Fused polycyclic aromatic compound, material for photoelectric converters, organic thin film, and organic photoelectric converter

Abstract

To provide an organic compound that serves as a material for organic photoelectric converters with superior response speed, and an organic thin film containing the organic compound, and an organic photoelectric converter containing the organic thin film.SOLUTION: The present invention provides a fused polycyclic aromatic compound represented by the formula (1) (where R1 represents a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, and R2 and R3 independently represent a substituted or unsubstituted aromatic hydrocarbon group).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a novel fused polycyclic aromatic compound and its use. More specifically, the present invention relates to a fused polycyclic aromatic compound that is a benzothieno[3,2-b][1]benzothiophene (hereinafter abbreviated as "BTBT") derivative, a photoelectric conversion element material and an organic thin film containing the compound, and an organic photoelectric conversion element containing the organic thin film. [Background technology]

[0002] Organic electronics devices have been actively researched and developed in recent years because they can be supplied stably as they do not contain rare metals in the raw materials, have flexibility not found in inorganic materials, and can be manufactured by wet film formation methods. Specific examples of organic electronics devices include organic EL elements, organic solar cell elements, organic photoelectric conversion elements, and organic transistor elements, and various other applications that take advantage of the characteristics of organic compounds as well as the performance of the devices are being considered.

[0003] Among the above-mentioned devices, organic photoelectric conversion elements are used in optical sensors, etc., and their use in image sensors, for example, is being considered (Patent Document 1). However, image sensors are required to have a response speed sufficient to capture moving objects (Patent Document 2).

[0004] In order to meet this demand, the use of BTBT-based compounds, which are known to exhibit high mobility as organic semiconductor materials, in photoelectric conversion elements has been investigated (Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2022 / 114065 [Patent Document 2] JP 2013-012535 A [Patent Document 3] WO2016 / 185858 [Patent Document 4] WO2018 / 016465 Summary of the Invention [Problem to be solved by the invention]

[0006] However, photoelectric conversion elements using BTBT-based compounds reported so far have not been able to provide a response speed sufficient for practical use. Patent Document 4 also reports that BTBT-based compounds have an excellent light-to-dark ratio when used in photoelectric conversion elements, but does not describe their response properties. The inventors' evaluation revealed that they did not provide a response speed sufficient for practical use.

[0007] In view of the above circumstances, an object of the present invention is to provide a fused polycyclic aromatic compound that can be used as a material for an organic photoelectric conversion element having an excellent response speed, an organic thin film containing the fused polycyclic aromatic compound, and an organic photoelectric conversion element containing the organic thin film. [Means for solving the problem]

[0008] As a result of intensive investigations, the present inventors have found that the above problems can be solved by using a novel condensed polycyclic aromatic compound having a specific structure, and have thus completed the present invention. That is, the present invention relates to the following [1] to [4]. [1] The following formula (1) [ka] (In formula (1), R 1 represents a substituted or unsubstituted benzothienyl group or a substituted or unsubstituted benzofuranyl group; R 2 and R 3 are each independently a substituted or unsubstituted aromatic hydrocarbon group. [2] A material for photoelectric conversion elements, comprising the compound according to [1]. [3] An organic thin film comprising the material for photoelectric conversion elements according to [2]. [4] An organic photoelectric conversion element comprising the material for photoelectric conversion elements according to [2] or the organic thin film according to [3]. Effect of the Invention

[0009] The present invention can provide a fused polycyclic aromatic compound that can be used as a material for an organic photoelectric conversion element having an excellent response speed, an organic thin film containing the fused polycyclic aromatic compound, and an organic photoelectric conversion element containing the organic thin film. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of an organic photoelectric conversion element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below. The description of the constituent elements described herein is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples.

