Condensed polycyclic aromatic compound

Abstract

The purpose of the present invention is to provide: a fused polycyclic aromatic compound having excellent heat resistance in a practical process temperature range; an organic thin film containing said compound; and an organic semiconductor device (field-effect transistor, organic photoelectric conversion element) having said organic thin film. The present invention includes a fused polycyclic aromatic compound represented by general formula (1): (in formula (1), regarding R1 and R2, one represents a hydrogen atom and the other represents a substituent represented by general formula (2) or (3): (in formulas (2) and (3), n represents an integer of 0-2, X represents an oxygen atom, a sulfur atom, or a selenium atom, R3 represents a hydrogen atom or a substituted or unsubstituted aromatic hydrocarbon group)).

Description

Technical Field

[0001] The present invention relates to a novel condensed polycyclic aromatic compound and its use. More specifically, the present invention relates to a condensed polycyclic aromatic compound which is a benzothieno[3,2-b][1]benzothiophene (hereinafter abbreviated as "BTBT") derivative, an organic thin film containing the compound, and an organic semiconductor device (field effect transistor, organic optoelectronic conversion element) having the organic thin film.

Background Art

[0002] In recent years, organic thin film devices such as field effect transistors and organic optoelectronic conversion elements have attracted attention, and various organic electronics materials represented by condensed polycyclic aromatic compounds used in these thin film devices have been studied and developed. For example, Patent Document 1 shows that a BTBT derivative exhibits excellent charge mobility and its thin film has organic semiconductor properties.

[0003] Also, Patent Document 2 reports a field effect transistor fabricated by a solution process using an alkyl derivative of BTBT.

[0004] As described above, development of BTBT derivatives, which are beneficial as organic electronics compounds, has been carried out so far. However, the BTBT derivatives in these documents have a problem that the organic semiconductor properties are significantly deteriorated in the heat annealing process after fabricating the electrodes of the field effect transistor element.

[0005] On the other hand, organic optoelectronic conversion elements are expected to be developed for next-generation imaging devices, and reports have been made by several groups. For example, there are an example of using a quinacridone derivative in an optoelectronic conversion element (Patent Document 3), an example of applying an optoelectronic conversion element using a quinacridone derivative to an imaging device (Patent Document 4), and an example of using a diketopyrrolopyrrole derivative (Patent Document 5).

[0006] As described above, although the development of a photoelectric conversion element having sensitivity in the visible light region using an organic semiconductor has been carried out, the BTBT derivatives reported in these documents have a problem of low sensitivity in the visible light region.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Non-Patent Documents

[0008]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been made in view of the above conventional problems, and an object thereof is to provide a condensed polycyclic aromatic compound excellent in heat resistance in a practical process temperature range, an organic thin film containing the compound, and an organic semiconductor device (field effect transistor, organic photoelectric conversion element) having the organic thin film.

Means for Solving the Problems

[0010] As a result of intensive studies, the present inventors have found that the above problems can be solved by using a novel condensed polycyclic aromatic compound having a specific structure, and have completed the present invention. That is, the present invention relates to [1] A condensed polycyclic aromatic compound represented by the general formula (1)

[0011] [Chemical formula]

[0012] (In the formula (1), one of R1 and R2 is a substituent represented by the general formula (2) or (3)

[0013] [Chemical formula]

[0014] (In the formulas (2) and (3), n represents an integer of 0 to 2. X represents an oxygen atom, a sulfur atom or a selenium atom. R3 represents a hydrogen atom or a substituted or unsubstituted aromatic hydrocarbon group.) and the other represents a hydrogen atom.) A condensed polycyclic aromatic compound represented by [2] The condensed polycyclic aromatic compound according to [1], wherein R3 is a hydrogen atom; [3] The condensed polycyclic aromatic compound according to [1], wherein R3 is a phenyl group, a biphenyl group or a naphthyl group; [4] The condensed polycyclic aromatic compound according to [3], wherein R3 is a phenyl group; [5] The condensed polycyclic aromatic compound according to any one of [1] to [4], wherein one of R1 and R2 is a substituent represented by the general formula (2); [6] The condensed polycyclic aromatic compound according to any one of [1] to [4], wherein one of R1 and R2 is a substituent represented by the general formula (3); [7] The condensed polycyclic aromatic compound according to any one of [1] to [6], wherein n is 1; [8] The condensed polycyclic aromatic compound according to any one of [1] to [7], wherein X is an oxygen atom or a sulfur atom; A material for an organic optoelectronic conversion device comprising a condensed polycyclic aromatic compound according to any one of [1] to [8] in [9]; An organic thin film comprising a condensed polycyclic aromatic compound according to any one of [1] to [8] in

[10] ; A field effect transistor having the organic thin film described in

[11]

[10] ; and An organic optoelectronic conversion device having the organic thin film described in

[12]

[10] ; relates to.

Effects of the Invention

[0015] According to the present invention, a condensed polycyclic aromatic compound excellent in heat resistance in a practical process temperature range, an organic thin film containing the compound, and an organic semiconductor device (field effect transistor, organic optoelectronic conversion device) having the organic thin film can be provided.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0017] The present invention will be described in more detail below. The condensed polycyclic aromatic compound of the present invention is represented by the above general formula (1). In general formula (1), one of R1 and R2 represents a substituent represented by the above general formula (2) or (3), and the other represents a hydrogen atom. As R1 and R2 in formula (1), it is preferable that one of them is a substituent represented by the above general formula (2) and the other is a hydrogen atom, and it is more preferable that R1 is a substituent represented by the above general formula (2) and R2 is a hydrogen atom.

[0018] In general formulas (2) and (3), n represents an integer from 0 to 2, preferably 1 or 2, and more preferably 1. In addition, in the substituents represented by general formulas (2) and (3), when n = 0, it is a residue obtained by removing one hydrogen atom from thienothiophene, furan, or selenophenoselenophene; when n = 1, it is a residue obtained by removing one hydrogen atom from benzodithiophene, benzodifuran, or benzodiselenophene; when n = 2, it is a residue obtained by removing one hydrogen atom from naphthodithiophene, naphthodifuran, or naphthodiselenophene.

[0019] In general formulas (2) and (3), X represents an oxygen atom, a sulfur atom, or a selenium atom, preferably an oxygen atom or a sulfur atom, and more preferably a sulfur atom.

[0020] In General Formulas (2) and (3), R3 represents a hydrogen atom or a substituted or unsubstituted aromatic hydrocarbon group. The aromatic hydrocarbon group represented by R3 is a residue obtained by removing one hydrogen atom from the aromatic ring of an aromatic hydrocarbon compound, and the aromatic hydrocarbon group preferably has 5 to 20 carbon atoms. Specific examples include a phenyl group, a biphenyl group (1-biphenyl group, 2-biphenyl group), a naphthyl group (1-naphthyl group, 2-naphthyl group), and the like. Among them, a phenyl group is more preferable. Note that "substituted or unsubstituted" means "having a substituent or not having a substituent", and "substituted or unsubstituted aromatic hydrocarbon group" means an aromatic hydrocarbon group having a substituent or an aromatic hydrocarbon not having a substituent. The substituent is not particularly limited.

[0021] Next, the method for synthesizing the condensed polycyclic aromatic compound represented by General Formula (1) of the present invention will be described in detail. The condensed polycyclic aromatic compound represented by General Formula (1) can be synthesized by various conventionally known methods. As an example, the synthesis method of the following scheme will be described.

[0022] The compound represented by formula (1) can be synthesized by known methods disclosed in Patent Document 6, Patent Document 7, and Non-Patent Document 1, etc. For example, a synthesis method according to the following scheme can be mentioned. Using a nitrostilbene derivative (A') as a raw material, a benzothieno[3,2-b]benzothiophene skeleton (D) is formed, and by reducing this, an amino compound (E) is obtained. If this compound (E) is halogenated, a halide (F) (although an iodide is described as an example of the halide (F) in the following scheme, it is not limited thereto) is obtained, and by further coupling this halide (F) with a boronic acid derivative (G'), a compound represented by formula (1') (a compound in which R1 in formula (1) is a substituent of formula (2) or formula (3) and R2 is a hydrogen atom) can be obtained. According to the method of Patent Document 5, since the compound represented by formula (1') can be produced in one step from the corresponding benzaldehyde derivative, it is more efficient. Note that R1 of the boronic acid derivative (G') corresponds to R1 of formula (1').

[0023]

Chemical formula

[0024] In addition, by changing the starting material in the above scheme from the nitrostilbene derivative (A') to the nitrostilbene derivative (A'') represented by the following formula, and changing the boronic acid derivative (G') to the boronic acid derivative (G'') represented by the following formula, a compound represented by the following formula (1'') (a compound in which R1 in formula (1) is a hydrogen atom and R2 is a substituent) can be obtained.

[0025]

Chemical formula

[0026] In the above coupling reaction, it is preferable to use 2 to 10 moles, and more preferably 2 to 4 moles of the boronic acid derivative (G') or (G'') with respect to 1 mole of the halide (F). The reaction temperature of the above coupling reaction is usually -10 to 200 °C, preferably 40 to 160 °C, more preferably 60 to 120 °C. Also, the reaction time is not particularly limited, but is usually 1 to 72 hours, preferably 3 to 48 hours. Depending on the type of catalyst described later, the reaction temperature can be lowered or the reaction time can be shortened. The above coupling reaction is preferably carried out under an inert gas atmosphere such as an argon atmosphere, under nitrogen substitution, under a dry argon atmosphere, or under a dry nitrogen stream.

