JP2010034394A - Organic thin film transistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic thin film transistor (organic TFT) that achieves not only excellent stability in field effect mobility but also high response speed even after being stored at high temperature. <P>SOLUTION: In the organic thin film transistor, at least three terminals comprised of a gate electrode, a source electrode and drain electrode, and an insulator layer and organic semiconductor layer are disposed on a substrate, and current between a source and drain is controlled by applying voltage to the gate electrode. The organic thin film transistor includes a channel control layer with the film thickness of 1-100 nm disposed between the insulator layer and organic semiconductor layer. The channel control layer contains an amorphus organic compound whose ionization potential is less than 5.8 eV and molecular weight is 1,000 or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic thin film transistor, and more particularly to an organic thin film field effect transistor having excellent field effect mobility stability and high response speed even when stored at high temperatures.

Thin film transistors (hereinafter sometimes abbreviated as TFTs) are widely used as display switching elements in liquid crystal display devices and the like. A cross-sectional structure of a typical TFT is shown in FIG. As shown in FIG. 1, a TFT has a gate electrode, an insulator layer, and an organic semiconductor layer in this order on a substrate, and has a source electrode and a drain electrode formed on the organic semiconductor layer at a predetermined interval. Have. A part of the source electrode and the drain electrode is exposed on the surface, and a semiconductor layer is formed on the surface exposed between the electrodes. In the TFT having such a structure, the semiconductor layer forms a channel region, and the current flowing between the source electrode and the drain electrode is controlled by the voltage applied to the gate electrode, and the on / off operation is performed.
Conventionally, TFTs have been manufactured using amorphous or polycrystalline silicon. However, CVD devices used for manufacturing TFTs using such silicon are expensive and large-sized display devices using TFTs or the like. There has been a problem that the production is accompanied by a significant increase in manufacturing cost. In addition, the process of depositing amorphous or polycrystalline silicon is performed at a very high temperature, so the types of materials that can be used as a substrate are limited, light weight and flexibility can be imparted. However, there is a problem that a resin substrate or the like that can be designed in shape cannot be used. If a TFT can be manufactured on a lightweight resin substrate, it is expected that it can be applied to a portable electronic device.

  In order to solve such a problem, a TFT using an organic semiconductor (hereinafter sometimes abbreviated as an organic TFT) has been proposed. Vacuum deposition and coating methods are known as film formation methods used when forming TFTs with organic semiconductors. According to these film formation methods, the device can be enlarged while suppressing an increase in manufacturing cost. Therefore, the process temperature required for film formation can be made relatively low. In addition, TFTs using organic substances have the advantage that there are few restrictions when selecting materials used for the substrate, and their practical application is expected. Under such circumstances, many research reports on organic TFTs have been issued. For example, non-patent documents 1 to 3 can be cited. As a material used for a semiconductor layer of a TFT, a p-type polymer such as a conjugated polymer or thiophene (Patent Document 1), a condensed aromatic hydrocarbon such as pentacene (Patent Document 2), or the like is known. . In addition, n-type FET materials include 1,4,5,8-naphthalenetetracarboxyldianhydride (NTCDA), 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TCNNQD), 1 , 4,5,8-naphthalenetetracarboxyldiimide (NTCDI) and the like are disclosed in Patent Document 3.

An organic electroluminescence element (hereinafter sometimes abbreviated as an organic EL element) is known as a device that uses electrical conduction in the same manner as an organic TFT. The organic EL element generally applies a strong electric field of 10 ⁵ V / cm or more in the film thickness direction to an ultra-thin film of 100 nm or less, and forcibly flows charges, whereas in the case of an organic TFT, it is several μm. It is necessary to flow charges at high speed with an electric field of 10 ⁵ V / cm or less over the above distance. For this reason, the organic substance itself needs to have conductivity higher than that of the organic EL element material. However, the organic substance used in the conventional organic TFT has a small field effect mobility (hereinafter, sometimes abbreviated as mobility) and a slow response speed. For this reason, there was a problem in high-speed response as a transistor. Also, the on / off ratio was small.
Here, the on / off ratio means that when a gate voltage is applied, that is, the current flowing between the source and the drain in the on state (on current), when the gate voltage is not applied, that is, in the off state. Divided by the current flowing between the source and drain. The on-current is a current value (saturation current) when the current flowing between the source and the drain is saturated when the gate voltage is increased.
Attempts have been made to solve such problems of organic TFTs and improve mobility by improving the element configuration. For example, a deposited film of N, N′-dinaphthalen-1-yl-N, N′-diphenyl-biphenyl-4,4′-diamine (NPD) is inserted at the interface between the channel layer (organic semiconductor layer) and the insulating layer. Attempts have been made (Non-Patent Document 4). However, since NPD has a low glass transition temperature and lacks heat resistance, there has been a problem that when it is put to practical use at high temperatures, the mobility decreases with time. On the other hand, in order to obtain a heat-stable organic TFT, attempts have been made to crosslink and use a polymer such as polystyrene (Non-Patent Document 5), but this alone has a problem that high mobility cannot be obtained. there were.

JP-A-8-228034 JP-A-5-55568 Japanese Patent Laid-Open No. 10-135481 Horowitz et al. Advanced Materials, Vol. 8, No. 3, 242, 1996 H. Fuchigami et al., Applied Physics Letter, 63, 1372, 1993 Lay-Lay Chua et al., Nature, 434, March 10, 2005, p.194 Ishikawa et al., Proceedings of the 54th Joint Applied Physics Conference in Spring 2007, 30a-W-11, p. 1424 Myung-Han Yoon et al., J. AM. CHEM. SOC. 2005, 127, 10388-10395

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an organic thin film transistor that has excellent field effect mobility stability and high response speed even when stored at high temperatures.

As a result of intensive studies to achieve the above object, the present inventors have found that an amorphous material having a specific ionization potential and molecular weight is formed between an insulator layer and an organic semiconductor layer constituting an organic thin film transistor. It has been found that the response speed (driving speed) can be increased by forming the channel control layer to be contained, and that it is stable against storage under high temperature conditions, and the present invention has been completed.
That is, in the present invention, at least three terminals of a gate electrode, a source electrode, and a drain electrode, an insulator layer, and an organic semiconductor layer are provided on a substrate, and a source-drain current is controlled by applying a voltage to the gate electrode. An organic thin film transistor having a channel control layer having a thickness of 1 to 100 nm between the insulator layer and the organic semiconductor layer, the channel control layer having an ionization potential of less than 5.8 eV An organic thin film transistor comprising an amorphous organic compound having a molecular weight of 1000 or more is provided.

    The organic thin film transistor of the present invention has a high response speed (driving speed) and is excellent in stability of field effect mobility even when stored at high temperature.

  The present invention provides an organic thin film transistor in which at least three terminals of a gate electrode, a source electrode, and a drain electrode, an insulator layer, and an organic semiconductor layer are provided on a substrate, and a source-drain current is controlled by applying a voltage to the gate electrode. (Hereinafter, it may be abbreviated as an organic TFT.) And having a channel control layer having a film thickness of 1 to 100 nm, preferably 1 to 50 nm, between the insulator layer and the organic semiconductor layer. The channel control layer is an organic thin film transistor containing an amorphous organic compound having an ionization potential of less than 5.8 eV and a molecular weight of 1000 or more. Here, the molecular weight indicates a weight average molecular weight when an amorphous organic compound having an ionization potential of less than 5.8 eV contained in the channel control layer is a compound having a repeating unit, and is a single compound other than that. In this case, a normal molecular weight (relative mass obtained on the basis of the mass of oxygen molecule as 32) is shown.

Hereinafter, the details of the organic TFT of the present invention will be described.
(Basic element configuration)
As an element configuration of the organic TFT of the present invention, at least three terminals of a gate electrode, a source electrode and a drain electrode, an insulator layer and an organic semiconductor layer are provided on a substrate, and between the organic semiconductor layer and the insulator layer. The TFT is not limited as long as the channel control layer is inserted and the source-drain current is controlled by applying a voltage to the gate electrode. It may be based on a known element configuration. The present invention is characterized in that a channel control layer containing a specific amorphous organic material is inserted between the organic semiconductor layer and the insulator layer.
The element configurations A to D of the present invention are illustrated in FIGS. The element configuration of the organic TFT is not limited to the element configurations A to D. As shown in the element configurations A to D, some known basic configurations are known depending on the position of the electrodes, the stacking order of the layers, and the like, but the organic TFT of the present invention is a field effect transistor (FET: Field Effect Transistor). ) Having a structure. The organic TFT is formed with an organic semiconductor layer, an insulator layer, a source electrode and a drain electrode formed so as to face each other with a predetermined distance, and a predetermined distance from the source electrode and the drain electrode. A current flowing between the source and drain electrodes by applying a voltage to the gate electrode. Here, the distance between the source electrode and the drain electrode is usually determined depending on the application, and is usually 0.1 μm to 1 mm, preferably 1 μm to 1 mm, more preferably 1 μm to 100 μm, and further preferably 5 μm to 100 μm.

  Of the elements A to D, the element C shown in FIG. 4 will be described in more detail as an example. The element C has a gate electrode, an insulator layer, a channel control layer, and an organic semiconductor layer in this order on a substrate, and a pair of source and drain electrodes formed on the organic semiconductor layer at a predetermined interval. have. The current applied between the source electrode and the drain electrode is controlled by the voltage applied to the gate electrode, and the on / off operation is performed.