[0012] [Fused polycyclic aromatic compound] The compound of the present invention is represented by the following formula (1). [ka]

[0013] In formula (1), R 1 represents a substituted or unsubstituted benzothienyl group or a substituted or unsubstituted benzofuranyl group, and is represented by the following formula (2). In formula (2), X represents an oxygen atom or a sulfur atom, and is preferably a sulfur atom. R 2 forms a bond with R 2 The substitution position forming a bond with is preferably b, c, or f, more preferably c or f, and further preferably c. [ka]

[0014] When the benzothienyl group or the benzofuranyl group has a substituent, examples of the substituent include an aromatic hydrocarbon group, and preferably a phenyl group or a naphthyl group.

[0015] R 2 and R 3 Each of the represents independently a substituted or unsubstituted divalent aromatic hydrocarbon group. The divalent aromatic hydrocarbon group is a divalent linking group obtained by removing two hydrogen atoms from an aromatic ring of an aromatic compound. When the divalent aromatic hydrocarbon group has a substituent, the substituent is preferably an aromatic hydrocarbon group, and the substitution position is not particularly limited. Examples of the substituent include a phenyl group and a naphthyl group.

[0016] R 2 and R 3 Specific examples of the divalent aromatic hydrocarbon group represented by the formula (3) include linking groups obtained by removing two hydrogen atoms from an aromatic organic compound selected from benzene, biphenyl, terphenyl, indene, naphthalene, anthracene, fluorene, and phenanthrene, etc. The divalent aromatic hydrocarbon group is preferably a linking group obtained by removing two hydrogen atoms from an aromatic organic compound selected from benzene, biphenyl, and naphthalene, and these linking groups preferably form a bond at a substitution position represented by the following formula (3). [ka]

[0017] R in formula (1) 3 The thiophene ring to which R is bonded may have a substituent on the three unbonded carbon atoms, but preferably has no substituent. 3 The thiophene ring bonded to does not have any further condensed ring structure.

[0018] The fused polycyclic aromatic compound represented by formula (1) can be obtained by coupling reaction of dihalogenated BTBT (2,7-dihalogenobenzo[b]benzo[4,5]thieno[2,3-b]thiophene) represented by the following formula (A), which has been synthesized by a known method, with boronic acid ester derivatives represented by the following formulas (B) and (C), and then isolating the target compound by, for example, sublimation purification.

[0019] [ka]

[0020] X in formula (A) 1 and X 2 R in formula (B) and formula (C) represents a halogen atom. 1 , R 2 , and R 3 is R in Eq. (1). 1 , R 2 , and R 3 and each mean the same thing.

[0021] The method for purifying the condensed polycyclic aromatic compound represented by formula (1) is not particularly limited, and known methods such as recrystallization, column chromatography, and vacuum sublimation purification can be used. Furthermore, these methods can be combined as necessary.

[0022] Specific examples of the fused polycyclic aromatic compound represented by formula (1) are shown below, but the invention is not limited to these specific examples.

[0023] [ka] TIFF2025010080000008.tif171170

[0024] [Photoelectric conversion element materials] The photoelectric conversion element material contains a condensed polycyclic aromatic compound represented by formula (1). The photoelectric conversion element material may contain components other than the condensed polycyclic aromatic compound represented by formula (1) as long as the effects of the present invention are not impaired, but it is preferable that the photoelectric conversion element material contains only the condensed polycyclic aromatic compound represented by formula (1). The content of the condensed polycyclic aromatic compound represented by formula (1) in the photoelectric conversion element material is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 99% by mass or more. Other components that can be used in combination with the condensed polycyclic aromatic compound represented by formula (1) are not particularly limited. The material for photoelectric conversion elements may contain one type of fused polycyclic aromatic compound represented by formula (1) alone or in combination of two or more types. The material for a photoelectric conversion device containing the fused polycyclic aromatic compound represented by formula (1) can be used as a hole transport material for a photoelectric conversion device to realize a photoelectric conversion device with an excellent response speed.

