JP6917106B2 - Condensed polycyclic aromatic compounds and their uses - Google Patents

Description

The present invention relates to a condensed polycyclic aromatic compound, an organic semiconductor material and an organic semiconductor composition containing the compound, an organic thin film containing the organic semiconductor material, a method for producing the organic thin film, and an organic semiconductor device having the organic thin film. Regarding.

In recent years, research and development on organic semiconductor devices (printed electronics) using printing technology have been actively carried out because of the significant efficiency of the device manufacturing process and the ability to manufacture flexible devices using plastic materials. There is.
It goes without saying that the organic semiconductor material used in such a technique has good semiconductor properties (carrier mobility, etc.), and is organic in order to prepare an organic semiconductor solution (ink) used in the printing technique. It is required to be soluble in a solvent.

Examples of the low molecular weight semiconductor material soluble in an organic solvent include a benzodithiophene (BDT) skeleton, a benzothioenobenzothiophene (hereinafter, abbreviated as “BTBT”) skeleton, and a dinaphthodithiophene (hereinafter, appropriately abbreviated as “DNTT”). A compound in which an alkyl chain is introduced into the molecular major axis of a condensed polycyclic aromatic compound containing a sulfur atom or a selenium atom having a skeleton is known (see Patent Documents 1 to 3 and Non-Patent Documents 1 to 3). ..

The alkyl derivative of BTBT has the solvent solubility necessary for preparing an organic semiconductor solution capable of forming a semiconductor thin film in a printing process, but causes a phase transition at a low temperature because the number of condensed rings relative to the alkyl chain length is relatively small. It is known that the semiconductor characteristics of the obtained organic semiconductor device are easily deteriorated (see Non-Patent Document 4). On the other hand, when an alkyl derivative of DNTT having more fused rings than BTBT is used, the obtained organic semiconductor device improves the deterioration of semiconductor characteristics due to the phase transition at low temperature, but the semiconductor is used in the printing process. The solvent solubility required for the preparation of an organic semiconductor solution capable of forming a thin film is insufficient, and the solvent solubility required for the preparation of an organic semiconductor solution capable of forming a semiconductor thin film in a printing process even if the number of fused rings is increased. It is required to develop an organic semiconductor material (organic semiconductor compound) having good semiconductor properties in the obtained organic semiconductor device.

Patent Documents 4 and 5 describe benzothienonaphthophene (hereinafter, abbreviated as "BTNT" as appropriate) derivatives having a structure in which the number of condensed rings is intermediate between BTBT and DNTT. The BTNT skeleton has a structure in which the number of fused rings is intermediate between BTBT and DNT, and it can be expected to ensure both solubility and semiconductor characteristics. However, all the derivatives described in these documents have carrier mobility. The ^{mobility is about 10 -1} cm ² / Vs, and good semiconductor characteristics sufficient for practical use have not been obtained.

Japanese Patent No. 5187737 Japanese Patent No. 4581062 Japanese Patent No. 5477978 Japanese Patent No. 5415723 WO2013 / 039842

Chem. Lett. , 2008,37,284. J. Am. Chem. Soc. , 2007, 129, 15732. Adv. Matter. , 2011, 23, 1222. Nat. Commun. , 2015, 6, 6828.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an organic semiconductor solution having solvent solubility necessary for preparing an organic semiconductor solution capable of forming a semiconductor thin film in a printing process. It is an object of the present invention to provide a novel organic semiconductor compound in which the organic semiconductor device obtained by using the device exhibits excellent semiconductor characteristics.

As a result of diligent studies to solve the above problems, the present inventors have found that the above problems can be solved by using a condensed polycyclic aromatic compound in which a substituent having a specific structure is introduced into the BTNT skeleton. rice field.
That is, the present invention
[1] The following formula (1) or (2)

(In formulas (1) and (2), _one of R 1 and R ₂ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and the other represents a hydrogen atom. _{One of R 3} and R ₄ is represented by the following formula (3) or (4).

(In formulas (3) and (4), p, q and r each represent an integer of 1 to 20, where X represents an oxygen atom or a sulfur atom, respectively. R ₅ is an alkyl group having 1 to 20 carbon atoms. , Represents an aromatic hydrocarbon group or a heterocyclic group.), And the other represents a hydrogen atom. ), Condensed polycyclic aromatic compounds,
(2) R ₁ and R ₄ are hydrogen atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and R ₃ is the formula (3) or The condensed polycyclic aromatic compound according to the previous item (1), which is a substituent represented by (4).
(3) R ₁ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, R ₂ and R ₃ are hydrogen atoms, and R ₄ is the formula (3) or The condensed polycyclic aromatic compound according to the previous item (1), which is a substituent represented by (4).
(4) The condensed polycyclic aromatic compound according to any one of the above items (1) to (3), wherein either _{R 3} or R _{4 is a substituent represented by the formula (3).}
(5) The condensed polycyclic aromatic compound according to (4) above, wherein p is an integer of 6 to 14.
(6) The condensed polycyclic aromatic compound according to any one of the above items (1) to (3), wherein any one of _{R 3} and R _{4 is a substituent represented by the formula (4).}
(7) The condensed polycyclic aromatic compound according to the previous item (6), wherein q is an integer of 6 to 14 and r is an integer of 1 to 4.
(8) R ₅ is a condensed polycyclic aromatic compound according to any one of (1) to (7) is an alkyl group of 1 to 4 carbon atoms,
(9) The condensed polycyclic aromatic compound according to any one of (1) to (8) above, which does not exhibit liquid crystallinity.
(10) An organic semiconductor material containing the condensed polycyclic aromatic compound according to any one of (1) to (9) above.
(11) The organic semiconductor composition containing the organic semiconductor material and the organic solvent according to the previous item (10).
(12) An organic thin film containing the organic semiconductor material according to (10) above.
(13) The organic semiconductor device having the organic thin film according to the previous item (12).
(14) The step of applying or printing the organic semiconductor device according to the previous item (13), which is an organic transistor, and (15) the organic semiconductor composition according to the previous item (11) on a substrate, and coating or printing on the substrate. A method for producing a thin film, which comprises a step of removing an organic solvent from an organic semiconductor composition.
It is about.

Since the condensed polycyclic aromatic compound of the present invention has good solvent solubility, it is suitably used when producing an organic semiconductor device in a printing process, and an organic semiconductor device having an organic thin film obtained by using the compound. Expresses good semiconductor properties.

