JP7317301B2 - Organic semiconductor compound and its use - Google Patents

Description

The present invention relates to organic semiconductor compounds and uses thereof. More specifically, the present invention relates to dinaphtho[3,2-b:2',3'-f]thieno[3,2-b]thiophene (hereinafter abbreviated as "DNTT") derivatives and their uses.

In recent years, thin film devices using organic semiconductors, such as organic FET (field effect transistor) devices and organic EL (electroluminescence) devices, have attracted attention and have been put to practical use. Various compounds have been researched and developed as organic semiconductor materials used in these thin film devices. is shown. However, the DNTT derivatives disclosed in Patent Literatures 1 and 2 have poor solubility in organic solvents, and the problem is that an organic semiconductor layer cannot be produced by a solution process such as a coating method.

Regarding this problem, Patent Document 3 and Non-Patent Document 1 show that the solubility in organic solvents is improved by introducing a branched alkyl group into the DNTT skeleton, but the solubility is 1 g/ It is less than L and cannot be said to be sufficient.
In addition, in Patent Document 4, although the solubility is improved by introducing alkyl groups at the 5 and 12 positions near the thiophene ring of the DNTT skeleton, the carrier mobility is greatly reduced due to disordered molecular orientation. .

WO2008/050726 WO2010/098372 WO2014/115749 WO2014/027685

ACS Appl. Mater. Interfaces, 8, 3810-3824 (2016)

The DNTT derivatives disclosed in Patent Documents 1 to 3 and Non-Patent Document 1 do not have sufficient solubility in organic solvents. The DNTT derivative disclosed in Patent Document 4 has excellent solubility in organic solvents, but does not have sufficient carrier mobility.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic semiconductor material for solution processing, which is excellent in solubility in organic solvents and can be used for manufacturing an organic semiconductor layer by a solution process such as a coating method. and

As a result of intensive studies, the present inventors have found that an organic semiconductor compound having a specific structure can solve the above problems, and have completed the present invention.
That is, the present invention
[1] Formula (1) below

(In formula (1), m and n each independently represent an integer of 1 to 10, L is the following formulas (2) to (6)

Represents a divalent linking group or a divalent linking group in which any two of formulas (2) to (6) are bonded, and R represents an alkyl group or an aromatic group) represented by an organic semiconductor compound,
[2] The organic semiconductor compound according to [1] above, wherein m is 3 and n is 2;
[3] The organic semiconductor compound according to the preceding item [1] or [2], wherein R is a methyl group;
[4] An organic semiconductor material containing the organic semiconductor compound according to any one of [1] to [3] above,
[5] An organic thin film made of the organic semiconductor material according to [4] above,
[6] An organic electronic device comprising the organic thin film according to [5] above, and [7] A step of applying an organic solvent solution of the organic semiconductor material according to [4] above to a substrate to provide an organic semiconductor solution layer and a method for forming an organic thin film, which includes the step of removing the organic solvent from the organic semiconductor solution layer;
Regarding.

The organic semiconductor material according to the present invention is highly soluble in organic solvents. Therefore, it is possible to reduce the amount of solvent used in solution processes such as coating methods, and because the effect of steric hindrance of substituents on molecular orientation is small, it is possible to form an organic semiconductor layer that exhibits good carrier mobility. be.

FIG. 1 is a schematic cross-sectional view showing some embodiments of the structure of the organic thin film transistor (element) of the present invention, where A is a bottom contact-bottom gate type organic thin film transistor (element), and B is a top contact-bottom gate type. Organic thin film transistor (device), C is top contact-top gate type organic thin film transistor (device), D is top and bottom gate type organic thin film transistor (device), E is static induction transistor (device), F is bottom contact-top gate type organic thin film transistor (device). FIG. 2 is an explanatory diagram for explaining the manufacturing process of a top-contact-bottom-gate organic thin-film transistor (element) as one embodiment of the organic thin-film transistor (element) of the present invention, and (1) to (6) are It is a schematic sectional drawing which shows each process.

The present invention is described below.
The organic semiconductor compound of the present invention is represented by the above general formula (1).

In general formula (1), m and n each independently represent an integer of 1 to 10.
m in the general formula (1) is preferably 1 to 5, more preferably 2 to 4, and still more preferably 3.
n in the general formula (1) is preferably 1 to 5, more preferably 2 to 4, and still more preferably 2.

In the general formula (1), L is a divalent linking group represented by any one of the general formulas (2) to (6), or a divalent in which any two of the formulas (2) to (6) are bonded represents a linking group.

In general formula (1), R represents an alkyl group or an aromatic group.
The alkyl group represented by R in formula (1) is preferably a linear or branched alkyl group, more preferably a linear alkyl group. The number of carbon atoms in the alkyl group represented by R is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1.
The aromatic group represented by R in formula (1) is preferably an aromatic hydrocarbon group or a heterocyclic group, more preferably an aromatic hydrocarbon group.
Specific examples of the aromatic hydrocarbon group represented by R in the general formula (1) include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group and a benzopyrenyl group, preferably a phenyl group or a naphthyl group. A phenyl group is more preferred.
Specific examples of the heterocyclic group represented by R in formula (1) include a pyridyl group, a pyrazyl group, a pyrimidyl group, a quinolyl group, an isoquinolyl group, a pyrrolyl group, an indolenyl group, an imidazolyl group, a carbazolyl group, a thienyl group, and a furyl group. , pyranyl group, pyridonyl group, benzoquinolyl group, anthraquinolyl group, benzothienyl group, benzofuryl group and thienotienyl group, preferably pyridyl group, thienyl group, benzothienyl group or thienotienyl group, more preferably pyridyl group or thienyl group. .
The aromatic hydrocarbon group and heterocyclic group represented by R in the general formula (1) may have an alkyl group as a substituent, and the alkyl group which may have as the substituent may be a linear or branched chain. or alicyclic.

The organic semiconductor compound represented by the general formula (1) of the present invention can be synthesized, for example, based on the synthesis flow described in Non-Patent Document 1, using raw materials having corresponding substituents.

Moreover, the organic semiconductor compound represented by the general formula (1) is required to be soluble in an organic solvent. Any organic solvent can be used without particular limitation as long as it can dissolve the organic semiconductor compound represented by formula (1). Further, when considering the stability of the solution obtained by dissolving the organic semiconductor compound represented by the formula (1) in an organic solvent, the solubility of the organic semiconductor compound represented by the formula (1) at room temperature is higher than a certain level. is required. The solubility at 25° C. is usually 0.5 g/L or more, preferably 1.0 g/L or more, more preferably 2.0 g/L or more. As for the stability of the solution, it is preferable that no crystals precipitate even after 24 hours have passed since dissolution, and it is more preferable that the solution is completely dissolved even after one week has passed after dissolution.

Examples of organic solvents include halogen solvents such as chloroform, dichloromethane, chlorobenzene and dichlorobenzene; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, tetrahydronaphthalene and cyclohexylbenzene; diethyl ether, tetrahydrofuran, anisole and phenetole; and ethers such as butoxybenzene, amides such as dimethylacetamide, dimethylformamide and N-methylpyrrolidone, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone, acetonitrile, propionitrile and benzonitrile alcohols such as methanol, ethanol, isopropanol, butanol and cyclohexanol esters such as ethyl acetate, butyl acetate, ethyl benzoate and diethyl carbonate hydrocarbons such as hexane, octane, decane, cyclohexane and decalin etc. can be used.

