JP2010225974A - Organic semiconductor composite and organic field effect transistor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor composite stably achieving high mobility and on/off ratio, and also to provide an organic field effect transistor. <P>SOLUTION: The organic semiconductor composite contains carbon nanotubes and a plurality of organic semiconductors of ≤3,000 in molecular weight, which include at least: an organic semiconductor (A) with a molecular weight M(A); and an organic semiconductor (B) with a molecular weight M(B) comprising a partial structure of the organic semiconductor (A), M(A) and M(B) satisfying 2M(B)≥M(A). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic semiconductor composite containing a carbon nanotube and a plurality of organic semiconductors, and an organic field effect transistor.

  In recent years, an organic field effect transistor (hereinafter referred to as an organic FET) using an organic semiconductor having excellent moldability as a semiconductor layer has been proposed. By using an organic semiconductor as an ink, it becomes possible to form a circuit pattern directly on a substrate by an ink jet technique or a screening technique. Therefore, a field effect transistor (hereinafter referred to as FET) using a conventional inorganic semiconductor. Instead, organic FETs using organic semiconductors are being actively studied.

An important index indicating the performance of the FET element is mobility and on / off ratio. The improvement in mobility means that the on-current is increased. On the other hand, improving the on / off ratio means increasing the on-current and decreasing the off-current. Both of these improve the switching characteristics of the FET. For example, in a liquid crystal display device, high gradation is realized. For example, in the case of a liquid crystal display device, the mobility 0.1cm ² / V · sec or higher, the on-off ratio 10 ⁵ or more is required.

  As organic semiconductors used in FETs, organic low-molecular semiconductors such as acenes such as pentacene and tetracene (see, for example, Patent Document 1) and metal phthalocyanine compounds (see, for example, Patent Document 2) have been proposed. However, organic low molecular semiconductors often use a vacuum process such as vapor deposition, which makes it difficult to increase the area and reduce costs. Thus, organic polymer semiconductors such as conjugated polymers and polythiophenes are disclosed. As a technique for improving the mobility of an organic TFT using an organic polymer semiconductor, a method using a polymer composite having a conjugated polymer such as polythiophene and a carbon nanotube (for example, see Patent Document 3), organic Although a method using a solid composition in which nanorods or nanotubes are dispersed in semiconductor molecules (for example, see Patent Document 4) has been disclosed, none of them has achieved sufficient mobility. Therefore, an organic semiconductor composite containing a specific thiophene compound and a carbon nanotube has been proposed (see, for example, Patent Document 5).

JP-A-5-55568 (Claims) JP 2000-174277 A (Claims) JP 2006-265534 A (Claims) JP 2006-93699 A (Claims) International Publication No. 2008/090969 Pamphlet

  However, the organic low molecular weight semiconductor has a problem that crystals are likely to be formed at the time of thin film formation, carbon nanotubes are insufficiently dispersed, and it is difficult to stably obtain a high on / off ratio. Accordingly, an object of the present invention is to provide an organic semiconductor composite and an organic FET that can stably achieve both high mobility and an on / off ratio.

  The present invention is an organic semiconductor composite comprising carbon nanotubes and a plurality of organic semiconductors having a molecular weight of 3000 or less, wherein the plurality of organic semiconductors having a molecular weight of 3000 or less are at least an organic semiconductor (A) having a molecular weight M (A) and the organic semiconductor (A) An organic semiconductor (B) having a molecular weight M (B) composed of a partial structure of the organic semiconductor (A), wherein the M (A) and M (B) satisfy a relationship of 2M (B) ≧ M (A) It is a semiconductor composite.

  The present invention can provide an organic semiconductor composite and an organic FET that can stably obtain high charge mobility and high on / off ratio.

Schematic sectional view showing an organic FET which is one embodiment of the present invention Schematic sectional view showing an organic FET which is another embodiment of the present invention

  The organic semiconductor composite of the present invention contains a carbon nanotube (hereinafter referred to as CNT) and a plurality of organic semiconductors having a molecular weight of 3000 or less.

  As the CNT, a single-layer CNT in which one carbon film (graphene sheet) is wound in a cylindrical shape, a two-layer CNT in which two graphene sheets are wound in a concentric shape, and a plurality of graphene sheets are concentric in shape And multi-walled CNT wound around. In the present invention, any of these may be used, or two or more of them may be used. CNT can be obtained by an arc discharge method, a chemical vapor deposition method (CVD method), a laser ablation method, or the like.

  In the present invention, the length of the CNT is preferably shorter than the distance (channel length) between the source electrode and the drain electrode of the organic FET. The average length of CNT depends on the channel length, but is preferably 2 μm or less, more preferably 0.5 μm or less. In general, commercially available CNTs have a distribution in length, and CNTs longer than the channel length may be included. Therefore, it is preferable to provide a step of shortening the CNTs shorter than the channel length. For example, a method of cutting into short fibers by acid treatment with nitric acid, sulfuric acid or the like, ultrasonic treatment, or freeze pulverization is effective. Further, it is more preferable to use separation by a filter in view of improving purity. In the present invention, it is preferable to provide a step of uniformly dispersing CNT in a solvent and filtering the dispersion with a filter. By obtaining CNT smaller than the filter pore diameter from the filtrate, CNT shorter than the channel length can be obtained efficiently. In this case, a membrane filter is preferably used as the filter. The pore diameter of the filter used for filtration should just be smaller than channel length, and 0.5-10 micrometers is preferable.

  Moreover, the diameter of CNT is not specifically limited, However, 1 nm or more and 100 nm or less are preferable, More preferably, it is 50 nm or less.

  In the present invention, it is preferable to use CNT having a conjugated polymer attached to at least a part of its surface. Thereby, CNT can be more uniformly dispersed in the organic semiconductor, and the mobility and on / off ratio can be further improved. The state where the conjugated polymer is attached to at least a part of the surface of the CNT means a state where a part or all of the surface of the CNT is covered with the conjugated polymer. The reason why the conjugated polymer can coat CNT is presumed to be that interaction occurs due to the overlap of π electron clouds derived from the respective conjugated structures. Whether or not the CNT is coated with the conjugated polymer can be determined by approaching the color of the conjugated polymer from the color of the uncoated CNT. Quantitatively, the presence of deposits and the weight ratio of deposits to CNTs can be identified by elemental analysis such as X-ray photoelectron spectroscopy (XPS). Hereinafter, CNT having a conjugated polymer attached to at least a part of the surface is referred to as a CNT composite.

  The method for adhering a conjugated polymer to CNT is as follows: (I) a method in which CNT is added and mixed in a molten conjugated polymer; (II) a conjugated polymer is dissolved in a solvent; (III) A method in which CNT is preliminarily dispersed in a solvent with ultrasonic waves or the like, and a conjugated polymer is added thereto and mixed. (IV) A conjugated polymer in the solvent. And CNT, and a method of mixing the mixed system by irradiating ultrasonic waves. In the present invention, any method may be used, and any method may be combined.

  Examples of the conjugated polymer attached to the CNT include a polythiophene polymer, a polypyrrole polymer, a polyaniline polymer, a polyacetylene polymer, a poly-p-phenylene polymer, and a poly-p-phenylene vinylene polymer. However, it is not particularly limited. In addition, as the polymer, those in which single monomer units are arranged are preferably used, but those obtained by block copolymerization, random copolymerization, or graft polymerization of different monomer units can also be used. Among the above-mentioned polymers, in the present invention, a polythiophene polymer that is easily attached to CNT and easily forms a CNT composite is particularly preferably used.

  The polythiophene polymer refers to a polymer having a poly-thiophene structure skeleton, and includes a polymer having a side chain. Specific examples include poly-3-alkylthiophene (alkyl group) such as poly-3-methylthiophene, poly-3-butylthiophene, poly-3-hexylthiophene, poly-3-octylthiophene, poly-3-dodecylthiophene, and the like. Is preferably 1-12); poly-3-alkoxythiophene such as poly-3-methoxythiophene, poly-3-ethoxythiophene, poly-3-dodecyloxythiophene (the carbon number of the alkoxy group is preferably 1) -12); poly-3-alkoxy-4-alkylthiophene such as poly-3-methoxy-4-methylthiophene, poly-3-dodecyloxy-4-methylthiophene (the number of carbons of the alkoxy group and the alkyl group is preferably 1-12); poly-3-thiohexylthiophene and poly-3-thiodode Poly-3-thio-alkylthiophene such as Le thiophene (number of carbon atoms in the alkyl group is preferably 1 to 12) are exemplified. Two or more of these may be used. Among these, poly-3-alkylthiophene or poly-3-alkoxythiophene is preferable. As the former, poly-3-hexylthiophene is particularly preferable. The preferred molecular weight of the polythiophene polymer is 800 to 100,000 in terms of number average molecular weight.

