Near-infrared absorbing organic semiconductor ink, film, near-infrared absorbing organic semiconductor device, and near-infrared organic photodetector

Abstract

To provide a near-infrared absorbing organic semiconductor inks and the like that have high external quantum efficiency (EQE) in a near-infrared region and high resistance (heat resistance, light resistance, weather resistance).SOLUTION: An ink includes an indigo compound that can be synthesized using the compound of the following general formula as a raw material, a p-type organic semiconductor compound, an n-type organic semiconductor compound, and an organic solvent.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to near-infrared absorbing organic semiconductor inks, films, near-infrared absorbing organic semiconductor devices, and near-infrared organic photodetectors. [Background technology]

[0002] Organic photodetectors are expected to be applied to flexible and wearable electronic devices, and high-performance ultraviolet and visible light photodetectors have been realized. On the other hand, the near-infrared region, with an absorption wavelength of over 750 nm, is highly desirable for scientific and industrial applications due to its low attenuation in biological tissues and long propagation distances, but only a very limited number of organic compounds applicable to near-infrared photodetectors have been reported. In addition, organic photodetection is expected to be applied to medical diagnosis, environmental monitoring, agricultural production, and autonomous driving technology, but in order to adapt it to use in external environments, it is necessary to improve its resistance aspects such as heat resistance, light resistance, and weather resistance. Non-Patent Document 1 describes near-infrared absorbing organic semiconductor compounds that have been developed so far, but there is a problem with photoelectric conversion efficiency in the near-infrared region. Patent Documents 1 and 2 disclose that in an organic photoelectric conversion layer, a third compound is added and mixed in addition to a p-type organic semiconductor and an n-type organic semiconductor to form a bulk heterostructure, thereby improving photoelectric conversion efficiency, but there is no description regarding the near-infrared region. Patent Document 3 discloses an organic semiconductor device that uses a p-type semiconductor polymer compound, a unique n-type organic semiconductor compound, and an organic dye that has an absorption maximum at 850 to 1100 nm and a specified molar extinction coefficient at 940 nm in the active layer, but there is no description regarding resistance aspects (heat resistance, light resistance, weather resistance). [Prior art documents] [Patent documents]

[0003] [Non-Patent Document 1] Chem.Mater.2019, 31,6539 [Patent Document 1] JP 2015-92546 A [Patent Document 2] JP 2018-129505 A [Patent Document 3] Patent Publication No. 2022-30124 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a near-infrared absorbing organic semiconductor ink that has a high external quantum efficiency (EQE) in the near-infrared region and high durability (heat resistance, light resistance, weather resistance), a film using the same, a near-infrared absorbing organic semiconductor device, and a near-infrared organic photodetector. [Means for solving the problem]

[0005] The present inventors conducted extensive research to solve the above-mentioned problems and discovered that a near-infrared absorbing organic semiconductor ink containing a specific indigo compound, a p-type organic semiconductor compound, an n-type organic semiconductor compound, and an organic solvent has excellent photoelectric conversion efficiency in the near-infrared region and high resistance (heat resistance, light resistance, weather resistance), thereby completing the present invention.

[0006] That is, the present invention relates to a near-infrared absorbing organic semiconductor ink comprising an indigo compound (A) represented by the following general formula (1), general formula (2), or general formula (3), a p-type organic semiconductor compound (B), an n-type organic semiconductor compound (C), and an organic solvent.

[0007] [ka] [X1~X 52each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent, an arylalkyl group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, an amino group, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, a heterocycle which may have a substituent, a cyano group, or a halogen atom. 36 Two adjacent groups among the groups represented by the formula may be linked to form a ring structure together with the carbon atoms to which they are bonded. M1 and M2 each independently represent Zn, Co, Ni, or Pd. n represents the degree of polymerization and is 0 or more and 8 or less.]

[0008] The present invention also relates to the near infrared absorbing organic semiconductor ink, which further contains 1,8-diiodooctane or 1-chloronaphthalene as an additive.

[0009] The present invention also relates to a film formed from the near-infrared absorbing organic semiconductor ink.

[0010] The present invention also relates to a near-infrared absorbing organic semiconductor device comprising the above-mentioned film.

[0011] The present invention also relates to a near-infrared absorbing organic semiconductor device, characterized in that a photoelectric conversion layer is the above-mentioned film.

[0012] The present invention also relates to a near-infrared absorbing organic photodetector using the near-infrared absorbing organic semiconductor device. Effect of the Invention

[0013] The present invention can provide a near-infrared absorbing organic semiconductor ink that has excellent external quantum efficiency (EQE) in the near-infrared region and high resistance (heat resistance, light resistance, weather resistance). Furthermore, it can provide a coating using the near-infrared absorbing organic semiconductor ink, a near-infrared absorbing organic semiconductor device having the coating as a photoelectric conversion layer, and a near-infrared absorbing organic photodetector. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic cross-sectional view of a photoelectric conversion device including a film of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Definitions of terms used herein. "CI" as used herein means Color Index (CI). Colorants include pigments and dyes.

