Condensed polycyclic aromatic compound, material for photoelectric conversion element, organic thin film, and organic photoelectric conversion element

Abstract

Provided are: an organic compound which is a material for an organic photoelectric conversion element having excellent response speed; an organic thin film comprising the organic compound; and an organic photoelectric conversion element comprising the organic thin film. Provided is a condensed polycyclic aromatic compound represented by formula (1) (in the formula, R1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R3 represents a substituted or unsubstituted aromatic hydrocarbon group, R4 represents a substituted or unsubstituted benzothienyl group, and R4 represents a substituted or unsubstituted benzofuranyl group; and R3 and R4 each independently represent a substituted or unsubstituted aromatic hydrocarbon group or a single bond). [chemical] # imgabs0 #

Description

Technical Field

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

[0002] Organic electronic devices have been actively researched and developed in recent years because they do not contain rare metals and other raw materials and can be stably supplied, and have flexibility that inorganic materials do not have and can be manufactured by wet film forming methods. Specific examples of organic electronic devices include organic electroluminescence (EL) elements, organic solar cell elements, organic photoelectric conversion elements, and organic transistor elements. In addition to the performance of the devices, various uses that effectively utilize the characteristics of organic compounds are also being studied.

[0003] Among the above devices, organic photoelectric conversion elements are used in photosensors and the like, and are studied for use in imaging elements (Patent Document 1). However, imaging elements are required to have a high response speed for capturing moving objects (Patent Document 2).

[0004] In order to meet such demands, studies have been conducted on using BTBT-based compounds, which are organic semiconductor materials known to exhibit high mobility, in photoelectric conversion elements (Patent Document 3).

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] WO2022 / 114065

[0008] [Patent Document 2] Japanese Patent Application Publication No. 2013-012535

[0009] [Patent Document 3] WO2016 / 185858

[0010] [Patent Document 4] WO2018 / 016465 Summary of the invention

[0011] [Problems to be solved by the invention]

[0012] However, in the photoelectric conversion elements using BTBT-based compounds reported so far, a response speed sufficient for practical use cannot be obtained. In addition, in Patent Document 4, a BTBT-based compound having an excellent light-dark ratio by being used in a photoelectric conversion element is reported, but there is no description about the responsiveness. The inventors and others conducted an evaluation and found that a response speed sufficient for practical use could not be obtained.

[0013] In view of the above circumstances, an object of the present invention is to provide a condensed polycyclic aromatic compound as a material for an organic photoelectric conversion element having excellent response speed, an organic thin film comprising the condensed polycyclic aromatic compound, and an organic photoelectric conversion element comprising the organic thin film.

[0014] [Technical means to solve the problem]

[0015] The present inventors have conducted intensive studies and have found that the above-mentioned problems can be solved by using a novel condensed polycyclic aromatic compound having a specific structure, thereby completing the present invention.

[0016] That is, the present invention relates to the following [1] to [6].

[0017] [1] A condensed polycyclic aromatic compound represented by the following formula (1):

[0018]

[0019] (Where R 1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R 3 and R 4 and (each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond).

[0020] [2] The condensed polycyclic aromatic compound according to [1], wherein R 1 represents a substituted or unsubstituted aromatic hydrocarbon group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R 3 and R 4 Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond.

[0021] [3] The condensed polycyclic aromatic compound according to [1], wherein R 1 represents a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group, R 3 and R 4Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond.

[0022] [4] A photoelectric conversion element material comprising the condensed polycyclic aromatic compound according to any one of [1] to [3].

[0023] [5] An organic thin film comprising the photoelectric conversion element material according to [4].

[0024] [6] An organic photoelectric conversion element comprising the photoelectric conversion element material according to [4] or the organic thin film according to [5].

[0025] [Effects of the Invention]

[0026] The present invention can provide a condensed polycyclic aromatic compound as a material for an organic photoelectric conversion element having excellent response speed, an organic film comprising the condensed polycyclic aromatic compound, and an organic photoelectric conversion element comprising the organic film. In addition, in this specification, the condensed polycyclic aromatic compound of the present invention is sometimes referred to as "the compound of the present invention". BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic cross-sectional view showing one embodiment of an organic photoelectric conversion element.

