JP2017039662A - Organic polycyclic aromatic compound and application thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic polycyclic aromatic compound having good requirement performances such as positive hole or electron leak prevention property, positive hole or electron transportation property, heat resistance to process temperature and visible light transparency, applicable for organic electronics devices such as an organic EL element, an organic solar cell element, an organic transistor element or a photoelectric conversion element.SOLUTION: There is provided an organic polycyclic aromatic compound represented by the formula (1), where Rto Rare each independently H, a substituted/unsubstituted aryl group, a substituted/unsubstituted alkyl group, a substituted/unsubstituted cycloalkyl group, a halogen group, a hydroxy group, an alkoxy group, a mercapto group, an alkylthio group, a nitro group or the like and at least one of Rto Ris a phenyl group having an aryl group.SELECTED DRAWING: None

Description

  The present invention relates to novel organic polycyclic aromatic compounds and their application as organic electronics materials.

 In recent years, interest in organic electronics devices has increased. Its features include a flexible structure and a large area, and further enabling an inexpensive and high-speed printing method in the electronic device manufacturing process. Typical devices include organic EL (electroluminescence) elements, organic solar cell elements, organic photoelectric conversion elements, organic transistor elements, and the like. Organic EL elements are expected as a main target for next-generation display applications as flat panel displays, and are applied from mobile phone displays to TVs (TV receivers), etc., and developments aiming at further enhancement of functionality are being continued. Research and development have been made on organic solar cell elements as flexible and inexpensive energy sources, and organic transistor elements on flexible displays and inexpensive ICs (integrated circuits).

  In developing an organic electronic device, it is very important to develop a material constituting the device. For this reason, many materials have been studied in each field, but they cannot be said to have sufficient performance, and even now, materials that are useful for various devices are being actively developed. Among them, compounds having benzotrithiophene as a mother skeleton have also been developed as organic electronics materials, such as organic transistors (Patent Documents 1 and 2, Non-Patent Document 1), organic EL (Patent Documents 1 and 2), Application to thin film solar cells (Patent Literature 1, Non-Patent Literature 2), dye-sensitized solar cells (Patent Literature 3), and the like have been reported. However, even these materials cannot be said to have sufficient performance, and have not been utilized commercially. Therefore, it is important to develop higher performance organic electronic materials.

  On the other hand, in recent organic electronics, organic photoelectric conversion elements are expected to be developed into next-generation imaging elements, and reports have been made by several groups. For example, an example in which a quinacridone derivative or a quinazoline derivative is used as a photoelectric conversion element (Patent Document 4), an example in which a photoelectric conversion element using a quinacridone derivative is applied to an imaging element (Patent Document 5), and a diketopyrrolopyrrole derivative There is an example (Patent Document 6). In general, it is considered that the performance of an imaging device is improved by aiming at reduction of dark current for the purpose of high contrast and labor saving. Therefore, in order to reduce the leakage current from the photoelectric conversion part in the dark, a technique of inserting a hole block layer or an electron block layer between the photoelectric conversion part and the electrode part is taken. In order to improve the signal current, a method of inserting a hole transport layer or an electron transport layer is taken.

  A hole blocking layer, an electron blocking layer, a hole transporting layer, and an electron transporting layer are generally widely used in the field of organic electronic devices, and each of the constituent films of the device includes an electrode or a conductive film. The film is disposed at the interface of the other film, and has a function of controlling the movement and reverse movement of holes or electrons, and adjusts the balance of unnecessary hole or electron leakage and amount, Depending on the application of the device, it is selected and used in consideration of characteristics such as heat resistance, transmission wavelength, and film forming method. However, the required performance of materials especially for photoelectric conversion elements is high, and conventional block layers and transport layers have sufficient performance in terms of leakage current prevention characteristics, heat resistance to process temperature, transparency to visible light, etc. It cannot be said that it has been used commercially.

JP 2011-6388 A International Publication No. 2010/058833 JP 2011-222373 A Japanese Patent No. 4972288 Japanese Patent No. 4945146 Japanese Patent No. 5022573 Journal of Organic Chemistry, 2011, 76, p.4061-4070 Advanced Materials, 2003, 22, p.1939-1943

  An object of the present invention is to provide a novel organic polycyclic aromatic compound that can be used in an organic electronic device. More specifically, it is to provide an organic polycyclic aromatic compound represented by the following formula (1) applicable to organic electronic devices such as organic EL elements, organic solar cell elements, organic transistor elements, and photoelectric conversion elements. . In particular, materials for various organic electronics devices, including photoelectric conversion elements, have high performance requirements such as hole or electron leakage prevention characteristics, heat resistance to process temperature, and visible light transparency, and have sufficient performance. Is required to provide.

（式（１）中、Ｒ^１〜Ｒ^６はそれぞれ水素原子、置換基を有しても良いアリール基、置換基を有しても良いアルキル基、置換基を有しても良いシクロアルキル基、ハロゲン基、ヒドロキシ基、アルコキシ基、メルカプト基、アルキルチオ基、ニトロ基、置換アミノ基、アミド基、アシル基、カルボキシル基、アシルオキシ基、シアノ基、スルホ基、スルファモイル基、アルキルスルファモイル基、カルバモイル基、またはアルキルカルバモイル基を表す。但し、Ｒ^１〜Ｒ^６のうち少なくとも一つが、アリール基を有するフェニル基を表す。）
［２］前項［１］に記載の有機多環芳香族化合物からなる有機半導体材料。
［３］前項［２］に記載の有機半導体材料を含む薄膜。
［４］前項［３］に記載の薄膜からなる正孔ブロック層。
［５］前項［３］に記載の薄膜からなる電子ブロック層。
［６］前項［３］に記載の薄膜からなる正孔輸送層。
［７］前項［３］に記載の薄膜からなる電子輸送層。
［８］前項［２］に記載の有機半導体材料を含む有機エレクトロニクスデバイス。
［９］前項［３］に記載の薄膜、及び前項［４］乃至［７］に記載の層を含む有機エレクトロニクスデバイス
［１０］前項［８］又は［９］に記載の有機エレクトロニクスデバイスを含む光電変換素子。
［１１］前項［１０］記載の光電変換素子を、複数、アレイ状に配置した撮像素子。
［１２］前項［１０］に記載の光電変換素子を含む光センサー。
［１３］前項［１０］に記載の光電変換素子を含む撮像素子。 In order to solve the above-mentioned problems, the present inventor has developed a novel organic polycyclic aromatic compound, studied the possibility as an organic electronic device, and completed the present invention.
That is, the present invention is as follows.
[1] An organic polycyclic aromatic compound represented by the following general formula (1).

(In formula (1), R ^{1 to} R ⁶ are each a hydrogen atom, an aryl group that may have a substituent, an alkyl group that may have a substituent, or a cycloalkyl group that may have a substituent. Halogen group, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group, amide group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, Represents a carbamoyl group or an alkylcarbamoyl group, provided that at least one of R ^{1 to} R ⁶ represents a phenyl group having an aryl group.
[2] An organic semiconductor material comprising the organic polycyclic aromatic compound according to [1].
[3] A thin film comprising the organic semiconductor material according to [2].
[4] A hole blocking layer comprising the thin film according to [3] above.
[5] An electronic block layer comprising the thin film as described in [3] above.
[6] A hole transport layer comprising the thin film according to [3] above.
[7] An electron transport layer comprising the thin film according to [3].
[8] An organic electronic device including the organic semiconductor material according to [2].
[9] Organic electronic device including the thin film according to [3] above and the layer according to [4] to [7] above [10] Photoelectric including the organic electronic device according to [8] or [9] above Conversion element.
[11] An image sensor in which a plurality of the photoelectric conversion elements according to [10] are arranged in an array.
[12] An optical sensor including the photoelectric conversion element according to [10] above.
[13] An imaging device including the photoelectric conversion device according to [10].

  The present invention relates to a novel organic polycyclic aromatic compound. Since the compound has good semiconductor properties, a new organic electronic device, photoelectric conversion element, imaging element, and optical sensor can be obtained by using the compound. It becomes possible to provide.