It is the schematic which shows the structural aspect example of the organic transistor of this invention. It is the schematic of the process for manufacturing one aspect example of the organic transistor of this invention.

The present invention will be described below.
The condensed polycyclic aromatic compound of the present invention has a structure represented by the above formula (1) or (2).
In formulas (1) and (2), _one of R 1 and R ₂ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and the other represents a hydrogen atom.

_{The alkyl group having 1 to 20 carbon atoms represented by R 1} or R _{2 of the} formulas (1) and (2) is not limited to any of the linear, branched chain and alicyclic type.
Specific examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and an n-nonyl group. , N-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecil group. And n-eikosyl group and the like.
Specific examples of the branched alkyl group include iso-propyl group, iso-butyl group, t-butyl group, iso-pentyl group, t-pentyl group, sec-pentyl group, iso-hexyl group, sec-heptyl group and Examples thereof include a sec-nonyl group.
Specific examples of the alicyclic alkyl group include a cyclohexyl group, a cyclopentyl group, an adamantyl group, a norbornyl group and the like.
_{The alkyl group represented by R 1} or R _{2 of the} formulas (1) and (2) is preferably a straight chain or branched chain alkyl group, and more preferably a straight chain alkyl group. The alkyl group represented by R ₁ or R ₂ preferably has 4 to 12 carbon atoms, and more preferably 6 to 12 carbon atoms.

_{Specific examples of the aromatic hydrocarbon group represented by R 1} or R _{2 of the} formulas (1) and (2) include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a benzopyrenyl group and the like, and phenyl. It is preferably a group or a naphthyl group, more preferably a phenyl group.
_{The aromatic hydrocarbon group represented by R 1} or R _{2 of the} formulas (1) and (2) may have an alkyl group as a substituent, and the alkyl group which may have as the substituent is a straight chain. , A branched chain or an alicyclic type, and specific examples thereof include the same alkyl groups represented by _{R 1} or R _{2 of the formulas (1) and (2).
The alkyl group that the aromatic hydrocarbon group represented by R 1} or R _{2 of the} formulas (1) and (2) may have as a substituent is preferably a linear or branched alkyl group. It is more preferably a straight chain alkyl group. Further, the _{aromatic hydrocarbon group represented by R 1} or R ₂ may have as a substituent, the alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. It is more preferably to 6.

_{Specific examples of the heterocyclic group represented by R 1} or R _{2 of the} formulas (1) and (2) include a pyridyl group, a pyrazil group, a pyrimidyl group, a quinolyl group, an isoquinolyl group, a pyrrolyl group, an indrenyl group, an imidazolyl group and a carbazolyl group. Examples thereof include a group, a thienyl group, a frill group, a pyranyl group, a pyridonyl group, a benzoquinolyl group, an anthraquinolyl group, a benzothienyl group, a benzofuryl group and a thienotienyl group, and the group may be a pyridyl group, a thienyl group, a benzothienyl group or a thienotienyl group. It is more preferably a pyridyl group, a thienyl group or a benzothienyl group, and even more preferably a pyridyl group or a thienyl group.
_{The aromatic hydrocarbon group represented by R 1} or R _{2 of the} formulas (1) and (2) may have an alkyl group as a substituent, and a specific example of the alkyl group which may have as the substituent. Examples thereof include the same alkyl groups represented by _{R 1} or R ₂ of the formulas (1) and (2).
The alkyl group represented by _{R 1} or R ₂ of the formulas (1) and (2) may have as a substituent is represented by _{R 1} or R _{2 of the formulas (1) and (2).} Examples thereof include the same alkyl groups that the aromatic hydrocarbon group may have as a substituent, and the same are preferable ones.

In formulas (1) and (2), one of R ₃ and R ₄ represents a substituent represented by the above formula (3) or (4), and the other represents a hydrogen atom.
In the formula (3) and (4), p, q and r represents an integer of 1 to 20, X each independently represents an oxygen atom or a sulfur atom, R ₅ is an alkyl group having 1 to 20 carbon atoms, Represents an aromatic hydrocarbon group or a heterocyclic group.

p represents the carbon number of the alkylene group in the substituent represented by the formula (3), and is preferably an integer of 4 to 16, more preferably an integer of 6 to 14, and 8 to 12 It is more preferably an integer of.
Each of q and r indicates the number of carbon atoms of the alkylene group in the substituent represented by the formula (4), and q is preferably an integer of 4 to 16, and more preferably an integer of 6 to 14. It is preferable that it is an integer of 8 to 12, r is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, and even more preferably an integer of 1 to 4. ..
Further, the total q + r of q and r is preferably 2 to 25, more preferably 2 to 20, and even more preferably 2 to 15.

Equation (3) and an alkyl group having 1 to 20 carbon atoms R ₅ represents the formula (4) is not limited to any linear, branched or alicyclic, and specific examples thereof, the formula (1) And the same as the alkyl group represented by _{R 1} or R _{2 in} (2).
Equation (3) and an alkyl group having 1 to 20 carbon atoms R ₅ represents the formula (4) may have as a substituent an aromatic hydrocarbon group or heterocyclic group may be in organic Examples of the substituent include the same aromatic hydrocarbon groups and heterocyclic groups represented by _{R 1} or R ₂ of the formulas (1) and (2).
The alkyl group of the formula (3) and (4) the R ₅ is a C 1 -C 20 represents preferably an alkyl group of straight or branched chain, more preferably a straight chain alkyl group. Further, the carbon number of the alkyl group of R ₅ 1 to 20 carbon atoms represented by the formula (3) and (4), is preferably from 1 to 10, more preferably from 1 to 8, 1 to It is more preferably 6 and particularly preferably 1 to 4.

As the condensed polycyclic aromatic compound represented by the formula (1) or (2), a compound satisfying the conditions of (i) or (ii) described below is particularly preferable.
(I) R ₁ and R ₄ are hydrogen atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and R ₃ is the formula (3) or Condensed polycyclic aromatic compounds which are substituents represented by (4) are preferable, and the R _{1 to} R ₄ (and p, q, r, X and R _{5 in the formulas (3) and (4)) are preferable.} However, the above-mentioned preferable or particularly preferable condensed polycyclic aromatic compound is more preferable.
(Ii) R ₁ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, R ₂ and R ₃ are hydrogen atoms, and R ₄ is the formula (3) or. Condensed polycyclic aromatic compounds which are substituents represented by (4) are preferable, and the R _{1 to} R ₄ (and p, q, r, X and R _{5 in the formulas (3) and (4)) are preferable.} However, the above-mentioned preferable or particularly preferable condensed polycyclic aromatic compound is more preferable.

