Photoelectric converter, image sensor, fingerprint sensor, and pulse wave sensor

Abstract

To provide a photoelectric converter including a chemical compound useful especially as a p-type semiconductor material which has high sensitivity to green light and is carefully designed with a tuned absorption wavelength.SOLUTION: A photoelectric converter includes a chemical compound represented by A=CH-L-D, D being a group formed by combining one or two selected from a monocyclic or bicyclic fused ring aryl group or heteroaryl group, in which the heteroaryl ring is bonded to L. L is a thiophene ring or a thienothiophene ring, which may have a substituent. A is a group represented by a formula (2) (where Z is a benzene ring or a naphthalene ring, which may have a substituent, and X is an oxygen atom or a dicyanomethylene group). [Formula 1].SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element, an image sensor, a fingerprint sensor, and a pulse wave sensor. [Background technology]

[0002] As we enter the era of digital transformation, there are increasing opportunities to use sensors to obtain data necessary for big data analysis, customization proposals, and more. Photoelectric conversion elements, as sensors capable of converting light into electricity, are used in image sensors, fingerprint sensors, pulse wave sensors, etc. For this reason, photoelectric conversion elements are beginning to be incorporated into various devices, and there is an increasing need for sensors that are highly sensitive to specific light, such as the RGB light source of LED lighting.

[0003] Against this background, in order to make photoelectric conversion elements suitable for incorporation into a variety of devices, a new lineup of materials contained within the elements (p-type semiconductor materials, n-type semiconductor materials, hole transport materials, electron transport materials, etc.) is required. When the p-type semiconductor material in the photoelectric conversion layer absorbs light in addition to transporting holes, it is known that the material has a structure in which an electron-donating moiety and a potential-withdrawing moiety are linked in order to improve light absorption (e.g., Patent Document 1 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 038064 [Non-patent literature]

[0005] [Non-Patent Document 1] J. Mater. Chem. C, 2016, 4, 1117 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional p-type semiconductor materials have insufficient sensitivity to green light. A primary object of the present invention is to provide a photoelectric conversion element containing a compound which is particularly useful as a p-type semiconductor material having high sensitivity to green light and a precisely designed absorption wavelength, and to provide an image sensor, a fingerprint sensor and a pulse wave sensor which use the photoelectric conversion element. [Means for solving the problem]

[0007] The present inventors have conducted studies in light of the above-mentioned problems and have found that a compound in which a monocyclic or bifused aryl or heteroaryl group, or a group in which two of them are linked, is connected to an electron-donating moiety and an electron-withdrawing moiety bonded to a thiophene ring or thienothiophene ring, is effective as a p-type semiconductor material highly sensitive to green light, which has led to the completion of the present invention.

[0008] That is, the present invention includes the following configurations. [1] A photoelectric conversion element comprising a compound represented by the following general formula (1):

[0009] [ka]

[0010] (In the formula (1), D is a group formed by combining one or two selected from a monocyclic heteroaryl group, a fused-ring heteroaryl group consisting of two fused rings, a monocyclic aryl group, and a fused-ring aryl group consisting of two fused rings, and contains at least a heteroaryl ring, and the heteroaryl ring is always bonded to L. L is a thiophene ring in which one or more hydrogen atoms may be substituted, or a thienothiophene ring in which one or more hydrogen atoms may be substituted. A is a group represented by the following general formula (2). A group represented by A=CH- and D are bonded to the thiophene ring or the thienothiophene ring of L.)

[0011] [ka]

[0012] (In the formula (2), Z is a benzene ring or a naphthalene ring in which one or more hydrogen atoms may be substituted. X is an oxygen atom or a dicyanomethylene group.) [2] The photoelectric conversion element according to [1], wherein D is any one of groups represented by the following general formulas (3a) to (3e):

[0013] [ka]

[0014] (In the above formula, Y 1 , Y 3 , Y 7 , Y 9 and Y 12 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or NZ 3 Y 2 , Y 4 , Y 6 , Y 8 , Y 10 , Y 11 and Y 13 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ 1 =CZ 2 Y 5 and Y 14 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ 1 =CZ 2 or NZ 3 It is. 1 and Z 2 are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group. 3 is an alkyl group or an aryl group. [3] The photoelectric conversion element according to [1] or [2], wherein A is a group represented by the following general formula (2a) or (2b):

[0015] [ka]

[0016] (In the formulas (2a) and (2b), Q 1 ~Q 8 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group. 1 and X 2 are each independently an oxygen atom or a dicyanomethylene group. [4] The photoelectric conversion element according to any one of [1] to [3], wherein the compound represented by formula (1) includes at least one of a compound represented by the following general formula (1a) and a compound represented by the following general formula (1b):

[0017] [ka]

[0018] (In the above formula, R 1 and R 2 are each independently a hydrogen atom, a deuterium atom, an alkyl group, C(=O)OR (wherein R is an alkyl group or an aryl group), or an amino group. [5] R 1 and R 2 is a hydrogen atom, A is a group represented by the following general formula (2a-1) or (2b-1), and D is any of the groups represented by the following general formulas (3a-1) to (3e-1):

[0019] [ka]

[0020] (In the above formula, Q 11 , Q 41 , Q 51 and Q 81 is a hydrogen atom, Q 21 , Q 31 , Q61 and Q 71 are each independently a fluorine atom or a chlorine atom, or Q 11 ~Q 81 are each independently a hydrogen atom, a fluorine atom, or a chlorine atom.

