Anthracene derivative, organic semiconductor material, material for photoelectric conversion element, organic thin film and organic photoelectric conversion element

Abstract

To provide an anthracene derivative which is an organic photoelectric conversion material with excellent external quantum yield (EQE), dark current and response speed when used as a photoelectric conversion element, and materials for photoelectric conversion elements, organic thin films, and organic photoelectric conversion elements using the same.SOLUTION: Anthracene derivatives represented by the following formula (1) (in Formula (1), X and Y each independently represent a divalent aromatic hydrocarbon group, a divalent heterocyclic group, or a single bond. However, the case where both X and Y are single bonds is excluded) are provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a novel anthracene derivative, and to an organic semiconductor material, a material for a photoelectric conversion device, an organic thin film, and an organic photoelectric conversion device each using the same. [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. For example, organic thin-film devices such as organic electroluminescence (EL) elements, field effect transistors, and organic photoelectric conversion elements have attracted attention, and various organic electronics materials, such as condensed polycyclic aromatic compounds, used in these thin-film devices have been researched and developed.

[0003] Among the above devices, organic photoelectric conversion elements are used in optical sensors and the like, and their use in image sensors, for example, is being considered (Patent Document 1). When used as an image sensor, it is important to improve the external quantum efficiency (hereinafter abbreviated as EQE), which indicates the degree to which irradiated light is efficiently converted into electrical energy, and to suppress the current value (dark current) when no light is irradiated. In addition to these characteristics, image sensors are required to have a high response speed when switching light irradiation ON / OFF in order to clearly capture moving objects (Patent Document 2).

[0004] In order to satisfy such required characteristics, a bulk heterojunction structure that uses a mixed film of a P-type organic semiconductor and an N-type organic semiconductor in the photoelectric conversion layer of an organic photoelectric conversion element is currently being studied, and studies are being conducted to simultaneously improve the EQE and suppress the dark current value. In such research and development, an example of using an anthracene derivative as a P-type organic semiconductor is known (Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2022 / 114065 [Patent Document 2] Patent No. 6674547 [Patent Document 3] JP 2023-122010 A [Patent Document 4] JP 2019-134049 A [Patent Document 5] JP 2018-93191 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, among the photoelectric conversion elements using anthracene derivatives reported so far, none have all of EQE, dark current, and response speed. Patent Document 4 reports a photoelectric conversion element using an anthracene derivative, but does not describe its response. In addition, the inventors' evaluation revealed that the dark current and response speed were not sufficient for practical use.

[0007] One of the causes of dark current is the generation of unwanted charges due to thermal excitation from the HOMO (Highest Occupied Molecular Orbital) level of the P-type organic semiconductor to the LUMO (Lowest Unoccupied Molecular Orbital) level of the N-type organic semiconductor at the PN interface of the organic semiconductor blend film. This dark current is more likely to occur as the energy of the HOMO level of the P-type organic semiconductor and the LUMO level of the N-type organic semiconductor approach each other, and conversely, the dark current can be suppressed as the energy difference is larger (Patent Document 5). Therefore, in order to suppress dark current, a material with a sufficiently low energy level of the HOMO of the P-type organic semiconductor is preferable.

[0008] In view of the above circumstances, the present invention aims to provide an anthracene derivative that, when used as a photoelectric conversion material, provides an organic photoelectric conversion element excellent in external quantum efficiency (EQE), dark current and response speed, and a photoelectric conversion element material, an organic thin film, and an organic photoelectric conversion element using the same. [Means for solving the problem]

[0009] As a result of intensive research, the present inventors have found that an anthracene derivative having 3-position-bonded thienyl groups at both ends of the molecule has a low HOMO level energy. They also found that the use of this derivative in a photoelectric conversion element can suppress dark current and provide a good response speed, thus solving the above problems and completing the present invention.