(Function of channel control layer)
The channel control layer has a function of improving mobility by reducing carrier traps at the interface with the organic semiconductor layer formed thereon. Further, the stability of the organic TFT in the air is improved by reducing the carrier trap.

(Physical characteristics of the amorphous organic compound contained in the channel control layer)
The channel control layer includes an amorphous organic compound having an ionization potential (Ip) of less than 5.8 eV, preferably 5.7 eV or less, more preferably 5.5 eV or less. If the Ip of the amorphous organic compound contained in the channel control layer is 5.8 eV or more, carrier traps are generated, and the mobility becomes insufficient. The lower limit value of Ip is not particularly limited, but is preferably 4.0 eV or more from the viewpoint of availability of materials.
As the amorphous organic compound, those having a molecular weight of 1000 or more are used. For example, since a portable electronic device may be placed in a high temperature environment of 100 ° C. or higher, high temperature storage properties described later are required. Therefore, by using an amorphous organic compound having a molecular weight of 1000 or more for the channel control layer, high-temperature storage at 100 ° C., which is essential for portable electronic devices, can be achieved. Thereby, the performance fall in a high temperature environment can be suppressed. In addition, when a channel control layer is formed using an amorphous organic compound having a molecular weight of 1000 or more, resistance to an organic solvent is manifested, so that an organic semiconductor layer or an insulator layer can be laminated thereon by coating. Become. Even when a coating method from a solution is used, the channel control layer is not completely dissolved by the solvent, and the mobility improvement effect of the channel control layer is not impaired. Thus, the molecular weight greatly contributes to the stability of the film. The molecular weight of the amorphous organic compound is more preferably 10,000 or more, and particularly preferably 100,000 or more. The upper limit is not particularly limited, but is usually 10,000,000 or less.
Furthermore, the amorphous organic compound is essentially amorphous. By being amorphous, the channel region at the interface with the organic semiconductor layer composed of a single crystal or a polycrystalline substance is usually smooth, and carrier mobility is improved. In addition, the difficulty of forming pinholes and defective portions also contributes to the improvement of mobility. The channel control layer does not need to be completely amorphous, and may include a crystallized portion as long as the effects of the present invention are not impaired.
The channel control layer preferably contains 40 to 100% by mass of the amorphous organic compound, and more preferably 60 to 100%.
By using an amorphous organic compound that satisfies the conditions of the ionization potential and molecular weight for the channel control layer, a channel control layer made of an amorphous material can be formed. The formation of this layer reduces the number of carriers trapped in the channel region and can improve the mobility, so it is named a channel control layer.

(Specific examples of amorphous organic compounds)
The amorphous organic compound is not particularly limited as long as it satisfies the physical properties described above, but specific examples include the amorphous organic compounds exemplified below. By using such an amorphous organic compound for the channel control layer, high mobility and excellent stability under high temperature conditions can be obtained. In this case, a crystalline compound may be added as long as the effects of the present invention are not impaired.
Preferred examples of the amorphous compound used for the channel control layer are listed below, but are not limited thereto.
Preferred as the amorphous compound for use in the channel control layer are amino group-containing organic compounds and hydrocarbon compounds having a condensed aromatic ring. As the amino group-containing organic compound, an aromatic amine compound is preferable in order to achieve 5.8 eV or less. In general, an aromatic amine compound is known as a compound having a small ionization potential (Ip) and is used as a hole transport material for organic EL. Of the aromatic amine compounds, compounds having an aromatic group having condensed aromatic residues such as naphthalene, anthracene, phenanthrene, and chrysene, biphenyl residues, and spiro bonds are preferable. Typical examples of these are shown below.

（式中、Ａｒ¹〜Ａｒ⁶は、それぞれ独立に、置換もしくは無置換の核炭素数６〜４０のアリール基又は置換もしくは無置換の核炭素数３〜４０のヘテロアリール基であり、Ａｒ¹とＡｒ²及びＡｒ⁵とＡｒ⁶は、それぞれ独立に、単結合で連結してカルバゾリル基を形成してもよく、
Ｒ¹〜Ｒ⁴は、それぞれ独立に、ハロゲン原子、カルボキシル基、アミノ基、水酸基、置換もしくは無置換の炭素数１〜４０のアルキル基、置換もしくは無置換の炭素数２〜４０のアルケニル基、置換もしくは無置換の炭素数２〜４０のアルキニル基、又は置換もしくは無置換の炭素数１〜４０のアルコキシ基であり、
ｎ、ｍ、ｐ、及びｑは、それぞれ独立に、０〜４の整数であり、
Ｌは、下記一般式（Ｂ）又は（Ｃ）で表される２価の連結基である。）
−（Ａｒ⁷）_a−（Ａｒ⁸）_b−（Ａｒ⁹）_c− （Ｂ）
（式中、Ａｒ₇〜Ａｒ₉は、それぞれ独立に、置換もしくは無置換の核炭素数６〜４０の２価のアリール基又は置換もしくは無置換の核炭素数３〜４０の２価のヘテロアリール基であり、
ａ、ｂ及びｃは、それぞれ独立に、１〜３の整数である。）

（式中、Ｒ⁵及びＲ⁶は、それぞれ独立に、ハロゲン原子、カルボキシル基、アミノ基、水酸基、置換もしくは無置換の炭素数１〜４０のアルキル基、置換もしくは無置換の炭素数２〜４０のアルケニル基、置換もしくは無置換の炭素数２〜４０のアルキニル基、又は置換もしくは無置換の炭素数１〜４０のアルコキシ基であり、
Ｒ⁵とＲ⁶は、互いに連結して環構造を形成してもよい。） As said amorphous compound, what is represented by the following general formula (A) can be used.

(In the formula, Ar ^{1 to} Ar ⁶ are each independently a substituted or unsubstituted aryl group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted heteroaryl group having 3 to 40 nuclear carbon atoms; Ar ¹ And Ar ² and Ar ⁵ and Ar ⁶ may each independently be linked by a single bond to form a carbazolyl group,
R ^{1 to} R ⁴ are each independently a halogen atom, a carboxyl group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 40 carbon atoms, A substituted or unsubstituted alkynyl group having 2 to 40 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 40 carbon atoms,
n, m, p, and q are each independently an integer of 0 to 4,
L is a divalent linking group represented by the following general formula (B) or (C). )
_{^{- (Ar 7) a - (}} Ar 8) b - (Ar 9) c - (B)
(In the formula, Ar _{7 to} Ar ₉ are each independently a substituted or unsubstituted divalent aryl group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted divalent heteroaryl having 3 to 40 nuclear carbon atoms. Group,
a, b, and c are each independently an integer of 1 to 3; )

Wherein R ⁵ and R ⁶ are each independently a halogen atom, a carboxyl group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted carbon number 2 to 40 An alkenyl group, a substituted or unsubstituted alkynyl group having 2 to 40 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 40 carbon atoms,
R ⁵ and R ⁶ may be linked to each other to form a ring structure. )

Specific examples of the aryl group having 6 to 40 nuclear carbon atoms in the general formula (A) include benzene, naphthalene, anthracene, tetracene, pentacene, phenanthrene, chrysene, triphenylene, corannulene, coronene, hexabenzotriphenylene, hexabenzocoronene, Examples thereof include those having sumanen as a substituent. Specific examples of the heteroaryl group having 3 to 40 nuclear carbon atoms include pyridine, pyrazine, quinoline, naphthyridine, quinoxaline, phenazine, diazaanthracene, pyridoquinoline, pyrimidoquinazoline, pyrazinoquinoxaline, phenanthroline, carbazole, 6, 12-dihydro-6,12-diazaindenofluorene, dibenzothiophene, dithiaindacene, dithiaindenoindene, thienothiophene, dithienothiophene, dibenzofuran, benzodifuran, dibenzoselenophene, diselenaindacene, diselenaindenoindene , Dibenzosilol and the like.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Specific examples of the alkyl group having 1 to 40 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, An n-hexyl group, an n-heptyl group, an n-octyl group, etc. are mentioned.
The alkenyl group having 2 to 40 carbon atoms includes both linear and branched alkenyl groups, and those having 2 to 15 carbon atoms are preferable.
The alkynyl group having 2 to 40 carbon atoms includes both linear and branched alkynyl groups, and those having 2 to 15 carbon atoms are preferable.
The alkoxy group is a group represented by —OX ¹ , and specific examples of X ¹ include the same examples as those described for the alkyl group.
Specific examples of the ring structure include cycloalkanes having 4 to 12 carbon atoms such as cycloalkanes having 4 to 12 carbon atoms such as cyclobutane, cyclopentane, cyclohexane, adamantane and norbornane, cyclobutenes, cyclopentene, cyclohexene, cycloheptene and cyclooctene. C6-C12 cycloalkadiene, such as cyclohexadiene, cycloheptadiene, cyclooctadiene, benzene, naphthalene, phenanthrene, anthracene, pyrene, chrysene, acenaphthylene, etc., aromatic ring, pyrrolidine, Examples include heterocyclic rings such as piperidine.

Specific examples of the amorphous organic compound represented by the general formula (A) include the following compounds.

The amorphous organic compound is not limited to those represented by the general formula (A), and may be an oligomer having an amino group having a molecular weight of 1000 or more, and examples thereof include the following compounds.