[0021] [ka]

[0022] (In the above formula, Y 15 , Y 16 and Y 18 ~Y 22 each independently represents a sulfur atom or CZ 1 =CZ 2 Y 16 When is a sulfur atom, Y 17 is a sulfur atom, and Y 16 CZ 1 =CZ 2 When Y 17 is an oxygen atom or a sulfur atom. 22 and Y 23 Relationship with Y 16 and Y 17 The relationship is the same as Z. 1 and Z 2 are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group. [6] The photoelectric conversion element according to [1], wherein the compound represented by formula (1) includes at least one selected from the compounds represented by the following general formulae (1a-1) to (1a-4) and (1b-1) to (1b-4):

[0023] [ka]

[0024] (In the above formula, Y 24 , Y 25 , Y 27 ~Y 31 , Y 33 and Y 35 each independently represents a sulfur atom or CZ 1 =CZ2 Y 25 When Y is a sulfur atom 26 is a sulfur atom, and Y 25 CZ 1 =CZ 2 When Y 26 is an oxygen atom or a sulfur atom. 28 and Y 29 Relationship with Y 31 and Y 32 Relationship with Y 31 and Y 32 Relationship with Y 33 and Y 34 The relationship with Y 25 and Y 26 The relationship is the same as Z. 1 and Z 2 are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group. [7] The photoelectric conversion element according to any one of [1] to [6], wherein the compound represented by the formula (1) is contained in a photoelectric conversion layer as a p-type semiconductor material. [8] An image sensor comprising the photoelectric conversion element according to any one of [1] to [7]. [9] A fingerprint sensor comprising the photoelectric conversion element according to any one of [1] to [7].

[10] A pulse wave sensor comprising the photoelectric conversion element according to any one of [1] to [7]. Effect of the Invention

[0025] According to the present invention, there is provided a photoelectric conversion element containing a compound that is particularly useful as a p-type semiconductor material having high sensitivity to green light and a precisely designed absorption wavelength, and an image sensor, a fingerprint sensor, and a pulse wave sensor that use the photoelectric conversion element. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a cross-sectional view illustrating a schematic example of an embodiment of a photoelectric conversion element of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention will be described in further detail below by presenting preferred embodiments of the invention. However, the following description is one example of an embodiment of the present invention, and the present invention is not limited to the contents described below as long as it does not go beyond the gist of the invention. In this specification, the use of "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower limit and upper limit.

[0028] [Photoelectric conversion element] The photoelectric conversion element of the present invention is a photoelectric conversion element containing a compound represented by the general formula (1) described below. Hereinafter, the compound represented by formula (1) will also be referred to as "compound (1)", and the same applies to compounds represented by other formulas.

[0029] <Compound (1)> Compound (1) is a compound represented by the following general formula (1).

[0030] [ka]

[0031] In the formula (1), D is a group consisting of one or two selected from a monocyclic heteroaryl group, a fused heteroaryl group consisting of two fused rings, a monocyclic aryl group, and a fused aryl group consisting of two fused rings, and contains at least a heteroaryl ring, and the heteroaryl ring is always bonded to L. L is a thiophene ring in which one or more hydrogen atoms may be substituted, or a thienothiophene ring in which one or more hydrogen atoms may be substituted. A is a group represented by the following general formula (2). A=CH- and D are bonded to the thiophene ring or thienothiophene ring of L. A=CH- and D are bonded to the thiophene ring or thienothiophene ring of L.

[0032] [ka]

[0033] In the formula (2), Z is a benzene ring or a naphthalene ring in which one or more hydrogen atoms may be substituted, and X is an oxygen atom or a dicyanomethylene group.

[0034] (ring L) L is a thiophene ring in which one or more hydrogen atoms may be substituted, or a thienothiophene ring in which one or more hydrogen atoms may be substituted. Substituents that the thiophene ring or thienothiophene ring may have include a deuterium atom, an alkyl group, C(═O)OR (wherein R is an alkyl group or an aryl group), an amino group, etc. From the viewpoint of ease of synthesis, these substituents are preferably a deuterium atom or an alkyl group having 1 to 10 carbon atoms, and more preferably a deuterium atom or an alkyl group having 1 to 10 carbon atoms. The thiophene ring or thienothiophene ring of L preferably has no substituents other than A=CH-- and D, in order to enhance the planarity of the molecule in order to achieve high mobility.

[0035] (Substituent D) D is a group consisting of one or a combination of two selected from a monocyclic heteroaryl group, a fused ring heteroaryl group consisting of two fused rings, a monocyclic aryl group, and a fused ring aryl group consisting of two fused rings, and contains at least a heteroaryl ring bonded to L. Examples of D include the following (i) to (ix). (i) Monocyclic heteroaryl group (ii) a fused ring heteroaryl group consisting of two fused rings (iii) A monovalent group in which two monocyclic heteroaryl groups are linked together (iv) A monovalent group in which two bicondensed ring-containing heteroaryl groups are linked together. (v) A group in which one of the hydrogen atoms of a monocyclic heteroaryl group is replaced by a fused-ring heteroaryl group consisting of two fused rings, a monocyclic aryl group, or a fused-ring aryl group consisting of two fused rings. (vi) A group in which one of the hydrogen atoms of a fused ring heteroaryl group consisting of two fused rings is replaced by a monocyclic heteroaryl group, a monocyclic aryl group, or a fused ring aryl group consisting of two fused rings.