[0025] [Organic thin film] The organic thin film includes the above-mentioned material for photoelectric conversion element. The thickness of the organic thin film may be selected depending on the application, but is usually 1 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 500 nm. The method for forming the organic thin film includes dry processes such as deposition (methods using the material for photoelectric conversion element as it is) and various solution processes (methods using a solution in which the material for photoelectric conversion element is dissolved and / or dispersed in an organic solvent or the like). Examples of the solution process include spin coating, drop casting, dip coating, spraying, letterpress printing such as flexographic printing and resin letterpress printing, offset printing, dry offset printing, and pad printing, intaglio printing such as gravure printing, stencil printing such as screen printing, mimeograph printing, and ring graph printing, inkjet printing, microcontact printing, and the like, as well as a method combining a plurality of these methods. When forming a film by a solution process, it is preferable to evaporate the solvent after the above-mentioned coating or printing to form a thin film.

[0026] [Organic photoelectric conversion element] An organic photoelectric conversion element is an element composed of an organic semiconductor material and electrodes, etc., and is an element that converts light into electricity. FIG. 1 shows an example of an organic photoelectric conversion element. An organic photoelectric conversion element 10 includes a substrate 1, a first electrode 2, an electron blocking layer 3, a photoelectric conversion layer 4, a hole blocking layer 5, and a second electrode 6, in this order. The organic photoelectric conversion element 10 is characterized in that both or one of the electron blocking layer 3 and the photoelectric conversion layer 4 have an organic thin film containing the above-mentioned photoelectric conversion element material as a hole transport material. The organic photoelectric conversion element of the present invention is not limited to the structure of FIG. 1, and layers can be added or omitted as necessary. The organic photoelectric conversion element shown in FIG. 1 can be used, for example, as an organic photoelectric conversion element for imaging.

[0027] -Substrate 1- The substrate 1 is a member that supports the organic photoelectric conversion element 10. There is no particular limitation on the material of the substrate 1, and for example, a substrate made of glass, transparent plastic, quartz, etc. can be used. When light is incident from the second electrode 6 side in FIG. 1, the substrate 1 does not necessarily have to be transparent. Here, "having transparency" means that the transmittance of light of a specific wavelength to be converted into a current is excellent. In addition, a substrate may be further disposed outside the second electrode 6, but at least one of the substrate 1 and the substrate outside the second electrode 6 must be transparent.

[0028] -First electrode 2, second electrode 6- The first electrode 2 and the second electrode 6 have a function of collecting holes and electrons generated in the photoelectric conversion layer 4. Since a function of allowing light to enter the photoelectric conversion layer 4 is also required, at least one of the first electrode 2 and the second electrode 6 must be transparent. The material of the first electrode 2 and the second electrode 6 is not particularly limited as long as it has conductivity, and examples thereof include conductive transparent materials such as ITO, IZO, SnO2, ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO2, and FTO, metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, and tungsten, inorganic conductive materials such as copper iodide and copper sulfide, and conductive polymers such as polythiophene, polypyrrole, and polyaniline. The first electrode 2 and the second electrode 6 may contain a mixture of a plurality of these materials as necessary, or may be a laminate of two or more layers.

[0029] -Electron Block Layer 3- The electron blocking layer 3 is provided to suppress dark current generated when electrons are injected from one electrode into the photoelectric conversion layer 4 when a bias voltage is applied between the two electrodes. It also has a function as a hole transporter that transports holes generated by charge separation in the photoelectric conversion layer 4 to the electrode. The electron blocking layer 3 may be arranged as a single layer or multiple layers as necessary.

[0030] The electron blocking layer 3 can include a P-type organic semiconductor material that is a hole transporting material. The p-type organic semiconductor material is a compound containing a condensed polycyclic aromatic compound represented by the above formula (1). Although materials for photoelectric conversion elements are preferred, other P-type organic semiconductor materials may also be used.