（式中、Ｒ⁷〜Ｒ¹³は、それぞれ独立に、水素原子、ハロゲン原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルケニル基、炭素数１〜２０のアルキニル基、炭素数１〜２０のハロアルキル基、炭素数１〜３０のアルコキシル基又は炭素数１〜２０のカルボニル基を有する基であり、またＲ⁹〜Ｒ¹³のうち隣接するもの同士で飽和又は不飽和の環状構造を形成していても良く、
ｄは１又は２である。） The amorphous organic compound is preferably an amino group-containing polymer compound having a repeating unit represented by the following general formula (D) or (E).

(In formula, R < ⁷ > -R < ¹³ > is respectively independently a hydrogen atom, a halogen atom, a C1-C20 alkyl group, a C1-C20 alkenyl group, a C1-C20 alkynyl group, carbon number. A group having 1 to 20 haloalkyl groups, an alkoxyl group having 1 to 30 carbon atoms, or a carbonyl group having 1 to 20 carbon atoms, and a saturated or unsaturated cyclic structure between adjacent ones of R ^{9 to} R ¹³ May form,
d is 1 or 2. )

（式中、Ｒ¹⁴〜Ｒ²⁰は、それぞれ独立に、水素原子、ハロゲン原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルケニル基、炭素数１〜２０のアルキニル基、炭素数１〜２０のハロアルキル基、炭素数１〜３０のアルコキシル基又は炭素数１〜２０のカルボニル基を有する基であり、またＲ¹⁶〜Ｒ²⁰のうち隣接するもの同士で飽和又は不飽和の環状構造を形成していても良い。）

(In the formula, R ^{14 to} R ²⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a carbon number. A group having a haloalkyl group of 1 to 20, an alkoxyl group of 1 to 30 carbon atoms or a carbonyl group of 1 to 20 carbon atoms, and a saturated or unsaturated cyclic structure between adjacent ones of R ^{16 to} R ²⁰ May be formed.)

Examples of the halogen atom in the general formulas (D) and (E) include fluorine, chlorine, bromine and iodine atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, An n-hexyl group, an n-heptyl group, an n-octyl group, etc. are mentioned.
The alkenyl group having 1 to 20 carbon atoms includes both linear and branched alkenyl groups, and those having 2 to 15 carbon atoms are preferable.
The alkynyl group having 1 to 20 carbon atoms includes both linear and branched alkynyl groups, and those having 2 to 15 carbon atoms are preferable.
Examples of the haloalkyl group having 1 to 20 carbon atoms include chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1, 3-dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2 -Diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropyl group, Oromethyl group, 1-fluoromethyl group, 2-fluoromethyl group, 2-fluoroisobutyl group, 1,2-difluoroethyl group, difluoromethyl group, trifluoromethyl group, pentafluoroethyl group, perfluoroisopropyl group, perfluorobutyl Group, perfluorocyclohexyl group and the like.
An alkoxyl group of the 1 to 30 carbon atoms is a group represented by -OX ^1, specific examples of X ¹ are examples similar to those described for the alkyl group.
Specific examples of the group having a carbonyl group having 1 to 20 carbon atoms include formyl group, acetyl group, propanoyl group, methoxycarbonyl group and the like.
Examples of the saturated or unsaturated cyclic structure include 4 to 12 carbon atoms such as cycloalkane having 4 to 12 carbon atoms such as cyclobutane, cyclopentane, cyclohexane, adamantane and norbornane, cyclobutene, cyclopentene, cyclohexene, cycloheptene and cyclooctene. C6-C12 cycloalkadiene such as cycloalkene, cyclohexadiene, cycloheptadiene, cyclooctadiene, aromatic ring having 6-50 carbon atoms such as benzene, naphthalene, phenanthrene, anthracene, pyrene, chrysene, acenaphthylene, etc. Is mentioned.

Specific examples of the repeating unit represented by the general formulas (D) and (E) include the following.

  Further, the amorphous organic compound is preferably one obtained by crosslinking an amino group-containing low molecular compound having a crosslinking site, and the crosslinking site of the amino group-containing low molecular compound is represented by the following general formula (1) to More preferably, it is a group represented by (4), and the amorphous organic compound is a crosslinked product obtained by adding at least one onium compound to crosslink an amino group-containing low molecular compound. preferable. Specifically, the cross-linking sites shown in the following (1) to (4) are provided in advance in the amino group-containing low molecular weight compound, and after film formation as a thin film, it is crosslinked with heat or light to be modified to a high molecular weight. The obtained thin film is particularly preferable because of excellent thermal stability and resistance to organic solvents.

(Wherein R ²¹ is the same or different at each occurrence, and is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkoxyalkyl group, an alkoxy group, or a thioalkoxy group, 4 An aryl or heteroaryl group having -18 aromatic ring atoms, or an alkenyl group having 2 to 10 carbon atoms, wherein one or more hydrogen atoms may be replaced by halogen or CN; One or more non-adjacent carbon atoms may be replaced by —O—, —S—, —CO—, —COO—, —O—CO—, and is R ^{22 the} same for each occurrence? Differently, a hydrogen atom, a linear, branched or cyclic alkyl group or alkoxyalkyl group having 1 to 20 carbon atoms, an aryl group or a heteroaryl group having 4 to 18 aromatic ring atoms, or Is an alkenyl group having 2 to 10 carbon atoms, wherein one or more hydrogen atoms may be replaced by halogen or CN, and one or more non-adjacent carbon atoms are -O-, -S -, -CO-, -COO-, -O-CO- may be substituted, and Z is the same or different at each occurrence, and the divalent group-(CR ²³ R ²⁴ ) _r- (where One or more non-adjacent carbon atoms may be replaced by -O-, -S-, -CO-, -COO-, -O-CO-), or have 4 to 40 carbon atoms A divalent aryl group or an N-, S- and / or O-heteroaryl group (which may be substituted by one or more R ²³ groups), wherein R ²³ , R ²⁴ are The same or different, a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. Group, alkoxy group, alkoxyalkyl group or thioalkoxy group, aryl group or heteroaryl group having 4 to 20 aromatic ring atoms, or alkenyl group having 2 to 10 carbon atoms, wherein 1 The above hydrogen atoms may be replaced by halogen or CN, and R ²³ or R ²⁴ groups may form a ring structure with each other or with R ²¹ or R ²² ,
r is the same or different for each occurrence and is an integer from 0 to 30;
x is the same or different for each occurrence and is an integer of 0 to 5.
The broken line here shows the bond to the amorphous organic compound. )
The low molecular weight compound is particularly preferably an organic compound having an amino group in which at least one hydrogen atom is replaced by a group of the formula (1).

Specific examples of the alkyl group having 1 to 20 carbon atoms in the general formulas (1) to (4) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, Examples include t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like.
The alkoxy group is a group represented by —OX ¹ , and specific examples of X ¹ include the same examples as those described for the alkyl group.
The thioalkoxy group is a group represented by —SX ² , and examples of X ² include the same examples as those described for the alkyl group.
Specific examples of the aryl group having 4 to 18 aromatic ring atoms include 4 to 18 fragrances among the specific examples of the aryl group having 6 to 40 nuclear carbon atoms in the general formula (A). And those having a group atom.
Specific examples of the heteroaryl group include those having 4 to 18 aromatic ring atoms among the specific examples of the heteroaryl group having 3 to 40 nuclear carbon atoms in the general formula (A). It is done.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the divalent aryl group having 4 to 40 carbon atoms or the N-, S- and / or O-heteroaryl group include an aryl group having 6 to 40 nuclear carbon atoms or a nucleus in the general formula (A). Among those mentioned as specific examples of the heteroaryl group having 3 to 40 carbon atoms, those satisfying the conditions are mentioned.
Specific examples of the ring structure include cycloalkanes having 4 to 12 carbon atoms such as cycloalkanes having 4 to 12 carbon atoms such as cyclobutane, cyclopentane, cyclohexane, adamantane and norbornane, cyclobutene, cyclopentene, cyclohexene, cycloheptene and cyclooctene. C6-C12 cycloalkadiene, such as cyclohexadiene, cycloheptadiene, cyclooctadiene, benzene, naphthalene, phenanthrene, anthracene, pyrene, chrysene, acenaphthylene, etc., aromatic ring, pyrrolidine, Examples include heterocyclic rings such as piperidine.

The crosslinking reaction is preferably initiated by light irradiation, and preferred onium compounds are diaryl iodonium salts, diaryl bromonium salts, diaryl chloronium salts, and triaryl sulfonium salts, particularly preferably diaryl iodonium salts, diaryl bromoniums. Salts, and diarylchloronium salts, where the anion can be varied, but in general, for example, PF ₆ ⁻ , SbF ₆ ⁻ , SbC ₁₆ ⁻ , BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ^- weakly nucleophilic anions of the like is selected. The ratio of the onium compound in the mixture or layer can be varied within a wide range, but the ratio is kept as low as possible so that the reaction product of the decomposition reaction does not affect the function of the organic thin film transistor as much as possible. It is preferable. On the other hand, it is necessary to ensure that this ratio is sufficient to initiate crosslinking as well as possible. The proportion of initiator (onium compound) is optimized separately for each organic compound having an amino group and for each onium compound. In general, the proportion of the onium compound in the mixture is preferably selected from 0.001 to 5% by weight, particularly preferably from 0.01 to 3% by weight, in particular from 0.1 to 2% by weight. I found out. These values are especially true for diaryliodonium compounds, and for other compounds it is quite possible that these values deviate from this. Where organic compounds having amino groups are not easily oxidized, very low proportions of onium compounds, preferably onium compounds in the range of 0.01 to 0.5% by weight, are suitable for good crosslinking In the case of very electron-rich, easily oxidizable semiconductors, a higher proportion of onium compounds, preferably in the range of 1-2% by weight, is required for good crosslinking. It was found.