It is sectional drawing which shows an example of the preferable thin-film transistor by this invention. It is sectional drawing which shows another example of the preferable thin-film transistor by this invention. It is sectional drawing which shows another example of the preferable thin-film transistor by this invention. It is sectional drawing which shows another example of the preferable thin-film transistor by this invention. It is sectional drawing which shows another example of the preferable thin-film transistor by this invention. It is sectional drawing which shows another example of the preferable thin-film transistor by this invention. It is a figure for demonstrating the manufacturing method of a thin-film transistor. It is sectional drawing of the preferable photoelectric conversion element by this invention.

上記化合物中のＲ^１〜Ｒ^６のうち少なくとも一つが、アリール基を有するフェニル基を表す。アリール基としては、フェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、ベンゾピレニル基、ビフェニル基、テルフェニル基などの芳香族炭化水素基や、ピリジル基、ピラジル基、ピリミジル基、キノリル基、イソキノリル基、ピロリル基、インドレニル基、イミダゾリル基、カルバゾリル基、フリル基、ピラニル基、ピリドニル基などの複素環基、ベンゾキノリル基、アンスラキノリル基、ベンゾチエニル基、ベンゾフリル基のような縮合系複素環基が挙げられる。これらの内、好ましいものは、フェニル基、ナフチル基、ビフェニル基、テルフェニル基、及びピリジル基である。特にフェニル基が好ましい。またＲ^１〜Ｒ^６のフェニル基が有するアリール基の数に特に制限は無く、また化合物中で異なる置換基を有することもできる。
また、Ｒ^１、Ｒ^３、Ｒ^５のうち少なくとも一つが、アリール基を有するフェニル基であることがより好ましい。 The present invention is described in detail below.
The organic polycyclic aromatic compound represented by the following general formula (1) will be described.

At least one of R ^{1 to} R ⁶ in the compound represents a phenyl group having an aryl group. As the aryl group, an aromatic hydrocarbon group such as phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, benzopyrenyl group, biphenyl group, terphenyl group, pyridyl group, pyrazyl group, pyrimidyl group, quinolyl group, Heterocyclic groups such as isoquinolyl group, pyrrolyl group, indolenyl group, imidazolyl group, carbazolyl group, furyl group, pyranyl group, pyridonyl group, condensed heterocyclic rings such as benzoquinolyl group, anthraquinolyl group, benzothienyl group, benzofuryl group Groups. Of these, a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, and a pyridyl group are preferable. A phenyl group is particularly preferable. Further particular limitation on the number of aryl groups of the phenyl group of R ¹ to R ⁶ is not, it can also have different substituents in compounds.
More preferably, at least one of R ¹ , R ³ and R ⁵ is a phenyl group having an aryl group.

As the substituent that at least one phenyl group of R ^{1 to} R ⁶ in the formula may have in addition to the aryl group, an alkyl group, a cycloalkyl group, a halogen group, a hydroxy group, an alkoxy group, a mercapto group, Examples thereof include an alkylthio group, a nitro group, a substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group. Alkyl groups include methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, tertiary butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl Group, dodecyl group and the like. Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the halogen group include a fluoro group, a chloro group, a bromo group, and an iodo group. Examples of the alkoxy group include those in which the above alkyl group is bonded to an oxygen atom, but the number, position, and number of branches of the oxygen atom are not limited. Further particular limitation on the number of the substituent that may be possessed by the phenyl group of R ¹ to R ⁶ is not, it can also have different substituents in compounds.

When R ^{1 to} R ⁶ in the formula are not phenyl groups having an aryl group, examples of other R ^{1 to} R ⁶ may include a hydrogen atom and a substituent. Good aryl group, optionally substituted alkyl group, optionally substituted cycloalkyl group, halogen group, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group Amide group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, carbamoyl group, or alkylcarbamoyl group.

The organic polycyclic aromatic compound represented by the formula (1) can be obtained, for example, by the following reaction step. Suzuki-Miyaura coupling reaction of intermediate compound represented by formula (2) and boronic acid compound (Miyaura, Norio; Yamada, Kinji; Suzuki, Akira, Tetrahedron Letters. 1979, vol. 20, issue. 36, p. 3437 -3440), an organic polycyclic aromatic compound represented by the general formula (3) can be obtained. Alternatively, the following formula (4) used in Non-Patent Document 1 and Organic Letters 2004, vol.6, pp. 273-276 (wherein R ⁷ represents an alkyl group such as an n-butyl group). Stille coupling reaction (Milstein, D; Stille, JK) of a tin intermediate compound represented by formula (II) and an organic halide represented by RX (wherein X represents a chlorine atom, a bromine atom, or an iodine atom) , J. Am. Chem. Soc., 1978, 100, 3636-3638), the organic polycyclic aromatic compound represented by the general formula (3) can also be obtained in the same manner.

The general formula (3) (R ¹ , R ³ , R ⁵ are R, R ² , R ⁴ , R ⁶ are hydrogen atoms, and R is defined as R ^{1 to} R ⁶ in the general formula (1). The method for purifying the organic polycyclic aromatic compound represented by the formula (1) including the above is not particularly limited, and known methods such as recrystallization, column chromatography, and vacuum sublimation purification are employed. it can. Moreover, you may use combining these methods as needed.

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

  The thin film of the present invention is produced using a material containing an organic polycyclic aromatic compound represented by the above formula (1) (hereinafter referred to as “organic semiconductor material”). The thickness of the thin film varies depending on the application, but is usually 0.01 nm to 10 μm, preferably 0.05 nm to 3 μm, and more preferably 0.1 nm to 1 μm.

  Thin film formation methods are generally vacuum processes such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular layer deposition and other gas phase methods, spin coating, drop casting, dip coating, spraying and other solution methods, flexographic printing. , Letterpress printing methods such as resin letterpress printing, offset printing, dry offset printing, lithographic printing methods such as pad printing, intaglio printing methods such as gravure printing, stencil printing methods such as silk screen printing, photocopier printing and lithographic printing, inkjet Examples thereof include printing, microcontact printing, and a combination of these techniques.

  Among these, a resistance heating vapor deposition method that is a vacuum process, a spin coating method that is a solution process, a dip coating method, an ink jet method, screen printing, letterpress printing, and the like are preferable.

  The organic electronic device of the present invention can be produced using the organic polycyclic aromatic compound represented by the general formula (1) as a material for electronics (hereinafter referred to as “organic semiconductor material”). Examples of the organic electronic device include a thin film transistor, a photoelectric conversion element, an organic solar cell element, an organic EL element, an organic light emitting transistor element, and an organic semiconductor laser element. These will be described in detail.

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

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

  Hereinafter, some examples of organic thin film transistors (elements) will be described with reference to FIGS. 1A to 1F. 1A to 1F, 1 represents a source electrode, 2 represents a semiconductor layer, 3 represents a drain electrode, 4 represents an insulator layer, 5 represents a gate electrode, and 6 represents a substrate. In addition, arrangement | positioning of each layer and an electrode can be suitably selected according to the use of an element. 1A to 1D and FIG. 1F are called lateral transistors because electrodes flow in a direction parallel to the substrate. 1A is called a bottom contact bottom gate structure, and FIG. 1B is called a top contact bottom gate structure. In FIG. 1C, 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. FIG. 1D shows a structure called a top & bottom contact transistor. FIG. 1F shows a bottom contact top gate structure. FIG. 1E is a schematic diagram of a transistor having a vertical structure, that is, a static induction transistor (SIT). In this SIT, the current flow spreads out in a plane, so that a large amount of carriers can move at one time. Further, since the source electrode and the drain electrode are arranged vertically, the distance between the electrodes can be reduced, so that the response is fast. Therefore, it can be preferably applied to uses such as flowing a large current or performing high-speed switching. Although a substrate is not shown in FIG. 1E, in the normal case, a substrate is provided outside the source electrode represented by 1 or the drain electrode represented by 3 in FIG. 1E.

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, resin films, paper, glass, quartz, ceramics, etc .; products in which an insulating layer is formed on a conductive substrate such as metal or alloy by coating, etc .; from various combinations such as resin and inorganic materials Can be used. Examples of the resin film that can be used include films of resins such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyamide, polyimide, polycarbonate, cellulose triacetate, and polyetherimide. When a resin film or paper is used, the element can have flexibility, is flexible and lightweight, and improves practicality. The thickness of the substrate 6 is usually 1 μm to 10 mm, preferably 5 μm to 5 mm.

