TW201547075A - Organic thin-film transistor and organic electronic device - Google Patents

Abstract

This invention provides an organic thin-film transistor that exhibits low property variability and high carrier mobility, a high-performance differential-amplifier circuit using said thin-film transistor, and an organic electronic device. This organic thin-film transistor, which has a gate electrode, a gate-insulating film, a source electrode, a drain electrode, and an organic semiconductor film, is characterized in that the organic semiconductor film comprises an organic semiconductor that can be represented by formula (1), the surface energy between said organic semiconductor and the material used for the gate-insulating film is less than or equal to 2.0 mJ/m2, and the organic semiconductor film is created via a printing process. (R1 through R6 each independently represent a hydrogen atom, a C1-20 alkyl group, a group that can be represented by formula (2), or the like.) (R7 represents a C3-10 cycloalkyl group or the like, and Y represents a C1-6 divalent alkyl group or the like.).

Description

Organic thin film transistor and organic electronic device

The present invention relates to an organic thin film transistor and an organic electronic device, More specifically, it relates to an organic thin film transistor and an organic electronic device having a small carrier mobility and a small error in performance such as a limit voltage.

Organic semiconductor device represented by organic thin film transistor, recent In recent years, attention has been paid to features not found in inorganic semiconductor devices such as energy saving, low cost, and softness.

The organic semiconductor device is composed of several materials such as an organic semiconductor layer, a substrate, an insulating layer, an electrode, and the like, and an organic semiconductor layer that functions as a charge carrier has a color at the center of the device.

However, the performance of the organic semiconductor device is due to Since the organic material of the organic semiconductor layer has a carrier mobility of about, it is desirable to provide an organic material capable of providing high carrier mobility.

As a method of producing an organic semiconductor layer, a vacuum vapor deposition method in which an organic material is vaporized under a high-temperature vacuum, a coating method in which an organic material is dissolved in a suitable solvent, and the like is applied. Since coating can be carried out by using a printing technique without using a high-temperature and high-vacuum condition, it is considered to be an economically preferable process, and an organic semiconductor layer having high coating property and excellent carrier mobility is desired.

In addition, previously known printed organic thin film transistors are faced An important problem is that the performance error is large (see, for example, Patent Document 1 and Patent Document 2), and a printed organic thin film transistor having a small performance error is desired. The general carrier mobility and performance error are in a trade-off relationship. Low-molecular-based semiconductors with high crystallinity tend to have high performance errors on the other hand, and polymer semiconductors have opposite trends. .

It is known to use specific low molecular semiconductors, but in organic thin Among the properties of the film transistor, a printing type organic thin film transistor having a small carrier mobility error can be obtained (see, for example, Patent Document 3). However, in the printed organic thin film transistor described in Patent Document 3, after the organic semiconductor film is formed by printing, it is necessary to change the molecular structure by external stimulation such as heat, and thus there is a limitation in the process. Further, Patent Document 3 does not describe a limit voltage which is important as a performance of an organic thin film transistor.

Achieve performance with high carrier mobility and limit voltage The printed type with small error is TFT, which is indispensable for the application of the device.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-233724

Patent Document 2; Japanese Patent Laid-Open Publication No. 2008-066439

Patent Document 3: Japanese Laid-Open Patent Publication No. 2013-201363

The present invention has been made in view of the above problems, and an object thereof is to provide an organic thin film electrode having a high carrier mobility and a small error in performance such as a limit voltage. A crystal, an organic thin film transistor array using the organic thin film transistor, and an electronic device.

As a result of intensive studies to solve the above problems, the inventors have found that an organic thin film transistor having a high carrier mobility and a small error in performance such as a limit voltage can be formed to complete the present invention.

That is, the present invention relates to an organic thin film transistor which is an organic thin film transistor having a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor film, characterized in that the organic semiconductor film, In the organic semiconductor represented by the general formula (1), the interface energy between the material used for the gate insulating film and the organic semiconductor is 2.0 mJ/m ² or less, and the organic semiconductor film is formed by a printing process. And got:

In the formula, R ¹ to R ⁶ are each independently represented by a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and a carbon number of 1 to 20; Alkoxy group, alkylthio group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, ring of 3 to 12 member rings a heteroalkyl group, a heteroaryl group of 5 to 14 membered rings, or a group represented by the formula (2): [Chemical 2]-YR ⁷ (2)

In the formula, R ⁷ represents a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, a cycloheteroalkyl group having 3 to 12 member rings, or a heteroaryl group having 5 to 14 member rings, and a Y system. It represents a divalent alkyl group having 1 to 6 carbon atoms or a divalent halogenated alkyl group having 1 to 6 carbon atoms.

Furthermore, the present invention relates to an organic thin film transistor, which is characterized by The above printing process is selected from the printing process of dispensing printing, inkjet printing, offset printing, letterpress printing, gravure printing, gravure printing, slit coating printing or screen printing.

Further, the present invention relates to an organic thin film transistor array obtained by using the above organic thin film transistor, a differential amplification circuit, and an organic electronic device using the differential amplification circuit.

According to the present invention, it is possible to provide an organic thin film transistor having a high carrier mobility and a small error in performance such as a limit voltage. Further, by using the organic thin film transistor, it is possible to form an ideal printed organic thin film transistor array having a small output-input difference, in particular, a differential amplification circuit which exhibits an ideal input/output characteristic, and can be applied to various sensors.

(A) ‧‧‧Bottom gate-top contact organic thin film transistor

(B) ‧‧‧ bottom-bottom contact type organic thin film transistor

(C) ‧‧‧ First door contact organic thin film transistor

(D)‧‧‧The first door-bottom contact type organic thin film transistor

1‧‧‧Organic semiconductor layer

2‧‧‧Substrate

3‧‧‧gate electrode

4‧‧‧ gate insulation

5‧‧‧Source electrode

6‧‧‧汲electrode

Fig. 1 is a view showing the structure of a cross-sectional shape of an organic thin film transistor.

Fig. 2 is a diagram showing a transmission characteristic diagram.

Figure 3 is a diagram showing a histogram of mobility.

Fig. 4 is a view showing a histogram of the limit voltage.

Fig. 5 is a view showing a differential amplification circuit.

Fig. 6 is a diagram showing a transmission characteristic diagram.

Figure 7 is a diagram showing a histogram of mobility.

Figure 8 is a diagram showing a histogram of the limit voltage.

Figure 9 is a diagram showing a transmission characteristic diagram.

Figure 10 is a diagram showing a histogram of mobility.

Figure 11 is a diagram showing a histogram of the limit voltage.

Figure 12 is a diagram showing a transmission characteristic diagram.

Figure 13 is a diagram showing a histogram of mobility.

Figure 14 is a diagram showing a histogram of the limit voltage.

Used in the gate electrode of the organic thin film transistor of the present invention, and There is no particular limitation, and examples thereof include aluminum, gold, silver, copper, highly doped cerium, tin oxide, indium oxide, indium tin oxide, molybdenum oxide, chromium, titanium, cerium, chromium, graphene, and carbon nanotubes. An inorganic material such as an organic material doped with a conductive polymer (for example, PEDOT-PSS).

Gate used in the present invention, an organic thin film transistor a gate insulating film, the interface between the material of the line gate insulating film and the organic semiconductor energy of 2.0mJ / m ² or less, to 1.8mJ / m ² or less is preferable, and 0.001 to 1.5 mJ/m ^{2 is more} preferable. By allowing the interface to be in the above range, the organic semiconductor film formed on the surface of the gate insulating film can be uniformly crystallized (layered crystal), and the error in the performance of the limit voltage of the organic thin film transistor can be made small. .