[0027] It is preferable to use a catalyst for the coupling reaction using the halide (F). Examples of catalysts that can be used in the coupling reaction include, for example, 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 (hydrous or anhydrous), palladium acetate, palladium trifluoroacetate, palladium methanesulfonate, palladium toluenesulfonate, palladium chloride, palladium bromide, palladium iodide, bis(acetonitrile)palladium(II) dichloride, bis(benzonitrile)palladium(II) dichloride, tetrakis(acetonitrile)palladium(II) tetrafluoroborate, tris(dibenzylideneacetone)dipalladium(0), tris(dibenzylideneacetone)dipalladium(0) chloroform complex and bis(dibenzylideneacetone)palladium(0), bis(triphenylphosphino)palladium dichloride (Pd(PPh3)2Cl2), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (Pd(dppf)Cl2), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), etc. are mentioned, but palladium-based catalysts are preferred. Pd(dppf)Cl2, Pd(PPh3)2Cl2, Pd(PPh3)4 are more preferred, and Pd(PPh3)4 is even more preferred. These catalysts may be used as a mixture of multiple types, or other catalysts may be mixed with these catalysts for use. The amount of these catalysts used in the coupling reaction is preferably 0.001 to 0.500 mol, more preferably 0.001 to 0.200 mol, still more preferably 0.001 to 0.100 mol, and most preferably 0.001 to 0.050 mol per 1 mol of the halide (F).

[0028] For the coupling reaction using the halide (F), it is preferable to use a basic compound. Examples of the basic compound include hydroxides such as lithium hydroxide, barium hydroxide, sodium hydroxide, and potassium hydroxide; carbonates such as lithium carbonate, lithium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, and cesium carbonate; acetates such as lithium acetate, sodium acetate, and potassium acetate; phosphates such as trisodium phosphate and tripotassium phosphate; alkoxides such as sodium methoxide, sodium ethoxide, and potassium tert-butoxide; metal hydrides such as sodium hydride and potassium hydride; and organic bases such as pyridine, picoline, lutidine, triethylamine, tributylamine, diisopropylethylamine, and N,N-dicyclohexylmethylamine. Phosphates or hydroxides are preferred, and trisodium phosphate, tripotassium phosphate, sodium hydroxide, or potassium hydroxide are more preferred. These basic compounds may be used alone or in combination of two or more. The amount of these basic compounds used in the coupling reaction is preferably 1 to 100 mol, more preferably 1 to 10 mol per 1 mol of the halide (F).

[0029] The above coupling reaction may be carried out in a solvent. Any solvent that can dissolve the necessary raw materials, such as the halide (F) or the borate derivative, and further, if necessary, the catalyst, basic compound, alkali metal salt, etc., can be used. Specific examples of the solvent include aromatic compounds such as chlorobenzene, o-dichlorobenzene, bromobenzene, nitrobenzene, toluene, and xylene; saturated aliphatic hydrocarbons such as n-hexane, n-heptane, and n-pentane; alicyclic hydrocarbons such as cyclohexane, cycloheptane, and cyclopentane; saturated aliphatic halogenated hydrocarbons such as n-propyl bromide, n-butyl chloride, n-butyl bromide, dichloromethane, dibromomethane, dichloropropane, dibromopropane, dichlorobutane, chloroform, bromoform, carbon tetrachloride, carbon tetrabromide, trichloroethane, tetrachloroethane, and pentachloroethane; halogenated cyclic hydrocarbons such as chlorocyclohexane, chlorocyclopentane, and bromocyclopentane; esters such as ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, and butyl butyrate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as diethyl ether, dipropyl ether, dibutyl ether, cyclopentyl methyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, and 1,3-dioxane; amides such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide; glycols such as ethylene glycol, propylene glycol, and polyethylene glycol; and sulfoxides such as dimethyl sulfoxide. These solvents may be used alone or in combination of two or more.

[0030] The purification method of the condensed polycyclic aromatic compound represented by the general formula (1) is not particularly limited, and known methods such as recrystallization, column chromatography, and vacuum sublimation purification can be employed. These methods can also be combined as necessary.

[0031] Specific examples of the condensed polycyclic aromatic compound of the present invention represented by the general formula (1) in which R3 in the formula (2) or (3) is a hydrogen atom are shown below, but the present invention is not limited to these specific examples.

[0032] [Chemical formula]

[0033] [Chemical formula]

[0034] [Chemical formula]

[0035] [Chemical formula]

[0036] [Chemical formula]

[0037] [Chemical formula]

[0038] Furthermore, as specific examples of the condensed polycyclic aromatic compound of the present invention represented by the general formula (1) in which R3 in the formulas (2) and (3) is an aromatic hydrocarbon group, compounds in which an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, and a naphthyl group is substituted on the furan ring or thiophene ring having the compounds represented by the above Nos. 1 to 36 at both ends can be mentioned. The substitution position is not particularly limited. For example, there is a case where a substituent is bonded to a carbon atom adjacent to the S atom, Se atom, or O atom at both ends of the condensed polycyclic aromatic compound of the present invention.

[0039] The organic thin film of the present invention contains a condensed polycyclic aromatic compound represented by the formula (1). The film thickness of the organic thin film varies depending on its use, but is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

[0040] Examples of the method for forming an organic thin film include dry processes such as vapor deposition and various solution processes, and it is preferable to form the film by a solution process. Examples of the solution process include spin coating, drop casting, dip coating, spraying, relief printing methods such as flexographic printing and resin letterpress printing, planographic printing methods such as offset printing, dry offset printing, and pad printing, intaglio printing methods such as gravure printing, screen printing, stencil printing, and ring graph printing, inkjet printing, microcontact printing, etc., and further, methods combining a plurality of these techniques. When forming a film by a solution process, after the above coating and printing, it is preferable to evaporate the solvent to form a thin film.

[0041] The field effect transistor of the present invention controls the current flowing between two electrodes (source electrode and drain electrode) provided in contact with the organic thin film of the present invention by a voltage applied to another electrode called a gate electrode.

[0042] In a field effect transistor, a structure in which a gate electrode is insulated by an insulating film (Metal-Insulator-Semiconductor MIS structure) is generally used. When a metal oxide film is used for the insulating film, it is called a MOS structure. In addition, a structure in which a gate electrode is formed via a Schottky barrier (i.e., MES structure) is also known, but in the case of a field effect transistor, the MIS structure is often used.

[0043] In each exemplary embodiment of the field-effect transistor shown in FIG. 1, 1 represents the source electrode, 2 represents the organic thin film (semiconductor layer), 3 represents the drain electrode, 4 represents the insulator layer, 5 represents the gate electrode, and 6 represents the substrate. Note that the arrangement of each layer and electrode can be appropriately selected according to the use of the device. Since current flows in the direction parallel to the substrate in A to D and F, they are called lateral transistors. A is called a bottom-contact bottom-gate structure, and B is called a top-contact bottom-gate structure. Further, in C, a source electrode, a drain electrode, and an insulator layer are provided on the semiconductor, and a gate electrode is further formed thereon, which is called a top-contact top-gate structure. D is a structure called a top & bottom-contact bottom-gate transistor. F is 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 flow of current spreads in a planar shape, a large number of carriers can move at once. Further, since the source electrode and the drain electrode are arranged vertically, the distance between the electrodes can be reduced, so the response is fast. Therefore, it can be preferably applied to applications such as flowing a large current and performing high-speed switching. Although the substrate is not shown in E in FIG. 1, in a normal case, a substrate is provided outside the source electrode or the drain electrode represented by 1 and 3 in FIG. 1E.

[0044] Each component in each exemplary embodiment will be described. The substrate 6 needs to be able to hold each layer formed thereon without peeling. For example, insulating materials such as resin plates, films, papers, glasses, quartz, and ceramics; materials obtained by forming an insulating layer by coating or the like on a conductive substrate such as a metal or an alloy; materials composed of various combinations such as resins and inorganic materials can be used. Examples of resin films that can be used include polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyamide, polyimide, polycarbonate, cellulose triacetate, polyetherimide, and the like. When a resin film or paper is used, the device can be made flexible, flexible, lightweight, and the practicality is improved. The thickness of the substrate is usually 1 μm to 10 mm, preferably 5 μm to 5 mm.

[0045] Conductive materials are used for the source electrode 1, drain electrode 3, and 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, sodium, and alloys containing them; conductive oxides such as InO2, ZnO2, SnO2, ITO; conductive polymer compounds such as polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylenevinylene, polydiacetylene; semiconductors such as silicon, germanium, gallium arsenide; carbon materials such as carbon black, fullerene, carbon nanotube, graphite, graphene, etc. can be used. Further, the conductive polymer compound and 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 PF5, AsF5, FeCl3; halogen atoms such as iodine; metal atoms such as lithium, sodium, potassium, etc. Boron, phosphorus, arsenic, etc. are also frequently used as dopants for inorganic semiconductors such as silicon.

[0046] In addition, a conductive composite material in which carbon black, metal particles, etc. are dispersed in the above dopant is also used. It is important to select an appropriate work function or perform surface treatment, etc. for the source electrode 1 and drain electrode 3 that directly contact the semiconductor in order to reduce the contact resistance.