The organic semiconductor material of the present invention contains an organic semiconductor compound represented by formula (1).
Although the content of the organic semiconductor compound represented by formula (1) in the organic semiconductor material is not particularly limited, it is usually about 50 to 100% by mass in the organic semiconductor material.

In addition to the organic semiconductor compound represented by the above formula (1), the organic semiconductor material of the present invention may optionally be used for the purpose of improving the characteristics of the organic semiconductor device and/or imparting other characteristics. The type of additive is not particularly limited as long as it does not inhibit the function as a semiconductor. For example, in addition to semiconducting materials and insulating materials having structures other than the formula (1) of the present invention, surfactants for controlling rheology, thickeners, dopants for adjusting carrier injection and carrier amount, etc. is an example. These are preferably those that do not impair the stability of the composition, and may be of high molecular weight or low molecular weight. The content of these additives varies depending on the purpose and cannot be generalized, but it is preferably less than the content of the organic semiconductor compound represented by formula (1).

The organic thin film of the present invention is obtained using an organic semiconductor material containing the organic semiconductor compound represented by Formula (1). The film thickness of the thin film varies depending on its use, but is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 300 nm.

The method for forming the organic thin film includes dry processes such as vapor deposition and various solution processes. However, it is possible to form the organic thin film by a solution process using an organic solvent solution in which the organic semiconductor material of the present invention is dissolved in an organic solvent. preferable. Organic solvents that can be used for the organic solvent solution include the same organic solvents as those described above.
Examples of solution processes include spin coating, drop casting, dip coating, spraying, flexographic printing, letterpress printing such as resin letterpress printing, offset printing, dry offset printing, and lithographic printing such as pad printing. , intaglio printing methods such as gravure printing methods, screen printing methods, mimeograph printing methods, stencil printing methods such as ring graph printing methods, inkjet printing methods, microcontact printing methods, etc., and methods in which a plurality of these methods are combined. . When forming a film by a solution process, it is preferable to form a thin film by evaporating the solvent after the coating and printing described above.

The organic semiconductor compound represented by Formula (1) is suitably used as a material for organic thin films of organic semiconductor devices such as organic EL elements, organic solar cell elements, organic photoelectric conversion elements and organic transistor elements. An organic transistor will be described in detail as an example.

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

The organic transistor will be described in more detail below using several embodiments of the organic transistor device shown in FIG. 1, but the invention is not limited to these structures.
1, 1 is a source electrode, 2 is a semiconductor layer, 3 is a drain electrode, 4 is an insulator layer, 5 is a gate electrode, and 6 is a substrate. The arrangement of each layer and electrodes can be appropriately selected according to the application of the device. A to D and F are called lateral transistors because the current flows parallel to the substrate. A is called a bottom contact bottom gate structure, and B is called a top contact bottom gate structure. In C, source and drain electrodes and an insulator layer are provided on a 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 type transistor. F is a bottom contact top gate structure. E is a schematic diagram of a transistor with a vertical structure, that is, a static induction transistor (SIT). In this SIT, a large amount of carriers can move at once because the current flow spreads in a plane. In addition, since the source electrode and the drain electrode are arranged vertically, the distance between the electrodes can be reduced, resulting in high speed response. Therefore, it can be preferably applied to applications such as high-speed switching and large current flow. Although E in FIG. 1 does not include a substrate, a substrate is usually provided outside the source or drain electrodes indicated by 1 and 3 in FIG. 1E.

Next, each component in each embodiment will be described.
The substrate 6 needs to be able to hold each layer formed thereon without peeling off. For example, insulating materials such as resin plates, films, paper, glass, quartz, and ceramics; objects in which an insulating layer is formed by coating or the like on a conductive substrate such as a metal or alloy; materials made of various combinations such as resins and inorganic materials; etc. can be used. Examples of usable resin films include polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyamide, polyimide, polycarbonate, cellulose triacetate and polyetherimide. The use of a resin film or paper makes the device flexible, lightweight, and practical. The thickness of the substrate is usually 1 μm to 10 mm, preferably 5 μm to 5 mm.

A material having conductivity is used for the source electrode 1 , the drain electrode 3 , and the gate electrode 5 . 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, etc. and alloys containing them; conductive oxides such as InO ₂ , ZnO ₂ , SnO ₂ and ITO; conductive high molecular compounds such as polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylenevinylene, and polydiacetylene; Semiconductors such as gallium arsenide; carbon materials such as carbon black, fullerene, carbon nanotubes, graphite and graphene; and the like can be used. Also, the conductive polymer compound and the semiconductor may be doped. Examples of dopants 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 and _FeCl3 ; halogen atoms such as iodine; metal atoms such as; Boron, phosphorus, arsenic and the like are also frequently used as dopants for inorganic semiconductors such as silicon.

A conductive composite material in which carbon black, metal particles, or the like is dispersed in the above dopant is also used. For the source electrode 1 and the drain electrode 3, which are in direct contact with the semiconductor, it is important to select an appropriate work function or perform surface treatment in order to reduce contact resistance.
Moreover, the distance (channel length) between the source electrode and the drain electrode is an important factor in determining device characteristics, and an appropriate channel length is required. If the channel length is short, the amount of current that can be extracted increases, but the short channel effect such as the influence of the contact resistance occurs, and the semiconductor characteristics may deteriorate. The channel length is typically 0.01 to 300 μm, preferably 0.1 to 100 μm. The width (channel width) between the source and drain electrodes is usually 10 to 5000 μm, preferably 40 to 2000 μm. In addition, it is possible to form a longer channel width by using a comb-shaped electrode structure. be.

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

In the case of the bottom contact structure, each electrode is generally fabricated using a lithographic method, and each electrode is preferably formed into a rectangular parallelepiped. Recently, the printing accuracy of various printing methods has been improved, and it has become possible to produce electrodes with high accuracy using techniques such as inkjet printing, gravure printing, and screen printing. In the case of a top contact structure in which an electrode is placed on a semiconductor, vapor deposition can be performed using a shadow mask or the like. It has also become possible to directly print an electrode pattern using a technique such as inkjet. The electrode length is the same as the channel width described above. Although the width of the electrode is not particularly defined, it is preferably as short as possible in order to reduce the area of the device as long as the electrical characteristics can be stabilized. The width of the electrodes is usually 0.1 to 1000 μm, preferably 0.5 to 100 μm. The thickness of the electrode is usually 0.5 to 1000 nm, preferably 1 to 500 nm, more preferably 5 to 200 nm. Wires are connected to the electrodes 1, 3, and 5, and the wires are also made of substantially the same material as the electrodes.