In the present invention, the material used for the gate insulating film and the organic half The interface energy between the conductors can be calculated by the following formula (a).

γ ₁₂ =γ ₁ +γ ₂ -(γ ₁ ^d γ ₂ ^d ) ^1/2 -2(γ ₁ ^p γ ₂ ^p ) ^1/2 (a)

In the formula, γ ₁₂ represents the interfacial energy, γ ₁ is the surface energy of the material used for the gate insulating film, γ ₁ ^d is the dispersing force of the material using the gate insulating film, and γ ₁ ^p is used for the gate insulating film. polar component material, the surface of the organic semiconductor γ ₂ based energy, dispersion force γ ₂ ^d-based organic semiconductor, the polar component γ ₂ ^p type organic semiconductors. Further, these values were measured using a gate insulating film or an organic semiconductor material, and the contact angle of water and the contact angle of methyl iodide were measured by the θ/2 method and calculated by the method of Owens-Wendt.

The invention can be used for a material of a gate insulating film, and can be an evaporation type Material or coated material. Here, the "vapor deposition type material" means a material which can obtain a gate insulating film by vapor deposition, and the "coating type material" means a material which can obtain a gate insulating film by a coating. In general, the vapor deposition type material is difficult to obtain a coating process because the solubility of the substance before vapor deposition is low, and the coating type material is difficult to be vapor-deposited because the vapor pressure of the substance before vapor deposition is low.

According to the present invention, it can be coated by a gate insulating film. Since the organic thin film transistor is suitable for high productivity, the material used for the gate insulating film is preferably a coating type material. In addition, among the coating materials, the coating liquid after coating can be hardened by bridging operation, and it is suitable for manufacturing organic thin film transistors with higher productivity to use organic low molecules having bridging points or having bridging points. A coating material (organic coating type material) derived from an organic polymer is more preferable. Here, the bridging operation can carry out the organic low molecular molecule having the bridging point or the organic polymer having the bridging point after the coating, by heat or light treatment.

Further, in the present invention, when a vapor deposition type material is used, a vapor deposition type material (organic vapor deposition type material) obtained by vapor deposition of an organic low molecule is preferable because of the ease of film thickness control.

The material used for the gate insulating film is not particularly limited as long as the interface energy with the organic semiconductor is 2.0 mJ/m ² or less. Specifically, for example, an inorganic coating type material using a coating type inorganic oxide; a bridged polymethyl methacrylate type resin, a bridged polymethyl methacrylate type resin, and a bridged polyimide type resin ( A poly-proline which has a cyclization point as a precursor, a dehydration cyclization reaction of a proline acid group of a polyproline, a solvent-resistant bridging polyimide resin, and a bridged polycarbonate Ester resin, bridging poly(diisopropyl fumarate) resin, bridging poly(diethyl fumarate) resin, bridging polyethylene terephthalate resin, bridging polyethylene naphthalate Glycol ester-based resin, bridged polyether oxime resin, bridged cyclic polyolefin resin, bridged polystyrene resin, bridged poly-α-methylstyrene resin, bridged polyethylene resin, bridged polypropylene Resin, bridged poly(ethylene-propylene) copolymer resin, bridged poly(ethylene-norbornene) copolymer resin, BCB resin (pre-coating material: divinyl siloxane benzocyclobutene (BCB) )) organic coating type materials; use of vapor-deposited inorganic oxides Evaporation type material; poly(p-xylene) (pre-evaporation material: di-p-xylene), poly(chloro-p-xylene) (pre-evaporation material: dichloro-p-xylene), poly An organic vapor deposition type material such as (dichloro-p-xylene) (substance before vapor deposition: tetrachlorodi-p-xylene).

In the present invention, the coated material, due to the BCB resin, is The machine-coated material is particularly suitable for obtaining an organic thin film transistor having a smaller interface energy and a small error in performance. Further, the vapor-deposited material is particularly preferred because it is an organic vapor-deposited material because of poly(chloro-p-xylene), and is suitable for obtaining an organic thin film transistor having a smaller interface energy and a small error in performance.

When an organic coating type material is used for the gate insulating film, an example can be used. For example, it is coated with a solvent dissolved in chloroform, toluene, xylene, tetrahydrofuran, propylene glycol, propylene glycol-1-monomethyl ether-2-acetate, methyl ethyl ketone, methyl cyclohexanone or the like. The film of the layer serves as a gate insulating film.

In addition, the surface of the gate insulating film can also be used, for example, in ten Octachlorotrichloromethane, decyltrichlorodecane, decyltrimethoxydecane, octyltrichlorodecane, octadecyltrimethoxydecane, β-ethoxyphenyltrichlorodecane, β-ethoxybenzene A decane such as methoxy methoxy hexane, phenyl trichloro decane, phenyltrimethoxy decane or phenyltriethoxymethane or a decylamine such as hexamethyldiazepine or the like.

Generally, it is possible to perform surface treatment of the gate insulating film. The increase in the crystal grain size and the improvement of the molecular alignment of the material constituting the organic semiconductor film can improve the carrier mobility and the current opening/closing ratio, and a preferable result of lowering the limit voltage.

Source electrode and tantalum used in the organic thin film transistor of the present invention The material of the electrode electrode is not particularly limited, and the same material as that of the gate electrode can be used, and the material of the gate electrode can be the same or different, and the dissimilar materials can be laminated. In addition, in order to improve the implantation efficiency of the carriers, surface treatment may be performed on the electrode materials. The surface treatment agent for the electrode material may, for example, be phenylthiol or pentafluorobenzenethiol.

When the surface treatment of the electrode is performed, the surface treatment agent may be dissolved. The agent is diluted and used. The solvent to be diluted is not particularly limited, and examples thereof include alcohol solvents such as methanol, ethanol, and 2-propanol; o-dichlorobenzene, chlorobenzene, 1,2-dichloroethane, 1, 1, 2 , a halogen-based solvent such as 2-tetrachloroethane or chloroform; an ether system solvent such as THF (tetrahydrofuran) or dioxane; a hydrocarbon solvent of an aromatic compound such as toluene, xylene or trimethylbenzene; An ester solvent such as ethyl ester or γ-butyrolactone; a guanamine solvent such as N,N-dimethylformamide or N-methylpyrrolidone.

Organic semiconductor used in the organic thin film transistor of the present invention Membrane, which contains a specific organic semiconductor.

