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

Abstract

To provide a condensed polycyclic aromatic compound that simultaneously exhibits enhanced external quantum efficiency (EQE) and suppressed dark current characteristics, when used as a hole-transport material in an organic photoelectric conversion element.SOLUTION: Provided is a condensed polycyclic aromatic compound represented by the following formula (1). (In the formula, R1 to R10 each independently represent a hydrogen atom, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, or a halogen atom).SELECTED DRAWING: None

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 novel compound having a fused polycyclic aromatic skeleton, an organic semiconductor material containing the compound, a material for an organic photoelectric conversion element, an organic thin film, and an organic photoelectric conversion element having 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. 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 imaging elements, for example, is being considered (Patent Document 1). When using an organic photoelectric conversion element as an imaging element, 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.

[0004] In order to satisfy such required characteristics, in recent years, bulk heterojunction structures have been researched for organic photoelectric conversion elements as photoelectric conversion layers, which are made of mixed films of organic dyes that selectively absorb light in a wavelength direction, hole transport materials (P-type organic semiconductors), and electron transport materials (N-type organic semiconductors) (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2022 / 114065 [Patent Document 2] WO2016 / 185858 [Patent Document 3] WO2018 / 016465 [Patent Document 4] WO2017 / 014146 Summary of the Invention [Problem to be solved by the invention]

[0006] However, few of the photoelectric conversion elements reported so far have been able to simultaneously satisfy both EQE and dark current characteristics. Patent documents 3 and 4 describe that by using a benzothieno[3,2-b][1]benzothiophene (hereinafter abbreviated as "BTBT") derivative as a hole transport material in a photoelectric conversion element, both a high EQE and a low dark current can be achieved, but further improvement is essential for practical use.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a fused polycyclic aromatic compound that can achieve both excellent external quantum efficiency (EQE) and dark current characteristics when used as a hole transport material in a photoelectric conversion element, as well as an organic semiconductor material, a material for an organic photoelectric conversion element, an organic thin film, and an organic photoelectric conversion element each using the same. [Means for solving the problem]

[0008] As a result of intensive research, the inventors have found that by using a novel condensed polycyclic aromatic compound as a hole transport material in an organic photoelectric conversion element, an excellent organic photoelectric conversion element capable of achieving both external quantum efficiency and dark current characteristics can be obtained, and have completed the present invention.

[0009] That is, the present invention relates to the following [1] to [5]. [1] General formula (1) [ka] (In the formula, R 1 From R 10each independently represents a hydrogen atom, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, or a halogen atom. A condensed polycyclic aromatic compound represented by the formula: [2]R 3 and R 7 at least one of which is a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, or a halogen atom. [3] R 3 and R 7 At least one of the above is a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group. [4]R 1 , R 2 , R 4 , R 5 , R 6 , R 8 , R 9 , and R 10 The condensed polycyclic aromatic compound according to any one of the above [1] to [3], wherein [5] An organic semiconductor material comprising the condensed polycyclic aromatic compound according to [1] above. [6] A material for an organic photoelectric conversion element, comprising the fused polycyclic aromatic compound according to [1] above. [7] An organic thin film comprising the condensed polycyclic aromatic compound according to [1] above. [8] An organic photoelectric conversion element comprising the organic thin film described in [7] above. Effect of the Invention

[0010] The present invention can provide a fused polycyclic aromatic compound that can achieve both excellent external quantum efficiency (EQE) and dark current characteristics when used as a hole transport material in a photoelectric conversion element, as well as an organic semiconductor material, a material for an organic photoelectric conversion element, an organic thin film, and an organic photoelectric conversion element using the same. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of an organic photoelectric conversion element according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 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.

[0013] [Fused polycyclic aromatic compound] The condensed polycyclic aromatic compound of the present invention is represented by the following general formula (1). [ka]

[0014] In formula (1), R 1 from 10 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, and a halogen atom.