The condensed polycyclic aromatic compound represented by the formula (1) or the formula (2) of the present invention is, for example, J.I. Am. Chem. Soc. , 2013, 135, 13900. It can be synthesized by using a raw material having a corresponding substituent based on the synthesis flow described in 1.

Specific examples of the condensed polycyclic aromatic compound represented by the formula (1) or the formula (2) of the present invention are shown below, but the present invention is not limited thereto.

Further, the condensed polycyclic aromatic compound represented by the formula (1) or (2) is required to be soluble in an organic solvent. The organic solvent can be used without particular limitation as long as it can dissolve the condensed polycyclic aromatic compound represented by the formula (1) or (2), but is a non-halogen solvent in a practical sense. It is preferable to have. Further, when the stability of the solution obtained by dissolving the condensed polycyclic aromatic compound represented by the formula (1) or (2) in a solvent is taken into consideration, it is represented by the formula (1) or (2) at room temperature. It is required that the solubility of the condensed polycyclic aromatic compound is higher than a certain level. The solubility at 25 ° C. is usually 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably 0.3% by mass or more. Further, regarding the stability of the solution, it is preferable that no crystals are precipitated even after 24 hours have passed after the dissolution, and it is more preferable that the solution is completely dissolved even after 1 week has passed after the dissolution.

As the organic solvent, halogen-based solvents such as chloroform, dichloromethane, chlorobenzene and dichlorobenzene can be used, but non-halogen solvents are preferable, and aromatic carbonization such as benzene, toluene, xylene, mesitylene, ethylbenzene, tetrahydronaphthalene and cyclohexylbenzene is preferable. Hydrogens, diethyl ethers, tetrahydrofurans, anisole, ethers such as phenetol and butoxybenzene, amides such as dimethylacetamide, dimethylformamide and N-methylpyrrolidone, acetone, methylethylketone, methylisobutylketone, cyclopentanone and cyclohexanone. Ketones, acetonitrile, nitriles such as propionitrile and benzonitrile, alcohols such as methanol, ethanol, isopropanol, butanol and cyclohexanol, esters such as ethyl acetate, butyl acetate, ethyl benzoate and diethyl carbonate, hexane, Hydrocarbons such as octane, decane, cyclohexane and decalin can be used.

The organic semiconductor material of the present invention contains a condensed polycyclic aromatic compound represented by the formula (1) or (2).
The content of the condensed polycyclic aromatic compound represented by the formula (1) or (2) in the organic semiconductor material is not particularly limited, but is usually about 50 to 100% by mass in the organic semiconductor material.

The organic semiconductor composition of the present invention is obtained by dissolving or dispersing an organic semiconductor material containing a condensed polycyclic aromatic compound represented by the formula (1) or (2) in the above solvent. As the solvent that can be used, the above solvent may be used as a single organic solvent, or a plurality of organic solvents may be mixed and used.
The content of the condensed polycyclic aromatic compound represented by the formula (1) or (2) in the organic semiconductor composition varies depending on the type of solvent and the thickness of the thin film to be prepared, but is usually 0.01 with respect to the solvent. It is from 5% by mass, preferably 0.1 to 5% by mass, and more preferably 0.3 to 5% by mass. Further, in the organic semiconductor composition of the present invention, the organic semiconductor material of the present invention may be dissolved or dispersed in the above solvent, but it is preferably dissolved as a uniform solution.

The organic semiconductor material of the present invention improves the characteristics of the organic semiconductor device and / or imparts other characteristics in addition to the condensed polycyclic aromatic compound represented by the above formula (1) or (2) and the organic solvent. If necessary, other additives may be contained for the purpose of the above, and the type of the additive is not particularly limited as long as it does not impair the function as a semiconductor. For example, in addition to semiconductor materials and insulating materials having a structure other than the formula (1) or (2) of the present invention, surfactants, thickeners, carrier injections and carrier amounts for controlling rheology are adjusted. A dopant for this purpose is given as an example. These are preferably those that do not impair the stability of the composition, and may be high molecular weight or low molecular weight. The content of these additives varies depending on the purpose and cannot be unequivocally determined, but it is preferably smaller than the content of the condensed polycyclic aromatic compound represented by the formula (1) or (2).

The organic thin film of the present invention can be obtained by using an organic semiconductor material containing a condensed polycyclic aromatic compound represented by the formula (1) or (2). The film thickness of the thin film varies depending on the application, but is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

Examples of the method for forming the organic thin film include a dry process such as a thin film deposition method and various solution processes, but it is preferable to form the organic thin film by a solution process. Examples of the solution process include spin coating method, drop casting method, dip coating method, spray method, flexo printing, letterpress printing method such as resin letterpress printing, offset printing method, dry offset printing method, and flat plate printing method such as pad printing method. , Recessed printing method such as gravure printing method, screen printing method, copy printing method, stencil printing method such as lingraph printing method, inkjet printing method, micro contact printing method, etc., and a method in which a plurality of these methods are combined can be mentioned. .. When forming a film by a solution process, it is preferable to form a thin film by evaporating the solvent after the above coating and printing.

The condensed polycyclic aromatic compound represented by the formula (1) or the formula (2) is suitable as a material for an organic thin film of an organic semiconductor device such as an organic EL element, an organic solar cell element, an organic photoelectric conversion element and an organic transistor element. Used. As an example, the organic transistor will be described in detail.

An organic transistor has two electrodes (source electrode and drain electrode) in contact with an organic semiconductor, and the current flowing between the electrodes is controlled by a voltage applied to another electrode called a gate electrode.
In general, an organic transistor device often uses a structure in which a gate electrode is insulated with an insulating film (Metal-InsuIator-Semiconductor MIS structure). A structure in which a metal oxide film is used as an insulating film is called a MOS structure. In addition, there is a structure in which a gate electrode is formed via a Schottky barrier (that is, a MES structure), but in the case of an organic transistor, a MIS structure is often used.