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

  In addition, a conductive composite material in which carbon black, metal particles, or the like is dispersed in the above dopant is also used. For the source electrode 1 and the drain electrode 3 that are in direct contact with the semiconductor layer 4, it is important to select an appropriate work function or to treat the surface in order to reduce the contact resistance.

  The distance (channel length) between the source electrode 1 and the drain electrode 3 is an important factor that determines the characteristics of the element. The channel length is usually 0.1 to 300 μm, preferably 0.5 to 100 μm. If the channel length is short, the amount of current that can be extracted increases, but conversely, short channel effects such as the influence of contact resistance occur and control becomes difficult, so an appropriate channel length is required. The width (channel width) between the source electrode 1 and the drain electrode 3 is usually 10 to 10000 μm, preferably 100 to 5000 μm. Further, this channel width can be made longer by making the structure of the source electrode 1 and the drain electrode 3 into a comb structure, etc., and an appropriate channel width can be obtained depending on the required amount of current and the structure of the element. Need to be length.

The structures (shapes) of the source electrode 1 and the drain electrode 3 will be described. The structure of the source electrode 1 and the structure of the drain electrode 3 may be the same or different.
In the case of the bottom contact structure, it is generally preferable to form the electrodes 1, 3, and 5 by using a lithography method, and to form the electrodes 1, 3, and 5 in a rectangular parallelepiped. In the case of a top contact structure having the electrodes 1, 3, and 5 on the semiconductor layer 2, it can be deposited using a shadow mask or the like, and an electrode pattern can also be directly printed and formed using a technique such as inkjet. The length of the electrodes 1 and 3 may be the same as the channel width. The widths of the electrodes 1, 3 and 5 are not particularly limited, but are preferably shorter in order to reduce the area of the element within a range where the electrical characteristics can be stabilized. The widths of the electrodes 1, 3, and 5 are usually 0.1 to 1000 μm, preferably 0.5 to 100 μm. The thickness of the electrodes 1, 3, and 5 is 0.1-1000 nm normally, Preferably it is 1-500 nm, More preferably, it is 5-200 nm. A wiring is connected to each of the electrodes 1, 3, and 5, but the wiring is also made of substantially the same material as the electrodes 1, 3, and 5.

An insulating material is used for the insulator layer 4. Examples of the insulating material include polyparaxylylene, polyacrylate, polymethyl methacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, and phenol. Polymers such as resins and copolymers combining them; Metal oxides such as silicon dioxide, aluminum oxide, titanium oxide, and tantalum oxide; Ferroelectric metal oxides such as SrTiO ₃ and BaTiO ₃ ; Silicon nitride, aluminum nitride, etc. Nitride; a dielectric such as sulfide or fluoride; or a polymer in which particles of the dielectric are dispersed; The film thickness of the insulator layer 4 varies depending on the material, but is usually 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, more preferably 1 nm to 10 μm.

  As the material of the semiconductor layer 2, at least one compound of the organic polycyclic aromatic compound represented by the general formula (1) of the present invention can be used as the organic semiconductor material. When a thin film is formed using the organic polycyclic aromatic compound represented by the general formula (1) and a composition containing the compound, and a solvent is used for the film formation, the solvent is positively evaporated. It is preferable to use for. As will be described later, when the semiconductor layer 2 is formed by a vapor deposition method, it is particularly preferable to use a single compound as the organic semiconductor rather than a mixture of a plurality of organic polycyclic aromatic compounds represented by the general formula (1). preferable. However, additives such as dopants for the purpose of improving the characteristics of the transistor as described above are not prevented from being contained. The case where the semiconductor layer 2 is formed by a solution process is not limited to this.

  The above additives are usually added in the range of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight, when the total amount of the organic semiconductor material is 1. It is good to do.

  The semiconductor layer 2 may be formed with a plurality of layers, but more preferably has a single layer structure. The thickness of the semiconductor layer 2 is preferably as thin as possible without losing necessary functions. In the lateral thin film transistor as shown in FIGS. 1A, 1B, and 1D, if the semiconductor layer 2 has a film thickness greater than a predetermined value, the characteristics of the element do not depend on the film thickness, while the semiconductor layer 2 has a large film thickness. This is because the leakage current often increases. The film thickness of the semiconductor layer 2 for exhibiting a necessary function is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.

  In the thin film transistor, for example, another layer can be provided between the substrate 6 and the insulator layer 4, between the insulator layer 4 and the semiconductor layer 2, or on the outer surface of the element as necessary. For example, when a protective layer is formed directly on the semiconductor layer 2 or via another layer, the influence of outside air such as humidity can be reduced, and the ON / OFF ratio of the element can be increased. There is also an advantage that the electrical characteristics can be stabilized.

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

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

  Examples of the substrate treatment for improving the characteristics as described above include hydrophobizing treatment with hexamethyldisilazane, octyltrichlorosilane, octadecyltrichlorosilane, etc .; acid treatment with hydrochloric acid, sulfuric acid, acetic acid, etc .; sodium hydroxide, water Alkaline treatment with potassium oxide, calcium hydroxide, ammonia, etc .; Ozone treatment; Fluorination treatment; Plasma treatment with oxygen, argon, etc .; Langmuir / Blodgett film formation process; Other insulator and semiconductor thin film formation process; Machine Electric treatment such as corona discharge; rubbing treatment using fibers or the like; and combinations thereof. In these embodiments, for example, a vacuum deposition method, a sputtering method, a coating method, a printing method, a sol-gel method, etc. are appropriately employed as a method of providing each layer such as a substrate layer and an insulating film layer, or an insulating film layer and an organic semiconductor layer. it can.

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

(About the thin film transistor substrate 6 and substrate processing)
The thin film transistor of the present invention is manufactured by providing various layers and electrodes necessary on the substrate 6 (see FIG. 2A). As the substrate 6, those described above can be used. It is also possible to perform the above-described surface treatment on the substrate 6. The thickness of the substrate 6 is preferably thin as long as necessary functions are not hindered. Although the thickness of the board | substrate 6 changes also with materials, it is 1 micrometer-10 mm normally, Preferably it is 5 micrometers-5 mm. Further, if necessary, the substrate 6 may have an electrode function.

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

(About formation of the insulator layer 4)
An insulator layer 4 is formed over the gate electrode 5 (see FIG. 2 (3)). As the insulator material, those described above are used. Various methods can be used to form the insulator layer 4. For example, spin coating, spray coating, dip coating, casting, bar coating, blade coating and other coating methods, screen printing, offset printing, inkjet printing methods, vacuum deposition, molecular beam epitaxial growth, ion cluster beam method, ion plating Examples thereof include dry process methods such as a coating method, a sputtering method, an atmospheric pressure plasma method, and a CVD method. In addition, a sol-gel method, alumite on aluminum, a method of forming an oxide film on a metal such as silicon dioxide on silicon, and the like are employed. In the portion where the insulator layer 4 and the semiconductor layer 2 are in contact with each other, the molecules constituting the semiconductor at the interface between the two layers, for example, the molecules of the organic polycyclic aromatic compound represented by the above formula (1) are well oriented. Therefore, a predetermined surface treatment can be performed on the insulator layer 4. As the surface treatment method, the same surface treatment as that of the substrate 6 can be used. The thickness of the insulator layer 4 is preferably as thin as possible without impairing its function. Usually, it is 0.1 nm-100 micrometers, Preferably it is 0.5 nm-50 micrometers, More preferably, it is 5 nm-10 micrometers.

(Formation of organic semiconductor layer)
The organic polycyclic aromatic compound represented by the general formula (1) of the present invention can be used as an organic semiconductor material, and can be used for forming the semiconductor layer 2 which is an organic semiconductor layer (see FIG. 2 (4)). ). Various methods can be used for forming the semiconductor layer 2. Specifically, forming methods in vacuum processes such as sputtering, CVD, molecular beam epitaxial growth, and vacuum deposition; coating methods such as dip coating, die coater, roll coater, bar coater, and spin coat , Forming methods by solution process such as inkjet method, screen printing method, offset printing method, microcontact printing method, and the like.

  When the organic polycyclic aromatic compound represented by the general formula (1) of the present invention is used as an organic semiconductor material and the semiconductor layer 2 is formed, the film is formed by a solution process such as printing or a vacuum process. And the method of forming the semiconductor layer 2 is mentioned.