[0016] <Indigo Compound (A)> The indigo compound (A) in the present invention functions as a near-infrared absorbing dye. The indigo compound (A) is represented by the following general formula (1), general formula (2), or general formula (3). The maximum absorption wavelength of the indigo compound (A) is preferably in the range of 750 nm or more, more preferably in the range of 800 nm or more and 1300 nm or less.

[0017] [ka]

[0018] X1~X 52each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent, an arylalkyl group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, an amino group, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, a heterocycle which may have a substituent, a cyano group, or a halogen atom. 36 Two adjacent groups among the groups represented by the formula (I) may be linked to form a ring structure together with the carbon atoms to which they are bonded. M1 and M2 each independently represent Zn, Co, Ni, or Pd. n represents the degree of polymerization and is 0 to 8.

[0019] The alkyl group which may have a substituent may be any of a straight chain structure, a branched structure, a single ring structure, and a condensed polycyclic structure. For example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, an octadecyl group, an isopropyl group, an isobutyl group, an isopentyl group, a 2-ethylhexyl group, a 2-hexyldodecyl group, a sec-butyl group, a tert-butyl group, a sec-pentyl group, a tert-pentyl group, a tert-octyl group, a neopentyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a boronyl group, and a 4-decylcyclohexyl group.

[0020] The hydrogen atom in the alkyl group may be substituted with a substituent such as a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, an ester group, a sulfo group, a sulfanyl group, a sulfamoyl group, an amino group, an alkylamino group, or an amide group. The alkyl group may have a plurality of substituents. The substituents are not limited to those mentioned above.

[0021] The alkyl group may have a structure in which two or more alkyl groups (one of which is an alkylene group) are bonded to each other via a linking group. Specific examples of the linking group include an ester bond (-COO-), an ether bond (-O-), and a sulfide bond (-S-). That is, in this specification, the alkyl group may be, for example, a group represented by "-R'-OR" (R' represents an atomic group obtained by removing one hydrogen atom from the alkyl group). A specific example is -C2H4-O-C2H5.

[0022] Examples of the aryl group which may have a substituent include a phenyl group, a tolyl group, a biphenylyl group, a terphenylyl group, a quaterphenylyl group, a pentalenyl group, an indenyl group, a naphthyl group, a binaphthalenyl group, a ternaphthalenyl group, a quaternaphthalenyl group, an azulenyl group, a heptalenyl group, a biphenylenyl group, an indacenyl group, a fluoranthenyl group, an acephenanthrylenyl group, an aceanthrylenyl group, a phenalenyl group, a fluorenyl group, an anthryl group, a bianthracenyl group, and the like. Examples of the alkyl group include an anthranyl group, a teranthracenyl group, a quaternanthracenyl group, an anthraquinolyl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a pleiadenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a pentacenyl group, a tetraphenylenyl group, a hexaphenyl group, a hexacenyl group, a rubicenyl group, a coronenyl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a pyrantrenyl group, and a divalenyl group.

[0023] The hydrogen atom in the aryl group may be substituted with a substituent such as a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, an ester group, a sulfo group, a sulfanyl group, a sulfamoyl group, an amino group, an alkylamino group, or an amide group. The aryl group may have a plurality of substituents. The substituents are not limited to those mentioned above.

[0024] The alkoxyl group which may have a substituent is a group (--OR) in which an oxygen atom is bonded to the above-mentioned alkyl group (--R).

[0025] The optionally substituted aryloxy group is a group (-OAr) in which an oxygen atom is bonded to the above-mentioned aryl group (-Ar).

[0026] The arylalkyl group which may have a substituent is a group (-RAr) in which an aryl group (-Ar) is bonded to the above-mentioned alkyl group (-R).

[0027] The alkylthio group which may have a substituent is a group (-SR) in which a sulfur atom is bonded to the above-mentioned alkyl group (-R).

[0028] The optionally substituted arylthio group is a group (-SAr) in which a sulfur atom is bonded to the above-mentioned aryl group (-Ar).

[0029] The alkylamino group which may have a substituent is a secondary amino group or a tertiary amino group in which a nitrogen atom is bonded to the above-mentioned alkyl group (-R).

[0030] The arylamino group which may have a substituent is a secondary amino group or tertiary amino group in which a nitrogen atom is bonded to the above-mentioned aryl group (-Ar).