[0036] The aryl ring of D may have one or more hydrogen atoms substituted. Similarly, the heteroaryl ring of D may have one or more hydrogen atoms substituted. Examples of the substituent that may be substituted on the aryl ring or heteroaryl ring of D include a chlorine atom, a fluorine atom, a bromine atom, an alkyl group, and a cyano group. From the viewpoint of improving sublimability, a fluorine atom is preferred.

[0037] From the viewpoint of improving the hole transport property, D is preferably any one of the groups represented by the following general formulas (3a) to (3e).

[0038] [ka]

[0039] In the above formula, Y 1 , Y 3 , Y 7 , Y 9 and Y 12 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or NZ 3 Y 2 , Y 4 , Y 6 , Y 8 , Y 10 , Y 11 and Y 13 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ 1 =CZ 2 Y 5 and Y 14 each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ 1 =CZ 2 or NZ 3 It is. 1 and Z 2are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group. 3 is an alkyl group or an aryl group.

[0040] Y 1 , Y 3 , Y 7 , Y 9 and Y 12 As the alkyl group, a sulfur atom is preferable from the viewpoint of ease of synthesis. Y 5 and Y 14 As the electron donor, an oxygen atom or a sulfur atom is preferred from the viewpoint of increasing the planarity of the molecule in order to achieve high mobility. Y 2 , Y 4 , Y 6 , Y 8 , Y 10 , Y 11 and Y 13 From the viewpoint of ease of synthesis, each of the groups is independently a sulfur atom or CZ 1 =CZ 2 is preferred.

[0041] Z 1 and Z 2 The alkyl group may be linear or branched. Z 1 and Z 2 As the alkyl group, from the viewpoint of heat resistance, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. Z 1 and Z 2 From the viewpoint of ease of synthesis, each of the groups is preferably a hydrogen atom, a fluorine atom, or an alkyl group, and more preferably a hydrogen atom.

[0042] Z 3 The alkyl group may be linear, branched, or cyclic. Z 3 As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferred from the viewpoint of ease of synthesis, and a methyl group, an ethyl group, or a cyclohexyl group is more preferred. Z 3As the aryl group, an aryl group having 6 to 12 carbon atoms is preferable, and a phenyl group or naphthyl group is more preferable, from the viewpoint of ease of synthesis.

[0043] The aryl ring or heteroaryl ring in the groups represented by formulae (3a) to (3e) may have one or more hydrogen atoms substituted, and the substituent is preferably a fluorine atom.

[0044] D is more preferably any of the groups represented by the following general formulas (3a-1) to (3e-1) because it has high hole transport properties.

[0045] [ka]

[0046] In the above formula, Y 15 , Y 16 and Y 18 ~Y 22 each independently represents a sulfur atom or CZ 1 =CZ 2 Y 16 When Y is a sulfur atom 17 is a sulfur atom, and Y 16 CZ 1 =CZ 2 When Y 17 is an oxygen atom or a sulfur atom. 22 and Y 23 Relationship with Y 16 and Y 17 The relationship is the same as Z. 1 and Z 2 are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group.

[0047] The aryl ring or heteroaryl ring in the groups represented by the general formulae (3a-1) to (3e-1) may have one or more hydrogen atoms substituted, and the substituent is preferably a fluorine atom.

[0048] (Substituent A) A is a group represented by the following general formula (2).

[0049] [ka]

[0050] In the formula (2), Z is a benzene ring or a naphthalene ring in which one or more hydrogen atoms may be substituted, and X is an oxygen atom or a dicyanomethylene group.

[0051] Substituents for Z which may be substituted on the benzene ring or naphthalene ring include a fluorine atom, a chlorine atom, a bromine atom, and a cyano group, with a fluorine atom and a chlorine atom being preferred from the standpoint of ease of synthesis. From the viewpoint of heat resistance, X is preferably an oxygen atom.

[0052] From the viewpoint of ease of synthesis, A is preferably a group represented by the following general formula (2a) or (2b).

[0053] [ka]

[0054] In the formulas (2a) and (2b), Q 1 ~Q 8 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group. 1 and X 2 are each independently an oxygen atom or a dicyanomethylene group.

[0055] A is more preferably a group represented by the following general formula (2a-1) or (2b-1).

[0056] [ka]

[0057] In the above formula, Q 11 , Q 41 , Q 51 and Q81 is a hydrogen atom, Q 21 , Q 31 , Q 61 and Q 71 are each independently a fluorine atom or a chlorine atom, or Q 11 ~Q 81 each independently represents a hydrogen atom, a fluorine atom or a chlorine atom.

[0058] Since compound (1) is a p-type semiconductor of the photoelectric conversion element, it is preferable that compound (1) contains at least one of the following compounds (1a) and (1b), and it is more preferable that compound (1a) and compound (1b) are at least one of them.