First, a method for obtaining a semiconductor layer 2 by forming an organic semiconductor material by a vacuum process will be described. As a film forming method by a vacuum process, the organic semiconductor material is heated in a crucible or a metal boat under vacuum, and the evaporated organic semiconductor material is used as a substrate (substrate 6, insulator layer 4, source electrode 1 and drain electrode). 3) and the like, that is, a vacuum deposition method is preferably employed. Under the present circumstances, a vacuum degree is 1.0 * 10 < ^-1 > Pa or less normally, Preferably it is 1.0 * 10 < ^-3 > Pa or less. In addition, since the characteristics of the semiconductor layer 2 and thus the characteristics of the thin film transistor may change depending on the substrate temperature during vapor deposition, it is preferable to select the substrate temperature carefully. The substrate temperature at the time of vapor deposition is usually 0 to 200 ° C, preferably 5 to 150 ° C, more preferably 10 to 120 ° C, still more preferably 15 to 100 ° C, and particularly preferably 20 to 80 ° C. ° C.

  Moreover, a vapor deposition rate is 0.001-10 nm / sec normally, Preferably it is 0.01-1 nm / sec. The film thickness of the semiconductor layer 2 formed from an organic semiconductor material is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.

  Note that other methods may be used instead of the vapor deposition method in which the organic semiconductor material for forming the semiconductor layer 2 is heated and evaporated to adhere to the substrate.

  Next, a method for obtaining the semiconductor layer 2 by forming a film by a solution process will be described. A composition in which the organic polycyclic aromatic compound represented by the general formula (1) of the present invention is dissolved in a solvent or the like, and an additive or the like is added if necessary is used as a substrate (insulator layer 4, source electrode). 1 and the exposed portion of the drain electrode 3). Coating methods include casting, spin coating, dip coating, blade coating, wire bar coating, spray coating, and other coating methods, inkjet printing, screen printing, offset printing, letterpress printing, and other micro contact printing methods. And a method of combining a plurality of these techniques.

  Furthermore, as a method similar to the coating method, a Langmuir project method in which a monomolecular film of an organic semiconductor material produced by dropping the above-described ink on a water surface is transferred to a substrate and laminated, and two materials in a liquid crystal or melt state are used. A method of sandwiching between substrates and introducing them between the substrates by capillary action can also be adopted.

  The environment such as the temperature of the substrate and the composition at the time of film formation is also important, and the characteristics of the transistor may change depending on the temperature of the substrate and the composition. Therefore, it is preferable to carefully select the temperatures of the substrate and the composition. The substrate temperature is usually from 0 to 200 ° C, preferably from 10 to 120 ° C, more preferably from 15 to 100 ° C. Care must be taken because it greatly depends on the solvent in the composition to be used.

  The film thickness of the semiconductor layer 2 manufactured by this method is preferably as thin as possible without impairing the function. There is a concern that the leakage current increases as the film thickness increases. The film thickness of the semiconductor layer 2 is usually 1 nm to 10 μm, preferably 5 nm to 5 μm, more preferably 10 nm to 3 μm.

  The semiconductor layer 2 thus formed (see FIG. 2 (4)) can be further improved in characteristics by post-processing. For example, it is considered that the distortion in the film (semiconductor layer 2) generated at the time of film formation is reduced by heat treatment, pinholes and the like are reduced, and the arrangement and orientation in the film can be controlled. For this reason, the organic semiconductor characteristics can be improved and stabilized. When the thin film transistor of the present invention is produced, this heat treatment is effective for improving the characteristics. This heat treatment is performed by heating the substrate after forming the semiconductor layer 2. The temperature of the heat treatment is not particularly limited, but is usually from room temperature to 150 ° C, preferably 40 to 120 ° C, more preferably 45 to 100 ° C. Although there is no restriction | limiting in particular about the heat processing time at this time, Usually, it is 10 to 24 hours, Preferably it is about 30 second-3 hours. The atmosphere at that time may be air, but may be an inert atmosphere such as nitrogen or argon.

  Further, as another post-treatment method of the semiconductor layer 2, a change in characteristics due to oxidation or reduction is induced by treatment with an oxidizing or reducing gas such as oxygen or hydrogen or an oxidizing or reducing liquid. You can also This is often used for the purpose of increasing or decreasing the carrier density in the film, for example.

In addition, the characteristics of the semiconductor layer 2 can be changed by adding a trace amount of elements, atomic groups, molecules, and polymers to the semiconductor layer 2 in a technique called doping. For example, the semiconductor layer 2 is doped with an acid such as oxygen, hydrogen, hydrochloric acid, sulfuric acid, or sulfonic acid; a Lewis acid such as PF ₅ , AsF ₅ , or FeCl ₃ ; a halogen atom such as iodine; a metal atom such as sodium or potassium; can do. This can be achieved by bringing these gases into contact with the semiconductor layer 2, immersing them in a solution, or performing an electrochemical doping process. These dopings may be added at the time of synthesizing the organic semiconductor compound even after the semiconductor layer 2 is not manufactured, or may be added to the ink in the process of manufacturing the semiconductor layer 2 using the ink for manufacturing the organic semiconductor element. The thin film (semiconductor layer 2) can be added in a process step or the like. Further, a material used for doping is added to the material for forming the semiconductor layer 2 at the time of vapor deposition, and co-evaporation is performed, or the material is mixed in an ambient atmosphere when the semiconductor layer 2 is manufactured (in an environment where the doping material is present). The semiconductor layer 2 is produced), and further, ions can be accelerated in a vacuum and collide with the film for doping.

  These doping effects include changes in electrical conductivity due to increase or decrease in carrier density, changes in carrier polarity (P-type and N-type), changes in Fermi level, and the like.

(About protective layer 7)
Forming the protective layer 7 on the semiconductor layer 2 has an advantage that the influence of outside air can be minimized and the electrical characteristics of the organic thin film transistor can be stabilized (see FIG. 2 (6)). As the material for the protective layer 7, those described above are used. Although the film thickness of the protective layer 7 can employ | adopt arbitrary film thickness according to the objective, it is 100 nm-1 micrometer normally.

  Various methods can be employed to form the protective layer. When the protective layer is made of a resin, for example, a method of applying a resin solution and then drying to form a resin film; applying a resin monomer or vapor deposition And then polymerizing. Cross-linking treatment may be performed after film formation. When the protective layer is made of an inorganic material, for example, a formation method in a vacuum process such as a sputtering method or a vapor deposition method, or a formation method in a solution process such as a sol-gel method can be used.

  In the thin film transistor, a protective layer can be provided between the layers in addition to the organic semiconductor layer as necessary. These layers may help stabilize the electrical characteristics of the thin film transistor.

  Since the organic polycyclic aromatic compound represented by the general formula (1) is used as an organic semiconductor material, it can be manufactured in a relatively low temperature process. Therefore, flexible materials such as plastic plates and plastic films that could not be used under conditions exposed to high temperatures can also be used as the substrate. As a result, it is possible to manufacture a light, flexible, and hard-to-break element, which can be used as a switching element for an active matrix of a display.

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

Next, the organic EL element will be described.
Organic EL elements are attracting attention and can be used for applications such as solid, self-luminous large-area color display and illumination, and many developments have been made. The structure has a structure having two layers of a light emitting layer and a charge transport layer between a counter electrode composed of a cathode and an anode; an electron transport layer, a light emitting layer and a hole transport layer stacked between the counter electrodes. Known are those having a structure having three layers; and those having three or more layers; and those having a single light-emitting layer.

  Here, the hole transport layer has a function of injecting holes from the anode, transporting holes to the light emitting layer, facilitating injection of holes into the light emitting layer, and a function of blocking electrons. The electron transport layer has a function of injecting electrons from the cathode, transporting electrons to the light emitting layer, facilitating injection of electrons into the light emitting layer, and blocking holes. Further, in the light emitting layer, excitons are generated by recombination of the injected electrons and holes, and the energy emitted in the process of radiative deactivation of the excitons is detected as light emission. The preferable aspect of an organic EL element is described below.

  An organic EL element is an element in which one or more organic thin films are formed between an anode and a cathode, and emits light by electric energy.