Hereinafter, the organic transistor will be described in more detail with reference to some examples of the organic transistor device shown in FIG. 1, but the present invention is not limited to these structures.
In each embodiment in FIG. 1, 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. The arrangement of each layer and electrodes can be appropriately selected depending on the application of the device. A to D and F are called horizontal transistors because current flows in the direction parallel to the substrate. A is called a bottom contact bottom gate structure, and B is called a top contact bottom gate structure. Further, C has a source and drain electrodes and an insulator layer provided on the semiconductor, and a gate electrode is further formed on the source and drain electrodes, which is called a top contact top gate structure. D has a structure called a top & bottom contact bottom gate type transistor. F has a bottom contact top gate structure. E is a schematic diagram of a transistor having a vertical structure, that is, a static induction transistor (SIT). In this SIT, since the current flow spreads in a plane, a large number of carriers can move at one time. Moreover, 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 applications such as passing a large current and performing high-speed switching. Although the substrate is not shown in E in FIG. 1, a substrate is usually provided outside the source or drain electrodes represented by 1 and 3 in FIG. 1E.

Next, each component in each embodiment will be described.
The substrate 6 needs to be able to hold each layer formed on the substrate 6 without peeling. For example, insulating materials such as resin plates, films, paper, glass, quartz, and ceramics; insulating layers formed by coating on conductive substrates such as metals and alloys; materials made up of various combinations of resins and inorganic materials; Etc. can be used. Examples of the resin film that can be used include polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyamide, polyimide, polycarbonate, cellulose triacetate, and polyetherimide. By using a resin film or paper, the device can be made flexible, which makes it flexible, 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, metals such as platinum, gold, silver, aluminum, chromium, tungsten, tantalum, nickel, cobalt, copper, iron, lead, tin, titanium, indium, palladium, molybdenum, magnesium, calcium, barium, lithium, potassium and sodium. 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, polydiaacetylene; silicon, germanium, Semiconductors such as gallium arsenic; carbon materials such as carbon black, fullerene, carbon nanotubes, graphite and graphene; and the like can be used. Further, the conductive polymer compound and the semiconductor may be doped. Examples of the dopant include inorganic acids such as hydrochloric acid and sulfuric acid; organic acids having acidic functional groups such as sulfonic _{acid; Lewis acids such as PF 5} , AsF ₅ , FeCl ₃ ; halogen atoms such as iodine; lithium, sodium and potassium. Metal atoms such as; etc. Boron, phosphorus, arsenic and the like are also widely used as dopants for inorganic semiconductors such as silicon.

Further, a conductive composite material in which carbon black, metal particles, etc. are dispersed in the above-mentioned dopant is also used. For the source electrode 1 and the drain electrode 3 that come into direct contact with the semiconductor, it is important to select an appropriate work function or surface treatment in order to reduce the contact resistance.
In addition, the distance between the source electrode and the drain electrode (channel length) is an important factor that determines the characteristics of the device, and an appropriate channel length is required. If the channel length is short, the amount of current that can be taken out increases, but short-channel effects such as the influence of contact resistance may occur, and the semiconductor characteristics may deteriorate. The channel length is usually 0.01 to 300 μm, preferably 0.1 to 100 μm. The width (channel width) between the source and drain electrodes is usually 10 to 5000 μm, preferably 40 to 2000 μm. In addition, it is possible to form a longer channel width by making the electrode structure a comb-shaped structure, etc., and it is necessary to make this channel width an appropriate length depending on the required amount of current and the structure of the device. be.

Next, the structures (shapes) of the source electrode and the drain electrode will be described. The structures of the source electrode and the drain electrode may be the same or different.

In the case of a bottom contact structure, it is generally preferable that each electrode is manufactured by a lithography method, and each electrode is formed in a rectangular parallelepiped. Recently, the printing accuracy of various printing methods has been improved, and it has become possible to manufacture electrodes with high accuracy by using techniques such as inkjet printing, gravure printing, and screen printing. In the case of a top contact structure having electrodes on a semiconductor, vapor deposition can be performed using a shadow mask or the like. It has become possible to directly print and form an electrode pattern using a technique such as inkjet. The length of the electrode is the same as the channel width described above. The width of the electrode is not particularly specified, but it is preferably short in order to reduce the area of the device within the range in which 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 0.5 to 1000 nm, preferably 1 to 500 nm, and more preferably 5 to 200 nm. Wiring is connected to each of the electrodes 1, 3 and 5, but the wiring is also made of almost the same material as the electrodes.

As the insulator layer 4, a material having an insulating property is used. For example, polyparaxylylene, polyacrylate, polymethylmethacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, polysiloxane, fluororesin, epoxy resin, phenol resin, etc. polymers and copolymers combination thereof; silicon oxide, aluminum oxide, titanium oxide, metal oxides such as tantalum oxide; SrTiO _3, the ferroelectric metal oxides such as BaTiO _3; silicon nitride, nitride such as aluminum nitride Dioxides such as substances, sulfides, and fluorides; or polymers in which particles of these dielectrics are dispersed; and the like can be used. As the insulator layer, one having high electrical insulation characteristics can be preferably used in order to reduce the leakage current. As a result, the film thickness can be reduced, the insulation capacity can be increased, and the current that can be taken out increases. Further, in order to improve the mobility of the semiconductor, it is preferable that the surface energy of the surface of the insulator layer is lowered and the film is smooth without unevenness. Therefore, a self-assembled monolayer or a two-layer insulator layer may be formed. The film thickness of the insulator layer 4 varies depending on the material, but is usually 1 nm to 100 μm, preferably 5 nm to 50 μm, and more preferably 5 nm to 10 μm.

