WO2012115218A1 - Method for producing dianthra[2,3-b:2',3'-f]thieno[3,2-b]thiophene, and use thereof - Google Patents

Abstract

A dianthra[2,3-b:2',3'-f]thieno[3,2-b]thiophene is produced by subjecting a specific anthracene derivative to sulfur methylation, reacting the anthracene derivative with a specific tin compound, and then subjecting the reacted anthracene and tin compound to cyclization.

Description

Process for producing diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene and use thereof

The present invention relates to a novel process for producing diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene. The present invention also relates to an organic electronic device using the compound.

In recent years, interest in organic electronics devices has increased. Its features include that it has a flexible structure and can have a large area, and further enables an inexpensive and high-speed printing method in the device manufacturing process. Typical devices include organic photoelectric conversion elements, organic EL elements, organic transistor elements, and the like. As an organic photoelectric conversion element, research and development as an organic thin film solar cell, an optical sensor, and an image sensor have been made. Also, organic EL elements are applied from mobile phone displays to TVs, and organic transistor elements are being researched and developed into flexible displays and inexpensive ICs.

In developing these organic electronic devices, it is very important to develop materials that constitute the devices. For this reason, many materials have been studied in each field, but they cannot be said to have sufficient performance, and even now, materials that are useful for various devices are being actively developed. By using an organic material, it is possible to manufacture in a low temperature process that does not require high temperature processing, and the range of substrate materials that can be used is expanded. As a result, it has become possible to fabricate devices that are flexible, lightweight, and difficult to break. Further, in each device manufacturing process, there may be a case where a technique such as application of a solution in which a semiconductor material is dissolved, printing by ink jet, or the like may be employed, and thus a large area device may be manufactured at low cost. Various compounds for organic semiconductor materials can be selected, and an unprecedented function utilizing the characteristics is expected.

Various studies have been made on examples in which an organic compound is used as a semiconductor material. For example, a material using pentacene, thiophene, or an oligomer or polymer thereof is already known as a material having a hole transport property (patents). Reference 1 and Patent Document 2). Pentacene is an acene-based aromatic hydrocarbon in which five benzene rings are linearly condensed. A field effect transistor using this as a semiconductor material has a charge mobility comparable to amorphous silicon currently in practical use. It has been reported to show (carrier mobility). However, a field effect transistor using pentacene is deteriorated due to the environment and has a problem in stability. In addition, when using thiophene compounds, there are similar problems, and it is difficult to say that all of them are highly practical materials. In recent years, dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DNTT), which exhibits stable and high carrier mobility in the atmosphere, has been developed and attracts attention. (See Patent Document 3 and Non-Patent Document 1).

However, even these compounds require higher carrier mobility in order to be used for display applications such as organic EL, and in order to be used in applications such as solar cells and optical sensors, they have absorption for specific wavelengths. Some characteristic photoelectric conversion ability is necessary, and there is a strong demand from the market. Furthermore, from the viewpoint of durability, development of high-quality and high-performance organic semiconductor materials is required. For a compound in which the π system of dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DNTT) is expanded, Patent Document 3 discloses dianthra [2,3-b: 2 Although ', 3'-f] thieno [3,2-b] thiophene (DATT) has been described, it is difficult to say that its production method is an industrial production method, and makes this compound industrially usable. Therefore, it was necessary to establish a method for producing the compound that can be used industrially.

JP 2001-94107 A JP-A-6-177380 WO2008 / 050726 JP 2008-10541 A KR2001000098 publication WO2010 / 098372 JP 2009-196975 A WO2009 / 009790 publication JP 2010-258214 A

The present invention relates to a novel method for producing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene having a characteristic as a practical semiconductor exhibiting excellent carrier mobility. And an organic electronic device having a semiconductor layer formed of the compound.

As a result of intensive studies to solve the above problems, the present inventors synthesize dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene simply and efficiently. We have succeeded in developing a new manufacturing method that makes this possible. Moreover, it discovered that this compound has the characteristic as a practical semiconductor which shows the outstanding carrier mobility. Accordingly, it is possible to provide a semiconductor material composed of the compound and an organic electronic device having a semiconductor layer formed of the compound, and the present invention has been completed.

That is, the present invention
[1] A method for producing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene,
A step of reacting a compound represented by the formula (1) with dimethyl sulfide to obtain a compound represented by the formula (2);
A step of reacting a compound represented by formula (2) with a tin compound represented by formula (3) to obtain a compound represented by formula (4); and a compound represented by formula (4) Cyclization to obtain diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene;
Including the above method.

(In the formula, R ¹ and R ² represent a substituent, and Me represents a methyl group.)
[2] An organic semiconductor material containing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained by the method according to [1].
[3] An ink for producing a semiconductor device containing dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained by the method according to [1].
[4] An organic semiconductor thin film containing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained by the method according to [1].
[5] An organic electronic device having the organic semiconductor thin film layer according to [4].
[6] The organic electronics device according to [5], which is a photoelectric conversion element, an organic EL element, an organic semiconductor laser element, a liquid crystal display element, or a thin film transistor element.
[7] The organic electronic device according to [5], which is a solar cell.
[8] The organic electronic device according to [5], which is an optical sensor.
[9] A step of forming a semiconductor layer made of dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained by the method according to [1] on a substrate. [5] The manufacturing method of the organic electronics device as described in [5].
[10] The method for producing an organic electronic device according to [9], wherein the semiconductor layer is formed by a vapor deposition method.
[11] The method for producing an organic electronic device according to [9], wherein the semiconductor layer is formed by applying the semiconductor device manufacturing ink according to [3].
About.

According to the production method of the present invention, an intermediate of dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene can be produced with high selectivity, and dianthra [2,3-b : 2 ′, 3′-f] thieno [3,2-b] thiophene is an industrially useful production method capable of obtaining a good yield. In addition, when dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene produced by the production method is used in an organic electronic device, it is compared with a conventional organic semiconductor material. An organic electronic device exhibiting excellent performance can be provided.

FIG. 1 is a schematic view showing an embodiment of the field effect transistor of the present invention. FIG. 2 is a schematic view of a process for manufacturing one embodiment (bottom contact thin film transistor) of the field effect transistor of the present invention. FIG. 3 is a schematic view showing one embodiment of the organic EL element. FIG. 4 is a JV characteristic diagram of the organic solar battery element of Example 3.

The present invention will be described in detail. The present invention relates to a method for producing diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene. The present invention also relates to an organic electronic device obtained by forming a semiconductor layer using dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene as a semiconductor material.

Hereinafter, a method for producing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene will be described in detail. According to the production method of the present invention, the compound can be produced very efficiently. The reaction formula of the present invention is as follows. Hereinafter, reaction formulas (1), (2), and (3) will be described in order.

First, the compound (1) which is the starting material of the reaction formula (1) in the production of diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene will be described.

In the starting compound (1), R ¹ is preferably a methyl group, a trifluoromethyl group, a perfluorohexyl group, a 4-trifluoromethylphenyl group, or an aryl group in which all hydrogen atoms are replaced by fluorine atoms. there pentafluorophenyl group, a trifluoromethyl SO ₂ group, perfluorohexyl SO ₂ group, 4-trifluoromethylphenyl SO ₂ group, pentafluorophenyl SO ₂ group is an aryl group in which all hydrogen atoms replaced with fluorine atoms Is mentioned. Preferable R ¹ includes a methyl group and a trifluoromethyl SO ₂ group. Many of these compounds (1) are also available as commercial products.

Next, reaction formula (1) will be described in detail. This reaction is a novel reaction, and it is converted to SMe by using dimethyldisulfide (Me ₂ S ₂ ) highly selectively at the 3-position of the compound (1) which is a starting material bonded to the oxygen atom at the 2-position. It is a feature. In order to develop this reaction, the inventors examined a base (alkyl metal reagent, alkyl earth metal reagent), a reaction solvent, a reaction temperature, and an operation procedure for metalation by hydrogen extraction at the 3-position, The inventors have found a production method in which SMe is converted to dimethyldisulfide with high selectivity at the 3-position of compound (1).

As the base used for the reaction, it is desirable to use an alkali metal reagent, such as a lithium reagent, a sodium reagent, or a potassium reagent; an alkyl earth metal reagent, such as a magnesium reagent or a calcium reagent. Specifically, methyl lithium, n-butyl lithium, t-butyl lithium, phenyl lithium, methyl magnesium chloride, butyl magnesium chloride, or the like can be used. Particularly preferred is the use of butyl lithium, which is a stable and strong base.

The amount of the base used is desirably 0.5 mol or more and 10 mol or less with respect to 1 mol of the compound (1). You may add a base in the range of the said usage-amount to the reaction solution which added the compound (1) to the base. Thus, by adding a base in two steps, the extraction of the hydrogen atom at the 3-position of compound (1) may be smooth.

Further, in the method for producing a compound according to the present embodiment, a basic compound (additive) may be added together with the alkyl metal reagent for the purpose of stabilizing the lithium reagent. Examples of basic compounds include N, N, N′-trimethylethylenediamine, dimethylamine, diisopropylamine, morpholine, and the like.

It is desirable to carry out the reaction under nitrogen substitution and in a dry nitrogen stream.

The reaction temperature when reacting the compound (1) with a base is preferably in the range of −100 ° C. to 30 ° C., more preferably −30 ° C. to 10 ° C.

In this reaction, any solvent can be used, but an ether solvent, an aliphatic solvent, or an aromatic solvent is desirable. In addition, it is desirable to use a solvent obtained by drying moisture.