  The anode that can be used in the organic EL element is an electrode having a function of injecting holes into the hole injection layer, the hole transport layer, and the light emitting layer. In general, metal oxides, metals, alloys, conductive materials, and the like having a work function of 4.5 eV or more are suitable. Specifically, although not particularly limited, conductive metal oxides such as tin oxide (NESA), indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), gold, silver, platinum, chromium And metals such as aluminum, iron, cobalt, nickel and tungsten, inorganic conductive materials such as copper iodide and copper sulfide, conductive polymers such as polythiophene, polypyrrole and polyaniline, and carbon. Among these, it is preferable to use ITO or NESA.

  If necessary, the anode may be made of a plurality of materials or may be composed of two or more layers. The resistance of the anode is not limited as long as it can supply a current sufficient for light emission of the element, but it is preferably low resistance from the viewpoint of power consumption of the element. For example, an ITO substrate having a sheet resistance value of 300Ω / □ or less functions as an element electrode, but since it is possible to supply a substrate of several Ω / □, it is desirable to use a low-resistance product. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually 5 to 500 nm, preferably 10 to 300 nm. Examples of film forming methods such as ITO include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method.

  The cathode that can be used in the organic EL element is an electrode having a function of injecting electrons into the electron injection layer, the electron transport layer, and the light emitting layer. In general, a metal or an alloy having a small work function (approximately 4 eV or less) is suitable. Specific examples include platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, calcium, and magnesium, but increase the electron injection efficiency to improve device characteristics. For this purpose, lithium, sodium, potassium, calcium and magnesium are preferred. As the alloy, an alloy with a metal such as aluminum or silver containing these low work function metals, or an electrode having a structure in which these are laminated can be used. An inorganic salt such as lithium fluoride can be used for the electrode having a laminated structure. Moreover, when light emission is taken out not to the anode side but to the cathode side, a transparent electrode that can be formed at a low temperature may be used. Examples of the film forming method include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method, but are not particularly limited. The resistance of the cathode is not limited as long as it can supply a current sufficient for light emission of the element, but it is preferably low resistance from the viewpoint of power consumption of the element, and preferably about several hundred to several Ω / □. The film thickness is usually 5 to 500 nm, preferably 10 to 300 nm.

Furthermore, for sealing and protection, oxides such as titanium oxide, silicon nitride, silicon oxide, silicon nitride oxide, germanium oxide, nitrides, or mixtures thereof, polyvinyl alcohol, vinyl chloride, hydrocarbon polymers, fluorine The cathode can be protected with a polymer, etc., and sealed with a dehydrating agent such as barium oxide, phosphorus pentoxide, or calcium oxide.

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

  The organic thin film of the organic EL element is formed of one layer or a plurality of layers between the anode and cathode electrodes. By containing the organic polycyclic aromatic compound represented by the general formula (1) in the organic thin film, an element that emits light by electric energy can be obtained.

  One or more “layers” forming an organic thin film are a hole transport layer, an electron transport layer, a hole transport light-emitting layer, an electron transport light-emitting layer, and a hole blocking layer (hole block layer). , An electron blocking layer (electron blocking layer), a hole injection layer, an electron injection layer, a light emitting layer, or a single layer having the functions of these layers as shown in Structural Example 9) below. Examples of the configuration of the layer forming the organic thin film in the present invention include the following configuration examples 1) to 9), and any configuration may be used.

Configuration Example 1) Hole transport layer / electron transport light emitting layer.
2) Hole transport layer / light emitting layer / electron transport layer.
3) Hole transporting light emitting layer / electron transporting layer.
4) Hole transport layer / light emitting layer / hole blocking layer.
5) Hole transport layer / light emitting layer / hole blocking layer / electron transport layer.
6) Hole transporting light emitting layer / hole blocking layer / electron transporting layer.
7) In each of the combinations 1) to 6), a hole injection layer is further provided in front of the hole transport layer or the hole transport light emitting layer.
8) A structure in which an electron injecting layer is further provided in front of the electron transporting layer or the electron transporting light emitting layer in each of the combinations 1) to 7).
9) A configuration in which materials used in the combinations 1) to 8) are mixed, and only one layer containing the mixed materials is included.
In the above 9), a single layer formed of a material generally called a bipolar luminescent material; or only one layer including a luminescent material and a hole transport material or an electron transport material may be provided. In general, with a multilayer structure, charges, that is, holes and / or electrons can be efficiently transported and these charges can be recombined. In addition, by suppressing the quenching of charges, the stability of the element can be prevented from being lowered and the light emission efficiency can be improved.

  The hole injection layer and the hole transport layer are formed by laminating a hole transport material alone or a mixture of two or more kinds of the materials. As a hole transport material, N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4 ″ -diphenyl-1,1′-diamine, N, N′-dinaphthyl-N , N′-diphenyl-4,4′-diphenyl-1,1′-diamine and the like, bis (N-allylcarbazole) or bis (N-alkylcarbazole) s, pyrazoline derivatives, stilbene compounds, In the case of a hydrazone compound, a triazole derivative, a heterocyclic compound typified by an oxadiazole derivative or a porphyrin derivative, or a polymer system, a polycarbonate, a styrene derivative, polyvinyl carbazole, polysilane, or the like having the monomer in the side chain can be preferably used. There is no particular limitation as long as a thin film necessary for device fabrication is formed, holes can be injected from the electrodes, and holes can be transported. As a hole injection layer provided between the hole transport layer and the anode for improving the hole injection property, a phthalocyanine derivative, m-MTDATA (4,4 ′, 4 ″ -tris [phenyl (m-tolyl) ) Amino] triphenylamine) and the like, and in a polymer system, those made of polythiophene such as PEDOT (poly (3,4-ethylenedioxythiophene)), polyvinylcarbazole derivatives, and the like.

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

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

  The light emitting layer means an organic thin film that emits light, and can be said to be, for example, a hole transporting layer, an electron transporting layer, or a bipolar transporting layer having strong light emitting properties. The light emitting layer only needs to be formed of a light emitting material (host material, dopant material, etc.), which may be a mixture of a host material and a dopant material or a host material alone. Each of the host material and the dopant material may be one kind or a combination of a plurality of materials.

  The dopant material may be included in the host material as a whole, or may be included partially. The dopant material may be either laminated or dispersed. Examples of the light emitting layer include the above-described hole transport layer and electron transport layer. Materials used for the light-emitting layer include carbazole derivatives, anthracene derivatives, naphthalene derivatives, phenanthrene derivatives, phenylbutadiene derivatives, styryl derivatives, pyrene derivatives, perylene derivatives, quinoline derivatives, tetracene derivatives, perylene derivatives, quinacridone derivatives, coumarin derivatives, Examples include porphyrin derivatives and phosphorescent metal complexes (Ir complex, Pt complex, Eu complex, etc.).

  The organic thin film formation method of the organic EL element is generally a resistance heating evaporation that is a vacuum process, electron beam evaporation, sputtering, molecular lamination method, casting that is a solution process, spin coating, dip coating, blade coating, wire bar. Uses coating methods such as coating and spray coating, printing methods such as inkjet printing, screen printing, offset printing and letterpress printing, soft lithography methods such as microcontact printing, and a combination of these methods. Yes. The thickness of each layer depends on the resistance value and charge mobility of each substance and cannot be limited, but is selected from 0.5 to 5000 nm. Preferably it is 1-1000 nm, More preferably, it is 5-500 nm.

  Among the organic thin films constituting the organic EL element, one or more thin films such as a light emitting layer, a hole transport layer, and an electron transport layer existing between the anode and the cathode are represented by the above general formula (1). By containing the organic polycyclic aromatic compound, an element that efficiently emits light even with low electric energy can be obtained.

  The organic polycyclic aromatic compound represented by the general formula (1) can be suitably used as a hole transport layer, a light emitting layer, an electron transport layer, a hole block layer, or an electron block layer. For example, it can be used in combination with the above-described electron transport material, hole transport material, light emitting material, or the like.

Specific examples of the dopant material when the organic polycyclic aromatic compound represented by the general formula (1) is used as a host material in combination with the dopant material include perylene derivatives such as bis (diisopropylphenyl) perylenetetracarboxylic imide. , Perinone derivatives, 4- (dicyanomethylene) -2methyl-6- (p-dimethylaminostyryl) -4H pyran (DCM) and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, oxazine compounds, squarylium compounds, violanthrone compound, Nile red, 5- Shianopirometen -BF ₄ pyrromethene derivatives complexes, further acetylacetone and benzoyl as phosphorescent material Eu complexes having acetone and phenanthroline as ligands, porphyrins such as Ir complexes, Ru complexes, Pt complexes, Os complexes, ortho metal metal complexes and the like can be used, but are not particularly limited thereto. In addition, when two kinds of dopant materials are mixed, it is also possible to obtain light emission with improved color purity by efficiently transferring energy from the host dye using an assist dopant such as rubrene. In any case, in order to obtain high luminance characteristics, it is preferable to dope those having a high fluorescence quantum yield.