[0059] [ka]

[0060] In the above formula, R 1 and R 2 are each independently a hydrogen atom, a deuterium atom, an alkyl group, C(=O)OR (wherein R is an alkyl group or an aryl group), or an amino group.

[0061] R 1 and R 2 The alkyl group may be linear or branched. R 1 and R 2 As the alkyl group, from the viewpoint of heat resistance, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. R 1 and R 2 From the viewpoint of ease of synthesis, each of the groups is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0062] Since compound (1) is a p-type semiconductor of the photoelectric conversion element, it is more preferable that compound (1) includes at least one selected from the following compounds (1a-1) to (1a-4) and compounds (1b-1) to (1b-4), and it is even more preferable that compound (1) is at least one selected from the following compounds (1a-1) to (1a-4) and compounds (1b-1) to (1b-4).

[0063] [ka]

[0064] In the above formula, Y 24 , Y 25 , Y 27 ~Y 31 , Y 33 and Y 35 each independently represents a sulfur atom or CZ 1 =CZ 2 Y 25 When is a sulfur atom, Y 26 is a sulfur atom, and Y 25 CZ 1 =CZ 2 When Y 26 is an oxygen atom or a sulfur atom. 28 and Y 29 Relationship with Y 31 and Y 32 Relationship with Y 31 and Y 32 Relationship with Y 33 and Y 34 The relationship with Y 25 and Y 26 The relationship is the same as Z. 1 and Z 2 are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group.

[0065] The aryl ring or heteroaryl ring in the compounds (1a-1) to (1a-4) and the compounds (1b-1) to (1b-4) may have one or more hydrogen atoms substituted, and the substituent is preferably a fluorine atom.

[0066] Specific examples of the compound (1a-1) include the compounds (1a-1-1) to (1a-1-8).

[0067] [ka]

[0068] Specific examples of the compound (1a-2) include the compounds (1a-2-1) to (1a-2-9).

[0069] [ka]

[0070] Specific examples of the compound (1a-3) include the compounds (1a-3-1) to (1a-3-6).

[0071] [ka]

[0072] Specific examples of the compound (1a-4) include the compounds (1a-4-1) to (1a-4-4).

[0073] [ka]

[0074] Specific examples of the compound (1b-1) include the compounds (1b-1-1) to (1b-1-8).

[0075] [ka]

[0076] Specific examples of the compound (1b-2) include the compounds (1b-2-1) to (1b-2-8).

[0077] [ka]

[0078] Specific examples of the compound (1b-3) include the compounds (1b-3-1) to (1b-3-10).

[0079] [ka]

[0080] Specific examples of the compound (1b-4) include the compounds (1b-4-1) to (1b-4-4).

[0081] [ka]

[0082] (Action and effect of compound (1)) By using compound (1) as a p-type semiconductor material, the sensitivity of the photoelectric conversion element to green light is increased, making the photoelectric conversion element suitable for sensors such as image sensors, fingerprint sensors, and pulse wave sensors. The reason why compound (1) has high sensitivity to green light, which is useful as a p-type semiconductor material for photoelectric conversion elements, is not clear, but is presumed to be as follows. In compound (1), the electron-donating moiety has a structure in which one or two monocyclic or dicondensed aryl or heteroaryl rings are linked to a thiophene ring or a thienothiophene ring. In this way, the electron-donating moiety of compound (1) has a molecular design in which a small π-conjugated system is linked, compared to when a tricondensed ring in which three rings are condensed is included, and it is believed that this makes it possible to design a more precise absorption wavelength.

[0083] (Production method of compound (1)) The method for producing compound (1) is not particularly limited. Hereinafter, as an example of the method for producing compound (1), a method for producing compound (A) will be specifically described. 1and Y 24 is as described above.

[0084] [ka]

[0085] Compound (A) can be obtained by reacting compound (B) with compound (C) in a solvent in the presence of a base catalyst.

[0086] [ka]

[0087] Compound (B) may be a commercially available product or may be synthesized by a known method. Compound (C) may be a commercially available product or may be synthesized by a known method (e.g., Angew.Chem.Int.Ed.2017,56,304, Angew.Chem.Int.Ed.2017,56,15746, JP2022-511781A, JP2023-500815A, etc.).

[0088] Examples of base catalysts include piperidine and pyridine, and examples of acid catalysts include p-toluenesulfonic acid hydrate (PTSA·H2O). The equivalent ratio of compound (C) to compound (B) is preferably 0.8 to 1.5 equivalents. The equivalent ratio of the acid catalyst to the compound (B) is preferably 0.1 to 10 equivalents.

[0089] The solvent used in the reaction of compound (B) with compound (C) is not particularly limited as long as it does not react with the raw material compounds, and examples thereof include chloroform, methanol, and ethanol. The reaction temperature is preferably from room temperature to 100°C. The reaction time is preferably 0.5 to 24 hours.

[0090] <Photoelectric conversion element structure> The photoelectric conversion element of the present invention may have a known structure except that it contains the compound (1). In the photoelectric conversion element of the present invention, one type of compound (1) may be used alone, or two or more types of compounds (1) may be used in combination. In the photoelectric conversion element of the present invention, compound (1) is preferably contained in the photoelectric conversion layer (active layer) as a p-type semiconductor material.

