JP6417626B2 - Organic thin film transistor - Google Patents

Description

The present invention relates to an organic thin film transistor.
This application claims priority based on Japanese Patent Application No. 2015-005413 for which it applied to Japan on January 14, 2015, and uses the content here.

As an organic insulator having a low threshold voltage and a driving voltage and high charge mobility with the organic active layer, (i) an organic-inorganic hybrid material, and (ii) one or more organic metal compounds and / or one kind An organic-inorganic insulator-forming composition containing the above organic polymer and (iii) a solvent that dissolves the components (i) and (ii) is known (see Patent Document 1). The organic-inorganic hybrid material is a polymer obtained by subjecting an organic silane compound or an organic silane compound to a hydrolysis reaction and a condensation reaction in an organic solvent using an acid or base catalyst and water, and the organic metal compound is titanium. (IV) It is known to be a titanium compound such as n-butoxide.
In addition, as a new organic insulator composition having excellent solubility in an organic solvent and a monomer and having a high dielectric constant, i) an organic / inorganic metal hybrid material represented by the following formula 1; There are known organic insulator compositions comprising a monomer and / or an organic polymer, and iii) a solvent that dissolves the components i) and ii). The compound represented by the following formula (1) is known to be obtained by subjecting an organosilane compound and an organometallic compound to a hydrolysis reaction or polycondensation reaction in an organic solvent using an acid or base catalyst and water. (See Patent Document 2).

In the above formula, M is a metal atom, and R ¹ , R ² and R ³ are each independently substituted with a (meth) acryloyl group, (meth) acryloyloxy group or epoxy group having 2 to 5 carbon atoms. R ¹ , R ⁵ and R ⁶ are each independently a hydrogen atom; an alkyl group having 1 to 10 carbon atoms, and the like.

JP 2005-120371 A JP 2006-70029 A

However, even if an insulating layer is provided using the organic insulator composition as described above, there is still room for improvement in terms of maintaining adhesiveness with the organic semiconductor layer and having practical carrier mobility. there were.
An object of this invention is to provide the organic thin-film transistor which maintains adhesiveness with an organic-semiconductor layer, and has practical carrier mobility.

As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by providing an organic semiconductor layer on a substrate on which a specific insulating layer is laminated, and the present invention is completed. It came to.
That is, the present invention includes the following aspects.
(1) An organic thin film transistor provided with a gate insulating layer comprising an organic-inorganic composite thin film containing the following a) and b).
a) Formula (I):

(In the formula, R represents an organic group in which a carbon atom is directly bonded to Si, X represents a hydroxyl group or a hydrolyzable group. N represents 1 or 2, and when n is 2, each R is the same or different. And when (4-n) is 2 or more, each X may be the same or different.) And b) a cured product of an electromagnetic radiation curable compound.
(2) The organosilicon compound represented by the formula (I) is
An organosilicon compound Si1 having a R solubility parameter SP1 determined by the Fedors estimation method that is 1.6 or more smaller than the solubility parameter SP2 of the electromagnetic radiation curable compound determined by the Fedors estimation method;
The solubility parameter SP1 is composed of an organosilicon compound Si2 that is less than 1.6 less than or equal to or greater than the solubility parameter SP2.
The organic thin-film transistor according to (1), wherein a molar ratio Si1: Si2 between the organosilicon compound Si1 and the organosilicon compound Si2 is 5: 5 to 10: 0.
(3) The organosilicon compound represented by the formula (I) is represented by the formula (I-1):

(In the formula, n represents 1 or 2, and when n is 2, R ¹ may be the same or different from each other, R ¹ is an organic group, and one or more of R ¹ are vinyl groups. And X represents a hydroxyl group or a hydrolyzable group, which may be the same or different from each other.
Formula (I-2)

(In the formula, n represents 1 or 2, and when n is 2, R ² may be the same or different, and R ² is a vinyl group-containing carbonization in which a carbon atom is directly bonded to Si in the formula. X represents an organic group other than a hydrogen group, X represents a hydroxyl group or a hydrolyzable group, and may be the same or different from each other. Consisting of condensate,
{[Compound of Formula (I-1)] + [If present, a unit derived from the compound of Formula (I-1) in the hydrolysis condensate]} / {[Compound of Formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula (I in hydrolysis condensate) Unit derived from compound of I-2)]} × 100 = 30 to 100 mol%, and
{[Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-2) in hydrolysis condensate]} / {[compound of formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula (I in hydrolysis condensate) Unit derived from compound of I-2)]} × 100 = 0 to 70 mol%. The organic thin film transistor according to (1), wherein

(4) A display device comprising the organic thin film transistor according to any one of (1) to (3).
(5) A sensor comprising the organic thin film transistor according to any one of (1) to (3).
(6) An electronic tag having the organic thin film transistor according to any one of (1) to (3).

  The organic thin film transistor of the present invention maintains adhesiveness with the organic semiconductor layer and exhibits practical carrier mobility.

In the organic thin-film transistor of Example 1 is a graph showing a transistor characteristic of I _D -V _G when applying the source-drain voltage of V _{D =} -30 V is a saturated region. 3 is a graph showing transfer characteristics in the organic thin film transistor of Example 1. It is a graph which shows the carrier mobility (field effect mobility) in the saturation area | region with respect to the gate voltage of the organic thin-film transistor of Example 1. FIG. It is a graph which shows the carrier mobility (effective mobility) in the linear area | region with respect to a gate voltage. 4 is a graph showing output characteristics of the organic thin film transistor of Example 1. In the organic thin-film transistor of Example 2 is a graph showing a transistor characteristic of I _D -V _G when applying the source-drain voltage of V _{D =} -30 V is a saturated region. It is a graph which shows the transfer characteristic in the organic thin-film transistor of Example 2. It is a graph which shows the carrier mobility (field effect mobility) in the saturation area | region with respect to the gate voltage of the organic thin-film transistor of Example 2. FIG. (B) It is a graph which shows the carrier mobility (effective mobility) in the linear area | region with respect to gate voltage. 4 is a graph showing output characteristics of an organic thin film transistor of Example 2.

<Organic thin film transistor>
The organic thin film transistor of the present invention includes an organic semiconductor layer, a source electrode and a drain electrode that are in contact with the organic semiconductor layer, and a gate electrode that is located on the organic semiconductor layer via an insulating layer on the substrate. It is preferable.

[substrate]
An example of the substrate is a resin substrate. As resin substrates, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate A substrate made of (TAC), cellulose acetate propionate (CAP) or the like can be exemplified, and among them, a substrate made of polyethylene naphthalate (PEN) or polyimide (PI) is preferable. The shape of the substrate may be any shape such as a film shape, a sheet shape, and a plate shape, but a film shape is particularly preferable.