Examples of ether solvents used in the reaction include tetrahydrofuran (THF), diethyl ether, dimethoxyethane, dioxane and the like. Examples of the aliphatic solvent include n-pentane, n-hexane, and n-heptane, and examples of the aromatic solvent include toluene and xylene.

The amount of dimethyl disulfide used in the reaction is desirably 0.5 mol or more and 10 mol or less with respect to 1 mol of the compound (1).

When purifying the compound (2) obtained above, the purification method is not particularly limited, and a known purification method can be used according to the physical properties of the compound. Specifically, it can be purified by recrystallization, column chromatography or the like.

Subsequently, the compound (3) to be reacted with the compound (2) in the reaction formula (2) will be described.

In the formula (3) is a tin compound, R ² represents an alkyl group. Examples of the alkyl group include straight-chain or branched-chain alkyl groups, and the carbon number thereof is 1 to 8, preferably 1 to 4, and more preferably 4. Here, specific examples of the linear alkyl group include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl and the like. Specific examples of the branched chain alkyl group include C ₃ -C ₆ saturated branched chain alkyl groups such as i-propyl, i-butyl, t-butyl, i-pentyl, i-hexyl and the like. Preferably, it is an n-butyl group that is easily available.

Specific examples of the tin compound represented by the formula (3) are shown below, but the present invention is not limited thereto.

The compound (compound (4)) produced by the reaction formula (2) is trans-1,2-bis (3-methylthioanthracen-2-yl) ethene.

In the conventional reactions described in Patent Document 3 and Non-Patent Document 1, although it has been very difficult to synthesize the aldehyde form as a raw material for synthesizing the compound (4), the reaction of the reaction formula (2) of the present invention is It is a novel reaction, and it reacts with the compound (3) together with elimination of the oxygen atom at the 2-position of the two-molecule compound (2) having a MeS group at the 3-position to produce the compound (4) with high selectivity. It is a feature. In general, in the reaction represented by the reaction formula (2), a Pd-based compound is used as a catalyst. However, Pd is easily violated by a sulfur compound and may lose its activity immediately. For this reason, the present inventors have studied the catalyst, reaction solvent, reaction temperature, and operating procedure for effectively desorbing oxygen from the compound (2) and reacting with the compound (3) as described above. The present inventors have found a production method capable of obtaining compound (4) from 2) with high selectivity and high yield.

Here, R ¹ of the compound (2) can be converted into a more optimal substituent and used as necessary when the reaction of the reaction formula (2) is performed.

The mixing ratio of the compound (2) and the compound (3) when carrying out the reaction of the reaction formula (2) is that 1.8 mol to 2.5 mol of the compound (2) with respect to 1 mol of the compound (3). desirable. More preferably, it is carried out at 1.95 mol to 2.10 mol, and even more preferably at 1.95 mol to 2.05 mol.

As the catalyst used in the reaction, any Pd or Ni-based catalyst can be used, but at least one catalyst is tri-tert-butylphosphine, triadamantylphosphine, 1,3-bis ( 2,4,6-trimethylphenyl) imidazolidinium chloride, 1,3-bis (2,6-diisopropylphenyl) imidazolidinium chloride, 1,3-diadamantylimidazolidinium chloride, or a mixture thereof; metal Pd , Pd / C (with or without water), bis (triphenylphosphino) palladium dichloride (Pd (PPh ₃ ) ₂ Cl ₂ ), palladium (II) acetate (Pd (OAc) ₂ ), tetrakis (triphenylphosphine) palladium (Pd (PPh ₃ ) ₄ ), tetrakis (tripheny Ruphosphine) Nickel (Ni (PPh ₃ ) ₄ ), Nickel (II) acetylacetonate Ni (acac) ₂ , Dichloro (2,2′-bipyridine) nickel, Dibromobis (triphenylphosphine) nickel (Ni (PPh ₃ ) ₂ Br ₂ ), bis (diphenylphosphino) propanenickel dichloride (Ni ((dppp) Cl ₂ ), bis (diphenylphosphino) ethanenickel dichloride Ni (dppe) Cl ₂ , or mixtures thereof It may contain at least one compound selected from the group of nickel and palladium catalysts having a ligand, and preferred catalysts include Pd / C (hydrous or non-hydrous), Pd (PPh ₃ ) ₂ Cl ₂ , Pd (PPh _{3) 4,} and more preferably include, Pd (PP _{3) 2 Cl 2, Pd (} PPh 3) 4 and the like.

The amount of catalyst used is desirably 0.001 mol to 0.5 mol with respect to 1 mol of compound (2). You may add a catalyst in the range of the said usage-amount to the reaction solution which added the compound (2), the compound (3), and the catalyst. By adding the catalyst in two or more stages in this way, a reduction in the reaction rate due to catalyst deactivation may be suppressed.

The reaction temperature for reacting compound (2) with compound (3) is usually from −10 ° C. to 200 ° C. More preferably, it is 40 ° C to 180 ° C, and still more preferably 80 ° C to 150 ° C.

It is desirable to carry out the reaction under an inert atmosphere such as nitrogen substitution or argon substitution, or under a dry nitrogen stream.

In the reaction, a solvent may or may not be used. Any solvent can be used as long as it is a solvent used in ordinary organic synthesis. For example, aromatic compounds such as chlorobenzene, o-dichlorobenzene, bromobenzene, nitrobenzene, toluene, xylene, and saturated aliphatic hydrocarbons such as n-hexane, n-heptane, n-pentane; cyclohexane, cycloheptane, cyclopentane Alicyclic hydrocarbons such as n-propyl bromide, n-butyl chloride, n-butyl bromide, dichloromethane, dibromomethane, dichloropropane, dibromopropane, dichloroethane, dibromoethane, dichloropropane, dibromopropane, dichlorobutane, chloroform, Saturated aliphatic halogenated hydrocarbons such as bromoform, carbon tetrachloride, carbon tetrabromide, trichloroethane, tetrachloroethane, pentachloroethane; chlorocyclohexane, chlorocyclopentane, bromocyclope Halogenated cyclic hydrocarbons such as tan; esters such as ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate; acetone And ketones such as methyl ethyl ketone and methyl isobutyl ketone. These solvents may be used alone or in combination of two or more.

Also, it is preferable to use at least one high boiling point solvent having a boiling point of 100 ° C. or higher as the reaction solvent because the reaction rate is greatly improved and the selectivity of the reaction is further increased.

High boiling point solvents having a boiling point of 100 ° C. or higher are amides (N-methyl-2-pyrrolidone (hereinafter referred to as NMP), N, N-dimethylformamide (hereinafter abbreviated as DMF), N, N-dimethylacetamide (hereinafter referred to as DMAc). )); Glycols (ethylene glycol, propylene glycol, polyethylene glycol); and sulfoxides (dimethyl sulfoxide (hereinafter abbreviated as DMSO)) are preferred, and N-methyl-2-pyrrolidone, N, N-dimethyl are more preferred. Formamide, N, N-dimethylacetamide.

When purifying the obtained compound (4), the purification method is not particularly limited, and a known purification method can be used according to the physical properties of the compound (4). Specifically, it can be purified by recrystallization, column chromatography or the like.

Thereafter, the following dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene is derived from the compound (4) by the reaction of the reaction formula (3).

The thin film of the present invention refers to a thin film formed from the dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene of the present invention or a composition containing the same. The thickness of the thin film varies depending on the application, but is usually from 0.1 nm to 100 μm, preferably from 0.5 nm to 30 μm, more preferably from 1 nm to 20 μm.

The thin film forming method of the present invention generally includes resistance heating evaporation, which is a vacuum process, electron beam evaporation, sputtering, molecular lamination, etc., and spin coating, drop casting, dip coating, and spraying, which are solution processes. Letterpress printing methods such as printing, flexographic printing, resin letterpress printing, offset printing methods, dry offset printing methods, pad printing methods, lithographic printing methods such as lithographic printing methods, intaglio printing methods such as gravure printing methods, silk screen printing methods, Examples thereof include a stencil printing method such as a stencil printing method and a lithographic printing method, an ink jet printing method, a microcontact printing method, and a method in which a plurality of these methods are combined. Usually, a resistance heating vapor deposition method that is a vacuum process, a spin coating method that is a solution process, a dip coating method, an ink jet method, screen printing, letterpress printing, and the like are preferable. Moreover, since the film forming method required in each organic electronic device is different, it will be described later in the section of each device.

The organic electronic device of the present invention contains the above-mentioned dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene as an electronic material for electronics use. Examples of the organic electronic device include a thin film transistor, an organic EL element, a liquid crystal display element, a photoelectric conversion element, and an organic semiconductor laser element. These will be described in detail.

First, the thin film transistor will be described in detail.
A thin film transistor has two electrodes (a source electrode and a drain electrode) in contact with a semiconductor, and a current flowing between the electrodes is controlled by a voltage applied to another electrode called a gate electrode.

Generally, a thin film transistor element often has a structure in which a gate electrode is insulated by an insulating film (Metal-Insulator-Semiconductor: MIS structure). An insulating film using a metal oxide film is called a MOS structure. In addition, there is a structure in which a gate electrode is formed through a Schottky barrier, that is, an MES structure, but in the case of a thin film transistor using an organic semiconductor material, an MIS structure is often used.