As the material of the semiconductor layer 2, an organic semiconductor material containing at least one kind of condensed polycyclic aromatic compound represented by the above formula (1) or (2) can be used. The organic thin film containing the condensed polycyclic aromatic compound represented by the formula (1) or (2) can be formed into the semiconductor layer 2 by using the method for forming the thin film shown above.
A plurality of layers may be formed as the semiconductor layer, but a single-layer structure is more preferable. The film thickness of the semiconductor layer 2 is preferably as thin as long as it does not lose the necessary functions. In horizontal organic transistors as shown in A, B, and D, the characteristics of the device do not depend on the film thickness if the film thickness is equal to or greater than a predetermined value, but the leakage current often increases as the film thickness increases. Because. The film thickness of the semiconductor layer for exhibiting the required function is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

For the organic transistor, for example, another layer can be provided 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 device, if necessary. For example, when a protective layer is formed directly on the organic semiconductor layer or through another layer, the influence of outside air such as humidity can be reduced. In addition, there is an advantage that the electrical characteristics can be stabilized, such as increasing the on / off ratio of the organic transistor device.
The material of the protective layer is not particularly limited, but for example, a film made of an epoxy resin, an acrylic resin such as polymethylmethacrylate, and various resins such as polyurethane, polyimide, polyvinyl alcohol, fluororesin, and polyolefin; silicon oxide, aluminum oxide, and the like. Inorganic oxide films such as silicon nitride; and films made of dielectrics such as nitride films; etc. are preferably used, and in particular, resins (polymers) having low oxygen and moisture permeability and water absorption are preferable. Gas barrier protective materials developed for organic EL displays can also be used. The film thickness of the protective layer can be selected as desired depending on the purpose, but is usually 100 nm to 1 mm.

Further, by performing surface modification or surface treatment on the substrate or insulator layer on which the organic semiconductor layer is laminated in advance, it is possible to improve the characteristics as an organic transistor device. For example, by adjusting the degree of hydrophilicity / hydrophobicity of the substrate surface, the film quality and film forming property of the film formed on the substrate surface can be improved. In particular, the characteristics of organic semiconductor materials may change significantly depending on the state of the film such as the orientation of molecules. Therefore, by surface-treating the substrate, the insulator layer, etc., the molecular orientation of the interface portion with the organic semiconductor layer to be subsequently formed is controlled, or the trap portion on the substrate or the insulator layer is reduced. Therefore, it is considered that the characteristics such as carrier mobility are improved.
The trap site refers to a functional group such as a hydroxyl group existing on the untreated substrate, and in the presence of such a functional group, electrons are attracted to the functional group, and as a result, the carrier mobility is lowered. .. Therefore, reducing the trap portion is often effective for improving characteristics such as carrier mobility.

Examples of the surface treatment for improving the characteristics as described above include self-assembling monolayer treatment with hexamethyldisilazane, octyltrichlorosilane, octadecyltrichlorosilane, etc., surface treatment with polymers, hydrochloric acid, sulfuric acid, acetic acid, etc. Acid treatment with sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc., ozone treatment, fluorination treatment, plasma treatment with oxygen, argon, etc., Langmuir Brodget film formation treatment, and other insulators. And semiconductor thin film formation treatment, mechanical treatment, electrical treatment such as corona discharge, rubbing treatment using fibers and the like, and a combination of these can also be performed.
In these aspects, 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, the above-mentioned vacuum process and solution process can be appropriately adopted.

Next, a method for manufacturing the organic transistor device according to the present invention will be described below with reference to FIG. 2 by taking the top contact bottom gate type organic transistor shown in the embodiment B of FIG. 1 as an example. This manufacturing method can be similarly applied to the organic transistors and the like of the other aspects described above.

(About the substrate and substrate processing of organic transistors)
The organic transistor of the present invention is manufactured by providing various necessary layers and electrodes on the substrate 6 (see FIG. 2 (1)). As the substrate, the one described above can be used. It is also possible to perform the above-mentioned surface treatment on this substrate. The thickness of the substrate 6 is preferably thin as long as it does not interfere with the required functions. Although it depends on the material, it is usually 1 μm to 10 mm, preferably 5 μm to 5 mm. Further, if necessary, the substrate can be provided with the function of an electrode.

(About the formation of gate electrodes)
The gate electrode 5 is formed on the substrate 6 (see FIG. 2 (2)). As the electrode material, the one described above is used. As a method for forming the electrode film, various methods can be used, and 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 adopted. It is preferable to perform patterning as necessary so as to obtain a desired shape at the time of film formation 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. In addition, a vapor deposition method using a shadow mask, a sputtering method, an inkjet printing method, a printing method such as screen printing, offset printing, letterpress printing, a soft lithography method such as a microcontact printing method, and a method combining a plurality of these methods are used. However, it is also possible to pattern. 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, and more preferably 1 nm to 3 μm. Further, when the gate electrode and the substrate are also used, the film thickness may be larger than the above.

(About the formation of the insulator layer)
An insulator layer 4 is formed on the gate electrode 5 (see FIG. 2 (3)). As the insulator material, the material described above is used. Various methods can be used to form the insulator layer 4. For example, application methods such as spin coating, spray coating, dip coating, casting, bar coating, blade coating, screen printing, offset printing, printing methods such as inkjet, vacuum deposition method, molecular beam epitaxial growth method, ion cluster beam method, ion play. Examples thereof include a dry process method such as a ting method, a sputtering method, an atmospheric pressure plasma method, and a CVD method. In addition, a method of forming an oxide film on a metal by a thermal oxidation method such as a sol-gel method, alumite on aluminum, or silicon oxide on silicon is adopted. In the portion where the insulator layer and the semiconductor layer are in contact with each other, a molecule constituting a semiconductor at the interface between the two layers, for example, a molecule of a condensed polycyclic aromatic compound represented by the above formula (1) or (2) is favorably used. A predetermined surface treatment can also be applied to the insulator layer for orientation. As the surface treatment method, the same method as the surface treatment of the substrate can be used. The film thickness of the insulator layer 4 is preferably as thin as possible because the amount of electricity taken out can be increased by increasing its electric capacity. At this time, if the film becomes thin, the leakage current increases, so it is preferable that the film is thin as long as its function is not impaired. It is usually 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, and more preferably 5 nm to 10 μm.

(About the formation of organic semiconductor layers)
The organic semiconductor material containing the condensed polycyclic aromatic compound represented by the above formula (1) or (2) of the present invention is used for forming an organic semiconductor layer (see FIG. 2 (4)). Various methods can be used to form the organic semiconductor layer. Specifically, a coating method such as a dip coating method, a die coater method, a roll coater method, a bar coater method, or a spin coating method, a forming method by a solution process such as an inkjet method, a screen printing method, an offset printing method, or a microcontact printing method. Can be mentioned.