  The substrate may be made of an unstretched film or a stretched film. Moreover, even if it is a single layer film, the laminated film which laminated | stacked two or more layers by means, such as a lamination and a coating, may be sufficient.

  Although the thickness of a board | substrate is not restrict | limited in particular, 1-1000 micrometers is preferable and 3-500 micrometers is more preferable.

[Gate electrode, source electrode, drain electrode]
The material for forming the source electrode, the drain electrode and the gate electrode is not particularly limited as long as it is a conductive material. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, Tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, tin oxide / antimony, indium tin oxide (ITO), fluorine-doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium , Beryllium, sodium, magnesium, potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloy, magnesium, lithium, aluminum, magnesium / copper mixture Magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, lithium / aluminum mixture, etc. are used, especially platinum, gold, silver, copper, aluminum, indium, ITO, carbon, chromium A / gold / chrome laminate is preferred. Alternatively, a known conductive polymer whose conductivity is improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, conductive polythiophene, a complex of polyethylenedioxythiophene and polystyrenesulfonic acid, or the like is also preferably used. Among them, those having low electric resistance at the contact surface with the organic semiconductor layer are preferable.

  As a method for forming an electrode, a method for forming an electrode using a known photolithographic method or a lift-off method, using a conductive thin film formed by a method such as vapor deposition or sputtering using the above as a raw material, or a metal foil such as aluminum or copper A method of etching using a resist by thermal transfer, ink jet, or the like can be given. Alternatively, a conductive polymer solution or dispersion, or a conductive fine particle dispersion may be directly patterned by ink jetting, or may be formed from a coating film by lithography or laser ablation. Furthermore, a method of patterning an ink containing a conductive polymer or conductive fine particles, a conductive paste, or the like by a printing method such as relief printing, intaglio printing, planographic printing, or screen printing can also be used.

  Metal fine particle dispersions used in such electrodes can be produced in the liquid phase by physical production methods such as gas evaporation, sputtering, and metal vapor synthesis, colloidal methods, and coprecipitation methods. Examples of the chemical production method include reducing metal and producing fine metal particles. Preferably, JP-A-11-76800, JP-A-11-80647, JP-A-11-319538, and JP-A-2000-239853 are preferred. In the gas described in the colloidal method described in JP-A-2001-254185, 2001-53028, 2001-35255, 2000-124157, 2000-123634, etc. It is a fine metal particle dispersion produced by an evaporation method. After forming a layer using these metal fine particle dispersions, the solvent is dried, and further, heat treatment is performed in the range of 100 to 300 ° C., preferably 150 to 200 ° C. Form.

[Insulation layer]
The insulating layer is made of (A) an organic-inorganic composite thin film as a gate insulating film.

  The organic-inorganic composite thin film constituting the insulating layer contains at least a) a condensate of an organosilicon compound and b) a cured product of an electromagnetic radiation curable compound.

≪a) Condensate of organosilicon compound≫
The organosilicon compound used in the present invention is represented by the following formula (I).

  In the formula, R represents an organic group in which a carbon atom is directly bonded to Si, and X represents a hydroxyl group or a hydrolyzable group. n represents 1 or 2, and when n is 2, each R may be the same or different, and when (4-n) is 2 or more, each X may be the same or different.

Here, examples of the “organic group in which a carbon atom is directly bonded to Si” represented by R include an optionally substituted hydrocarbon group.
The hydrocarbon group of the “optionally substituted hydrocarbon group” is preferably a hydrocarbon group having 1 to 30 carbon atoms, such as an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, an alkenyl group, a cycloalkenyl group. Group, alkynyl group, aryl group, arylalkyl group, arylalkenyl group and the like.

  The “hydrocarbon group” may have an oxygen atom, a nitrogen atom, or a silicon atom.

  As the alkyl group, a linear or branched alkyl group having 1 to 10 carbon atoms is preferable. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n -Pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, n-heptyl group, n-octyl group, n-nonyl group, isononyl group, n-decyl group and the like. Furthermore, examples of the long-chain alkyl group having more than 10 carbon atoms include a lauryl group, a tridecyl group, a myristyl group, a pentadecyl group, a palmityl group, a heptadecyl group, and a stearyl group.

  The cycloalkyl group is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

  As the cycloalkylalkyl group, a cycloalkylalkyl group having 4 to 20 carbon atoms is preferable. For example, a cyclopropylmethyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a cycloheptylethyl group, a cyclooctylethyl group, a cyclo A decylmethyl group, a cyclotetradecylmethyl group, a cyclooctadecylmethyl group, etc. are mentioned.

  As the alkenyl group, a linear or branched alkenyl group having 2 to 10 carbon atoms is preferable, and it is a linear or branched alkenyl group having 2 to 10 carbon atoms having a carbon-carbon double bond at any one or more positions. Meaning, for example, ethenyl group, 1-propen-1-yl group, 2-propen-1-yl group, 1-propen-2-yl group, 1-buten-1-yl group, 2-butene- 1-yl group, 3-buten-1-yl group, 1-buten-2-yl group, 3-buten-2-yl group, 1-penten-1-yl group, 4-penten-1-yl group, 1-penten-2-yl group, 4-penten-2-yl group, 3-methyl-1-buten-1-yl group, 1-hexen-1-yl group, 5-hexen-1-yl group, 1 -Hepten-1-yl group, 6-hepten-1-yl group, 1-octen-1-y Group, 7-octen-1-yl group, 1,3-butadiene-1-yl group.

  As the cycloalkenyl group, a cycloalkenyl group having 3 to 8 carbon atoms is preferable, which means an alkenyl group having 3 to 8 carbon atoms having a carbon-carbon double bond at one or more positions and having a cyclic portion. For example, 1-cyclopenten-1-yl group, 2-cyclopenten-1-yl group, 1-cyclohexen-1-yl group, 2-cyclohexen-1-yl group, 3-cyclohexen-1-yl group and the like can be mentioned. It is done.

  As the alkynyl group, an alkynyl group having 2 to 10 carbon atoms is preferable. For example, ethynyl group, 1-propyn-1-yl group, 2-propyn-1-yl group, 1-butyn-1-yl group, 3- Butyn-1-yl group, 1-pentyn-1-yl group, 4-pentyn-1-yl group, 1-hexyn-1-yl group, 5-hexyn-1-yl group, 1-heptin-1-yl Group, 1-octyn-1-yl group, 7-octyn-1-yl group and the like.

  The cycloalkylalkyl group is preferably a group in which a cycloalkyl group having 3 to 10 carbon atoms and an alkyl group having 1 to 10 carbon atoms are bonded, for example, cyclopropylmethyl group, cyclopropylpropyl group, cyclobutylmethyl group, cyclopentyl. Examples thereof include a methyl group, a cyclopentylethyl group, a cyclohexylethyl group, and a cycloheptylmethyl group.