[0031] The heterocycle which may have a substituent is a cyclic compound containing at least two different elements in a 5- or 6-membered ring structure, such as furan, pyrrole, pyrrolidine, pyrazole, oxazole, thiazole, triazole, pyridine, piperidine, morpholine, piperazine, benzofuran, benzothiophene, indole, benzimidazole, quinoline, isoquinoline, carbazole, acridine, phenoxazine, phenothiazine, and acridone.

[0032] The hydrogen atom in the heterocycle may be substituted with a substituent such as a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, an ester group, a sulfo group, a sulfanyl group, a sulfamoyl group, an amino group, an alkylamino group, or an amide group. The heterocycle may have a plurality of substituents. The substituents are not limited to those mentioned above.

[0033] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0034] X1~X 36 Two adjacent groups among the groups represented by the formula (I) may be linked to form a ring structure together with the carbon atoms to which they are bonded. The ring structure may have a substituent.

[0035] (Synthesis of indigo compound (A)) The indigo compound (A) can be synthesized using the compound represented by general formula (4) as a raw material.

[0036] General formula (4) [ka]

[0037] In general formula (4), X 53 ~X 60 is X1~X 52 is synonymous with.

[0038] The compound represented by general formula (4) can be obtained according to the synthesis method described in JP-A-2012-224593.

[0039] The indigo compound (A) can be obtained by reacting the compound represented by the general formula (4) with a boron compound or a metal complex, with the addition of a Lewis acid such as titanium tetrachloride or aluminum chloride, if necessary.

[0040] The reaction temperature is not particularly limited, but is preferably in the range of 40 to 170°C, and more preferably 50 to 130°C.

[0041] The reaction solvent is not particularly limited, but is preferably one in which the intermediate and the boron compound or metal complex are soluble, specific examples of which include tetrahydrofuran, toluene, xylene, and bromobenzene.

[0042] When using a boron compound, a borate ester is preferred, and 2-aminoethyl diphenyl borate is particularly preferred.

[0043] The reaction time is not particularly limited, but the progress of the reaction may be confirmed by MALDI TOF-MS spectrum or spectrophotometer to confirm the disappearance of the raw materials.

[0044] Examples of the indigo compound (A) include the following compounds. In the formula, n represents the degree of polymerization and is 0 or more and 8 or less. The present invention is not limited thereto.

[0045] [Chemical formula]

[0046] [Chemical formula]

[0047] <p-type organic semiconductor compound (B)> In the present invention, the p-type organic semiconductor compound (B) is a hole-transporting organic compound exhibiting p-type organic semiconductor properties, and examples include low-molecular compounds and high-molecular compounds. For example, rubrene derivatives, acene derivatives such as anthracene, tetracene, pentacene, heteroacene derivatives, thiophene derivatives, thiazole derivatives, triarylamine derivatives, fluorene derivatives, carbazole derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, diketopyrrolopyrrole derivatives, benzodifuranone derivatives, etc. are included. Specific structures include the compounds of the following (B-1 to B-4). In the formula, n represents the degree of polymerization and is a positive number. The present invention is not limited thereto.

[0048] [Chemical formula]

[0049] <n-type organic semiconductor compound (C)> In the present invention, the n-type organic semiconductor compound (C) is an electron transporting organic compound exhibiting n-type organic semiconductor properties, and includes low molecular weight compounds and polymeric compounds. For example, fullerene derivatives, rubrene derivatives, halogenated acene derivatives such as anthracene, tetracene, and pentacene, heteroacene derivatives, perylene derivatives, thiophene derivatives, thiazole derivatives, fluorene derivatives, carbazole derivatives, halogenated phthalocyanine derivatives, diketopyrrolopyrrole derivatives, and benzodifuranone derivatives are included. Specific structures include the following compounds (C-1 to C-4). In the formula, n indicates the degree of polymerization and is a positive number. The present invention is not limited to these.

[0050] [ka]

[0051] <Organic solvent> The near infrared absorbing organic semiconductor ink of the present invention contains an organic solvent. Specifically, the organic solvent may be ethyl lactate, butyl lactate, benzyl alcohol, 1,2,3-trichloropropane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, 1,4-dioxane, 2-heptanone, 2-methyl-1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, 3-ethoxyethyl propionate, 3-methyl-1,3-butanediol, 3-methoxy-3- Methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m-diethylbenzene, m-dichlorobenzene, N,N-dimethylacetamide, N,N-dimethylformamide, n-butyl alcohol, n-butylbenzene, n-propyl acetate, o-xylene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene ketone, γ-butyrolactone, isobutyl alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monopropyl ether, ethylene glycol monohexyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, cyclohexanol, cyclohexanol acetate, cyclohexanone, cyclopentanone,Examples of the esters include dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, 4-hydroxy-4-methyl-2-pentanone, N-methylpyrrolidone, benzyl alcohol, methyl isobutyl ketone, methylcyclohexanol, n-amyl acetate, n-butyl acetate, isoamyl acetate, isobutyl acetate, propyl acetate, and dibasic acid esters, but the present invention is not limited thereto. ,

[0052] <Near-infrared absorbing organic semiconductor ink> The near-infrared absorbing organic semiconductor ink of the present invention contains an indigo compound (A), a p-type organic semiconductor compound (B), an n-type organic semiconductor compound (C), and an organic solvent.