[0031] Other p-type organic semiconductor materials that can be used include, for example, compounds having a condensed polycyclic aromatic group such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, compounds having a π-electron-rich aromatic group such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothienothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and carbazole derivatives, as well as aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0032] -Photoelectric conversion layer 4- The photoelectric conversion layer 4 is a layer in which holes and electrons are generated by charge separation of excitons generated by incident light. The photoelectric conversion layer 4 may be formed only of a photoelectric conversion material, but may be formed in combination with a P-type organic semiconductor material that is a hole transport material or an N-type organic semiconductor material that is an electron transport material. In addition, two or more types of P-type organic semiconductor materials may be used, or two or more types of N-type organic semiconductor materials may be used. It is desirable that one or more of the photoelectric conversion material, P-type organic semiconductor material, and N-type organic semiconductor material contained in the photoelectric conversion layer 4 contain a dye material having a function of absorbing light of a desired wavelength in the visible region. In a preferred embodiment, a material for a photoelectric conversion element containing a condensed polycyclic aromatic compound represented by formula (1) is used as the P-type organic semiconductor material that is a hole transport material.

[0033] The photoelectric conversion material may be any material that generates excitons in response to incident light. For example, compounds having a condensed polycyclic aromatic group such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, compounds having a π-electron-rich aromatic group such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothienothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, and indolocarbazole derivatives, aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives may be used. From the viewpoint of the efficiency of using incident light, a material with a high absorption coefficient is preferable, and for example, pyrromethene derivatives, porphyrin derivatives, subporphyrin derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, quinacridone derivatives, pyrrolopyrrole derivatives, coumarin derivatives, perylene derivatives, and aromatic amine derivatives can be used.

[0034] When the above-mentioned material for photoelectric conversion elements is used as a P-type organic semiconductor material, it may be used in combination with other P-type organic semiconductor materials, and two or more of the above-mentioned materials for photoelectric conversion elements may be used. Other p-type organic semiconductor materials that can be used include, for example, compounds having a condensed polycyclic aromatic group such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having a π-electron-rich aromatic group such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothienothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, and indolocarbazole derivatives; aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives. Examples of the polymeric P-type organic semiconductor material include polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. The polymeric P-type organic semiconductor material may be mixed with the photoelectric conversion element material of the present invention or a non-polymeric P-type organic semiconductor material, or two or more polymeric P-type organic semiconductor materials may be mixed together.

[0035] The N-type organic semiconductor material may be any material having electron transport properties, and examples thereof include naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid diimide, fullerenes, and azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole. One or a combination of two or more selected from these N-type organic semiconductor materials may be used.

[0036] -Hole blocking layer 5- The hole blocking layer 5 is provided to suppress a dark current generated by holes being injected from one electrode into the photoelectric conversion layer 4 when a bias voltage is applied between the two electrodes. The hole blocking layer 5 also functions as an electron transport layer that transports electrons generated by charge separation in the photoelectric conversion layer 4 to the electrode. The hole blocking layer 5 may have a single layer or multiple layers as necessary. The hole blocking layer 5 may be made of an N-type organic semiconductor material having electron transport properties. The N-type organic semiconductor material may be any material having electron transport properties, and examples thereof include polycyclic aromatic polycarboxylic anhydrides such as naphthalene tetracarboxylic diimide and perylene tetracarboxylic diimide, and imidized products thereof, fullerenes such as C60 and C70, azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole, tris(8-quinolinolato)aluminum(III) derivatives, phosphine oxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidene methane derivatives, anthraquinodimethane and anthrone derivatives, bipyridine derivatives, quinoline derivatives, and indolocarbazole derivatives. One or a combination of two or more selected from these N-type organic semiconductor materials may be used.

[0037] The organic photoelectric conversion element 10 is used in solar cells, photosensors, image sensors, photocounters, and It can be used for LIDAR, etc. EXAMPLES

[0038] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means parts by mass, and "%" means % by mass.