[0091] The structure of the photoelectric conversion element can be that of a known organic photoelectric conversion element. For example, the description in JP-A-2007-324587 can be referred to. The specific structure is not particularly limited, but examples thereof include an element having a laminated structure in which a photoelectric conversion layer (active layer) is sandwiched between a pair of electrodes.

[0092] Hereinafter, an example of the photoelectric conversion element of the present invention will be described with reference to FIG. In addition, in each drawing used in the following description, characteristic parts may be enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may differ from the actual ones. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and can be appropriately changed and implemented within the scope of the present invention.

[0093] A photoelectric conversion element 10 shown in FIG. 1 has a structure in which a transparent electrode 12, a hole transport layer 13, a photoelectric conversion layer 14, an electron transport layer 15, and a metal electrode 16 are laminated in this order on a transparent substrate 11. The positions of the hole transport layer 13 and the electron transport layer 15 may be interchanged. That is, the photoelectric conversion element may have a structure in which a transparent electrode, an electron transport layer, a photoelectric conversion layer (active layer), a hole transport layer, and a metal electrode are laminated in this order on a transparent substrate.

[0094] The transparent substrate 11 may be a base material having an average transmittance of 80% or more for visible light of 450 nm or more. Examples of materials for forming the transparent substrate 11 include glass and plastics such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polyethylene sulfide.

[0095] The transparent electrode 12 may be an electrode having an average transmittance of 80% or more for visible light of 450 nm or more. The material for forming the transparent electrode 12 is not particularly limited as long as it can form the transparent electrode 12, but examples include tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), tungsten-doped indium oxide (IWO), zinc aluminum oxide (AZO), indium oxide (In2O3), zinc oxide (ZnO), titanium oxide (TiO2), and the like.

[0096] The metal electrode 16 is an electrode that forms a pair with the transparent electrode 12 . The material constituting the metal electrode 16 is not particularly limited, but examples include metals such as gold, platinum, silver, aluminum, nickel, titanium, magnesium, calcium, barium, sodium, chromium, copper, and cobalt, or alloys thereof. The metal electrode 16 is preferably a transparent electrode or a reflective electrode. That is, the photoelectric conversion element preferably has a laminated structure in which a photoelectric conversion layer (active layer) is sandwiched between a pair of electrodes (transparent or metal), and more preferably has a laminated structure in which an electron transport layer, a photoelectric conversion layer (active layer), and a hole transport layer are sandwiched between a pair of electrodes (transparent or metal). In the case of a pair of transparent electrodes, the materials forming the electrodes may be the same or different.

[0097] The thickness of the metal electrode 16 is not particularly limited, but is preferably about 10 nm from the viewpoint of enhancing transparency. If transparency is not required, the thickness is preferably 40 nm or more, and more preferably 100 nm or more, taking into consideration durability and the like.

[0098] The method for forming the transparent electrode 12 and the metal electrode 16 is not particularly limited, but they can be formed by, for example, a dry process such as vacuum deposition or sputtering; or a wet process using a conductive ink or the like.

[0099] When the hole transport layer 13 and the electron transport layer 15 are provided, the constituent members and the manufacturing method thereof are not particularly limited, and known techniques can be used. For example, the members and the manufacturing methods thereof described in known documents such as WO 2013 / 171517, WO 2013 / 180230, or JP 2012-191194 A can be used.

[0100] The photoelectric conversion layer 14 is a layer that absorbs light and separates electric charges. The photoelectric conversion layer 14 of the photoelectric conversion element of the present invention is a layer containing the above-mentioned compound (1). The photoelectric conversion layer 14 may contain a component other than the compound (1). Examples of the component other than the compound (1) include an n-type semiconductor material such as C60 fullerene or a non-fullerene acceptor.

[0101] The content of compound (1) in the photoelectric conversion layer 14 is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on the total mass of the photoelectric conversion layer 14. The content of compound (1) in the photoelectric conversion layer 14 is preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on the total mass of the photoelectric conversion layer 14. The preferred lower and upper limits of the content of compound (1) in the photoelectric conversion layer 14 can be arbitrarily combined, and for example, 30 to 100% by mass is preferred.

[0102] The thickness of the photoelectric conversion layer 14 is preferably 1 nm or more, more preferably 10 nm or more. If the thickness of the photoelectric conversion layer 14 is equal to or more than the lower limit, a sufficient amount of light absorption is easily obtained. On the other hand, the thickness of the photoelectric conversion layer 14 is preferably 1000 nm or less, more preferably 500 nm or less, and even more preferably 250 nm or less. If the thickness of the photoelectric conversion layer 14 is equal to or less than the upper limit, it is preferable in terms of external quantum efficiency (EQE). The preferable lower and upper limits of the thickness of the photoelectric conversion layer 14 can be arbitrarily combined, and for example, 10 to 250 nm is preferable.

[0103] The photoelectric conversion layer 14 may be formed, for example, by co-evaporating the compound (1) as a p-type semiconductor material and an n-type semiconductor material on a layer that will be under the photoelectric conversion layer 14, such as the hole transport layer 13, or by single-evaporating the compound (1) as a p-type semiconductor material and the n-type semiconductor material in this order to form two layers. The photoelectric conversion layer 14 may also be formed by applying a composition containing the compound (1), the n-type semiconductor material, and a solvent onto a substrate and drying to remove the solvent. Examples of methods for applying the composition include brush coating, bar coating, spray coating, dip coating, spin coating, curtain coating, and inkjet printing.