[0015] The aryl group is a residue obtained by removing one hydrogen atom from the aromatic ring of an aromatic hydrocarbon compound, and specific examples thereof include a phenyl group, a biphenyl group, a terphenyl group, a tolyl group, an indenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, a phenanthenyl group, and a mestil group. As the aromatic hydrocarbon group, a phenyl group, a biphenyl group, a terphenyl group, a tolyl group, and a naphthyl group are preferred, and a phenyl group, a biphenyl group, and a naphthyl group are more preferred. The substituent that the aryl group may have is not particularly limited, and a heterocyclic group, an alkyl group, an alkynyl group, an alkoxy group, and a halogen atom are preferred, and a heterocyclic group and an alkyl group are more preferred. Specific examples of the heterocyclic group, the alkyl group, the alkynyl group, the alkoxy group, and the halogen atom include R 1 from 10 The same things as those mentioned above can be mentioned.

[0016] The heterocyclic group is a residue obtained by removing one hydrogen atom from a heterocyclic ring of a heterocyclic compound, and specific examples thereof include a furanyl group, a thienyl group, a thienothienyl group, a pyrrolyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, a pyridyl group, a pyrazyl group, a pyrimidyl group, an indolyl group, a benzopyrazyl group, a benzopyrimidyl group, a benzofuranyl group, a benzothienyl group, a benzothiazolyl group, a pyridinothiazolyl group, a benzimidazolyl group, a pyridinoimidazolyl group, a benzoxazolyl group, a pyridinooxazolyl group, a benzothiadiazolyl group, a pyridinothiadiazolyl group, a benzoxadiazolyl group, a pyridinooxadiazolyl group, a carbazolyl group, a phenoxazinyl group, and a phenothiazinyl group. As the heterocyclic group, a furanyl group, a thienyl group, a thienothienyl group, a pyridyl group, a benzofuranyl group, and a benzothienyl group are preferred, and a thienyl group, a pyridyl group, and a benzothienyl group are more preferred. The substituent that the heterocyclic group may have is not particularly limited, but an aryl group, a heterocyclic group, an alkyl group, an alkynyl group, an alkoxy group, and a halogen atom are preferred, and an aryl group, a heterocyclic group, and an alkyl group are more preferred. Specific examples of the aryl group, the heterocyclic group, the alkyl group, the alkynyl group, the alkoxy group, and the halogen atom include R 1 from10 The same things as those mentioned above can be mentioned.

[0017] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-cetyl group, an n-heptadecyl group, a 2-ethylhexyl group, a 3-ethylheptyl group, a 4-ethyloctyl group, a 2-butyloctyl group, a 3-butylnonyl group, a 4-butyldecyl group, a 2-hexyldecyl group, a 3-octylundecyl group, a 4-octyldodecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, stomach Preferred are isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, cyclohexyl or 2-ethylhexyl, and more preferred are methyl, ethyl, n-propyl, n-butyl, hexyl or 2-ethylhexyl. The substituent that the alkyl group may have is not particularly limited, and is preferably an aryl group, a heterocyclic group, an alkynyl group, an alkenyl group, an alkoxy group or a halogen atom, and more preferably an aryl group, a heterocyclic group or a halogen atom. Specific examples of the aryl group, the heterocyclic group, the alkynyl group, the alkenyl group, the alkoxy group or the halogen atom include R 1 from 10 The same things as those mentioned above can be mentioned.

[0018] The alkenyl group is a linear, branched or cyclic alkenyl group. The number of carbon atoms in the alkenyl group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10. Examples of the alkenyl group include a substituent in which one or more saturated carbon-carbon bonds in the substituents exemplified above as the alkyl group are replaced with unsaturated carbon-carbon double bonds. The alkenyl group is preferably a vinyl group, an allyl group, a prenyl group, an isoprenyl group, a butenyl group, an isobutenyl group, or a cyclohexenyl group, and more preferably a vinyl group, a prenyl group, an isoprenyl group, or a cyclohexenyl group. The substituent that the alkenyl group may have is not particularly limited, and is preferably an aryl group, a heterocyclic group, an alkyl group, an alkoxy group, or a halogen atom, and more preferably an aryl group or a heterocyclic group. Specific examples of the aryl group, the heterocyclic group, the alkyl group, the alkoxy group, and the halogen atom include R 1 from 10 The same things as those mentioned above can be mentioned.