[0028] [Explanation of Symbols]

[0029] 1: Substrate

[0030] 2: First electrode

[0031] 3: Electron blocking layer

[0032] 4: Photoelectric conversion layer

[0033] 5: Hole blocking layer

[0034] 6: Second electrode

[0035] 7: Organic photoelectric conversion element DETAILED DESCRIPTION

[0036] The contents of the present invention will be described in detail below. The description of the constituent elements described here is based on representative embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples.

[0037] [Condensed polycyclic aromatic compounds]

[0038] The compound of the present invention is represented by the following formula (1). 2 and R 3 The bonded condensed polycyclic aromatic ring is called a BTBT ring.

[0039]

[0040] (Where R 1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R 3 and R 4 Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond)

[0041] In formula (1), as R 1 Specific examples of the aromatic hydrocarbon group represented by include phenyl, biphenyl, indenyl, naphthyl, anthracenyl, fluorenyl, and phenanthryl. Phenyl, biphenyl, and naphthyl are preferred, and phenyl and biphenyl are more preferred.

[0042] In formula (1), R 1 It may also represent a substituted or unsubstituted benzothienyl or benzofuranyl group, and may be represented by the following formula (2). In formula (2), X represents an oxygen atom or a sulfur atom, preferably a sulfur atom. In one of the substitution positions selected from a to f, R 2 Form a bond. With R 2 The substitution position for forming a bond is preferably b, c, and f, more preferably c and f, and still more preferably c.

[0043]

[0044] When the benzothienyl group or the benzofuranyl group has a substituent, examples of the substituent include aromatic hydrocarbon groups, and a phenyl group and a naphthyl group are preferred.

[0045] R 2 represents a substituted or unsubstituted divalent aromatic hydrocarbon group, or a single bond. A divalent aromatic hydrocarbon group is a divalent linking group obtained by removing two hydrogen atoms from the aromatic ring of an aromatic hydrocarbon 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 phenyl and naphthyl. The so-called R 2 When it is a single bond, R 1 Directly bonded to the BTBT ring.

[0046] As R 2 Specific examples of the divalent aromatic hydrocarbon group represented by include a linking group obtained by removing two hydrogen atoms from an aromatic organic compound selected from benzene, biphenyl, indene, naphthalene, anthracene, fluorane and phenanthrene, preferably benzene, biphenyl and naphthalene, more preferably benzene and biphenyl. Benzene, biphenyl and naphthalene are preferably substituted at the position indicated by the wavy line below and R 1The 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).

[0047]

[0048] In R 1 and R 2 When both are aromatic hydrocarbon groups, R 1 With R 2 Specific examples of the combination include combinations represented by the following formulae (1A-1) to (1A-2), (1B-1) to (1B-4), and (1C-1) to (1C-4). In the formula, * represents a site bonded to the BTBT ring. Among them, a combination represented by any one of formulae (1A-1) to (1A-2) and (1B-1) to (1B-4) is preferred, and a combination represented by formulae (1A-1) to (1A-2) is more preferred.

[0049]

[0050] *Indicates the junction with the BTBT ring.

[0051] R 3 and R 4 represents a substituted or unsubstituted divalent aromatic hydrocarbon group or a single bond. A divalent aromatic hydrocarbon group is a divalent linking group obtained by removing two hydrogen atoms from the aromatic ring of an aromatic hydrocarbon 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. 3 is a single bond and R 4 In the case of a substituted or unsubstituted divalent aromatic hydrocarbon group, R 4 Directly bonded to the BTBT ring. 3 is a substituted or unsubstituted divalent aromatic hydrocarbon group and R 4 In the case of a single bond, the thiophene ring is directly bonded to R 3 Bond. 3 and R 4 In the case of a single bond, the thiophene ring is directly bonded to the BTBT ring.

[0052] As R 3 and R 4 Specific examples of the divalent aromatic hydrocarbon group represented by include a linking group obtained by removing two hydrogen atoms from an aromatic organic compound selected from benzene, biphenyl, indene, naphthalene, anthracene, fluorane and phenanthrene, preferably benzene, biphenyl and naphthalene, more preferably benzene and biphenyl. Benzene, biphenyl and naphthalene are preferably substituted at the position indicated by the wavy line below with the thiophene ring, R3 , R 4 Or BTBT ring bond.