Hereinafter, the organic thin film transistor according to the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to these structures.
FIG. 1 shows some embodiments of the thin film transistor (element) of the present invention. In each example, 1 is a source electrode, 2 is a semiconductor layer, 3 is a drain electrode, 4 is an insulator layer, 5 is a gate electrode, and 6 is a substrate. In addition, arrangement | positioning of each layer and an electrode can be suitably selected according to the use of an element. A to D are called lateral transistors because a current flows in a direction parallel to the substrate. A is called a bottom contact structure, and B is called a top contact structure. C has a source and drain electrode and an insulator layer on a semiconductor and further has a gate electrode formed thereon, which is called a bottom gate structure. D has a structure called a top & bottom contact type transistor. E is a schematic diagram of a transistor having a vertical structure, that is, a static induction transistor (SIT). In this SIT, a large amount of carriers can move at a time because the current flow spreads in a plane. Further, since the source electrode and the drain electrode are arranged vertically, the distance between the electrodes can be reduced, so that the response is fast. Therefore, it can be preferably applied to uses such as high-speed switching with a large current. Note that although a substrate is not described in E in FIG. 1, a substrate is usually provided outside the source and drain electrodes represented by 1 and 3 in E in FIG. 1.

Each component in each embodiment will be described.
The substrate 6 needs to be able to hold each layer formed thereon without peeling off. For example, insulating materials such as resin plates, films, paper, glass, quartz, ceramics, etc .; those in which an insulating layer is formed on a conductive substrate such as metal or alloy by coating; materials consisting of various combinations such as resin and inorganic materials Can be used. Examples of the resin film that can be used include polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyamide, polyimide, polycarbonate, cellulose triacetate, and polyetherimide. When a resin film or paper is used, the element can have flexibility, is flexible and lightweight, and improves practicality. The thickness of the substrate is usually 1 μm to 10 mm, preferably 5 μm to 5 mm.

A conductive material is used for the source electrode 1, the drain electrode 3, and the gate electrode 5. For example, platinum, gold, silver, aluminum, chromium, tungsten, tantalum, nickel, cobalt, copper, iron, lead, tin, titanium, indium, palladium, molybdenum, magnesium, calcium, barium, lithium, potassium, sodium, and other metals And alloys containing them; conductive oxides such as InO ₂ , ZnO ₂ , SnO ₂ , ITO; conductive polymer compounds such as polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylene, vinylene, polydiacetylene; silicon, germanium And semiconductors such as gallium arsenide; carbon materials such as carbon black, fullerene, carbon nanotubes, and graphite; In addition, the conductive polymer compound or the semiconductor may be doped. Examples of the dopant include inorganic acids such as hydrochloric acid and sulfuric acid; organic acids having an acidic functional group such as sulfonic acid; Lewis acids such as PF ₅ , AsF ₅ and FeCl ₃ ; halogen atoms such as iodine; lithium, Metal atoms such as sodium and potassium; and the like. Boron, phosphorus, arsenic and the like are also frequently used as dopants for inorganic semiconductors such as silicon.
In addition, a conductive composite material in which carbon black, metal particles, or the like is dispersed in the above dopant is also used.

Further, the distance (channel length) between the source and drain electrodes is an important factor that determines the characteristics of the device. The channel length is usually 0.1 to 300 μm, preferably 0.5 to 100 μm. If the channel length is short, the amount of current that can be extracted increases. However, since a leak current or the like occurs, an appropriate channel length is required. The width (channel width) between the source and drain electrodes is usually 10 to 10,000 μm, preferably 100 to 5000 μm. Further, this channel width can be made longer by forming the electrode structure into a comb structure, etc., and may be set to an appropriate length depending on the required amount of current or the structure of the element. .
Each structure (shape) of the source and drain electrodes will be described. The structure of the source and drain electrodes may be the same or different. The length of the electrode may be the same as the channel width. There is no particular limitation on the width of the electrode, but a shorter one is preferable in order to reduce the area of the element as long as the electrical characteristics can be stabilized. The width of the electrode is usually 0.1 to 1000 μm, preferably 0.5 to 100 μm. The thickness of the electrode is usually 0.1 to 1000 nm, preferably 1 to 500 nm, more preferably 5 to 200 nm. A wiring is connected to each of the electrodes 1, 3, and 5, but the wiring is also made of substantially the same material as the electrode.

An insulating material is used for the insulator layer 4. For example, polymers such as polyparaxylylene, polyacrylate, polymethyl methacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, phenol resin, fluorine resin And copolymers combining these; metal oxides such as silicon dioxide, aluminum oxide, titanium oxide, and tantalum oxide; ferroelectric metal oxides such as SrTiO ₃ and BaTiO ₃ ; nitrides such as silicon nitride and aluminum nitride; A sulfide; a dielectric such as fluoride; or a polymer in which particles of the dielectric are dispersed can be used. The film thickness of the insulator layer 4 varies depending on the material, but is usually 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, more preferably 1 nm to 10 μm.

As the material for the semiconductor layer 2, the dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene of the present invention or a composition containing the same is used. The semiconductor layer 2 is formed as a thin film using the above method. In this case, it is preferable to use a single dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene as an organic semiconductor material, but the characteristics of the thin film transistor can be improved In order to impart the above characteristics, other organic semiconductor materials and various additives may be mixed as necessary. These include cases in which other organic semiconductor materials and dopants are co-deposited in a vapor deposition process, or when a solvent, a dispersant, a surfactant, a leveling agent, a surface tension adjusting agent, etc. used in a solution process are mixed to form a composition. An example is given. The semiconductor layer 2 may be composed of a plurality of layers.

The above additives are usually added in the range of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight, when the total amount of the organic semiconductor material is 1. It is good to do. This is not the case when the semiconductor composition is used as the organic semiconductor material.
A plurality of layers may also be formed for the semiconductor layer, but a single layer structure is more preferable. The thickness of the semiconductor layer 2 is preferably as thin as possible without losing necessary functions. In the lateral thin film transistor as shown in FIGS. 1A, 1B, and 1D, the leakage current increases as the film thickness increases. Therefore, if the film thickness exceeds a predetermined value, the element characteristics do not depend on the film thickness. The film thickness of the semiconductor layer for exhibiting the necessary function is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.

In the thin film transistor of the present invention, for example, other layers can be provided as necessary between the substrate layer and the insulating film layer, between the insulating film layer and the semiconductor layer, or on the outer surface of the element. For example, when a protective layer is formed directly on the organic semiconductor layer or via another layer, the influence of outside air such as humidity can be reduced, and the ON / OFF ratio of the element can be increased. There is also an advantage that the electrical characteristics can be stabilized.

The material of the protective layer is not particularly limited. For example, films made of various resins such as acrylic resin such as epoxy resin and polymethyl methacrylate, polyurethane, polyimide, polyvinyl alcohol, fluororesin, polyolefin, etc .; silicon oxide, aluminum oxide, nitriding A film made of an inorganic oxide film such as silicon and a dielectric film such as a nitride film is preferably used, and a resin (polymer) having a low oxygen or moisture permeability and a low water absorption rate is particularly preferable. In recent years, protective materials developed for organic EL displays can also be used. The film thickness of the protective layer can be selected according to the purpose, but is usually 100 nm to 1 mm.

In addition, it is possible to improve characteristics as a thin film transistor element by performing surface treatment in advance on a substrate or an insulator layer on which an organic semiconductor layer is stacked. For example, by adjusting the degree of hydrophilicity / hydrophobicity of the substrate surface, the film quality of the film formed thereon can be improved. In particular, the characteristics of organic semiconductor materials can vary greatly depending on the state of the film, such as molecular orientation. For this reason, the surface treatment on the substrate or the like can control the molecular orientation at the interface between the substrate and the organic semiconductor layer to be formed thereafter, and can reduce the trap sites on the substrate and the insulator layer. Therefore, it is considered that characteristics such as carrier mobility are improved.
The trap site refers to a functional group such as a hydroxyl group present in an untreated substrate. When such a functional group is present, electrons are attracted to the functional group, and as a result, carrier mobility is lowered. Therefore, reducing trap sites is often effective for improving characteristics such as carrier mobility.

Examples of the substrate treatment for improving the characteristics as described above include hydrophobization treatment with hexamethyldisilazane, cyclohexene, octyltrichlorosilane, octadecyltrichlorosilane, etc .; acid treatment with hydrochloric acid, sulfuric acid, acetic acid, etc .; sodium hydroxide, Alkaline treatment with potassium hydroxide, calcium hydroxide, ammonia, etc .; ozone treatment; fluorination treatment; plasma treatment with oxygen or argon; Langmuir / Blodgett film formation treatment; other insulator or semiconductor thin film formation treatment; Examples include mechanical treatment; electrical treatment such as corona discharge; and rubbing treatment using fibers and the like.

In these embodiments, for example, a vacuum deposition method, a sputtering method, a coating method, a printing method, a sol-gel method, or the like can be appropriately employed as a method of providing each layer such as a substrate layer and an insulating film layer or an insulating film layer and an organic semiconductor layer. .

Next, a method for manufacturing a thin film transistor element according to the present invention will be described below with reference to FIG. 2 by taking the bottom contact type thin film transistor shown in the embodiment example A of FIG. 1 as an example. This manufacturing method can be similarly applied to the thin film transistors of other embodiments described above.

(Thin film transistor substrate and substrate processing)
The thin film transistor of the present invention is manufactured by providing various layers and electrodes necessary on the substrate 6 (see FIG. 2A). As the substrate, those described above can be used. It is also possible to perform the above-described surface treatment or the like on this substrate. The thickness of the substrate 6 is preferably thin as long as necessary functions are not hindered. Although it varies depending on the material, it is usually 1 μm to 10 mm, preferably 5 μm to 5 mm. Moreover, you may make it give the function of an electrode to a board | substrate as needed.