[0019] The alkynyl group is a linear, branched or cyclic alkynyl group, and the number of carbon atoms is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10. Examples of the alkynyl group include a substituent in which one or more saturated carbon-carbon bonds of the substituents exemplified above as the alkyl group are replaced with unsaturated carbon-carbon triple bonds. The alkynyl group is preferably an ethynyl group, a propargyl group, an ethynylphenyl group, a butynyl group, or a pentynyl group, and more preferably an ethynyl group, a propargyl group, or an ethynylphenyl group. The substituent that the alkynyl group may have is not particularly limited, and is preferably an aryl group, a heterocyclic group, an alkyl group, an alkoxy group, or a halogen atom, and more preferably an aryl group or a heterocyclic group. Specific examples of the aryl group, the heterocyclic group, the alkyl group, the alkoxy group, and the halogen atom include R 1 from 10 The same things as those mentioned above can be mentioned.

[0020] The alkoxy group is an alkoxy group having a linear, branched, or cyclic alkyl group, and the number of carbon atoms is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10. Examples of the alkoxy group include those in which the substituents exemplified above as the alkyl group form a bond via an oxygen atom. The alkoxy group is preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a t-butoxy group, an n-pentyloxy group, an n-hexyloxy group, a cyclohexyloxy group, or a 2-ethylhexyloxy group, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an n-butyl group, a hexyloxy group, or an ethylhexyloxy group. The substituent that the alkoxy group may have is not particularly limited, but is preferably an aryl group, a heterocyclic group, an alkoxy group, and a halogen atom, and more preferably an aryl group and a heterocyclic group. Specific examples of the aryl group, the heterocyclic group, the alkoxy group, and the halogen atom include R 1 from 10 The same things as those mentioned above can be mentioned.

[0021] The halogen atom specifically represents fluorine, chlorine, bromine or iodine.

[0022] R 1 , R 2 , R 4 , R 5 , R 6 , R 8 , R 9 , and R 10 is preferably a hydrogen atom. 3 and R 7 At least one of the is preferably selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, and a halogen atom, and is more preferably a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group.

[0023] Next, a method for synthesizing the condensed polycyclic aromatic compound represented by the general formula (1) will be described. The condensed polycyclic aromatic compound represented by the general formula (1) can be synthesized by the method shown in the following scheme as an example, but is not limited to this method. 1 ~R 10 Depending on the type of the material, other methods may be used as appropriate.

[0024] The condensed polycyclic aromatic compound represented by the general formula (1) is prepared by brominating two positions of substituted or unsubstituted 1,4-difluorobenzene (A) as a starting material to synthesize a dibromo compound (B), which is then subjected to an electrophilic substitution reaction with methyl mercaptan to obtain an intermediate compound (C). This compound (C) can be converted to a bissulfinyl compound (D) by oxidizing the sulfide group using hydrogen peroxide or an organic peroxide. Compound (D) can be converted to a coupling product (E) by subjecting substituted or unsubstituted 2-benzothiopheneboronic acid to Suzuki-Miyaura coupling conditions, and then converted to a coupling product (F) by subjecting substituted or unsubstituted phenylboronic acid to the same Suzuki-Miyaura coupling conditions. Finally, the obtained compound (F) can be reacted with a strong acid or anhydride of a strong acid and treated with pyridine to synthesize an alkoxy intermediate (G). Intermediate (G) can be converted to intermediate (H) by deprotecting the methyl group and then triflating it, and then the substituent R 3 The fused polycyclic aromatic compound represented by the general formula (1) can be synthesized by introducing the boronic acid derivative of the above by a coupling reaction.

[0025] [ka]

[0026] R in formula (A) to formula (H) 1 From R 10 is R in formula (1). 1 From R 10 It has the same meaning as:

[0027] Specific examples of the condensed polycyclic aromatic compound represented by the general formula (1) are shown below, but the compound is not limited to these specific examples.