The organic semiconductor has a structure represented by the following formula (1):

In the formula (1), R ₁ to R ₆ each independently represent a hydrogen atom; methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butyl, isobutyl Base, n-pentyl, isopentyl, neopentyl, n-hexyl, n-butyl, n-octyl, etc., having a carbon number of 1 to 20, preferably 4 to 8 alkyl; vinyl, propenyl, butyl Alkenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl and the like have a carbon number of 2 to 20, preferably 4 to 8 internal or terminal alkenyl groups; ethynyl groups, a propynyl group, a butynyl group, a pentynyl group or the like having 2 to 20 carbon atoms, preferably 4 to 8 internal or terminal alkynyl groups; methoxy, ethoxy, n-propoxy, isopropoxy And the third butoxy group has a carbon number of 1 to 20, preferably 4 to 8 alkoxy group; methylthio group, ethylthio group, n-propylthio group, isopropylthio group, tert-butylthio group, etc. The alkyl group having a carbon number of 1 to 20 and 4 to 8 is preferred; trifluoromethyl, pentafluoroethyl, difluoromethyl, fluoromethyl, trichloromethyl, dichloromethyl, and chloroform. a carbon number of 1 to 20 having one or more halogen substituents such as a pentachloroethyl group, preferably a halogenated alkyl group of 4 to 8; a cyclopropyl group, a cyclopentyl group, and a ring; , cycloheptyl, cyclopentenyl, cyclohexenyl, cyclohexadienyl, cycloheptatrienyl, norbornyl, norbornyl, norbornyl, adamantyl, bicyclo[4 5] a cycloalkyl group having a carbon number of 3 to 10, such as a decyl group; a carbon number of 6 to 14 in the case of a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an anthryl group or a phenanthryl group, and 6 to 10 Jiazhi aryl; 3~12 member ring, 4~8 member ring is preferred cycloheteroalkyl group, 5~14 member ring, 5~8 member ring is preferred heteroaryl group, or general formula (2) An alkylaryl group represented by an alkyl-cycloalkyl group, a benzyl group or the like; an alkylcycloheteroalkyl group, an alkylheteroaryl group or the like: [Chemical 4]-YR ⁷ (2)

In the formula, R ⁷ represents a carbon number of 3 to 10, preferably 4 to 8 is a cycloalkyl group, a carbon number of 6 to 14, a 6 to 10 is preferably an aryl group, a 3 to 12 member ring, and a 4 to 8 member. The ring is preferably a cycloheteroalkyl group, or a 5- to 14-membered ring, a heteroaryl group having a 5- to 8-membered ring, and the Y-based group is a divalent alkyl group having a carbon number of 1 to 6, preferably 2 to 4. Or a divalent halogenated alkyl group having a carbon number of 1 to 6 and preferably 2 to 4.

Further, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aryl group having 6 to 14 carbon atoms may be used. a cycloalkylene group of a 3 to 12 membered ring, or a heteroaryl group of a 5 to 14 membered ring, 1 to 4 halogen atoms, a cyano group, a nitro group, an oxy group, a hydroxyl group, a NH ₂ group, and a carbon number of 1 to 20 Amine group, arylamino group having 6 to 14 carbon atoms, sulfonyl group, methionyl group, alkylcarbonyl group having 1 to 20 carbon atoms, arylcarbonyl group having 6 to 14 carbon atoms, carbonyl group, alkyl group having 1 to 20 carbon atoms Hydroxycarbonyl group, aryloxycarbonyl group having 6 to 14 carbon atoms, quinone imine group, alkyl quinone imine group having 1 to 20 carbon atoms, aryl fluorinylene group having 6 to 14 carbon atoms, thioresenimine group, carbon 1 to 20 alkylthioanilide groups, 6 to 14 carbon aryl sulfoximine groups, sulfonimide groups, alkyl 1 to 20 alkyl sulfonimide groups, carbon number 6 ~14 arylsulfonimide, fluorenyl, alkyl 1 to 20 alkyl, alkyl 1 to 20, 2 to 20 alkenyl, 2 to 20 alkyne Base, alkoxy group having 1 to 20 carbon atoms, alkylthio group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 20 carbon atoms, and aryl group having 6 to 14 carbon atoms Halogenated aryl, cycloalkylene of 3 to 12 membered rings and/or 5 to 14 membered rings A substituted aryl group.

The organic semiconductor represented by the formula (1) is excellent in solubility due to the structure represented by the formula (3), and an organic thin film transistor having a smaller error in performance such as a limit value can be obtained:

In the formula (3), R ¹ and R ² each independently represent a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a t-butyl group, an isobutyl group, and a positive group. The pentyl group, the isopentyl group, the neopentyl group, the n-hexyl group, the n-heptyl group, the n-octyl group and the like have a carbon number of 1 to 20, preferably 4 to 8 alkyl groups; methoxy group, ethoxy group, and n-propyl group. The oxy group, the isopropoxy group, the third butoxy group or the like has a carbon number of 1 to 20, preferably 4 to 8 or more, and is a more preferable structure of the present invention. In the formula (3), R ¹ and R ² each independently represent an alkyl group having a carbon number of 1 to 20 and preferably 4 to 8.

Specific examples of the organic semiconductor used in the present invention include 2,7- Di(n-methyl)dithienobenzodithiophene, 2,7-di(n-ethyl)dithienobenzodithiophene, 2,7-di(n-propyl)dithienobenzodithiophene, 2,7-di(isopropyl)dithienobenzodithiophene, 2,7-di(n-butyl)dithienobenzodithiophene, 2,7-di(t-butyl)dithiophene Benzodithiophene, 2,7-di(t-butyl)dithienobenzodithiophene, 2,7-di(isobutyl)dithienobenzodithiophene, 2,7-di(n-pentyl) Di) thienobenzodithiophene, 2,7-di(isopentyl)dithienobenzodithiophene, 2,7-di(neopentyl)dithienobenzodithiophene, 2,7- Two (n-hexyl) Dithienobenzodithiophene, 2,7-di(n-heptyl)dithienobenzodithiophene, 2,7-di(n-octyl)dithienobenzodithiophene, 2,7-di ( N-decyl)dithienobenzodithiophene, 2,7-di(n-dodecyl)dithienobenzodithiophene, 2,7-di(n-tetradecyl)dithienobenzodithiophene , 2,7-di(vinyl)dithienobenzodithiophene, 2,7-di(propylene)dithienobenzodithiophene, 2,7-di(butenyl)dithienobenzophenone Dithiophene, 2,7-di(pentenyl)dithiophenebenzodithiophene, 2,7-di(hexenyl)dithienobenzodithiophene, 2,7-di(butadienyl) Thienobenzodithiophene, 2,7-di(pentadienyl)dithienobenzodithiophene, 2,7-di(hexadienyl)dithienobenzodithiophene, 2,7-di (ethynyl)dithienobenzodithiophene, 2,7-di(propenyl)dithienobenzodithiophene, 2,7-di(butynyl)dithienobenzodithiophene, 2,7 - bis(pentynyl)dithienobenzodithiophene, 2,7-bis(methoxy)dithienobenzodithiophene, bis(methoxy)dithienobenzodithiophene, 2,7 - bis(n-propoxy)dithienobenzothiazide , 2,7-di (isopropoxy) bis thieno benzodithiophene, 2,7-bis (tert-butoxy) bis thieno benzodithiophene like.

An organic semiconductor film in the organic thin film transistor of the present invention, It is characterized in that it can be printed by a process film. By forming a film-forming organic semiconductor film by a printing process, it is possible to exhibit not only high productivity, but also an organic thin film transistor having a high carrier mobility and a small error in the limit voltage.

The organic semiconductor film can be printed, for example, by printing on the substrate It is produced by an organic semiconductor represented by the formula (1). At this time, after printing the solution of the organic semiconductor on the substrate, the solvent is vaporized by a method such as heating, gas flow, and/or natural drying to form an organic semiconductor film.