[0053]

[0054] As R 3 , R 4 Specific examples of the combination of thiophene rings include the following combinations represented by formula (2A-1) to (2A-2), formula (2B-1) to (2B-2) and formula (2C-1) to (2C-3). In the formula, * represents the site bonded to the BTBT ring. Among them, a combination represented by any one of formula (2A-1) to (2A-2) and formula (2B-1) to (2B-2) is preferred, and a combination represented by formula (2A-1) to (2A-2) is more preferred.

[0055]

[0056] *Indicates the junction with the BTBT ring.

[0057] R in formula (1) 3 and R 4 In the terminal thiophene ring on one side (ie, the right terminal thiophene ring in formula (1)), the three unbonded carbon atoms may have a substituent, but preferably have no substituent. The thiophene ring does not have any more condensed ring structures.

[0058] The compound of the present invention can be obtained by subjecting a dihalogenated BTBT (2,7-dihalogenobenzo[b]benzo[4,5]thieno[2,3-b]thiophene) represented by the following formula (A) synthesized by a known method to a coupling reaction with a borate ester derivative represented by the following formula (B) and formula (C), and then extracting the target compound by, for example, sublimation purification.

[0059]

[0060] X in formula (A) represents a halogen atom. R in formula (B) and formula (C) 1 , R 2 , R 3 and R 4 Respectively with R in formula (1) 1 , R 2 , R 3 and R 4 Meaning the same.

[0061] The method for purifying the compound of the present invention is not particularly limited, and known methods such as recrystallization, column chromatography, and vacuum sublimation purification can be used. In addition, these methods can be combined as necessary.

[0062] Specific examples of the compound of the present invention are shown below, but the present invention is not limited to these specific examples.

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] [Materials for photoelectric conversion elements]

[0069] The photoelectric conversion element material contains the compound of the present invention. As long as it is within the range of not damaging the effect of the present invention, the photoelectric conversion element material may also contain components other than the condensed polycyclic aromatic compound represented by formula (1), but preferably only contains the compound of the present invention. The content of the compound of the present invention in the photoelectric conversion element material is preferably 80 mass % or more, more preferably 90 mass % or more, and further preferably 95 mass % or more, particularly preferably 98 mass % or more, and most preferably 99 mass % or more. Other components that can be used in combination with the compound of the present invention are not particularly limited.

[0070] Furthermore, one or more condensed polycyclic aromatic compounds represented by the formula (1) may be used in the photoelectric conversion element material.

[0071] The photoelectric conversion element material containing the compound of the present invention can realize a photoelectric conversion element having an excellent response speed by using it as a hole transport material of the photoelectric conversion element.

[0072] [Organic thin film]

[0073] The organic film of the present invention includes the photoelectric conversion element material of the present invention. The film thickness of the organic film can be selected according to its use, but it is usually 1nm to 1μm, preferably 5nm to 500nm, and more preferably 10nm to 500nm. Regarding the formation method of the organic film, dry processes such as evaporation (a method of directly using the photoelectric conversion element material) or various solution processes (a method of using a solution obtained by dissolving and / or dispersing the photoelectric conversion element material in an organic solvent, etc.) can be cited. As a solution process, for example, spin coating, drop casting, dip coating, spraying, flexographic printing, resin relief printing and other relief printing methods, offset printing, dry offset printing, pad printing and other flat printing methods, gravure printing and other gravure printing methods, screen printing, mimeograph printing, micro-printing and other hole printing methods, inkjet printing, micro-contact printing, etc., and a method of combining these methods in a variety of ways. In the case of film formation using a solution process, it is preferably after the coating or printing, the solvent is evaporated to form a film.

[0074] [Organic photoelectric conversion element]

[0075] An organic photoelectric conversion element is an element including an organic semiconductor material, an electrode, and the like, and is an element that converts light into electricity. Figure 1 An example of an organic photoelectric conversion element is shown. The organic photoelectric conversion element 7 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 7 is characterized in that both or one of the electron blocking layer 3 and the photoelectric conversion layer 4 has an organic thin film including the photoelectric conversion element material of the present invention as a hole transport material. The organic photoelectric conversion element of the present invention is not limited to Figure 1 The structure can add or omit layers as needed. Figure 1 The organic photoelectric conversion element shown in can be used as an organic photoelectric conversion element for imaging, for example.