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [ka] TIFF2025059659000009.tif112168

[0033] [Organic semiconductor materials (hole transport materials)] The organic semiconductor material contains a condensed polycyclic aromatic compound 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. The organic semiconductor material may contain one or more types of fused polycyclic aromatic compounds represented by formula (1). The organic semiconductor material containing the fused polycyclic aromatic compound represented by formula (1) 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, and an organic photoelectric conversion element. For example, by using the organic semiconductor material as a hole transport material for an organic photoelectric conversion element (hereinafter also referred to as "material for organic photoelectric conversion element"), an organic photoelectric conversion element having both excellent external quantum efficiency (EQE) and dark current characteristics can be realized.

[0034] [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 (methods using the organic semiconductor material as is) such as deposition methods, and various solution processes (methods using a solution in which the organic semiconductor material is dissolved and / or dispersed in an organic solvent, etc.). 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 evaporate the solvent after carrying out the above-mentioned coating or printing to form a thin film.

[0035] The organic thin film of the present invention 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.

[0036] [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 (upper electrode) 2, an electron blocking layer 3, a photoelectric conversion layer 4, a hole blocking layer 5, and a second electrode (lower 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 material for organic photoelectric conversion elements 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.

[0037] -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.

[0038] -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.

[0039] -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.

[0040] 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 an organic photoelectric conversion element containing a condensed polycyclic aromatic compound represented by the above formula (1) is preferable, but other P-type organic semiconductor materials may also be used.

[0041] Examples of other P-type organic semiconductor materials that can be used include 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-excess heterocyclic aromatic group, such as 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; and nitrogen-containing electron donor compounds, such as aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0042] -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, or may be formed in combination with one or both of a P-type organic semiconductor material, which is a hole transport material, and an N-type organic semiconductor material, which 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, an organic semiconductor material containing a condensed polycyclic aromatic compound represented by formula (1) is used as the P-type organic semiconductor material, which is a hole transport material.

[0043] 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.

[0044] When the above organic semiconductor materials are used as the P-type organic semiconductor material, they may be used in combination with other P-type organic semiconductor materials, or two or more of the above organic semiconductor materials 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 organic semiconductor 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.

[0045] 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.

[0046] -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. EXAMPLES

[0047] 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 (EI-MS) and nuclear magnetic resonance spectrometry (NMR) as necessary. 1H-NMR spectra were measured using Avance400 or Avance500 (Bruker), and EI-MS was measured using ISQ7000 (Thermo Scientific).

[0048] [Synthesis Example 1: Synthesis of Compound No. 23] Compound No. 23 was synthesized by the following procedure: 1,4-dibromo-2,5-bis(methylsulfinyl)benzene, which is the starting material, was synthesized by using the method described in a publicly known document (Macromolecules 1999, 32, 9, 3146-3149.).

[0049] (Step 1-1) Synthesis of an intermediate compound represented by the following formula (M1-1) Under a nitrogen atmosphere, 1,4-dibromo-2,5-bis(methylsulfinyl)benzene (5.02 parts, 13.9 mmol), 4-biphenylboronic acid (2.75 parts, 13.9 mmol), 2M aqueous sodium carbonate solution (15 mL), and tetrakis(triphenylphosphine)palladium (0.482 parts, 0.417 mmol) were added to toluene (60 mL) and stirred at reflux temperature for 2 hours. The resulting reaction solution was cooled to room temperature and subjected to liquid separation and extraction using toluene. The resulting organic layer was dried over magnesium sulfate, and the filtrate obtained by filtration was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (mobile phase: dichloromethane) to obtain an intermediate compound represented by the following formula (M1-1) (3.61 parts, yield 60%) as a light yellow solid.