The channel control layer formed by performing the crosslinking reaction as described above is preferably subjected to the state adjustment treatment described below because the degree of crosslinking can be increased. After the above light irradiation is completed, preferably in the temperature range of 50 to 250 ° C, more preferably in the temperature range of 80 to 150 ° C, preferably 0.1 to 30 minutes, more preferably 1 to 5 minutes. Adjustment processing can be performed. However, the temperature range varies depending on the amorphous organic compound used. This conditioning process increases the mobility of reactive oxetane units in the channel control layer, increases the degree of crosslinking, and provides a polymer network. The channel control layer thus obtained is substantially insoluble in common organic solvents such as THF.
Further, the channel control layer formed by performing the crosslinking reaction as described above, or the channel control layer formed by performing the crosslinking reaction as described above and then subjected to the state adjustment process, is further washed. Can be applied. The cleaning treatment can be performed on the channel control layer using a general solvent such as THF. The additives and the like in the channel control layer are removed by the cleaning process. As additives, LiAlH ₄ , MBDQ free radical anion = 2,6-dimethyl 2 ′, 6′-di-tert-butyldiquinone free radical anion, reducing agents such as hydrazine and hydrazine derivatives, tetrabutylammonium acetate or bromide The concentration of these additives is low, preferably less than 10 ⁻⁴ mol / liter, particularly preferably less than 10 ⁻⁵ mol / liter.

The crosslinking reaction that proceeds in the presence of the onium compound and is initiated by irradiation is preferably not performed in the absorption band of the onium compound, and more preferably at a wavelength that is at least 80 nm longer than the absorption maximum of the onium compound. It is particularly preferable to irradiate at a wavelength 100 nm longer than the absorption maximum of the onium compound. These figures correspond to the separation between absorption maximum and emission. This means that onium compounds cannot act directly as photoacid generators, i.e. they cannot liberate protons directly. However, cross-linking of oxetane groups occurs very efficiently and rapidly, and indeed irradiation of organic compounds with amino groups, rather than in the onium compound absorption band, under otherwise similar conditions. It has been found that the cross-linked layer is more durable when done in the absorption band. It is believed that the oxetane functionalized organic compound serves as a photosensitizer for the reaction.
Irradiation is preferably performed in the absorption band of an organic compound having an amino group, in particular at wavelengths in the range up to +/− 50 nm of the absorption maximum of the individual absorption bands. The irradiation time can be chosen very short and very good cross-linking results are still obtained. Irradiation is preferably performed for 0.01 to 10 seconds, particularly preferably for 0.1 to 3 seconds. These times correspond to light quantities of <1 mW / cm ² , and for higher light quantities, even shorter exposure times may be sufficient if appropriate.
Crosslinking does not proceed without the oxetane functionality. Therefore, the present invention is further characterized in that the irradiation is performed outside the photoacid generator absorption band, preferably at a wavelength at least 80 nm longer, particularly preferably at least 100 nm longer than the absorption maximum of the onium compound.

Another method of crosslinking is the direct oxidative initiation of the crosslinking reaction by the addition of an oxidant. Suitable oxidizing agents readily remove the reaction products from the film after cross-linking, for example, nitrosonium salts, salts of triaryl ammonium free radical cations, or volatile compounds or readily soluble compounds, for example. Other oxidizing agents that can be used, or oxidizing products whose reaction products are inert and have no adverse effect on the film during operation of the organic thin film transistor. The NO compound that can be easily handled is, for example, NO (BF ₄ ) or NO (SbF ₆ ). Tris (4-bromophenylammonium) salt is an example of a stable free radical cation. The added oxidant allows oxetane group crosslinking to be initiated. Crosslinking does not proceed without the oxetane functionality.

The above cross-linking method provides the following advantages over photo-induced cross-linking (irradiation takes place in the absorption band of the photoacid generator) according to the prior art.
1) Crosslinking can be carried out under milder conditions than is possible according to the prior art. In the case of photoacid generators, higher UV radiation is required in order to liberate protons and initiate crosslinking, while the reaction in the case of the method according to the invention is significantly lower energy (= longer). Wavelength) light. In particular, for organic compounds with amino groups that are photochemically unstable (this also applies to organic compounds with most amino groups in the case of UV radiation required to date). The cross-linking method provides obvious advantages in order to substantially avoid side reactions and decomposition in the layer due to high energy UV radiation.
2) Crosslinking proceeds more quickly and efficiently than when following the prior art. Thereby, crosslinking can be performed in a shorter time than before, which protects the material and reduces side reactions due to the shorter exposure time. In addition, shorter cross-linking times represent a clear advantage in industrial production methods. Therefore, the structuring of the device is very efficient and is possible in a shorter time than before.
3) Layers that are cross-linked by the method according to the invention with the addition of less photoacid generator still have better resistance to solvents. They are therefore better structured on the one hand, while improving the application of multiple layers on the other hand on the other hand.

Specific structural formulas of the amino group-containing low molecular weight compound are shown below, but are not limited thereto.

  The amine-based organic compounds mentioned as preferred examples of the amorphous organic compounds contained in these channel control layers can be found in, for example, the non-patent document CW Tang and SA Van Slyke, Appl. Phys. Lett. 51, 913 (1987). Thus, it may be used as a hole injection layer or a hole transport layer of an organic EL device. In the organic EL, a current flows through the amine compound layer, but in the organic TFT of the present invention, the current flows through the organic semiconductor layer along the channel control layer, which is a completely different device. In fact, when these amine compounds are used as an organic semiconductor layer, the field effect mobility is extremely small. For example, non-patent documents TPI Saragi, T. Fuhrmann-Lieker and J. Salbeck, “Comparison of Charge Transport in It is well known by Thin Films of Spiro-Linked Compounds and Their Corresponding Parent Compounds ", Advanced Functional Materials 16,966 (2006).

(Lamination of channel control layer)
The channel control layer may consist of only one layer containing an amorphous organic compound having a cross-linked or non-cross-linked ionization potential of less than 5.8 eV and a molecular weight of 1000 or more, or from a plurality of layers. The amorphous organic compound obtained by crosslinking at least one layer is particularly preferable.

(Channel control layer thickness)
The film thickness of the channel control layer in the organic TFT of the present invention is not particularly limited, and may be a film thickness necessary for smoothing the interface between the channel control layer and the organic semiconductor layer. The film thickness is preferably 1 nm to 100 nm, and more preferably 5 nm to 50 nm. This is because if the film thickness is too thick, the effect of accumulating carriers due to the gate voltage is reduced, and if it is too thin, the interface with the organic semiconductor layer is not smooth enough and carrier traps may be formed in the channel. is there.

(Method for forming channel control layer)
The method for forming the channel control layer is not particularly limited, and a known method can be applied as a method for forming the organic semiconductor layer. For example, molecular beam deposition method (MBE method), vacuum deposition method, chemical vapor deposition, dipping method of solution in which material is dissolved in solvent, spin coating method, casting method, bar coating method, roll coating method, gravure printing, inkjet, letterpress It is formed by printing, lithographic printing, intaglio printing, coating method and baking, electropolymerization, molecular beam evaporation, self-assembly from solution, and combinations thereof. Here, it is necessary to consider that the amorphous nature of the material is maintained. A particularly preferable film forming method is that the channel control layer of the present invention has a molecular weight as large as 1000 or more, so that the solution process, that is, dipping method, spin coating method, casting method, bar coating method, roll coating method, ink jet, gravure printing, letterpress printing, Printing and coating methods such as lithographic and intaglio are preferred. When these methods are used, a thin film with high smoothness can be obtained. Moreover, it is also preferable to mix a crosslinking agent and a polymerization initiator in a solution as needed, and to crosslink or polymerize by light or heat.

(Organic semiconductor layer)
The organic semiconductor used in the present invention is not particularly limited. Organic semiconductors used for organic TFTs as generally disclosed can be used.
Specific examples are shown below.

(Materials used for organic semiconductor layers)
Since a high mobility can be obtained, a crystalline material is usually used. Specifically, the following materials can be exemplified.
(1) Acenes which may be substituted, such as naphthalene, anthracene, tetracene, pentacene, hexacene, heptacene, such as 1,4-bisstyrylbenzene, 1,4-bis (2-methylstyryl) benzene, 1 , 4-bis (3-methylstyryl) benzene (4MSB), 1,4-bis (4-methylstyryl) benzene, polyphenylene vinylene, and the like, represented by C ₆ H ₅ —CH═CH—C ₆ H ₅ Compounds, oligomers and polymers of such compounds.
(2) A compound containing a thiophene ring shown below (a) A thiophene oligomer which may have a substituent such as α-4T, α-5T, α-6T, α-7T and α-8T derivatives (a) Thiophene-based polymers such as polyhexylthiophene, thiophene-based polymers such as poly (9,9-dioctylfluorenyl-2,7-diyl-co-bithiophene), (u) bisbenzothiophene derivatives, α, α′- Condensed oligothiophenes such as bis (dithieno [3,2-b: 2 ′, 3′-d] thiophene), dithienothiophene-thiophene co-oligomers, pentathienoacenes, particularly compounds having a thienobenzene skeleton or a dithienobenzene skeleton Dibenzothienobenzothiophene derivatives are preferred.
(3) Selenophene oligomers, metal-free phthalocyanines, copper phthalocyanines, lead phthalocyanines, titanyl phthalocyanines, porphyrins such as platinum porphyrin, porphyrin, benzoporphyrin, tetrathiafulvalene (TTF) and its derivatives, rubrene and its derivatives, etc. Can be mentioned.