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

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

  The organic EL element can be suitably used as a flat panel display. It can also be used as a flat backlight. In this case, either a light emitting colored light or a light emitting white light can be used. The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display board, a sign, and the like. In particular, liquid crystal display devices, particularly thin backlights for personal computers, which have been a problem for thinning, are difficult to thin because they are made of fluorescent lamps and light guide plates. Since the backlight using the element is thin and lightweight, the above problems are solved. Similarly, it can be usefully used for illumination.

  When the organic polycyclic aromatic compound represented by the general formula (1) of the present invention is used, an organic EL display device having high luminous efficiency and a long lifetime can be obtained. Further, by combining the thin film transistor element of the present invention, it becomes possible to supply an organic EL display device in which the applied voltage on / off phenomenon is electrically controlled with high accuracy at low cost.

Next, the organic solar cell element will be described.
A flexible and low-cost organic solar cell element can be easily produced using the organic polycyclic aromatic compound represented by the general formula (1). That is, the organic solar cell element is advantageous in terms of flexibility and improved life because it does not use an electrolyte solution unlike the dye-sensitized solar cell. Conventionally, the development of solar cells using organic thin film semiconductors combined with conductive polymers, fullerenes and the like has been mainstream, but power generation conversion efficiency is a problem.

  In general, the configuration of an organic solar cell element is similar to a silicon solar cell, in which a layer for generating power (a power generation layer) is sandwiched between an anode and a cathode, and holes and electrons generated by absorbing light are received by each electrode. It functions as a solar cell. The power generation layer is composed of a P-type material, an N-type material, and other materials such as a buffer layer. A material in which an organic material is used as the material is called an organic solar cell. Structures include Schottky junctions, heterojunctions, bulk heterojunctions, nanostructure junctions, hybrids, etc. Each material efficiently absorbs incident light and generates charges, and the generated charges (holes and electrons) It functions as a solar cell by separating, transporting and collecting.

Next, components in the organic solar cell element will be described.
The anode and cathode in the organic solar cell element are the same as those of the organic EL element described above. Since it is necessary to take in light efficiently, it is desirable to use an electrode having transparency in the absorption wavelength region of the power generation layer. Moreover, in order to have a favorable solar cell characteristic, it is preferable that sheet resistance is 20 ohms / square or less.

  The power generation layer is formed of one or more layers of an organic thin film containing at least the organic polycyclic aromatic compound represented by the general formula (1). The organic solar cell can take the structure shown above, but basically includes a P-type material, an N-type material, and a buffer layer.

  As the P-type material, a compound capable of transporting holes in the same manner as the hole injection and hole transport layer described in the section of the organic EL element, a polyparaphenylene vinylene derivative, a polythiophene derivative, a polyfluorene derivative, Examples include π-conjugated polymers such as polyaniline derivatives, carbazole and other polymers having a heterocyclic ring in the side chain. In addition, pentacene derivatives, rubrene derivatives, porphyrin derivatives, phthalocyanine derivatives, indigo derivatives, quinacridone derivatives, merocyanine derivatives, cyanine derivatives, squalium derivatives, benzoquinone derivatives, and the like can be given.

The N-type layer basically has a compound capable of transporting electrons, an oligomer or a polymer having skeleton of pyridine and its derivatives, and a quinoline and its derivatives as the electron transport layer described in the section of the organic EL element. Polymer materials such as oligomers and polymers, polymers having benzophenanthrolines and derivatives thereof, cyanopolyphenylene vinylene derivatives (CN-PPV (cyanopolyphenylene vinylene), etc.), fluorinated phthalocyanine derivatives, perylene derivatives, naphthalene derivatives, bathocuproin _derivatives, low molecular materials such as fullerene derivatives such as _{C 60} and _C 70, PCBM (phenyl _{C 61} butyric acid methyl ester), and the like. Each of them preferably absorbs light efficiently and generates a charge, and the material used has a high extinction coefficient.

  The organic polycyclic aromatic compound represented by the general formula (1) can be particularly preferably used as an N-type material. The method for forming the thin film for the power generation layer of the organic solar cell may be the same as the method described in the section of the organic EL element. Although the thickness of the thin film varies depending on the configuration of the solar cell, it is better to thicken it to absorb light sufficiently and prevent short-circuiting, but it is better to transport the generated charge because the shorter distance is better. Is suitable. In general, the thickness of the power generation layer is preferably about 10 to 5000 nm.

(About organic semiconductor laser elements)
Since the organic polycyclic aromatic compound represented by the general formula (1) is a compound having organic semiconductor characteristics, utilization as an organic semiconductor laser element is expected. That is, a resonator structure can be incorporated into the organic semiconductor element containing the organic polycyclic aromatic compound represented by the general formula (1), and carriers can be efficiently injected to sufficiently increase the density of excited states. For example, it is expected that the light is amplified and causes laser oscillation. Conventionally, only laser oscillation by optical excitation has been observed, and it is very difficult to inject high-density carriers necessary for laser oscillation by electrical excitation into an organic semiconductor element to generate a high-density excitation state. Although proposed, the use of an organic semiconductor element containing the organic polycyclic aromatic compound represented by the general formula (1) is expected to cause highly efficient light emission (electroluminescence).

(About organic light-emitting transistors)
Next, an organic light emitting transistor will be described. The organic polycyclic aromatic compound represented by the general formula (1) can also be used for an organic light-emitting transistor. A light-emitting transistor that combines an organic transistor and an organic electroluminescent element has a structure in which the drive circuit and light-emitting part of the display are integrated, reducing the area occupied by the drive transistor circuit and increasing the aperture ratio of the display unit. Can do. That is, the number of parts can be reduced and the manufacturing process is simplified, so that a display with lower cost can be obtained. In principle, light is emitted by simultaneously injecting electrons and holes from the source and drain electrodes of the organic transistor into the organic light emitting material and recombining them. The adjustment of the light emission amount is controlled by the electric field from the gate electrode.

  The structure may be the same as that described in the section of the organic transistor, and a light emitting transistor material can be used instead of the structure of the semiconductor layer for the organic transistor. The material and process to be used can be selected as appropriate depending on the characteristics of the semiconductor compound, and a configuration for extracting light to the outside is desirable. In ordinary organic transistors, only one of electrons or holes need to be injected, but in the case of light-emitting transistors, light is emitted by the combination of electrons and holes in the semiconductor layer. -A structure that promotes bonding and light emission is preferable.

(About photoelectric conversion elements)
Next, the photoelectric conversion element will be described.
The organic polycyclic aromatic compound represented by the general formula (1) can be used as a photoelectric conversion element. An organic photoelectric conversion element is an element in which a photoelectric conversion unit including a photoelectric conversion film is disposed between two opposing electrode films, which are an upper electrode and a lower electrode, and light is incident on the photoelectric conversion unit from above one electrode. It is incident. The photoelectric conversion unit generates electrons and holes according to the amount of incident light, and a signal corresponding to the charge is read out by a semiconductor to indicate the amount of incident light according to the absorption wavelength of the photoelectric conversion film unit. It is an element. In some cases, a transistor for reading is connected to the lower electrode film. When a large number of the photoelectric conversion elements are arranged on the array, in addition to the amount of incident light, the incident position information is indicated, so that the imaging element of the present invention is obtained. In addition, regarding the incidence of light, when the photoelectric conversion element including the electrode existing in the rear part is not disturbed by the photoelectric conversion element existing in the front part, even if a plurality of photoelectric conversion elements are stacked. good. Furthermore, when the above-described plurality of photoelectric conversion elements absorb different visible lights, a multicolor imaging element is formed, and a full color photodiode is obtained.