[0050] (Step 1-2) Synthesis of an intermediate compound represented by the following formula (M1-2) Under a nitrogen atmosphere, the intermediate compound (3.45 parts, 7.97 mmol) represented by formula (M1-1) obtained in step 1-1, (6-methoxybenzo[b]thiophen-2-yl)boronic acid (2.48 parts, 12.0 mmol), 2M aqueous sodium carbonate solution (12 mL), and tetrakis(triphenylphosphine)palladium (0.276 parts, 0.239 mmol) were added to toluene (40 mL) and stirred at reflux temperature for 3 hours. The reaction solution obtained was cooled to room temperature and subjected to liquid separation and extraction using toluene. The organic layer obtained was dried over magnesium sulfate, and the filtrate obtained by filtration was concentrated under reduced pressure. The residue obtained was purified by silica gel column chromatography (mobile phase: dichloromethane) to obtain the intermediate compound (3.74 parts, 91% yield) represented by the following formula (M1-2) as a yellow solid.

[0051] (Step 1-3) Synthesis of an intermediate compound represented by the following formula (M1-3) Under a nitrogen atmosphere, the intermediate compound (3.20 parts, 6.19 mmol) represented by formula (M1-2) obtained in step 1-2 was added to dichloromethane (40 mL), cooled to 0 ° C., and stirred. Trifluoromethanesulfonic anhydride (3.72 parts, 13.2 mmol) was added dropwise thereto, and the temperature was raised to room temperature. After stirring for 12 hours, the reaction solution was cooled again to 0 ° C., and pyridine (120 mL) and water (40 mL) were slowly added. Then, the reaction solution was heated to 70 ° C. and stirred for 1 hour. The obtained reaction solution was cooled to room temperature, and the precipitated solid was collected by suction filtration. The obtained solid was washed with water and acetone to obtain the intermediate compound (2.46 parts, 88% yield) represented by the following formula (M1-3) as a yellow solid.

[0052] (Step 1-4) Synthesis of an intermediate compound represented by the following formula (M1-4) Under a nitrogen atmosphere, the intermediate compound (2.21 parts, 4.89 mmol) represented by formula (M1-3) obtained in step 1-3 was added to dichloromethane (50 mL), cooled to 0 ° C., and stirred. A 1 M dichloromethane solution of boron tribromide (7.33 mL, 7.33 mmol) was added dropwise thereto, and the mixture was warmed to room temperature and reacted for 24 hours. After the reaction was completed, the reaction solution was quenched by adding saturated sodium bicarbonate, and the organic solvent was distilled off under reduced pressure. The precipitated solid was then collected by suction filtration and washed with water and methanol to obtain the intermediate compound (1.95 parts, 91% yield) represented by the following formula (M1-4) as a yellow solid.

[0053] (Step 1-5) Synthesis of an intermediate compound represented by the following formula (M1-5) Under a nitrogen atmosphere, the intermediate compound (1.67 parts, 3.81 mmol) represented by formula (M1-4) obtained in step 1-4 was added to a mixed solution of dichloromethane (50 mL) and pyridine (20 mL) and stirred. Trifluoromethanesulfonic anhydride (1.29 parts, 4.57 mmol) was added dropwise thereto and stirred for 1 hour. After the reaction was completed, the obtained reaction solution was poured into water (300 mL) and the resulting solid was collected by suction filtration. The obtained solid was washed with water and methanol to obtain the intermediate compound (2.15 parts, 99% yield) represented by the following formula (M1-5) as a yellow solid.

[0054] (Step 1-6) Synthesis of the compound represented by specific example No. 23 Under a nitrogen atmosphere, in DMF (45 mL), the intermediate compound represented by formula (M1-5) obtained in step 1-5 (1.04 parts, 1.82 mmol), 2-(4'-(benzo[b]thiophen-5-yl)-[1,1'-biphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.902 parts, 2.19 mmol), potassium triphosphate (0.772 parts, 3.64 mmol), and tetrakis(triphenylphosphine)palladium (0.105 parts, 0.091 mmol) were added and stirred at reflux temperature for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into water (200 mL). The precipitated solid was collected by suction filtration and washed with acetone. Finally, the solid obtained was purified by vacuum sublimation to obtain Compound No. 23 (0.631 parts, 55% yield) as a yellow crystalline solid. The results of EI-MS measurement of Compound No. 23 were as follows. EI-MS m / z: Calcd for C 46 H 26 S4[M + ]: 707 Found: 707.