(About formation of gate electrode)
A gate electrode 5 is formed on the substrate 6 (see FIG. 2B). The electrode material described above is used as the electrode material. As a method for forming the electrode film, various methods can be used. For example, a vacuum deposition method, a sputtering method, a coating method, a thermal transfer method, a printing method, a sol-gel method, and the like are employed. It is preferable to perform patterning as necessary so as to obtain a desired shape during or after film formation. Various methods can be used as the patterning method, and examples thereof include a photolithography method in which patterning and etching of a photoresist are combined. Moreover, it is also possible to perform patterning using a printing method such as ink jet printing, screen printing, offset printing, letterpress printing or the like, a soft lithography method such as a micro contact printing method, and a method combining a plurality of these methods. The film thickness of the gate electrode 5 varies depending on the material, but is usually 0.1 nm to 10 μm, preferably 0.5 nm to 5 μm, more preferably 1 nm to 3 μm. Moreover, when it serves as a gate electrode and a board | substrate, it may be larger than said film thickness.

(About formation of insulator layer)
An insulator layer 4 is formed over the gate electrode 5 (see FIG. 2 (3)). As the insulator material, those described above are used. Various methods can be used to form the insulator layer 4. For example, spin coating, spray coating, dip coating, casting, bar coating, blade coating and other coating methods, screen printing, offset printing, inkjet printing methods, vacuum deposition, molecular beam epitaxial growth, ion cluster beam method, ion plating Examples thereof include dry process methods such as a coating method, a sputtering method, an atmospheric pressure plasma method, and a CVD method. In addition, a sol-gel method, alumite on aluminum, a method of forming an oxide film on a metal such as silicon dioxide on silicon, and the like are employed. It should be noted that at the portion where the insulator layer and the semiconductor layer are in contact, molecules constituting the semiconductor at the interface between the two layers, for example, dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2] of the present invention. -B] In order to satisfactorily align the thiophene molecules, the insulator layer may be subjected to a predetermined surface treatment. As the surface treatment method, the same surface treatment as that of the substrate can be used. The thickness of the insulator layer 4 is preferably as thin as possible without impairing its function. Usually, the thickness is 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, more preferably 5 nm to 10 μm.

(Formation of source electrode and drain electrode)
The source electrode 1 and the drain electrode 3 can be formed in accordance with the case of the gate electrode 5 (see FIG. 2 (4)). Various additives can be used to reduce the contact resistance with the organic semiconductor layer.

(Formation of organic semiconductor layer)
As described above, the diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene or a composition thereof is used as the organic semiconductor material. In forming the organic semiconductor layer, various methods can be used. Formation method in a vacuum process such as sputtering method, CVD method, molecular beam epitaxial growth method, vacuum deposition method; coating method such as dip coating method, die coater method, roll coater method, bar coater method, spin coating method, ink jet method, It is roughly classified into solution forming methods such as screen printing, offset printing, and microcontact printing.

In the case of forming an organic thin film to be a semiconductor layer using the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention as a semiconductor material, A method of forming an organic thin film formed by a vacuum process as a semiconductor layer is preferable, and a vacuum evaporation method is more preferable. It is possible to form a film by a solution process, and it is possible to adopt a printing method at a low cost.

A method for obtaining an organic semiconductor layer by depositing an organic semiconductor material by a vacuum process will be described. A method in which the organic semiconductor material is heated in a crucible or a metal boat under vacuum, and the evaporated organic semiconductor material is attached (evaporated) to a substrate (exposed portions of the insulator layer, the source electrode and the drain electrode), that is, vacuum. A vapor deposition method is preferably employed. At this time, the degree of vacuum is usually 1.0 × 10 ⁻¹ Pa or less, preferably 1.0 × 10 ⁻³ Pa or less. In addition, since the characteristics of the organic semiconductor film and thus the thin film transistor may change depending on the substrate temperature during vapor deposition, it is preferable to select the substrate temperature carefully. The substrate temperature during vapor deposition is usually 0 to 200 ° C., preferably 10 to 150 ° C., more preferably 15 to 120 ° C., and further preferably 25 to 100 ° C.
The deposition rate is usually 0.001 to 10 nm / second, preferably 0.01 to 1 nm / second. The film thickness of the organic semiconductor layer formed from the organic semiconductor material is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.
Instead of the vapor deposition method in which the organic semiconductor material for forming the organic semiconductor layer is heated and evaporated to adhere to the substrate, accelerated ions such as argon collide with the material target to knock out the material atoms and adhere to the substrate. A sputtering method may be used.

Next, a method for obtaining an organic semiconductor layer by forming a film by a solution process will be described. The dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention is dissolved or dispersed in a solvent or the like, and if necessary, other low molecular compounds or polymers. A composition containing additives such as a compound, a dopant, a dispersant, a surfactant, a leveling agent, and a surface tension adjusting agent is prepared as an ink for producing a semiconductor device, and the substrate (insulator layer, source electrode and drain electrode exposed) Part). Coating methods include casting, spin coating, dip coating, blade coating, wire bar coating, spray coating, and other coating methods, inkjet printing, screen printing, offset printing, letterpress printing, and other micro contact printing methods. The method of soft lithography, etc., or a method combining a plurality of these methods may be employed.
Furthermore, as a method similar to the coating method, a Langmuir project method in which a monomolecular film of an organic semiconductor layer produced by dropping the above ink on a water surface is transferred to a substrate and laminated, and two materials of liquid crystal or a melt state are used. It is also possible to adopt a method of sandwiching between substrates or introducing between substrates by capillary action. The environment such as the temperature of the substrate and the composition at the time of film formation is also important, and the characteristics of the transistor may change depending on the temperature of the substrate and the composition. The substrate temperature at the time of vapor deposition is usually 0 to 200 ° C., preferably 10 to 120 ° C., more preferably 15 to 100 ° C. Special care must be taken because it depends greatly on the solvent in the composition to be used.

The film thickness of the organic semiconductor layer produced by this method is preferably thinner as long as the function is not impaired. There is a concern that the leakage current increases as the film thickness increases. The film thickness of the organic semiconductor layer is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.

The characteristics of the organic semiconductor layer thus formed (see FIG. 2 (5)) can be further improved by post-processing. For example, it is considered that heat treatment reduces strain in the film generated during film formation, reduces pinholes, etc., and can control the arrangement and orientation in the film. The semiconductor characteristics can be improved and stabilized. When the thin film transistor of the present invention is produced, this heat treatment is effective for improving the characteristics. This heat treatment is performed by heating the substrate after forming the organic semiconductor layer. The temperature of the heat treatment is not particularly limited, but is usually room temperature to 150 ° C., preferably 40 to 120 ° C., more preferably 45 to 100 ° C. The heat treatment time at this time is not particularly limited, but is usually about 1 minute to 24 hours, preferably about 2 minutes to 3 hours. The atmosphere at that time may be air, but may be an inert atmosphere such as nitrogen or argon.
In addition, as a post-treatment method for other organic semiconductor layers, a property change due to oxidation or reduction is induced by treatment with an oxidizing or reducing gas such as oxygen or hydrogen or an oxidizing or reducing liquid. You can also. This is often used for the purpose of increasing or decreasing the carrier density in the film, for example.

In addition, in a technique called doping, characteristics of the organic semiconductor layer can be changed by adding a trace amount of elements, atomic groups, molecules, and polymers to the organic semiconductor layer. For example, oxygen, hydrogen, hydrochloric acid, sulfuric acid, sulfonic acid and other acids; PF ₅ , AsF ₅ , FeCl _{3 and} other Lewis acids; iodine and other halogen atoms; sodium and potassium and other metal atoms; various organic semiconductor materials and the like can do. This can be achieved by bringing these gases into contact with the organic semiconductor layer, immersing them in a solution, or performing an electrochemical doping treatment. These dopings may be added during the synthesis of the organic semiconductor compound, even after the organic semiconductor layer is not prepared, or may be added to the ink in the process of preparing the organic semiconductor layer using the ink for preparing the organic semiconductor element. It can be added in the process step of forming a thin film. In addition, a doping material is added to the material that forms the organic semiconductor layer during vapor deposition and co-evaporation is performed, or the organic semiconductor layer is mixed with the surrounding atmosphere when the organic semiconductor layer is formed (in the environment where the doping material is present, the organic semiconductor It is also possible to perform doping by accelerating ions in a vacuum and colliding with the film.

These doping effects include changes in electrical conductivity due to increase or decrease in carrier density, changes in carrier polarity (P-type and N-type), changes in Fermi level, and the like. Such doping is often used particularly in semiconductor elements using inorganic materials such as silicon.

(Protective layer)
When the protective layer 7 is formed on the organic semiconductor layer, there is an advantage that the influence of outside air can be minimized and the electrical characteristics of the organic thin film transistor can be stabilized (see FIG. 2 (6)). The materials described above are used as the material for the protective layer. The protective layer 7 may have any thickness depending on the purpose, but is usually 100 nm to 1 mm.
Various methods can be employed to form the protective layer. When the protective layer is made of a resin, for example, a method of applying a resin solution and then drying to form a resin film; applying or vapor-depositing a resin monomer And then a method of polymerizing. Cross-linking treatment may be performed after film formation.
When the protective layer is made of an inorganic material, for example, a formation method in a vacuum process such as a sputtering method or a vapor deposition method, or a formation method in a solution process such as a sol-gel method can be used.
In the thin film transistor of the present invention, a protective layer can be provided between the layers in addition to the organic semiconductor layer as necessary. These layers may help stabilize the electrical characteristics of the thin film transistor.