[0053] The content of the indigo compound (A) in the near infrared absorbing organic semiconductor ink is preferably 0.2 mass % or more and 1.0 mass % or less, more preferably 0.3 mass % or more, and even more preferably 0.4 mass % or more.

[0054] The content of the p-type organic semiconductor compound (B) in the near infrared absorbing organic semiconductor ink is preferably 0.4 mass % or more and 1.5 mass % or less, more preferably 0.6 mass % or more, and even more preferably 0.8 mass % or more.

[0055] The content of the n-type semiconductor organic compound (C) in the near infrared absorbing organic semiconductor ink is preferably 0.6% by mass or more and 2.0% by mass or less, more preferably 0.8% by mass or more, and even more preferably 1.0% by mass or more.

[0056] From the viewpoint of coating properties, the organic solvent in the near infrared absorbing organic semiconductor ink is preferably toluene, xylene, chloroform, or 1-chlorobenzene.

[0057] The organic solvent in the near infrared absorbing organic semiconductor ink may be used alone or in combination of two or more kinds.

[0058] <Additives> The near-infrared absorbing organic semiconductor ink preferably contains 1,8-diiodooctane or 1-chloronaphthalene as an additive for the purpose of stabilizing the bulk heterostructure of the indigo compound (A), the p-type organic semiconductor compound (B), and the n-type organic semiconductor compound (C). 1,8-diiodooctane or 1-chloronaphthalene can promote π-stacking of the p-type organic semiconductor compound (B) and the n-type organic semiconductor compound (C), and can promote the formation of a bulk heterostructure between the p-type organic semiconductor compound (B) and the n-type organic semiconductor compound (C).

[0059] Based on the total amount of organic solvent in the near-infrared absorbing organic semiconductor ink, 1,8-diiodooctane or 1-chloronaphthalene is preferably added in an amount of 0.5 to 5.0 volume %, more preferably 1.0 to 3.0 volume %, and even more preferably 1.5 to 2.5 volume %.

[0060] <Membrane> The near-infrared absorbing organic semiconductor ink of the present invention can be used to form a coating film by, but not limited to, a spin coating method, an inkjet method, a silk screen method, a bar coater method, a transfer method, or a spray method. From the viewpoint of simplicity, the spin coating method is preferred.

[0061] <Near-infrared absorbing organic semiconductor device> Near-infrared absorbing organic semiconductor devices using a coating film formed from the near-infrared absorbing organic semiconductor ink of the present invention include, but are not limited to, organic field effect transistors and photoelectric conversion devices such as organic photodetectors and organic thin-film solar cells. From the viewpoint of adding an indigo compound (A) having high absorption in the near-infrared region, photoelectric conversion devices are preferred, and organic photodetectors are more preferred.

[0062] (Photoelectric conversion device) Specific examples of the photoelectric conversion device structure are shown in FIG. 1, but the present invention is not limited thereto.

[0063] Examples of electrode materials include metals such as silver, gold, platinum, copper, iron, zinc, tin, aluminum, indium, nickel, cobalt, scandium, yttrium, vanadium, indium, ytterbium, lithium, magnesium, sodium, and potassium, metal oxides such as indium, tin, molybdenum, and nickel, and composite metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), and gallium zinc oxide (GZO), but the present invention is not limited to these. It is preferable that at least one of the positive electrode and the negative electrode is transparent. It is preferable that the transparent electrode has an average transmittance of 80% or more in the visible region of 400 nm or more.

[0064] Examples of materials for the hole blocking layer and the electron blocking layer include conductive polymers such as polythiophene polymers, polyfluorene polymers, and polypyrrole polymers, and metal oxides such as graphene, molybdenum, tungsten, nickel, vanadium, zirconium, zinc, copper, and ruthenium, but the present invention is not limited to these.

[0065] <Near-infrared absorbing organic photodetector> The near-infrared absorbing organic semiconductor device of the present invention can be used as a near-infrared absorbing organic photodetector by being provided in an optical sensor or an image sensor. Since it contains the indigo compound (A) that functions as a near-infrared absorbing dye, it is excellent in detecting light in the near-infrared region. EXAMPLES

[0066] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these. In addition, "parts" means "parts by mass" and "%" means "% by mass".

[0067] Before describing the examples, each measurement method will be described.