A material having an insulating property is used as the insulator layer 4 . For example, polyparaxylylene, polyacrylate, polymethylmethacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, polysiloxane, fluorine resin, epoxy resin, phenol resin, etc. and copolymers thereof; metal oxides such as silicon oxide, aluminum oxide, titanium oxide and tantalum oxide; ferroelectric metal oxides such as SrTiO ₃ and BaTiO ₃ ; nitrides such as silicon nitride and aluminum nitride Dielectrics such as sulfides, sulfides, and fluorides; or polymers in which particles of these dielectrics are dispersed; and the like can be used. For this insulator layer, one having high electrical insulation properties can be preferably used in order to reduce leakage current. As a result, the film thickness can be reduced, the insulation capacity can be increased, and more current can be taken out. Moreover, in order to improve the mobility of the semiconductor, it is preferable that the surface energy of the insulating layer surface is lowered and the film is smooth without unevenness. Therefore, a self-assembled monolayer or a two-layered insulator layer may be formed. The thickness of the insulator layer 4 varies depending on the material, but is usually 1 nm to 100 μm, preferably 5 nm to 50 μm, more preferably 5 nm to 10 μm.

As the material of the semiconductor layer 2, an organic semiconductor material containing at least one organic semiconductor compound represented by the above formula (1) can be used. The semiconductor layer 2 can be formed by forming an organic thin film containing the organic semiconductor compound represented by the formula (1) using the thin film forming method described above.
As for the semiconductor layer, a plurality of layers may be formed, but a single-layer structure is more preferable. It is preferable that the film thickness of the semiconductor layer 2 is as thin as possible as long as the necessary functions are not lost. In horizontal organic transistors as shown in A, B and D, the device characteristics do not depend on the film thickness if the film thickness exceeds a predetermined value, but leakage current often increases as the film thickness increases. It's for. The thickness of the semiconductor layer for exhibiting necessary functions is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 300 nm.

Other layers can be provided in the organic transistor, for example, between the substrate layer and the insulating film layer, between the insulating film layer and the semiconductor layer, or on the outer surface of the device, if necessary. For example, if a protective layer is formed directly on the organic semiconductor layer or via another layer, the influence of outside air such as humidity can be reduced. It also has the advantage of stabilizing the electrical characteristics, such as increasing the on/off ratio of the organic transistor device.
The material of the protective layer is not particularly limited, but examples include films made of various resins such as epoxy resin, acrylic resin such as polymethyl methacrylate, polyurethane, polyimide, polyvinyl alcohol, fluororesin, and polyolefin; silicon oxide, aluminum oxide, Inorganic oxide films such as silicon nitride films; films made of dielectric materials such as nitride films; Gas barrier protective materials developed for organic EL displays can also be used. Although the film thickness of the protective layer can be selected according to its purpose, it is usually 100 nm to 1 mm.

Further, by subjecting the substrate or insulator layer on which the organic semiconductor layer is to be laminated to surface modification or surface treatment in advance, it is possible to improve the characteristics as an organic transistor device. For example, by adjusting the degree of hydrophilicity/hydrophobicity of the substrate surface, it is possible to improve the film quality and film-forming properties of the film formed thereon. In particular, the properties of organic semiconductor materials may vary greatly depending on the state of the film, such as molecular orientation. Therefore, the surface treatment of the substrate, insulator layer, etc. controls the molecular orientation at the interface with the organic semiconductor layer to be formed later, or reduces the trap sites on the substrate or insulator layer. It is considered that the properties such as carrier mobility are improved by this.
Trap sites refer to functional groups, such as hydroxyl groups, present in the untreated substrate, the presence of such functional groups attracting electrons to the functional groups, resulting in reduced carrier mobility. . Therefore, reducing the number of trap sites is often effective in improving characteristics such as carrier mobility.

Examples of surface treatments for improving properties as described above include self-assembled monolayer treatments with hexamethyldisilazane, octyltrichlorosilane, octadecyltrichlorosilane, etc., surface treatments with polymers, etc., hydrochloric acid, sulfuric acid, acetic acid, etc. acid treatment, alkali treatment with sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc., ozone treatment, fluorination treatment, plasma treatment with oxygen, argon, etc., formation of Langmuir-Blodgett film, other insulators , semiconductor thin film forming treatment, mechanical treatment, electrical treatment such as corona discharge, rubbing treatment using fibers, etc., and a combination of these treatments can also be performed.
In these embodiments, for example, the above-described vacuum process and solution process can be appropriately adopted as a method of providing each layer such as a substrate layer and an insulating film layer or an insulating film layer and an organic semiconductor layer.

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

(Regarding organic transistor substrates and substrate processing)
The organic transistor of the present invention is produced by providing various necessary layers and electrodes on the substrate 6 (see FIG. 2(1)). As the substrate, those described above can be used. It is also possible to perform the aforementioned surface treatment on this substrate. It is preferable that the thickness of the substrate 6 be thin as long as the necessary functions are not hindered. Although it varies depending on the material, it is usually 1 μm to 10 mm, preferably 5 μm to 5 mm. Also, if necessary, the substrate can be made to function as an electrode.

(Formation of gate electrode)
A gate electrode 5 is formed on the substrate 6 (see FIG. 2(2)). As the electrode material, those described above are used. Various methods can be used as the method for forming the electrode film, and for example, a vacuum vapor deposition method, a sputtering method, a coating method, a thermal transfer method, a printing method, a sol-gel method, and the like are employed. During or after film formation, it is preferable to perform patterning as necessary so as to obtain a desired shape. As a patterning method, various methods can be used, and examples thereof include a photolithography method combining patterning of a photoresist and etching. In addition, we use vapor deposition methods using shadow masks, sputtering methods, printing methods such as inkjet printing, screen printing, offset printing, letterpress printing, soft lithography methods such as microcontact printing, and methods that combine multiple of these methods. and patterning is also possible. The film thickness of the gate electrode 5 varies depending on the material, but is usually 0.1 nm to 10 μm, preferably 0.5 nm to 5 μm, more preferably 1 nm to 3 μm. In addition, in the case of serving as both a gate electrode and a substrate, the film thickness may be larger than the above.

(Regarding the formation of the insulator layer)
An insulator layer 4 is formed on the gate electrode 5 (see FIG. 2(3)). As the insulator material, the 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, cast, bar coating, and blade coating, printing methods such as screen printing, offset printing, and inkjet, vacuum deposition, molecular beam epitaxial growth, ion cluster beam, and ion spray. Dry process methods such as a coating method, a sputtering method, an atmospheric pressure plasma method, and a CVD method can be used. In addition, a sol-gel method, a method of forming an oxide film on a metal such as alumite on aluminum and silicon oxide on silicon by thermal oxidation or the like is adopted. In the portion where the insulator layer and the semiconductor layer are in contact with each other, an insulator layer is used to orient the molecules constituting the semiconductor at the interface between the two layers, for example, the molecules of the organic semiconductor compound represented by the above formula (1). Certain surface treatments can also be applied to the layer. A surface treatment method similar to 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 to be taken out can be increased by increasing the electric capacity. At this time, if the film is thin, the leakage current increases, so it is preferable that the film is thin as long as the function is not impaired. It is usually 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, more preferably 5 nm to 10 μm.

(Regarding the formation of the organic semiconductor layer)
The organic semiconductor material containing the organic semiconductor compound represented by formula (1) of the present invention is used for forming an organic semiconductor layer (see FIG. 2(4)). Various methods can be used to form the organic semiconductor layer. Specifically, coating methods such as dip coating, die coater, roll coater, bar coater, and spin coat, ink jet, screen printing, offset printing, microcontact printing, and other solution process forming methods. is mentioned.