According to the present invention, since dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene is used as an organic semiconductor material, it can be manufactured in a relatively low temperature process. is there. Therefore, flexible materials such as plastic plates and plastic films that could not be used under conditions exposed to high temperatures can also be used as the substrate. As a result, it is possible to manufacture a light, flexible, and hard-to-break element, which can be used as a switching element for an active matrix of a display.

The thin film transistor of the present invention can also be used as a digital element and an analog element such as a memory circuit element, a signal driver circuit element, and a signal processing circuit element. Further, by combining these, it is possible to produce an IC card or an IC tag. Furthermore, since the thin film transistor of the present invention can change its characteristics by an external stimulus such as a chemical substance, it can be used as an FET sensor.

Next, the organic EL device of the present invention will be described in detail.
Organic EL elements are attracting attention and can be used for applications such as solid, self-luminous large-area color display and illumination, and many developments have been made. The structure has a structure having two layers of a light emitting layer and a charge transport layer between a counter electrode composed of a cathode and an anode; an electron transport layer, a light emitting layer and a hole transport layer stacked between the counter electrodes. Known are those having a structure having three layers; and those having three or more layers; and those having a single light-emitting layer.
Here, the hole transport layer has a function of injecting holes from the anode, transporting holes to the light emitting layer, facilitating injection of holes into the light emitting layer, and a function of blocking electrons. The electron transport layer has a function of injecting electrons from the cathode, transporting electrons to the light emitting layer, facilitating injection of electrons into the light emitting layer, and blocking holes. Further, in the light emitting layer, excitons are generated by recombination of the injected electrons and holes, and the energy emitted in the process of radiative deactivation of the excitons is detected as light emission. Preferred embodiments of the organic EL device of the present invention are described below.

The organic EL device of the present invention is a device that emits light by electrical energy, in which one or more organic thin films are formed between an anode and a cathode.
The anode that can be used in the organic EL device of the present invention is an electrode having a function of injecting holes into a hole injection layer, a hole transport layer, and a light emitting layer. In general, metal oxides, metals, alloys, conductive materials, and the like having a work function of 4.5 eV or more are suitable. Specifically, although not particularly limited, conductive metal oxides such as tin oxide (NESA), indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), gold, silver, platinum, chromium And metals such as aluminum, iron, cobalt, nickel and tungsten, inorganic conductive materials such as copper iodide and copper sulfide, conductive polymers such as polythiophene, polypyrrole and polyaniline, and carbon. Among these, it is preferable to use ITO or NESA.
If necessary, the anode may be made of a plurality of materials or may be composed of two or more layers. The resistance of the anode is not limited as long as it can supply a current sufficient for light emission of the element, but it is preferably low resistance from the viewpoint of power consumption of the element. For example, an ITO substrate having a sheet resistance value of 300Ω / □ or less functions as an element electrode, but since it is possible to supply a substrate of several Ω / □, it is desirable to use a low-resistance product. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually 5 to 500 nm, preferably 10 to 300 nm. Examples of film forming methods such as ITO include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method.

The cathode that can be used in the organic EL device of the present invention is an electrode having a function of injecting electrons into an electron injection layer, an electron transport layer, and a light emitting layer. In general, a metal or an alloy having a small work function (approximately 4 eV or less) is suitable. Specific examples include platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, calcium, and magnesium, but are not particularly limited. Lithium, sodium, potassium, calcium, and magnesium are preferable for increasing the electron injection efficiency and improving the device characteristics.
As the alloy, an alloy with a metal such as aluminum or silver containing these low work function metals or an electrode having a structure in which these are laminated can be used. An inorganic salt such as lithium fluoride can be used for the electrode having a laminated structure. Moreover, when light emission is taken out not to the anode side but to the cathode side, a transparent electrode that can be formed at a low temperature may be used. Examples of the film forming method include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method, but are not particularly limited. The resistance of the cathode is not limited as long as it can supply a current sufficient for light emission of the element, but it is preferably low resistance from the viewpoint of power consumption of the element, and preferably about several hundred to several Ω / □. The film thickness is usually 5 to 500 nm, preferably 10 to 300 nm.
Furthermore, for sealing and protection, oxides such as titanium oxide, silicon nitride, silicon oxide, silicon nitride oxide, germanium oxide, nitrides, or mixtures thereof, polyvinyl alcohol, vinyl chloride, hydrocarbon polymers, fluorine The cathode can be protected with a polymer, etc., and sealed with a dehydrating agent such as barium oxide, phosphorus pentoxide, or calcium oxide.

In order to extract light emission, it is generally preferable to form an electrode on a substrate that is sufficiently transparent in the light emission wavelength region of the element. Examples of the transparent substrate include a glass substrate and a polymer substrate. As the glass substrate, soda lime glass, non-alkali glass, quartz, or the like is used. The glass substrate may have a thickness sufficient to maintain mechanical and thermal strength, and a thickness of 0.5 mm or more is preferable. As for the material of the glass, it is better that there are few ions eluted from the glass, and alkali-free glass is preferred. As such, since soda lime glass provided with a barrier coat such as SiO ₂ is commercially available, it can also be used. Examples of the substrate made of a polymer other than glass include polycarbonate, polypropylene, polyethersulfone, polyethylene terephthalate, and an acrylic substrate.

The organic thin film included in the organic EL element of the present invention is formed of one or more layers between the anode and cathode electrodes. By incorporating the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention into the organic thin film, a device that emits light by electric energy can be obtained.

The “layer” of one or more layers forming the organic thin film in the present invention is a hole transport layer, an electron transport layer, a hole transport light-emitting layer, an electron transport light-emitting layer, a hole block layer, an electron block As shown in the layer, the hole injection layer, the electron injection layer, the light emitting layer, or the following structural example 9), it means a single layer having the functions of these layers. Examples of the configuration of the layer forming the organic thin film in the present invention include the following configuration examples 1) to 9), and any configuration may be used.

Configuration Example 1) Hole transport layer / electron transport light emitting layer.
2) Hole transport layer / light emitting layer / electron transport layer.
3) Hole transporting light emitting layer / electron transporting layer.
4) Hole transport layer / light emitting layer / hole blocking layer.
5) Hole transport layer / light emitting layer / hole blocking layer / electron transport layer.
6) Hole transporting light emitting layer / hole blocking layer / electron transporting layer.
7) In each of the combinations 1) to 6), a hole injection layer is further provided in front of the hole transport layer or the hole transport light emitting layer.
8) A structure in which an electron injecting layer is further provided in front of the electron transporting layer or the electron transporting light emitting layer in each of the combinations 1) to 7).
9) A configuration in which materials used in the combinations 1) to 8) are mixed, and only one layer containing the mixed materials is included.

Note that the above 9) may be a single layer formed of a material generally called a bipolar light-emitting material; or only one layer including a light-emitting material and a hole transport material or an electron transport material. In general, with a multilayer structure, charges, that is, holes and / or electrons can be efficiently transported and these charges can be recombined. In addition, by suppressing the quenching of charges, the stability of the element can be prevented from being lowered and the light emission efficiency can be improved.

The hole injection layer and the transport layer are formed by laminating a hole transport material alone or a mixture of two or more kinds of the materials. Examples of the hole transport material include N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1′-diamine, N, N′-dinaphthyl-N, Triphenylamines such as N′-diphenyl-4,4′-diphenyl-1,1′-diamine, bis (N-allylcarbazole) or bis (N-alkylcarbazole) s, pyrazoline derivatives, stilbene compounds, hydrazones In the case of a polymer compound, a triazole derivative, a heterocyclic compound typified by an oxadiazole derivative or a porphyrin derivative, or a polymer system, a polycarbonate, a styrene derivative, polyvinyl carbazole, polysilane, or the like having the monomer in the side chain can be preferably used. There is no particular limitation as long as a thin film necessary for device fabrication is formed, holes can be injected from the electrodes, and holes can be transported. The hole injection layer provided between the hole transport layer and the anode for improving the hole injection property includes phthalocyanine derivatives, starburst amines such as m-MTDATA, polythiophene such as PEDOT in the polymer system, polyvinyl Those prepared with carbazole derivatives and the like can be mentioned.

As an electron transport material, it is necessary to efficiently transport electrons from the negative electrode between electrodes to which an electric field is applied. The electron transport material has high electron injection efficiency, and it is preferable to transport the injected electrons efficiently. For that purpose, it is required that the substance has a high electron affinity, a high electron mobility, excellent stability, and a substance that does not easily generate trapping impurities during manufacturing and use. As substances satisfying such conditions, quinolinol derivative metal complexes represented by tris (8-quinolinolato) aluminum complexes, tropolone metal complexes, perylene derivatives, perinone derivatives, naphthalimide derivatives, naphthalic acid derivatives, oxazole derivatives, oxadiazoles Derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, benzoxazole derivatives, quinoxaline derivatives, and the like are exemplified, but are not particularly limited. These electron transport materials are used alone, but may be laminated or mixed with different electron transport materials. Examples of the electron injection layer provided between the electron transport layer and the cathode for improving the electron injection property include metals such as cesium, lithium, and strontium, lithium fluoride, and the like.

The hole blocking layer is formed by laminating and mixing hole blocking substances alone or two or more kinds. As the hole blocking substance, phenanthroline derivatives such as bathophenanthroline and bathocuproin, silole derivatives, quinolinol derivative metal complexes, oxadiazole derivatives and oxazole derivatives are preferable. The hole blocking substance is not particularly limited as long as it is a compound that can prevent holes from flowing out from the cathode side to the outside of the device and thereby reducing luminous efficiency.