A method of forming an organic semiconductor layer by forming a film by a solution process will be described. A composition obtained by dissolving a condensed polycyclic aromatic compound represented by the formula (1) or (2) of the present invention in a solvent or the like and further adding an additive or the like if necessary is applied to a substrate (insulator layer, source electrode). And the exposed part between the drain electrodes). The coating method includes spin coating method, drop casting method, dip coating method, spray method, flexo printing, letterpress printing method such as resin letterpress printing, offset printing method, dry offset printing method, and flat plate printing method such as pad printing method. , Recessed printing method such as gravure printing method, silk screen printing method, copy printing method, stencil printing method such as lingraph printing method, inkjet printing method, micro contact printing method, etc. Will be printed.
Further, as a method similar to the coating method, the Langmuir project method in which the monomolecular film of the organic semiconductor layer produced by dropping the above composition on the water surface is transferred to a substrate and laminated, and two liquid crystal or liquid-state materials are used. It is also possible to adopt a method of sandwiching between the substrates and introducing it between the substrates by capillarity.

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. Therefore, it is preferable to carefully select the temperature of the substrate and the composition. The substrate temperature is usually 0 to 200 ° C, preferably 10 to 120 ° C, and more preferably 15 to 100 ° C. Care must be taken as it largely depends on the solvent in the composition used.
The film thickness of the organic semiconductor layer produced by this method is preferably thin as long as the function is not impaired. There is a concern that the leakage current will increase as the film thickness increases. The film thickness of the organic semiconductor layer is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

The characteristics of the organic semiconductor layer thus formed (see FIG. 2 (4)) can be further improved by post-treatment. For example, heat treatment improves and stabilizes the characteristics of organic semiconductors because the distortion in the film generated during film formation is alleviated, pinholes are reduced, and the arrangement and orientation in the film can be controlled. Can be achieved. It is effective to perform this heat treatment at the time of producing the organic transistor of the present invention in order to improve the characteristics. The 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 about 150 ° C. from room temperature, preferably 40 to 120 ° C., and more preferably 45 to 100 ° C. The heat treatment time at this time is not particularly limited, but is usually about 10 seconds to 24 hours, preferably about 30 seconds to 3 hours. The atmosphere at that time may be in the atmosphere, but it may also be in an inert atmosphere such as nitrogen or argon. In addition, the film shape can be controlled by solvent vapor.

In addition, as another post-treatment method for the organic semiconductor layer, treatment is performed using an oxidizing or reducing gas such as oxygen or hydrogen, or an oxidizing or reducing liquid, thereby inducing a change in characteristics due to oxidation or reduction. You can also do it. This can be used, for example, for the purpose of increasing or decreasing the carrier density in the membrane.

Further, in a method called doping, the 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, acids such as oxygen, hydrogen, hydrochloric acid, sulfuric acid, sulfonic acid _{; Lewis acids such as PF 5} , AsF ₅ , FeCl ₃ ; halogen atoms such as iodine; metal atoms such as sodium and potassium; tetrathiafluvalene (TTF) and Donor compounds such as phthalocyanine can be doped. This can be achieved by contacting the organic semiconductor layer with these gases, immersing them in a solution, or subjecting them to an electrochemical doping treatment. These dopings are added at the time of synthesizing the organic semiconductor compound or added to the composition in the process of producing the organic semiconductor layer using the composition for producing the organic semiconductor device, even if it is not after the production of the organic semiconductor layer. It can be added at the stage of forming a thin film or forming a thin film. In addition, the material used for doping is added to the material that forms the organic semiconductor layer during vapor deposition and co-deposited, or mixed with the surrounding atmosphere when the organic semiconductor layer is formed (in an environment where the doping material is present). It is also possible to make an organic semiconductor layer), and further, it is possible to accelerate ions in a vacuum and cause them to collide with a film for doping.
The effects of these dopings include changes in electrical conductivity due to an increase or decrease in carrier density, changes in carrier polarity (p-type, n-type), changes in Fermi levels, and the like.

(Formation of source electrode and drain electrode)
The source electrode 1 and the drain electrode 3 can be formed in the same manner as in the case of the gate electrode 5 (see FIG. 2 (5)). Further, various additives and the like can be used to reduce the contact resistance with the organic semiconductor layer.

(About the protective layer)
Forming the protective layer 7 on the organic semiconductor layer has an advantage that the influence of the outside air can be minimized and the electrical characteristics of the organic transistor can be stabilized (see FIG. 2 (6)). The above-mentioned material is used as the material of the protective layer. The film thickness of the protective layer 7 can be any film thickness depending on the purpose, but is usually 100 nm to 1 mm.
Various methods can be adopted for forming the protective layer, but when the protective layer is made of resin, for example, a method in which a resin solution is applied and then dried to form a resin film; a resin monomer is applied or vapor-deposited. A method of later polymerizing; and the like. Crosslinking may be performed after the film formation. When the protective layer is made of an inorganic substance, for example, a forming method by a vacuum process such as a sputtering method or a vapor deposition method, or a forming method by a solution process such as a sol-gel method can also be used.
In the organic transistor, a protective layer can be provided between the organic semiconductor layers as well as between the layers as needed. These layers may help stabilize the electrical properties of the organic transistor.

Since the condensed polycyclic aromatic compound represented by the above formula (1) or (2) is used as the organic semiconductor material, it can sufficiently withstand the process temperature in the production of other constituent members produced on the plastic substrate. can. As a result, it becomes possible to manufacture a lightweight, flexible and hard-to-break device, which can be used as a switching device for an active matrix of a display.

Organic transistors can also be used as digital devices and analog devices such as memory circuit devices, signal driver circuit devices, and signal processing circuit devices. Further, by combining these, it becomes possible to manufacture a display, an IC card, an IC tag, and the like. Further, since the organic transistor can change its characteristics by an external stimulus such as a chemical substance, it can also be used as a sensor.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.
In the following operations, an anhydrous distilled solvent was used for the reaction and measurement under the inert gas, and a commercially available first-class or special-grade solvent was used for other reactions and operations. The reagents were purified by anhydrous distillation or the like as needed, and commercially available first-class or special-grade reagents were used for the others. The analytical instruments and measuring instruments used are shown below. Nuclear magnetic resonance spectroscopy was performed using LAMBDA-NMR (395.75 MHz, σ value, ppm, internal standard TMS).