[0055] [ka]

[0056] [Synthesis Example 2: Synthesis of Compound No. 24] Compound No. 24 was synthesized by the following procedure. The intermediate compound represented by the following formula (M2-1) can be synthesized by the same method as the synthesis method of intermediate (M1-5) in Synthesis Example 1, and was synthesized by carrying out the same operations as in steps 1-1 to 1-5, except that 4-(4-biphenyl)phenylboronic acid was used instead of 4-biphenylboronic acid in step 1-1.

[0057] (Step 2-1) Synthesis of Compound No. 24 Under a nitrogen atmosphere, an intermediate compound represented by the following formula (M2-1) (0.740 parts, 1.15 mmol), 2-(4-(benzo[b]thiophen-5-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.403 parts, 1.20 mmol), potassium triphosphate (0.509 parts, 2.40 mmol), and tetrakis(triphenylphosphine)palladium (0.066 parts, 0.0575 mmol) were added to DMF (30 mL) and stirred at reflux temperature for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into water (150 mL). The precipitated solid was collected by suction filtration and washed with DMF. Finally, the obtained solid was purified by vacuum sublimation to obtain compound No. 24 (0.455 parts, yield 56%). The results of EI-MS measurement of the obtained compound No. 24 are as follows: EI-MS m / z: Calcd for C 46 H 26 S4[M + ]: 707 Found: 707.

[0058] [ka]

[0059] [Synthesis Example 3: Synthesis of Compound No. 28] Compound No. 28 was synthesized by the following procedure. The intermediate compound represented by the following formula (M3-1) can be synthesized by the same method as the synthesis method of the intermediate (M1-5) in Synthesis Example 1, and can be synthesized by carrying out the same operations as in steps 1-1 to 1-5, except that phenylboronic acid is used instead of 4-biphenylboronic acid in step 1-1.

[0060] (Step 3-1) Synthesis of Compound No. 28 Under a nitrogen atmosphere, in DMF (50 mL), the intermediate compound represented by the following formula (M3-1) (1.12 parts, 2.27 mmol), 2-(4''-(benzo[b]thiophen-5-yl)-[1,1':4',1''-terphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.14 parts, 2.34 mmol), potassium triphosphate (0.962 parts, 4.54 mmol), and tetrakis(triphenylphosphine)palladium (0.131 parts, 0.114 mmol) were added to DMF (50 mL) and stirred at reflux temperature for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into water (250 mL). The precipitated solid was collected by suction filtration and washed with DMF. Finally, the obtained solid was purified by vacuum sublimation to obtain Compound No. 28 (1.00 part, yield 63%). The results of EI-MS measurement of the obtained Compound No. 28 were as follows. EI-MS m / z: Calcd for C 46 H 26 S4[M + ]: 707 Found: 707.

[0061] [ka]

[0062] [Synthesis Example 4: Synthesis of Compound No. 27] (Step 4-1) Synthesis of Compound No. 27 Compound No. 27 was synthesized by the same procedure as in Synthesis Example 3, except that 2-(4-(benzo[b]thiophen-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane synthesized with reference to the method described in WO2018 / 01646 was used instead of 2-(4''-(benzo[b]thiophen-5-yl)-[1,1':4',1''-terphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in step 3-1, and compound No. 27 (0.812 parts, yield 51%) was obtained. The results of EI-MS measurement of the obtained compound No. 27 were as follows. EI-MS m / z: Calcd for C 46 H 26 S4[M + ]: 707 Found: 707.

[0063] [ka]

[0064] [Comparative Synthesis Examples 1 to 3 (Synthesis of Comparative Compounds 1 to 3)] Comparative Compound 1, Comparative Compound 2, and Comparative Compound 3 were synthesized using known methods.