[0047] Also, the distance between the source electrode and the drain electrode (channel length) is an important factor determining 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 extracted increases, but short-channel effects such as the influence of contact resistance may occur, which may deteriorate the semiconductor characteristics. The channel length is usually from 0.01 to 300 μm, preferably from 0.1 to 100 μm. The width between the source electrode and the drain electrode (channel width) is usually from 10 to 5000 μm, preferably from 40 to 2000 μm. Also, this channel width can be made even longer by making the structure of the electrode a comb-shaped structure or the like, and it is necessary to set it to an appropriate length depending on the required amount of current and the structure of the device.

[0048] The structure (shape) of each 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 from each other.

[0049] In the case of a bottom contact structure, generally, each electrode is fabricated using a lithography method, and each electrode is preferably formed in a rectangular parallelepiped shape. Recently, the printing accuracy of various printing methods has been improving, and it has become possible to accurately fabricate electrodes using techniques such as inkjet printing, gravure printing, or screen printing. In the case of a top contact structure having an electrode on a semiconductor, evaporation can be performed using a shadow mask or the like. It has also 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 above-described channel width. There is no particular regulation on the width of the electrode, but in order to reduce the area of the device within a range where the electrical characteristics can be stabilized, a shorter width is preferable. The width of the electrode is usually from 0.1 to 1000 μm, preferably from 0.5 to 100 μm. The thickness of the electrode is usually from 0.1 to 1000 nm, preferably from 1 to 500 nm, and more preferably from 5 to 200 nm. Wires are connected to each of the electrodes 1, 3, and 5, and the wires are also fabricated from a material substantially the same as that of the electrodes.

[0050] As the insulator layer 4, a material having insulating properties is used. For example, polymers such as poly(p-xylylene), polyacrylate, polymethyl methacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, polysiloxane, polyolefin, fluororesin, epoxy resin, and phenol resin, and copolymers obtained by combining these; metal oxides such as silicon oxide, aluminum oxide, titanium oxide, and tantalum oxide; ferroelectric metal oxides such as SrTiO3 and BaTiO3; dielectrics such as silicon nitride, aluminum nitride, sulfides, and fluorides; or polymers in which particles of these dielectrics are dispersed can be used. This insulator layer can preferably be one having high electrical insulation properties in order to reduce the leakage current. Thereby, the film thickness can be made thin, the insulation capacitance can be increased, and the current that can be extracted 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 irregularities. For this purpose, 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 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, and more preferably 1 nm to 10 μm.

[0051] As the material of the semiconductor layer 2, the condensed polycyclic aromatic compound of the present invention is used. An organic semiconductor film can be formed by a method according to the method for forming an organic thin film shown above, and used as the semiconductor layer 2.

[0052] Regarding the semiconductor layer 2 (organic thin film), a plurality of layers may be formed, but a single-layer structure is more preferable. The film thickness of the semiconductor layer 2 is preferably as thin as possible within a range that does not lose the necessary functions. In the horizontal field effect transistors shown in A, B, and D, if the film thickness is above a certain level, the characteristics of the device do not depend on the film thickness, but as the film thickness increases, the increase in leakage current becomes larger. The film thickness of the semiconductor layer 2 for exhibiting the necessary functions is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

[0053] In a field-effect transistor, 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, and on the outer surface of the device. For example, forming a protective layer directly on the semiconductor layer 2 or via another layer can reduce the influence of external air such as humidity. There are also advantages in stabilizing electrical characteristics, such as being able to increase the on / off ratio of the field-effect transistor.

[0054] The material of the protective layer is not particularly limited. For example, films made of various resins such as epoxy resin, acrylic resins such as polymethyl methacrylate, polyurethane, polyimide, polyvinyl alcohol, fluororesin, and polyolefin; inorganic oxide films such as silicon oxide, aluminum oxide, and silicon nitride; and films made of dielectrics such as nitride films are preferably used. In particular, resins (polymers) with low oxygen and moisture permeation rates and water absorption rates are preferred. Gas barrier protective materials developed for organic EL displays can also be used. The film thickness of the protective layer can be selected arbitrarily according to the purpose, but is usually 100 nm to 1 mm.

[0055] Moreover, by performing surface modification or surface treatment on the substrate or insulator layer on which the organic thin film is laminated in advance, it is possible to improve the characteristics as a field-effect transistor. For example, by adjusting the degree of hydrophilicity / hydrophobicity of the substrate surface, the film quality and film-forming properties 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. Therefore, by surface treatment of the substrate, insulator layer, etc., the molecular orientation at the interface with the organic thin film to be formed later is controlled, or the trap sites on the substrate or insulator layer are reduced, thereby improving characteristics such as carrier mobility.

[0056] The trap site refers to a functional group such as a hydroxyl group present on the untreated substrate. When such a functional group exists, electrons are attracted to the functional group, resulting in a decrease in carrier mobility. Therefore, reducing trap sites is often effective in improving characteristics such as carrier mobility.

[0057] As surface treatments for improving the characteristics as described above, for example, self-assembled monolayer treatments with hexamethyldisilazane, octyltrichlorosilane, octadecyltrichlorosilane, etc., surface treatments with polymers, etc., acid treatments with hydrochloric acid, sulfuric acid, acetic acid, etc., alkali treatments with sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc., ozone treatments, fluorination treatments, plasma treatments with oxygen, argon, etc., formation treatments of Langmuir-Blodgett films, formation treatments of thin films of other insulators and semiconductors, mechanical treatments, electrical treatments such as corona discharge, rubbing treatments using fibers, etc. can be mentioned, and combined treatments thereof can also be performed.

[0058] In these aspects, for example, as methods for providing each layer such as a substrate layer and an insulating film layer or an insulating film layer and a semiconductor layer (organic thin film), etc., the above-described vacuum process and solution process can be appropriately adopted.

[0059] Next, regarding the manufacturing method of the field-effect transistor of the present invention, taking the top-contact bottom-gate type field-effect transistor shown in Embodiment Example B of FIG. 1 as an example, it will be described below with reference to FIG. 2. This manufacturing method can be similarly applied to field-effect transistors and the like of other aspects described above.

[0060] (Regarding the substrate and substrate treatment of the field-effect transistor) The field-effect transistor of the present invention is manufactured by providing various necessary layers and electrodes on a substrate 6 (see FIG. 2(1)). As the substrate, those described above can be used. It is also possible to perform the above-described surface treatment, etc. on this substrate. The thickness of the substrate 6 is preferably thin within a range that does not interfere with the necessary functions. Although it varies depending on the material, it is usually 1 μm to 10 mm, and preferably 5 μm to 5 mm. Also, if necessary, the substrate can be made to have the function of an electrode.

[0061] (Regarding the formation of the gate electrode) A gate electrode 5 is formed on a substrate 6 (see Fig. 2(2)). As the electrode material, those described above are used. As a method for forming the electrode film, various methods can be used. For example, a vacuum evaporation method, a sputtering method, a coating method, a thermal transfer method, a printing method, a sol-gel method, etc. are adopted. It is preferable to perform patterning as necessary so as to obtain a desired shape during or after film formation. As a patterning method, various methods can be used. For example, a photolithography method that combines patterning of a photoresist and etching can be mentioned. Also, an evaporation method or a sputtering method using a shadow mask, a printing method such as inkjet printing, screen printing, offset printing, letterpress printing, a soft lithography technique such as a microcontact printing method, and a method combining a plurality of these techniques can be used for patterning. 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. Also, when it also serves as a gate electrode and a substrate, it may be larger than the above film thickness.

[0062] (Regarding the formation of the insulator layer) Form an insulator layer 4 on the gate electrode 5 (see Fig. 2(3)). As the material of the insulator layer 4, the materials described above are used. Various methods can be used to form the insulator layer 4. For example, coating methods such as spin coating, spray coating, dip coating, casting, bar coating, blade coating, etc., printing methods such as screen printing, offset printing, inkjet, etc., dry process methods such as vacuum evaporation, molecular beam epitaxial growth, ion cluster beam method, ion plating method, sputtering method, atmospheric pressure plasma method, CVD method, etc. can be mentioned. In addition, methods such as the sol-gel method and methods of forming an oxide film by thermal oxidation on a metal such as anodized aluminum on aluminum and silicon oxide on silicon are adopted. In addition, at the portion where the insulator layer and the semiconductor layer are in contact, in order to favorably orient the molecules of the compound constituting the semiconductor at the interface between the two layers, a predetermined surface treatment can be performed on the insulator layer. As the surface treatment method, the same methods as those for 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 extracted can be increased by increasing its capacitance. At this time, when the film becomes thin, the leakage current increases, so it is preferably thin within a range that does not impair its function. It is usually from 0.1 nm to 100 μm, preferably from 0.5 nm to 50 μm, and more preferably from 5 nm to 10 μm.

[0063] (Regarding the formation of the organic thin film) When forming the organic thin film (semiconductor layer), various methods such as methods by coating and printing can be used. Specifically, coating methods such as dip coating method, die coater method, roll coater method, bar coater method, spin coating method, etc., and formation methods by solution processes such as inkjet method, screen printing method, offset printing method, microcontact printing method, etc. can be mentioned.

[0064] A method for forming an organic thin film by a solution process will be described. An organic semiconductor composition is applied to a substrate (exposed portions of an insulator layer, a source electrode, and a drain electrode). Examples of the coating method include spin coating, drop casting, dip coating, spraying, relief printing methods such as flexographic printing and letterpress printing, planographic printing methods such as offset printing, dry offset printing, and pad printing, intaglio printing methods such as gravure printing, screen printing, mimeograph printing, stencil printing methods such as ring graph printing, inkjet printing, microcontact printing, and further, methods combining a plurality of these techniques.