Example 1 (Synthesis of condensed polycyclic aromatic compound represented by No. 1 of the above specific example)
Compound No. The organic compound of the present invention represented by 1 was synthesized according to the following synthesis flow.

Precursor 3.3 g (4.75 mmol), bis (triphenylphosphine) palladium (II) dichloride 333 mg (0.475 mmol), sodium acetate 780 mg (9.50 mmol) described in the above flow in a 100 mL three-necked flask under a nitrogen atmosphere. ) And 40 mL of N, N-dimethylacetamide were added and heated at 120 ° C. for 10 hours. The reaction mixture was left to stand overnight in a refrigerator, the precipitated solid was filtered off, and then the crude product was extracted from the solid using a Soxhlet extractor (extraction solvent; chloroform). Chloroform was concentrated and the resulting solid was recrystallized from chloroform-hexane. By sublimating and purifying the organic compound obtained by recrystallization, the above No. 512 mg (yield 19%) of the condensed polycyclic aromatic compound of the present invention represented by 1 was obtained as a yellow solid.

No. obtained in Example 1. The measurement results of nuclear magnetic resonance spectroscopy of the condensed polycyclic aromatic compound represented by 1 are as follows.
^{1 1} H-NMR (400 MHz, CDCl ₃ ) σ1.31-1.36 (m, 12H), 1.61 (m, 1H), 1.71 (m, 1H), 2.79 (t, 2H), 3.36 (s, 3H), 3.51 (t, 2H), 4.62 (s, 2H), 7.28 (dd, 1H), 7.41 (m, 1H), 7.70-7 .54 (m, 2H), 7.70 (d, 1H), 7.76-7.81 (m, 3H), 7.85 (d, 1H), 8.01 (d, 1H), 8. 22 (d, 1H), 8.40 (s, 1H), 8,41 (s, 1H)

Example 2 (evaluation of solubility)
No. obtained in Example 1. About 1 mg of the powder of the condensed polycyclic aromatic compound represented by 1 was weighed into a vial, and the mass was accurately measured. Cyclohexanone and xylene were added thereto, and the mass of the solution was accurately measured when the condensed polycyclic aromatic compound was completely dissolved. No. The solubility (mass of condensed polycyclic aromatic compound / mass of each solution × 100) was calculated from the mass of the condensed polycyclic aromatic compound represented by 1 and the mass of the cyclohexanone solution or the xylene solution. The time when it was completely dissolved was determined by visual confirmation. The results are shown in Table 1.

Example 3 (Characteristic evaluation of organic transistor)
No. obtained in Example 1. An organic transistor device was prepared using the condensed polycyclic aromatic compound represented by 1, and the transistor characteristics were evaluated.
No. obtained in Example 2. An organic thin film was prepared by a spin coating method on an n-doped silicon wafer _{with a SiO 2} thermal oxide film surface-treated with phenetiltrichlorosilane using a xylene solution of the compound represented by 1. Next, a top contact type organic transistor was obtained by vacuum-depositing Au on the organic thin film obtained above using a shadow mask to prepare a source electrode and a drain electrode. The channel length of the obtained organic transistor was 20 μm, and the channel width was 100 μm.
FIG. 1B shows the structure of a top contact type organic transistor. In the organic transistor of this embodiment, the thermal oxide film on the n-doped silicon wafer has the function of the insulating layer 4, and the n-doped silicon wafer has the functions of the substrate 6 and the gate electrode 5.

The performance of the organic transistor obtained in Example 3 depends on the amount of current flowing when a potential is applied between the source electrode and the drain electrode while the potential is applied to the gate electrode. The mobility can be calculated by using the measurement result of this current value in the following formula (a) expressing the electrical characteristics of the carrier species generated in the organic semiconductor layer.
Id = ZμCi (Vg-Vt) ² / 2L ... (a)
In formula (a), Id is the saturated source / drain current value, Z is the channel width, Ci is the capacitance of the insulator, Vg is the gate potential, Vt is the threshold potential, L is the channel length, and μ is determined. Mobility mobility (cm ² / Vs). Ci is determined by _{the dielectric constant of the SiO 2} insulating film used, Z and L are determined by the device structure of the organic transistor device, Id and Vg are determined when measuring the current value of the organic transistor device, and Vt is determined by Id and Vg. can. By substituting each value into the equation (a), the mobility at each gate potential can be calculated.

For the transistor element created as described above, the change in drain current when the gate voltage was swept from + 20V to -80V under the condition of drain voltage -30V was measured, and the hole mobility and on-current calculated from the results were obtained. The off-current ratios are summarized in Table 2.

Since the condensed polycyclic aromatic compound represented by the formula (1) or (2) of the present invention has excellent solubility in a solvent, it can be easily obtained from an organic semiconductor composition containing the condensed polycyclic aromatic compound and an organic solvent. the organic thin film moldable, yet the organic transistor having an organic thin film, and exhibits excellent transistor characteristics hole mobility 1.0 cm 2 / ^Vs, the on / off ratio of 10 ^5.

Example 4 (Synthesis of condensed polycyclic aromatic compound represented by No. 41 of the above specific example)
By performing the same treatment as in Example 1 except that the precursor was changed to the compound represented by the following formula (5), the above No. 396 mg (yield 32%) of the condensed polycyclic aromatic compound of the present invention represented by 41 was obtained as a yellow solid.

No. obtained in Example 4. The measurement results of nuclear magnetic resonance spectroscopy of the condensed polycyclic aromatic compound represented by 41 were as follows.
^{1 1} H-NMR (400 MHz, CDCl ₃ ) σ1.25-1.40 (m, 12H), 1.77 (m, 4H), 2.79 (t, 2H), 3.94 (t, 2H), 6.90 (m, 3H), 7.25-7.29 (m, 3H), 7.41 (dd, 1H), 7.52 (dd, 2H), 7.70 (s, 1H), 7 .77 (d, 2H), 7.81 (s, 1H), 7.85 (d, 1H), 8.01 (d, 1H), 8.22 (d, 1H), 8.40 (s, 1H), 8,41 (s, 1H)

Example 5 (Synthesis of condensed polycyclic aromatic compound represented by No. 42 of the above specific example)
By performing the same treatment as in Example 1 except that the precursor was changed to the compound represented by the following formula (6), the above No. 198 mg (yield 29%) of the condensed polycyclic aromatic compound of the present invention represented by 42 was obtained as a yellow solid.