The solvent used to dissolve the organic semiconductor of the present invention is not particularly Do not limit. For example, a halogen-based solvent such as o-dichlorobenzene, chlorobenzene, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane or chloroform; THF, dioxane or the like; An ether solvent; a hydrocarbon solvent of an aromatic compound such as toluene, xylene or trimethylbenzene; an ester solvent such as ethyl acetate or γ-butyrolactone; N,N-dimethylformamide, N-A An amine solvent such as a pyrrolidone or the like may be used, and one or a mixture of two or more of these solvents may be used. Among them, chlorobenzene, toluene, trimethylbenzene, and tetralin are preferable because they have high solubility in the organic semiconductor used in the present invention and can be used in a general printing process.

The concentration of the organic semiconductor in the above solution is not particularly limited. The solubility of the organic semiconductor and the efficiency of the printing process are preferably 0.01 to 10.0% by weight, more preferably 0.05 to 7% by weight. The temperature at the time of printing is not particularly limited, and since it is not required to be used in the printing, it can be suitably carried out at 20 to 200 °C.

When the organic semiconductor film is fabricated by the present invention, the printing process has Printed or unprinted. Then, the printing process is not particularly limited as long as the solution of the organic semiconductor is applied to the substrate after the organic semiconductor film is formed, and the process is high in productivity and easy to form a pattern to be dispensed. Inkjet printing, offset printing, letterpress printing, gravure printing, gravure printing, slit coating printing, or screen printing are preferred.

Among them, in terms of mass productivity and precision, it is more preferable to use offset printing, inkjet printing, offset printing, letterpress printing, or slit coating printing.

With gate electrode, gate insulating film, source electrode, and bungee The structure of the electrode and the organic thin film transistor having an organic semiconductor film may be, for example, the cross-sectional structure shown in Fig. 1.

In Fig. 1, it can be classified into (A) bottom gate-top contact type, (B) bottom gate-bottom contact type, (C) top gate-top contact type, and (D) top gate-bottom contact. The organic thin film transistor of the type shown in Fig. 1 shows an organic semiconductor layer, a 2-system substrate, a 3-system gate electrode, a 4-system gate insulating film, a 5-series source electrode, and a 6-system drain electrode.

A specific example of a substrate that can be used for an organic thin film transistor can be mentioned For example, polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polymethyl acrylate, polyethylene, polypropylene, polystyrene, cyclic polyolefin, fluorination Cyclic polyolefin, polyimine, polycarbonate, polyvinyl phenol, polyvinyl alcohol, poly (diisopropyl fumarate), poly (diethyl fumarate), poly (maleic acid diiso) Plastic substrates such as propyl ester, polyether oxime, polyphenylene sulfide, and cellulose triacetate; glass, quartz, alumina, tantalum, highly doped cerium, lanthanum oxide, cerium oxide, antimony pentoxide, indium tin oxide An inorganic material substrate such as a material; a metal substrate such as gold, copper, chromium, titanium, or aluminum.

Furthermore, when a highly doped germanium is used for the substrate, the substrate can also serve as the gate electrode of the present invention.

The material of the substrate to be used is not particularly limited, and crystallization can be used. Sexual, non-crystalline materials. Specific examples of the substrate include polyethylene terephthalate, polymethyl methacrylate, polyethylene, polypropylene, polystyrene, cyclic polyolefin, polyimine, polycarbonate, and the like. Plastic substrate of polyvinylphenol, polyvinyl alcohol, poly(diisopropyl fumarate), poly(diethyl fumarate), poly(diisopropyl maleate), glass, quartz, alumina An inorganic material substrate such as ruthenium, osmium oxide, ruthenium dioxide, ruthenium pentoxide or indium tin oxide; or a metal substrate such as gold, copper, chromium or titanium. Further, for example, a decane such as octadecyltrichlorodecane or octadecyltrimethoxydecane may be used as the surface of the substrate; A mercaptoamine modification processor such as hexamethyldiazepine. Furthermore, the substrate can also be an insulating or dielectric material. The solvent after printing can be removed by drying under normal pressure or reduced pressure, or can be removed by heating or drying with a nitrogen stream.

Generally, the limit voltage of the transistor used in the circuit can be confirmed incorrectly. When the difference is made, the operation of the circuit becomes unstable and it is difficult to obtain the desired circuit characteristics. In addition, generally, the desired circuit characteristics are stably obtained, and the standard deviation σ of the error value of the limit voltage of the transistor is used as an index to perform circuit design, and stable circuit characteristics can be obtained even at 3σ, so that the limit voltage is desired. A transistor with a small standard deviation σ. Since the organic thin film transistor of the present invention is characterized by a small error in the limit voltage, the organic thin film transistor of the present invention can be used in a circuit to form a circuit that exhibits stable operation.

The limit of the organic thin film transistor of the present invention is generally It is known that the method for determining the limit value of the organic transistor can be obtained by any method. For example, the X-axis of the straight line obtained by plotting the square root of the saturation current to the gate voltage can be obtained from the transmission characteristic diagram of the organic transistor. The intercept is obtained.

The organic thin film transistor of the present invention is characterized in that the carrier mobility is high, and in order to obtain an organic electronic device having good performance, the mobility is preferably in the range of 0.001 to 100 cm ² /Vs.

The organic thin film transistor is a good organic electronic device, and the current switching ratio is more than 10 ⁵ or more, that is, the common logarithmic value of the current switching ratio (hereinafter, the common logarithmic value of the current switching ratio is referred to as "log10AR") is 5 or more. It is better.

The organic thin film transistor of the present invention is characterized by a limit voltage The error is small, and in addition, it is characterized in that when a plurality of components are arranged to fabricate an organic thin film transistor array, the standard deviation of the limit voltage of the organic thin film transistor array is The difference σ will become smaller. Then, since a small change in voltage is used for the organic electronic device, for example, when 100 or more elements are arranged to form an organic thin film transistor array, the standard deviation σ of the limit voltage of the organic thin film transistor array is 0.25 or less. Preferably, it is preferably 0.2 or less, and particularly preferably 0.1 or less.

The error of carrier mobility of the organic thin film transistor of the invention is small In addition, when a plurality of elements are arranged to form an organic thin film transistor array, a coefficient of variation of carrier mobility of the organic thin film transistor array is CV=|standard deviation σ/average| (hereinafter, referred to as "variation coefficient" CV (carrier mobility)") is small. Then, in order to stably produce an organic thin film transistor array, for example, when an organic thin film transistor array is formed by disposing 100 or more elements, the coefficient of variation CV (carrier mobility) is preferably 25% or less, and particularly 20% or less. good.

The error of the organic thin film transistor of the invention and the current switching ratio is small In addition, when a plurality of elements are arranged to form an organic thin film transistor array, the variation coefficient of log10AR of the organic thin film transistor array CV=|log 10AR is the average value of the standard deviation σ/log 10AR| (hereinafter, referred to as "variation" The coefficient CV (log10AR)") is small. Then, in order to stably produce an organic thin film transistor array, for example, when an organic thin film transistor array is formed by disposing 100 or more elements, the coefficient of variation CV (log 10 AR) is preferably 20% or less, and particularly preferably 15% or less. 10% or less is the best.

When an organic thin film transistor is used to form a differential amplifying circuit, for a higher sensing sensitivity, an increase of 1 to 1000 is preferred.

Example

The invention will be more specifically described by the following examples, but the invention should not be construed as limited.