[0076] -Substrate 1-

[0077] The substrate 1 is a member that supports the organic photoelectric conversion element 7. The material of the substrate 1 is not particularly limited, and for example, materials including glass, transparent plastic, quartz, etc. can be used. Figure 1 In the case where the incident light is incident from the second electrode 6 side, the substrate 1 may not necessarily be transparent. Here, "having transparency" means that the transmittance of the light of a specific wavelength to be converted into electric current is excellent. In addition, a further substrate may be arranged outside the second electrode 6, but at least one of the substrate 1 and the substrate outside the second electrode 6 needs to be transparent.

[0078] -First electrode 2, second electrode 6-

[0079] The first electrode 2 and the second electrode 6 have the function of capturing holes and electrons generated in the photoelectric conversion layer 4. Since the photoelectric conversion layer 4 also needs to have the function of allowing light to enter, at least one of the first electrode 2 and the second electrode 6 needs to be transparent. The materials of the first electrode 2 and the second electrode 6 are not particularly limited as long as they are conductive materials, and examples thereof include indium tin oxide (ITO), indium zinc oxide (IZO), SnO 2 、ATO(Antimony-doped Tin Oxide)(Antimony-doped Tin Oxide), ZnO, AZO(Aluminum-doped Zinc Oxide)(Aluminum-doped Zinc Oxide), GZO(Gallium-doped Zinc Oxide)(Gallium-doped Zinc Oxide), TiO 2 and conductive transparent materials such as fluorine-doped tin oxide (FTO); metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel and tungsten; inorganic conductive substances such as copper iodide and copper sulfide; conductive polymers such as polythiophene, polypyrrole and polyaniline, etc. The first electrode 2 and the second electrode 6 may also contain a mixture of various materials as needed, and may also be formed by stacking two or more layers.

[0080] -Electron blocking layer 3-

[0081] The electron blocking layer 3 is provided to suppress dark current generated when a bias voltage is applied between the two electrodes due to electron injection from one of the electrodes into the photoelectric conversion layer 4. In addition, it also functions as a hole transport layer for transporting holes generated by charge separation in the photoelectric conversion layer 4 to the electrode. The electron blocking layer 3 can be configured as a single layer or multiple layers as needed.

[0082] The electron blocking layer 3 may include a P-type organic semiconductor material as a hole transport material. The P-type organic semiconductor material is preferably a photoelectric conversion element material containing a condensed polycyclic aromatic compound represented by formula (1), but may be other P-type organic semiconductor materials.

[0083] As other P-type organic semiconductor materials, for example, naphthalene, anthracene, phenanthrene, pyrene, Compounds having condensed polycyclic aromatic groups such as tetracene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having π-electron excess aromatic groups such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and carbazole derivatives; and aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0084] -Photoelectric conversion layer 4-

[0085] The photoelectric conversion layer 4 is a layer that generates holes and electrons by charge separation of excitons generated by incident light. The photoelectric conversion layer 4 can be formed only by a photoelectric conversion material, or it can be formed in combination with a P-type organic semiconductor material as a hole transport material, or an N-type organic semiconductor material as an electron transport material. In addition, two or more P-type organic semiconductor materials can be used, and two or more N-type organic semiconductor materials can also be used. One or more of the photoelectric conversion materials, P-type organic semiconductor materials, and N-type organic semiconductor materials contained in the photoelectric conversion layer 4 preferably contain a pigment material having the function of absorbing light of a desired wavelength in the visible region. A preferred form is to use a photoelectric conversion element material containing a compound of the present invention with respect to a P-type organic semiconductor material as a hole transport material.

[0086] As the photoelectric conversion material, any material that generates excitons by incident light may be used, and examples thereof include naphthalene, anthracene, phenanthrene, pyrene, Compounds having condensed polycyclic aromatic groups such as tetracene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having π-electron excess aromatic groups 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. From the perspective of the efficiency of incident light utilization, materials with high absorption coefficients are preferred, for example, pyrrole methylene derivatives, porphyrin derivatives, subporphyrin derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, quinacridone derivatives, pyrrolopyrrole derivatives, coumarin derivatives, perylene derivatives, and aromatic amine derivatives.