[0104] The photoelectric conversion element 10 can be obtained, for example, by forming a transparent electrode 12, a hole transport layer 13, a photoelectric conversion layer 14, an electron transport layer 15, and a metal electrode 16 on a transparent substrate 11 in this order.

[0105] [Image sensor, fingerprint sensor, pulse wave sensor] The use of the photoelectric conversion element of the present invention is not particularly limited, but it is suitable for an image sensor, a fingerprint sensor, and a pulse wave sensor. The image sensor, fingerprint sensor, and pulse wave sensor may have a known structure. Specifically, the image sensor may have a structure in which metal wiring, the photoelectric conversion element of the present invention, a color filter, and a microlens are laminated in this order on a substrate such as a silicon substrate. EXAMPLES

[0106] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following description.

[0107] [Synthesis Example 1] 5.00 g (18.1 mmol) of commercially available (1a-1-1-1), 3.17 g (21.7 mmol) of commercially available 1,3-indandione, and 140 mL of chloroform were placed in a reaction vessel and stirred to dissolve, after which 5.7 mL of piperidine was added and stirred for 1 hour at 60° C. After cooling, the solvent was distilled off and methanol was added instead, and the solid was dispersed and filtered to obtain 7.30 g of a solid. 1 H-NMR analysis confirmed that the obtained solid was compound (1a-1-1) (yield 99%). 1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ7.97-7.94(m,2H), 7.93(s,1H), 7.87(d,1H), 7.75-7 .81(m,2H), 7.41(d,1H), 7.28-7.30(m,2H), 7.24(dd,1H), 7.17(d,1H), 7.06(dd,1H).

[0108] [ka]

[0109] [Synthesis Example 2] 0.21 g (0.77 mmol) of commercially available (1a-1-1-1), 0.17 g (0.92 mmol) of 5,6-difluoro-1,3-indandione synthesized by the method described in JP 2021-132132 A, and 6 mL of chloroform were placed in a reaction vessel and stirred to dissolve, after which 0.24 mL of piperidine was added and stirred at 60 ° C. for 1 hour. After cooling, the solvent was distilled off, methanol was added instead, the solid was dispersed and filtered, and 0.29 g of solid was obtained. LC-MS analysis revealed that the main peak was identified as m / z 439.98 (M -) was observed, and the obtained solid was confirmed to be compound (1a-1-2) (yield 85%).

[0110] [ka]

[0111] [Synthesis Example 3] 2-Pentafluorophenylthiophene (1.80 g, 6.26 mmol) synthesized by the method described in J. Org. Chem. 2014, 79, 4161. was dissolved in 12 mL of tetrahydrofuran (THF) and cooled in a dry ice acetone bath. Lithium diisopropylamide (Kanto Chemical, 1.1 M, 6.0 mL, 6.6 mmol) was slowly added dropwise and stirred for 1 hour. Next, a THF solution of trimethyltin chloride (1.37 g, 6.9 mmol) was added under cooling, and the mixture was stirred for 30 minutes and then warmed to room temperature. Water and hexane were added, and the organic phase was washed three times with water. The solvent was distilled off, and hexane was added to the obtained solid, followed by filtration. The filtrate was concentrated to obtain compound (1b-1-1-1) in a yield of 57%. Compound (1b-1-1-1) 1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ7.44(d,1H), 7.25(d,1H), δ0.42(s,9H).

[0112] [ka]

[0113] Compound (1b-1-1-1) (992 mg, 2.4 mmol), 5-bromothieno[3,2-b]thiophene-2-carbaldehyde (493.6 mg, 2.0 mmol) synthesized by the method described in RSC Adv., 2013, 3, 22544., and bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (14.6 mg, 0.021 mmol) were dissolved in 10 mL of toluene, stirred for 2 hours in an oil bath set at 100°C, and then cooled to room temperature. Methanol was added to the reaction solution, which was then subjected to ultrasonic treatment and then filtration to obtain a solid. The obtained solid was dried under reduced pressure and purified by silica gel column chromatography (developing solvent: chloroform) to obtain compound (1b-1-1-2) in a yield of 87%. Compound (1b-1-1-2) 1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ9.96(s,1H), 7.91(d,1H), 7.52(d,1H), 7.49(d,1H), 7.36(d,1H).

[0114] [ka]

[0115] 0.30 g (0.72 mmol) of compound (1b-1-1-2), 0.16 g (0.86 mmol) of 5,6-difluoro-1,3-indandione synthesized by the method described in JP 2021-132132 A, and 17 mL of chloroform were placed in a reaction vessel and stirred to dissolve, after which 0.34 mL of piperidine was added and stirred at 60 ° C. for 1 hour. After cooling, the solvent was distilled off, methanol was added instead, the solid was dispersed and filtered, and 0.35 g of a solid was obtained. LC-MS analysis revealed that the main peak was identified as m / z 579.95 (M - ) was observed, and the obtained solid was confirmed to be compound (1b-1-1) (yield 85%).