[0065] Furthermore, as a method similar to the coating method, the Langmuir projection method of transferring and laminating a monomolecular film of an organic thin film prepared by dropping the above composition onto the water surface onto a substrate, a method of sandwiching a liquid crystal or a molten material between two substrates and introducing it between the substrates by capillary action, etc. can also be adopted.

[0066] The environment such as the temperature of the substrate and the composition during film formation is also important. Since the characteristics of the field effect transistor may change depending on the temperature of the substrate and the composition, 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. Attention is required because it greatly depends on the solvent in the composition used.

[0067] The film thickness of the organic thin film produced by this method is preferably thinner within a range that does not impair the function. There is a concern that the leakage current increases as the film thickness increases. The film thickness of the organic thin film is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, and more preferably 10 nm to 300 nm.

[0068] The thus-formed organic thin film (see Fig. 2(4)) can have its properties further improved by post-treatment. For example, by heat treatment, the strain in the film generated during film formation can be relaxed, pinholes and the like can be reduced, and the arrangement and orientation in the film can be controlled. For these reasons, the improvement and stabilization of organic semiconductor properties can be achieved. Performing this heat treatment during the fabrication of the field-effect transistor of the present invention is effective for improving the properties. The heat treatment is performed by heating the substrate after forming the organic thin film. The temperature of the heat treatment is not particularly limited, but is usually from room temperature to about 180°C, preferably 40 to 160°C, more preferably 45 to 150°C. The heat treatment time at this time is not particularly limited, but is usually from 10 seconds to 24 hours, preferably about 30 seconds to 3 hours. The atmosphere at that time may be in air, but may also be an inert atmosphere such as nitrogen or argon. In addition, control of the film shape by solvent vapor is possible.

[0069] As another post-treatment method for the organic thin film, treatment with an oxidizing or reducing gas such as oxygen or hydrogen, or an oxidizing or reducing liquid can also induce property changes due to oxidation or reduction. This can be utilized, for example, for the purpose of increasing or decreasing the carrier density in the film.

[0070] Also, in a technique called doping, the characteristics of an organic thin film can be changed by adding trace amounts of elements, atomic groups, molecules, or polymers to the organic thin film. For example, acids such as oxygen, hydrogen, hydrochloric acid, sulfuric acid, and sulfonic acid; Lewis acids such as PF5, AsF5, and FeCl3; halogen atoms such as iodine; metal atoms such as sodium and potassium; and donor compounds such as tetrathiafulvalene (TTF) and phthalocyanine can be doped. This can be achieved by bringing these gases into contact with the organic thin film, immersing it in a solution, or performing an electrochemical doping treatment. These dopings can be added not only after the production of the organic thin film, but also during the synthesis of the organic semiconductor compound, to the organic semiconductor composition, or in the process of forming the organic thin film. Also, a material used for doping can be added to the material for forming the organic thin film during evaporation for co-evaporation, or mixed into the surrounding atmosphere when producing the organic thin film (producing the organic thin film in an environment where the doping material is present). Furthermore, it is also possible to accelerate ions in a vacuum and make them collide with the film for doping.

[0071] The effects of these dopings include changes in electrical conductivity due to an increase or decrease in carrier density, changes in the polarity of carriers (p-type, n-type), changes in the Fermi level, etc.

[0072] (Formation of Source and Drain Electrodes) The formation method of the source electrode 1 and the drain electrode 3 can be formed according to the case of the gate electrode 5 (see Fig. 2(5)). Also, various additives can be used to reduce the contact resistance with the organic thin film.

[0073] (Regarding the Protection Layer) When the protection layer 7 is formed on the organic thin film, there are advantages that the influence of the outside air can be minimized and the electrical characteristics of the field effect transistor can be stabilized (see Fig. 2(6)). The materials described above are used as the material of the protection layer. The film thickness of the protection layer 7 can adopt an arbitrary film thickness according to the purpose, but it is usually 100 nm to 1 mm.

[0074] When forming the protective layer, various methods can be adopted. When the protective layer is made of resin, for example, there are methods such as applying a resin solution and then drying it to form a resin film; methods of polymerizing after applying or vapor-depositing a resin monomer, etc. Cross-linking treatment may be performed after film formation. When the protective layer is made of an inorganic substance, for example, formation methods in vacuum processes such as sputtering method and vapor deposition method, and formation methods in solution processes such as sol-gel method can also be used.

[0075] In a field-effect transistor, in addition to on the organic thin film, a protective layer can also be provided between each layer as needed. These layers may help to stabilize the electrical characteristics of the field-effect transistor.

[0076] The field-effect transistor can also be used as digital devices such as memory circuit devices, signal driver circuit devices, and signal processing circuit devices, as well as analog devices. Furthermore, by combining these, it becomes possible to fabricate displays, IC cards, IC tags, etc. Moreover, since the characteristics of the field-effect transistor can be changed by external stimuli such as chemical substances, it can also be used as a sensor.

[0077] The material for an organic optoelectronic conversion element of the present invention contains a condensed polycyclic aromatic compound represented by the above formula (1). The content of the compound represented by the formula (1) in the material for an organic optoelectronic conversion element of the present invention is not particularly limited as long as the performance required in the application using the material for an organic optoelectronic conversion element is exhibited, but it is usually 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. In the material for an organic optoelectronic conversion element of the present invention, compounds other than the compound represented by the formula (1) (for example, materials for organic optoelectronic conversion elements other than the compound represented by the formula (1)) and additives, etc. may be used in combination. The compounds and additives, etc. that can be used in combination are not particularly limited as long as the performance required in the application using the material for an organic optoelectronic conversion element is exhibited.

[0078] The organic optoelectronic conversion device of the present invention has the organic thin film of the present invention. The organic optoelectronic conversion device is a device in which a photoelectric conversion part (film) is arranged between a pair of opposing electrode films, and light is incident on the photoelectric conversion part from above the electrode films. The photoelectric conversion part generates electrons and holes in response to the incident light, and a signal corresponding to the charge is read out by a semiconductor, and it is a device that shows the amount of incident light corresponding to the absorption wavelength of the photoelectric conversion film part. A transistor for reading may be connected to the electrode film on the side where no light is incident. When a large number of organic optoelectronic conversion devices are arranged in an array, in addition to the amount of incident light, the incident position information is also shown, so it becomes an imaging device. Also, when the organic optoelectronic conversion device arranged closer to the light source does not shield (transmits) the absorption wavelength of the organic optoelectronic conversion device arranged behind it when viewed from the light source side, a plurality of organic optoelectronic conversion devices may be stacked and used.

[0079] The organic optoelectronic conversion device of the present invention uses an organic thin film containing the condensed polycyclic aromatic compound represented by the above formula (1) as a constituent material of the photoelectric conversion part. The photoelectric conversion part often consists of a photoelectric conversion layer and one or more organic thin film layers other than the photoelectric conversion layer selected from the group consisting of an electron transport layer, a hole transport layer, an electron blocking layer, a hole blocking layer, a crystallization prevention layer, and an interlayer contact improvement layer, etc. The condensed polycyclic aromatic compound of the present invention is preferably used as the organic thin film layer of the photoelectric conversion layer, but it can also be used as the above-mentioned organic thin film layer (particularly, the electron transport layer, the hole transport layer, the electron blocking layer, the hole blocking layer). The electron blocking layer and the hole blocking layer are also referred to as carrier blocking layers. Also, when used for the photoelectric conversion layer, it may be composed only of the condensed polycyclic aromatic compound of the present invention, but it may contain an organic semiconductor material in addition to the condensed polycyclic aromatic compound of the present invention. These organic thin film layers may have a laminated structure, but may contain an organic thin film formed by co-evaporation of materials, and in addition, a co-evaporation film, a single film, or another co-evaporation film may be formed in multiple layers to form an organic thin film that functions.

[0080] The electrode film used in the organic optoelectronic conversion element of the present invention serves to extract holes from the photoelectric conversion layer or other organic thin film layers and collect them when the photoelectric conversion layer included in the photoelectric conversion section described later has hole transporting properties or when the other organic thin film layer is a hole transporting layer having hole transporting properties. Also, when the photoelectric conversion layer included in the photoelectric conversion section has electron transporting properties or when the organic thin film layer is an electron transporting layer having electron transporting properties, it serves to extract electrons from the photoelectric conversion layer or other organic thin film layers and eject them. Therefore, the material that can be used as the electrode film is not particularly limited as long as it has a certain degree of conductivity, but it is preferably selected in consideration of adhesion, electron affinity, ionization potential, stability, etc. with the adjacent photoelectric conversion layer or other organic thin film layers. Examples of materials that can be used as the electrode film include conductive metal oxides such as tin oxide (NESA), indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, and tungsten; inorganic conductive substances such as copper iodide and copper sulfide; conductive polymers such as polythiophene, polypyrrole, and polyaniline; carbon, etc. These materials may be used by mixing a plurality of them as necessary, or a plurality of them may be laminated in two or more layers and used. The conductivity of the material used for the electrode film is not particularly limited as long as it does not unduly interfere with the light reception of the organic optoelectronic conversion element, but it is preferably as high as possible from the viewpoints of the signal intensity and power consumption of the organic optoelectronic conversion element. For example, an ITO film having conductivity with a sheet resistance value of 300 Ω / square or less can function sufficiently as the electrode film, but since commercially available substrates equipped with ITO films having conductivity of about several Ω / square are also available, it is desirable to use such a highly conductive substrate. The thickness of the ITO film (electrode film) can be arbitrarily selected in consideration of conductivity, but it is usually about 5 to 500 nm, preferably about 10 to 300 nm. Examples of methods for forming a film such as ITO include conventionally known vapor deposition methods, electron beam methods, sputtering methods, chemical reaction methods, and coating methods. The ITO film provided on the substrate may be subjected to UV-ozone treatment, plasma treatment, etc. as necessary.