Synthesis example Synthesis of (1,4-bis(3-bromothiophene)-2,5-difluorobenzene)

To a 100 ml Schlenk reaction vessel, 4.5 ml (3.6 mmol) of THF solution of isopropylmagnesium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 ml of THF were placed in a 100 ml Schlenk reaction vessel. The mixture was cooled to -75 ° C, and 873 mg (3.61 mmol) of 2,3-dibromothiophene (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise. After aging at -75 ° C for 30 minutes, 3.6 ml (3.6 mmol) of a solution of zinc chloride (1.0 mol/l, manufactured by Sigma Oric) was added dropwise. After slowly raising the temperature to room temperature, it was concentrated under reduced pressure to give a white syrup liquid, and 10 ml of light boiling fraction was distilled off.

Add 1,4- to the obtained white slurry (3-bromothiophene-2-zinc chloride) 272 mg (1.00 mmol) of dibromo-2,5-difluorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.), tetrakis(triphenylphosphine)palladium (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, 39.1 mg (0.0338 mmol, for 1) , 4-dibromo-2,5-difluorobenzene 3.38 mol%) and THF 10 ml. After the reaction was carried out at 60 ° C for 8 hours, the vessel was cooled with water, and 3 ml of 3N hydrochloric acid was added to terminate the reaction. The organic phase was washed with brine and dried over anhydrous sodium sulfate. The residue was concentrated under reduced pressure, and purified (yield from hexane to hexane/dichloromethane = 10/1). 227 mg (yield 52%) of pale yellow solid of (3-bromothiophene)-2,5-difluorobenzene.

¹ H-NMR (CDCl ₃ , 21 ° C): δ = 7.44 (d, J = 5.4 Hz, 2H), 7.39 (t, J = 7, 8 Hz, 2H), 7.11 (d, J = 5.4 Hz, 2H) .

MS m/z: 436 (M ⁺ , 100%), 276 (M ⁺ -2Br, 13).

(Synthesis of dithienobenzodithiophene)

Add in a 100 ml Schlenk reaction vessel under a nitrogen atmosphere 1,4-bis(3-bromothiophene)-2,5-difluorobenzene 200 mg (0.458 mmol), NMP 10 ml, and sodium sulfide 9 water (manufactured by Wako Pure Chemical Industries, Ltd.) 240 mg (1.00 mmol). The resulting mixture was heated at 170 ° C for 6 hours, and the resulting reaction mixture was cooled to room temperature. After adding toluene and water, the phases were separated, and the organic phase was washed twice with water and dried over anhydrous sodium sulfate. After concentrating under reduced pressure, the obtained residue was washed twice with hexane to give a pale yellow solid (yield 69%) of dithienobenzothiophene.

¹ H-NMR (CDCl ₃ , 60 ° C): δ = 8.28 (s, 2H), 7.51 (d, J = 5.2 Hz, 2H), 7.30 (d, J = 5.2 Hz, 2H).

MS m/z: 302 ( ^M+ , 100%), 270 ( ^M+ -S, 5), 151 ( ^M+ /2, 10).

(2,7-di(n-hexyl)dithienobenzodithiophene)

To a 100 ml Schlenk reaction vessel was added 86.8 mg (0.286 mmol) of dithienobenzodithiophene and 14 ml of dichloromethane. The mixture was ice-cooled, and 134 mg (1.00 mmol) of aluminum chloride (manufactured by Wako Pure Chemical Industries, Ltd.) and hexane chloride (manufactured by Wako Pure Chemical Industries, Ltd.) of 115 mg (0.858 mmol) were added. After the resulting mixture was stirred at room temperature for 30 hours, the reaction was stopped by ice-cooling and water. To the resulting slurry mixture, toluene was added to separate the phases. The organic phase of the yellow slurry was washed with water and concentrated under reduced pressure. The obtained residue was washed with hexane and methanol, and dried under reduced pressure to give 99.8 mg (yield: 70%) of the crude solid of di-n-hexyldithiophenebenzodithiophene.

¹ H-NMR (heavy benzene, 80 ° C): δ = 7.73 (s, 2H), 7.26 (s, 2H), 2.58 (t, J = 7.2 Hz, 4H), 1.71 (m, 4H), 1.28 (m) , 8H), 0.86 (t, J = 7.0 Hz, 6H).

MS m/z: 498 ( ^M+ , 100%), 442 ( ^M+ - C ₄ H ₉ +1, 46), 427 ( ^M+ - C ₅ H ₁₁ , 13).

Synthesis of (2,7-(di-n-hexyl)dithienobenzodithiophene)

To a 50 ml Schlenk reaction vessel, 50 mg (0.1 mmol) of di-n-hexyldithiophenebenzodithiophene, 5 mL of THF, and aluminum chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 69 mg (0.52 mmol) were added under ice cooling. After slowly adding 38 mg (1.00 mmol) of sodium borohydride, the mixture was heated under reflux for 4 hours. After cooling to room temperature, the reaction was stopped by adding water, toluene was added to the obtained slurry mixture, and toluene was mixed with water, and the organic opposite water was washed three times. The organic phase was dried over anhydrous sodium sulfate and evaporated. The obtained residue was separated and purified by a color column chromatography (hexane to hexane/toluene = 10/1), and further purified by hexane (purified by Wako Pure Chemical Industries, Ltd.) three times to obtain 2,7-two. 28 mg (0.059 mmol) of a white solid of (n-hexyl)dithienobenzodithiophene (yield 59%).

¹ H-NMR (CDCls): δ = 8.17 (s, 2H), 7.00 (s, 2H), 2.97 (t, J = 7.2 Hz, 4H), 1.78 (m, 4H), 1.28 (m, 12H), 0.88 (t, J = 7.0 Hz, 6H).

MS m/z: 470 (M ⁺ , 100%), 399 (M ⁺ - C ₅ H ₁₁ , 57), 328 (M ⁺ -2C ₅ H ₁₁ , 47).

Melting point: 190.2~190.4 °C.

Example 1 (soft substrate)

Polyethylene naphthalate (Teonex, manufactured by Teijin DuPont Film Co., Ltd.) having a thickness of 125 μm was used as a flexible substrate.

(formation of surface smoothing layer)

In a glove box, a 10 mL sample tube was charged with polyvinyl phenol (Mw-25000, Sigma, Inc., Mw-25000), 0.5 g, and propylene glycol-1-monomethyl ether-2-acetate (manufactured by Kanto Chemical Co., Ltd., Rot). 4.5 g, 2 g of the solution obtained by stirring for 10 hours, and adding poly(melamine-co-formaldehyde) to a 10 mL sample tube in a glove box (Sig Mn~432), 0.5 g, and propylene glycol-1-monomethyl ether-2-acetate (manufactured by Kanto Chemical Co., Ltd., Rote grade) 4.5 g, 2 g of the solution obtained by stirring for 10 hours, mixed 0.5 ml of the solution was spin-coated on a soft substrate (MS-A100M, manufactured by MIKASA Co., Ltd.) to form a film (1500 rpm), and then formed into a film thickness by heat treatment at 150 ° C for 60 minutes. A surface smoothing layer of 100 nm bridged polyvinylphenol.