The light emitting layer means an organic thin film that emits light, and can be said to be, for example, a hole transporting layer, an electron transporting layer, or a bipolar transporting layer having strong light emitting properties. The light emitting layer only needs to be formed of a light emitting material (host material, dopant material, etc.), which may be a mixture of a host material and a dopant material or a host material alone. Each of the host material and the dopant material may be one kind or a combination of a plurality of materials. The dopant material may be included in the host material as a whole, or may be included partially. The dopant material may be either laminated or dispersed. Examples of the light emitting layer include the above-described hole transport layer and electron transport layer. Materials used for the light-emitting layer include carbazole derivatives, anthracene derivatives, naphthalene derivatives, phenanthrene derivatives, phenylbutadiene derivatives, styryl derivatives, pyrene derivatives, perylene derivatives, quinoline derivatives, tetracene derivatives, perylene derivatives, quinacridone derivatives, coumarin derivative porphyrins. Derivatives and phosphorescent metal complexes (Ir complex, Pt complex, Eu complex, etc.) can be mentioned.

These thin film formation methods are generally vacuum heating processes such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, solution processes such as casting, spin coating, dip coating, blade coating, wire bar coating, spraying. A coating method such as coating, a printing method such as ink jet printing, screen printing, offset printing, and relief printing, a soft lithography method such as a microcontact printing method, and a combination of these methods may be employed. The thickness of each layer depends on the resistance value and charge mobility of each substance and cannot be limited, but is selected from 0.5 to 5000 nm. The thickness is preferably 1 to 1000 nm, more preferably 5 to 500 nm.

Among the organic thin films possessed by the organic EL device of the present invention, the diant [2 of the present invention is formed on one or a plurality of thin films such as a light emitting layer, a hole transport layer, and an electron transport layer, which are present between the anode and cathode electrodes. , 3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene, an element that efficiently emits light even with low electric energy can be obtained.

The organic EL device of the present invention comprises the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention in one or more layers between the anode and the cathode. It can be obtained by forming a layer. In particular, there is no limitation on the site where the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention is used. It can be suitably used as a host material combined with the material.

In the organic EL device of the present invention, the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention is preferably used as a hole transport layer or a light emitting layer. it can. For example, it can be used in combination with the above-described electron transport material, hole transport material, light emitting material, or the like. Preferably, quinolinol derivative metal complex represented by tris (8-quinolinolato) aluminum complex, tropolone metal complex, perylene derivative, perinone derivative, naphthalimide derivative, naphthalic acid derivative, bisstyryl derivative, pyrazine derivative, phenanthroline derivative, benzoxazole derivative Quinoxaline derivatives, triphenylamines, bis (N-allylcarbazole) or bis (N-alkylcarbazole) s, pyrazoline derivatives, stilbene compounds, hydrazone compounds, heterocyclic compounds represented by oxadiazole derivatives, etc. Although it is mentioned, it is not particularly limited. These can be used alone, but can also be used by laminating or mixing different materials.

As a specific example of the dopant material when the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention is used as a host material in combination with a dopant material, bis ( Perylene derivatives such as diisopropylphenyl) perylenetetracarboxylic imide, perinone derivatives, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM) and its analogs, magnesium phthalocyanine metal phthalocyanine derivatives such as aluminum chloro phthalocyanine, rhodamine compounds, Deazafurabin derivatives, coumarin derivatives, oxazine compounds, squarylium compounds, violanthrone compound, Nile red, pyrromethene derivatives such as 5-Shianopirometen -BF ₄ complex, further phosphorescent material Eu complexes having acetylacetone, benzoylacetone and phenanthroline as ligands, porphyrins such as Ir complexes, Ru complexes, Pt complexes, Os complexes, ortho metal metal complexes, etc. can be used, but are not limited to these. It is not something. In addition, when two kinds of dopant materials are mixed, it is also possible to obtain light emission with improved color purity by efficiently transferring energy from the host dye using an assist dopant such as rubrene. In any case, in order to obtain high luminance characteristics, it is preferable to dope those having a high fluorescence quantum yield.

If the amount of dopant material used is too large, a concentration quenching phenomenon will occur, so it is usually used at 30% by mass or less based on the host material. Preferably it is 20 mass% or less, More preferably, it is 10 mass% or less. As a method for doping the host material with the dopant material in the light emitting layer, it can be formed by a co-evaporation method with the host material. It is also possible to use it sandwiched between host materials. In this case, you may laminate | stack with host material as a dopant layer of one layer or two layers or more.

These dopant layers can form each layer alone, or may be used by mixing them. In addition, the dopant material may be polyvinyl chloride, polycarbonate, polystyrene, polystyrene sulfonic acid, poly (N-vinylcarbazole), poly (methyl) (meth) acrylate, polybutyl methacrylate, polyester, polysulfone, as a polymer binder. Solvent-soluble resins such as polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polysulfone, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane resin, phenol resin, xylene resin, petroleum resin, urea resin, melamine resin In addition, it can be used by being dissolved or dispersed in a curable resin such as an unsaturated polyester resin, an alkyd resin, an epoxy resin, or a silicone resin.

The method for forming a thin film used in the organic EL device according to the present invention is generally performed using the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene or the composition of the present invention. In particular, vacuum heating processes such as resistance heating deposition, electron beam deposition, sputtering, molecular lamination, solution processes such as casting, spin coating, dip coating, blade coating, wire bar coating, spray coating, etc., and inkjet Printing methods such as printing, screen printing, offset printing and letterpress printing, soft lithography methods such as microcontact printing methods, and a combination of these methods may be employed.

Resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, coating method by dissolving and dispersing in solvent or resin (spin coating, casting, dip coating, etc.), LB method, ink jet method, etc. are not particularly limited. . Usually, resistance heating vapor deposition is preferable in terms of characteristics. The thickness of each layer is not limited because it is set according to the resistance value of the light-emitting substance, but is selected from 0.5 to 5000 nm. The thickness is preferably 1 to 1000 nm, more preferably 5 to 500 nm.

The organic EL element of the present invention can be suitably used as a flat panel display. It can also be used as a flat backlight. In this case, either a light emitting colored light or a light emitting white light can be used. The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display board, a sign, and the like. In particular, it has been difficult to reduce the thickness of a conventional backlight for a liquid crystal display device, particularly a personal computer application, because it is made of a fluorescent lamp or a light guide plate. However, the backlight using the light emitting element of the present invention is thin, The above problem is solved because of its light weight. Similarly, it can be usefully used for illumination.

When the dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene of the present invention is used, an organic EL display device having high luminous efficiency and a long lifetime can be obtained. Further, by combining the thin film transistor element of the present invention, it becomes possible to supply an organic EL display device in which the applied voltage on / off phenomenon is electrically controlled with high accuracy at low cost.

(About photoelectric conversion elements)
Utilizing the organic semiconductor characteristics of the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention, a flexible, low-cost, and easy-to-use photoelectric conversion method Use as an element is expected. Among them, organic solar cell elements are advantageous in terms of flexibility and longevity because they do not use an electrolyte solution, unlike dye-sensitized solar cells. Conventionally, organic solar cells are combined with conductive polymers and fullerenes. Development of solar cells using thin film semiconductors is the mainstream, but power generation conversion efficiency is a problem.
In general, the structure of an organic solar cell element is the same as that of a silicon-based solar cell, in which a layer for generating power is sandwiched between an anode and a cathode, and holes and electrons generated by absorbing light are received by each electrode as a solar cell. Function. The power generation layer is composed of a P-type donor material, an N-type acceptor material, and other materials such as a buffer layer, and an organic solar cell is used in which an organic material is used.
The structures include Schottky junctions, heterojunctions, bulk heterojunctions, nanostructure junctions, hybrids, etc., but each material efficiently absorbs incident light and generates charges. It functions as a solar cell by separating, transporting and collecting electrons). Next, components in the solar cell element of the present invention will be described.

The anode and cathode in the solar cell element of the present invention are the same as those of the organic EL element described above. Since it is necessary to take in light efficiently, it is desirable to use an electrode having transparency in the absorption wavelength region of the power generation layer. Moreover, in order to have a favorable solar cell characteristic, it is preferable that sheet resistance is 20 ohms / square or less.
The power generation layer in the solar cell element of the present invention is a single layer forming an organic thin film containing at least the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention. Or it is formed of a plurality of layers. Although the structure shown above can be adopted, it is basically composed of a P-type donor material, an N-type acceptor material, and a buffer layer.

P-type donor materials include compounds that can transport holes in the same manner as the hole injection and hole transport layers described in the section of organic EL elements, polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Π-conjugated polymers such as polyaniline derivatives, and polymers having carbazole and other heterocyclic side chains. Examples of the low molecular compound include pentacene derivatives, rubrene derivatives, porphyrin derivatives, phthalocyanine derivatives, indigo derivatives, quinacridone derivatives, merocyanine derivatives, cyanine derivatives, squalium derivatives, benzoquinone derivatives, and the like.
The N-type acceptor layer basically has a compound capable of transporting electrons, such as the electron transport layer described in the section of the organic EL element, an oligomer or polymer having a skeleton of pyridine and its derivative, and a quinoline and its derivative as a skeleton. Polymers such as oligomers and polymers, polymers having benzophenanthrolines and derivatives thereof, cyanopolyphenylene vinylene derivatives (CN-PPV, etc.), fluorinated phthalocyanine derivatives, perylene derivatives, naphthalene derivatives, bathocuproine derivatives, C60 and C70 And low molecular weight materials such as fullerene derivatives such as PCBM.
Each of them preferably absorbs light efficiently and generates a charge, and the material used has a high extinction coefficient.

The dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene of the present invention can be particularly suitably used as a P-type donor material. The method for forming the thin film for the power generation layer of the organic solar cell of the present invention may be the same as the method described in the above-mentioned section of the organic EL element. Although the thickness of the thin film varies depending on the configuration of the solar cell, it is better to thicken it in order to absorb light sufficiently and prevent short circuiting. The thinner is suitable. Generally, about 10 to 5000 nm is suitable for the power generation layer.

(About light sensor and image sensor)
By utilizing the physical properties and semiconductor properties of the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention, it is expected to be used as an optical sensor or an image sensor. The Devices include solid-state image sensors as image sensors, and charge coupled devices (CCD) that have the function of converting video signals such as moving images and still images into digital signals. It is also expected to be used as various sensors that take advantage of the flexible functionality inherent to organic matter.

(About organic semiconductor laser elements)
Since dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention is a compound having organic semiconductor properties, it is expected to be used as an organic semiconductor laser device. The That is, a resonator structure is incorporated in an organic semiconductor element containing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention, and carriers are efficiently injected. If the density of the excited state can be sufficiently increased, it is expected that the light will be amplified and cause laser oscillation. Conventionally, only laser oscillation by optical excitation has been observed, and it is very difficult to inject high-density carriers necessary for laser oscillation by electrical excitation into an organic semiconductor element to generate a high-density excitation state. It has been proposed that by using the organic semiconductor element containing the dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene of the present invention, highly efficient light emission ( It is expected that electroluminescence will occur.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated still in detail, this invention is not limited to these examples. In Examples, “%” represents “% by mass” unless otherwise specified. Moreover, the reaction temperature described the internal temperature in a reaction system unless there is particular notice.
Various compounds obtained in the examples are subjected to various measurements such as mp (melting point), NMR (1H, 13C), IR (infrared absorption spectrum), MS (mass spectrometry spectrum), and elemental analysis as necessary. The structural formula was determined. The measuring equipment is as follows.
mp: Yanagimoto trace melting point measuring device MP-S3
NMR: JEOL Lambda 400 spectrometer
IR: Shimadzu Fourier Transform Infrared Spectrophotometer IR Prestige-21
MS spectrum: Shimadzu QP-5050A
Elemental analysis: Parkin Elmer2400 CHN type elemental analyzer

Example 1 Synthesis of dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene

(I) Synthesis of 3-methylthio-2-methoxyanthracene

To a solution of compound (1), 2-methoxyanthracene (15.0 g, 72 mmol) in THF (520 ml), a 1.67 M n-BuLi (86 ml, 144 mmol) hexane solution was added at 0 ° C. After stirring this at room temperature for 1 hour, dimethyl disulfide (13 ml, 150 mmol) was added at 0 ° C. and stirred at room temperature for 7 hours. The mixture was poured into water (100 ml), THF was concentrated with an evaporator, and the precipitated crystals were separated by filtration. Filtration and washing with water (100 ml) and then methanol (100 ml) gave 3-methylthio-2-methoxyanthracene (18.3 g, quantitative) as compound (2) as white crystals.
mp 176.5-177.5 ° C; ¹ H NMR (400 MHz, CDCl ₃ ) δ 2.58 (s, 3H), 4.03 (s, 3H), 7.16 (s, 1H), 7.39 (ddd, J = 8.2, 4.9, 1.9 Hz , 1H), 7.42 (ddd, J = 8.2, 4.9, 1.9 Hz, 1H), 7.55 (s, 1H), 7.92 (d, J = 9.5 Hz, 1H) 7.93 (d, J = 9.5 Hz, 1H), 8.22 (s, 1H), 8.24 (s, 1H); ¹³ C NMR (125 MHz, CDCl ₃ ) δ 14.7, 56.2, 103.4, 122.5, 124.3, 124.7, 124.9, 125.4, 127.9, 128.4, 128.9, 131.0, 131.0 , 131.7, 131.8, 154.6; EIMS (70 eV) m / z = 254 (M ⁺ ). Anal Calcd for C ₁₆ H ₁₄ OS: C, 75.55; H, 5.55%. Found: C, 75.26; H, 5.33% .

(II) Synthesis of 2-hydroxy-3-methylthioanthracene

A solution of BBr ₃ (ca.2M, 50 ml, 100 mmol) in dichloromethane (200 ml) in 3-methylthio-2-methoxyanthracene (14.5 g, 57 mmol) was added dropwise at −78 ° C. After stirring for 5 hours at room temperature, ice (about 50 g) was added at 0 ° C. The mixture was extracted with dichloromethane (200 ml × 3), washed with saturated brine (100 ml × 3), dried over MgSO ₄ and concentrated to give 2-hydroxy-3-methylthioanthracene (13.7 g, quantitative). Obtained as white crystals.
mp 175.6-176.5 ° C; ¹ H NMR (400 MHz, CDCl ₃ ) δ 2.49 (s, 3H), 6.54 (s, 1H), 7.31 (s, 1H), 7.39 (ddd, J = 10.7, 6.6, 1.4 Hz , 1H), 7.41 (s, 1H), 7.43 (ddd, J = 10.7, 6.6, 1.4 Hz, 1H), 7.91 (d, J = 8.8 Hz, 1H), 7.93 (dd, J = 8.8 1H), 8.14 (s, 1H), 8.22 (s, 1H), 8.30 (s, 1H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ 19.8, 107.8, 124.2, 125.0, 126.2, 126.2, 126.8, 128.0, 128.5, 128.6 , 130.8, 132.8, 133.0, 133.8, 151.7; IR (KBr) ν3510 cm ^-1 (OH); EIMS (70 eV) m / z = 240 (M ⁺ ); Anal Calcd for C ₁₅ H ₁₂ OS: C, 74.66 ; H, 4.72%. Found: C, 74.70; H, 4.84%.

(III) Synthesis of 3- (methylthio) anthracen-2-yl trifluoromethanesulfonate

To a solution of 2-hydroxy-3-methylthioanthracene (10.1 g, 42 mmol) and triethylamine (16.0 ml, 115 mmol) in dichloromethane (400 ml) was added trifluoromethanesulfonic anhydride (10.0 ml, 54.6 mmol) at 0 ° C. Added in. After stirring at room temperature for 42 hours and diluting with water (50 ml), dilute hydrochloric acid (4M, 100 ml) was added. This was extracted with dichloromethane (100 ml × 3), and the organic layers obtained by the extraction three times were combined, washed with saturated brine (100 ml × 3), dried over MgSO ₄ , concentrated, and 3- ( Methylthio) anthracen-2-yl trifluoromethanesulfonate (15.5 g, quantitative) was obtained as a yellow solid.
mp 105.5-106.0 ° C; ¹ H NMR (400 MHz, CDCl ₃ ) δ 2.63 (s, 3H), 7.50 (ddd, J = 9.6, 6.3, 1.8 Hz, 1H), 7.51 (ddd, J = 9.6, 6.3, 1.8 Hz, 1H), 7.78 (s, 1H), 7.88 (s, 1H), 7.97 (dd, J = 5.5, 2.0 Hz, 1H), 7.98 (dd, J = 5.5, 2.0 Hz, 1H), 8.34 ( s, 1H), 8.38 (s, 1H); ¹³ C NMR (125 MHz, CDCl ₃ ) δ 15.8, 119.0, (q, J = 319 Hz), 119.5, 125.4, 126.2, 126.4, 126.8, 127.1, 128.4 ( × 2), 129.0, 130.6, 131.0, 132.0, 132.9, 145.3; IR (KBr) ν 1429, 1207 cm ^-1 (-O-SO _2- ); EIMS (70 eV) m / z = 372 (M ⁺ ) ; Anal Calcd for C ₁₆ H ₁₁ F ₃ O ₃ S ₂ : C, 51.61; H, 2.98%. Found C, 51.57; H, 2.67%.

(IV) Synthesis of tributylstannylacetylene

Under a nitrogen atmosphere, tributyltin chloride (8.6 ml, 32 mmol) was added at 0 ° C. to a solution of 18 w% Na acetylene in xylene and mineral oil dispersion oil (10 ml, 8.5 g, 32 mmol) in THF (60 ml). After stirring for 17 hours at room temperature, the mixture was extracted with hexane and washed with brine. The organic layers were combined, dried over MgSO ₄ and concentrated. Distillation under reduced pressure (85-120 ° C., about 0.7 mmHg) gave tributylstannylacetylene (3.6 g, 34%) as a colorless oil.
¹ H-NMR (400 MHz, CDCl ₃ ) δ 0.91 (t, 9H, J = 8.0 Hz), 1.02 (t, 8H, J = 8.0 Hz), 1.35 (sextet, 6H, J = 8.0 Hz), 1.58 ( quintet, 6H, J = 8.0 Hz), 2.20 (s, 1H)

(V) Synthesis of 1,2-bis (tributylstannyl) ethylene (compound (3) -05)

Under a nitrogen atmosphere, azobisisobutyronitrile (100 mg, 0.60 mmol) was added to a toluene (20 ml) solution of tributylstannylacetylene (1.6 g, 5 mmol) and tributyltin hydride (1.3 ml, 5 mmol). It was. The mixture was stirred with heating at 90 ° C. for 17 hours, water (20 ml) was added, and the mixture was concentrated. The mixture was extracted with hexane, and the extract was washed with brine to give 1,2-bis (tributylstannyl) ethylene (compound (3) -05) (3.0 g, 90%) as a colorless oil. .
¹ H-NMR (400 MHz, CDCl ₃ ) δ 0.86-0.91 (multiplet, 15H), 1.31 (sextet, 6H, J = 8.0 Hz), 1.50 (quintet, 6H, J = 8.0 Hz), 6.88 (s, 2H )