  The method for removing impurities of the conjugated polymer used in the present invention is not particularly limited, but is basically a purification step for removing raw materials and by-products used in the synthesis process, reprecipitation method, Soxhlet extraction method, A filtration method, an ion exchange method, a chelate method, or the like can be used. In particular, when removing low molecular weight components, a reprecipitation method or Soxhlet extraction method is preferably used, and for removing metal components, a reprecipitation method, a chelate method, or an ion exchange method is preferably used. Two or more of these methods may be combined.

  The organic semiconductor in the present invention can be isolated and identified as a single compound having no molecular weight distribution and has a molecular weight of 3000 or less. Such an organic semiconductor can be purified by a method such as column purification, recrystallization, sublimation purification, or the like, and thus can be highly purified. Therefore, a high-performance FET can be obtained by using the single organic semiconductor that can be highly purified as a semiconductor layer. Furthermore, when the molecular weight is 3000 or less, the conjugated length of the organic semiconductor molecules can be suppressed, so that the stability against oxidation is improved. The molecular weight can be measured with a mass spectrometer generally used.

  The organic semiconductor composite of the present invention contains a plurality of organic semiconductors having a molecular weight of 3000 or less. The plurality of organic semiconductors having a molecular weight of 3000 or less contain at least an organic semiconductor (A) having a molecular weight M (A) and an organic semiconductor (B) having a molecular weight M (B) composed of a partial structure of the organic semiconductor (A). The M (A) and the M (B) satisfy the relationship of 2M (B) ≧ M (A). By containing the organic semiconductor (B) having a partial structure in addition to the organic semiconductor (A), the crystallinity of the organic semiconductor (A) can be suppressed, and the CNT can be uniformly dispersed even in a coating process such as inkjet. A semiconductor thin film can be produced. Thereby, an FET element having high mobility and an on / off ratio can be stably obtained. Note that the organic semiconductor (B) has a partial structure of the organic semiconductor (A) means that the organic semiconductor (B) has a structure in which a part of the structure of the organic semiconductor (A) is taken out and a hydrogen atom is bonded to the terminal. It means to match the structure. Furthermore, when the molecular weight M (A) of the organic semiconductor (A) and the molecular weight M (B) of the organic semiconductor (B) satisfy the relationship of 2M (B) ≧ M (A), the commonality of both structures is appropriate. The crystallinity of the organic semiconductor (A) can be appropriately adjusted. For this reason, the high mobility of the organic semiconductor (A) is maintained. Note that since the organic semiconductor (B) has a partial structure of the organic semiconductor (A), M (B) <M (A).

  The organic semiconductor (A) used in the present invention is preferably represented by the following general formula (1). By having a thiophene skeleton in the structure, high mobility can be obtained.

Here, X ¹ represents a divalent linking group composed of a single bond, vinylene group, ethynylene group, azo group, azomethine group, ether group, arylene group, heteroarylene group, or a combination thereof. Y ¹ and Y ² may be the same or different and each represents a group represented by the following general formula (2).

In the general formula (2), R ^{1 to} R ⁵ may be the same or different and are each hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group, Alkylthio group, aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen atom, cyano group, formyl group, carbamoyl group, amino group, alkylcarbonyl group, arylcarbonyl group, carboxyl group, alkoxycarbonyl group, aryloxy A carbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group or a silyl group; The ^R 1 to R ² or ^R 3 to R ⁵ adjacent may be bonded to form a ring structure. n represents an integer of 0 to 10.

Of X ¹ in the general formula (1), the arylene group represents a divalent group derived from an aromatic hydrocarbon such as benzene, naphthalene, biphenyl, phenanthrene, terphenyl, pyrene, and the like, and has a substituent. It may or may not have. There is no restriction | limiting in particular in the additional substituent in the case of having a substituent, For example, an alkyl group, an alkoxy group, a cycloalkyl group, a halogen atom etc. are mentioned. Moreover, although carbon number of an arylene group is not specifically limited, Usually, it is the range of 6-30.

  The heteroarylene group refers to a divalent group derived from an aromatic group having one or more atoms other than carbon in the ring, such as pyridine, benzofuran, dibenzothiophene, carbazole, benzoxadiazole, quinoxaline, and the like. . The heteroarylene group may or may not have a substituent. There is no restriction | limiting in particular in the additional substituent in the case of having a substituent, For example, an alkyl group, an alkoxy group, a cyano group, a formyl group etc. are mentioned. Moreover, although carbon number of heteroarylene group is not specifically limited, Usually, it is the range of 4-30.

Among R ^{1 to} R ⁵ in the general formula (2), examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. Of the saturated aliphatic hydrocarbon group, and may or may not have a substituent. In the case of having a substituent, the additional substituent is not particularly limited, and examples thereof include an alkoxy group, an aryl group, a heteroaryl group, and the like, and these may further have a substituent. . The number of carbon atoms of the alkyl group is not particularly limited, but is usually in the range of 1 to 20 and more preferably 1 to 8 from the viewpoint of availability and cost.

  The cycloalkyl group represents, for example, a saturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and may or may not have a substituent. In the case of having a substituent, the substituent is not particularly limited, and examples thereof include an alkyl group, an alkoxy group, an aryl group, and a heteroaryl group. These substituents may further have a substituent. . The explanation regarding these substituents is common to the following descriptions. Although carbon number of a cycloalkyl group is not specifically limited, Usually, it is the range of 3-20.

  The heterocyclic group refers to a group derived from an aliphatic ring having atoms other than carbon, such as a pyran ring, a piperidine ring, an amide ring, in the ring, and it may or may not have a substituent. Also good. Although carbon number of a heterocyclic group is not specifically limited, Usually, it is the range of 2-20.

  An alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond such as a vinyl group, an allyl group, or a butadienyl group, and may or may not have a substituent. Although carbon number of an alkenyl group is not specifically limited, Usually, it is the range of 2-20.

  The cycloalkenyl group refers to, for example, an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, a cyclohexenyl group, and has a substituent. It does not have to be. Although carbon number of a cycloalkenyl group is not specifically limited, Usually, it is the range of 3-20.

  An alkynyl group refers to, for example, an unsaturated aliphatic hydrocarbon group containing a triple bond such as an ethynyl group, and may or may not have a substituent. Although carbon number of an alkynyl group is not specifically limited, Usually, it is the range of 2-20.

  An alkoxy group refers to a functional group obtained by substituting one of the ether bonds with an aliphatic hydrocarbon group, such as a methoxy group, an ethoxy group, or a propoxy group, and the aliphatic hydrocarbon group may have a substituent. You don't have to. Although carbon number of an alkoxy group is not specifically limited, Usually, it is the range of 1-20.

  The alkylthio group is a group in which an oxygen atom of an ether bond of an alkoxy group is substituted with a sulfur atom. The aliphatic hydrocarbon group of the alkylthio group may or may not have a substituent. Although carbon number of an alkylthio group is not specifically limited, Usually, it is the range of 1-20.

  An aryl ether group refers to a functional group obtained by substituting one of the ether bonds with an aromatic hydrocarbon group, such as a phenoxy group or a naphthoxy group. The aromatic hydrocarbon group has a substituent even if it has a substituent. It does not have to be. Although carbon number of an aryl ether group is not specifically limited, Usually, it is the range of 6-40.

  An aryl thioether group is one in which the oxygen atom of the ether bond of the aryl ether group is substituted with a sulfur atom. The aromatic hydrocarbon group of the arylthioether group may or may not have a substituent. The number of carbon atoms of the arylthioether group is not particularly limited, but is usually in the range of 6 or more and 40 or less.

  The aryl group is, for example, an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, an anthracenyl group, a phenanthryl group, a terphenyl group, or a pyrenyl group, and it does not have a substituent. May be. Although carbon number of an aryl group is not specifically limited, Usually, it is the range of 6-40.