(formation of gate electrode)

The surface smoothing layer formed above was treated with an oxygen plasma surface treatment apparatus (manufactured by SAMCO Co., Ltd., plasma dry cleaning machine PC-300) with oxygen plasma (100 W, 1 minute), and then a silver nanoparticle aqueous ink solution was applied. (JAGLT-01, manufactured by DIC Corporation), using an inkjet device with a 10pL clip (made by Fujifilm Dimatix Co., Ltd., DMP-2831, stage temperature 30 °C), and dripping at 60 μm intervals in the test chamber (Espec Corporation) After drying for 30 minutes in H-221, temperature 30 ° C, humidity 95% RH), a gate electrode having a thickness of 100 nm and a line width of 400 μm was formed by firing at 140 ° C for 60 minutes. Here, the gate electrode is formed, and the plastic substrate on which the gate insulating film is not formed is referred to as "a plastic substrate with a gate electrode."

(Formation of gate insulating film)

0.9 g of dichlorodi-p-xylene (trade name: dix-C) (manufactured by Daisei Co., Ltd.) was vacuum-deposited on a plastic substrate with a gate electrode by Labcoater (PDS2010, manufactured by PARYLENE JAPAN Co., Ltd.) to form a thickness. A gate insulating film of 550 nm poly(chloro-p-xylene).

(Source. Formation of the bungee electrode)

On the gate insulating film, silver nanoparticle ink (NPS-JL, manufactured by Halima Chemical Co., Ltd.) was used as an inkjet device (made by Fujifilm Dimatix Co., Ltd.). DMP-2831, stage temperature 50 ° C) was drawn at intervals of 60 μm, and then fired at 120 ° C × 60 minutes to form a channel with a channel length of 91 μm and a channel width of 1100 μm. Bottom electrode. Here, the gate electrode, the gate insulating film and the source will be formed. The plastic substrate of the drain electrode is referred to as "the electrode forms a plastic substrate with a gate insulating film."

(source. bungee electrode modification)

The electrode was formed into a plastic substrate with a gate insulating film and immersed in a solution (5 mM) of mixed pentafluorobenzenethiol (manufactured by Sigma-Olympus) and 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) for 3 minutes. , by drying the source. Modification of the electrode of the drain.

(formation of barrier layer)

The above-mentioned electrode was formed to have a plastic substrate with a gate insulating film held at 30 ° C, and the trade name was used thereon; Teflon (AF1600 manufactured by DuPont) was used as a dispensing device (manufactured by Musashi Engineering Co., Ltd., and the drawing speed was 20 mm/s). After the drawing pressure was 7 kPa and the nozzle temperature was 30 ° C), it was dried in the atmosphere for 10 minutes to form a frame surrounding source having a thickness of 200 nm, a line width of 300 μm, and an inner diameter of 1.1 mm × 2.5 mm. The barrier layer of the drain electrode.

(Formation of Organic Semiconductor Layer and Fabrication of Organic Thin Film Transistor)

To a 10 ml sample tube, 30 g of toluene and 30 mg of 2,7-di(n-hexyl)dithienobenzodithiophene were added to a 10 ml sample tube, and the mixture was dissolved at 50 ° C to prepare an organic semiconductor layer-forming solution (concentration: 1.0). (% by mass), using a dispensing printing apparatus (manufactured by Musashi Engineering Co., Ltd., drawing speed: 20 mm/s, injection pressure: 1 kPa, nozzle temperature: 30 ° C), and dropping in the above-prepared barrier layer (held at 30 ° C), and drying was carried out. An organic semiconductor layer is used to fabricate a bottom gate-bottom contact type organic thin film transistor.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to poly(chloro-p-xylene) and the contact angle of diiodomethane Can be 1.2mJ/m ² .

(semiconductor. electrical measurement)

Using a semiconductor parameter analyzer (Keithley Corporation, 4200-SCS), the electrical properties of the organic thin film transistor to drain voltage (V _d = -20V), the gate voltage (Vg) of +10 to - The 20V was scanned at a scale of 0.5V to evaluate the physical properties of the transmission. The carrier mobility was 1.9 cm ² /Vs, the limit voltage was -0.16 V, and the current switching ratio was 2.9 × 10 ⁸ .

Example 2

An organic thin film transistor was produced in the same manner as in Example 1, and the organic thin film transistor was placed in 100 elements to fabricate an organic thin film transistor array.

(Measurement of semiconductor electrical properties)

The obtained organic thin film transistor array was subjected to electrical measurement in the same manner as in Example 1. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio were calculated by the coefficient of variation CV, and the degree of error of the limit voltage was calculated by the standard deviation σ. As a result, 100 of the 100 elements of the fabricated organic thin film transistor array can be acted as a transistor, and the average carrier mobility of the 100 elements of the operation is 1.1 cm ² /Vs, and the standard deviation of the carrier mobility. Since σ is 0.17, the coefficient of variation CV (carrier mobility) is 15%. Further, the average of the common logarithm of the current switching ratio of 100 elements was 8.0, and the standard deviation σ of the common logarithm of the current switching ratio was 0.38, so the coefficient of variation CV (log10AR) was 5%. Further, the average value of the limit voltage is -0.011 V, and the standard deviation σ of the limit voltage is 0.086.

Figure 2 shows the transmission characteristics of the resulting 100 components, in the third chart. A histogram showing the mobility of the obtained 100 elements, and a histogram of the limit voltages of the obtained 100 elements is shown in FIG.

From the above, it was confirmed that very small error characteristics were exhibited.

Example 3

A differential amplification circuit was fabricated using an organic thin film transistor produced in the same manner as in Example 1. The differential amplification circuit produced is shown in Fig. 5.

(Measurement of semiconductor electrical properties)

Using a semiconductor parameter analyzer (4200-SCS, manufactured by Keithley, Inc.), the constant current source (I _DD ) was set to 500 nA, and the measurement was fixed at an arbitrary value of 6 V to 20 V with respect to the input voltage B (V _INB ). Voltage A (V _INA ) is the result of the output voltages V _OUTA and V _OUTB when scanning at 0V~30V. When the input voltage difference is 0V, the input-output voltage difference is 0V, which is an ideal input-output characteristic with an increase of 3.5. The differential amplification circuit shows the appropriate drive.

Example 4 (Formation of gate insulating film)

In a glove box, a solution obtained by mixing 3.0 g of divinyloxane benzocyclobutene (BCB) (trade name: CYCROTEN 3022-35) (manufactured by Dow Chemical Co., Ltd.) and 3.0 g of trimethylbenzene was used. 0.5 ml was spin-coated (500 rpm/5 sec and 2000 rpm/60 sec) on a plastic substrate with a gate electrode by a spin coater (MS-A100M, manufactured by MIKASA Co., Ltd.), further at 80 ° C for 3 minutes. In the same manner as in Example 1, a BBB resin having a film thickness of 525 nm obtained by heat treatment at 250 ° C for 60 minutes was used as a gate insulating film at 150 ° C × 3 minutes, 210 ° C × 40 minutes, and heat treatment at 250 ° C × 60 minutes. A pole-bottom contact type organic thin film transistor.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to BCB resin and the contact angle of diiodomethane are 0.35 mJ/m. ² .

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and electrical measurement of the organic thin film transistor array was performed. The carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio were calculated by the coefficient of variation CV, and the error degree of the limit voltage was calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.85 cm/Vs, and the standard deviation σ of the carrier mobility was 0.15, so the coefficient of variation CV (carrier mobility) was 18%. Further, the average of the common logarithm of the current switching ratio of 100 elements is 7.2 and the standard deviation σ of the common logarithm of the current switching ratio is 0.45, so the coefficient of variation CV (log10AR) is 6%. Further, the average value of the limit voltage is -1.5 V, and the standard deviation σ of the limit voltage is 0.093.