(VI) Synthesis of trans-1,2-bis (3-methylthioanthracen-2-yl) ethane

Under a nitrogen atmosphere, 3- (methylthio) anthracen-2-yl trifluoromethanesulfonate (11.2 g, 30 mmol) and 1,2-bis (tributylstannyl) ethylene (compound (5) -05) (9 0.1 g, 15.0 mmol) in DMF (110 ml) was added Pd (PPh ₃ ) ₄ (1.2 g, 1.0 mmol, 3 mol%) and heated at 100 ° C. for 17 hours in the dark. After cooling and diluting with water, the precipitated crystals were filtered off, washed with water (100 ml) and ethanol (50 ml), and the compound (4) trans-1,2-bis (3-methylthioanthracene-2- Yl) ethane (3.9 g, 55%) was obtained as a yellow solid.
mp> 300 ° C; ¹ H NMR (400 MHz, CDCl ₃ ) δ 2.66 (s, 6H), 7.44 (dd, J = 5.0, 4.4 Hz, 4H), 7.75 (s, 2H), 7.78 (s, 2H) , 7.97 (d, J = 9.6 Hz, 2H), 7.98 (d, J = 9.6 Hz, 2H), 8.27 (s, 2H), 8.30 (s, 2H), 8.44 (s, 2H); ¹³ C NMR ( 100 MHz, CDCl ₃ ) δ 16.8, 124.2, 124.9, 125.7, 125.7, 126.0, 126.8, 126.9, 128.5, 128.6, 129.2, 130.6, 132.0, 132.8, 136.5, 147.3; IR (KBr) 1485, 1426, 1024, 957 , 862, 741 cm ^-1 ; EIMS (70 eV) m / z = 472 (M ⁺ ); Anal Calcd for C ₃₂ H ₂₄ S ₂ : C, 81.31; H, 5.12%. Found: C, 81.21; H, 4.90%.

(VII) Synthesis of diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene

Powdered iodine (59 g, 232 mmol) and trans-1,2-bis (3-methylthioanthracen-2-yl) ethane (3.8 g, 8.0 mmol) were added to acetic acid (250 ml), Heated to reflux for 11 hours. Excess acetic acid was removed by distillation, saturated aqueous NaHSO ₃ solution (200 ml) was added, and the mixture was stirred for 1 hr. The crystals were separated by filtration, washed with water (100 ml), acetone (100 ml), dichloromethane (100 ml) and washed with dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene (DATT). (3.8 g, quantitative) was obtained as a dark red solid. Sublimation purification is performed (about 400 ° C., 10 ⁻² Pa or less, under a nitrogen stream), recrystallization from chlorobenzene, and 50% yield of dianthra [2,3-b: 2 ′, 3′-f] thieno [3, 2-b] thiophene was obtained.
mp. > 300 ° C;
EIMS (70 eV) m / z = 440 (M ⁺ ). Anal Calcd for C ₃₀ H ₁₆ S ₂ : C, 81.78; H, 3.66%. Found: C, 81.38; H, 3.52%. Λmax = 550-570nm (When thin).

Comparative Example 1
According to the following reaction formula (4) following Patent Document 3, dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene was synthesized.
In the reaction formula (4-1), the target compound 3- (methylthio) anthracene-2-carbaldehyde was obtained in a yield of 80% as a mixture with an isomer having a methylthio group introduced at the 1-position. From identification by proton NMR, the target product (position 3) and by-product (position 1) were a mixture in a ratio of 4: 1. Using this mixture, a coupling reaction shown in the reaction formula (4-2) was performed, and the target product Trans-1,2-bis (3-methylthioanthracen-2-yl) ethane was purified to about 50% purity (proton NMR). The crude product contained in (identification) was obtained. Finally, a crude product containing dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene was obtained by a cyclization reaction shown in the reaction formula (4-3). These compounds were obtained by repeating sublimation purification and recrystallization. However, compared with the production method of the present application, the amount of intermediate impurities was very large, and the final total yield was greatly inferior. In addition, purification to remove them was performed. The process was very complicated.

As described above, according to the present invention, diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene can be synthesized easily and efficiently.

Next, a field effect transistor having a semiconductor layer made of dianthra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene will be described in detail.

Example 2 (Top Contact Field Effect Transistor)
An n-doped silicon wafer with 300 nm SiO ₂ thermal oxide film (surface resistance 0.02 Ω · cm or less) treated with octadecyltrichlorosilane was placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was 3.0 × 10 ^{−. It} exhausted until it became ³ Pa or less. The dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] obtained in Example 1 was applied to this electrode under the condition of a substrate temperature of about 100 ° C. by resistance heating vapor deposition. Thiophene was deposited to a thickness of 25 nm to form a semiconductor layer (2). Next, a shadow mask for electrode preparation is attached to this substrate, placed in a vacuum vapor deposition apparatus, evacuated until the degree of vacuum in the apparatus is 1.0 × 10 ⁻⁴ Pa or less, and gold electrode is formed by resistance heating vapor deposition That is, the source electrode (1) and the drain electrode (3) were vapor-deposited to a thickness of 40 nm to obtain a TC (top contact) type field effect transistor of the present invention.
In the field effect transistor of this example, the thermal oxide film in the n-doped silicon wafer with the thermal oxide film has the function of the insulating layer (4), and the n-doped silicon wafer is the substrate (6) and the gate electrode (5). )
The obtained field effect transistor was installed in a prober, and semiconductor characteristics were measured using a semiconductor parameter analyzer 4155C (manufactured by Agilent). For semiconductor characteristics, the gate voltage was scanned from 10 V to -100 V in 20 V steps, the drain voltage was scanned from 10 V to -100 V, and the drain current-drain voltage was measured. As a result, current saturation was observed, and from the obtained voltage-current curve, the device showed a p-type semiconductor, and the carrier mobility was 2.5 to 3.0 cm ² / Vs.

Next, an organic solar cell element having a semiconductor layer made of dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene will be described in detail.

Example 3
A glass substrate (manufactured by Tokyo Sanyo Vacuum Co., Ltd., 20Ω / □ or less) on which an ITO transparent conductive film was deposited to 115 nm was UV-ozone cleaned before device fabrication. This glass substrate was placed in a vacuum vapor deposition apparatus and evacuated until the degree of vacuum in the apparatus became 3.0 × 10 ⁻³ Pa or less. The dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained in Example 1 was deposited on this electrode to a thickness of 40 nm by resistance heating evaporation. A semiconductor layer was formed. Next, C60 was deposited to a thickness of 40 nm, and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was deposited to a thickness of 10 nm. Further, aluminum was deposited to a thickness of 100 nm through a shadow mask to form a cathode, and a φ2 mm round organic solar cell element was produced. The photoelectric conversion efficiency was measured at 100 mW / cm using an AM1.5 solar simulator. An organic solar cell with an open-circuit voltage of 0.42 V, a short-circuit current of 5.04 mA / cm ² , a fill factor of 0.56, and a conversion efficiency of 1.19% was obtained. FIG. 4 shows a JV characteristic diagram of the organic solar cell element of this example.

As described above, organic field effect transistors and organic thin-film solar cell elements were produced and their practicality was confirmed. Since dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained simply and efficiently according to the present invention has excellent characteristic values, organic field effect transistors, It can be said that it is a very useful compound as a material for various organic electronic devices such as organic light emitting diodes, organic light emitting transistors, organic solar cells, organic lasers, and organic optical sensors.

In FIG. 1, the same numbers are assigned to the same names.
1 source electrode 2 semiconductor layer 3 drain electrode 4 insulator layer 5 gate electrode 6 substrate 7 protective layer

Claims (11)

1. A process for producing diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene, comprising:
   A step of reacting a compound represented by the formula (1) with dimethyl sulfide to obtain a compound represented by the formula (2);
   Reacting a compound represented by the formula (2) with a tin compound represented by the formula (3) to obtain a compound represented by the formula (4); and a compound represented by the formula (4) Cyclization to obtain diantra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene;
   Including the above method.
   

   

   
   

   

   
   

   

   
   

   

   
   (In the formula, R ¹ and R ² represent a substituent, and Me represents a methyl group.)
2. An organic semiconductor material containing diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene obtained by the method according to claim 1.
3. An ink for producing a semiconductor device comprising diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene obtained by the method according to claim 1.
4. An organic semiconductor thin film containing diantra [2,3-b: 2 ', 3'-f] thieno [3,2-b] thiophene obtained by the method according to claim 1.
5. An organic electronic device having the organic semiconductor thin film according to claim 4.
6. The organic electronics device according to claim 5, which is a photoelectric conversion element, an organic EL element, an organic semiconductor laser element, a liquid crystal display element or a thin film transistor element.
7. The organic electronic device according to claim 5, which is a solar cell.
8. The organic electronic device according to claim 5, which is an optical sensor.
9. A process comprising: forming a semiconductor layer made of dianthra [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene obtained by the method according to claim 1 on a substrate. Item 6. A method for producing an organic electronic device according to Item 5.
10. The method for producing an organic electronic device according to claim 9, wherein the semiconductor layer is formed by a vapor deposition method.
11. The method for producing an organic electronic device according to claim 9, wherein the semiconductor layer is formed by applying the ink for producing a semiconductor device according to claim 3.

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