[0010] That is, the present invention relates to the following [1] to

[10] . [1] The following formula (1) [ka] (In formula (1), X and Y each independently represent a divalent aromatic hydrocarbon group, a divalent heterocyclic group, or a single bond, except for the case where both X and Y are single bonds.) An anthracene derivative represented by the formula: [2] The anthracene derivative according to [1], wherein X and Y are the same. [3] The anthracene derivative according to [1], wherein X and Y are different from each other. [4] The anthracene derivative according to the above [1], wherein X and Y each independently represent a divalent aromatic hydrocarbon group. [5] The anthracene derivative according to the above [1], wherein the HOMO energy level is −5.70 eV or less. [6] An organic semiconductor material containing the anthracene derivative according to [1]. [7] A material for photoelectric conversion elements, comprising the anthracene derivative according to [1]. [8] An organic thin film comprising the anthracene derivative according to [1], the organic semiconductor material according to [6], or the material for a photoelectric conversion element according to [7]. [9] An organic photoelectric conversion element having the organic thin film according to [8]. Effect of the Invention

[0011] The present invention can provide an anthracene derivative that serves as an organic photoelectric conversion material excellent in external quantum efficiency (EQE), dark current and response speed when used as a photoelectric conversion element, as well as a photoelectric conversion element material, an organic thin film, and an organic photoelectric conversion element using the same. [Brief description of the drawings]

[0012] [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

[0013] [Anthracene derivatives] The anthracene derivative of the present invention is represented by the following formula (1).

[0014] [ka]

[0015] In formula (1), X and Y each independently represent a divalent aromatic hydrocarbon group, a divalent heterocyclic group, or a single bond, except for the case where both X and Y are single bonds.

[0016] A divalent aromatic hydrocarbon group is a divalent linking group obtained by removing two arbitrary hydrogen atoms from an aromatic ring of an aromatic hydrocarbon compound. The number of carbon atoms in the aromatic hydrocarbon compound that can be a divalent linking group is preferably 6 to 30, more preferably 6 to 18, and even more preferably 6 to 12. The aromatic hydrocarbon compound that can be a divalent linking group is not particularly limited as long as it is a hydrocarbon compound having aromaticity. Examples of the divalent aromatic hydrocarbon group include a linking group obtained by removing two hydrogen atoms from an aromatic hydrocarbon compound selected from benzene, naphthalene, biphenyl, anthracene, terphenyl, phenanthrene, tetracene, chrysene, pyrene, fluorene, phenylnaphthalene, and diphenylnaphthalene, and a linking group obtained by removing two hydrogen atoms from an aromatic hydrocarbon compound obtained by forming a bond between two or more compounds selected from these aromatic hydrocarbon compounds. The divalent aromatic hydrocarbon group is preferably a divalent linking group obtained by removing two hydrogen atoms from benzene, naphthalene, biphenyl, anthracene, terphenyl, or phenylnaphthalene, and more preferably a divalent linking group obtained by removing two hydrogen atoms from benzene, naphthalene, biphenyl, or terphenyl. The divalent aromatic hydrocarbon group may have a substituent, and the substituent that may be had is not particularly limited.

[0017] The divalent heterocyclic group is a divalent linking group obtained by removing two arbitrary hydrogen atoms from a heterocyclic compound. The number of carbon atoms in the heterocyclic compound that can form the divalent linking group is, for example, 3 to 20, preferably 3 to 12, more preferably 3 to 11, and even more preferably 3 to 8. The heterocyclic compound that can form the divalent linking group is not particularly limited as long as it is a compound containing a heterocycle, and the above aromatic hydrocarbon compound and heterocycle can also form a bond to form a divalent linking group. Examples of the divalent heterocyclic group include a linking group obtained by removing two hydrogen atoms from a heterocyclic compound selected from furan, thiophene, thienothiophene, pyrrole, imidazole, thiazole, oxazole, pyridine, phenylpyridine, pyrazine, pyrimidine, benzofuran, benzothiophene, benzothiazole, phenylthiophene, biphenylthiophene, etc., or a linking group obtained by removing two hydrogen atoms from a heterocyclic compound obtained by forming a bond between two or more compounds selected from these heterocyclic compounds. As the heterocyclic compound, a divalent linking group obtained by removing two hydrogen atoms from furan, thiophene, thienothiophene, benzofuran, benzothiophene, phenylthiophene, and biphenylthiophene is preferable, and a divalent linking group obtained by removing two hydrogen atoms from thiophene, thienothiophene, and benzothiophene is more preferable. The divalent heterocyclic group may have a substituent, and the substituent that may be present is not particularly limited.

[0018] There is no further condensed ring structure on the two thiophene rings at the molecular terminals in formula (1), and the three unbonded carbon atoms on the thiophene ring do not have substituents.