From the above, it was confirmed that very small error characteristics were exhibited.

Example 5 (Formation of gate insulating film)

In a glove box, a solution of a poly-proline (a precursor of a bridging polyimide resin) having a cyclization point (trade name: CT4112) (manufactured by Kyocera Chemical Co., Ltd.) (0.5 ml) was used, and a spin coater (MIKASA) was used. Company-made, MS-A100M), spin coating (500 rpm/5 sec and 6000 rpm/120 sec) on a plastic substrate with a gate electrode, further at 80 ° C × 60 minutes, 120 ° C × 60 minutes, and 180 A bottom gate-bottom was produced in the same manner as in Example 1 except that a bridged polyimine-based resin having a film thickness of 590 nm was obtained as a gate insulating film by heat treatment at ° C × 60 minutes. Contact type organic thin film transistor.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to the bridging polyimine resin and the contact angle of diiodomethane energy of 1.6mmJ / m ^2.

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. As a result, the average carrier mobility of the 100 elements produced was 0.55 cm ² /Vs, and the carrier was used. The standard deviation σ of the mobility was 0.051, so the coefficient of variation CV (carrier mobility) was 9%. Further, the average of the common logarithm of the current switching ratio of 100 elements is 6.4 and the standard deviation σ of the common logarithm of the current switching ratio is 0.51, so the coefficient of variation CV (log10AR) is 8%. Further, the average value of the limit voltage is 5.8 V, and the standard deviation σ of the limit voltage is 0.19.

From the above, it was confirmed that very small error characteristics were exhibited.

Example 6 (Formation of gate insulating film)

In the glove box, a solution of a poly-proline (a precursor of a bridging polyimide resin) having a cyclization point (trade name: CT4200) (manufactured by Kyocera Chemical Co., Ltd.) 3.0 g of mixed N-methyl 2-pyrrolidone 3.0 g of the obtained solution was spin-coated (500 rpm/5 sec and 2500 rpm/120 sec) on a plastic substrate with a gate electrode using a spin coater (MS-A100M, manufactured by MIKASA Co., Ltd.) using 0.5 ml of the solution. A bridged polyimide resin having a film thickness of 490 nm was obtained as a gate insulating film by heat treatment at 150 ° C × 60 minutes, 250 ° C × 30 minutes, and 320 ° C × 30 minutes. A bottom gate-bottom contact type organic thin film transistor was produced in the same manner as in Example 1.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to the bridging polyimine resin and the contact angle of diiodomethane energy of 1.7mJ / m ^2.

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio were calculated by the coefficient of variation CV, and the degree of error of the limit voltage was calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.42 cm ² /Vs, and the standard deviation σ of the carrier mobility was 0.087, so the coefficient of variation CV (carrier mobility) was 20%. Further, the average of the common logarithm of the current switching ratio of 100 elements is 3.1 and the standard deviation σ of the common logarithm of the current switching ratio is 0.31, so the coefficient of variation CV (log10AR) is 10%. Further, the average value of the limit voltage is 6.2 V, and the standard deviation σ of the limit voltage is 0.19.

From the above, it was confirmed that very small error characteristics were exhibited.

Example 7 (Formation of gate insulating film)

2.7 g of di-p-dimethylphenyl (trade name: dix-N) (manufactured by Daisei Co., Ltd.), vacuum-deposited 431 nm on a plastic substrate with a gate electrode by LABCOATER (PDS2010, manufactured by PARYLENE JAPAN) The bottom gate-bottom was fabricated in the same manner as in Example 1 except that poly(p-xylene) was used as the gate insulating film. Contact type organic thin film transistor.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to the bridging polyimine resin and the contact angle of diiodomethane Can be 1.5mJ/m ² .

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio were calculated by the coefficient of variation CV, and the degree of error of the limit voltage was calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.75 cm ² /Vs, and the standard deviation σ of the carrier mobility was 0.072, so the coefficient of variation CV (carrier mobility) was 9%. Further, the average of the common logarithm of the current switching ratio of 100 elements was 6.8, and the standard deviation σ of the common logarithm of the current switching ratio was 0.53, so the coefficient of variation CV (log10AR) was 8%. Further, the average value of the limit voltage was -0.052 V, and the standard deviation σ of the limit voltage was 0.18.

From the above, it was confirmed that very small error characteristics were exhibited.

Comparative example 1 (Formation of Organic Semiconductor Layer and Fabrication of Organic Thin Film Transistor)

In the case of forming an organic semiconductor layer, a bottom gate-bottom contact type organic thin film transistor was produced in the same manner as in Example 1 except that a 0.2 wt% toluene solution was used and a dropping casting method (dropping 0.5 μL) was used.

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio are calculated by the coefficient of variation CV, and the error degree of the limit voltage is calculated by the standard deviation σ. As a result, the average carrier elements 100 fabricated mobility was 0.37cm ² / Vs, and a standard deviation σ of the carrier mobility of 0.13, so that the coefficient of variation CV (carrier mobility) was 35%. Further, the average logarithm of the current switching ratio of the 100 elements was 7.3 and the standard deviation σ of the common logarithm of the current switching ratio was 0.48, so the coefficient of variation CV (log 10AR) was 7%. Further, the average value of the limit voltage is -0.21 V, and the standard deviation σ of the limit voltage is 0.29.

Fig. 6 is a graph showing the transmission characteristics of the obtained 100 elements, Fig. 7 is a histogram showing the transition rates of the obtained 100 elements, and Fig. 8 is a histogram showing the limit voltages of the obtained 100 elements.

An organic thin film transistor produced by a dropping casting method which is not a printing process is used, and an organic thin film transistor having a small error characteristic cannot be obtained.

Comparative example 2 (Formation of Organic Semiconductor Layer and Fabrication of Organic Thin Film Transistor)

2,8-difluoro-5,11-bis(triethyldecylethynyl)phosphonium dithiophene (manufactured by Sigma Oricic Co., Ltd.) was used as the organic semiconductor (solute), and the solvent was used in the presence of trimethylbenzene. A bottom gate-bottom contact type organic thin film transistor was produced in the same manner as in Example 1.

(calculation of interface energy)

The contact angle of water to 2,8-difluoro-5,11-bis(triethyldecylethynyl)phosphonium dithiophene and the contact angle of diiodomethane, and the contact of water with poly(chloro-p-xylene) The interface energy of the angle of contact of the angle and diiodomethane was 0.79 mJ/m ² .

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio are calculated by the coefficient of variation CV, and the error degree of the limit voltage is calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.10 cm ² /Vs, and the standard deviation σ of the carrier mobility was 0.030, so the coefficient of variation CV (carrier mobility) was 30%. Further, the average of the common logarithm of the current switching ratio of 100 elements was 7.0 and the standard deviation σ of the common logarithm of the current switching ratio was 0.76, so the coefficient of variation CV (log10AR) was 11%. Further, the average value of the limit voltage was 0.85 V, and the standard deviation σ of the limit voltage was 0.35.

Fig. 9 is a graph showing the transmission characteristics of the obtained 100 elements, and Fig. 10 is a histogram showing the mobility of the obtained 100 elements, and Fig. 11 is a histogram showing the limit voltages of the obtained 100 elements.

Since the organic semiconductor film does not contain the organic semiconductor represented by the general formula (1), an organic thin film transistor having a small error characteristic cannot be obtained.