  The aryl group means a monocyclic or polycyclic aryl group. In the case of a polycyclic aryl group, in addition to a fully unsaturated group, a partially saturated group is also included. Specifically, a phenyl group, a naphthyl group, Examples include an azulenyl group, an indenyl group, an indanyl group, and a tetralinyl group, and an aryl group having 6 to 10 carbon atoms is preferable.

  The arylalkyl group is preferably a group in which an aryl group having 6 to 10 carbon atoms and an alkyl group having 1 to 10 carbon atoms are bonded, such as benzyl group, phenethyl group, 3-phenyl-n-propyl group, 4-phenyl group. -N-butyl group, 5-phenyl-n-pentyl group, 8-phenyl-n-octyl group, naphthylmethyl group and the like can be mentioned.

  As the arylalkenyl group, a group in which an aryl group having 6 to 10 carbon atoms and an alkenyl group having 2 to 10 carbon atoms are bonded is preferable. For example, a styryl group, a 3-phenyl-1-propen-1-yl group, a 3- Phenyl-2-propen-1-yl group, 4-phenyl-1-buten-1-yl group, 4-phenyl-3-buten-1-yl group, 5-phenyl-1-penten-1-yl group, Examples include 5-phenyl-4-penten-1-yl group, 8-phenyl-1-octen-1-yl group, 8-phenyl-7-octen-1-yl group, and naphthylethenyl group.

  Examples of the “hydrocarbon group having an oxygen atom” include an oxirane ring (epoxy group) group such as an alkoxyalkyl group, an epoxyalkyl group, and a glycidoxyalkyl group, an acryloxymethyl group, and a methacryloxymethyl group. .

  Here, the alkoxyalkyl group is preferably a group in which an alkoxy group having 1 to 6 carbon atoms and an alkyl group having 1 to 6 carbon atoms are bonded. For example, a methoxymethyl group, 2-methoxyethyl group, 3-ethoxy-n -Propyl group etc. are mentioned.

  The epoxyalkyl group is preferably a linear or branched epoxyalkyl group having 3 to 10 carbon atoms, such as a glycidyl group, a glycidylmethyl group, a 2-glycidylethyl group, a 3-glycidylpropyl group, a 4-glycidylbutyl group, Alkyl groups containing linear epoxy groups such as 3,4-epoxybutyl group, 4,5-epoxypentyl group, 5,6-epoxyhexyl group; β-methylglycidyl group, β-ethylglycidyl group, β- Propyl glycidyl group, 2-glycidyl propyl group, 2-glycidyl butyl group, 3-glycidyl butyl group, 2-methyl-3-glycidyl propyl group, 3-methyl-2-glycidyl propyl group, 3-methyl-3,4- Epoxybutyl group, 3-ethyl-3,4-epoxybutyl group, 4-methyl-4,5-epoxypentyl group, 5- Such as an alkyl group containing branched epoxy groups, such as chill-5,6 epoxy hexyl group.

  Examples of the glycidoxyalkyl group include a glycidoxymethyl group and a glycidoxypropyl group.

The “hydrocarbon group having a nitrogen atom” has —NR ′ ₂ (wherein R ′ represents a hydrogen atom, an alkyl group or an aryl group, and each R ′ may be the same as or different from each other). Or a group having —N═CR ″ ₂ (wherein R ″ represents a hydrogen atom, an alkyl group or an aryl group, and each R ″ may be the same as or different from each other). Examples of the alkyl group include the same groups as described above, and examples of the aryl group include a phenyl group, a naphthyl group, an anthracen-1-yl group, and a phenanthren-1-yl group.

For example, the group having —NR ′ ₂ includes a —CH ₂ NH ₂ group, a —CH ₂ (CH ₂ ) ₂ NH ₂ group, a —CH ₂ NHCH ₃ group, and the like. -N = Examples of the group having a _{CR '' 2, -CH 2 N} = CHCH 3 _{group, -C 2 N = C (CH} 3) 2 _{group, -CH 2 CH 2 N = CHCH} 3 group, _-CH 2 N ═CHPh group, —CH ₂ N═C (Ph) CH ₃ group and the like.

  Examples of the “optionally substituted” substituent include a halogen atom, an alkyl group, an alkenyl group, an aryl group, and a methacryloxy group. Examples of the alkyl group, alkenyl group, and aryl group are the same as those in R.

Among the above, vinyl group, a group having an oxirane ring, -NR 'group having ₂ or -N = CR,' group with _'2, from the viewpoint of mineralization of the surface of the organic-inorganic composite film, preferred groups It is.

  In the formula (I), n represents 1 or 2, and n = 1 is particularly preferable. When n is 2, each R may be the same or different. Moreover, these can be used individually by 1 type or in combination of 2 or more types.

  In the formula (I), X represents a hydroxyl group or a hydrolyzable group. When (4-n) of formula (I) is 2 or more, each X may be the same or different. A hydrolyzable group is, for example, a group that can be hydrolyzed to form a silanol group or a siloxane condensate by heating at 25 ° C. to 100 ° C. in the presence of no catalyst and excess water. Specifically, an alkoxy group, an acyloxy group, a halogen atom, an isocyanate group, an unsubstituted or substituted amino group, and the like can be mentioned. The acyloxy group of number 1-6 is preferable.

  Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, and a t-butoxy group. Examples of the group (however, the carbon number does not include carbon of the carbonyl group) include an acetoxy group and a benzoyloxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The (A) organic silicon compound condensate contained in the organic-inorganic composite thin film means a condensate of these organosilicon compounds and / or a further condensate of the organosilicon compounds.
The blending ratio of the organic silicon compound condensate is preferably 2 to 98% by mass, more preferably 5 to 50% by mass, and still more preferably 5 to 30% by mass with respect to the solid content of the whole (A) organic-inorganic composite thin film. .

Specific examples of preferred embodiments of the organosilicon compound used in the present invention include the following mixtures a-1), a-2) and a-3).
a-1) A compound represented by formula (I-1).

In the formula, n represents 1 or 2, and when n is 2, R ¹ may be the same or different, R ¹ is an organic group, and one or more of R ¹ are vinyl group-containing carbonized Represents a hydrogen group. X represents a hydroxyl group or a hydrolyzable group, and may be the same or different from each other. Here, as an organic group and a hydrolysable group, the thing as described in Formula (I) is illustrated preferably. Examples of the vinyl group-containing hydrocarbon group include an alkenyl group (preferably a C2-C8 alkenyl group) such as a vinyl group, an allyl group, a 3-butenyl group, and a 4-hexenyl group.

  a-2) A compound represented by formula (I-2).