[0019] Next, a method for synthesizing the anthracene derivative represented by formula (1) will be described. The anthracene derivative represented by formula (1) can be synthesized using commercially available 2,6-dibromoanthracene. When X and Y are the same, it can be synthesized by performing a coupling reaction using 2 equivalents of the boronic acid derivative represented by the following formula (S) (Reaction Scheme A). On the other hand, when X and Y are different from each other, it can be synthesized by sequentially performing a coupling reaction between the boronic acid derivative represented by the following formula (S) and the boronic acid derivative represented by the following formula (T) (Reaction Scheme B).

[0020] [ka]

[0021] [ka]

[0022] R in formula (S) and formula (T) 1 , R 2 , R 3 , and R 4 each independently represents a hydrogen atom or an alkyl group; R 1 and R 2 , and R 3 and R 4 may be bonded to each other to form a ring. In formula (S) and formula (T), X and Y have the same meanings as X and Y in formula (1).

[0023] The method for purifying the anthracene derivative 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.

[0024] Specific examples of the anthracene derivative represented by formula (1) are shown below, but the invention is not limited to these examples.

[0025] [ka] TIFF2025079668000007.tif81170

[0026] [Organic semiconductor materials (hole transport materials)] The organic semiconductor material contains an anthracene derivative represented by formula (1). The organic semiconductor material may contain components other than the compound represented by formula (1) as long as the effects of the present invention are not impaired, but it is preferable that the organic semiconductor material contains only the compound represented by formula (1). The content of the compound represented by formula (1) in the organic semiconductor 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. By the content of the anthracene derivative represented by formula (1) in the organic semiconductor material being within the above-mentioned preferred range, the energy level of the HOMO of the organic semiconductor material can be made sufficiently low. The organic semiconductor material may contain one or more types of anthracene derivatives represented by formula (1).

[0027] The organic semiconductor material is suitable for use as a hole transport material in various organic electronics devices such as an organic thin-film solar cell element, an organic EL element, an organic transistor element, an organic photoelectric conversion element, etc. For example, the organic semiconductor material is used as a hole transport material for an organic photoelectric conversion element (hereinafter also referred to as a "photoelectric conversion element material"), thereby realizing a photoelectric conversion element that is excellent in all of EQE, dark current, and response speed.

[0028] [Organic thin film] The organic thin film is characterized by including the organic semiconductor material. 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, and more preferably 10 nm to 500 nm. Methods for forming the organic thin film include dry processes such as deposition (methods using the photoelectric conversion element material as is) and various solution processes (methods using a solution in which the photoelectric conversion element material is dissolved and / or dispersed in an organic solvent or the like). Examples of solution processes include letterpress printing methods such as spin coating, drop casting, dip coating, spraying, flexographic printing, and resin letterpress printing, lithographic printing methods such as offset printing, dry offset printing, and pad printing, intaglio printing methods such as gravure printing, stencil printing methods such as screen printing, mimeograph printing, and ring graph printing, inkjet printing, microcontact printing, and the like, as well as methods combining a plurality of these methods. When forming a film by a solution process, it is preferable to form a thin film by evaporating the solvent after carrying out the above-mentioned coating or printing.

[0029] Applicable The organic thin film has a low HOMO level energy that can suppress dark current when applied to a photoelectric conversion layer of an organic photoelectric conversion element. The HOMO level energy of the organic thin film can be calculated from the value of ionization potential using photoelectron spectroscopy. The HOMO level energy of the anthracene derivative represented by formula (1) and the organic thin film using the same is preferably -5.70 eV or less, more preferably -5.75 eV or less.

[0030] The organic thin film has electron transport properties or hole transport properties, and therefore can be used in organic semiconductor elements such as organic transistors and organic photoelectric conversion elements (organic thin film solar cells, photosensors, imaging elements, photocounters, LIDAR, etc.) by controlling the transport of electrons or holes injected from an electrode, or charges generated by absorbed light.

[0031] [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.

[0032] -Substrate 1- The substrate 1 is a member that supports the organic photoelectric conversion element 10. There are no particular limitations on the material of the substrate 1, and for example, substrates made of glass, transparent plastic, quartz, etc. can be used. In addition, when light is incident from the second electrode 6 side in FIG. 1, the substrate 1 does not necessarily have to be transparent. Here, "transparent" 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.

[0033] -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 they also need a function of allowing light to enter the photoelectric conversion layer 4, at least one of the first electrode 2 and the second electrode 6 needs to be transparent. There are no particular limitations on the material of the first electrode 2 and the second electrode 6 as long as it is conductive, but examples of the material include ITO, IZO, SnO 2 , ATO (antimony-doped tin oxide), ZnO, AZO (aluminum-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO 2Examples of the conductive material include conductive transparent materials such as ZnO 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 two or more of these materials as necessary, or may be a laminate of two or more layers.