[0039] [Example 1: Synthesis of condensed polycyclic aromatic compound No. 1] To DMF (200 parts), diiodo BTBT (4.9 parts) synthesized by the method described in Japanese Patent No. 4945757, pinacol borate derivative (3.4 parts) represented by the following formula (A-1) synthesized by a known method, pinacol borate derivative (3.2 parts) represented by the following formula (B-1) synthesized by a known method, tripotassium phosphate (6.3 parts) and tetrakis (triphenylphosphine) palladium (0.58 parts) were added and stirred at 80 ° C. for 5 hours under a nitrogen atmosphere. The resulting reaction solution was cooled to room temperature, water was added, and the resulting solid was filtered. The resulting solid was washed with acetone, dried and purified by sublimation to obtain a condensed polycyclic aromatic compound (1.0 part, 20% yield) represented by specific example No. 1 as a yellow solid.

[0040] [ka]

[0041] [Example 2: Synthesis of condensed polycyclic aromatic compound No. 2] A condensed polycyclic aromatic compound (1.2 parts, yield 24%) represented by specific example No. 2 was obtained in the same manner as in Example 1, except that the pinacol borate derivative (3.2 parts) represented by formula (B-1) was replaced with a pinacol borate derivative (3.7 parts) represented by the following formula (B-2) synthesized by a known method.

[0042] [ka]

[0043] [Example 3: Synthesis of condensed polycyclic aromatic compound No. 9] The pinacol borate derivative represented by formula (A-1) (3.4 parts) was changed to a pinacol borate derivative represented by the following formula (A-2) synthesized by a known method (3.4 parts), and the pinacol borate derivative represented by formula (B-1) (3.2 parts) was changed to a pinacol borate derivative represented by the following formula (B-3) synthesized by a known method (3.4 parts). Except for this, the same procedure as in Example 1 was followed to obtain a condensed polycyclic aromatic compound represented by specific example No. 9 (1.2 parts, yield 24%).

[0044] [ka]

[0045] [Example 4: Preparation of photoelectric conversion element A] A 70-nm-thick ITO electrode was formed on a glass substrate, and an electron blocking layer was formed on the glass substrate. -5 Under the condition of 10 Pa, CzBDF (manufactured by Tokyo Chemical Industry Co., Ltd.) was formed to a thickness of 10 nm. Next, as a photoelectric conversion layer, the compound represented by No. 1 of the specific example obtained in Example 1, Cl6-SubPc-OPh (manufactured by Lumitec Co., Ltd.) and fullerene (C60, manufactured by Tokyo Chemical Industry Co., Ltd.) were co-evaporated at a deposition rate ratio of 4:4:2 to form an organic thin film having a thickness of 230 nm. Subsequently, 10 nm of commonly available dpy-NDI (manufactured by Tokyo Chemical Industry Co., Ltd.) was evaporated to form a hole blocking layer. Finally, aluminum was deposited to a thickness of 100 nm as an electrode to prepare a photoelectric conversion element A.

[0046] [ka]

[0047] [Example 5: Preparation of photoelectric conversion element B] Photoelectric conversion element B was prepared by the same procedure as in Example 4, except that compound No. 2 obtained in Example 2 was used instead of compound No. 1 of the specific example obtained in Example 1.

[0048] [Example 6: Preparation of photoelectric conversion element C] Photoelectric conversion element C was prepared by the same procedure as in Example 4, except that compound No. 9 obtained in Example 3 was used instead of compound No. 1 of the specific example obtained in Example 1.

[0049] [Comparative Example 1: Preparation of photoelectric conversion element D] The compound represented by No. C1 (3.3 parts, 50%) was obtained in the same manner as in Example 1, except that the pinacol borate derivative represented by formula (A-1) (6.6 parts) was used instead of the pinacol borate derivative represented by formula (A-1) (3.4 parts) and the pinacol borate derivative represented by formula (B-1) (3.2 parts).