A method of forming a film by a solution process to obtain an organic semiconductor layer will be described. The organic semiconductor compound represented by the formula (1) of the present invention is dissolved in a solvent or the like, and if necessary, an additive or the like is added to the composition. ). Application methods include spin coating, drop casting, dip coating, spraying, flexographic printing, letterpress printing such as resin letterpress printing, offset printing, dry offset printing, and lithographic printing such as pad printing. , intaglio printing methods such as gravure printing methods, silk screen printing methods, mimeograph printing methods, stencil printing methods such as ring graph printing methods, inkjet printing methods, microcontact printing methods, etc., and methods combining a plurality of these methods. be done.
Furthermore, as a method similar to the coating method, the Langmuir project method in which the monomolecular film of the organic semiconductor layer prepared by dropping the above composition on the surface of water is transferred to a substrate and laminated, and two sheets of liquid crystal or melted material are applied. It is also possible to adopt a method of sandwiching between two substrates and introducing it between the substrates by capillarity.

The environment such as the temperature of the substrate and the composition during film formation is also important, and the characteristics of the transistor may change depending on the temperature of the substrate and the composition. Therefore, it is preferable to carefully select the temperature of the substrate and the composition. The substrate temperature is typically 0 to 200°C, preferably 10 to 120°C, more preferably 15 to 100°C. Care must be taken because it depends greatly on the solvent and the like in the composition used.
The film thickness of the organic semiconductor layer produced by this method is preferably as thin as possible within a range that does not impair the function. As the film thickness increases, there is a concern that leakage current will increase. The film thickness of the organic semiconductor layer is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 300 nm.

The characteristics of the organic semiconductor layer thus formed (see FIG. 2(4)) can be further improved by post-treatment. For example, heat treatment relaxes the strain in the film that occurred during film formation, reduces pinholes, etc., and allows the arrangement and orientation in the film to be controlled. can be improved. When fabricating the organic transistor of the present invention, it is effective to perform this heat treatment in order to improve the characteristics. The heat treatment is performed by heating the substrate after forming the organic semiconductor layer. Although the temperature of the heat treatment is not particularly limited, it is usually room temperature to about 150.degree. C., preferably 40 to 120.degree. C., more preferably 45 to 100.degree. The heat treatment time at this time is not particularly limited, but it is usually 10 seconds to 24 hours, preferably 30 seconds to 3 hours. The atmosphere at that time may be the air, or may be an inert atmosphere such as nitrogen or argon. In addition, it is possible to control the film shape by solvent vapor.

In addition, as another post-treatment method for the organic semiconductor layer, a characteristic change due to oxidation or reduction is induced by treating with an oxidizing or reducing gas such as oxygen or hydrogen, or an oxidizing or reducing liquid. You can also This can be used, for example, to increase or decrease the carrier density in the film.

Also, in a method called doping, the properties of the organic semiconductor layer can be changed by adding a trace amount of element, atomic group, molecule or polymer to the organic semiconductor layer. For example, acids such as oxygen, hydrogen, hydrochloric acid, sulfuric acid, and sulfonic acid; Lewis acids such as PF ₅ , AsF ₅ and FeCl ₃ ; halogen atoms such as iodine; metal atoms such as sodium and potassium; It can be doped with donor compounds such as phthalocyanines. This can be achieved by contacting the organic semiconductor layer with these gases, immersing it in a solution, or electrochemically doping it. These dopings are added during the synthesis of the organic semiconductor compound even after the preparation of the organic semiconductor layer, or added to the composition in the process of preparing the organic semiconductor layer using the composition for preparing the organic semiconductor device. It can be added during the process of forming a thin film. In addition, the material used for doping is added to the material forming the organic semiconductor layer at the time of vapor deposition and co-deposited, or it is mixed in the surrounding atmosphere during the preparation of the organic semiconductor layer (in an environment where the doping material is present). It is also possible to dope the film by bombarding the film with ions accelerated in vacuum.
These doping effects include a change in electrical conductivity due to an increase or decrease in carrier density, a change in carrier polarity (p-type, n-type), a change in the Fermi level, and the like.

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

(About protective layer)
Forming the protective layer 7 on the organic semiconductor layer has the advantage of minimizing the influence of outside air and stabilizing the electrical characteristics of the organic transistor (see FIG. 2(6)). As the material for the protective layer, those mentioned above are used. Any film thickness of the protective layer 7 can be adopted depending on the purpose, but it is usually 100 nm to 1 mm.
Various methods can be used to form the protective layer. When the protective layer is made of resin, for example, a resin solution is applied and then dried to form a resin film; a resin monomer is applied or vapor deposited. a method of polymerizing later; and the like. A cross-linking treatment may be performed after film formation. When the protective layer is made of an inorganic material, for example, a forming method using a vacuum process such as a sputtering method or a vapor deposition method, or a forming method using a solution process such as a sol-gel method can be used.
In the organic transistor, a protective layer can be provided not only on the organic semiconductor layer but also between each layer, if necessary. These layers may help stabilize the electrical properties of the organic transistor.

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

Organic transistors can also be used as digital devices and analog devices such as memory circuit devices, signal driver circuit devices, and signal processing circuit devices. Furthermore, by combining these, it becomes possible to manufacture displays, IC cards, IC tags, and the like. Furthermore, organic transistors can be used as sensors because their characteristics can be changed by external stimuli such as chemical substances.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
In the examples, the melting point is Optimelt MPA100 manufactured by Stanford Research Systems, the nuclear magnetic resonance spectrum is Avance500 manufactured by Bruker, the HR-MS is JMS-T100GCV manufactured by JEOL, and the elemental analysis is MT-6 CHN CORDER manufactured by Yanaco. was measured using
In addition, "part" in an Example means a mass part.

Example 1 (Synthesis of the organic semiconductor compound of the present invention represented by the following formula 7)
(Step 1) Synthesis of a compound represented by the following formula 1 In a 500 mL four-necked flask equipped with a dropping funnel and heated and dried, under a nitrogen atmosphere, 2,2,6,6-tetramethylpiperidine (TMP) 15.3 mL ( 90 mmol) was dissolved in 90 mL of tetrahydrofuran (THF). After cooling to −80° C., 58 mL of a 1.55 M hexane solution of normal-butyl lithium (n-BuLi) (molar number of normal-butyl lithium in the solution: 90 mmol) was slowly added dropwise. After stirring at -80°C for 10 minutes, 8.30 parts (22.5 mmol) of zinc chloride-tetramethylethylenediamine complex was added and the temperature was raised to 0°C. After stirring for 15 minutes, the mixture was cooled to -80°C again, and 7.11 parts (30.0 mmol) of 2-bromo-6-methoxynaphthalene was added. After the reaction solution was warmed to room temperature and stirred for 2 hours, 16.0 mL (180 mmol) of dimethyldisulfide (MeS-SMe) was added. After stirring for 17 hours, 2N hydrochloric acid was added, the reaction solution was extracted with ethyl acetate, the organic layer was dried over anhydrous magnesium sulfate, the reaction mixture was collected by filtration, and the solvent was distilled off using a rotary evaporator. The obtained reaction mixture was purified by silica gel chromatography using a mixed solvent of hexane:methylene chloride 8:2 as a mobile phase, and 6.23 parts (22.0 mmol, yield 73%) of a compound represented by the following formula 1 was obtained. was obtained as a white solid.