[0081] Among the electrode films, as the material of the transparent electrode film used for at least one side where light is incident, examples include ITO, IZO, SnO2, ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO2, and FTO (fluorine-doped tin oxide). The transmittance of light incident through the transparent electrode film at the absorption peak wavelength of the photoelectric conversion layer is preferably 60% or more, more preferably 80% or more, and particularly preferably 95% or more.

[0082] In addition, when a plurality of photoelectric conversion layers with different detection wavelengths are stacked, the electrode films used between the respective photoelectric conversion layers (which are electrode films other than the pair of electrode films described above) need to transmit light with wavelengths other than the light detected by each photoelectric conversion layer. It is preferable to use a material that transmits 90% or more of the incident light for this electrode film, and more preferably a material that transmits 95% or more of the light.

[0083] The electrode film is preferably formed without plasma. By forming these electrode films without plasma, the influence of plasma on the substrate on which the electrode film is provided can be reduced, and the photoelectric conversion characteristics of the photoelectric conversion element can be improved. Here, "without plasma" means that plasma does not occur during the film formation of the electrode film, or the distance from the plasma generation source to the substrate is 2 cm or more, preferably 10 cm or more, and more preferably 20 cm or more, meaning a state in which the plasma reaching the substrate is reduced.

[0084] Examples of the apparatus that does not generate plasma during the film formation of the electrode film include an electron beam evaporation apparatus (EB evaporation apparatus) and a pulsed laser deposition apparatus. The method of forming a transparent electrode film using an EB evaporation apparatus is called the EB evaporation method, and the method of forming a transparent electrode film using a pulsed laser deposition apparatus is called the pulsed laser deposition method.

[0085] Examples of the apparatus that can achieve a state where plasma can be reduced during film formation include a facing target type sputtering apparatus and an arc plasma evaporation apparatus.

[0086] When a transparent conductive film is used as an electrode film (for example, a first conductive film), DC short circuit or an increase in leakage current may occur. One of the causes is considered to be that fine cracks generated in the photoelectric conversion layer are covered by a dense film such as TCO (Transparent Conductive Oxide), increasing the conduction between the electrode film on the side opposite to the transparent conductive film. Therefore, when a material with relatively poor film quality such as Al is used for the electrode, an increase in leakage current is less likely to occur. By controlling the film thickness of the electrode film according to the film thickness of the photoelectric conversion layer (depth of the crack), an increase in leakage current can be suppressed.

[0087] Normally, when the conductive film is made thinner than a predetermined value, a sharp increase in resistance value occurs. The sheet resistance of the conductive film in the organic optoelectronic conversion element for a photosensor of the present embodiment is usually 100 to 10,000 Ω / sq, and the degree of freedom of the film thickness is large. Also, the thinner the transparent conductive film, the less light it absorbs, and generally the light transmittance becomes higher. When the light transmittance becomes higher, the light absorbed by the photoelectric conversion layer increases and the photoelectric conversion ability is improved, which is very preferable.

[0088] The photoelectric conversion part of the organic optoelectronic conversion element of the present invention may include a photoelectric conversion layer and an organic thin film layer other than the photoelectric conversion layer. An organic semiconductor film is generally used for the photoelectric conversion layer constituting the photoelectric conversion part, but the organic semiconductor film may be a single layer or multiple layers. In the case of a single layer, a P-type organic semiconductor film, an N-type organic semiconductor film, or a mixed film thereof (bulk heterojunction structure) is used. On the other hand, in the case of multiple layers, it is about 2 to 10 layers, and it has a structure in which any one of a P-type organic semiconductor film, an N-type organic semiconductor film, or a mixed film thereof (bulk heterojunction structure) is laminated, and a buffer layer may be inserted between the layers. The thickness of the photoelectric conversion layer is usually 50 to 500 nm.

[0089] For the organic semiconductor film of the photoelectric conversion layer, depending on the wavelength band to be absorbed, triarylamine compounds, benzidine compounds, pyrazoline compounds, styrylamine compounds, hydrazone compounds, triphenylmethane compounds, carbazole compounds, polysilane compounds, thiophene compounds, phthalocyanine compounds, cyanine compounds, merocyanine compounds, oxonol compounds, polyamine compounds, indole compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, carbazole derivatives, naphthalene derivatives, anthracene derivatives, chrysene derivatives, phenanthrene derivatives, pentacene derivatives, phenylbutadiene derivatives, styryl derivatives, quinoline derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives, quinacridone derivatives, coumarin derivatives, porphyrin derivatives, fullerene derivatives, metal complexes (such as Ir complexes, Pt complexes, Eu complexes), etc. can be used. It functions as a P-type organic semiconductor or an N-type organic semiconductor in combination with the condensed polycyclic aromatic compound of the present invention.

[0090] When the condensed polycyclic aromatic compound of the present invention is used as the photoelectric conversion layer, it preferably has a HOMO (Highest Occupied Molecular Orbital) level shallower than the HOMO level of the aforementioned combined organic semiconductor. Thereby, in addition to suppressing the generation of dark current, it becomes possible to improve the photoelectric conversion efficiency.

[0091] In the organic photoelectric conversion element of the present invention, the organic thin film layer other than the photoelectric conversion layer constituting the photoelectric conversion unit is also used as a layer other than the photoelectric conversion layer, for example, an electron transport layer, a hole transport layer, an electron blocking layer, a hole blocking layer, a crystallization prevention layer, or an interlayer contact improvement layer, etc. In particular, by using it as one or more thin film layers selected from the group consisting of an electron transport layer, a hole transport layer, an electron blocking layer, and a hole blocking layer, an element that can efficiently convert into an electrical signal even with weak light energy can be obtained, which is preferable.

[0092] The electron transport layer serves to transport the electrons generated in the photoelectric conversion layer to the electrode film and to block the movement of holes from the electrode film where the electrons are transported to the photoelectric conversion layer. The hole transport layer serves to transport the generated holes from the photoelectric conversion layer to the electrode film and to block the movement of electrons from the electrode film where the holes are transported to the photoelectric conversion layer. The electron blocking layer serves to prevent the movement of electrons from the electrode film to the photoelectric conversion layer, prevent recombination within the photoelectric conversion layer, and reduce the dark current. The hole blocking layer has the function of preventing the movement of holes from the electrode film to the photoelectric conversion layer, preventing recombination within the photoelectric conversion layer, and reducing the dark current. The hole blocking layer is formed by laminating or mixing a hole blocking substance alone or two or more kinds thereof. The hole blocking substance is not limited as long as it is a compound capable of blocking the outflow of holes from the electrode to the outside of the element. Examples of the compound that can be used for the hole blocking layer include phenanthroline derivatives such as bathophenanthroline and bathocuproine, silole derivatives, quinolinol derivative metal complexes, oxadiazole derivatives, oxazole derivatives, quinoline derivatives, etc. Among these, one or more kinds can be used.

[0093] FIG. 3 shows a representative element structure of the organic optoelectronic conversion element of the present invention, but the present invention is not limited to this structure. In the embodiment example of FIG. 3, 1 represents an insulating layer, 2 represents one electrode film, 3 represents an electron blocking layer, 4 represents a photoelectric conversion layer, 5 represents a hole blocking layer, 6 represents the other electrode film, and 7 represents an insulating substrate or another organic optoelectronic conversion element, respectively. Although a transistor for reading is not shown in the figure, it may be connected to the electrode film of 2 or 6. Further, if the photoelectric conversion layer 4 is transparent, it may be formed on the outside of the electrode film on the side opposite to the side where light is incident. The light can be incident on the optoelectronic conversion element from either the upper or lower side as long as the components other than the photoelectric conversion layer 4 do not extremely inhibit the incidence of light having the main absorption wavelength of the photoelectric conversion layer.

Examples

[0094] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" represents "parts by mass" unless otherwise specified, and "%" represents "mass %". "M" represents molar concentration. Also, unless otherwise specified, the internal temperature within the reaction system is described as the reaction temperature.

[0095] In the examples, EI-MS was measured using ISQ7000 manufactured by Thermo Scientific, thermal analysis measurement was performed using TGA / DSC1 manufactured by Metrohm, and nuclear magnetic resonance (NMR) was measured using JNM-EC400 manufactured by JEOL Ltd. The mobility of the field-effect transistor was evaluated using B1500 or 4155C, which are mobility evaluation semiconductor parameters manufactured by Agilent. The surface of the organic thin film was observed using an atomic force microscope (hereinafter, AFM) AFM5400L manufactured by Hitachi High-Technologies Corporation. The application measurement of the current-voltage of the organic optoelectronic conversion element in the examples was performed using a semiconductor parameter analyzer 4200-SCS (manufactured by Keysight Technologies). The irradiation of the incident light was performed by PVL-3300 (manufactured by Asahi Spectra Co., Ltd.) at an irradiation light half-value width of 20 nm. The light-to-dark ratio in the examples means the current when light irradiation is performed divided by the current in the dark.