(Organic semiconductor composing n-type organic TFT)
In the case of the organic TFT of the present invention, when it is an n-type organic TFT, particularly high mobility and excellent high-temperature stability can be obtained. As the organic semiconductor used for the n-type organic TFT, an organic semiconductor having n-channel driving ability is preferable, and specific examples thereof include the following compounds.
(1) Bipolar transport compounds such as acenes, metal-free phthalocyanines, copper phthalocyanines, fluorinated copper phthalocyanines, lead phthalocyanines, titanyl phthalocyanines, platinum porphyrins, porphyrins, benzoporphyrins, and rubrenes, polyphenylene vinylenes.
(2) A compound in which a p-type semiconductor shown below is used as a mother skeleton, and fluorine or a fluoroalkyl group such as F, CF ₃ , or C ₂ F ₅ is added thereto.
Acenes which may be substituted, such as naphthalene, anthracene, tetracene, pentacene, hexacene, heptacene, for example, 1,4-bisstyrylbenzene, 1,4-bis (2-methylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene (4 MSB), 1,4-bis (4-methylstyryl) benzene, oligomers having a styryl structure represented by _{C 6 H 5 -CH = CH-} C 6 H 5 and polyphenylene vinylene, Thiophene oligomer polyhexylthiophene, poly (9,9-dioctylfluorenyl-) which may have a substituent such as a polymer, α-4T, α-5T, α-6T, α-7T, α-8T derivatives, etc. Thiophene polymer bisbenzothiophene derivatives such as thiophene polymers such as 2,7-diyl-co-bithiophene), α, α ′ Condensed oligothiophenes such as bis (dithieno [3,2-b: 2 ′, 3′-d] thiophene), dithienothiophene-thiophene co-oligomers, pentathienoacenes, particularly compounds having a thienobenzene skeleton or a dithienobenzene skeleton , Dibenzothienobenzothiophene derivatives, selenophene oligomers, metal-free phthalocyanine, copper phthalocyanine, fluorinated copper phthalocyanine, lead phthalocyanine, titanyl phthalocyanine, porphyrins such as platinum porphyrin, porphyrin, benzoporphyrin, tetrathiafulvalene (TTF) and its derivatives .
(3) What is known alone as an n-type semiconductor, quinoid oligomers such as tetracyanoquinodimethane (TCNQ), 11,11,12,12-tetracyanonaphth-2,6-quinodimethane (TCNNQ), C60 , C70, PCBM and other fullerenes, N, N′-diphenyl-3,4,9,10-perylenetetracarboxylic acid diimide, N, N′-dioctyl-3,4,9,10-perylenetetracarboxylic acid diimide Tetracarboxylic acids such as (C8-PTCDI), NTCDA, 1,4,5,8-naphthalenetetracarboxyldiimide (NTCDI).

(Thickness and deposition method of organic semiconductor layer)
The film thickness of the organic semiconductor layer in the organic TFT of the present invention is not particularly limited, but is usually 0.5 nm to 1 μm, and preferably 2 nm to 250 nm. Within this range, high mobility and excellent stability under high temperature conditions can be obtained.
A method for forming the organic semiconductor layer is not particularly limited, and a known method can be applied. For example, a molecular beam deposition method (MBE method), a vacuum deposition method, a chemical vapor deposition method, a dipping method in which a material is dissolved in a solvent, As described above by spin coating, casting, bar coating, roll coating, etc. printing, coating and baking, electropolymerization, molecular beam deposition, self assembly from solution, and combinations thereof. It is made of a material of an organic semiconductor layer. In order to improve the field-effect mobility by improving the crystallinity of the organic semiconductor layer, a method of maintaining the substrate temperature during film formation at a high temperature is used when film formation from the gas phase (evaporation, sputtering, etc.) is used. can do. The temperature is preferably 50 to 250 ° C, and more preferably 70 to 150 ° C. In addition, the performance of the element can be improved by performing annealing after film formation regardless of the film formation method. The annealing temperature is preferably 50 to 200 ° C, more preferably 70 to 200 ° C, and the time is preferably 10 minutes to 12 hours, more preferably 1 to 10 hours. However, it is necessary to employ an annealing condition that keeps the channel control layer amorphous.

(Purity of organic compound used for channel control layer and organic semiconductor layer)
In addition, in the organic thin film transistor of the present invention, the amorphous organic compound used for the channel control layer and the organic semiconductor used for the organic semiconductor layer can have a high field effect mobility and an on / off ratio by using a high-purity one. Can be improved. Therefore, it is desirable to purify these by means of column chromatography, recrystallization, distillation, sublimation and the like as necessary. Preferably, it is possible to improve the purity by repeatedly using these purification methods or combining a plurality of methods. Furthermore, it is desirable to repeat sublimation purification at least twice as a final step of purification. By using these techniques, it is preferable to use a material having a purity of 90% or more as measured by HPLC, more preferably 95% or more, and particularly preferably 99% or more. In addition, the on / off ratio can be increased and the performance inherent to the material can be extracted.

(substrate)
The substrate in the organic TFT of the present invention plays a role of supporting the structure of the organic TFT. As a material, it is possible to use glass, an inorganic compound such as a metal oxide or nitride, a plastic film (PET, PES, PC), a metal substrate, or a composite or laminate thereof. Further, when the structure of the organic TFT can be sufficiently supported by the components other than the substrate, the substrate can be omitted. Further, a silicon (Si) wafer is often used as a material for the substrate. In this case, Si itself can be used as a gate electrode / substrate. It is also possible to oxidize the surface of Si to form SiO ₂ and use it as an insulating layer. In this case, a metal layer such as Au may be formed on the Si substrate serving as the substrate and gate electrode as an electrode for connecting the lead wire.

(electrode)
In the organic TFT of the present invention, the material for the gate electrode, the source electrode, and the drain 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-potassium alloy, magnesium / copper mixture, magnesium / silver mixture, Magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, a lithium / aluminum mixture, or the like is used.

  The electrode may be formed by means such as vapor deposition, electron beam vapor deposition, sputtering, atmospheric pressure plasma method, ion plating, chemical vapor deposition, electrodeposition, electroless plating, spin coating, printing or ink jet. Is done. Moreover, as a method of patterning as necessary, a method of forming a conductive thin film formed by using the above method using a known photolithography method or a lift-off method, on a metal foil such as aluminum or copper There is a method in which a resist is formed and etched by thermal transfer, ink jet, or the like. The thickness of the electrode formed in this way is not particularly limited as long as current conduction is present, but it is preferably in the range of 0.2 nm to 10 μm, more preferably 4 nm to 300 nm. If it is in this preferable range, the resistance is increased due to the thin film thickness, and a voltage drop does not occur. Moreover, since it is not too thick, it does not take a long time to form a film, and when another layer such as a protective layer or an organic semiconductor layer is laminated, the laminated film can be made smoothly without causing a step.

  In the organic TFT of the present invention, a source electrode, a drain electrode, a gate electrode different from the above, and a method for forming the source electrode, using a fluid electrode material such as a solution, paste, ink, or dispersion containing the above conductive material. The method of forming can be adopted. In this case, it is preferable to use a fluid electrode material containing a conductive polymer or metal fine particles containing platinum, gold, silver, and copper. The solvent or dispersion medium is preferably a solvent or dispersion medium containing 60% by mass or more, preferably 90% by mass or more of water, in order to suppress adverse effects on the organic semiconductor. As the dispersion containing metal fine particles, for example, a known conductive paste may be used, but a dispersion containing metal fine particles having a particle size of usually 0.5 nm to 50 nm, 1 nm to 10 nm is preferable. . Examples of the material of the fine metal particles include platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, and tungsten. Zinc or the like can be used. It is preferable to form an electrode using a dispersion in which these metal fine particles are dispersed in water or a dispersion medium which is an arbitrary organic solvent using a dispersion stabilizer mainly composed of an organic material. As a method for producing such a dispersion of metal fine particles, metal ions can be reduced in the liquid phase, such as a physical generation method such as gas evaporation method, sputtering method, or metal vapor synthesis method, colloid method, or coprecipitation method. And a chemical production method for producing metal fine particles, preferably disclosed in JP-A-11-76800, JP-A-11-80647, JP-A-11-319538, JP-A-2000-239853, and the like. Colloidal method, gas evaporation method described in JP-A-2001-254185, 2001-53028, 2001-35255, 2000-124157, 2000-123634, etc. This is a dispersion of produced metal fine particles.

These metal fine particle dispersions may be directly patterned by an ink jet method, or may be formed from a coating film by lithograph or laser ablation. Moreover, the patterning method by printing methods, such as a letterpress, an intaglio, a planographic printing, and screen printing, can also be used. After the electrode is formed and the solvent is dried, the metal fine particles are heat-fused by heating in a shape in the range of 100 ° C. to 300 ° C., preferably 150 ° C. to 200 ° C., if necessary. An electrode pattern having the following shape is formed.
Furthermore, a known conductive polymer whose conductivity is improved by doping or the like can be used as a material for a gate electrode, a source electrode, and a drain electrode other than the above. For example, conductive polyaniline, conductive polypyrrole, conductive polythiophene (polyethylenedioxythiophene and polystyrenesulfonic acid complex and the like), polyethylenedioxythiophene (PEDOT) and polystyrenesulfonic acid complex, and the like can be preferably used. These materials can reduce the contact resistance between the organic semiconductor layer of the source electrode and the drain electrode. These forming methods may also be patterned by an ink-jet method, or may be formed from a coating film by lithography, laser ablation, or the like. Moreover, the patterning method by printing methods, such as a letterpress, an intaglio, a planographic printing, and screen printing, can also be used.