[0068] (Method of identifying compounds) The compounds used in the present invention were identified by infrared absorption spectroscopy and MALDI TOF-MS spectroscopy. The MALDI TOF-MS spectroscopy was performed using a Bruker Daltonics MALDI mass spectrometer AutoflexIII, and the compounds were identified by the agreement of the molecular ion peaks in the mass spectra obtained in positive and negative modes with the mass numbers obtained by calculation.

[0069] (Maximum absorption wavelength of indigo compound (A)) The maximum absorption wavelength of the indigo compound (A) was measured by dissolving the indigo compound (A) in 1-chlorobenzene at 20 ppm, and then measuring the wavelength showing the maximum absorbance in the absorption spectrum in the range of 400 to 1300 nm using a UV-Vis-NIR spectrophotometer U-4150 (manufactured by Hitachi High-Technologies Corporation).

[0070] <Production of indigo compound (A)> (Production of Indigo Composition (A-1)) [ka]

[0071] In a four-neck flask, 26.6 parts of aniline, 120 parts of bromobenzene, and 53.5 parts of diazabicyclooctane were added and stirred for 20 minutes. Then, 45.2 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25.0 parts of indigo were added and heated under reflux for 10 hours under a nitrogen atmosphere. After the reaction was completed, 500 parts of methanol were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 25.6 parts of compound (1). In a four-neck flask, 10 parts of compound (1), 18.10 parts of nickel (II) acetate tetrahydrate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered and washed with 500 parts of methanol, and the solid content was dried to obtain 8.6 parts of the indigo composition represented by (A-1). n was 0 to 8 on the MALDI TOF-MS spectrum, and the maximum absorption wavelength was 820 nm.

[0072] (Production of Indigo Composition (A-2)) [ka]

[0073] In a four-neck flask, 25 parts of 6,6-dibromoindigo, 26.6 parts of phenothiazine, 77.6 parts of cesium carbonate, 1.4 parts of tris(dibenzylideneacetone)dipalladium(0), 1.4 parts of XPhos, and 120 parts of toluene were added and heated under reflux for 10 hours. After the reaction was completed, 100 parts of hexane were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 25.8 parts of compound (2). In a four-neck flask under a nitrogen atmosphere, 10.7 parts of aniline, 120 parts of bromobenzene, and 21.4 parts of diazabicyclooctane were added and stirred. Then, 18.1 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25 parts of compound (2) were added and heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 18.7 parts of compound (3). In a four-neck flask, 10 parts of compound (3), 8.2 parts of zinc acetate dihydrate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered, washed with 500 parts of methanol, and dried to obtain 7.7 parts of indigo composition (A-2). n was 0 to 8 on the MALDI TOF-MS spectrum, and the maximum absorption wavelength was 940 nm.

[0074] (Production of Indigo Composition (A-3)) [ka]

[0075] In a three-neck flask, 25 parts of 4-methoxyaniline, 1.9 parts of sodium hydrogen sulfide, 31.7 parts of 2-ethylhexanol, and 250 mL of dehydrated toluene were added, and the mixture was heated under reflux for 10 hours under a nitrogen atmosphere. After the reaction was completed, the reaction mixture was cooled to room temperature, and the mixture was separated and extracted with water and ethyl acetate. The extract solution was washed with saturated saline, and then 30 g of anhydrous sodium sulfate was added to the extract solution, which was then allowed to stand for 15 minutes. After filtering off the sodium sulfate, the solvent of the extract solution was distilled off. The resulting reaction product was purified by distillation to obtain 33.7 parts of compound (4). In a four-neck flask, 63.3 parts of compound (4), 120 parts of bromobenzene, and 53.5 parts of diazabicyclooctane were added and stirred for 20 minutes. Then, 45.2 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 10.0 parts of indigo were added and heated under reflux for 10 hours under a nitrogen atmosphere. After the reaction was completed, 500 parts of methanol were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 42.1 parts of compound (5). In a four-neck flask, 10 parts of compound (5), 9.8 parts of zinc acetate dihydrate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered and washed with 500 parts of methanol, and the solid content was dried to obtain 8.1 parts of indigo composition (A-3). n was 1 to 5 on the MALDI TOF-MS spectrum, and the maximum absorption wavelength was 840 nm.

[0076] (Production of indigo compound (A-4)) [ka]

[0077] In a four-neck flask, 55.7 parts of compound (4), 120 parts of bromobenzene, and 47 parts of diazabicyclooctane were added and stirred for 20 minutes. Then, 39.7 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25.0 parts of 6,6-difluoroindigo were added and heated under reflux for 10 hours under a nitrogen atmosphere. After the reaction was completed, 500 parts of methanol were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 42 parts of compound (6). In a four-neck flask, 13.5 parts of compound (6), 8.2 parts of zinc (II) acetylacetonate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered and washed with 500 parts of methanol, and the solid content was dried to obtain 9.7 parts of indigo compound (A-4). The maximum absorption wavelength was 845 nm.