In the formula, n represents 1 or 2, and when n is 2, R ² may be the same or different, and R ² is a vinyl group-containing hydrocarbon group in which a carbon atom is directly bonded to Si in the formula. Represents an organic group other than X represents a hydroxyl group or a hydrolyzable group, and may be the same or different from each other. Here, examples of the organic group other than the vinyl group-containing hydrocarbon group include those excluding a vinyl group-containing organic group such as an alkenyl group and an arylalkenyl group from those described in the formula (I). Examples of the hydrolyzable group include those described in formula (I).

a-3) Hydrolytic condensates thereof, if present.
The compound represented by the formula (I-2) and the hydrolysis condensate containing the compound as a unit do not necessarily exist. Hydrolysis condensate is a dimer or the like in which compounds are hydrolyzed and condensed to form a siloxane bond, and only a compound of formula (I-1) or formula (I-2) is hydrolyzed and condensed. It may be a product obtained by hydrolytic condensation of the compound of formula (I-1) and the compound of formula (I-2), or two or more of these may be mixed.

{[Compound of Formula (I-1)] + [If present, a unit derived from the compound of Formula (I-1) in the hydrolysis condensate]} / {[Compound of Formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula (I in hydrolysis condensate) The unit derived from the compound of I-2)]} × 100 is preferably 30 to 100 mol%, more preferably 30 to 95 mol%.
On the other hand, {[compound of formula (I-2)] + [if present, a unit derived from the compound of formula (I-2) in the hydrolysis condensate]} / {[compound of formula (I-1) ] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, in hydrolysis condensate The unit derived from the compound of formula (I-2)]} × 100 is preferably 0 to 70 mol%, more preferably 5 to 70 mol%.
The average particle size of the hydrolysis-condensation product is preferably 2 nm to 100 nm, and more preferably 5 nm to 30 nm. If the average particle size is larger than 100 nm, the film becomes cloudy, the solution becomes unstable, and gelation tends to occur. If the average particle size is smaller than 2 nm, the coating properties may be affected.

These can be used alone or in combination of two or more.
When organic silicon compounds are used in combination, for example, a combination of vinyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane and a combination of vinyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane can be preferably exemplified.

Moreover, as an organosilicon compound represented by the formula (I-1), an organosilicon compound having 3 or less carbon atoms in R ¹ is blended in an amount of 30 mol% or more, more preferably 50 to 100 mol%, and R ¹ It is more preferable that the organosilicon compound having 4 or more carbon atoms is contained in an amount of 70 mol% or less, more preferably 0 to 50 mol%.

  As another preferred embodiment of the organosilicon compound used in the present invention, specifically, the R-solubility parameter SP1 obtained by the Fedors estimation method is the electromagnetic radiation curable compound obtained by the Fedors estimation method. The organosilicon compound Si1 is 1.6 or more, preferably 1.6 to 8.5, more preferably 1.6 to 7.2 smaller than the solubility parameter SP2, and the solubility parameter SP1 is the solubility parameter SP2. The organic silicon compound Si2 is smaller than 1.6 or smaller than or equal to the solubility parameter SP2, and the molar ratio Si1: Si2 between the organosilicon compound Si1 and the organosilicon compound Si2 is 5: 5 to 10: 0, Preferably, it is 9: 1 to 10: 0.

The organosilicon compound differs depending on the type of electromagnetic radiation curable compound used. Since the solubility parameter (SP value) of the organosilicon compound and the electromagnetic radiation curable compound can be calculated based on the Fedors' estimation method, the organosilicon compound and the electromagnetic radiation curable compound can be calculated based on the precalculated SP value. A combination can be determined.
In the formula (I), when n is 2 and R is different, the SP value having the larger numerical value is set as the SP1, and the combination with the electromagnetic radiation curable compound is determined.

  Examples of organosilicon compounds that can be used in the present invention are listed in Table 1 below together with SP values. In addition, Compound No. 1-No. 15 corresponds to the compound of the above formula (I-1).

≪b) Cured product of electromagnetic radiation curable compound≫
The electromagnetic radiation curable compound used in the present invention is a compound or resin having a functional group that causes a polymerization reaction by irradiation with electromagnetic radiation in the presence of a polymerization initiator added as necessary. As electromagnetic radiation, ultraviolet rays, X-rays, radiation, ionizing radiation, ionizing radiation (α, β, γ rays, neutron rays, electron beams) can be used, and light having a wavelength of 350 nm or less is preferable.
Irradiation with electromagnetic radiation can be performed using, for example, a known apparatus such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, an excimer lamp, a carbon arc lamp, or a xenon arc lamp. The light source is preferably a light source including light having any wavelength in the range of 150 to 350 nm, and more preferably a light source including light having any wavelength in the range of 250 to 310 nm.
Moreover, as an irradiation light quantity of the light irradiated in order to fully harden the composition for organic-inorganic composite thin film formation, about 0.1-100 J / cm < ² > is mentioned, for example, Film hardening efficiency (irradiation energy and film hardening) considering the degree of relationship), it is preferably about 1~10J / cm ^2, and more preferably about 1~5J / cm ^2.

  Examples of electromagnetic radiation curable compounds include (meth) acrylate compounds, epoxy compounds, vinyl compounds other than acrylate compounds, and the like. The number of functional groups is not particularly limited as long as it is 1 or more. Examples of electromagnetic radiation curable compounds that can be used in the present invention are listed in Table 2 below together with SP values.

  In addition to the above compounds, the acrylate compounds include polyurethane (meth) acrylate, polyester (meth) acrylate, epoxy poly (meth) acrylate, polyamide (meth) acrylate, polybutadiene (meth) acrylate, and polystyryl (meth). Acrylate, polycarbonate diacrylate, and the like can be used. The SP value of these compounds is in the range of 9 to 11 depending on the type of the functional group contained.

The epoxy poly (meth) acrylate can be obtained, for example, by an esterification reaction between an oxirane ring of a low molecular weight bisphenol type epoxy resin or a novolac epoxy resin and acrylic acid.
The polyester (meth) acrylate is obtained, for example, by esterifying the hydroxyl group of a polyester oligomer having hydroxyl groups at both ends with acrylic acid, obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol. Alternatively, it can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with acrylic acid.
Urethane (meth) acrylate is a reaction product of an isocyanate compound obtained by reacting a polyol with diisocyanate and an acrylate monomer having a hydroxyl group, and examples of the polyol include polyester polyol, polyether polyol, and polycarbonate diol. .