No. obtained in Example 5. The measurement results of nuclear magnetic resonance spectroscopy of the condensed polycyclic aromatic compound represented by 42 were as follows.
^{1 1} H-NMR (400 MHz, CDCl ₃ ) σ1.25-1.35 (m, 14H), 1.77 (m, 2H), 2.78 (t, 2H), 3.94 (t, 2H), 6.90 (m, 3H), 7.26 (m, 2H), 7.31 (d, 1H), 7.52 (m, 2H), 7.75 (s, 1H), 7.79 (d) , 1H), 7.93 (dd, 1H), 8.01 (dd, 1H), 8.33 (s, 1H), 8.38 (s, 1H)

Example 6 (evaluation of solubility)
No. The condensed polycyclic aromatic compound represented by 1 is No. The solubility was measured by the same method as in Example 2 except that the compound was changed to the condensed polycyclic aromatic compound represented by 41. The results are shown in Table 3.

Example 7 (evaluation of solubility)
No. The condensed polycyclic aromatic compound represented by 1 is No. The solubility was measured by the same method as in Example 2 except that the compound was changed to the condensed polycyclic aromatic compound represented by 42. The results are shown in Table 3.

Comparative Example 1 (Evaluation of solubility)
No. Example 2 except that the condensed polycyclic aromatic compound represented by 1 was changed to a comparative condensed polycyclic aromatic compound represented by the following formula (7) (a compound similar to the compound described in Patent Document 4). The solubility was measured in the same manner as in. The results are shown in Table 3.

From the results of Tables 1 and 3, although the condensed polycyclic aromatic compounds of Examples and Comparative Examples both have a BTNT skeleton, the condensed polycyclic aromatic compounds of Examples are condensed for comparison. It showed a solubility in organic solvents that was more than 5 times higher than that of polycyclic aromatic compounds.

Example 8 (Characteristic evaluation of organic transistor)
No. The xylene solution of the compound represented by 1 was obtained in Example 6 and No. An organic transistor device was produced in the same manner as in Example 3 except that the compound represented by 41 was changed to a xylene solution, and the transistor characteristics were evaluated. The results are shown in Table 4.

Example 9 (Characteristic evaluation of organic transistor)
No. The xylene solution of the compound represented by No. 1 was obtained in Example 7. An organic transistor device was produced in the same manner as in Example 3 except that the compound represented by 42 was changed to a xylene solution, and the transistor characteristics were evaluated. The results are shown in Table 4.

Comparative Example 2 (Characteristic evaluation of organic transistor)
No. An organic transistor device was produced in the same manner as in Example 3 except that the xylene solution of the compound represented by 1 was changed to the xylene solution of the compound represented by the formula (7) obtained in Comparative Example 1. The transistor characteristics were evaluated. The results are shown in Table 4.

In Comparative Example 2 using the compound represented by the formula (7), a thin film could not be formed by coating film formation because the solvent solubility of the compound was insufficient. On the other hand, since the condensed polyaromatic compound of the present invention used in Examples 8 and 9 has high solvent solubility, an organic transistor device could be easily produced. Further, Patent Documents 4 and 5 report that the hole mobility of the organic transistor using the compounds of these documents was 10-1 units, while the condensed polycyclic aromatic compound of the present invention. The hole mobility of the organic transistor using the above showed a value exceeding 1 at the maximum. From the above results, it is clear that the condensed polycyclic aromatic compound of the present invention has high solubility, and the organic transistor device obtained by using the compound exhibits excellent transistor characteristics.

Since the condensed polycyclic aromatic compound of the present invention has good solvent solubility, it is suitably used when producing an organic semiconductor device in a printing process, and an organic semiconductor device having an organic thin film obtained by using the compound. Expresses good semiconductor properties. Therefore, the present invention can be used in the fields of organic transistor devices, diodes, capacitors, thin film photoelectric conversion devices, dye-sensitized solar cells, organic EL devices, and the like.

Claims (15)

The following formula (1) or (2)

(In formulas (1) and (2), _one of R 1 and R ₂ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and the other represents a hydrogen atom. _{One of R 3} and R ₄ is represented by the following formula (3) or (4).

(In formulas (3) and (4), p, q and r each represent an integer of 1 to 20. X represents an oxygen atom or a sulfur atom independently. In formula (3), R ₅ is an aromatic. Represents a hydrocarbon group, in formula (4), R ₅ represents an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group), and the other represents a hydrogen atom. Represents. ) Is a condensed polycyclic aromatic compound. R ₁ and R ₄ are hydrogen atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and R ₃ is a formula (3) or (4). The condensed polycyclic aromatic compound according to claim 1, which is a substituent represented by. R ₁ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, R ₂ and R ₃ are hydrogen atoms, and R ₄ is a formula (3) or (4). The condensed polycyclic aromatic compound according to claim 1, which is a substituent represented by. The condensed polycyclic aromatic compound according to any one of claims 1 to 3, wherein any one of R ₃ and R _{4 is a substituent represented by the formula (3).} The condensed polycyclic aromatic compound according to claim 4, wherein p is an integer of 6 to 14. The condensed polycyclic aromatic compound according to any one of claims 1 to 3, wherein any one of R ₃ and R _{4 is a substituent represented by the formula (4).} The condensed polycyclic aromatic compound according to claim 6, wherein q is an integer of 6 to 14 and r is an integer of 1 to 4. The condensed polycyclic aromatic compound according to any one of claims 1 to 7, wherein R _{5 is an alkyl group having 1 to 4 carbon atoms.} The condensed polycyclic aromatic compound according to any one of claims 1 to 8, which does not exhibit liquid crystallinity. An organic semiconductor material containing the condensed polycyclic aromatic compound according to any one of claims 1 to 9. The organic semiconductor composition containing the organic semiconductor material and the organic solvent according to claim 10. An organic thin film containing the organic semiconductor material according to claim 10. The organic semiconductor device having the organic thin film according to claim 12. The organic semiconductor device according to claim 13, which is an organic transistor. A method for producing an organic thin film, which comprises a step of applying or printing the organic semiconductor composition according to claim 11 on a substrate, and a step of removing an organic solvent from the organic semiconductor composition coated or printed on the substrate.

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