The results of melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis of the compound represented by formula 1 obtained in step 1 were as follows.
mp 86.2-86.8℃
¹ H NMR (CDCl ₃ , 400 MHz): δ (ppm) 7.85 (d, 1H, J = 1.6 Hz), 7.56 (d, 1H, J = 8.8 Hz), 7.43 (dd, 1H, J = 8.8, 2.0 Hz), 7.32 (s, 1H), 7.03 (s, 1H), 3.99 (s, 3H), 2.53 (s, 3H).
¹³ C NMR (CDCl ₃ , 100 MHz): δ (ppm) 154.63, 131.42, 130.40, 130.33, 128.52, 128.38, 128.07, 121.53, 117.59, 104.47, 55.93, 14.32.
HRMS (EI) m/z: Calcd for _C12H11BrOS [M] ⁺ : 281.9714. _Found : 281.9726.
Elemental analysis: Calcd for _{C12H11BrOS :} C, 50.90; H, 3.92. Found: C, 50.73; H, 3.85.

(Step 2) Synthesis of a compound represented by the following formula 2 In a 500 mL four-necked flask, 5.66 parts (20.0 mmol) of the compound represented by the formula 1 obtained in step 1 was dissolved in 150 mL of methylene chloride. rice field. At 0° C., 25 mL of a 1.0 M methylene chloride solution of boron tribromide (BBr ₃ ) (molar number of boron tribromide in the solution: 25 mmol) was slowly added dropwise. After stirring for 9 hours, the mixture was poured into ice water, the reaction solution was extracted with methylene chloride, the organic layer was dried over anhydrous magnesium sulfate, the reaction mixture was collected by filtration, and the solvent was distilled off using a rotary evaporator. The obtained reaction mixture was purified by recrystallization to obtain 5.28 parts (19.6 mmol, 98%) of the compound represented by the following formula 2 as a white solid.

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 2 obtained in step 2 were as follows.
mp 123.4-123.7℃
¹³ C NMR (CDCl ₃ , 100 MHz): δ (ppm) 152.87, 133.25, 132.37, 130.18, 129.92, 129.18, 128.09, 125.92, 117.40, 109.29, 19.53.
HRMS (EI) m/z: Calcd for _C11H9BrOS [M] ⁺ : 267,9558. _Found : 267.9574.
Elemental analysis: Calcd for _C11H9BrOS : C, 49.09; H, 3.37. Found: C, 48.99; H, 3.38 _.

(Step 3) Synthesis of a compound represented by the following formula 3 In a 500 mL four-necked flask, 5.20 parts (19.3 mmol) of the compound represented by the formula 2 obtained in step 2 was dissolved in 120 mL of methylene chloride. rice field. After adding 6.4 mL (46 mmol) of triethylamine and cooling to 0° C., 3.9 mL (23 mmol) of trifluoromethanesulfonic anhydride was slowly added dropwise. After stirring for 1 hour, 1N hydrochloric acid was added, the reaction solution was extracted with methylene chloride, the organic layer was dried over anhydrous magnesium sulfate, the reaction mixture was collected by filtration, and the solvent was distilled off using a rotary evaporator. The obtained reaction mixture was purified by silica gel chromatography using a mixed solvent of hexane:methylene chloride 3:7 as a mobile phase, and 7.59 parts (18.9 mmol, yield 98%) of the compound represented by the following formula 3 was obtained as a white solid.

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 3 obtained in step 3 were as follows.
mp 73.2-74.6℃
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 7.95 (d, 1H, J = 1.5 Hz), 7.68 (s, 1H), 7.65 (d, 1H, J = 9.0 Hz), 7.55 (dd, 1H, J = 8.5, 2.0 Hz), 7.53 (s, 1H), 2.59 (s, 3H).
HRMS ₍ EI) m/ _z : Calcd for _{C12H8BrF3O3S2} [M _] ⁺ : 399.9050. _Found : 399.9065.
Elemental analysis: Calcd for _{C12H8BrF3O3S2} : C, _35.92 ; H _{, 2.01} . Found: _C , 35.76; H, 2.09.

(Step 4) Synthesis of a compound represented by the following formula 4 In a 2 L four-necked flask, 22.47 parts (56.00 mmol) of the compound represented by the formula 3 obtained in step 3 was dissolved in 1000 mL of methylene chloride. rice field. After cooling to 0° C., 13.10 parts of a 20 mass % aqueous solution of meta-chloroperbenzoic acid (mCPBA) (number of moles of meta-chloroperbenzoic acid in aqueous solution: 60.70 mmol) was slowly added. After stirring for 6 hours, the mixture was quenched with a saturated aqueous sodium hydrogencarbonate solution, the organic layer was dried over anhydrous magnesium sulfate, the reaction mixture was collected by filtration, and the solvent was distilled off using a rotary evaporator. The resulting reaction mixture was purified by silica gel chromatography using a mixed solvent of methylene chloride: ethyl acetate = 19:1 as a mobile phase, and 22.81 parts (54.67 mmol, 98%) of the compound represented by the following formula 4 was obtained. was obtained as a white solid.

The results of melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis of the compound represented by formula 4 obtained in step 4 were as follows.
mp 122.0-122.4℃
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.42 (s, 1H), 8.19 (d, 1H, J = 1.5 Hz), 7.83 (s, 1H), 7.81 (d, 1H, J = 9.0 Hz), 7.76 (dd, 1H, J = 8.5Hz, 2.0Hz), 2.90 (s, 3H).
HRMS (EI) m/ _z : _Calcd for _{C12H8BrF3O4S2} [M _] ⁺ : 415.9000. _Found : 415.9023.
Elemental analysis: Calcd for _{C12H8BrF3O4S2} : C, _34.55 ; _H , 1.93. _Found : _C , 34.40; H, 1.98.

(Step 5) Synthesis of the compound represented by the following formula 5 In a 500 mL four-necked flask, 4.17 parts (10.0 mmol) of the compound represented by the formula 4 obtained in step 4, 2-trimethylstannyl ( Naphtho[2,3-b]thiophene) 3.61 parts (10.4 mmol), lithium chloride 1.27 parts (30.0 mmol) and Pd(PPh ₃ ) ₄ 0.14 parts (0.20 mmol) were added to 1, It was dissolved in 125 mL of 4-dioxane. The mixed solution obtained above was stirred at 50° C. for 48 hours, then quenched with water, the reaction solution was extracted with methylene chloride, the organic layer was dried over anhydrous magnesium sulfate, and the reaction mixture was collected by filtration and rotary The solvent was distilled off with an evaporator. The obtained reaction mixture was purified by recrystallization to obtain 4.27 parts (94.5 mmol, yield 95%) of the compound represented by the following formula 5 as a yellow solid.