  As a commercial item of urethane (meth) acrylate used in the present invention, for example, trade names manufactured by Arakawa Chemical Industries, Ltd .: Beam Set (registered trademark) 102, 502H, 505A-6, 510, 550B, 551B, 575, 575CB , EM-90, EM92, Sannopco Co., Ltd. trade name: Photomer (registered trademark) 6008, 6210, Shin-Nakamura Chemical Co., Ltd. trade name: NK Oligo U-2PPA, U-4HA, U-6HA, H -15HA, UA-32PA, U-324A, U-4H, U-6H, manufactured by Toa Gosei Co., Ltd. Trade names: Aronix (registered trademark) M-1100, M-1200, M-1210, M-1310, M -1600, M-1960, Kyoeisha Chemical Co., Ltd. trade name: AH-600, AT606, UA-306H, Nippon Kayaku Co., Ltd. trade name: Kayarad (Registered trademark) UX-2201, UX-2301, UX-3204, UX-3301, UX-4101, UX-6101, UX-7101, trade name manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: Purple light (registered trademark) UV-1700B , UV-3000B, UV-6100B, UV-6300B, UV-7000, UV-7600B, UV-2010B, manufactured by Negami Kogyo Co., Ltd. Trade names: Art Resin (registered trademark) UN-1255, UN-5200, HDP- 4T, HMP-2, UN-901T, UN-3320HA, UN-3320HB, UN-3320HC, UN-3320HS, H-61, HDP-M20, manufactured by Daicel UCB Co., Ltd. Trade name: Ebecryl (registered trademark) I 6700, 204, 205, 220, 254, 1259, 1290K, 1748, 20 And the like can be given 2,2220,4833,4842,4866,5129,6602,8301.

Among these, polyester (meth) acrylate, polyurethane (meth) acrylate, and epoxy poly (meth) acrylate are preferable, and polyurethane (meth) acrylate is more preferable.
Although molecular weight does not have a limit as long as it melt | dissolves in the composition for organic inorganic composite thin film formation, 500-50,000 are preferable as a mass mean molecular weight, and 1,000-10,000 are more preferable.

The amount of the cured product of the electromagnetic radiation curable compound in the organic / inorganic composite thin film is determined based on the solid content of the entire organic / inorganic composite thin film (condensate of organosilicon compound, cured product of the electromagnetic radiation curable compound, and as necessary. To 98% by mass, more preferably 50 to 95% by mass, and still more preferably 70 to 95% by mass.
In the present invention, a polymerization initiator can be mixed. Examples of such an initiator include known compounds such as a compound that generates a cationic species by electromagnetic irradiation and a compound that generates an active radical species by electromagnetic irradiation. An agent can be mentioned.

<(A) Method for producing organic-inorganic composite thin film>
[Preparation of organic / inorganic composite thin film forming solution]
The solution for forming the (A) organic-inorganic composite thin film in the present invention is not only an organic silicon compound and an electromagnetic radiation curable compound, but also a metal compound having a polymerization initiator, silanol condensation catalyst ability, water, and / or a solvent as appropriate. It is prepared by mixing.
Specific examples of the metal compound that acts as a silanol condensation catalyst include metal alkoxides, metal chelate compounds, organic acid metal salts, or their hydrolysis condensates, and more specifically, Examples thereof include tetraisopropoxytitanium, diisopropoxybisacetylacetonatotitanium, or a hydrolysis condensate thereof.

  The preparation method is not particularly limited. Specifically, a metal compound such as a metal chelate compound is mixed with a solvent, a predetermined amount of water is added, (partial) hydrolysis is performed, and then the organosilicon compound is added. Addition (partial) hydrolysis, while preparing a heat or electromagnetic radiation curable compound in a solvent and adding a polymerization initiator or curing agent as necessary, and then mixing both solutions Can be illustrated. These four components can be mixed at the same time, and the method of mixing the organosilicon compound and the metal compound, after mixing the organosilicon compound and the metal compound, adding water (partially), A method of mixing separately (partially) hydrolyzed organosilicon compounds and metal compounds can be mentioned. It is not always necessary to add water or a solvent, but it is preferable to add (partly) a hydrolyzate by adding water. The amount of the predetermined amount of water depends on the type of the metal compound. For example, when the metal compound is a metal compound having two or more hydroxyl groups or hydrolyzable groups, the amount of water is 0.5 with respect to 1 mol of the metal compound. It is preferable to use at least mol of water, and more preferably 0.5 to 2 mol of water. Moreover, when a metal compound is a metal chelate compound or organic acid metal salt, it is preferable to use 5-100 mol water with respect to 1 mol of metal chelate compounds or organic acid metal salt, and 5-20 mol water is used. It is more preferable.

  a) As a condensate of an organosilicon compound, a product obtained by (partially) hydrolyzing an organosilicon compound using a known silanol condensation catalyst may be used.

The composition for forming an organic-inorganic composite thin film preferably contains water and / or a solvent in addition to the above components.
The solvent to be used is not particularly limited. For example, aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane and octane; alicyclic hydrocarbons such as cyclohexane and cyclopentane. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers such as tetrahydrofuran and dioxane; esters such as ethyl acetate and butyl acetate; amides such as N, N-dimethylformamide and N, N-dimethylacetamide Sulphoxides such as dimethyl sulphoxide; alcohols such as methanol and ethanol; polyhydric alcohol derivatives such as ethylene glycol monomethyl ether and ethylene glycol monomethyl ether acetate; These solvents can be used alone or in combination of two or more.

Examples of the silanol condensation catalyst include acids and bases in addition to the metal compounds.
Examples of the acid include organic acids and mineral acids. Specifically, examples of the organic acid include acetic acid, formic acid, oxalic acid, carbonic acid, phthalic acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid, and the like. Examples of the mineral acid include hydrochloric acid, nitric acid, boric acid, borohydrofluoric acid, and the like.
Here, a photoacid generator that generates an acid by light irradiation, specifically, diphenyliodonium hexafluorophosphate, triphenylphosphonium hexafluorophosphate, and the like are also included.
Examples of the base include strong bases such as tetramethylguanidine and tetramethylguanidylpropyltrimethoxysilane; organic amines, carboxylic acid neutralized salts of organic amines, quaternary ammonium salts and the like.

  As solid content in the solution for organic-inorganic composite thin film formation in this invention, 1-98 mass% is preferable, It is more preferable that it is 10-60 mass%, It is still more preferable that it is 15-45 mass%.

[(A) Production of organic-inorganic composite thin film]
(A) The organic-inorganic composite thin film can be produced by applying the above-described organic-inorganic composite thin film forming solution on a resin substrate, and drying and / or heating, plasma treatment, or UV ozone treatment.

(A) The organic-inorganic composite thin film is a film in which the concentration of carbon atoms at a depth of 10 nm from the surface, measured by ESCA analysis, is 20% or less less than the concentration of carbon atoms at a depth of 100 nm from the surface. preferable.
Here, the “carbon atom concentration” means the molar concentration of carbon atoms when (total metal atom + oxygen atom + carbon atom) is 100%. The same applies to the concentrations of other elements.

