. 2C shows a structure in which 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.

  FIG. 2 is a diagram showing an example of a schematic equivalent circuit diagram of an organic thin film transistor sheet.

  The organic thin film transistor sheet 10 has a large number of organic thin film transistors 11 arranged in a matrix. 7 is a gate bus line of each organic thin film transistor 11, and 8 is a source bus line of each organic thin film transistor 11. An output element 12 is connected to the source electrode of each organic thin film transistor 11, and this output 12 is, for example, a liquid crystal, an electrophoretic element or the like, 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.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. Unless otherwise specified, “%” in the examples represents “mass%”.

Example 1
<< Preparation of Organic TFT (Organic Thin Film Transistor) Element 1 >>: Comparative Example After forming a thermal oxide film having a thickness of 2000 mm on a Si wafer having a specific resistance of 0.01 Ω · cm as a gate electrode to form a gate insulating layer, octadecyl Surface treatment with trichlorosilane was performed. A chloroform solution of comparative compound 1 (rubrene, manufactured by Alidrich) was applied using an applicator, and naturally dried to form a cast film (thickness: 50 nm), followed by heat treatment at 50 ° C. for 30 minutes in a nitrogen atmosphere. gave.

  Further, gold was deposited on the surface of this film using a mask to form a source electrode and a drain electrode. An organic TFT device 1 having a source electrode and a drain electrode 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 produced.

<< Preparation of Organic TFT Elements 2-6 >>: Comparative Example Organic TFT elements 2-6 were prepared in the same manner as in the preparation of organic TFT element 1, except that Comparative Compound 1 was changed to Comparative Compounds 2-6.

<< Preparation of Organic TFT Elements 7 to 13 >>: Present Invention Organic TFT elements 7 to 13 were prepared in the same manner as the organic TFT element 1 except that the comparative compound 1 was changed to the organic thin film material of the present invention shown in Table 1. 13 was produced.

<< Evaluation of carrier mobility and ON / OFF ratio >>
About the obtained organic TFT elements 1-13, the carrier mobility and ON / OFF ratio of each element immediately after production and after being left in the atmosphere for 1 month were determined. 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.

  The obtained results are shown in Table 1.

  From Table 1, compared with the organic TFT element produced using the comparative organic thin film material, the organic TFT elements 7 to 13 produced using the organic thin film material of the present invention showed excellent transistor characteristics even immediately after production. In addition, it can be seen that it also has high durability with little deterioration with time.

Example 2
Moreover, the organic EL element using an organic thin-film transistor was produced as an application example of the organic thin-film transistor using the organic-semiconductor material of this invention.

<< 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 denotes a substrate, 102a denotes an anode, 102b denotes an organic EL layer (specifically, an electron transport layer, a light emitting layer, a hole transport layer, and the like), 102c denotes a cathode, and the 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. In the present invention, either a bottom emission type or a top emission type may be used.

  An active matrix light-emitting element is manufactured by combining an organic EL element and the organic thin film transistor of the present invention (here, the organic thin film transistor of the present invention is used as a switching transistor, a drive transistor, etc.). As shown in FIG. 4, an embodiment using 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 given 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 thin-film transistor of this invention. It is an example of the schematic equivalent circuit schematic of the organic thin-film transistor sheet 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 thin-film transistor sheet 11 Organic thin-film transistor 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 driving element 206 hole transport layer 207 light emitting layer 208 electron transport layer 601 substrate 602 TFT

Claims (9)

An organic semiconductor material, which is a compound having a partial structure represented by the following general formula (1).

(Wherein, .Ar .x representing the R ₁ and R ₂ are each independently of the other hydrogen or substituent represents 0 or an integer of 1 or more is one of substituted or unsubstituted, or two or more arylene groups Or a heteroarylene group.) The organic semiconductor material according to claim 1, wherein the compound having a partial structure represented by the general formula (1) is a compound represented by the following general formula (2).

(In the formula, R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent. Ar represents an unsaturated hydrocarbon having one or more substituted or unsubstituted arylene groups or heteroarylene groups. N represents an integer of 1 to 100,000, and x represents 0 or an integer of 1 or more.) The organic semiconductor material according to claim 1 or 2, wherein Ar has the same or different repeating units represented by the following general formula (3), and x is an integer of 1 to 10.

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom or a substituent.) The organic semiconductor material according to any one of claims 1 to 3, wherein the compound having a partial structure represented by the general formula (1) is a compound represented by the following general formula (4): .

(In the formula, R ₇ to ₁₂ each independently represent a hydrogen atom or a substituent. Y represents an integer of 1 to 100,000.) The organic semiconductor material according to claim 4, wherein Y is an integer of 1 to 20. 6. The organic semiconductor material according to claim 4, wherein R ₁₁ and R ₁₂ are substituted or unsubstituted phenyl groups. The organic-semiconductor film of any one of Claims 1-6 is contained, The organic-semiconductor film characterized by the above-mentioned. The organic-semiconductor device using the organic-semiconductor material of any one of Claims 1-6. An organic thin film transistor using the organic semiconductor material according to claim 1 for a semiconductor layer.

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