The results of melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis of the compound represented by formula 5 obtained in step 5 were as follows.
mp 262.9-264.9℃
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.56 (s, 1H), 8.37 (s, 1H), 8.36 (s, 1H), 8.20 (d, 1H, J = 1.5 Hz), 8.06 ( s, 1H), 8.01-7.99 (m, 1H), 7.95-7.93 (m, 1H), 7.82 (d, 1H, J = 8.5 Hz), 7.71 (dd, 1H, J = 8.5, 1,5 Hz) , 7.61 (s, 1H), 7.55-7.49 (m, 2H), 2.55 (s, 3H)
¹³ C NMR (CDCl ₃ , 100 MHz): δ (ppm) 143.62, 139.89, 139.08, 138.18, 133.92, 132.29, 131.81, 131.42, 131.31, 130.83, 130.58, 129.62, 128.58, 128.33, 127.31, 125.97, 125.49, 124.17 , 123.95, 122.72, 122.14, 120.47, 42.14.
HRMS (EI) m/z: Calcd for _C23H15BrOS2 [M] ⁺ : 449.9748. _{Found :} 449.9753.
Elemental analysis: _Calcd for _C23H15BrOS2 : C, 61.20; H _, 3.35. Found: C, 61.19; H, 3.36.

(Step 6) Synthesis of compound represented by Formula 6 below 226 mg (0.500 mmol) of the compound represented by Formula 5 obtained in Step 5 and 10 mL of Eaton's reagent were added to a 50 mL flask. After stirring at room temperature for 4 days, it was poured into ice water and filtered to obtain a yellow solid. This yellow solid was suspended in 35 mL of pyridine and refluxed for 20 hours. The reaction solution was cooled to room temperature, poured into methanol, and filtered to obtain a yellow solid. The resulting reaction mixture was purified by silica gel chromatography using heated chloroform as a mobile phase, and further purified by sublimation to give 140 mg (0.343 mmol, yield 69%) of the compound represented by the following formula 6 as a pale yellow solid. Obtained as crystals.

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 6 obtained in step 6 were as follows.
mp>350℃
¹ H-NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.46 (s, 1H), 8.42 (s, 1H), 8.37 (s, 2H), 8.14 (s, 1H), 8.10-8.00 (br, 2H), 7.93 (d, 1H, J = 8.5 Hz), 7.62 (dd, 1H, J = 9.0 Hz, 2.0 Hz) 7.58-7.56 (br, 2H).
HRMS (EI) m/z: Calcd for _C22H11BrS2 [M] ⁺ : _417.9486 . _Found : 417.9495.
Elemental analysis: Calcd for _C22H11BrS2 : C, 63.01; H, 2.64. _Found : C, 62.90; H, 2.71 _.

(Step 7) Synthesis of the organic semiconductor compound of the present invention represented by the following formula 7 In a 30 mL four-necked flask, 6 mL of THF and 194 mg (8.0 mmol) of magnesium shavings were added to form a suspension, and 1,2- A few drops of dibromoethane were added and stirred. Subsequently, 1.02 parts (4.0 mmol) of 1-bromo-4-(2-(2-methoxyethoxy)ethoxy)butane was added and stirred at 50° C. for 12 hours. The resulting reaction was diluted with 20 mL of THF (concentration 0.09 M). 7.0 mL (0.63 mmol) of the prepared Grignard reagent was measured into a 30 mL four-necked flask, and then 104 mg (0.25 mmol) of the compound represented by formula 6 obtained in step 6 and [1,1' - 7.3 mg (0.01 mmol) of bis(diphenylphosphino)ferrocene]palladium(II) dichloride were added. The mixture was reacted under reflux for 30 hours. After the reaction solution was cooled to room temperature, 100 mL of water was added, extracted with 100 mL of chloroform, the organic layer was dried over anhydrous magnesium sulfate, magnesium sulfate was removed by filtration, and the solvent was distilled off using a rotary evaporator. The obtained residue was purified by silica gel column chromatography, followed by crystallization using chloroform and methanol, whereby 104 mg (0.202 mmol, yield 81%) of the organic semiconductor compound of the present invention represented by the following formula 7 was obtained as a yellow solid. obtained as

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 7 obtained in step 7 were as follows.
mp 348.7°C
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.41 (s, 1H), 8.35 (s, 1H), 8.33 (s, 1H), 8.31 (s, 1H), 8.04-8.01 (m, 1H ), 7.95-7.93 (m, 2H), 7.69 (d, J = 1.5 Hz, 1H), 7.54-7.51 (m, 2H), 7.38 (dd, J = 8.5, 1.5 Hz, 1H), 3.66-3.64 ( m, 4H), 3.62-3.59 (m, 2H), 3.56-3.51 (m, 4H), 3.37 (s, 3H), 2.85 (t, J = 7.5 Hz, 2H), 1.85-1.79 (m, 2H) , 1.73-1.67 (m, 2H).
¹³ C NMR (CDCl ₃ , 125 MHz): δ (ppm) 140.9, 140.8, 140.3, 133.9, 133.3, 132.5, 131.8 (two peaks seem to be overlapped) , 131.4, 131.3, 129.9, 128.3, 128.2, 127.5, 127.4 , 125.8, 125.64, 125.61, 122.4, 121.8, 120.0, 119.9, 72.0, 71.3, 70.7, 70.6, 70.2, 59.0, 36.0, 29.4, 27.7.
HRMS (FD) m/z: [M] ⁺ calcd for _C31H30O3S2 , _514.1636 ; _{found ,} 514.1637.
Elemental analysis: _Calcd for _{C31H30O3S2 :} C, 72.34; H, 5.88 _. Found: C, 72.17; H, 5.85.

Example 2 (Synthesis of the organic semiconductor compound of the present invention represented by the following formula 8)
(Step 8)
In a pressure-resistant vial, 75 mg (0.18 mmol) of the compound represented by formula 6 obtained in step 6 and 0.6 M of sodium 2-(2-(2-methoxyethoxy)ethoxy)ethane-1-oleate of 1.6 M were added. 6 mL (0.96 mmol), 8.6 mg (0.045 mmol) of copper (I) iodide, 13.3 mg (0.045 mmol) of N ¹ ,N ² -diphenethyloxalamide (DPEO) and 5 mL of THF were added, Reaction was carried out at 140° C. for 90 minutes using a wave reactor. 20 mL of water was added to the reaction solution, extracted with chloroform, and the organic layer was dried over anhydrous magnesium sulfate. After removing the solid content by celite filtration, the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography and then purified by crystallization with chloroform and hexane to obtain 70 mg (0.14 mmol, yield 77%) of the organic semiconductor compound of the present invention represented by the following formula 8. Obtained as a yellow solid.

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 8 obtained in step 8 were as follows.
mp 373.7°C
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.41 (s, 1H), 8.34 (s, 1H), 8.28 (s, 1H), 8.27 (s, 1H), 8.04-8.01 (m, 1H ), 7.96-7.94 (m, 1H), 7.92 (d, J = 8.5 Hz, 1H), 7.54-7.51 (m, 2H), 7.24 (dd, J = 8.5 Hz, 2.5 Hz, 1H), 7.21 (d , J = 2.5 Hz, 1H), 4.31 (t, J = 4.8 Hz, 2H), 3.97 (t, J = 5.0 Hz, 2H), 3.81-3.79 (m, 2H), 3.73-3.71 (m, 2H) , 3.69-3.67 (m, 2H), 3.57-3.55 (m, 2H), 3.39 (s, 3H).
¹³ C NMR (CDCl ₃ , 125 MHz): δ (ppm) 157.0, 141.6, 140.8, 134.0, 132.7, 132.55, 132.51, 131.4, 131.3, 130.7, 129.8, 128.3, 127.4, 12 7.2, 125.8, 125.6, 122.4, 120.9 , 120.1, 119.8, 119.7, 105.6, 72.0, 71.0, 70.8, 70.7, 69.8, 67.6, 59.1.
HRMS (FD) m/z: [ _M ] ⁺ calcd for _C29H26O4S2 , 502.1273; _{found ,} 502.1273.
Elemental analysis: Calcd for _C29H26O4S2 : C, 69.30; H _, 5.21. Found: _C , 68.98; H _, 5.26.