FIG. 3 shows an example of a photoelectric conversion element.
3, 11 is an insulating portion, 12 is an upper electrode, 13 is an electron blocking layer, 14 is a photoelectric conversion portion, 15 is a hole blocking layer, 16 is a lower electrode, 17 is an insulating base material, or photoelectric. Each conversion element is represented. Although the readout transistor is not shown in the drawing, it may be connected to the lower electrode, and further, it may be formed under the lower electrode if the semiconductor is transparent. The incident light may be incident from any of the upper and lower portions as long as the light other than the photoelectric conversion portion does not extremely disturb the absorption wavelength of the photoelectric conversion portion.

  Here, the photoelectric conversion part is often composed of a plurality of layers such as a photoelectric conversion layer, an electron transport layer, a hole transport layer, an electron block layer, a hole block layer, a crystallization prevention layer, an interlayer contact improvement layer, It is not limited to this.

  In general, an organic semiconductor film is used for the photoelectric conversion layer. However, the organic semiconductor film may be a single layer or a plurality of layers. In this case, a P-type organic semiconductor film, an N-type organic semiconductor film, Alternatively, a mixed film (bulk heterostructure) thereof is used. On the other hand, in the case of a plurality of layers, it is about 2-10 layers, and is a structure in which any one of a P-type organic semiconductor film, an N-type organic semiconductor film, or a mixed film (bulk heterostructure) is laminated. A buffer layer may be inserted in

  For organic semiconductor films, triarylamine compounds, benzidine compounds, pyrazoline compounds, styrylamine compounds, hydrazone compounds, triphenylmethane compounds, carbazole compounds, polysilane compounds, thiophene compounds, phthalocyanine compounds, cyanine compounds depending on the wavelength band to be absorbed , Merocyanine compound, oxonol compound, polyamine compound, indole compound, pyrrole compound, pyrazole compound, polyarylene compound, carbazole derivative, naphthalene derivative, anthracene derivative, phenanthrene derivative, phenylbutadiene derivative, styryl derivative, quinoline derivative, tetracene derivative, pyrene derivative Perylene derivatives, fluoranthene derivatives, quinacridone derivatives, coumarin derivatives, porphyrin derivatives and phosphorescent gold Complex (Ir complexes, Pt complexes, Eu complexes, etc.), or the like can be used.

  Here, the hole transport layer transports the generated holes from the photoelectric conversion layer to the electrode, facilitates movement of holes from the photoelectric conversion layer to the electrode, and functions to block electron transfer from the electrode. Have The electron transport layer has a function of transporting generated electrons from the photoelectric conversion layer to the electrode, facilitating movement of electrons from the photoelectric conversion layer to the electrode, and a function of blocking movement of holes from the electrode. . In addition, the hole blocking layer has a function of preventing movement of holes from the electrode to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current. The electron blocking layer has a function of preventing movement of electrons from the electrode to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current. In addition, the hole block layer and the electron block layer preferably have high transmittance at the absorption wavelength of the photoelectric conversion layer, or are preferably used as a thin film, in order not to prevent light absorption of the photoelectric conversion film. Furthermore, in the photoelectric conversion layer, by receiving incident light, the generated electrons and holes are transported to the electrodes, and are sent as electrical signals to the readout circuit.

  The electrode film that can be used in the organic photoelectric conversion element collects holes from a hole transport photoelectric conversion film or a hole transport film contained in the photoelectric conversion layer, or is included in the photoelectric conversion layer In order to take out electrons from the electron transport photoelectric conversion film or electron transport film and discharge the electrons, adjacent films such as a hole transport photoelectric conversion film and a hole transport film, or an electron transport photoelectric conversion film and an electron transport Since it is selected in consideration of adhesion with an adjacent film such as a film, electron affinity, ionization potential, stability, etc., it is not particularly limited. However, tin oxide (NESA), indium oxide, indium tin oxide (ITO) ), Conductive metal oxides such as zinc oxide indium (IZO), metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, tungsten, iodide , Inorganic conductive materials such as copper sulfide, polythiophene, polypyrrole, and conductive polymers or carbon such as polyaniline. If necessary, a plurality of materials may be used, or two or more layers may be used. The resistance of the electrode is not limited, but is not limited as long as it does not interfere with the light reception of the element more than necessary. From the viewpoint of signal strength of the element and power consumption, the resistance is preferably low. For example, an ITO substrate having a sheet resistance value of 300Ω / □ or less functions as an element electrode, but since it is possible to supply a substrate of several Ω / □, it is desirable to use a low-resistance product. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually 5 to 500 nm, preferably 10 to 300 nm. Examples of film forming methods such as ITO include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method. If necessary, UV-ozone treatment, plasma treatment or the like can be performed.

Particularly preferable as the material for the transparent electrode film are ITO, IZO, SnO ₂ , ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO ₂ , FTO (fluorine). Doped tin oxide). The light transmittance of the transparent electrode film is preferably 60% or more, more preferably 80% or more, more preferably 90% or more, at the absorption peak wavelength of the photoelectric conversion film included in the photoelectric conversion part including the transparent electrode film. More preferably, it is 95% or more.

  In addition, when a plurality of photoelectric conversion layers are stacked, the electrodes inside the stacked films need to transmit light having a wavelength other than the light detected by each photoelectric conversion film, and preferably 90%, more preferably, the absorbed light. It is preferable to use a material that transmits 95% or more of light.

  The electrode film is preferably made plasma-free. By forming the electrode film without plasma, the influence of plasma on the substrate can be reduced, and the photoelectric conversion characteristics can be improved. Here, plasma free means that no plasma is generated during the 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, more preferably 20 cm or more, and reaches the substrate. It means a state where the plasma to be reduced decreases.

  Examples of an apparatus that does not generate plasma during the formation of an electrode film include an electron beam vapor deposition apparatus (EB vapor deposition apparatus) and a pulse laser vapor deposition apparatus. Hereinafter, a method of forming a transparent electrode film using an EB vapor deposition apparatus is referred to as an EB vapor deposition method, and a method of forming a transparent electrode film using a pulse laser vapor deposition apparatus is referred to as a pulse laser vapor deposition method.

  As an apparatus that can realize a state in which plasma can be reduced during film formation (hereinafter referred to as a plasma-free film formation apparatus), for example, an opposed target sputtering apparatus or an arc plasma deposition method can be considered.

  When a transparent conductive film such as TCO (transparent conductive oxide) is used as an electrode film, a DC (direct current) short circuit or an increase in leakage current may occur. One reason for this is thought to be that fine cracks introduced into the photoelectric conversion film are covered with a dense film such as TCO, and conduction between the opposite electrode film is increased. For this reason, in the case of an electrode having a poor film quality such as Al, an increase in leakage current hardly occurs. By controlling the film thickness of the electrode film with respect to the film thickness (crack depth) of the photoelectric conversion film, an increase in leakage current can be largely suppressed.

  Usually, when the conductive film is made thinner than a certain range, the resistance value is rapidly increased. However, in the solid-state imaging device of this embodiment, the sheet resistance is preferably 100 to 10000Ω / □, and the film thickness can be reduced. The degree of freedom is large. Further, the thinner the transparent conductive thin film is, the less light is absorbed, and the light transmittance is generally increased. The increase in light transmittance is very preferable because it increases the light absorption in the photoelectric conversion film and increases the photoelectric conversion ability.

  The hole blocking layer is formed by laminating and mixing hole blocking substances alone or two or more kinds. As the hole blocking substance, phenanthroline derivatives such as bathophenanthroline and bathocuproin, silole derivatives, quinolinol derivative metal complexes, oxadiazole derivatives, oxazole derivatives, and the like are used. The compound is not particularly limited as long as it is a compound that can prevent flowing out of the element. The organic polycyclic aromatic compound represented by the general formula (1) can be particularly preferably used as a material for the hole blocking layer. The method for forming the hole blocking layer thin film of the organic photoelectric conversion element may be as described below. For the purpose of preventing leakage current, it is better that the film thickness is thin. However, since a sufficient amount of current is required for signal readout at the time of light incidence, the film thickness should be as thin as possible. In general, the power generation layer is preferably about 5 to 500 nm.

  Generally, the organic thin film of the organic photoelectric conversion device is formed by resistance heating vapor deposition which is a vacuum process, electron beam vapor deposition, sputtering, molecular lamination method, casting which is a solution process, spin coating, dip coating, blade coating, wire. Coating methods such as bar coating and spray coating, printing methods such as ink jet printing, screen printing, offset printing and letterpress printing, soft lithography methods such as microcontact printing, and a combination of these methods Can be adopted. The thickness of each layer depends on the resistance value and charge mobility of each substance and cannot be limited, but is selected from 0.5 to 5000 nm. Preferably it is 1-1000 nm, More preferably, it is 5-500 nm.