  The heteroaryl group refers to an aromatic group having one or more atoms other than carbon in the ring, such as furanyl group, thiophenyl group, benzofuranyl group, dibenzofuranyl group, pyridyl group, quinolinyl group, and the like. It may or may not have. Although carbon number of a heteroaryl group is not specifically limited, Usually, it is the range of 2-30.

  The halogen atom represents fluorine, chlorine, bromine or iodine.

  The carbamoyl group, amino group, and silyl group may or may not have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group. These substituents may be further substituted.

  The alkylcarbonyl group refers to a functional group obtained by substituting one of the carbonyl bonds with an aliphatic hydrocarbon group, such as an acetyl group or a hexanoyl group. The aliphatic hydrocarbon group has a substituent even if it has a substituent. It does not have to be. Although carbon number of an alkylcarbonyl group is not specifically limited, Usually, it is the range of 2-20.

  An arylcarbonyl group refers to a functional group obtained by substituting one of carbonyl bonds with an aromatic hydrocarbon group, such as a benzoyl group, and the aromatic hydrocarbon group may or may not have a substituent. Good. Although carbon number of an arylcarbonyl group is not specifically limited, Usually, it is the range of 7-40.

  The alkoxycarbonyl group refers to a functional group obtained by substituting one of carbonyl bonds with an alkoxy group, such as a methoxycarbonyl group, and the alkoxy group may or may not have a substituent. Although carbon number of an alkoxycarbonyl group is not specifically limited, Usually, it is the range of 2-20.

  The aryloxycarbonyl group refers to a functional group in which one of carbonyl bonds is substituted with an aryloxy group, such as a phenoxycarbonyl group, and the aryloxy group may or may not have a substituent. Although carbon number of an aryloxycarbonyl group is not specifically limited, Usually, it is the range of 7-40.

  The alkylcarbonyloxy group refers to a functional group obtained by substituting one of the ether bonds with an alkylcarbonyl group, such as an acetoxy group, and the alkylcarbonyl group may or may not have a substituent. The number of carbon atoms of the alkylcarbonyloxy group is not particularly limited, but is usually in the range of 2 or more and 20 or less.

  The arylcarbonyloxy group refers to a functional group obtained by substituting one of the ether bonds with an arylcarbonyl group, such as a benzoyloxy group, and the arylcarbonyl group may or may not have a substituent. The number of carbon atoms of the arylcarbonyloxy group is not particularly limited, but is usually in the range of 7 or more and 40 or less.

If bonded together adjacent groups form a ring, will be described by the general formula (2), any two adjacent groups selected from among R ¹ to R ⁵ (e.g. R ¹ and R ²⁾ to each other Combine to form a conjugated or non-conjugated fused ring. As a constituent element of the condensed ring, in addition to carbon, nitrogen, oxygen, sulfur, phosphorus and silicon atoms may be contained, or further condensed with another ring.

n represents an integer of 0 to 10. Furthermore, it is preferable that n is an integer of 0 to 7 because stability to oxidation and ease of synthesis are further improved. Further, when n is 2 or more, each R ¹ and R ² may be the same or different.

In consideration of suitability for the coating process, it is preferable that at least one of R ^{1 to} R ⁵ is an alkyl group or an alkoxy group having 4 or more carbon atoms.

When the organic semiconductor (A) is represented by the following general formula (1), the structure of the organic semiconductor (B) composed of the partial structure is preferably Y ¹ -X ¹ -H. By having such a structure, the crystallinity can be further easily controlled, and a high on / off ratio can be stably obtained.

  The organic semiconductor composite of the present invention may contain two or more organic semiconductors (A) and organic semiconductors (B).

  Examples of the organic semiconductor (A) represented by the general formula (1) include the following structures.

  Moreover, when the compound (1) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  When the compound (24) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  When the compound (36) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  When the compound (37) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  When the compound (60) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  When the compound (62) is an organic semiconductor (A), examples of the organic semiconductor (B) include the following structures.

  The organic semiconductor used in the present invention can be synthesized by a known method. For example, as a method of linking thiophenes, a method of coupling halogenated thiophene and thiophene boronic acid or thiophene boronic acid ester under palladium catalyst, coupling of halogenated thiophene and thiophene Grignard reagent under nickel or palladium catalyst The method of doing is mentioned. Also, when thiophene is linked to other units, coupling can be performed in the same manner using halogenated units.

  The organic semiconductor used in the present invention preferably removes impurities such as raw materials and by-products used in the synthesis process, and for example, silica gel columnography, recrystallization, filtration, and the like can be used. Two or more of these methods may be combined.

  In the present invention, the content of the organic semiconductor (B) is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and more preferably 30 parts by weight or less with respect to 100 parts by weight of the organic semiconductor (A). By setting the content of the organic semiconductor (B) to 100 parts by weight or less, a higher on / off ratio can be stably obtained. Moreover, 5 weight part or more is preferable and a mobility can be improved more.

  The content of CNT in the organic semiconductor composite is preferably 0.01 parts by weight or more and 3 parts by weight or less, and more preferably 1 part by weight or less with respect to 100 parts by weight of the organic semiconductor. Here, when the CNT composite is used as the CNT, the content of the CNT composite is defined as the CNT content. Further, the total content of all organic semiconductors having a molecular weight of 3000 or less including the organic semiconductors (A) and (B) is 100 parts by weight.

  As a manufacturing method of the organic-semiconductor composite of this invention, the method of mixing the solution containing CNT or CNT, and an organic semiconductor or its solution can be mentioned, for example. Moreover, you may add the process of the heating or ultrasonic irradiation for accelerating mixing as needed, and the process of removing solid components, such as filtration.

  Since the organic semiconductor composite of the present invention has a high charge transport capability, it is suitably used as an organic transistor material.

  Next, an organic FET using the organic transistor material of the present invention will be described. The organic FET of the present invention is an organic field effect transistor having a gate electrode, an insulating layer, a semiconductor layer, a source electrode and a drain electrode, and the semiconductor layer contains the organic semiconductor composite of the present invention.

  1 and 2 are schematic cross-sectional views showing examples of the organic FET of the present invention. In FIG. 1, a source electrode 5 and a drain electrode 6 are formed on a substrate 1 having a gate electrode 2 covered with an insulating layer 3, and a semiconductor layer 4 containing the organic semiconductor composite of the present invention is formed thereon. Has been. In FIG. 2, a semiconductor layer 4 containing the organic semiconductor composite of the present invention is formed on a substrate 1 having a gate electrode 2 covered with an insulating layer 3, and a source electrode 5 and a drain electrode 6 are further formed thereon. ing.

  Examples of the material used for the substrate 1 include inorganic materials such as silicon wafers, glass and alumina sintered bodies, and organic materials such as polyimide, polyester, polycarbonate, polysulfone, polyethersulfone, polyethylene, polyphenylene sulfide, and polyparaxylene. Can be mentioned.

  Examples of materials used for the gate electrode 2, the source electrode 5, and the drain electrode 6 include conductive metal oxides such as tin oxide, indium oxide, and indium tin oxide (ITO), platinum, gold, silver, copper, iron, Inorganic conductivity such as tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, magnesium, palladium, molybdenum, metals such as amorphous silicon and polysilicon, alloys thereof, copper iodide, copper sulfide Examples include, but are not limited to, materials, polythiophene, polypyrrole, polyaniline, and a conductive polymer whose conductivity has been improved by doping with iodine or the like, such as a complex of polyethylenedioxythiophene and polystyrenesulfonic acid. A plurality of materials may be laminated or mixed.

  Examples of the method for forming the gate electrode 2, the source electrode 5, and the drain electrode 6 include resistance heating vapor deposition, electron beam beam, sputtering, plating, CVD, ion plating coating, ink jet, and printing. If it is possible, there is no particular limitation. As an electrode pattern forming method, the electrode thin film produced by the above method may be formed into a desired shape by a known photolithography method, or a mask having a desired shape may be formed at the time of electrode material vapor deposition or sputtering. A pattern may be formed through the pattern.