[0050] [ka]

[0051] A photoelectric conversion element D was prepared in the same manner as in Example 4, except that the compound represented by No. C1 was used instead of the compound represented by No. 1.

[0052] [Comparative Example 2: Preparation of photoelectric conversion element E] The compound represented by No. C2 (3.0 parts, 45%) was obtained in the same manner as in Example 1, except that the pinacol borate derivative represented by formula (B-1) (6.6 parts) was used instead of the pinacol borate derivative represented by formula (A-1) (3.4 parts) and the pinacol borate derivative represented by formula (B-1) (3.2 parts).

[0053] [ka]

[0054] A photoelectric conversion element E was prepared in the same manner as in Example 4, except that the compound represented by No. C2 was used instead of the compound represented by No. 1.

[0055] (Evaluation of organic photoelectric conversion element) (a) External quantum efficiency (EQE) evaluation An EQE evaluation was carried out based on the examples of WO2018 / 105269. Using the obtained photoelectric conversion elements A to D, the following operation confirmation evaluation was carried out. Specifically, the photoelectric conversion element is charged with 2.0 × 10 5A voltage was applied to give an intensity of 1000 V / cm, and the external quantum efficiency of photoelectric conversion at 550 nm (the efficiency at which incident photons were converted into output electrons, hereinafter also referred to as "photoelectric conversion efficiency") was measured. As a result, it was confirmed that all of the obtained photoelectric conversion elements showed an EQE of 70% or more and functioned satisfactorily as photoelectric conversion elements.

[0056] (b) Evaluation of responsiveness Responsiveness was evaluated based on the examples of WO2018 / 105269. Specifically, the photoelectric conversion element obtained was charged with 2.0 × 10 5 A voltage was applied so that the intensity was 1000 V / cm. Then, an LED (light emitting diode) was momentarily turned on to irradiate light from the lower electrode on the transparent conductive film side, and the photocurrent at that time was measured with an oscilloscope to measure the rise time from 0 to 97% signal intensity. A relative value was then calculated when the rise time of Comparative Example 1 was taken as 10. The results are shown in Table 1. In addition, compared to Comparative Example 1, when the relative value of the rise time was 5 or less, it was marked as "A", when it was more than 5 and less than 8, it was marked as "B", when it was more than 8 and less than 10, it was marked as "C", and when it was 10 or more, it was marked as "D". In practice, it is preferable for the photoelectric conversion element to have a high light response speed, so "A" means the best and "D" means the worst.

[0057] [Table 1]

[0058] As shown in Table 1, the photoelectric conversion elements of Examples 4 to 6 were shown to be superior to the photoelectric conversion elements of Comparative Examples 1 and 2 in terms of the response speed. [Industrial Applicability]

[0059] By using the fused polycyclic aromatic compound represented by formula (1), it is possible to provide an organic semiconductor device (for example, a photoelectric conversion element, an optical sensor, etc.) having excellent responsiveness. [Explanation of symbols]

[0060] 1 Board 2 First electrode 3. Electron Block Layer 4 Photoelectric conversion layer 5 Hole Blocking Layer 6 Second electrode 10 Organic photoelectric conversion element

Claims

1. The following formula (1): 【Chemistry 1】 (In the formula, R １ represents a substituted or unsubstituted benzothienyl group or a substituted or unsubstituted benzofuranyl group; R ２ and R ３ each independently represents a substituted or unsubstituted aromatic hydrocarbon group. A condensed polycyclic aromatic compound represented by the formula:

2. A material for a photoelectric conversion device, comprising the condensed polycyclic aromatic compound according to claim 1 .

3. An organic thin film comprising the material for a photoelectric conversion device according to claim 2 .

4. An organic photoelectric conversion element comprising the material for photoelectric conversion elements according to claim 2 or the organic thin film according to claim 3.

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