[0087] When the photoelectric conversion element material is used as a P-type organic semiconductor material, it may be used in combination with other P-type organic semiconductor materials, or two or more types of the photoelectric conversion element materials may be used.

[0088] As other P-type organic semiconductor materials, for example, naphthalene, anthracene, phenanthrene, pyrene, Compounds having condensed polycyclic aromatic groups such as tetracene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having π-electron excess aromatic groups such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothiophene 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.

[0089] In addition, as polymeric P-type organic semiconductor materials, polyphenylene vinyl derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives can be exemplified. In addition, the photoelectric conversion element material of the present invention or the non-polymeric P-type organic semiconductor material can be mixed with the polymeric P-type organic semiconductor material, and two or more polymeric P-type organic semiconductor materials can be mixed and used.

[0090] As an N-type organic semiconductor material, any material with electron transport properties can be used, for example: naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid diimide, fullerenes, imidazole, thiazole, thiadiazole, oxazole, oxadiazole, triazole and other azole derivatives, and a single one or a combination of two or more selected from these N-type organic semiconductor materials can be used.

[0091] -Hole blocking layer 5-

[0092] The hole blocking layer 5 is provided to suppress dark current generated by hole injection from one of the electrodes into the photoelectric conversion layer 4 when a bias voltage is applied between the two electrodes. In addition, the hole blocking layer 5 also has a function 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 required. An N-type organic semiconductor material having electron transport properties may be used in the hole blocking layer 5.

[0093] As the N-type organic semiconductor material, any material having electron transport properties may be used, and examples thereof include: polycyclic aromatic polycarboxylic acid anhydrides or imides thereof such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide; 60 or C 70Fullerenes such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, triazole and other azole derivatives; tris(8-hydroxyquinoline)aluminum(III) derivatives, phosphine oxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide, fluorenyl methane derivatives, anthraquinone dimethane and anthrone derivatives, bipyridine derivatives, quinoline derivatives, indolecarbazole derivatives, etc., and a single one or a combination of two or more selected from these N-type organic semiconductor materials can be used.

[0094] The organic photoelectric conversion element 7 can be used for solar cells, light sensors, imaging elements, photon counters, and laser radars (Light Detection and Ranging, LIDAR).

[0095] Example

[0096] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. "Parts" in the Examples refer to parts by mass, and "%" refers to mass %.

[0097] [Example 1: Synthesis of Condensed Polycyclic Aromatic Compound No. 10]

[0098] Dimethylformamide (DMF) (200 parts) was added with diiodo BTBT (4.9 parts) synthesized by the method described in Japanese Patent No. 4945757, a compound represented by the following formula (A-1) synthesized by a known method as a pinacol borate derivative A (2.8 parts), a compound represented by the following formula (B-1) synthesized by a known method as a pinacol borate derivative B (3.6 parts), tripotassium phosphate (6.3 parts) and tetrakis(triphenylphosphine)palladium (0.58 parts), and stirred at 80°C for five hours under a nitrogen atmosphere. The obtained reaction solution was cooled to room temperature, water was added, and the generated solid was separated by filtration. The obtained solid was washed with acetone and dried and then sublimated and purified to obtain the condensed polycyclic aromatic compound represented by Specific Example No. 10 (1.2 parts, yield 19%) as a yellow solid.

[0099]

[0100] [Example 2: Synthesis of Condensed Polycyclic Aromatic Compound No. 16]

[0101] The pinacol borate derivative A was changed to a compound represented by the formula (A-2) synthesized by a known method (3.6 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-2) synthesized by a known method (2.9 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 16 (1.5 parts, yield 24%) was obtained by the same procedure as in Example 1.

[0102]

[0103] [Example 3: Synthesis of Condensed Polycyclic Aromatic Compound No. 45]

[0104] The pinacol borate derivative A was changed to a compound represented by the formula (A-3) synthesized by a known method (3.3 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-1) synthesized by a known method (3.6 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 45 (1.8 parts, yield 27%) was obtained by the same procedure as in Example 1.