  The material used for the insulating layer 3 (gate insulating film) is not particularly limited, but inorganic materials such as silicon oxide and alumina, polyimide, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, polyvinylphenol ( PVP) and the like, or a mixture of inorganic material powder and organic polymer material. The film thickness of the insulating layer 3 is preferably 50 nm to 3 μm, more preferably 100 nm to 1 μm. The insulating layer may be a single layer or a plurality of layers. One layer may be formed from a plurality of insulating materials, or a plurality of insulating materials may be stacked to form a plurality of insulating layers.

  The method for forming the insulating layer is not particularly limited, and examples thereof include resistance heating vapor deposition, electron beam beam, sputtering, CVD, ion plating, coating, ink jet, and printing, which can be used depending on the material.

  In the organic FET of the present invention, the semiconductor layer 4 contains the organic semiconductor composite of the present invention. Further, an insulating material may be included. Examples of the insulating material used here include poly (methyl methacrylate), polycarbonate, and polyethylene terephthalate, but are not particularly limited thereto.

  The thickness of the semiconductor layer 4 is preferably 5 nm or more and 100 nm or less. By setting the film thickness within this range, it is easy to form a uniform thin film, and further, the source-drain current that cannot be controlled by the gate voltage can be suppressed, and the on / off ratio of the organic FET can be further increased. The film thickness can be measured by an atomic force microscope or an ellipsometry method. The semiconductor layer 4 may be a single layer or a plurality of layers. In the case of a plurality of layers, the plurality of organic semiconductor composites of the present invention may be laminated, or the organic semiconductor composite of the present invention and a known organic semiconductor may be laminated.

  As a method for forming the semiconductor layer 4, dry methods such as resistance heating vapor deposition, electron beam, sputtering, and CVD can be used. However, a coating method is used from the viewpoint of manufacturing cost and adaptation to a large area. preferable. Specifically, a spin coating method, a blade coating method, a slit die coating method, a screen printing method, a bar coater method, a mold method, a printing transfer method, a dip pulling method, an ink jet method, etc. can be preferably used, and the coating thickness control The coating method can be selected according to the properties of the coating film to be obtained, such as the orientation control. For example, when spin coating is performed, a coating film having a thickness of 5 to 200 nm can be obtained when the concentration of the organic semiconductor composite solution is 1 to 20 g / l. At this time, as a solvent for dissolving the organic semiconductor composite, tetrahydrofuran, toluene, xylene, 1,2,3-trimethylbenzene, 1,2,3,5-tetramethylbenzene, 1,3-diethylbenzene, 1,4- Diethylbenzene, 1,3,5-triethylbenzene, 1,3-diisopropylbenzene, 1,4-isopropylbenzene, 1,4-dipropylbenzene, butylbenzene, isobutylbenzene, 1,3,5-triisopropylbenzene, dichloromethane , Dichloroethane, chloroform, chlorobenzene, dichlorobenzene, o-chlorotoluene, 1,2-dihydronaphthalene, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, ethyl 2,4,6-trimethylbenzoate, 2- Ethyl ethoxybenzoate, - toluidine, m- toluidine and p- toluidine and the like. Two or more of these solvents may be used. In addition, the formed coating film may be annealed in the air, under reduced pressure, or in an inert gas atmosphere (in a nitrogen or argon atmosphere).

  In addition, a buffer layer may be provided between the insulating layer 3 and the semiconductor layer 4. The organic semiconductor composite of the present invention exhibits high mobility even without a buffer layer. However, the provision of a buffer layer is preferable because higher mobility is possible. For the buffer layer, known materials such as a silane compound, a titanium compound, an organic acid, and a heteroorganic acid can be used, and among them, an organic silane compound is preferable.

  The organic silane compound is not particularly limited, and specifically, phenyltrichlorosilane, naphthyltrichlorosilane, anthracentrichlorosilane, pyrenetrichlorosilane, perylenetrichlorosilane, coronenetrichlorosilane, thiophenetrichlorosilane, pyrroletrichlorosilane, pyridinetrichlorosilane. Chlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, naphthyltrimethoxysilane, naphthyltriethoxysilane, anthracentrimethoxysilane, anthracentriethoxysilane, pyrenetrimethoxysilane, pyrenetriethoxysilane, thiophenetrimethoxysilane, thiophenetriethoxy Silane, phenylmethyltrichlorosilane, phenylethyltrichlorosilane, phenylpropylto Chlorosilane, phenylbutyltrichlorosilane, phenylhexyltrichlorosilane, phenyloctyltrichlorosilane, naphthylmethyltrichlorosilane, naphthylethyltrichlorosilane, anthracenemethyltrichlorosilane, anthraceneethyltrichlorosilane, pyrenemethyltrichlorosilane, pyreneethyltrichlorosilane, thiophenemethyltri Chlorosilane, thiopheneethyltrichlorosilane, aminophenyltrichlorosilane, hydroxyphenyltrichlorosilane, chlorophenyltrichlorosilane, dichlorophenyltrichlorosilane, trichlorophenyltrichlorosilane, bromophenyltrichlorosilane, fluorophenyltrichlorosilane, difluorophenyltrichlorosilane, trifluorosilane Alkenyl trichlorosilane, tetrafluorophenyl trichlorosilane, pentafluorophenyl trichlorosilane, iodophenyl trichlorosilane, and the like cyanophenyl trichlorosilane.

  Considering the resistance of the buffer layer, the thickness of the buffer layer is preferably 10 nm or less, more preferably a monomolecular film. The buffer layer also includes, for example, a layer formed by chemically bonding the organosilane compound and the insulating layer surface. A dense and strong film can be formed by the chemical reaction between the silyl group and the surface of the insulating layer. If an unreacted silane compound is laminated on the strong film after the reaction, the unreacted silane compound is removed by washing, etc., and the silyl group and the insulating layer surface are chemically bonded. Thus, a monomolecular film formed can be obtained.

  The method for forming the buffer layer is not particularly limited, and examples thereof include a vapor phase method such as a CVD method, and a method using a liquid phase such as a spin coating method and a dip pulling method.

  Before forming the buffer layer, the surface of the insulating layer serving as a base may be subjected to a hydrophilic treatment using a method such as a UV ozone method or an oxygen plasma method. Thereby, the chemical reaction between the silyl group and the insulating layer surface can be facilitated.

  The organic FET thus formed can control the current flowing between the source electrode and the drain electrode by changing the gate voltage. The mobility of the organic FET can be calculated using the following equation (a).

μ = (δId / δVg) L · D / (W · ε r · ε · Vsd) (a)
Where Id is the source-drain current (A), Vsd is the source-drain voltage (V), Vg is the gate voltage (V), D is the thickness of the insulating layer (m), and L is the channel length (m). , W is the channel width (m), ε _r is the dielectric constant of the insulating layer (here, 3.9 of SiO ₂ or 3.8 of PVP is used), and ε is the dielectric constant of vacuum (8.85 × 10 ^{− 12} F / m).

  Further, the on / off ratio can be obtained from the ratio of the value of Id (on current) at a certain negative gate voltage to the value of Id (off current) at a certain positive gate voltage.

Hysteresis is the difference between the gate voltage Vg ¹ at Id = 10 ⁻⁸ when Vg is applied from positive to negative and the gate voltage Vg ² at Id = 10 ⁻⁸ when Vg is applied from negative to positive. The absolute value | Vg ¹ −Vg ² |

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited by these Examples. In addition, the number of the compound in each following Example points out the number of the compound described in the above chemical formula.

¹ H-NMR for identification of the synthetic compound was measured with a deuterated chloroform solution using superconducting FT-NMR “EX-270” (manufactured by JEOL Ltd.).

Synthesis Example 1 (Synthesis of Compound (1))
12.3 g of p-bromobenzyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) and 18.0 g of triethyl phosphite (manufactured by Wako Pure Chemical Industries, Ltd.) were refluxed at 130 ° C. for 5 hours under a nitrogen stream. After cooling to room temperature, 65 ml of dimethyl sulfoxide was added, and 7.8 g of potassium tert-butoxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred for 30 minutes. To this was added 10.9 g of p-bromobenzaldehyde (manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was stirred at room temperature for 14 hours. The solid produced by adding 200 ml of water was collected by filtration to obtain 4.50 g of 4,4′-dibromo-2,2′-stilbene.