  As a coating method of the organic / inorganic composite thin film forming solution, a known coating method can be used. For example, dipping method, spray method, bar coating method, roll coating method, spin coating method, curtain coating method, gravure printing method. , Silk screen method, ink jet method and the like. Moreover, it does not restrict | limit especially as a film thickness to form, For example, it is about 0.1-20 micrometers.

  For example, the drying / heating treatment of the film formed by applying the organic-inorganic composite thin film forming solution is preferably performed at 40 to 200 ° C for about 0.5 to 120 minutes, and at 60 to 160 ° C, 1 to More preferably, it is performed for about 60 minutes, more preferably about 60 to 120 ° C. for about 1 to 60 minutes.

  The insulating layer has the above structure as a gate insulating film. Therefore, in the organic thin film transistor, the affinity between the insulating layer and the organic semiconductor layer is improved, and the leakage current can be suppressed. Organic thin film transistors have practical carrier mobility.

[Organic semiconductor layer]
As a material of the organic semiconductor layer constituting the organic thin film transistor, a π-conjugated material is used, for example, polypyrrole, poly (N-substituted pyrrole), poly (3-substituted pyrrole), poly (3,4-disubstituted pyrrole). Polypyrroles such as: polythiophene, poly (3-substituted thiophene), poly (3,4-disubstituted thiophene), polythiophenes such as polybenzothiophene, polyisothianaphthenes such as polyisothianaphthene, polychenylene vinylene Such as polychenylene vinylenes; poly (p-phenylene vinylenes) such as poly (p-phenylene vinylene), polyaniline, poly (N-substituted aniline), poly (3-substituted aniline), poly (2,3- Substituted anilines) and the like, polyacetylenes such as polyacetylene; Polydiacetylenes such as lenene, polyazulenes such as polyazulene, polypyrenes such as polypyrene, polycarbazoles such as polycarbazole and poly (N-substituted carbazole), polyselenophenes such as polyselenophene; polyfuran, polybenzofuran, etc. Poly (p-phenylene) s such as poly (p-phenylene); polyindoles such as polyindole; polypyridazines such as polypyridazine; naphthacene, pentacene, hexacene, heptacene, dibenzopentacene, tetrabenzopentacene , Pyrene, dibenzopyrene, chrysene, perylene, coronene, terylene, ovarene, quaterylene, circaanthracene and other polyacenes; a part of carbon of polyacenes such as N, S and O atoms, carbonyl group Derivatives substituted with functional groups such as triphenodioxazine, triphenodithiazine, hexacene-6,15-quinone, etc .; polymers such as polyvinylcarbazole, polyphenylene sulfide, polyvinylene sulfide; JP-A-11-195790 The polycyclic condensates described in 1) can be used.

  Further, for example, α-sexual thiophene α, ω-dihexyl-α-sexual thiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (α, which is a thiophene hexamer having the same repeating unit as those polymers. Oligomers such as 3-butoxypropyl) -α-sexithiophene and styrylbenzene derivatives can also be preferably used.

  Furthermore, metal phthalocyanines such as copper phthalocyanine and fluorine-substituted copper phthalocyanine described in JP-A-11-251601; naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N′-bis (4-trifluoromethyl) Benzyl) naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N′-bis (1H, 1H-perfluorooctyl), N, N′-bis (1H, 1H-perfluorobutyl) and N, N '-Dioctylnaphthalene 1,4,5,8-tetracarboxylic acid diimide derivative, naphthalene 2,3,6,7 tetracarboxylic acid diimide and other naphthalene tetracarboxylic acid diimides, and anthracene 2,3,6,7-tetra Condensed ring tet such as anthracene tetracarboxylic acid diimides such as carboxylic acid diimide Carboxylic acid diimides; C60, C70, C76, C78, C84 etc. fullerenes; carbon nanotubes such as SWNT, merocyanine dyes, etc. dyes such hemicyanine dyes and the like.

  Among these π-conjugated materials, thiophene, vinylene, chelenylene vinylene, phenylene vinylene, p-phenylene, a substituent thereof, or two or more of these are used as a repeating unit, and the number n of the repeating units is 4 to 4 At least 1 selected from the group consisting of an oligomer of 10 or a polymer in which the number n of repeating units is 20 or more, a condensed polycyclic aromatic compound such as pentacene, fullerenes, condensed ring tetracarboxylic diimides, and metal phthalocyanine Species are preferred.

  Other organic semiconductor materials include tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTTF-iodine complex, TCNQ-iodine complex. Organic molecular complexes such as can also be used. Furthermore, (sigma) conjugated polymers, such as polysilane and polygermane, and organic-inorganic hybrid material as described in Unexamined-Japanese-Patent No. 2000-260999 can also be used.

  The organic semiconductor layer can be produced by vacuum deposition, molecular beam epitaxial growth, ion cluster beam method, low energy ion beam method, ion plating method, CVD method, sputtering method, plasma polymerization method, electrolytic polymerization method, chemical polymerization method, etc. Examples of the method include a combination method, a spray coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a roll coating method, a bar coating method, a die coating method, and an LB method. However, among these, in terms of productivity, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, or a method capable of easily and precisely forming a thin film using an organic semiconductor solution, or A casting method or the like is preferable. Furthermore, a gap casting method or an edge casting method, which is a special casting method, is preferable for controlling the orientation of the molecular compound constituting the organic semiconductor layer.

  In addition, as described in Advanced Material 1999 No. 6, p. 480 to 483, a precursor such as pentacene is soluble in a solvent, a target organic material formed by heat treatment of a precursor film formed by coating A thin film may be formed.

  Although there is no restriction | limiting in particular as a film thickness of an organic-semiconductor layer, The characteristic of the obtained element is largely influenced by the film thickness of the active layer which consists of organic semiconductors, and the film thickness changes with organic semiconductors. Is preferably 1 μm or less, particularly preferably 10 to 300 nm.

[Dopant layer]
The organic thin film transistor of the present invention preferably includes a dopant layer between the source and drain electrodes and the organic semiconductor layer. Examples of the dopant layer include materials having functional groups such as acrylic acid, acetamide, dimethylamino group, cyano group, carboxyl group, and nitro group, benzoquinone derivatives, tetracyanoethylene and tetracyanoquinodimethane, and derivatives thereof. Materials that accept electrons, such as materials having functional groups such as amino, triphenyl, alkyl, hydroxyl, alkoxy, and phenyl groups, substituted amines such as phenylenediamine, anthracene, benzo Even if it contains a material that becomes a donor as an electron donor, such as anthracene, substituted benzoanthracenes, pyrene, substituted pyrene, carbazole and its derivative, tetrathiafulvalene and its derivative, etc. Good.