[0105]

[0106] [Example 4: Synthesis of Condensed Polycyclic Aromatic Compound No. 19]

[0107] The pinacol borate derivative A was changed to a compound represented by the formula (A-2) synthesized by a known method (3.6 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-3) synthesized by a known method (3.4 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 19 (2.7 parts, yield 39%) was obtained by the same procedure as in Example 1.

[0108]

[0109] [Example 5: Synthesis of Condensed Polycyclic Aromatic Compound No. 57]

[0110] The pinacol borate derivative A was changed to a compound represented by the formula (A-4) synthesized by a known method (3.4 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-2) synthesized by a known method (3.2 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 57 (1.0 part, yield 17%) was obtained by the same procedure as in Example 1.

[0111]

[0112]

[0113] [Example 6: Synthesis of Condensed Polycyclic Aromatic Compound No. 58]

[0114] The pinacol borate derivative A was changed to a compound represented by the formula (A-4) synthesized by a known method (3.2 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-1) synthesized by a known method (3.7 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 58 (1.2 parts, yield 24%) was obtained by the same procedure as in Example 1.

[0115]

[0116] [Example 7: Synthesis of Condensed Polycyclic Aromatic Compound No. 65]

[0117] The pinacol borate derivative A was changed to a compound represented by the formula (A-5) synthesized by a known method (3.4 parts), and the pinacol borate derivative B was changed to a compound represented by the following formula (B-3) synthesized by a known method (3.4 parts). In addition, the condensed polycyclic aromatic compound represented by Specific Example No. 65 (1.2 parts, yield 18%) was obtained by the same procedure as in Example 1.

[0118]

[0119] [Example 8: Fabrication of Photoelectric Conversion Element A]

[0120] On a glass substrate on which an electrode including 70 nm thick ITO was formed as an electron blocking layer, the substrate temperature was room temperature and the vacuum degree was 4.0×10 -5 CzBDF (manufactured by Tokyo Chemical Industry Co., Ltd.) was formed into a film with a thickness of 10 nm under the condition of 1.5 % and 2.5 % Pa. Next, as a photoelectric conversion layer, the compound represented by Specific Example No. 10 obtained in Example 1, Cl 6 -SubPc-OPh (produced by Lumitec) and fullerene (C 60 , manufactured by Tokyo Chemical Industry Co., Ltd.) was co-deposited at a deposition rate ratio of 4:4:2 to form an organic thin film with a thickness of 230nm. Next, dpy-NDI (manufactured by Tokyo Chemical Industry Co., Ltd.), which is commonly available, was deposited at a thickness of 10nm to form a hole blocking layer. Finally, aluminum was deposited at a thickness of 100nm as an electrode to produce a photoelectric conversion element A.

[0121]

[0122] [Example 9: Fabrication of Photoelectric Conversion Element B]

[0123] A photoelectric conversion element B was produced by the same operation as in Example 8 except that the compound No. 16 obtained in Example 2 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0124] [Example 10: Fabrication of Photoelectric Conversion Element C]

[0125] A photoelectric conversion element C was produced by the same operation as in Example 8 except that the compound No. 45 obtained in Example 3 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0126] [Example 11: Fabrication of Photoelectric Conversion Element D]

[0127] A photoelectric conversion element D was produced by the same operation as in Example 8 except that the compound No. 19 obtained in Example 4 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0128] [Example 12: Fabrication of Photoelectric Conversion Element E]

[0129] A photoelectric conversion element E was produced by the same operation as in Example 8 except that the compound No. 57 obtained in Example 5 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0130] [Example 13: Fabrication of Photoelectric Conversion Element F]

[0131] A photoelectric conversion element F was produced by the same operation as in Example 8 except that the compound No. 58 obtained in Example 6 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0132] [Example 14: Fabrication of Photoelectric Conversion Element G]

[0133] A photoelectric conversion element G was produced by the same operation as in Example 8 except that the compound No. 65 obtained in Example 7 was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0134] [Comparative Example 1: Preparation of Photoelectric Conversion Element X]

[0135] Except that a pinacol borate derivative (6.6 parts) represented by formula (B-2) was used instead of the pinacol borate derivative (2.8 parts) represented by formula (A-1) and the pinacol borate derivative (3.6 parts) represented by formula (B-1), a compound represented by formula (X) (3.0 parts, 61%) was obtained by the same procedure as in Example 1.