[0096] Example 1 (Synthesis of a condensed polycyclic aromatic compound represented by Specific Example No. 5) (Step 1) Synthesis of 2-(benzo[1,2-b:5,4-b']dithiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane Benzothieno[3,2-b][1]benzothiophene (5.0 parts) synthesized by a known method in THF (140 parts) was mixed, and 2.8 M normal butyllithium (10.4 parts) was added at -75 °C under a nitrogen atmosphere, followed by stirring for 1 hour. Then, isopropoxypinacol boronic acid (5.8 parts) was added at -75 °C, stirred for 30 minutes, heated to 20 °C, and further stirred for 2 hours. The resulting reaction solution was quenched with water (100 parts) and extracted by liquid separation using chloroform. The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: toluene) and further recrystallized from toluene to obtain 2-(benzothieno[3,2-b][1]benzothiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.6 parts, yield 45%).

[0097] (Step 2) Synthesis of 2,7-bis(benzothieno[3,2-b][1]benzothiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene In DMF (300 parts), water (12 parts), 2,7-diiodo[1]benzothieno[3,2-b][1]benzothiophene (1.9 parts) synthesized by the method described in Patent No. 4945757, 2-(benzothieno[3,2-b][1]benzothiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.6 parts) obtained in Step 1, tripotassium phosphate (3.2 parts), bis(dibenzylideneacetone)palladium(0) (0.13 part), and dicyclohexyl(2’,4’,6’-triisopropyl-[1,1’-biphenyl]-2-yl)phosphine (XPhos) (0.22 part) were mixed and stirred at 80 °C for 6 hours under a nitrogen atmosphere. After the resulting reaction solution was cooled to room temperature, water (300 parts) was added, and the solid content was collected by filtration. The obtained solid content was washed with acetone, dried, and then sublimation purification was performed to obtain the compound represented by No. 5 in the above specific example (0.6 part, yield 26%).

[0098] The results of EI-MS and thermal analysis measurements of the compound represented by No. 5 in the specific example obtained above were as follows. EI-MS m / z: Calcd for C 34 H 16 S6[M + : 615.96. Found: 616.10 Thermal analysis (endothermic peak): No endothermic peak up to 550 °C (under nitrogen atmosphere conditions)

[0099] Example 2 (Synthesis of the condensed polycyclic aromatic compound represented by Specific Example No. 14) (Step 3) Synthesis of 2-(benzo[1,2-b:4,5-b']dithiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane Benzo[1,2-b:4,5-b']dithiophene (5.0 parts) synthesized by a known method was mixed with THF (140 parts), and 2.8 M normal butyllithium (10.4 parts) was added at -75 °C under a nitrogen atmosphere, followed by stirring for 1 hour. Then, isopropoxypinacol borate (5.8 parts) was added at -75 °C, and the mixture was stirred for 30 minutes. After warming to 20 °C, stirring was continued for another 2 hours. The resulting reaction solution was quenched with water (100 parts) and extracted by liquid separation using chloroform. The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: toluene) and further recrystallized from toluene to obtain 2-(benzo[1,2-b:4,5-b']dithiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.6 parts, yield 45%).

[0100] (Step 4) Synthesis of 2,7-bis(benzo[1,2-b:4,5-b']dithiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene To DMF (300 parts), water (12 parts), synthesized by the method described in Patent No. 4945757 2,7-Diiodo[1]benzothieno[3,2-b][1]benzothiophene (1.9 parts), 2-(benzo[1,2-b:4,5-b']dithiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.6 parts) obtained in Step 3, tripotassium phosphate (3.2 parts), bis(dibenzylideneacetone)palladium(0) (0.13 part) and dicyclohexyl(2',4',6'-triisopropyl-[1,1'-biphenyl]-2-yl)phosphine (XPhos) (0.22 part) were mixed and stirred at 80°C for 6 hours under a nitrogen atmosphere. After cooling the resulting reaction solution to room temperature, water (300 parts) was added and the solid content was separated by filtration. The obtained solid content was washed with acetone and dried, and then sublimation purification was carried out to obtain the compound represented by No. 14 of the above specific example (0.9 part, yield 40%).

[0101] The results of EI-MS and thermal analysis measurements of the compound represented by No. 14 of the specific example obtained above were as follows. EI-MS m / z : Calcd for C 34 H 16 S6[M + : 615.96. Found: 616.20 Thermal analysis (endothermic peak): No endothermic peak up to 550°C (under nitrogen atmosphere conditions)

[0102] Example 3 (Fabrication of the field effect transistor of the present invention) On an n-doped silicon wafer with a Si thermal oxide film surface-treated with 1,1,1,3,3,3-hexamethyldisilazane, a condensed polycyclic aromatic compound represented by No. 5 of the specific example obtained in Example 1 was formed into a 100-nm film by resistance heating vacuum evaporation. Next, Au was vacuum-evaporated onto the organic thin film obtained above using a shadow mask, and a source electrode and a drain electrode with a channel length of 20 to 200 μm and a channel width of 2000 μm were respectively fabricated to produce the top-contact type field-effect transistor (FET) element 1 of the present invention (the configuration is shown in Fig. 1B). In the field-effect transistor element 1, the thermal oxide film in the n-doped silicon wafer with the thermal oxide film has the function of an insulating layer, and the n-doped silicon wafer has the functions of a substrate and a gate electrode.

[0103] Example 4 (Fabrication of the field-effect transistor of the present invention) A field-effect transistor (FET) element 2 of the present invention was fabricated in the same manner as in Example 3, except that the condensed aromatic compound represented by No. 5 of the specific example obtained in Example 1 was changed to the compound represented by the following formula (x) synthesized by the method described in JP-A-2018-014474.

[0104] Comparative Example 1 (Fabrication of a comparative field-effect transistor) A comparative field-effect transistor (FET) element 3 was fabricated in the same manner as in Example 3, except that the condensed polycyclic aromatic compound represented by No. 5 of the specific example obtained in Example 1 was changed to the compound represented by the following formula (x) synthesized by the method described in JP-A-2018-014474.

[0105]

Chemical formula

[0106] (Heat resistance test of the field-effect transistor element) The performance of a field-effect transistor element depends on the amount of current flowing when a potential is applied between the source electrode and the drain electrode while a potential is applied to the gate. By using the measurement result of this current value in the following formula (a) that expresses the electrical characteristics of the carrier species generated in the semiconductor layer, the mobility can be calculated. 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 the mobility to be determined (cm 2 / Vs). Ci is the dielectric constant of the SiO2 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 field-effect transistor device, and Vt can be obtained from Id and Vg. By substituting each value into formula (a), the mobility at each gate potential can be calculated.

[0107] Three field-effect transistor elements were respectively fabricated on one substrate by a method according to Example 3, 4 and Comparative Example 1, and after heating at 120 °C for 30 minutes under atmospheric pressure, the carrier mobility μ was measured by the above method. Next, the field-effect transistor elements 1 to 3 used for measuring the carrier mobility μ after heating at 120 °C were further heated at 150 °C for 30 minutes under atmospheric pressure, and then the carrier mobility μ was measured by the above method. Finally, the field-effect transistor elements 1 to 3 used for measuring the carrier mobility μ after heating at 150 °C were further heated at 180 °C for 30 minutes under atmospheric pressure, and then the carrier mobility μ was measured by the above method. The criteria for judging heat resistance are as follows. The results are shown in Table 1. In addition, in Table 1, the parts where the field-effect transistor was broken before being subjected to heating and the test could not be carried out were marked as "-". · Judgment criteria A: The change rate of the mobility after heating based on the mobility immediately after fabricating the field-effect transistor is less than 30% B: The change rate of the mobility after heating based on the mobility immediately after fabricating the field-effect transistor is 30% or more C: The field-effect transistor element is damaged by heating and cannot be evaluated

[0108]

Table 1

[0109] (Heat resistance test of organic thin film) Using the condensed polycyclic aromatic compound represented by No. 5 of the specific example obtained in Example 1, the condensed polycyclic aromatic compound represented by No. 14 of the specific example obtained in Example 2, and the compound represented by formula (x), 100 nm organic thin films were respectively fabricated on an n-doped silicon wafer with a Si thermal oxide film surface-treated with 1,1,1,3,3,3-hexamethyldisilazane by the vapor deposition method described in Example 3. The obtained organic thin films were heated at 120 °C for 30 minutes under atmospheric pressure and then cooled to room temperature once, then heated at 150 °C for 30 minutes under atmospheric pressure and then cooled to room temperature once, and further heated at 180 °C for 30 minutes under atmospheric pressure and then cooled to room temperature. The average roughness (Ra) of the organic thin film immediately after fabrication and the average roughness (Ra) of the organic thin film after heating at 120 °C, 150 °C, and 180 °C were calculated using the AFM analysis program. The results are shown in Table 2. Also, the surface state of the organic thin film used for calculating the average roughness was observed by AFM (scanning range: 1 μm). The AFM of the organic thin film containing the condensed polycyclic aromatic compound represented by No. 5 of the specific example is shown in Figure 4, the AFM of the organic thin film containing the condensed polycyclic aromatic compound represented by No. 14 of the specific example is shown in Figure 5, and the AFM of the organic thin film containing the compound represented by formula (x) is shown in Figure 6.