The doping treatment means introducing an electron-donating molecule (acceptor) or an electron-donating molecule (donor) into the organic semiconductor layer as a dopant. Therefore, the doped organic semiconductor layer is a thin film containing the condensed polycyclic aromatic compound and the dopant. A well-known thing can be employ | adopted as a dopant used for this invention.
Examples of the material used for the dopant layer further include ferric chloride, TCNQ, F4TCNQ (tetrafluorotetracyanoquinodimethane), fullerene and derivatives thereof, and F4TCNQ is preferable.

[Self-assembled monolayer]
In order to increase the charge mobility of the organic semiconductor layer between the insulating layer and the organic semiconductor layer, a self-assembled monolayer (SAM) is preferably provided. Moreover, it is also possible to control the threshold voltage by providing the SAM. Specifically, as the component for forming SAM, octadecyltrichlorosilane, octadecyltrimethoxysilane, decyltrichlorosilane, decyltrimethoxysilane, β-phenethyltrichlorosilane, β-phenethyltrimethoxysilane (β-PTS), Examples include trichloromethylsilazane, alkane phosphoric acid, alkane phosphonic acid, alkane sulfonic acid, alkane carboxylic acid and the like.

  The organic thin film transistor of the present invention can be used by being incorporated into various electronic devices. For example, as a drive element that is actively driven in various display devices such as a liquid crystal display device, an organic EL display device, and electronic paper, a transistor element used in various sensors, and a memory together with a capacitor in an electronic tag (IC tag) Can be used as an element.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples at all.

[Production Example 1] (Preparation of organic / inorganic composite thin film forming solution)
Diisopropoxybisacetylacetonate titanium (Nippon Soda Co., Ltd., T-50, titanium oxide equivalent solid content: 16.5% by weight) 30.3 g Solmix (registered trademark) AP-7 (Nippon Alcohol Sales Co., Ltd. The product was dissolved in 58.4 g), and then 11.3 g of ion-exchanged water (10-fold mol with respect to titanium) was slowly added dropwise with stirring to cause hydrolysis. One day later, the solution was filtered to obtain a yellow transparent titanium oxide nano-dispersion [A-1] having a titanium oxide equivalent concentration of 5% by weight. The average particle size of titanium oxide was 4.1 nm and was monodispersed.
As an organosilicon compound, vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-1003) (SP value: 7.00) and 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503) A liquid [B-1] in which (SP value: 9.48) was mixed at a molar ratio of 7/3 (= vinyltrimethoxysilane / 3-methacryloxypropyltrimethoxysilane) was used.
Said [A-1] and [B-1] were mixed so that it might become element ratio (Ti / Si = 1/9), and liquid [C-1] stirred for 12 hours was produced. The solid content of [C-1] was 29.2% by weight.
As an electromagnetic radiation curable compound, urethane acrylate oligomer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., purple light UV1700B) (SP value: 10-11) was dissolved in methyl isobutyl ketone (MIBK) so as to be 40% by weight. As a photopolymerization initiator, 1-hydroxy-cyclohexyl phenyl ketone (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in this solution so as to be 4% by weight based on the solid content of the urethane acrylate oligomer, and the solution [D-1 ] Was produced.
The above-mentioned [C-1] solution and [D-1] solution are mixed so that the solid content ratio is 10% by weight / 90% by weight = [C-1] / [D-1]. A thin film forming solution [E-1] was prepared.

[Example 1]
A polyethylene naphthalate film (PEN film) was used as the substrate. On the PEN film, using a vacuum deposition machine “EX-400” (vacuum degree: 1.3 × 10 ⁻⁴ Pa) manufactured by ULVAC, a chromium (Cr) layer having a thickness of 3 nm, gold having a thickness of 20 nm ( An Au) layer and a 5 nm thick chromium (Cr) layer were laminated in this order to form a gate electrode.
Next, on the gate electrode, using a spin coater (2000 rpm), the organic-inorganic composite thin film forming solution [E-1] prepared in Production Example 1 is diluted 4 times with a diluent, and coated and dried in 20 seconds. (Hot air drying, 80 ° C., 3 minutes), UV irradiation (condensing high-pressure mercury lamp, 160 W / cm, lamp height 9.8 cm, cumulative irradiation amount about 500 mJ / cm ² ) to obtain an insulating layer with a film thickness of 650 nm It was.
Next, a PEN film having an insulating layer formed on the gate electrode was cut into 2.5 × 2.5 cm ² .
Next, an organic semiconductor layer was formed in accordance with a coating method developed by the present inventors (edge casting: Appl. Phys. Exp. 2, 111501 (2009)). That is, a piece of silicon substrate for holding a solution (hereinafter also referred to as “solution holding structure”) was placed on the cut PEN film. While tilting the substrate, an organic semiconductor solution (C10-DNBDT, manufactured by Pie Crystal Co., Ltd.) was hung on the edge of the solution holding structure at 75 ° C. The crystal was attached to the substrate while the crystal was growing as the solvent evaporated, and the crystal growth was completed in a few minutes. In this state, it was left under reduced pressure for 1 hour at room temperature and further under reduced pressure at 100 ° C. for 8 hours to completely dry the crystal film (film thickness: 10 to 100 nm).
In order to produce source / drain electrodes on this organic semiconductor layer, a 1 nm thick dopant layer made of F4-TCNQ was formed using a channel (L: 100 μm, W: 2000 μm) shadow mask, and then gold was used. A bottom gate / top contact type organic thin film transistor was fabricated by vapor deposition with a thickness of 40 nm.

About the produced organic thin-film transistor, the transport characteristic was measured using the semiconductor parameter analyzer (model number "keithley 4200", the Keithley Instruments company make).
FIG. 1A shows the result of the saturation region of the organic thin film transistor of Example 1, and FIG. 1B shows the result of the linear region of the organic thin film transistor of Example 1.
From the result of FIG. 1A, the carrier mobility and the threshold voltage in the saturation region of the organic thin film transistor of Example 1 were calculated using the following formula (1).

Here, I _D is a drain current, W is the channel width, L is channel length of, mu is the carrier mobility, C _OX is per unit area of the gate insulating film capacitance, V _G is the gate voltage, V _T is It is a threshold voltage.
The drain voltage (V _D ) was −30 V, and the mobility was measured by changing the gate voltage (V _G ) from 20 V to −30 V. A carrier mobility of 5.2 cm ² / Vs could be obtained in the saturation region. The threshold voltage was 1.9V.
From the result of FIG. 1B, the carrier mobility and the threshold voltage in the linear region of the organic thin film transistor of Example 1 were calculated using the following formula (2).

The drain voltage (V _D ) was set to −1 V, and the mobility was measured while changing the gate voltage (V _G ) from 20 V to −30 V. In the linear region, a carrier mobility of 4.5 cm ² / Vs could be obtained. The threshold voltage was -4.3V.