  60 g of 3-n-hexylthiophene (manufactured by Tokyo Kasei Kogyo Co., Ltd.) is dissolved in 400 ml of dimethylformamide, 50 g of N-bromosuccinimide (manufactured by Wako Pure Chemical Industries, Ltd.) is added, and the nitrogen atmosphere is used at room temperature. Stir for 4 hours. 200 ml of water and 200 ml of hexane were added to the resulting solution, and the organic layer was separated. After washing with 200 ml of water, it was dried over magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain 60 g of 2-bromo-3-n-hexylthiophene.

  Next, 4.34 g of magnesium powder and 10 mg of iodine were added to 100 ml of tetrahydrofuran and stirred for 30 minutes under a nitrogen atmosphere. A mixed solution of 42 g of 2-bromo-3-n-hexylthiophene and 100 ml of tetrahydrofuran was added dropwise thereto, and the mixture was heated to reflux for 1 hour. After cooling to room temperature, a mixed solution of 20 g of 5,5′-dibromo-2,2′-bithiophene and 200 ml of tetrahydrofuran was added, and further diphenylphosphinopropanenickel (II) dichloride (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.48 g Was added little by little, and the mixture was heated to reflux for 3 hours under a nitrogen atmosphere. To the obtained solution, 800 ml of 1N aqueous ammonium chloride solution and 600 ml of hexane were added, and the organic layer was separated. The extract was washed with 200 ml of a saturated aqueous sodium hydrogen carbonate solution and 200 ml of water, and then dried over magnesium sulfate. The resulting solution was concentrated by a rotary evaporator and purified by column chromatography (filler: silica gel, eluent: hexane) to obtain 28 g of 4T represented by the following formula.

  After cooling a mixed solution of 16.3 g of the above 4T and 20 ml of tetrahydrofuran to −30 ° C., 20.8 ml of n-butyllithium solution (1.6 mol / L hexane solution) was added dropwise and stirred at room temperature for 1 hour. The mixed solution was cooled to −10 ° C., 2-isoporopoxy-4,4,5,5-tetramethyl-1,2,3-dioxaborolane (5.73 g) was added, and the mixture was stirred at room temperature for 3 hours. To the obtained solution, 33 ml of 1N hydrochloric acid aqueous solution, 200 ml of water and 200 ml of dichloromethane were added, and the organic layer was separated. After washing with 100 ml of water, it was dried over magnesium sulfate. The obtained solution was concentrated with a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 11.5 g of 4T-BPin represented by the following formula.

To a mixed solution of 1.6 g of the above 4T-BPin, 0.34 g of 4,4′-dibromostilbene and 50 ml of toluene, 10 ml of ethanol, 15 ml of 2N sodium carbonate aqueous solution and tetrakis (triphenylphosphine) palladium (0) ((stock ) Tokyo Chemical Industry Co., Ltd.) 31 mg was added and refluxed at 110 ° C. for 9 hours under a nitrogen stream. The solid precipitated in the resulting solution was collected by filtration, washed with 20 ml of water, 20 ml of ethanol, and 20 ml of toluene, and then recrystallized from toluene. After vacuum drying, 0.90 g of orange powder was obtained. The results of ¹ H-NMR analysis of the obtained powder are as follows and confirmed to be compound (1).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.89-0.93 (t, 12H), 1.26-1.42 (m, 24H), 1.57-1.68 (m, 8H), 2.74-2.82 (m, 8H), 6.93-6.96 (m, 6H), 7.02 (d, 2H), 7.06 (d, 2H), 7.13 -7.24 (m, 8H), 7.52-7.63 (dd, 8H).

Synthesis Example 2 (Synthesis of Compound (69))
Benzyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) 8.80 g and triethyl phosphite 17.6 g were refluxed at 130 ° C. for 4.5 hours under a nitrogen stream. After cooling to room temperature, 65 ml of dimethyl sulfoxide was added, 7.6 g of potassium tert-butoxide was added, and the mixture was stirred for 30 minutes. 10.6-g of p-bromobenzaldehyde was added here, and it stirred at room temperature for 12 hours. 200 ml of water was added and the resulting solid was collected by filtration to obtain 4.13 g of 4-bromostilbene.

To a mixed solution of 1.6 g of 4T-BPin, 0.60 g of 4-bromostilbene and 50 ml of toluene, 10 ml of ethanol, 15 ml of 2N sodium carbonate aqueous solution and 35 mg of tetrakis (triphenylphosphine) palladium (0) were added, and nitrogen stream The mixture was refluxed at 110 ° C. for 5 hours. 100 ml of water and 150 ml of toluene were added, and the organic layer was separated. The extract was washed with 200 ml of saturated brine and dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator, and the residue was purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane). After vacuum drying, 1.1 g of orange powder was obtained. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (69).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.89-0.93 (t, 6H), 1.26-1.42 (m, 12H), 1.57-1.68 (m, 4H), 2.74-2.82 (m, 4H), 6.93-6.96 (m, 3H), 7.02 (d, 2H), 7.06 (d, 1H), 7.13 -7.24 (m, 4H), 7.52-7.72 (dd, 8H).

Synthesis Example 3 (Synthesis of Compound (24))
8.0 g of thiophene (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 150 ml of tetrahydrofuran and cooled to 0 ° C. 62.0 ml of n-butyllithium solution (1.6 mol / l hexane solution) was added dropwise thereto and stirred for 3 hours. 25.0 g of n-dodecyl bromide (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise and stirred at room temperature for 18 hours. To the obtained solution, 150 ml of water and 150 ml of dichloromethane were added, and the organic layer was separated. After washing with 300 ml of water, it was dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator, and then 12.9 g of 2-n-dodecylthiophene was obtained by distillation under reduced pressure.

  8.00 g of 2-n-dodecylthiophene was dissolved in 100 ml of tetrahydrofuran and cooled to -80 ° C. To this, 20.0 ml of n-butyllithium solution (1.6 mol / l hexane solution) was added dropwise and stirred for 4 hours. The temperature was raised to −30 ° C., 6.63 g of 2-isoporopoxy-4,4,5,5-tetramethyl- [1,3,2] dioxaborolane was added dropwise, and the mixture was stirred at room temperature for 4.5 hours. 100 ml of water and 150 ml of dichloromethane were added to the resulting solution, and the organic layer was separated. The extract was washed with 200 ml of saturated brine and dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain 10.3 g of 5-DDT-BPin represented by the following formula.

To a mixed solution of 338 mg of 4,4′-dibromostilbene, 1.10 g of the above 5-DDT-BPin, 36.0 ml of toluene, 7.20 ml of ethanol, and 10.0 ml of 2M aqueous sodium carbonate solution, tetrakis (triphenylphosphine) palladium (0 ) 52.0 mg was added and the mixture was heated and stirred at 100 ° C. for 17.5 hours under a nitrogen atmosphere. 50 ml of water and 100 ml of dichloromethane were added to the resulting solution, and the solid was collected by filtration. After washing with methanol and hexane, recrystallization was performed from 50 ml of toluene. After vacuum drying, 470 mg of a yellow glossy powder was obtained. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (24).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.86-0.90 (t, 6H), 1.27 (m, 36H), 1.68-1.73 (m, 4H), 2 78-2.84 (m, 4H), 6.73-6.74 (d, 2H), 7.08 (s, 2H), 7.12-7.14 (d, 2H), 7.46 -7.56 (dd, 8H).

Synthesis Example 4 (Synthesis of Compound (72))
To a mixed solution of 400 mg of 4-bromostilbene, 2.10 g of 5-DDT-BPin, 70.0 ml of toluene, 15 ml of ethanol, and 20 ml of 2M aqueous sodium carbonate solution, 100 mg of tetrakis (triphenylphosphine) palladium (0) was added, and the atmosphere was nitrogen. And stirred at 100 ° C. for 10 hours. 100 ml of water and 100 ml of dichloromethane were added to the resulting solution, and the solid was collected by filtration. After washing with methanol and hexane, purification was performed by column chromatography (filler: silica gel, eluent: dichloromethane), and after vacuum drying, 810 mg of yellow powder was obtained. The obtained results of ^{1 H-NMR} analysis of the powder are as follows and it was confirmed to be the compound (72).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.86-0.90 (t, 3H), 1.27 (m, 18H), 1.68-1.73 (m, 2H), 2 78-2.84 (m, 2H), 6.73-6.74 (d, 2H), 7.08 (s, 1H), 7.12-7.14 (d, 1H), 7.46 -7.70 (dd, 8H).