[0116] [ka]

[0117] [Synthesis Example 4] Compound (X-1-1) (2.00 g, 9.69 mmol) synthesized by the method described in J. Mater. Chem. A, 2020, 8, 5194. was dissolved in THF (100 mL) and cooled in a dry ice acetone bath. n-Butyl lithium solution (6.8 mL, 1.56 M, 10.66 mmol) was slowly added dropwise thereto. After stirring for 2 hours while cooling with a dry ice acetone bath, trimethyltin chloride (2.70 g, 13.57 mmol) dissolved in THF (13 mL) was added dropwise, stirred for 30 minutes, and then the dry ice acetone bath was removed and stirred for another 2 hours. Water and hexane were added, and the organic layer was washed with a saturated aqueous sodium chloride solution to obtain 3.77 g of a compound. 1 H-NMR analysis confirmed that the obtained compound was compound (X-1-2) (yield 99%). 1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ7.12(d,1H), 7.02(s,1H), 6.97(d,1H), 1.49(s,6H), 0.39(s,9H).

[0118] [ka]

[0119] Compound (X-1-2) (1.00 g, 2.71 mmol), commercially available 5-bromo-2-formylthiophene (0.62 g, 3.25 mmol), and Pd(Amphos)Cl2 (0.02 mg, 0.027 mmol) were dissolved in 13 mL of toluene and heated and stirred at 80° C. for 2 hours. After removing the solvent under reduced pressure, the product was purified by silica gel column chromatography to obtain 0.66 g of compound (yield 77%). 1 The obtained compound was confirmed to be compound (X-1-3) by H-NMR analysis.1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ9.84(s,1H), 7.65(d,1H), 7.25-7.26(m,2H), 7.21(d,1H), 7.01(d,1H), 1.49(s,6H).

[0120] [ka]

[0121] Compound (X-1-3) (0.10 g, 0.31 mmol), commercially available 1,3-indandione (0.055 g, 7 g, 0.38 mmol), and 3 mL of chloroform were placed in a reaction vessel and stirred to dissolve, after which 0.11 mL of piperidine was added and stirred for 1 hour at 60° C. After cooling, the solvent was distilled off and methanol was added instead, and the solid was dispersed and filtered to obtain 0.099 g of a solid. 1 The obtained solid was confirmed to be compound (X-1) by H-NMR analysis (yield 71%). 1 The H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ7.94-7.97(m,2H), 7.92(s,1H), 7.82-7.83(m,1H ), 7.74-7.79(m,2H), 7.45(s,1H), 7.25-7.29(m,2H), 7.02(d,1H), 1.51(s,6H).

[0122] [ka]

[0123] [Evaluation of sensitivity to green light] The compounds obtained in each synthesis example were dissolved in dichloromethane and the absorption spectrum was measured. As a standard for evaluating the "sensitivity of the photoelectric conversion element to green light", the following judgment criteria were set with reference to the spectrum of a green-emitting LED (CL525A product from THORLABS). The results are shown in Table 1. <Judgment criteria> ○ (High sensitivity): Maximum absorption wavelength is 500 to 530 nm (green LED emission intensity is 60% or more) △ (medium sensitivity): Maximum absorption wavelength is 490nm or more and less than 500nm or more than 530nm and less than 545nm (green LED emission intensity is 30% or more and less than 60%) × (Low sensitivity): Maximum absorption wavelength is less than 490 nm or more than 545 nm

[0124] [Table 1]

[0125] As shown in Table 1, compound (1a-1-1), compound (1a-1-2), and compound (1b-1-1), in which D is a monocyclic or difused heteroaryl group, or a group in which these are bonded, can be said to have an advantageous wavelength design for absorbing green light, compared to compound (X-1), which contains a trifused heteroaryl group instead.

[0126] [Example 1] A transparent conductive film of indium tin oxide (ITO) was patterned on a transparent glass substrate as a transparent electrode. The electrode surface of the ITO substrate was treated with ozone for 10 minutes using an ultraviolet ozone cleaner (manufactured by Japan Laser Electronics Co., Ltd., product name "NL-UV253"). Next, compound (1a-1-1) as a p-type semiconductor material and C60 fullerene (manufactured by Frontier Carbon Corporation) as an n-type semiconductor material were co-deposited to form a photoelectric conversion layer having a thickness of 120 nm. On the photoelectric conversion layer, C60 fullerene (manufactured by Frontier Carbon Corporation) was deposited as an electron transport material in a vacuum to form an electron transport layer having a thickness of 40 nm. Finally, aluminum was deposited as a metal electrode material on the electron transport layer in a vacuum to form a metal electrode having a thickness of 100 nm, thereby obtaining a photoelectric conversion element.

[0127] [Example 2] A photoelectric conversion element was produced in the same manner as in Example 1, except that compound (1a-1-2) was used instead of compound (1a-1-1) as the p-type semiconductor material.

[0128] [Example 3] A photoelectric conversion element was produced in the same manner as in Example 1, except that compound (1b-1-1) was used as the p-type semiconductor material instead of compound (1a-1-1).

[0129] [Evaluation of photoelectric conversion ability] The photoelectric conversion element obtained in each example was irradiated with light under an applied voltage of -3 V, and evaluated using an action spectrum measuring device (manufactured by Peccell Technologies, product name "PEC-S20").