[0034] -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.

[0035] The electron blocking layer 3 may contain a P-type organic semiconductor material that is a hole transporting material. As the P-type organic semiconductor material, a material for photoelectric conversion elements containing the anthracene derivative represented by the above formula (1) is preferable, but other P-type organic semiconductor materials may also be used.

[0036] 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, as well as aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0037] -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 an anthracene derivative represented by formula (1) is used as the P-type organic semiconductor material that is a hole transport material.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] -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.

[0042] 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. EXAMPLES

[0043] 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, "M" means molar concentration, and "%" means % by mass. The structures of the compounds described in the synthesis examples were determined by mass spectrometry (FAB-MS) and nuclear magnetic resonance spectrometry (NMR) as necessary. 1 H-NMR spectra were measured using an Avance400 or Avance500 (Bruker), FAB-MS spectra were measured using a JMS-700 (JEOL), and absorption spectra were measured using a UV-3600 (SHIMADZU).

[0044] [Example 1: Synthesis of compound (1-1)] (Step 1-1) Synthesis of an intermediate compound represented by the following formula (M1-1) Under a nitrogen atmosphere, 4-bromo-4'-iodobiphenyl (30.0 parts, 83.8 mmol), 3-thiopheneboronic acid (11.8 parts, 92.2 mmol) and potassium carbonate (57.8 parts, 419 mmol) were added to a mixture of toluene (215 mL), tetrahydrofuran (215 mL) and water (107 mL) and stirred. Tetrakistriphenylphosphine palladium (3.40 parts, 2.94 mmol) was added thereto, and the reaction solution was heated and stirred under reflux. After 6 hours, the reaction solution was cooled to room temperature, and the precipitated solid was collected by suction filtration. The solid was washed with water and ethanol and dried in a dryer to obtain a compound represented by formula (M1-1) (yield 23.0 parts, 86%) as a white solid. The mass spectrometry measurement results of the compound represented by formula (M1-1) were as follows. FAB-MS: m / z=315 [M+H] +

[0045] (Step 1-2) Synthesis of an intermediate compound represented by the following formula (M1-2) In a nitrogen atmosphere, the compound represented by formula (M1-1) obtained in step 1-1 (22.0 parts, 70.0 mmol), bis(pinacolato)diboron (21.4 parts, 84.0 mmol) and potassium acetate (16.5 parts, 168 mmol) were added to a 1,4-dioxane (350 mL) solution and stirred. [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2.86 parts, 3.50 mmol) was added thereto, and the reaction solution was heated to 100 ° C. After 8 hours, the reaction solution was cooled to room temperature, water and toluene were added, and the mixture was separated, and extracted with toluene. Anhydrous magnesium sulfate was added to the obtained organic layer to dry it, and after filtration, the organic solvent was distilled off by vacuum concentration. The obtained residue was purified by silica gel column chromatography (solvent: toluene) to obtain the compound represented by formula (M1-2) (yield 18.5 parts, yield 73%) as a white solid. The results of mass spectrometry of the compound represented by formula (M1-2) are shown below. FAB-MS: m / z=363 [M+H] +

[0046] (Step 1-3) Synthesis of compound (1-1) Under a nitrogen atmosphere, 2,6-dibromoanthracene (1.24 parts, 3.68 mmol), the compound represented by formula (M1-2) obtained in step 1-2 (3.20 parts, 8.84 mmol), and tripotassium phosphate (2.73 parts, 12.9 mmol) were added to DMF (200 parts) and stirred. Tetrakis(triphenylphosphine)palladium (0.213 parts, 0.184 mmol) was added thereto, and the reaction solution was heated to 90°C and stirred for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature, water was added, and the precipitated solid was collected by suction filtration. The obtained solid was washed with water and acetone and dried in a dryer. The obtained solid was further purified by vacuum sublimation to obtain compound (1-1) (1.78 parts, 75% yield) as a yellow crystalline solid.