[0110]

Table 2

[0111] From the results in Table 1, it is clear that the field-effect transistor of the present invention is superior in heat resistance to the comparative field-effect transistor. Also, from the results in Table 2, it can be seen that the change in the average roughness before and after the heating test of the organic thin film containing the condensed polycyclic aromatic compound of the present invention represented by No. 5 and No. 14 of the specific examples is smaller than that of the organic thin film containing the compound represented by the comparative formula (x). This is clear from the comparison between the images observed by AFM of the organic thin film containing the condensed polycyclic aromatic compound of the present invention shown in FIGS. 4 and 5 and the images observed by AFM of the organic thin film containing the compound represented by the comparative formula (x) shown in FIG. 6.

[0112] Example 5 (Production and evaluation of an organic optoelectronic conversion element of the compound represented by No. 5 of the specific example obtained in Example 1) On ITO transparent conductive glass (manufactured by Diomatech Co., Ltd., ITO film thickness 150 nm), the condensed polycyclic aromatic compound represented by No. 5 of the specific example obtained in Example 1 was formed into a film with a thickness of 90 nm by resistance heating vacuum evaporation. Next, aluminum was vacuum-deposited at 100 nm as an electrode to fabricate the organic optoelectronic conversion element of the present invention. When a voltage of 5 V was applied with ITO and aluminum as electrodes and light irradiation with an irradiation light wavelength of 460 nm was performed, the light-dark ratio was 4.4×10 5 It was.

[0113] Comparative Example 2 (Production and evaluation of a comparative organic optoelectronic conversion element) A comparative organic optoelectronic conversion element was fabricated and evaluated in the same manner as in Example 4, except that the condensed polycyclic aromatic compound represented by No. 5 of the specific example obtained in Example 1 was changed to the compound represented by the formula (x) synthesized by the method described in JP-A-2018-014474. The light-dark ratio was 3.8×10 4 It was.

[0114] Example 6 (Synthesis of the condensed polycyclic aromatic compound represented by No. 13 of the specific example) (Step 5) Synthesis of the intermediate compound represented by the following formula a Benzene[1,2-b:5,4-b']difuran (0.84 parts) synthesized by a known method in THF (30 parts) was mixed, and 1.6 M normal butyllithium (2.5 parts) was added at -75 °C under a nitrogen atmosphere, followed by stirring for 1 hour. Then, carbon tetrabromide (1.9 parts) was added at -75 °C, stirred for 10 minutes, warmed to 20 °C and further stirred for 30 minutes. The resulting reaction solution was quenched with water (30 parts) and separated and extracted with ethyl acetate. The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: hexane) to obtain an intermediate compound (1.1 parts, yield 87%) represented by the following formula a.

[0115] [Chemical formula]

[0116] (Step 6) Synthesis of the condensed polycyclic aromatic compound represented by No. 13 of the specific example In DMF (48 parts), water (2 parts), a compound (0.66 parts) represented by the following formula b synthesized by a known method, the intermediate compound (0.96 parts) represented by formula a obtained in Step 5, tripotassium phosphate (1.1 parts), and tetrakis(triphenylphosphine)palladium (0.09 parts) were mixed and stirred at 80 °C for 6 hours under a nitrogen atmosphere. The resulting reaction solution was cooled to room temperature, water (50 parts) was added, and the solid content was separated by filtration. The obtained solid content was washed with acetone, dried, and then sublimation purification was performed to obtain the compound (0.24 parts, yield 32%) represented by No. 13 of the above specific example.

[0117] [Chemical formula]

[0118] The results of EI-MS of the compound represented by No. 13 of the specific example obtained above were as follows. EI-MS m / z: Calcd for C 34 H 16 O4S2[M+]: 552.05. Found: 552.10

[0119] Example 7 (Synthesis of a Condensed Polycyclic Aromatic Compound with Phenyl Groups Substituted at Both Terminal Furanyl Rings of Specific Example No. 13) (Step 7) Synthesis of an Intermediate Compound Represented by the Following Formula c To THF (40 parts), the intermediate compound represented by Formula a obtained in Step 5 (1.5 parts), phenylboronic acid (0.94 part), and a 2M aqueous potassium carbonate solution (20 parts) were mixed and stirred under a nitrogen atmosphere. Tetrakis(triphenylphosphine)palladium (0.37 part) was added thereto, the temperature was raised to the reflux temperature, and the mixture was stirred for 3 hours. After completion of the reaction, ethyl acetate (30 parts) and water (30 parts) were added to the reaction solution for liquid separation, and the aqueous layer was extracted twice with ethyl acetate (50 parts). The obtained organic layer was dried using sodium sulfate, the solid was filtered off, and then the organic solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: chloroform) to obtain an intermediate compound represented by the following Formula c (1.2 parts, yield 78%).

[0120]

Chemical formula

[0121] (Step 8) Synthesis of an Intermediate Compound Represented by the Following Formula d The intermediate compound represented by Formula c obtained in Step 7 (1.1 part) was mixed with THF (24 parts), and 1.6M normal butyllithium (2.1 parts) was added at -75°C under a nitrogen atmosphere, followed by stirring for 1 hour. Thereafter, carbon tetrabromide (1.7 parts) was added at -75°C and stirred for 10 minutes, the temperature was raised to 20°C, and then the mixture was further stirred for 30 minutes. The obtained reaction solution was quenched with water (30 parts) and extracted twice with ethyl acetate (30 parts). The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: chloroform) to obtain an intermediate compound represented by the following Formula d (0.99 part, yield 64%).

[0122]

Chemical formula

[0123] (Project 9) Synthesis of the condensed polycyclic aromatic compound represented by the following Formula No. 13-Ph To DMF (54 parts), water (2 parts), the compound represented by the following Formula b synthesized by a known method (0.53 part), the intermediate compound represented by Formula d obtained in Step 8 (0.85 part), tripotassium phosphate (1.7 parts), and tetrakis(triphenylphosphine)palladium (0.16 part) were mixed, and the mixture was stirred at 80 °C for 5 hours under a nitrogen atmosphere. After the obtained reaction solution was cooled to room temperature, water (50 parts) was added, and the solid content was separated by filtration. The obtained solid content was washed with acetone and dried, and then sublimation purification was carried out to obtain the compound represented by the following Formula No. 13-Ph (0.33 part, yield 44%).

[0124]

Chemical formula

[0125] The results of EI-MS of the compound represented by Formula No. 13-Ph obtained above were as follows. EI-MS m / z : Calcd for C 46 H 24 O4S2[M+]: 704.11. Found: 704.18

[0126] Example 8 (Synthesis of the condensed polycyclic aromatic compound in which phenyl groups are substituted on both terminal thiophene rings of Specific Example No. 14) (Project 10) Synthesis of the intermediate compound represented by the following Formula f To THF (40 parts), the intermediate compound represented by Formula e (2.0 parts) obtained in the same manner as in Step 3, iodobenzene (1.6 parts), and 2M aqueous potassium carbonate solution (20 parts) were mixed and stirred under a nitrogen atmosphere. Tetrakis(triphenylphosphine)palladium (0.37 part) was added thereto, and the temperature was raised to the reflux temperature and stirred for 3 hours. After completion of the reaction, ethyl acetate (30 parts) and water (30 parts) were added to the reaction solution for liquid separation, and the aqueous layer was extracted twice with ethyl acetate. The obtained organic layer was dried over sodium sulfate, the solid was filtered off, and then the organic solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: chloroform) to obtain a compound represented by the following Formula f (1.3 parts, yield 80%).

[0127]

Chemical formula

[0128] (Step 11) Synthesis of an intermediate compound represented by the following Formula g To THF (45 parts), the intermediate compound represented by Formula f (1.2 parts, 4.51 mmol) obtained in Step 10 was mixed, and 1.6M normal butyllithium (2.0 parts) was added at -75°C under a nitrogen atmosphere and stirred for 1 hour. Then, pinacol isopropoxyboronate (0.92 part) was added at -75°C and stirred for 30 minutes. After the temperature was raised to 20°C, it was further stirred for 2 hours. The obtained reaction solution was quenched with a saturated aqueous ammonium chloride solution (50 parts) and subjected to liquid separation extraction with ethyl acetate. The obtained organic layer was dried over sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: chloroform) to obtain a compound represented by the following Formula g (0.97 part, yield 55%).

[0129]

Chemical formula

[0130] (Step 12) Synthesis of a condensed polycyclic aromatic compound represented by the following Formula No.14-Ph To DMF (43 parts), water (1.6 parts), the compound represented by the following formula h synthesized by a known method (0.43 part), the intermediate compound represented by formula g obtained in Step 11 (0.85 part, 2.17 mmol), tripotassium phosphate (1.4 parts), and tetrakis(triphenylphosphine)palladium (0.12 part) were mixed and stirred at 90 °C for 6 hours under a nitrogen atmosphere. After the obtained reaction solution was cooled to room temperature, water (50 parts) was added and the solid content was separated by filtration. After the obtained solid content was washed with acetone and dried, sublimation purification was performed to obtain the compound represented by the following formula No. 14-Ph (0.19 part, yield 29%).