Comparative example 3 (Formation of Organic Semiconductor Layer and Fabrication of Organic Thin Film Transistor)

2,8-difluoro-5,11-bis(triethyldecylethynyl)phosphonium dithiophene (manufactured by Sigma Oricic Co., Ltd.) was used as an organic semiconductor (solute), and 0.2 wt% was prepared using trimethylbenzene as a solvent. When the solution was formed and the organic semiconductor layer was formed, the bottom gate-bottom contact organic compound was produced in the same manner as in Example 1 except that the 0.2 wt% trimethylbenzene solution was used and the dropping casting method (dropping 0.5 μL) was used. Thin film transistor.

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio are calculated by the coefficient of variation CV, and the error degree of the limit voltage is calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.10 cm ² /Vs, and the standard deviation σ of the carrier mobility was 0.060, so the coefficient of variation CV (carrier mobility) was 60%. Further, the average logarithm of the current switching ratio of the 100 elements was 3.8 and the standard deviation σ of the common logarithm of the current switching ratio was 1.5, so the coefficient of variation CV (log10AR) was 39%. Further, the average value of the limit voltage was 0.22 V, and the standard deviation σ of the limit voltage was 0.68.

Fig. 12 is a graph showing the transmission characteristics of the obtained 100 elements, and Fig. 13 is a histogram showing the mobility of the obtained 100 elements, and Fig. 14 is a histogram showing the limit voltages of the obtained 100 elements.

Since the organic semiconductor film does not contain the organic semiconductor represented by the general formula (1), and the organic thin film transistor is formed by a dropping casting method which is not a printing process, an organic thin film transistor having a small error characteristic cannot be obtained.

Comparative example 4 (Formation of gate insulating film)

In a glove box, 1.0 g of polyvinylphenol (Mw~25000, manufactured by Sigma Oric, Inc.) and propylene glycol-1-monomethyl ether-2-acetate (manufactured by Kanto Chemical Co., Ltd., Rote grade) were added to a 10 mL sample tube. 4.0 g, 1 g of the solution obtained by stirring for 10 hours, and a poly (melamine-co-formaldehyde) (manufactured by Sigma-Rickey Co., Ltd., Mn~432) 0.5 g and propylene glycol-1-1 were added to a 10 mL sample tube in a glove box. Monomethyl ether-2-acetate (manufactured by Kanto Chemical Co., Ltd., Lut grade) 4.5 g, obtained by stirring for 10 hours 2 g, 0.5 ml of the obtained solution was mixed, and spin-coated on a soft substrate (MS-A100M, manufactured by MIKASA Co., Ltd.) on the above-mentioned flexible substrate (500 rpm/5 sec, and 1500 rpm/30 sec) Thereafter, a bridged polyethylene phenol having a film thickness of 535 nm was formed as a heat insulating film at 90 ° C for 10 minutes and at 150 ° C for 60 minutes, and a bottom gate-bottom contact organic compound was produced in the same manner as in Example 1. Thin film transistor.

(calculation of interface energy)

The contact angle of water to 2,7-(n-hexyl)dithienobenzodithiophene and the contact angle of diiodomethane, and the contact angle of water to bridging polyvinylphenol and the contact angle of diiodomethane were calculated to be 3.9. mJ/m ² .

(Measurement of semiconductor electrical properties)

An organic thin film transistor array was produced in the same manner as in Example 2, and the electrical properties of the organic thin film transistor array were measured. Then, the carrier mobility of the 100 organic thin film transistor elements and the error degree of the current switching ratio are calculated by the coefficient of variation CV, and the error degree of the limit voltage is calculated by the standard deviation σ. As a result, the average carrier mobility of the produced 100 elements was 0.32 cm ² /Vs, and the standard deviation σ of the carrier mobility was 0.037, so the coefficient of variation CV (carrier mobility) was 11%. Further, the average of the common logarithm of the current switching ratio of the 100 elements was 4.2 and the standard deviation σ of the common logarithm of the current switching ratio was 0.87, so the coefficient of variation CV (log10AR) was 21%. Further, the average value of the limit voltage was -2.7 V, and the standard deviation σ of the limit voltage was 0.67.

Since the interface energy between the material for the gate insulating film and the organic semiconductor is larger than ² mJ/m ² , an organic thin film transistor having a small error characteristic cannot be obtained.

Industrial profitability

The organic thin film transistor of the present invention can effectively utilize various characteristics such as a semiconductor pH sensor, a semiconductor ion sensor, a semiconductor pressure sensor, a semiconductor temperature sensor, and an optical sensor, because of high mobility and low error in performance such as a limit voltage. High sensitivity sensor.

Furthermore, the present invention claims priority to Japanese Patent Application No. 2014-036940, the filing date of which is the entire filing date of .

Claims (9)

An organic thin film transistor having an organic thin film transistor having a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor film, wherein the organic semiconductor film is represented by the general formula (1) The organic semiconductor has an interface energy of 2.0 mJ/m ² or less between the material of the gate insulating film and the organic semiconductor, and the organic semiconductor film is formed by a printing process: In the formula, R ¹ to R ⁶ are each independently represented by a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and a carbon number of 1 to 20; Alkoxy group, alkylthio group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, ring of 3 to 12 member rings a heteroalkyl group, a heteroaryl group of 5 to 14 membered rings, or a group represented by the formula (2): -YR ⁷ (2) wherein R ⁷ represents a cycloalkyl group having 3 to 10 carbon atoms and a carbon number 6 to 14 aryl, 3 to 12 membered ring heteroalkyl, or 5 to 14 membered heteroaryl, Y is a carbon number of 1 to 6 divalent alkyl, or a carbon number of 1 to 6. A divalent halogenated alkyl group. The organic thin film transistor according to the first aspect of the patent application, wherein the material used for the gate insulating film is an organic coating type material. An organic thin film transistor having an organic thin film transistor having a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor film, wherein the organic semiconductor film is represented by the general formula (1) The organic semiconductor is used for the material of the gate insulating film (chloro-p-xylene), and the organic semiconductor film is formed by a printing process: In the formula, R ¹ to R ⁶ are each independently represented by a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and a carbon number of 1 to 20; Alkoxy group, alkylthio group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, ring of 3 to 12 member rings a heteroalkyl group, a heteroaryl group of 5 to 14 membered rings, or a group represented by the formula (2): -YR ⁷ (2) wherein R ⁷ represents a cycloalkyl group having 3 to 10 carbon atoms and a carbon number 6 to 14 aryl, 3 to 12 membered ring heteroalkyl, or 5 to 14 membered heteroaryl, Y is a carbon number of 1 to 6 divalent alkyl, or a carbon number of 1 to 6. A divalent halogenated alkyl group. The organic thin film transistor according to claim 1, wherein the material used for the gate insulating film is poly(p-xylene) or poly(dichloro-p-xylene). The organic thin film transistor according to any one of claims 1 to 4, wherein the organic semiconductor is represented by the general formula (3): In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms. The organic thin film transistor according to any one of claims 1 to 5, wherein the printing process of the organic semiconductor film is dispensing printing, inkjet printing, offset printing, letterpress printing, gravure printing, gravure printing, slit Coat printing or screen printing. An organic thin film transistor array obtained by using the organic thin film transistor of any one of claims 1 to 6. A differential amplification circuit using the organic thin film transistor of any one of claims 1 to 6. An organic electronic device obtained by using a differential amplification circuit of claim 8 of the patent application.