  Among the organic thin films constituting the organic photoelectric conversion element, one or more thin films such as a photoelectric conversion layer, a hole transport layer, a hole block layer, an electron transport layer, and an electron block layer, which are present between the electrodes, are described above. By including the organic polycyclic aromatic compound represented by the general formula (1), it is possible to obtain an element that efficiently converts even a weak light energy into an electric signal.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated still in detail, this invention is not limited to these examples. In Examples, unless otherwise specified, parts are parts by mass,% is mass%, compound No. Corresponds to the compounds described in the specific examples. Moreover, the reaction temperature described the internal temperature in a reaction system unless there is particular notice. Moreover, unless otherwise specified, the application measurement of the current voltage in an Example or a comparative example was performed using the semiconductor parameter analyzer 4200-SCS (Keithley Instruments company). Irradiation of incident light was performed using PVL-3300 (Asahi Spectroscopy Co., Ltd.) at an irradiation light wavelength of 550 nm and an irradiation light half width of 20 nm unless otherwise specified.

Example 1
2,5,8-tris (4-biphenyl) benzo [1,2-b: 3,4-b ′: 5,6-b ″] trithiophene (compound (111))
Under a nitrogen atmosphere, put 2,5,8, -tris (tributylstannyl) benzo [1,2-b: 3,4-b ′: 5,6-b ″] trithiophene (3.3 mmol) in a flask. Dimethylformamide (100 ml) was added, 116 mg (0.1 mmol) of tetrakistriphenylphosphine palladium and 4.615 g (19.8 mmol) of 4-bromobiphenyl were added, and the mixture was heated to 80 ° C. and stirred for 12 hours. The precipitated solid was separated by filtration and dried, and the obtained solid was purified by sublimation under reduced pressure, whereby 2,5,8-tris (4-biphenyl) benzo [1,2-b: 3,4-b ′: 5. , 6-b ″] trithiophene (381 mg) was obtained. 1H NMR, (400 MHz, CDCl3) δ 7.38-7.41 (m, 3H), 7.47-7.52 (m, 6H), 7.66-7.68 (m, 6H), 7.71 (d, J = 8.4 Hz, 6H), 7.86 (s, 3H), 7.89 (d, J = 8.4 Hz, 6H). EI-MS m / z = 702 (M ⁺ )

(Example 2)
2,5,8-tris (3,5-diphenylphenyl) benzo [1,2-b: 3,4-b ′: 5,6-b ″] trithiophene (compound (114))
Under a nitrogen atmosphere, put 2,5,8, -tris (tributylstannyl) benzo [1,2-b: 3,4-b ′: 5,6-b ″] trithiophene (3.0 mmol) in a flask. Dimethylformamide (80 ml) was added, 116 mg (0.1 mmol) of tetrakistriphenylphosphine palladium and 5.566 g (18 mmol) of 1-bromo-3,5-diphenylbenzene were added, and the mixture was heated to 80 ° C. and stirred for 24 hours. The precipitated solid was separated by filtration and dried, and the resulting solid was purified by sublimation under reduced pressure, whereby 2,5,8-tris (3,5-diphenylphenyl) benzo [1,2-b: 3,4-b ': 5,6-b ″] trithiophene (958 mg) was obtained. The measurement results of EI-MS of the obtained compound are shown below.
EI-MS m / z = 930 (M ⁺ )

(Example 3)
Production and Evaluation of Photoelectric Conversion Element 2,5,8-Tris (4-biphenyl) benzo [1,2-] obtained in Example 1 above was applied to ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness 150 nm). b: 3,4-b ′: 5,6-b ″] trithiophene was deposited to a thickness of 50 nm by resistance heating vacuum deposition. Next, quinacridone was formed into a 100 nm vacuum film as a photoelectric conversion layer. A 100 nm vacuum film of aluminum was formed thereon as an electrode to produce a photoelectric conversion element. When ITO and aluminum were used as electrodes and a voltage of 5 V was applied to the aluminum side, the ratio between the current in the dark and the current during light irradiation was 6.5 × 10 ² .

Example 4
Production and Evaluation of Photoelectric Conversion Element 2,5,8-Tris (3,5-diphenylphenyl) benzo [1] obtained in Example 2 above was applied to ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness 150 nm). , 2-b: 3,4-b ′: 5,6-b ″] trithiophene was deposited to a thickness of 50 nm by resistance heating vacuum deposition. Next, quinacridone was formed into a 100 nm vacuum film as a photoelectric conversion layer. A 100 nm vacuum film of aluminum was formed thereon as an electrode to produce a photoelectric conversion element. When ITO and aluminum were used as electrodes and a voltage of 5 V was applied to the aluminum side, the ratio of the current in the dark and the current during light irradiation was 8.9 × 10 ³ .

(Comparative Example 1)
Preparation of photoelectric conversion element and its evaluation Quinacridone was formed into a 100 nm vacuum film as a photoelectric conversion layer on ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness 150 nm). A 100 nm vacuum film of aluminum was formed thereon as an electrode to produce a photoelectric conversion element. When ITO and aluminum were used as electrodes and a voltage of 5 V was applied to the aluminum side, the ratio between the current in the dark and the current during light irradiation was 1.2 × 10 ² .

(Comparative Example 2)
Preparation of photoelectric conversion element and its evaluation Tris (8-quinolinolato) aluminum was formed into a film of 50 nm by resistance heating vacuum deposition on ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness of 150 nm) as a hole blocking layer. Next, quinacridone was formed into a 100 nm vacuum film as a photoelectric conversion layer. A 100 nm vacuum film of aluminum was formed thereon as an electrode to produce a photoelectric conversion element. When ITO and aluminum were used as electrodes and a voltage of 5 V was applied to the aluminum side, the ratio between the current in the dark and the current during light irradiation was 4.3 × 10.

    As is clear from the above examples, the organic polycyclic aromatic compound obtained by the present invention exhibited semiconductor characteristics and further exhibited good dark current prevention characteristics, and thus was highly versatile for organic electronic devices. It can be said that it is a useful compound having properties. In addition, the device using the organic polycyclic aromatic compound according to the present invention has a very high leakage current suppressing effect and does not inhibit the on-current at the time of light incidence. It is a power consumption type organic electronics device.

  The organic polycyclic aromatic compound of the present invention is useful as a material for an organic semiconductor. In particular, the organic polycyclic aromatic compound of the present invention is effectively used as a material for organic electronic devices. For this reason, this invention has high industrial applicability.

DESCRIPTION OF SYMBOLS 1 Source electrode 2 Semiconductor layer 3 Drain electrode 4 Insulator layer 5 Gate electrode 6 Substrate 7 Protective layer 11 Insulating part 12 Upper electrode 13 Electron block layer 14 Photoelectric conversion part 15 Hole blocking layer 16 Lower electrode 17 Insulating base material or others Photoelectric conversion element

Claims (13)

An organic polycyclic aromatic compound represented by the following general formula (1).

(In formula (1), R ^{1 to} R ⁶ are each a hydrogen atom, an aryl group that may have a substituent, an alkyl group that may have a substituent, or a cycloalkyl group that may have a substituent. Halogen group, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group, amide group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, Represents a carbamoyl group or an alkylcarbamoyl group, provided that at least one of R ^{1 to} R ⁶ represents a phenyl group having an aryl group. An organic semiconductor material comprising the organic polycyclic aromatic compound according to claim 1. A thin film comprising the organic semiconductor material according to claim 2. A hole blocking layer comprising the thin film according to claim 3. An electronic block layer comprising the thin film according to claim 3. A hole transport layer comprising the thin film according to claim 3. An electron transport layer comprising the thin film according to claim 3. An organic electronic device comprising the organic semiconductor material according to claim 2. An organic electronic device comprising the thin film according to claim 3 and the layer according to claims 4-7. The photoelectric conversion element containing the organic electronics device of Claim 8 or 9. An image sensor in which a plurality of the photoelectric conversion elements according to claim 10 are arranged in an array. An optical sensor comprising the photoelectric conversion element according to claim 10. An imaging device comprising the photoelectric conversion device according to claim 10.

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