[0047] [ka]

[0048] [Example 2: Synthesis of compound (1-2)] (Step 2-1) Synthesis of an intermediate compound represented by the following formula (M2-1) Under a nitrogen atmosphere, 6-bromo-2-naphthol (10.0 parts, 44.8 mmol), 3-thiopheneboronic acid (6.90 parts, 53.8 mmol), and sodium carbonate (14.2 parts, 134 mmol) were added to a mixed solution of toluene (120 mL), ethanol (80 mL), and water (40 mL), and the mixture was stirred. Tetrakistriphenylphosphine palladium (3.40 parts, 2.94 mmol) was added thereto, the temperature of the reaction solution was raised, and the mixture was stirred under reflux. After 6 hours, the reaction solution was cooled to room temperature, made acidic (pH = 2) by adding dilute hydrochloric acid to the reaction solution, and the precipitated solid was collected by suction filtration. The solid was washed with water and ethanol and dried in a dryer to obtain the compound represented by the formula (M2-1) (yield 7.53 parts, yield 74%) as a white solid. The measurement results of the mass spectrometry of the compound represented by the formula (M2-1) were as follows. FAB-MS: m / z = 227 [M + H] +

[0049] (Step 2-2) Synthesis of the intermediate compound represented by the following formula (M2-2) Under a nitrogen atmosphere, the compound represented by the formula (M2-1) (3.84 parts, 17.0 mmol) obtained in Step 2-1 and pyridine (2.74 mL, 34.0 mmol) were added to a dichloromethane (200 mL) solution, cooled to 0 °C in an ice bath, and stirred. Trifluoromethanesulfonic anhydride (5.75 parts, 20.4 mmol) was slowly added dropwise thereto, and the temperature of the reaction solution was raised to room temperature. After 3 hours, the reaction solution was treated with a saturated aqueous ammonium chloride solution and extracted with dichloromethane. Anhydrous magnesium sulfate was added to the obtained organic layer for drying, and after filtration, the organic solvent was distilled off by concentration under reduced pressure. The obtained residue was purified by silica gel column chromatography (solvent: toluene / hexane) to obtain the compound represented by the formula (M2-2) (yield 5.40 parts, yield 89%) as a white solid. The measurement results of the mass spectrometry of the compound represented by the formula (M2-2) were as follows. FAB-MS: m / z = 359 [M + H] +

[0050] (Step 2-3) Synthesis of the intermediate compound represented by the following formula (M2-3) The synthesis of the intermediate compound represented by formula (M2-3) was carried out in accordance with step 1-2, and the same operation was carried out except that the compound represented by formula (M2-2) obtained in step 2-2 (5.40 parts, 15.1 mmol) was used instead of the intermediate compound represented by formula (M1-1), and the intermediate compound represented by formula (M2-3) (yield 3.40 g, yield 67%) was obtained as a white solid. The mass spectrometry measurement results of the compound represented by formula (M2-3) were as follows. FAB-MS: m / z=493 [M+H] +

[0051] (Step 2-4) Synthesis of compound (1-2) Compound (1-2) was synthesized in the same manner as in step 1-3, except that the intermediate compound represented by formula (M1-2) was replaced by the compound represented by formula (M2-3) obtained in step 2-3. Compound (1-2) was synthesized as a yellow solid.

[0052] [ka]

[0053] [Comparative Examples 1 and 2 (Synthesis of Comparative Compounds (2-1) and (2-2)] Comparative compounds (2-1) and (2-2) were synthesized by known methods.

[0054] [ka]

[0055] (Measurement of HOMO level energy of organic thin films) Each of the organic compounds obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was subjected to resistance heating vacuum deposition on a pre-cleaned glass substrate to prepare an organic thin film (thickness 100 nm) of each compound. Using each of the obtained organic thin films as samples, the HOMO level energy of each organic compound in a thin film state was determined by photoelectron spectroscopy (AC-3, manufactured by Riken Keiki Co., Ltd.). The HOMO level energy of the organic thin film of each compound is shown in Table 1.

[0056] [Table 1]

[0057] From these results, it can be said that the organic thin film prepared using the compound of the present invention has a lower HOMO level energy than the organic thin film prepared using each comparative compound, and is significant in suppressing dark current when used in a photoelectric conversion element. Below, photoelectric conversion elements were actually prepared and examined.

[0058] [Example 3: Preparation of photoelectric conversion element A] A blocking layer was formed on a glass substrate with an ITO electrode having a thickness of 70 nm. The substrate temperature was room temperature and the vacuum degree was 4.0×10 -5 A film of CzBDF (manufactured by Tokyo Chemical Industry Co., Ltd.) was formed to a thickness of 10 nm under the condition of 20 Pa. Then, the compound (1-1) obtained in Example 1, Cl 6 -SubPc-OPh (manufactured by Lumitec) 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 with 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 produce photoelectric conversion element A.