[0078] (Production of indigo compound (A-5)) [ka]

[0079] In a four-neck flask, 25 parts of 6,6-dibromoindigo, 32.7 parts of phenoxazine, 77.6 parts of cesium carbonate, 1.4 parts of tris(dibenzylideneacetone)dipalladium(0), 1.4 parts of XPhos, and 120 parts of toluene were added and heated under reflux for 10 hours. After the reaction was completed, 100 parts of hexane were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 23.8 parts of compound (7). In a four-neck flask under a nitrogen atmosphere, 17.2 parts of 2-naphthylamine, 120 parts of bromobenzene, and 22.4 parts of diazabicyclooctane were added and stirred. Then, 19 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 22.1 parts of compound (7) were added and heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 22.1 parts of compound (8). In a four-neck flask, 13.5 parts of compound (8), 7.7 parts of palladium acetylacetonate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered and washed with 500 parts of methanol, and the solid content was dried to obtain 9.0 parts of indigo compound (A-5). The maximum absorption wavelength was 940 nm.

[0080] (Production of indigo compound (A-6)) [ka]

[0081] In a four-neck flask, 25 parts of 6,6-dibromoindigo, 30.2 parts of diphenylamine, 77.6 parts of cesium carbonate, 1.4 parts of tris(dibenzylideneacetone)dipalladium(0), 1.4 parts of XPhos, and 120 parts of toluene were added and heated under reflux for 10 hours. After the reaction was completed, 100 parts of hexane were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 24.9 parts of compound (9). In a four-neck flask under a nitrogen atmosphere, 15.2 parts of 3,5-dimethylaniline, 120 parts of bromobenzene, and 23.5 parts of diazabicyclooctane were added and stirred. Then, 19.9 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25 parts of compound (9) were added and heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 23.6 parts of compound (10). In a four-neck flask, 10 parts of compound (10), 7.0 parts of cobalt acetylacetonate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered, washed with 500 parts of methanol, and dried to obtain 9.2 parts of indigo compound (A-6). The maximum absorption wavelength was 960 nm.

[0082] (Production of indigo compound (A-7)) [ka]

[0083] In a four-neck flask, 25 parts of 6,6-dibromoindigo, 34.9 parts of 9(10H)-acridone, 77.6 parts of cesium carbonate, 1.4 parts of tris(dibenzylideneacetone)dipalladium(0), 1.4 parts of XPhos, and 120 parts of toluene were added and heated under reflux for 10 hours. After the reaction was completed, 100 parts of hexane were added and filtered to obtain a powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 18.5 parts of compound (11). In a four-neck flask under a nitrogen atmosphere, 22.3 parts of 4-hexoxyaniline, 120 parts of bromobenzene, and 21.6 parts of diazabicyclooctane were added and stirred. Then, 18.3 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25 parts of compound (11) were added and heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 20 parts of compound (12). In a four-neck flask, 10 parts of compound (12), 5.8 parts of zinc (II) acetylacetonate, and 120 parts of tetrahydrofuran were mixed and stirred, and the mixture was heated and stirred at 40°C for 5 hours. The reaction solution was cooled to 30°C while stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered, washed with 500 parts of methanol, and dried to obtain 8.4 parts of indigo compound (A-7). The maximum absorption wavelength was 900 nm.

[0084] (Production of indigo compound (A-8)) [ka]

[0085] In a four-neck flask under a nitrogen atmosphere, 33.4 parts of 3,4-difluoroaniline, 120 parts of bromobenzene, and 48.3 parts of diazabicyclooctane were added and stirred. Then, 40.8 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25 parts of 6-methylindigo were added and the mixture was heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain part of compound (13). In a four-neck flask under a nitrogen atmosphere, 10 parts of compound (13), 13.2 parts of 2-aminoethyl diphenylborinate, and 120 parts of dehydrated tetrahydrofuran were mixed and stirred, and then 9.3 parts of titanium tetrachloride were added dropwise. After the dropwise addition, the mixture was heated under reflux for 2 hours. The reaction solution was cooled to 30°C while still stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered, washed with 500 parts of methanol, and dried to obtain 12.3 parts of indigo compound (A-8). The maximum absorption wavelength was 1030 nm.