[0065] [ka]

[0066] [Example 1: 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 -5Under conditions of 10 Pa, CzBDF (manufactured by Tokyo Chemical Industry Co., Ltd.) was deposited to a thickness of 10 nm. Next, as a photoelectric conversion layer, Compound No. 23 obtained in Synthesis Example 1, Cl6-SubPc-OPh (manufactured by Lumitec Co., Ltd.) and fullerene (C60, manufactured by Tokyo Chemical Industry Co., Ltd.) were co-deposited 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 deposited 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.

[0067] [ka]

[0068] [Examples 2 to 4: Preparation of organic photoelectric conversion elements B to D] Organic photoelectric conversion elements B to D were produced in the same manner as in Example 1, except that compound No. 24, compound No. 28 and compound No. 27 obtained in Synthesis Examples 2 to 4 were used instead of compound No. 23.

[0069] [Comparative Examples 1 to 3: Preparation of organic photoelectric conversion elements P to R] Comparative organic photoelectric conversion elements P to R were prepared in the same manner as in Example 1, except that comparative compound 1, comparative compound 2 and comparative compound 3 were used instead of compound No. 23.

[0070] (Evaluation of organic photoelectric conversion element) The organic photoelectric conversion elements were evaluated based on the examples in WO2018-105269. Specifically, the organic photoelectric conversion elements A to D and P to R were each subjected to a 1.0×10 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 1.

[0071] Evaluation criteria EQE 90% or more: "AA" If it is 85% or more but less than 90%, then it is "A". If it is 80% or more but less than 85%, it is "B" If less than 80%, "C" Dark current 5.0×10 -11 A / cm 2 If less than: "A" 5.0×10 -11 Above 1.0×10 -10 A / cm 2 If less than: "B" 1.0×10 -10 A / cm 2 If above: "C" In practice, the larger the EQE, the more efficiently the irradiated light is converted into electrical energy, meaning that "AA" is the best and "C" is the worst. The smaller the dark current, the more the current value can be suppressed when the light irradiation is off, meaning that "A" is the best and "C" is the worst.

[0072] [Table 1]

[0073] From the results in Table 1, the organic photoelectric conversion elements using the compounds of Examples 1 to 4 exhibited good EQE and dark current values. It was found that all the organic photoelectric conversion elements of Examples 1 to 4 exhibited a higher EQE than the organic photoelectric conversion element of Comparative Example 3. In addition, all the organic photoelectric conversion elements of Examples 1 to 4 exhibited better dark current characteristics than the organic photoelectric conversion elements of Comparative Example 1 and Comparative Example 2. From the above results, it is found that an organic photoelectric conversion element using the fused polycyclic aromatic compound represented by formula (1) of the present invention has both excellent EQE and dark current characteristics, and therefore can be suitably used for an organic photoelectric conversion element and an organic imaging element. [Explanation of symbols]

[0074] 1 Board 2 First electrode (upper electrode) 3. Electron Block Layer 4 Photoelectric conversion layer 5 Hole Blocking Layer 6 Second electrode (lower electrode) 10 Organic photoelectric conversion element

Claims

1. General formula (1) 【Chemistry 1】 (In the formula, R １ From R １０ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, or a halogen atom. A condensed polycyclic aromatic compound represented by the formula:

2. R ３ and R ７ 2. The condensed polycyclic aromatic compound according to claim 1, wherein at least one of the groups is a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, or a halogen atom.

3. R ３ and R ７ The condensed polycyclic aromatic compound according to claim 1 , wherein at least one of the groups is a substituted or unsubstituted aryl group.

4. R １ , R ２ , R ４ , R ５ , R ６ , R ８ , R ９ , and R １０ The condensed polycyclic aromatic compound according to any one of claims 1 to 3, wherein

5. An organic semiconductor material comprising the condensed polycyclic aromatic compound according to claim 1.

6. A material for an organic photoelectric conversion element, comprising the condensed polycyclic aromatic compound according to claim 1 .

7. An organic thin film comprising the condensed polycyclic aromatic compound according to claim 1 .

8. An organic photoelectric conversion element comprising the organic thin film according to claim 7 .

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