In particular, the material for forming the source electrode and the drain electrode is preferably a material having a small electric resistance at the contact surface with the organic semiconductor layer among the examples described above. The electrical resistance at this time corresponds to the field-effect mobility when a current control device is manufactured, and it is necessary that the resistance be as small as possible in order to obtain a large mobility. This is generally determined by the magnitude relationship between the work function of the electrode material and the energy level of the organic semiconductor layer.
When the work function (W) of the electrode material is a, the ionization potential of the organic semiconductor layer is (Ip) b, and the electron affinity (Af) of the organic semiconductor layer is c, it is preferable that the following relational expression is satisfied. Here, a, b, and c are all positive values with reference to the vacuum level.

In the case of a p-type organic TFT, ba−1.5 <1.5 eV (formula (I)) is preferable, and ba−1.0 <1.0 eV is more preferable. If the above relationship can be maintained in relation to the organic semiconductor layer, a high-performance device can be obtained. In particular, it is preferable that the electrode material has a work function as large as possible, and the work function is 4.0 eV or more. The work function is preferably 4.2 eV or more.
The value of the work function of the metal is, for example, an effective metal having a work function of 4.0 eV or more described in Chemical Handbook II-493 (revised 3 edition, published by the Chemical Society of Japan, Maruzen Co., Ltd. 1983). The high work function metal is mainly Ag (4.26, 4.52, 4.64, 4.74 eV), Al (4.06, 4.24, 4.41 eV), Au (5.1, 5.37, 5.47 eV), Be (4.98 eV), Bi (4.34 eV), Cd (4.08 eV), Co (5.0 eV), Cu (4.65 eV), Fe (4.5, 4.67, 4.81 eV), Ga (4.3 eV), Hg (4.4 eV), Ir (5.42, 5.76 eV), Mn (4.1 eV), Mo (4 .53, 4.55, 4.95 eV), Nb (4.02, 4.36). 4.87 eV), Ni (5.04, 5.22, 5.35 eV), Os (5.93 eV), Pb (4.25 eV), Pt (5.64 eV), Pd (5.55 eV), Re ( 4.72 eV), Ru (4.71 eV), Sb (4.55, 4.7 eV), Sn (4.42 eV), Ta (4.0, 4.15, 4.8 eV), Ti (4.33 eV) ), V (4.3 eV), W (4.47, 4.63, 5.25 eV), Zr (4.05 eV). Among these, noble metals (Ag, Au, Cu, Pt), Ni, Co, Os, Fe, Ga, Ir, Mn, Mo, Pd, Re, Ru, V, and W are preferable. Other than metals, conductive polymers such as ITO, polyaniline and PEDOT: PSS and carbon are preferred. Even if one or more of these high work function substances are included as the electrode material, there is no particular limitation as long as the work function satisfies the formula (I).

In the case of an n-type organic TFT, it is preferable that ac−1.5 eV (formula (II)), and more preferably ac−1.0 eV. If the above relationship can be maintained in relation to the organic semiconductor layer, a high-performance device can be obtained. In particular, the work function of the electrode material is preferably as small as possible, and the work function is preferably 4.3 eV or less. More preferably, the work function is 3.7 eV or less.
As a specific example of the low work function metal, for example, it has a work function of 4.3 eV or less described in Chemistry Handbook Fundamentals II-493 (revised 3 edition, published by The Chemical Society of Japan, Maruzen Co., Ltd. 1983). What is necessary is just to select from the said list of effective metals, Ag (4.26 eV), Al (4.06, 4.28 eV), Ba (2.52 eV), Ca (2.9 eV), Ce (2.9 eV), Cs (1.95 eV), Er (2.97 eV), Eu (2.5 eV), Gd (3.1 eV), Hf (3.9 eV), In (4.09 eV), K (2.28), La (3.5 eV), Li (2.93 eV), Mg (3.66 eV), Na (2.36 eV), Nd (3.2 eV), Rb (4.25 eV), Sc (3.5 eV), Sm ( 2.7 eV), Ta (4.0, 4.15 eV), (3.1eV), Yb (2.6eV), Zn (3.63eV), and the like. Among these, Ba, Ca, Cs, Er, Eu, Gd, Hf, K, La, Li, Mg, Na, Nd, Rb, Y, Yb, and Zn are preferable. Even if the electrode material contains one or more of these low work function substances, there is no particular limitation as long as the work function satisfies the above formula (II). Au can also be used in the n-type organic TFT.
However, since the low work function metal easily deteriorates when exposed to moisture and oxygen in the atmosphere, it is desirable to coat with a stable metal in the air such as Ag or Au as necessary. The film thickness necessary for the coating is 10 nm or more, and as the film thickness increases, it can be protected from oxygen and water. However, for practical reasons, it is desirable to set it to 1 μm or less for the purpose of increasing productivity.

(Buffer layer)
In the organic thin film transistor of this embodiment, for example, a buffer layer may be provided between the organic semiconductor layer and the source and drain electrodes in order to improve carrier injection efficiency. For the n-type organic thin film transistor as the buffer layer, alkali metals such as LiF, Li ₂ O, CsF, NaCO ₃ , KCl, MgF ₂ , and CaCO ₃ used for the cathode of the organic EL element are used. A compound having a bond is desirable. Moreover, you may insert the compound used as an electron injection layer and an electron carrying layer by organic EL, such as Alq.
For p-type organic thin film transistors, cyano compounds such as FeCl ₃ , TCNQ, F ₄ -TCNQ, HAT, CFx, GeO ₂ , SiO ₂ , MoO ₃ , V ₂ O ₅ , VO ₂ , V ₂ O ₃ , MnO, Metal oxides other than alkali metals and alkaline earth metals such as Mn ₃ O ₄ , ZrO ₂ , WO ₃ , TiO ₂ , In ₂ O ₃ , ZnO, NiO, HfO ₂ , Ta ₂ O ₅ , ReO ₃ , and PbO ₂ Inorganic compounds such as ZnS and ZnSe are desirable. In many cases, these oxides cause oxygen vacancies, which are suitable for hole injection. Further, amine compounds such as TPD and NPD, and compounds such as CuPc used as a hole injection layer and a hole transport layer in an organic EL device may be used. Moreover, what consists of two or more types of said compounds is desirable.
The buffer layer has the effect of lowering the threshold voltage by lowering the carrier injection barrier and driving the organic TFT at a low voltage. There is also an effect of increasing mobility. The buffer layer only needs to be thin between the electrode and the organic semiconductor layer, and the thickness is 0.1 nm to 30 nm, preferably 0.3 nm to 20 nm.

(Insulator layer)
The material of the insulator layer in the organic TFT of the present invention is not particularly limited as long as it has electrical insulating properties and can be formed as a thin film. Metal oxide (including silicon oxide), metal nitride ( Materials having a room temperature electrical resistivity of 10 Ωcm or higher, such as silicon nitride), polymers, and organic small molecules, can be used, 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, Barium titanate, barium magnesium fluoride, lanthanum oxide, fluorine oxide, magnesium oxide, bismuth oxide, bismuth titanate, niobium oxide, strontium bismuth titanate, strontium bismuth tantalate, tantalum pentoxide, niobium tantalate Examples thereof include bismuth acid, trioxide yttrium, and combinations thereof, and silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide are preferable.
In addition, inorganic nitrides such as silicon nitride (Si ₃ N ₄ , SixNy (x, y> 0)) and aluminum nitride can also be suitably used.

Further, the insulator layer may be formed of a precursor containing an alkoxide metal, and the insulator layer is formed by coating a solution of the precursor on a substrate, for example, and subjecting it to a chemical solution treatment including heat treatment. It is formed.
The metal in the alkoxide metal is selected from, for example, a transition metal, a lanthanoid, or a main group element. Specifically, barium (Ba), strontium (Sr), titanium (Ti), bismuth (Bi), tantalum ( Ta), zircon (Zr), iron (Fe), nickel (Ni), manganese (Mn), lead (Pb), lanthanum (La), lithium (Li), sodium (Na), potassium (K), rubidium ( Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium (Ca), niobium (Nb), thallium (Tl), mercury (Hg), copper (Cu), cobalt ( Co), rhodium (Rh), scandium (Sc), yttrium (Y), and the like. Examples of the alkoxide in the alkoxide metal include, for example, alcohols including methanol, ethanol, propanol, isopropanol, butanol, isobutanol, methoxyethanol, ethoxyethanol, propoxyethanol, butoxyethanol, pentoxyethanol, heptoxyethanol, Examples thereof include those derived from alkoxy alcohols including methoxypropanol, ethoxypropanol, propoxypropanol, butoxypropanol, pentoxypropanol, heptoxypropanol, and the like.