[0086] (Production of indigo compound (A-9)) [ka]

[0087] In a four-neck flask, 25 parts of 6,6-dibromoindigo, 29.5 parts of morpholine, 77.6 parts of cesium carbonate, 1.4 parts of tris(dibenzylideneacetone)dipalladium(0), 1.4 parts of XPhos, and 120 parts of toluene were added and heated under reflux for 10 hours. After the reaction was completed, 100 parts of hexane were added and filtered to obtain a powder. This was separated with dichloromethane and water, and the organic layer was concentrated to obtain 18.5 parts of compound (14). In a four-neck flask under a nitrogen atmosphere, 28.7 parts of 2-hexoxyaniline, 120 parts of bromobenzene, and 32.4 parts of diazabicyclooctane were added and stirred. Then, 27.4 parts of titanium tetrachloride were added dropwise. After stirring for 30 minutes, 25 parts of compound (14) were added and heated under reflux for 10 hours. After the reaction was completed, methanol was added and the mixture was filtered to obtain a green powder. This was separated into dichloromethane and water, and the organic layer was concentrated to obtain 26.5 parts of compound (15). In a four-neck flask under a nitrogen atmosphere, 10 parts of compound (15), 9.3 parts of 2-aminoethyl diphenylborinate, and 120 parts of dehydrated tetrahydrofuran were mixed and stirred, and then 6.5 parts of titanium tetrachloride were added dropwise. After the dropwise addition, the mixture was heated under reflux for 2 hours. The reaction solution was cooled to 30°C while still stirring, and poured into 500 parts of methanol while stirring to obtain a slurry. This slurry was filtered, washed with 500 parts of methanol, and dried to obtain 10.3 parts of indigo compound (A-9). The maximum absorption wavelength was 1100 nm.

[0088] (Comparative compound 1) Diimonium dye (CIR-108X) manufactured by Nippon Carlit Co., Ltd. (maximum absorption wavelength is 1070 nm)

[0089] <Production of near-infrared absorbing organic semiconductor ink> [Example 1] (Near-infrared absorbing organic semiconductor ink (D-1)) A mixture of the following composition was added to a mayonnaise bottle, stirred and mixed at 60° C. for 4 hours, and then filtered through a 0.5 μm filter to prepare a near-infrared absorbing organic semiconductor ink. As the p-type organic semiconductor compound (B-1) and the n-type organic semiconductor compound (C-1), the compounds given as specific examples of the p-type organic semiconductor compound (B) and the n-type organic semiconductor compound (C) described above were used. Indigo composition (A-1): 0.04g p-type organic semiconductor compound (B-1): 0.08g n-type organic semiconductor compound (C-1): 0.12g Organic solvent 1: 1-chlorobenzene: 10.0 mL Organic solvent 2: 1,8-diiodooctane: 0.2 mL

[0090] [Examples 2 to 44, Comparative Examples 1 to 4] (Near infrared absorbing organic semiconductor ink (D-2)~(D-48)) The following near-infrared absorbing organic semiconductor inks (D-2) to (D-48) were prepared in the same manner as the near-infrared absorbing organic semiconductor ink (D-1), except that the indigo composition, indigo compound or comparative compound, p-type organic semiconductor compound, n-type organic semiconductor compound, and organic solvent were changed to the compositions and amounts shown in Table 1. As the p-type organic semiconductor compounds (B-1) to (B-4) and the n-type organic semiconductor compounds (C-1) to (C-4), the compounds given as specific examples of the p-type organic semiconductor compound (B) and the n-type organic semiconductor compound (C) described above were used.

[0091] [Table 1]

[0092] <Manufacture of near-infrared absorbing organic semiconductor devices> [Example 100] (Near-infrared absorbing organic semiconductor device (E-1)) The glass substrate with the ITO film patterned was ultrasonically cleaned with toluene, acetone, ultrapure water, and isopropyl alcohol for 20 minutes each, and then placed in a plasma cleaner to clean the substrate surface for 20 minutes. Next, after irradiating with ozone UV for 30 minutes, a PEDOT:PSS thin film was formed as an electron blocking layer with a thickness of 60 nm using a spin coater, and then heat-treated at 120°C for 30 minutes. Next, the near-infrared absorbing organic semiconductor ink (D-1) was applied using a spin coater so as to give a film thickness of 100 nm, and then heat-treated at 150°C for 10 minutes to form a near-infrared absorbing organic semiconductor layer and obtain a laminate. Thereafter, using a small high vacuum deposition apparatus, the prepared laminate was placed on a mask in the high vacuum deposition apparatus, and Ca (20 nm) was sequentially deposited as a hole blocking layer and an Al layer (80 nm) as a positive electrode to prepare a near infrared absorbing organic semiconductor device (E-1).

[0093] [Examples 101 to 143, Comparative Examples 100 to 103] (Near-infrared absorbing organic semiconductor devices (E-2)~(E-48)) Next, near-infrared absorbing organic semiconductor devices (E-2) to (D-48) were prepared in the same manner as the near-infrared absorbing organic semiconductor device (E-1), except that the near-infrared absorbing organic semiconductor ink was changed to the composition shown in Table 2.