  Further, FIG. 2A and FIG. 2B show changes in carrier mobility with respect to the gate voltage obtained from the above formulas (1) and (2). 2A shows the carrier mobility (field effect mobility) in the saturation region of the organic thin film transistor of Example 1, and FIG. 2B shows the carrier mobility (effective mobility) in the linear region of the organic thin film transistor of Example 1. is there. From FIG. 2A and FIG. 2B, it was confirmed that effective carrier mobility was shown with respect to the gate voltage.

FIG. 3 shows the output characteristics of the organic thin film transistor of Example 1. The drain current (I _D ) and the gate voltage (V _G ), and the drain current (I _D ) and the drain voltage (V _D ) all show a clear correlation, and the organic transistor of Example 1 has excellent characteristics. It was confirmed to show.

[Example 2]
In Example 2, before the organic semiconductor layer was formed on the PEN film on which the gate electrode and the insulating layer were formed, the self of β-phenethyltrichlorosilane (β-PTS) (Shin-Etsu Chemical LP-1990) was formed on the insulating layer. The difference from Example 1 is that an organized monolayer was formed. The self-assembled monolayer is prepared by subjecting a PEN film having a gate electrode and an insulating layer formed thereon to UV ozone cleaning for 10 minutes using a UV ozone cleaning device (manufactured by Sen Special Light Source Co., Ltd.), and further in β-phenethyltrichlorosilane It was immersed for 18 hours and formed on the insulating layer.

Also in Example 2, the transport properties were measured in the same manner as in Example 1. 4A shows the result of the saturation region of the organic thin film transistor of Example 2, and FIG. 4B shows the result of the linear region of the organic thin film transistor of Example 2.
From the results of FIG. 4A, the carrier mobility and threshold voltage in the saturation region were calculated. As in Example 1, the drain voltage (V _D ) was −30 V, and the mobility was measured by changing the gate voltage (V _G ) from 20 V to −30 V. A carrier mobility of 4.5 cm ² / Vs could be obtained in the saturation region. The threshold voltage was 16V.
Further, the carrier mobility and the threshold voltage in the linear region were calculated from the result of FIG. 4B. Similar to Example 1, the drain voltage (V _D ) was set to −1 V, and the gate voltage (V _G ) was changed from 20 V to −30 V to measure mobility. A carrier mobility of 4.0 cm ² / Vs could be obtained in the linear region. The threshold voltage was 29V. It can be confirmed that the threshold voltage can be controlled without significantly changing the carrier mobility by forming the self-assembled monolayer.

  Similarly to Example 1, FIGS. 5A and 5B show changes in carrier mobility with respect to the gate voltage obtained from the above formulas (1) and (2). FIG. 5A shows the carrier mobility (field effect mobility) in the saturation region of the organic thin film transistor of Example 2, and FIG. 5B of the organic thin film transistor of Example 2 shows the carrier mobility (effective mobility) in the linear region. is there.

FIG. 6 shows the output characteristics of the organic thin film transistor of Example 2. The drain current (I _D ) and the gate voltage (V _G ), and the drain current (I _D ) and the drain voltage (V _D ) all show a clear correlation, and the organic transistor of Example 2 has excellent characteristics. It was confirmed to show.

  The organic thin film transistor of the present invention maintains adhesiveness with the organic semiconductor layer and exhibits practical carrier mobility.

Claims (10)

a ) Formula (I):

(In the formula, R represents an organic group in which a carbon atom is directly bonded to Si, X represents a hydroxyl group or a hydrolyzable group. N represents 1 or 2, and when n is 2, each R is the same or different. And when (4-n) is 2 or more, each X may be the same or different.) A condensate of an organosilicon compound represented by: b) a cured product of an electromagnetic radiation curable compound ,
An organic thin film transistor provided with a gate insulating layer comprising an organic-inorganic composite thin film containing
The organosilicon compound represented by the formula (I) is
Formula (I-1):

(In the formula, n represents 1 or 2, and when n is 2, R ¹ may be the same or different from each other, R ¹ is an organic group, and one or more of R ¹ are vinyl groups. And X represents a hydroxyl group or a hydrolyzable group, which may be the same or different from each other,
Formula (I-2):

(In the formula, n represents 1 or 2, and when n is 2, R ² may be the same or different, and R ² is a vinyl group-containing carbonization in which a carbon atom is directly bonded to Si in the formula. An organic group other than a hydrogen group, X represents a hydroxyl group or a hydrolyzable group, and may be the same or different from each other), and if present, their hydrolysis condensates And consist of
{[Compound of Formula (I-1)] + [If present, a unit derived from the compound of Formula (I-1) in the hydrolysis condensate]} / {[Compound of Formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula (I in hydrolysis condensate) Unit derived from compound of I-2)} × 100 = 30 to 95 mol%, and
{[Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-2) in hydrolysis condensate]} / {[compound of formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula (I in hydrolysis condensate) Unit derived from compound of I-2)} × 100 = 5-70 mol%,
An organic thin film transistor . Said {[compound of formula (I-1)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate]} / {[compound of formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula in hydrolysis condensate Unit derived from compound (I-2)]} × 100 = 70 to 95 mol%, and
Said {[compound of formula (I-2)] + [if present, unit derived from compound of formula (I-2) in hydrolysis condensate]} / {[compound of formula (I-1)] + [Compound of formula (I-2)] + [if present, unit derived from compound of formula (I-1) in hydrolysis condensate] + [if present, formula in hydrolysis condensate (I-2) of a compound derived units]} × 100 = 5 ~ 30 mole%
The organic thin film transistor according to claim 1. The organosilicon compound represented by the formula (I) is a combination of vinyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane, or a combination of vinyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane. The organic thin-film transistor of Claim 1 or 2. A substrate,
  An organic semiconductor layer provided on the substrate;
  A source electrode and a drain electrode in contact with the organic semiconductor layer;
  The organic thin-film transistor as described in any one of Claims 1-3 further provided with the gate electrode located through the said gate insulating film with respect to the said organic-semiconductor layer. The organic thin-film transistor according to any one of claims 1 to 4, wherein the electromagnetic radiation curable compound is polyester (meth) acrylate, polyurethane (meth) acrylate, or epoxy poly (meth) acrylate. The organic thin film transistor according to claim 5, wherein the electromagnetic radiation curable compound is polyurethane (meth) acrylate.   The organic thin film transistor according to any one of claims 1 to 6, wherein the cured product of the electromagnetic radiation curable compound is contained in an amount of 70 to 95% by mass with respect to a solid content of the whole organic-inorganic composite thin film. Display device comprising an organic thin film transistor according to any one of claims 1-7. Sensor having an organic thin film transistor according to any one of claims 1-7. Electronic tag having an organic thin film transistor according to any one of claims 1-7.

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