In the present invention, when the insulator layer is made of the material as described above, polarization easily occurs in the insulator layer, and the threshold voltage of the organic TFT operation can be reduced. Among the above materials, in particular, when the insulator layer is formed of silicon nitride such as Si ₃ N ₄ , SixNy, or SiONx (x, y> 0), polarization is more likely to occur, and the threshold voltage is further reduced. be able to.
As an insulator layer using an organic compound, polyimide, polyamide, polyester, polyacrylate, photo radical polymerization system, photo cation polymerization system photo-curable resin, copolymer containing acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, A novolac resin, cyanoethyl pullulan, or the like can also be used. Others, wax, polyethylene, polychloropyrene, polyethylene terephthalate, polyoxymethylene, polyvinyl chloride, polyvinylidene fluoride, polymethyl methacrylate, polysulfone, polycarbonate, polyimide cyanoethyl pullulan, poly (vinylphenol) (PVP), poly (methyl methacrylate) (PMMA), polycarbonate (PC), polystyrene (PS), polyolefin, polyacrylamide, poly (acrylic acid), novolac resin, resole resin, polyimide, polyxylylene, epoxy resin, and polymers with high dielectric constant such as pullulan It is also possible to use materials.

As the material for the insulator layer, an organic compound having water repellency is particularly preferable. By having water repellency, the interaction between the insulator layer and the channel control layer is suppressed, and the channel control layer originally possesses Since the crystallinity can be maintained, the function of the channel control layer can be exhibited and the device performance can be improved. Examples of such compounds include polyparaxylylene derivatives described in Yasuda et al. Jpn. J. Appl. Phys. Vol. 42 (2003) pp. 6614-6618 and Janos Veres et al. Chem. Mater., Vol. 16 (2004). ) pp. 4543-4555.
Further, when such a top gate structure as shown in FIGS. 2 and 5 is used, if such an organic compound is used as a material for the insulator layer, the film can be formed with reduced damage to the organic semiconductor layer. Therefore, it is an effective method.

The insulator layer may be a mixed layer using a plurality of inorganic or organic compound materials as described above, or may be a laminated structure of these. In this case, the performance of the device can be controlled by mixing or laminating a material having a high dielectric constant and a material having water repellency as necessary.
The insulator layer may include an anodic oxide film or the anodic oxide film as a configuration. The anodized film is preferably sealed. The anodized film is formed by anodizing a metal that can be anodized by a known method. Examples of the metal that can be anodized include aluminum and tantalum, and the anodizing method is not particularly limited, and a known method can be used. An oxide film is formed by anodizing. Any electrolyte solution that can form a porous oxide film can be used as the anodizing treatment. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, sulfamic acid, benzenesulfone, and the like can be used. An acid or the like or a mixed acid obtained by combining two or more of these or a salt thereof is used. The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, the electrolyte concentration is 1 to 80% by mass, the electrolyte temperature is 5 to 70 ° C., and the current density. 0.5 to 60 a / cm ^2, voltage 1 to 100 V, the electrolysis time of 10 seconds to 5 minutes is suitable. A preferred anodizing treatment is a method in which an aqueous solution of sulfuric acid, phosphoric acid or boric acid is used as the electrolytic solution and the treatment is performed with a direct current, but an alternating current can also be used. The concentration of these acids is preferably 5 to 45% by mass, and is preferably subjected to electrolytic treatment at an electrolyte temperature of 20 to 50 ° C. and a current density of 0.5 to 20 A / cm ² for ²⁰ to 250 seconds.
As the thickness of the insulator layer, if the layer thickness is thin, the effective voltage applied to the organic semiconductor increases, so that the drive voltage and threshold voltage of the element itself can be lowered. Since the current increases, it is necessary to select an appropriate film thickness, which is usually 10 nm to 5 μm, preferably 50 nm to 2 μm, and more preferably 100 nm to 1 μm.

  As a method for forming the insulator layer, a vacuum deposition method, 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, JP-A-11-61406, 11-133205, JP-A-2000-121804, 2000-147209, 2000-185362, dry process such as atmospheric pressure plasma method, spray coating method, spin coating method, blade coating Examples include wet processes such as coating, dip coating, casting, roll coating, bar coating, and die coating, and methods such as printing and ink-jet patterning. 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.

(Formation process of organic TFT)
A method for forming the organic TFT of the present invention is not particularly limited and may be a known method. According to a desired element configuration, the substrate is charged, the gate electrode is formed, the insulator layer is formed, the channel control layer is formed, the organic semiconductor is formed. It is preferable to form a series of device manufacturing steps from layer formation, source electrode formation, and drain electrode formation without exposure to the atmosphere, because the device performance can be prevented from being impaired due to atmospheric moisture or oxygen due to contact with the atmosphere. When it is unavoidable that the atmosphere must be exposed to the atmosphere once, the process after the organic semiconductor layer is formed is not exposed to the atmosphere at all. In the case of B, the surface on which the source electrode and the drain electrode are partially stacked on the insulating layer) is cleaned and activated by ultraviolet irradiation, ultraviolet / ozone irradiation, oxygen plasma, argon plasma, etc., and then the organic semiconductor layer is stacked. It is preferable. In addition, some p-type TFT materials are exposed to the atmosphere once, and the performance is improved by adsorbing oxygen or the like. Therefore, depending on the material, the material is appropriately exposed to the atmosphere.
Further, for example, in consideration of the influence on the organic semiconductor layer such as oxygen and water contained in the atmosphere, a gas barrier layer may be formed on the whole or a part of the outer peripheral surface of the organic transistor element. As the material for forming the gas barrier layer, those commonly used in this field can be used, and examples thereof include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl chloride, polyvinylidene chloride, and polychlorotrifluoroethylene. . Furthermore, the inorganic substance which has the insulation illustrated in the said insulator layer can also be used.

Example 1 (Manufacture of organic TFT)
An organic thin film transistor was produced by the following procedure. First, the surface of a Si substrate (also used as a P-type specific resistance 1 Ωcm gate electrode) was oxidized by a thermal oxidation method, and a 300 nm thermal oxide film was formed on the substrate to form an insulator layer. Further, after the SiO ₂ film formed on one side of the substrate is completely removed by dry etching, chromium is deposited to a thickness of 20 nm by sputtering, and further gold (Au) is sputtered by 100 nm by sputtering. A film was formed and taken out as an electrode. This substrate was ultrasonically cleaned with a neutral detergent, pure water, acetone and ethanol for 30 minutes each, and further subjected to ozone cleaning.
Next, a high molecular weight amorphous organic compound (TFB, ionization potential (Ip) = 5.31 eV, weight average molecular weight: 30,000) having a repeating unit represented by the following formula on the insulator layer is reduced to 0. 6% by mass was dissolved, and a spin coater was used to form a film at a rotation speed of 1500 rpm for 30 seconds, followed by drying at 180 ° C. for 30 minutes to form a 20 nm-thick channel control layer.

  Next, the substrate formed up to the TFB was placed in a vacuum deposition apparatus (ULVAC, EX-400), and PTCDI-C13 represented by the following formula was deposited at a deposition rate of 0.05 nm / s and an organic semiconductor having a thickness of 50 nm. Deposited as a layer. Finally, a gold film having a thickness of 50 nm was formed through a metal mask, so that a source electrode and a drain electrode that were not in contact with each other were formed so that the interval (channel length L) was 75 μm. At that time, an organic thin film transistor was manufactured by forming a film so that the width of the source electrode and the drain electrode (channel width W) was 5 mm (see FIG. 6).

A gate voltage of 0 to 100 V was applied to the gate electrode of the obtained organic thin film transistor, and a current was applied by applying a voltage between the source and drain. In this case, electrons are induced in the channel region (between source and drain) of the organic semiconductor layer, and operate as an n-type transistor. As a result, the on / off ratio of the current between the source and drain electrodes in the current saturation region was 5 × 10 ⁵ . Moreover, it was 8.3 * 10 ^<-2 > cm ^{< 2} > / Vs when the electron field effect mobility (micro | micron | mu) was computed from the following formula (A).
I _D = (W / 2L) · Cμ · (V _G −V _T ) ² (A)
Where I _D is the source-drain current, W is the channel width, L is the channel length, C is the capacitance per unit area of the gate insulator layer, V _T is the gate threshold voltage, and V _G is the gate voltage. . Further, when this organic TFT was stored at 50 ° C. for 200 hours, the mobility still remained as high as 4.3 × 10 ⁻² cm ² / Vs.

Example 2
In Example 1, an organic thin film transistor was produced in exactly the same manner except that PCBM represented by the following formula was used instead of PTCDI-C13 as the material of the organic semiconductor layer.
The PCBM layer was prepared by dissolving PCBM in chloroform at a concentration of 10 mg / ml, forming a film at a rotation speed of 2000 rpm for 60 seconds using a spin coater, and drying at 120 ° C. for 0 minute to form a 100 nm thick organic semiconductor layer. The results are shown in Table 1.

Example 3
In Example 1, C60 is used instead of PTCDI-C13 as the material of the organic semiconductor layer, and an amorphous organic compound (Ip = 5.29 eV, molecular weight) represented by the following formula (i) is used instead of TFB as the channel control layer. : 1355.71) was used to produce an organic thin film transistor in exactly the same manner. The results are shown in Table 1.

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Example 4
In Example 1, C60 is used instead of PTCDI-C13 as the material of the organic semiconductor layer, and an amorphous organic compound (Ip = 5.16 eV, molecular weight) represented by the following formula (ii) is used instead of TFB as the channel control layer. 1820.43) was used, and the device was fabricated in the same manner.