[0059] [ka]

[0060] [Example 4: Preparation of photoelectric conversion element B] A photoelectric conversion element B was prepared in the same manner as in Example 3, except that the compound (1-2) obtained in Example 2 was used instead of the compound (1-1).

[0061] [Comparative Examples 4 and 5: Preparation of Photoelectric Conversion Elements P and Q] Comparative photoelectric conversion elements P and Q were prepared by the same procedure as in Example 3, except that comparative compound (2-1) and comparative compound (2-2), respectively, were used instead of the compound represented by compound (1-1).

[0062] (Evaluation of organic photoelectric conversion element) The photoelectric conversion elements were evaluated based on the examples in WO2018-105269. Specifically, the photoelectric conversion elements A, B, and P to R were each subjected to a 2.0×10 5 A voltage was applied to the sample to obtain an intensity of 1000 V / cm, and the EQE and dark current of the photoelectric conversion at 550 nm were measured. The results are shown in Table 2. Evaluation criteria If EQE is 85% or more, mark as "○". If less than 85%, mark "X". Dark current 5.0×10 -11 A / cm 2 If less than: "○" 5.0×10 -11 Above 1.0×10 -10 A / cm 2 If less than: "△" 1.0×10 -10 A / cm 2 If above, "×" In practice, the larger the EQE, the more efficiently the irradiated light can be converted into electrical energy, so an "O" indicates superiority and an "X" indicates inferiority. The smaller the dark current, the more the current value can be suppressed when the light irradiation is off, so an "O" indicates superiority and an "X" indicates inferiority.

[0063] [Table 2]

[0064] From the results in Table 2, it can be seen that the photoelectric conversion element made using the anthracene derivative of the present invention can suppress the dark current more than the photoelectric conversion element made using each comparative compound. In combination with the results in Table 1, it can be seen that the HOMO level energy of the anthracene derivative is important for suppressing the dark current, being lower than -5.70 eV.

[0065] (Response speed evaluation) The response was evaluated based on the example of WO2018-105269. Specifically, 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 (ITO) 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 the element of Comparative Example 4 was taken as 1. The results are shown in Table 3. Evaluation criteria The relative value of the rise time is compared with Comparative Example 3. If less than 0.1, select "AA" If it is 0.1 or more but less than 0.2, then "A" If it is 0.2 or more but less than 0.4, it is "B" If it is 0.4 or more but less than 0.6, it is "C" If it is 0.6 or more, it is "D". In practice, it is desirable for the photoelectric conversion element to have a fast photoresponse speed, i.e., for the photocurrent value to approach 100% in a short time after exposure to light, so "A" means the best and "D" means the worst.

[0066] [Table 3]

[0067] The results in Table 3 show that the photoelectric conversion elements of Examples 1 and 2 exhibited good EQE and dark current values, and also had excellent response speeds. Combined with the results in Table 1, it can be seen that the HOMO level energy of the anthracene derivative being -5.70 eV or less is important for improving the response speed. [Industrial Applicability]

[0068] By using the anthracene derivative represented by formula (1), it is possible to provide an organic semiconductor device (photoelectric conversion element, optical sensor) that exhibits a high EQE, a low dark current value, and an excellent response speed. [Explanation of symbols]

[0069] 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 formula (1), X and Y each independently represent a divalent aromatic hydrocarbon group, a divalent heterocyclic group, or a single bond, except for the case where both X and Y are single bonds.) An anthracene derivative represented by the formula:

2. 2. The anthracene derivative according to claim 1, wherein X and Y are the same.

3. The anthracene derivative according to claim 1, wherein X and Y are different from each other.

4. 2. The anthracene derivative according to claim 1, wherein X and Y each independently represent a divalent aromatic hydrocarbon group.

5. 2. The anthracene derivative according to claim 1, wherein the HOMO energy level is −5.70 eV or less.

6. An organic semiconductor material comprising the anthracene derivative according to claim 1.

7. A material for a photoelectric conversion element, comprising the anthracene derivative according to claim 1 .

8. An organic thin film comprising the anthracene derivative according to claim 1, the organic semiconductor material according to claim 6, or the material for a photoelectric conversion device according to claim 7.

9. An organic photoelectric conversion element comprising the organic thin film according to claim 8 .

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