[0136]

[0137] A photoelectric conversion element X was prepared by the same operation as in Example 8 except that the compound represented by formula (X) was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0138] [Comparative Example 2: Preparation of Photoelectric Conversion Element Y]

[0139] A photoelectric conversion element Y was prepared by the same operation as in Example 8 except that a compound represented by the following formula (Y) synthesized by a known method was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0140]

[0141] [Comparative Example 3: Preparation of Photoelectric Conversion Element Z]

[0142] Except that a pinacol borate derivative (6.6 parts) represented by formula (A-4) was used instead of the pinacol borate derivative (3.4 parts) represented by formula (A-1) and the pinacol borate derivative (3.2 parts) represented by formula (B-1), a compound represented by formula (Z) (3.3 parts, 67%) was obtained by the same procedure as in Example 1.

[0143]

[0144] A photoelectric conversion element Z was prepared by the same operation as in Example 8 except that the compound represented by formula (Z) was used instead of the compound represented by Specific Example No. 10 obtained in Example 1.

[0145] (Evaluation of organic photoelectric conversion element)

[0146] (a) External Quantum Efficiency (EQE) evaluation

[0147] The EQE was evaluated based on the embodiment of WO2018 / 105269. Using the obtained photoelectric conversion elements A to B, photoelectric conversion element X, and photoelectric conversion element Y, the following operation confirmation evaluation was performed.

[0148] Specifically, a voltage of 2.0×10 5 The external quantum efficiency of photoelectric conversion (the efficiency of converting incident photons into output electrons, hereinafter also referred to as “photoelectric conversion efficiency”) at 550 nm was measured with an intensity of 1 V / cm.

[0149] As a result, all the obtained photoelectric conversion elements showed an EQE of 70% or more, and it was confirmed that they fully functioned as photoelectric conversion elements.

[0150] (b) Evaluation of responsiveness

[0151] The responsiveness was evaluated based on the examples of WO2018 / 105269.

[0152] Specifically, a voltage of 2.0×10 5 V / cm. Then, the LED (light emitting diode) was instantly lit to irradiate light from the lower electrode on the transparent conductive film side, and the photocurrent at this time was measured using an oscilloscope, and the rise time from 0 to 97% of the signal intensity was measured. Then, the relative value when the rise time of Comparative Example 1 was set to 10 was obtained. The results are shown in Table 1.

[0153] In addition, with respect to Comparative Example 3, the case where the relative value of the rise time is 5 or less is designated as "A", the case where it is greater than 5 and less than 8 is designated as "B", the case where it is greater than 8 and less than 10 is designated as "C", and the case where it is greater than 10 is designated as "D".

[0154] In practical terms, the photoresponse speed of the photoelectric conversion element is preferably fast, so "A" means the best and "D" means the worst.

[0155] [Table 1]

[0156]

[0157] As shown in Table 1, the photoelectric conversion elements of Examples 8 to 14 were superior to the photoelectric conversion elements of Comparative Examples 1 to 3 in terms of response speed.

[0158] [Industrial Applicability]

[0159] By using the condensed polycyclic aromatic compound represented by the formula (1), an organic semiconductor device (for example, a photoelectric conversion element, a photosensor, etc.) having excellent responsiveness can be provided.

Claims

1. A condensed polycyclic aromatic compound represented by the following formula (1): In the formula, R 1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R 3 and R 4 Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond.

2. The condensed polycyclic aromatic compound according to claim 1, wherein R 1 represents a substituted or unsubstituted aromatic hydrocarbon group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond, R 3 and R 4 Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond.

3. The condensed polycyclic aromatic compound according to claim 1, wherein R 1 represents a substituted or unsubstituted benzothienyl group, or a substituted or unsubstituted benzofuranyl group, R 2 represents a substituted or unsubstituted aromatic hydrocarbon group, R 3 and R 4 Each independently represents a substituted or unsubstituted aromatic hydrocarbon group or a single bond. 4 . A photoelectric conversion element material comprising the condensed polycyclic aromatic compound according to claim 1 . 5 . An organic thin film comprising the photoelectric conversion element material according to claim 4 . 6 . An organic photoelectric conversion element, comprising the photoelectric conversion element material according to claim 4 or the organic thin film according to claim 5 .

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