Example 5
In Example 1, a photocrosslinked product of a low molecular compound represented by the following formula (iii) (Ip = 5.45 eV, weight average molecular weight: 100,000) was used instead of TFB, and PTCDI-C13 was used as the organic semiconductor. A device was fabricated in exactly the same manner except that PCBM was used. The method of forming the PCBM is the same as that in the second embodiment.

Photocrosslinking of the low molecular compound represented by the above formula (iii) was performed as follows. 2 g of a low molecular weight compound represented by the above formula (iii) in THF (4% by mass) and a chloroform solution of {4-[(2-hydroxytetradecyl) oxy] phenyl} phenyliodonium hexafluoroantimonate (0.1 (Mass%) 2 g was mixed as a starting material, and an appropriate amount was dropped using a spin coater, and a film was formed at a rotational speed of 1500 rpm for 30 seconds. Thereafter, a standard UV hand lamp having a 4 W tube (UV-A, 365 nm) was used, and the exposure was performed for 3 seconds with the distance between the substrate and the exposure source set to 5 cm. To complete the crosslinking process, the membrane was conditioned at 100 ° C. for about 1 minute. Thereafter, THF was dropped on the film by dropping with an appropriate amount of solvent in a spin coater, rinsed twice with a spin coater at 1500 rpm for 30 seconds, and further dried at 80 ° C. for 15 minutes.
This process step was performed under inert gas. The transistor characteristics are shown in Table 1.

Example 6
In Example 1, a device was manufactured in the same manner as in Example 1 except that a low molecular weight compound oxidant (Ip = 5.45 eV, weight average molecular weight: 80,000) represented by the above formula (iii) was used instead of TFB. Was made. The oxidant crosslinking of the low molecular compound represented by the above formula (iii) was performed as follows. THF solution (4% by mass) of low molecular weight compound 2g Chloroform solution (0.012% by mass) of nitrosonium hexafluoroantimonate (NO ⁺ SbF ₆ ⁻ ) 2g is mixed, and an appropriate amount is added dropwise using a spin coater, and the rotational speed is 1500 rpm. After forming at 30 ° C. for 30 seconds and drying at 100 ° C. for 30 minutes, chloroform was dropped onto the film, rinsed twice with a spin coater at 1500 rpm for 30 seconds, and further dried at 80 ° C. for 15 minutes.
This process step was performed under inert gas. The transistor characteristics are shown in Table 1.

Example 7
In Example 1, a device was fabricated in the same manner except that a polymer compound having a repeating unit represented by the above formula (iV) (Ip = 5.50 eV, weight average molecular weight: 120,000) was used instead of TFB. Produced. The transistor characteristics are shown in Table 1.

Comparative Example 1
An organic TFT was produced in the same manner as in Example 1 except that the channel control layer was not used. The results are shown in Table 1.

Comparative Example 2
An organic TFT was produced in exactly the same manner as in Example 2 except that NPD (Ip = 5.45 eV, molecular weight: 588.74) represented by the following formula was used instead of TFB. When the PCBM was formed by coating, the channel control layer NPD was eroded by the PCBM coating operation, and the PCBM film was non-uniform and did not exhibit FET characteristics. The results are shown in Table 1.

  From Table 1, it was clarified that when a channel control layer having an Ip of less than 5.8 is provided, the mobility is improved, and when a compound having a molecular weight of 1000 or more is used, the storage stability is improved.

  As described above in detail, the organic TFT of the present invention is useful as a transistor because it has high mobility and high storage stability.

It is a figure which shows an example of the element structure of a general organic TFT. It is a figure which shows an example of the element structure of the organic TFT of this invention. It is a figure which shows an example of the element structure of the organic TFT of this invention. It is a figure which shows an example of the element structure of the organic TFT of this invention. It is a figure which shows an example of the element structure of the organic TFT of this invention. It is a figure which shows an example of the element structure of the organic TFT in the Example of this invention.

Claims (9)

  An organic thin film transistor in which at least three terminals of a gate electrode, a source electrode and a drain electrode, an insulator layer and an organic semiconductor layer are provided on a substrate, and a source-drain current is controlled by applying a voltage to the gate electrode, A channel control layer having a thickness of 1 to 100 nm is provided between the insulator layer and the organic semiconductor layer. The channel control layer has an ionization potential of less than 5.8 eV and a molecular weight of 1000 An organic thin film transistor comprising the amorphous organic compound as described above.   The organic thin film transistor according to claim 1, wherein the amorphous organic compound is an amino group-containing organic compound.   The organic thin film transistor according to claim 1 or 2, wherein the amorphous organic compound is a hydrocarbon compound having a condensed aromatic ring.   The organic thin-film transistor in any one of Claims 1-3 in which the said organic-semiconductor layer contains the organic semiconductor which has n channel drive capability. The organic thin-film transistor according to claim 2, wherein the amorphous organic compound is represented by the following general formula (A).

(In the formula, Ar ^{1 to} Ar ⁶ are each independently a substituted or unsubstituted aryl group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted heteroaryl group having 3 to 40 nuclear carbon atoms; Ar ¹ And Ar ² and Ar ⁵ and Ar ⁶ may each independently be linked by a single bond to form a carbazolyl group,
R ^{1 to} R ⁴ are each independently a halogen atom, a carboxyl group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 40 carbon atoms, A substituted or unsubstituted alkynyl group having 2 to 40 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 40 carbon atoms,
n, m, p, and q are each independently an integer of 0 to 4,
L is a divalent linking group represented by the following general formula (B) or (C). )
_{^{- (Ar 7) a - (}} Ar 8) b - (Ar 9) c - (B)
(In the formula, Ar ^{7 to} Ar ⁹ are each independently a substituted or unsubstituted divalent aryl group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted divalent heteroaryl having 3 to 40 nuclear carbon atoms. Group,
a, b, and c are each independently an integer of 1 to 3; )

Wherein R ⁵ and R ⁶ are each independently a halogen atom, a carboxyl group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted carbon number 2 to 40 An alkenyl group, a substituted or unsubstituted alkynyl group having 2 to 40 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 40 carbon atoms,
R ⁵ and R ⁶ may be linked to each other to form a ring structure. ) The organic thin film transistor according to claim 2, wherein the amorphous organic compound is an amino group-containing polymer compound having a repeating unit represented by the following general formula (D) or (E).

(In formula, R < ⁷ > -R < ¹³ > is respectively independently a hydrogen atom, a halogen atom, a C1-C20 alkyl group, a C1-C20 alkenyl group, a C1-C20 alkynyl group, carbon number. A group having 1 to 20 haloalkyl groups, an alkoxyl group having 1 to 30 carbon atoms, or a carbonyl group having 1 to 20 carbon atoms, and a saturated or unsaturated cyclic structure between adjacent ones of R ^{9 to} R ¹³ May form,
d is 1 or 2. )

(In the formula, R ^{14 to} R ²⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a carbon number. A group having a haloalkyl group of 1 to 20, an alkoxyl group of 1 to 30 carbon atoms or a carbonyl group of 1 to 20 carbon atoms, and a saturated or unsaturated cyclic structure between adjacent ones of R ^{16 to} R ²⁰ May be formed.)   The organic thin-film transistor according to claim 2, wherein the amorphous organic compound is obtained by crosslinking an amino group-containing low molecular compound having a crosslinking site. The organic thin film transistor according to claim 7, wherein a crosslinking site of the amino group-containing low molecular compound is a group represented by the following general formulas (1) to (4).

(Wherein R ²¹ is the same or different at each occurrence, and is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkoxyalkyl group, an alkoxy group, or a thioalkoxy group, 4 An aryl or heteroaryl group having -18 aromatic ring atoms, or an alkenyl group having 2 to 10 carbon atoms, wherein one or more hydrogen atoms may be replaced by halogen or CN; One or more non-adjacent carbon atoms may be replaced by —O—, —S—, —CO—, —COO—, —O—CO—, and is R ^{22 the} same for each occurrence? Differently, a hydrogen atom, a linear, branched or cyclic alkyl group or alkoxyalkyl group having 1 to 20 carbon atoms, an aryl group or heteroaryl group having 4 to 18 aromatic ring atoms, or Is an alkenyl group having 2 to 10 carbon atoms, wherein one or more hydrogen atoms may be replaced by halogen or CN, and one or more non-adjacent carbon atoms are -O-, -S -, -CO-, -COO-, -O-CO- may be substituted, and Z is the same or different at each occurrence, and the divalent group-(CR ²³ R ²⁴ ) _r- (where One or more non-adjacent carbon atoms may be replaced by -O-, -S-, -CO-, -COO-, -O-CO-), or have 4 to 40 carbon atoms A divalent aryl group or an N-, S- and / or O-heteroaryl group (which may be substituted by one or more R ²³ groups), wherein R ²³ , R ²⁴ are The same or different, a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. Group, alkoxy group, alkoxyalkyl group or thioalkoxy group, aryl group or heteroaryl group having 4 to 20 aromatic ring atoms, or alkenyl group having 2 to 10 carbon atoms, wherein 1 The above hydrogen atoms may be replaced by halogen or CN, and R ²³ or R ²⁴ groups may form a ring structure with each other or with R ²¹ or R ²² ,
r is the same or different for each occurrence and is an integer from 0 to 30;
x is the same or different for each occurrence and is an integer of 0 to 5.
A broken line here shows the coupling | bonding to the said low molecular weight compound. )   The organic thin-film transistor according to claim 7 or 8, wherein the amorphous organic compound is a crosslinked body obtained by adding at least one onium compound and crosslinking the amino group-containing low-molecular compound.

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