Example 3 (Synthesis of the organic semiconductor compound of the present invention represented by the following formula 9)
(Step 9)
In a 10 mL four-necked flask, 42 mg (0.10 mmol) of the compound represented by formula 6 obtained in step 6, 54 mg (0.30 mmol) of 2-(2-(2-methoxyethoxy)ethoxy-1-thiol, Tris(dibenzylideneacetone) dipalladium(0) chloroform adduct 5.2 mg (0.005 mmol), 4,5′-bis(diphenylphosphino)-9,9′-dimethylxanthene (Xantphos) 6.9 mg (0 0.012 mmol), 21 mg (0.15 mmol) of potassium carbonate, and 2 mL of p-xylene were added and stirred, argon gas was bubbled through the mixture for 2 minutes to deaerate, and the mixture was heated under reflux for 14 hours. After the reaction, 20 mL of water was added to the reaction solution, extracted with chloroform, the organic layer was dried over anhydrous magnesium sulfate, the solid content was removed by celite filtration, and the solvent was distilled off under reduced pressure.The resulting residue was columned with silica gel. Purification by chromatography and subsequent crystallization with chloroform and methanol were performed to obtain 38 mg (0.073 mmol, yield 73%) of the organic semiconductor compound of the present invention represented by the following formula 9 as a yellow solid.

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 9 obtained in step 9 were as follows.
mp>400℃
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.42 (s, 1H), 8.36 (s, 1H), 8.31 (s, 1H), 8.30 (s, 1H), 8.05-8.03 (m, 1H ), 7.96-7.92 (m, 2H), 7.86 (d, J = 2.0 Hz, 1H), 7.55-7.52 (m, 2H), 7.47 (dd, J = 8.5, 2.0 Hz, 1H), 3.77 (t, J = 7.0 Hz, 2H), 3.69-3.64 (m, 6H), 3.55-3.53 (m, 2H), 3.37 (s, 3H), 3.29 (t, J = 7.0 Hz, 2H).
¹³ C NMR (CDCl ₃ , 125 MHz): δ (ppm) 141.7, 140.8, 134.1, 133.82, 133.76, 132.3, 132.2, 131.7, 131.5, 131.3, 129.6, 128.8, 128.3, 12 7.4, 127.1, 126.0, 125.8, 125.7 , 122.5, 121.5, 120.12, 120.0, 72.0, 70.69, 70.65, 70.57, 70.0, 59.1, 32.9.
HRMS (FD) _m /z: [M] ⁺ calcd for _C29H26O3S3 , _518.1044 ; _found , 518.1044.
Elemental analysis: Calcd _{for C29H26O3S3} : C, 67.15; H, 5.05. _Found : C _, 67.01; H, 5.05.

Example 4 (Synthesis of the organic semiconductor compound of the present invention represented by the following formula 10)
(Step 10)
In a 10 mL four-necked flask, 63 mg (0.15 mmol) of the compound represented by formula 6 obtained in step 6, 2-(5-(4-(2-(2-methoxyethoxy)ethoxy)butyl)thiophene- 2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 173 mg (0.45 mmol), dipalladium(II) acetate 0.7 mg (0.003 mmol), S-Phos 2.6 mg (0.0063 mmol), 184 mg (0.8 mmol) of potassium phosphate, 4.5 mL of toluene, and 0.5 mL of water were added and stirred. The mixture was deaerated by bubbling argon gas for 5 minutes, and the mixture was reacted for 12 hours under reflux with heating. After the reaction, the solid content was separated by celite filtration, and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography and subsequently crystallized with chloroform and methanol to obtain 77 mg (0.13 mmol, yield 86%) of the organic semiconductor compound of the present invention represented by the following formula 10 as a yellow solid. obtained as

The melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis results of the compound represented by formula 10 obtained in step 10 were as follows.

mp 385.5°C
¹ H NMR (CDCl ₃ , 500 MHz): δ (ppm) 8.42 (s, 1H), 8.39 (s, 1H), 8.37 (s, 1H), 8.32 (s, 1H), 8.07 (d, J = 2.0 Hz, 1H) 8.06-8.03 (m, 1H), 8.01 (d, J = 8.5 Hz, 1H) 7.97-7.94 (m, 1H), 7.76 (dd, J = 8.5, 2.0 Hz, 1H), 7.55-7.52 (m, 2H), 7.31 (d, J = 3.5 Hz, 1H), 6.82 (d, J = 3.5 Hz, 1H), 3.68-3.66 (m, 4H), 3.63-3.61 (m, 2H), 3.57- 3.52 (m, 4H), 3.38 (s, 3H), 2.90 (t, J = 7.5 Hz, 2H), 1.85-1.79 (m, 2H), 1.75-1.70 (m, 2H).
¹³ C NMR (CDCl ₃ , 50 °C, 175 MHz): δ (ppm) 146.0, 141.9, 141.7, 141.0, 134.1, 133.9, 132.6, 132.5, 132.4, 131.9, 131.7, 131.5, 130.5 , 128.9, 128.4, 127.4 , 126.0, 125.7, 125.5, 124.3, 123.5, 122.9, 122.5, 122.4, 120.2, 120.0, 72.2, 71.2, 70.9, 70.7, 70.4, 59.0, 30.2, 29.3, 2 8.3.
HRMS (FD) _m /z: [M] ⁺ calcd for _C35H32O3S3 , _596.1514 ; _found , 596.1515.
Elemental analysis: _{Calcd for C35H32O3S3 :} C, _70.44 ; H, 5.40. Found: C _, 70.42; H, 5.45.

Comparative Example 1 (Synthesis of Comparative Compound Represented by Formula 11 below)
(Step 11)
0.49 parts (7.5 mmol) of zinc powder and 0.36 parts (8.6 mmol) of lithium chloride were added to a 50 mL Schlenk tube, dried by heating under vacuum, and then replaced with nitrogen. 132 mg (0.315 mmol) of the compound represented by formula 6 obtained in step 6, 182 mg ₍ 0.469 mmol) of (trimethylsilylethynyl)tributyltin, and _9.5 mg (0.469 mmol) of (trimethylsilylethynyl)tributyltin were placed in a pressure-resistant vial in which argon was substituted. 0082 mmol) and 19 mL of toluene were added and heated in a microwave reactor at 180° C. for 1 hour. The reaction solution was purified by silica gel chromatography using methylene chloride as a mobile phase, and further purified by sublimation to obtain 99 mg (0.228 mmol, yield 72%) of a comparative compound represented by the following formula 11 as a yellow solid. Obtained.