[0131] [Chemical formula]

[0132] The results of EI-MS of the compound represented by formula No. 14-Ph obtained above were as follows. EI-MS m / z: Calcd for C 46 H 24 S6[M+]: 768.02. Found: 768.10

[0133] Example 9 (Synthesis of the condensed polycyclic aromatic compound represented by Specific Example No. 16) (Step 13) Synthesis of the intermediate compound represented by the following formula i Naphtho[2,3-b:6,7-b']difuran (1.0 part) synthesized by a known method was mixed into THF (50 parts), and 1.6 M normal butyllithium (2.2 parts) was added at -75 °C under a nitrogen atmosphere and stirred for 1 hour. Then, carbon tetrabromide (1.8 parts) was added at -75 °C and stirred for 10 minutes. After the temperature was raised to 20 °C, stirring was continued for another 30 minutes. The obtained reaction solution was quenched with water (30 parts) and extracted by liquid separation using ethyl acetate. The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: hexane) to obtain the compound represented by the following formula i (1.0 part, yield 73%).

[0134] [Chemistry]

[0135] (Engineering 14) Synthesis of the condensed polycyclic aromatic compound represented by No. 16 of the specific example To DMF (48 parts), water (2 parts), the compound represented by the following formula b synthesized by a known method (0.57 part), the intermediate compound represented by formula i obtained in Step 13 (1.0 part), tripotassium phosphate (1.0 part), and tetrakis(triphenylphosphine)palladium (0.09 part) were mixed and stirred at 80 °C for 6 hours under a nitrogen atmosphere. After the obtained reaction solution was cooled to room temperature, water (50 parts) was added and the solid content was collected by filtration. The obtained solid content was washed with acetone, dried, and then purified by sublimation to obtain the compound represented by No. 16 of the above specific example (0.27 part, yield 34%).

[0136] [Chemistry]

[0137] The results of EI-MS of the compound represented by No. 16 of the specific example obtained above were as follows. EI-MS m / z: Calcd for C 42 H 20 O4S2[M+]: 652.08. Found: 652.27

[0138] Example 10 (Synthesis of the condensed polycyclic aromatic compound represented by No. 17 of the specific example) (Engineering 15) Synthesis of the intermediate compound represented by the following formula j Naphtho[2,3-b:6,7-b']difuran (1.5 parts), synthesized by a known method in THF (50 parts), was mixed, and 1.6 M normal butyllithium (2.9 parts) was added at -75 °C under a nitrogen atmosphere and stirred for 1 hour. Then, carbon tetrabromide (2.3 parts) was added at -75 °C and stirred for 10 minutes. After warming to 20 °C, stirring was continued for another 30 minutes. The resulting reaction solution was quenched with water (30 parts) and separated and extracted with ethyl acetate. The obtained organic layer was dried using sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained solid was purified by a silica gel column (developing solvent: hexane) to obtain an intermediate compound (1.3 parts, yield 64%) represented by the following formula j.

[0139] [Chemical formula]

[0140] (Step 16) Synthesis of the condensed polycyclic aromatic compound represented by No. 17 of the specific example To DMF (48 parts), water (2 parts), the compound represented by the following formula b synthesized by a known method (0.37 part), the intermediate compound represented by formula j obtained in Step 15 (0.7 part), tripotassium phosphate (0.6 part), and tetrakis(triphenylphosphine)palladium (0.05 part) were mixed and stirred at 80 °C for 6 hours under a nitrogen atmosphere. After cooling the resulting reaction solution to room temperature, water (50 parts) was added, and the solid content was separated by filtration. The obtained solid content was washed with acetone, dried, and then sublimation purification was performed to obtain the compound represented by No. 17 of the above specific example (0.13 part, yield 24%).

[0141] [Chemical formula]

[0142] The results of EI-MS of the compound represented by No. 17 of the specific example obtained above were as follows. EI-MS m / z: Calcd for C 42 H 20 S6[M+]: 715.99. Found: 716.14

[0143] Example 11 (Fabrication of the Field-Effect Transistor of the Present Invention) The field-effect transistor (FET) element 4 of the present invention was fabricated in the same manner as in Example 3, except that the condensed aromatic compound represented by No. 5 of the specific example obtained in Example 1 was changed to the compound represented by No. 13 of the specific example obtained in Example 6.

[0144] Example 12 (Fabrication of the Field-Effect Transistor of the Present Invention) The field-effect transistor (FET) element 5 of the present invention was fabricated in the same manner as in Example 3, except that the condensed aromatic compound represented by No. 5 of the specific example obtained in Example 1 was changed to the compound represented by No. 13-Ph obtained in Example 7.

[0145] (Heat Resistance Test of the Field-Effect Transistor Element) The heat resistance tests of the field-effect transistor elements 4 and 5 were performed in the same manner and according to the same criteria as those for the field-effect transistor elements 1 to 3. The results are shown in Table 3.

[0146]

Table 3

[0147] (Heat Resistance Test of the Organic Thin Film) Using the condensed polycyclic aromatic compound represented by No. 13 of the specific example obtained in Example 6 and the condensed polycyclic aromatic compound represented by No. 13-Ph obtained in Example 7, 100-nm organic thin films were respectively fabricated on an n-doped silicon wafer with an Si thermal oxide film surface-treated with 1,1,1,3,3,3-hexamethyldisilazane by the vapor deposition method described in Example 3. After heating the obtained organic thin films at 120 °C for 30 minutes under atmospheric pressure and then cooling to room temperature once, then heating at 150 °C for 30 minutes under atmospheric pressure and then cooling to room temperature once, and further heating at 180 °C for 30 minutes under atmospheric pressure and then cooling to room temperature, the average roughness (Ra) immediately after fabricating the organic thin films and the average roughness (Ra) of the organic thin films after heating at 120 °C, 150 °C, and 180 °C were calculated using the analysis program of AFM. The results are shown in Table 4. Also, the surface state of the organic thin films used for calculating the average roughness was observed by AFM (scanning range: 1 μm). The AFM of the organic thin film containing the condensed polycyclic aromatic compound represented by No. 13 of the specific example is shown in Fig. 7, and the AFM of the organic thin film containing the condensed polycyclic aromatic compound represented by No. 13-Ph is shown in Fig. 8, respectively.

[0148]

Table 4

[0149] From the results in Table 3, it is clear that the field-effect transistor of the present invention is superior in heat resistance to the comparative field-effect transistor (see Table 1). Also, from the results in Table 4, it can be seen that the change in the average roughness before and after the heating test of the organic thin films containing the condensed polycyclic aromatic compounds of the present invention represented by No. 13 and No. 13-Ph of the specific examples is smaller than that of the organic thin films containing the compound represented by the comparative formula (x) (see Table 2). This is clear from the comparison between the images observed by AFM of the organic thin films containing the condensed polycyclic aromatic compounds of the present invention shown in Figs. 7 and 8 and the images observed by AFM of the organic thin films containing the compound represented by the comparative formula (x) shown in Fig. 6.

[0150] Example 13 (Fabrication and Evaluation of Organic Photoelectric Conversion Element of Compound Represented by No. 13 in Specific Example Obtained in Example 6) An organic photoelectric conversion element of the present invention was fabricated and evaluated in the same manner as in Example 5, except that the condensed polycyclic aromatic compound represented by No. 5 in the specific example obtained in Example 1 was changed to the compound represented by No. 13 in the specific example obtained in Example 6. The light-dark ratio was 5.4×10 4 .

[0151] Example 14 (Fabrication and Evaluation of Organic Photoelectric Conversion Element of Compound Represented by No. 13-Ph Obtained in Example 7) An organic photoelectric conversion element of the present invention was fabricated and evaluated in the same manner as in Example 5, except that the condensed polycyclic aromatic compound represented by No. 5 in the specific example obtained in Example 1 was changed to the compound represented by No. 13-Ph obtained in Example 7. The light-dark ratio was 5.0×10 4 .

Industrial Applicability

[0152] According to the present invention, it is possible to provide a condensed polycyclic aromatic compound excellent in heat resistance in a practical process temperature range, an organic thin film containing the compound, and an organic semiconductor device (field effect transistor, organic photoelectric conversion element) having the organic thin film.

Claims

1. A substituent represented by the general formula (1) 【Chemical 1】 (In formula (1), R １ and R ２ one of the formulas is general formula (2) or (3) [Chemical Formula 2] (In Formulas (2) and (3), n represents 1. X represents an oxygen atom, a sulfur atom, or a selenium atom. In Formula (2), R ３ represents a phenyl group, a biphenyl group, or a naphthyl group. In Formula (3), R ３ represents a phenyl group, a biphenyl group, or a naphthyl group.) represents a substituent, and the other represents a hydrogen atom.) A condensed polycyclic aromatic compound represented by

2. R in formula (2) and formula (3) ３ The condensed polycyclic aromatic compound according to claim 1, wherein R is a phenyl group.

3. R １ and R ２ The condensed polycyclic aromatic compound according to claim 1 or 2, wherein one of them is a substituent represented by the general formula (2).

4. R １ and R ２ The condensed polycyclic aromatic compound according to claim 1 or 2, wherein one of them is a substituent represented by the general formula (3).

5. The condensed polycyclic aromatic compound according to any one of Claims 1 to 4, wherein X is an oxygen atom or a sulfur atom.

6. A material for an organic optoelectronic conversion element containing the condensed polycyclic aromatic compound according to any one of Claims 1 to 5.

7. An organic thin film containing the condensed polycyclic aromatic compound according to any one of Claims 1 to 5.

8. A field effect transistor having the organic thin film according to Claim 7.

9. An organic optoelectronic conversion element having the organic thin film according to Claim 7.

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