[0130] It was confirmed that all of the photoelectric conversion elements of Examples 1 to 3 functioned as photoelectric conversion elements in the evaluation of the photoelectric conversion ability. [Explanation of symbols]

[0131] 10 Photoelectric conversion element 11 Transparent substrate 12 Transparent electrode 13 Hole transport layer 14 Photoelectric conversion layer 15 Electron transport layer 16 Metal electrode

Claims

1. A photoelectric conversion element comprising a compound represented by the following general formula (1): 【Chemistry 1】 (In the formula (1), D is a group formed by combining one or two selected from a monocyclic heteroaryl group, a fused-ring heteroaryl group consisting of two fused rings, a monocyclic aryl group, and a fused-ring aryl group consisting of two fused rings, and contains at least a heteroaryl ring, and the heteroaryl ring is always bonded to L. L is a thiophene ring in which one or more hydrogen atoms may be substituted, or a thienothiophene ring in which one or more hydrogen atoms may be substituted. A is a group represented by the following general formula (2). A=A group represented by CH- and D are bonded to the thiophene ring or the thienothiophene ring of L.) 【Chemistry 2】 (In the formula (2), Z is a benzene ring or a naphthalene ring in which one or more hydrogen atoms may be substituted. X is an oxygen atom or a dicyanomethylene group.)

2. 2. The photoelectric conversion element according to claim 1, wherein D is any one of groups represented by the following general formulas (3a) to (3e): 【Chemistry 3】 (In the above formula, Y １ , Y ３ , Y ７ , Y ９ and Y １２ each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or NZ ３ It is. ２ , Y ４ , Y ６ , Y ８ , Y １０ , Y １１ and Y １３ each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ １ = CZ ２ It is. ５ and Y １４ each independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or CZ １ = CZ ２ or N.Z. ３ It is. １ and Z ２ are each independently a hydrogen atom, a deuterium atom, a fluorine atom or an alkyl group. ３ is an alkyl group or an aryl group.

3. The photoelectric conversion element according to claim 1 , wherein A is a group represented by the following general formula (2a) or (2b): 【Chemistry 4】 (In the above formulas (2a) and (2b), Q １ ~Q ８ are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group. １ and X ２ are each independently an oxygen atom or a dicyanomethylene group.

4. The photoelectric conversion element according to claim 1 , wherein the compound represented by formula (1) includes at least one of a compound represented by the following general formula (1a) and a compound represented by the following general formula (1b): 【Chemistry 5】 (In the above formula, R １ and R ２ are each independently a hydrogen atom, a deuterium atom, an alkyl group, C(=O)OR (wherein R is an alkyl group or an aryl group), or an amino group.

5. The R １ and R ２ is a hydrogen atom, The A is a group represented by the following general formula (2a-1) or (2b-1):

5. The photoelectric conversion element according to claim 4, wherein D is any one of groups represented by the following general formulas (3a-1) to (3e-1): 【Chemistry 6】 (In the above formula, Q １１ , Q ４１ , Q ５１ and Q. ８１ is a hydrogen atom, Q ２１ , Q ３１ , Q ６１ and Q. ７１ are each independently a fluorine atom or a chlorine atom, or Q １１ ~Q ８１ are each independently a hydrogen atom, a fluorine atom, or a chlorine atom. 【Chemistry 7】 (In the above formula, Y １５ , Y １６ and Y １８ ~Y ２２ each independently represents a sulfur atom or CZ １ = CZ ２ It is. １６ When Y is a sulfur atom １７ is a sulfur atom, and Y １６ CZ １ = CZ ２ When Y １７ is an oxygen atom or a sulfur atom. ２２ and Y ２３ Relationship with Y １６ and Y １７ The relationship is the same as １ and Z ２ are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group.

6. The compound represented by formula (1) includes at least one selected from the compounds represented by the following general formulas (1a-1) to (1a-4) and (1b-1) to (1b-4). The photoelectric conversion element according to claim 1. 【Chemistry 8】 (In the above formula, Y ２４ , Y ２５ , Y ２７ ~Y ３１ , Y ３３ and Y ３５ each independently represents a sulfur atom or CZ １ = CZ ２ It is. ２５ When Y is a sulfur atom ２６ is a sulfur atom, and Y ２５ CZ １ = CZ ２ When Y ２６ is an oxygen atom or a sulfur atom. ２８ and Y ２９ Relationship with Y ３１ and Y ３２ Relationship with Y ３１ and Y ３２ Relationship with Y ３３ and Y ３４ The relationship with Y ２５ and Y ２６ The relationship is the same as １ and Z ２ are each independently a hydrogen atom, a deuterium atom, a fluorine atom, or an alkyl group.

7. The photoelectric conversion element according to claim 1 , wherein the compound represented by the formula (1) is contained in a photoelectric conversion layer as a p-type semiconductor material.

8. An image sensor comprising the photoelectric conversion element according to any one of claims 1 to 7.

9. A fingerprint sensor comprising the photoelectric conversion element according to any one of claims 1 to 7.

10. A pulse wave sensor comprising the photoelectric conversion element according to any one of claims 1 to 7.

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