The results of melting point, nuclear magnetic resonance spectrum, HR-MS spectrum and elemental analysis of the compound represented by formula 11 obtained in step 11 were as follows.
m.p. > 350℃
¹H-NMR (CDCl₃, 500 MHz): δ (ppm) 8.43 (s, 1H), 8.39 (s, 1H), 8.36 (s, 1H), 8.32 (s, 1H), 8.10 (d, 1H), 8.04 (dt, 1H, J = 4.5 Hz, 2.0 Hz), 7.96 (m, 1H), 7.95 (m, 1H) 7.55-7.35 (m, 3H), 0.311 (s, 9H).
¹³C NMR (C₂D.₂Cl_Four, 120 °C, 100 MHz): δ (ppm) 141.77, 141.03, 134.52, 133.93, 133.15, 132.40, 131.82, 131.53, 131.33, 131.03, 130.77, 128.56, 128 .31, 128.10, 127.33, 126.11, 125.08, 122.50, 122.26 , 121.05, 120.24, 119.93, 105.67, 96.01, 0.04.
HRMS (EI) m/z: Calcd for C₂₇H.₂₀S.₂Si[M]⁺Found: 436.0779.
Elemental analysis: Calcd for C₂₇H.₂₀S.₂Si: C, 74.27; H, 4.62. Found: C, 74.18; H, 4.71.

(Evaluation of solubility)
About 1 mg of the organic semiconductor compound powder obtained in Examples 1 to 4 and Comparative Example 1 was weighed into a vial, and the mass was accurately measured. Chloroform was added thereto, and the volume of chloroform added until the organic semiconductor compound was completely dissolved was confirmed. The solubility (mass [g] of the organic semiconductor compound/volume [L] of added chloroform) was calculated from the mass of the organic semiconductor compound and the amount of chloroform added. In addition, ascertainment of the point of complete dissolution was performed by visual confirmation. Comparative Example 2 refers to the measurement data of the compound represented by the following formula 12 described in Patent Document 3, and Comparative Example 3 refers to the measurement data of the compound represented by the following formula 13 described in Patent Document 4. Table 1 shows the results.

The ethylene glycol group-containing compounds of the present invention obtained in Examples 1 to 4 exhibited good solubility. On the other hand, the comparative compound having a straight-chain alkyl group obtained in Comparative Example 1 and the compound having an alkynyl group in Comparative Example 2 have low solubility in solvents, and are difficult to use as organic semiconductor materials in a solution process. be.

Example 5 (Preparation of the organic electronic device (organic transistor) of the present invention)
Chloroform was added to the organic semiconductor compound represented by Formula 7 obtained in Example 1, and the mixture was heated to prepare a 3 mg/mL solution. Using this solution, an organic thin film was prepared by spin coating on an n-doped silicon wafer with a _SiO2 thermally oxidized film that had been surface-treated with octyltrimethoxysilane, and then a shadow was formed on the organic thin film obtained above. A top-contact type organic transistor was obtained by vacuum-depositing Au using a mask to form a source electrode and a drain electrode. The obtained organic transistor had a channel length of 20 μm and a channel width of 100 μm.
FIG. 1B shows the structure of a top-contact organic transistor. In the organic transistor of this example, the thermal oxide film on the n-doped silicon wafer has the function of the insulating layer 4, and the n-doped silicon wafer has the functions of the substrate 6 and the gate electrode 5 as well.

Examples 6 to 8 (Fabrication of the organic electronic device (organic transistor) of the present invention)
According to Example 5, except that the organic semiconductor compound represented by Formula 7 obtained in Example 1 was changed to the organic semiconductor compound represented by Formulas 8 to 10 represented by Examples 2 to 4. , and top-contact type organic transistors were obtained, respectively.

Comparative Example 4 (Preparation of organic electronic device (organic transistor) for comparison)
According to Example 5, except that the organic semiconductor compound represented by Formula 7 obtained in Example 1 was changed to the organic semiconductor compound represented by Formula 13 in Comparative Example 3, the top contact type for comparison An organic transistor was obtained.

(Characteristics evaluation of organic electronic devices (organic transistors))
The performance of an organic transistor depends on the amount of current that flows when a potential is applied between the source and drain electrodes while a potential is applied to the gate electrode. The mobility can be calculated by using the measurement result of the current value in the following formula (a) expressing the electrical characteristics of the carrier species generated in the organic semiconductor layer.
Id=ZμCi(Vg−Vt) ² /2L (a)
In formula (a), Id is the saturated source-drain current value, Z is the channel width, Ci is the capacitance of the insulator, Vg is the gate potential, Vt is the threshold potential, L is the channel length, and μ is determined is the mobility (cm ² /Vs) for 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 organic transistor device, and Vt can be obtained from Id and Vg. can. By substituting each value into the equation (a), the mobility at each gate potential can be calculated.

For the organic transistors obtained in Examples 5 to 8 and Comparative Example 1, the drain current change was measured when the gate voltage was swept from +20 V to -80 V under the condition that the drain voltage was -30 V. The degree and the ratio of on-current to off-current were calculated. Table 2 shows the results.

The organic semiconductor compound of the present invention has linear substituents (Examples 1 to 3) or planar aromatic substituents (Example 4) in the vicinity of the backbone, so that the orientation of the backbone is less likely to be affected. A high mobility of the order of 10 ⁻² to 10 ⁻¹ was obtained. On the other hand, the compound of Comparative Example 3, which has a substituent with large steric hindrance at the center of the mother skeleton, showed a low mobility of 10 ⁻³ order.

Since the organic semiconductor compound represented by formula (1) of the present invention has excellent solubility in a solvent, an organic thin film can be easily formed from the organic semiconductor composition containing the condensed polycyclic aromatic compound and an organic solvent. Moreover, the organic transistor having the organic thin film exhibited excellent transistor characteristics such as a hole mobility of the order of 10 ⁻¹ cm ² /Vs and an on/off ratio of 10 ³ to 10 ⁵ .

Since the organic semiconductor material for solution processing of the present invention is excellent in solubility in organic solvents, it is suitably used in the preparation of an organic semiconductor device in a printing process such as a coating method. An organic semiconductor device having such properties exhibits good semiconductor properties. Therefore, the present invention can be used in fields such as organic transistor devices, diodes, capacitors, thin film photoelectric conversion devices, dye-sensitized solar cells, and organic EL devices.

Claims (6)

Formula (1) below
(In formula (1), m is 3, n is 2 , and L is the following formulas (2) to (6)
or represents a divalent linking group in which any two of formulas (2) to (6) are bonded, and R represents an alkyl group or an aromatic group) represented by organic semiconductor compounds. 2. The organic semiconductor compound according to claim 1 , wherein R is a methyl group. An organic semiconductor material comprising the organic semiconductor compound according to claim 1 or 2 . An organic thin film comprising the organic semiconductor material according to claim 3 . An organic electronic device comprising the organic thin film according to claim 4 . 4. A method for forming an organic thin film, comprising the steps of applying an organic solvent solution of the organic semiconductor material according to claim 3 to a substrate to form an organic semiconductor solution layer, and removing the organic solvent from the organic semiconductor solution layer.

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