Synthesis Example 5 (Synthesis of Compound (36))
3.0 g of 3-n-hexylthiophene was dissolved in 40 ml of tetrahydrofuran and cooled to -80. To this, 12.0 ml of n-butyllithium solution (1.6 mol / l hexane solution) was added dropwise and stirred for 2 hours. The temperature was raised to −20 ° C., 2-isoporopoxy-4,4,5,5-tetramethyl- [1,3,2] dioxaborolane (5.50 g) was added dropwise, and the mixture was stirred at room temperature for 4.5 hours. 100 ml of water and 100 ml of dichloromethane were added to the resulting solution, and the organic layer was separated. The extract was washed with 300 ml of saturated brine and dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain 4.64 g of 4-n-HT-BPin shown below.

  To a mixed solution of 4,4′-dibromostilbene 409 mg, 4-n-HT-BPin thiophene 1.82 g, toluene 50 ml, ethanol 15 ml, 2M aqueous sodium carbonate solution 20 ml, tetrakis (triphenylphosphine) palladium (0) 120 mg was added, The mixture was heated and stirred at 100 ° C. for 19 hours under a nitrogen atmosphere. The resulting solid was collected by filtration, washed with methanol and hexane, and recrystallized from 50 ml of toluene. After vacuum drying, 438 mg of BTS represented by the following formula was obtained.

  BTS (438 mg) was dissolved by heating in chloroform (50 ml), and dimethylformamide (200 ml) was added. 343 mg of n-bromosuccinimide was added here, and it stirred at room temperature under nitrogen atmosphere for 4.5 hours. The precipitated solid was collected by filtration and washed with methanol to obtain 506.5 mg of BTS-2Br represented by the following formula.

To a mixed solution of 87.8 mg of BTS-2Br, 972 mg of 5-DDT-BPin, 10 ml of toluene, 2.0 ml of ethanol and 3.0 ml of 2M aqueous sodium carbonate solution, 30.9 mg of tetrakis (triphenylphosphine) palladium (0) was added. In addition, the mixture was heated and stirred at 100 ° C. for 9 hours under a nitrogen atmosphere. 50 ml of water and 100 ml of dichloromethane were added to the resulting solution, the organic layer was separated, washed with 100 ml of water and then dried over anhydrous sodium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain an orange solid. Recrystallization from toluene gave 48.2 mg of a yellow solid. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (36).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.86-0.90 (m, 48H), 1.27 (m, 36H), 1.62-1.70 (m, 8H), 2 .72-2.84 (m, 8H), 6.72-6.73 (d, 2H), 6.95-6.96 (d, 2H), 7.11-7.16 (d, 4H) 7.49-7.59 (dd, 8H).

Synthesis Example 6 (Synthesis of Compound (74))
300 mg of BTS was dissolved in 35 ml of chloroform with heating, and 150 ml of dimethylformamide was added. To this was added 272 mg of n-bromosuccinimide, and the mixture was stirred at room temperature for 3 hours under a nitrogen atmosphere. The precipitated solid was collected by filtration, washed with methanol, and purified by column chromatography (filler: silica gel, eluent: dichloromethane). After vacuum drying, 420 mg of BTS-Br represented by the following formula was obtained.

To a mixed solution of 170 mg of BTS-Br, 980 mg of 5-DDT-BPin, 20 ml of toluene, 3.0 ml of ethanol, and 4.0 ml of 2M aqueous sodium carbonate solution, 32.9 mg of tetrakis (triphenylphosphine) palladium (0) was added. The mixture was heated and stirred at 100 ° C. for 7 hours in a nitrogen atmosphere. 150 ml of water and 100 ml of dichloromethane were added to the resulting solution to separate the organic layer, washed with 100 ml of water and then dried over anhydrous sodium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator, and the residue was purified by column chromatography (filler: silica gel, eluent: dichloromethane). After vacuum drying, 810 mg of yellow powder was obtained. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (74).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.86-0.90 (t, 6H), 1.27
(M, 22H), 1.62-1.70 (m, 4H), 2.72-2.84 (m, 4H), 6.72-6.73 (d, 2H), 6.95-6 .96 (d, 1H), 7.11-7.16 (d, 2H), 7.49-7.59 (dd, 8H).

Synthesis Example 7 (Synthesis of Compound (37))
17.4 g of 2-thiophene ethanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was cooled to 0 ° C., and a suspension obtained by adding 7.05 g of sodium hydride (60% oily) to 110 ml of tetrahydrofuran was added dropwise. The mixture was stirred at 0 ° C. for 20 minutes in a nitrogen atmosphere, and 27.4 g of 1-bromononane (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise. Thereafter, the temperature was raised to 90 ° C., and the mixture was heated and stirred for 8 hours. 100 ml of water and 100 ml of dichloromethane were added to the reaction solution, and the organic layer was separated. The extract was washed with 300 ml of saturated brine and dried over anhydrous sodium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 19.7 g of nonyloxyethylthiophene.

  11.7 g of nonyloxyethylthiophene was dissolved in 90 ml of tetrahydrofuran and cooled to -80 ° C. To this, 34.0 ml of n-butyllithium solution (1.6 mol / l hexane solution) was added dropwise and stirred for 6 hours. The temperature was raised to −30 ° C., 10.2 g of 2-isoporopoxy-4,4,5,5-tetramethyl- [1,3,2] dioxaborolane was added dropwise, and the mixture was stirred at room temperature for 18 hours. 100 ml of water and 100 ml of hexane were added to the resulting solution, and the organic layer was separated. After washing with 300 ml of water, it was dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain 8.75 g of 5-NOET-BPin represented by the following formula.

To a mixed solution of 207 mg of 4,4′-dibromostilbene, 685 mg of 5-NOET-BPin, 20 ml of toluene, 4 ml of ethanol, and 5 ml of 2M aqueous sodium carbonate solution, 67.0 mg of tetrakis (triphenylphosphine) palladium (0) was added, and a nitrogen atmosphere Under stirring at 100 ° C. for 10 hours. 70 ml of dichloromethane and 50 ml of water were added to the resulting solution to separate the organic layer. After washing with 150 ml of water, it was dried over anhydrous magnesium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 79.6 mg of a light yellow powder. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (37).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.85-0.90 (m, 6H), 1.27 (m, 24H), 1.57-1.63 (m, 4H), 3 .07-3.12 (t, 4H), 3.45-3.50 (t, 4H), 3.66-3.70 (t, 4H), 6.81-6.82 (d, 2H) 7.10 (s, 2H), 7.15-7.17 (d, 2H), 7.48-7.57 (dd, 8H).

Synthesis Example 8 (Synthesis of Compound (76))
To a mixed solution of 400 mg of 4-dibromostilbene, 690 mg of the above-mentioned 5-NOET-BPin, 25 ml of toluene, 6 ml of ethanol, and 7 ml of 2M aqueous sodium carbonate solution, 75.0 mg of tetrakis (triphenylphosphine) palladium (0) was added. The mixture was heated and stirred at 0 ° C. for 8 hours. To the resulting solution, 100 ml of dichloromethane and 150 ml of water were added, and the organic layer was separated. After washing with 150 ml of water, it was dried over anhydrous magnesium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 82.1 mg of a light yellow powder. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (76).
_{^{1 H-NMR (CDCl 3 (}} d = ppm)): 0.85-0.90 (m, 3H), 1.27 (m, 12H), 1.57-1.63 (m, 2H), 3 .07-3.12 (t, 2H), 3.45-3.50 (t, 2H), 3.66-3.70 (t, 2H), 6.81-6.82 (d, 2H) 7.10 (s, 1H), 7.15-7.17 (d, 1H), 7.48-7.57 (dd, 8H).

Synthesis Example 9 (Synthesis of Compound (60))
18.0 g of 2-thiophene ethanol is cooled to 0 ° C. and sodium hydride (60% oily)
A suspension obtained by adding 7.15 g to 110 ml of tetrahydrofuran was added dropwise. The mixture was stirred at 0 ° C. for 20 minutes in a nitrogen atmosphere, and 28.1 g of 1- (2-bromoethoxy) -butane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise. Thereafter, the temperature was raised to 90 ° C., and the mixture was heated and stirred for 9 hours. 100 ml of water and 100 ml of dichloromethane were added to the reaction solution, and the organic layer was separated. After washing with 200 ml of water, it was dried over anhydrous sodium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 21.5 g of 2- (2- (butyloxy) ethyloxy) ethylthiophene.

  13.4 g of 2- (2- (butyloxy) ethyloxy) ethylthiophene was dissolved in 100 ml of tetrahydrofuran and cooled to -80 ° C. Here, 40.0 ml of n-butyllithium solution (1.6 mol / l hexane solution) was added dropwise and stirred for 5 hours. The temperature was raised to -30 ° C, and 13.2 g of 2-isoporopoxy-4,4,5,5-tetramethyl- [1,3,2] dioxaborolane was added dropwise, followed by stirring at room temperature for 20 hours. 100 ml of water and 100 ml of hexane were added to the resulting solution, and the organic layer was separated. After washing with 300 ml of water, it was dried over anhydrous magnesium sulfate. From the obtained solution, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain 9.12 g of 5-BOEOET-BPin represented by the following formula.

To a mixed solution of 4,4′-dibromostilbene 0.50 mg, the above-mentioned 5-BOEOET-BPin 1.53 g, toluene 60 ml, ethanol 20 ml, and 2M aqueous sodium carbonate solution 25 ml, tetrakis (triphenylphosphine) palladium (0) 210 mg was added, The mixture was heated and stirred at 100 ° C. for 13 hours in a nitrogen atmosphere. To the obtained solution, 150 ml of dichloromethane and 200 ml of water were added, and the organic layer was separated. After washing with 300 ml of water, it was dried over anhydrous magnesium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 237 mg of a yellow powder. The obtained results of ^{1 H-NMR} analysis of the powder are as follows and it was confirmed to be the compound (60).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.89-0.94 (t, 6H), 1.32-1.41 (m, 4H), 1.54-1.60 (t, 4H), 3.09-3.14 (t, 4H), 3.44-3.49 (t, 4H9, 3.57-3.64 (m, 8H), 3.69-3.74 (t , 4H), 6.83-6.84 (d, 2H), 7.08 (s, 2H), 7.15-7.16 (d, 2H), 7.48-7.55 (dd, 8H) )

Synthesis Example 10 (Synthesis of Compound (80))
To a mixed solution of 1.13 g of 4-bromostilbene, 1.92 g of 5-BOEOET-BPin, 100 ml of toluene, 30 ml of ethanol, and 40 ml of 2M aqueous sodium carbonate solution, 410 mg of tetrakis (triphenylphosphine) palladium (0) was added, and under nitrogen atmosphere The mixture was heated and stirred at 100 ° C. for 10 hours. To the obtained solution, 150 ml of dichloromethane and 200 ml of water were added, and the organic layer was separated. After washing with 500 ml of water, it was dried over anhydrous magnesium sulfate. The resulting solution was concentrated by a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 500 mg of a light yellow powder. The results of 1H-NMR analysis of the obtained powder are as follows, and it was confirmed that the powder was 80.
¹ H-NMR (CDCl ₃ (d = ppm)): 0.89-0.94 (t, 3H), 1.32-1.41 (m, 2H), 1.54-1.60 (t, 2H), 3.09-3.14 (t, 2H), 3.44-3.49 (t, 2H), 3.57-3.64 (m, 4H), 3.69-3.74 ( t, 2H), 6.83-6.84 (d, 2H), 7.08 (s, 1H), 7.15-7.16 (d, 1H), 7.48-7.55 (dd, 8H).

Synthesis Example 11 (Synthesis of Compound (62))
A mixed solution of 3.1 g of 4,4′-bis (chloromethyl) biphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.) and 8.6 ml of triethyl phosphite was heated and stirred at 150 ° C. for 5 hours. After cooling to room temperature, 50 ml of dimethyl sulfoxide and 2.8 g of potassium tert-butoxide were added and stirred at room temperature for 10 minutes. Subsequently, 4.9 g of 3-hexyl-2-thiophene aldehyde (manufactured by Aldrich) was added and stirred at room temperature for 5 hours. 30 ml of ethanol was added to the resulting solution, filtered, and washed with 20 ml of ethanol to obtain 2.8 g of TPV represented by the following formula.

  1.78 g of N-bromosuccinimide was added to a mixed solvent of 2.8 g of the above TPV and 30 ml of dimethylformamide, and stirred at room temperature for 10 hours under a nitrogen stream. The obtained solution was filtered and washed with 10 ml of dimethylformamide and 20 ml of methanol to obtain 1.4 g of TPV-2Br represented by the following formula.

To a mixed solution of 0.53 g of the above 4T-BPin, 0.20 g of the above TPV-2Br and 15 ml of toluene, add 3 ml of ethanol, 5 ml of 2N sodium carbonate aqueous solution and 10 mg of tetrakis (triphenylphosphine) palladium (0), and add nitrogen. The mixture was refluxed at 110 ° C. for 6 hours under an air stream. 20 ml of water and 50 ml of dichloromethane were added to the resulting solution to separate the organic layer. After washing with 20 ml of water, it was dried over magnesium sulfate. The resulting solution was concentrated with a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) and vacuum-dried to obtain 70 mg of a red-orange powder. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (62).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.87-0.94 (t, 18H), 1.28-1.36 (m, 36H), 1.60-1.68 (m, 12H), 2.65-2.81 (m, 12H), 6.91-6.95 (m, 6H), 7.02-7.05 (m, 6H), 7.13 (d, 4H) 7.18 (d, 2H), 7.26 (d, 2H), 7.53-7.64 (dd, 8H).

Synthesis Example 12 (Synthesis of Compound (82))
To a mixed solvent of 2.5 g of the above TPV and 20 ml of dimethylformamide, 0.85 g of N-bromosuccinimide was added and stirred at room temperature for 5 hours under a nitrogen stream. The obtained solution was filtered and purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) to obtain 0.90 g of TPV-Br represented by the following formula.

To a mixed solution of 0.53 g of 4T-BPin, 0.50 g of the above TPV-Br and 20 ml of toluene, 5 ml of ethanol, 10 ml of 2N sodium carbonate aqueous solution and 25 mg of tetrakis (triphenylphosphine) palladium (0) were added, and a nitrogen stream was added. The mixture was refluxed at 110 ° C. for 6 hours. 50 ml of water and 50 ml of dichloromethane were added to the resulting solution to separate the organic layer. After washing with 50 ml of water, it was dried over magnesium sulfate. The resulting solution was concentrated with a rotary evaporator and then purified by column chromatography (filler: silica gel, eluent: hexane / dichloromethane) and vacuum dried to obtain 70 mg of orange powder. The results of ¹ H-NMR analysis of the obtained powder are as follows and it was confirmed that this powder was compound (82).
¹ H-NMR (CDCl ₃ (d = ppm)): 0.87-0.94 (t, 12H), 1.28-1.36 (m, 24H), 1.60-1.68 (m, 8H), 2.65-2.81 (m, 8H), 6.91-6.95 (m, 4H), 7.02-7.05 (m, 2H), 7.13 (d, 4H) 7.18 (d, 2H), 7.26 (d, 2H), 7.53-7.64 (dd, 8H).

Example 1
(1) Preparation of organic semiconductor composite solution Poly-3-hexylthiophene (residual, number-average molecular weight (Mn): 13,000, hereinafter referred to as P3HT), which is a conjugated polymer, is contained in 5 ml of chloroform. In addition to the flask, a P3HT chloroform solution was obtained by ultrasonically stirring in an ultrasonic cleaner (US-2 manufactured by Iuchi Seieido Co., Ltd., output 120 W). Subsequently, this solution was taken in a dropper, and 0.5 ml was dropped into a mixed solution of 20 ml of methanol and 10 ml of 0.1N hydrochloric acid to perform reprecipitation. The solid P3HT was collected by filtration with a 0.1 μm pore size membrane filter (PTFE: tetrafluoroethylene), rinsed well with methanol, and then the solvent was removed by vacuum drying. Further, dissolution and reprecipitation were performed again to obtain 90 mg of reprecipitation P3HT.

  Next, 1.5 mg of CNT (manufactured by CNI, single-walled CNT, purity 95%, hereinafter referred to as single-walled CNT) and 1.5 mg of the above P3HT are added to 30 ml of chloroform, and an ultrasonic homogenizer (Tokyo Rika Co., Ltd.) is cooled with ice. Using an instrument (VCX-500 manufactured by Kikai Co., Ltd.), the mixture was ultrasonically stirred at an output of 250 W for 30 minutes. When the ultrasonic irradiation was performed for 30 minutes, the irradiation was stopped once, 1.5 mg of P3HT was added, and ultrasonic irradiation was further performed for 1 minute, whereby the CNT composite dispersion A (CNT concentration 0.05 g / l with respect to the solvent) was obtained. )

  In order to investigate whether or not P3HT was adhered to the CNT in the CNT composite dispersion A, 5 ml of the dispersion A was filtered using a membrane filter, and CNT was collected on the filter. The collected CNTs were quickly transferred onto a silicon wafer before the solvent was dried to obtain dried CNTs. When this CNT was subjected to elemental analysis using X-ray photoelectron spectroscopy (XPS), sulfur element contained in P3HT was detected. Therefore, it was confirmed that P3HT was adhered to the CNT in the CNT composite dispersion A.

  Next, an organic semiconductor composite solution for forming the semiconductor layer 4 was prepared. The dispersion A was filtered using a membrane filter (pore size: 10 μm, diameter: 25 mm, Omnipore membrane manufactured by Millipore) to remove CNTs having a length of 10 μm or more. The obtained filtrate was designated as CNT composite dispersion B. 4 mg of compound (1) as organic semiconductor (A) and 1 mg of compound (69) as organic semiconductor (B) are added to a mixed solution of 0.2 ml of CNT complex dispersion B and 0.8 ml of tetrahydronaphthalene to prepare an organic semiconductor composite solution. did. At this time, the organic semiconductor (B) is 25 parts by weight with respect to 100 parts by weight of the organic semiconductor (A), the concentration of the whole organic semiconductor in the organic semiconductor composite solution is 5 g / l, and the concentration of CNT with respect to the organic semiconductor is 0. Adjusted to 2 wt%.

(2) Preparation of polymer solution for insulating layer 61.29 g (0.45 mol) of methyltrimethoxysilane, 12.31 g (0.05 mol) of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and phenyl 99.15 g (0.5 mol) of trimethoxysilane was dissolved in 203.36 g of propylene glycol monomethyl ether acetate (boiling point 170 ° C.), and 54.90 g of water and 0.864 g of phosphoric acid were added thereto with stirring. The obtained solution was heated at a bath temperature of 105 ° C. for 2 hours, the internal temperature was raised to 90 ° C., and a component mainly composed of methanol produced as a by-product was distilled off. Subsequently, the bath temperature is heated at 130 ° C. for 2.0 hours, the internal temperature is raised to 118 ° C., the components mainly composed of water are distilled off, and then cooled to room temperature to obtain a polymer solution having a solid content concentration of 26.0% by weight. A was obtained.

  50 g of the obtained polymer solution A was weighed, 16.6 g of propylene glycol monomethyl ether acetate was mixed, and the mixture was stirred at room temperature for 2 hours to obtain a polymer solution B (solid content concentration 19.5 wt%).

(3) Production of Organic FET The organic FET shown in FIG. 1 was produced. A gate electrode 2 was formed on a glass substrate 1 by vacuum evaporation of 5 nm of chromium and 50 nm of gold through a mask by a resistance heating method. Next, the polymer solution B prepared by the method described in (2) above is spin-coated (2000 rpm × 30 seconds) on the glass substrate on which the gate electrode is formed, and heat-treated at 200 ° C. for 1 hour in a nitrogen stream. Thus, the gate insulating layer 3 having a thickness of 600 nm was formed. Next, gold was vacuum-deposited so as to have a film thickness of 50 nm through a mask by a resistance heating method, and the source electrode 5 and the drain electrode 6 were formed.

  The width (channel width) of these two electrodes was 0.1 cm, and the distance (channel length) between both electrodes was 20 μm. 0.1 μL of the organic semiconductor composite solution prepared by the method described in (1) above is dropped on the substrate on which the electrode is formed, and air-dried at 30 ° C. for 10 minutes, and then on a hot plate at 150 ° C. under a nitrogen stream. A heat treatment was performed for 30 minutes to obtain an organic FET. Similarly, 30 organic FETs were produced.

Next, the source-drain current (Id) -source-drain voltage (Vsd) characteristics when the gate voltage (Vg) of the organic FET was changed were measured. The measurement was performed in the atmosphere using a semiconductor characteristic evaluation system 4200-SCS type (manufactured by Keithley Instruments Co., Ltd.). When the mobility in the linear region was determined from the change in the value of Id at Vsd = −5V when Vg = + 30 to −30V, the average mobility of the 30 organic FETs was 0.38 cm ² / V.・ It was sec. Further, when the on / off ratio was determined from the ratio between the maximum value and the minimum value of Id at this time, the average was 5.5 × 10 ⁵ . At this time, the standard deviation of the logarithmic value of the mobility was found to be σ = 0.33, and the standard deviation of the logarithmic value of the on / off ratio was σ = 0.29.

Comparative Example 1
An FET element was formed in the same manner as in Example 1 except that only the compound (1) was used as the organic semiconductor, and the characteristics were measured. When the mobility of the linear region was obtained from the change in the value of Id at Vsd = −5 V when Vg = + 50 to −50 V, the average mobility was 0.42 cm ² / V · sec. When the on / off ratio was determined from the ratio between the maximum value and the minimum value of Id, the average value was 7.8 × 10 ⁴ . At this time, the standard deviation of the logarithmic value of the mobility was 0.48, and the standard deviation of the on / off ratio was 0.85.

Examples 2-6, Comparative Examples 2-8
An organic FET was formed in the same manner as in Example 1 except that the organic semiconductor shown in Table 1 was used as the organic semiconductor, and the characteristics were measured. The results of each example and comparative example are shown in Table 1.

  The organic semiconductor composite of the present invention is used for organic TFTs that can be used in transistor arrays for smart cards, security tags, flat panel displays, and other organic transistors.

1 Substrate 2 Gate electrode 3 Insulating layer
4 Semiconductor layer 5 Source electrode 6 Drain electrode

Claims (6)

An organic semiconductor composite comprising a carbon nanotube and a plurality of organic semiconductors having a molecular weight of 3000 or less, wherein the plurality of organic semiconductors having a molecular weight of 3000 or less are at least an organic semiconductor (A) having a molecular weight M (A) and the organic semiconductor (A An organic semiconductor composite containing an organic semiconductor (B) having a molecular weight M (B) and having a partial structure of 2) (M) and M (B) satisfying a relationship of 2M (B) ≧ M (A). The organic semiconductor composite according to claim 1, wherein the organic semiconductor (A) is represented by the following general formula (1).

(In the general formula (1), X ¹ represents a divalent linking group consisting of a single bond, vinylene group, ethynylene group, azo group, azomethine group, ether group, arylene group, heteroarylene group, or a combination thereof. Y ¹ and Y ² may be the same or different and each represents a group represented by the following general formula (2).

(In the general formula (2), R ¹ ~R ⁵ may be the same or different and are each hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group , Alkylthio group, aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen atom, cyano group, formyl group, carbamoyl group, amino group, alkylcarbonyl group, arylcarbonyl group, carboxyl group, alkoxycarbonyl group, aryl An oxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, or a silyl group, and adjacent R ^{1 to} R ² or R ^{3 to} R ⁵ may be bonded to each other to form a ring structure. Represents an integer of 0 to 10.) The organic semiconductor composite according to claim 2, wherein the organic semiconductor (B) is represented by the following general formula (3).

(In the general formula (3), X ¹ represents a divalent linking group consisting of a single bond, vinylene group, ethynylene group, azo group, azomethine group, ether group, arylene group, heteroarylene group, or a combination thereof. Y ¹ represents a group represented by the general formula (2).) The organic semiconductor composite according to any one of claims 1 to 3, wherein the carbon nanotube has a conjugated polymer attached to at least a part of its surface. Content of the said organic semiconductor (B) is 100 weight part or less with respect to 100 weight part of said organic semiconductor (A), The organic-semiconductor composite in any one of Claims 1-4. An organic field effect transistor having a gate electrode, an insulating layer, a semiconductor layer, a source electrode and a drain electrode, wherein the semiconductor layer contains the organic semiconductor composite according to any one of claims 1 to 5.

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