[0094] [Example 200] (Near-infrared absorbing organic semiconductor device (F-1)) The glass substrate with the patterned ITO film was ultrasonically cleaned with toluene, acetone, ultrapure water, and isopropyl alcohol for 20 minutes each, then placed in a plasma cleaner and the substrate surface was cleaned with plasma for 20 minutes. Next, after irradiating with ozone UV for 30 minutes, a hole blocking layer was formed with Avantama-N10 (ZnO, 2.5wt% isopropanol dispersion) to a thickness of 60nm using a spin coater, and heat-treated at 90℃ for 30 minutes. Next, the near-infrared absorbing organic semiconductor ink (D-1) was applied using a spin coater so as to give a film thickness of 100 nm, and then heat-treated at 150°C for 10 minutes to form a near-infrared absorbing organic semiconductor layer and obtain a laminate. Then, using a small high vacuum deposition apparatus, the prepared laminate was placed on a mask in the high vacuum deposition apparatus, and MoO3 (10 nm) was sequentially deposited as an electron blocking layer and an Au layer (80 nm) as a negative electrode to prepare a near-infrared absorbing organic semiconductor device (F-1).

[0095] [Examples 201 to 243, Comparative Examples 200 to 203] (Near-infrared absorbing organic semiconductor devices (F-2)~(F-48)) Next, near-infrared absorbing organic semiconductor devices (F-2) to (F-48) were prepared in the same manner as for the near-infrared absorbing organic semiconductor device (F-1), except that the near-infrared absorbing organic semiconductor ink was changed to the composition shown in Table 3.

[0096] [Table 2]

[0097] [Table 3]

[0098] <Evaluation of near-infrared absorbing organic semiconductor devices as photodetectors> (External quantum efficiency (EQE) evaluation) The current-voltage was measured in order to use the obtained near-infrared absorbing organic semiconductor device as a photoelectric conversion element. The external quantum efficiency (EQE) at 940 nm when a bias of 1 V was applied was measured. The EQE of the examples and comparative examples was evaluated by calculating a relative EQE from the following formula. A value of 2 or more can be used without any problems in practical use. The results are shown in Tables 4-1 and 4-2. [Relative EQE of Examples 100 to 110] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 100) × 100 [Relative EQE of Examples 111 to 121] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 101) × 100 [Relative EQE of Examples 122 to 132] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 102) × 100 [Relative EQE of Examples 133 to 143] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 103) × 100 [Relative EQE of Examples 200 to 210] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 200) × 100 [Relative EQE of Examples 211 to 221] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 201) × 100 [Relative EQE of Examples 222 to 232] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 202) × 100 [Relative EQE of Examples 233 to 243] Relative EQE = (EQE of Example) ÷ (EQE of Comparative Example 203) × 100 3: Relative EQE is 101.5% or more 2: Relative EQE is 100.5% or more and less than 101.5% 1: Relative EQE < 100.5%

[0099] [Table 4-1]

[0100] [Table 4-2]

[0101] The results in Tables 4-1 and 4-2 reveal that, regardless of the type of p-type or n-type organic semiconductor and the device configuration, Examples 100 to 143 and 200 to 243 have superior relative EQE at 940 nm to the comparative examples.

[0102] (Heat resistance test) As a heat resistance test for the obtained near infrared absorbing organic semiconductor devices (F-1) to (F-48), they were additionally heated at 130°C for 12 hours, and then the current-voltage was measured. The external quantum efficiency (EQE) at 940 nm was measured when a bias of 1 V was applied. From the EQE values ​​before and after this additional heating, the residual rate was calculated using the following formula to evaluate the heat resistance. A value of 2 or more means that the device can be used without any problems in practical use. The results are shown in Table 5. Residual rate = (EQE after additional heating) ÷ (EQE before additional heating) × 100 3: Survival rate is 90% or more 2: Residual rate is 85% or more but less than 90% 1: Residual rate is less than 85%

[0103] (Lightfastness Test Evaluation) An ultraviolet ray cut filter ("COLOREDOPTICAL GLASS L38" manufactured by HOYA CORPORATION) was attached to the obtained near-infrared absorbing organic semiconductor device substrate, and the substrate was subjected to a light resistance test at 470 W / m 2 After leaving the sample exposed to ultraviolet light for 24 hours using a xenon lamp, the current-voltage was measured. The external quantum efficiency (EQE) at 940 nm was measured when a bias of 1 V was applied. The residual rate was calculated from the EQE values ​​before and after the light fastness test using the following formula to evaluate the light fastness. A value of 2 or higher indicates practical use without any problems. The results are shown in Table 5. Residual rate = (EQE after light resistance test) ÷ (EQE before light resistance test) × 100 3: Survival rate is 90% or more 2: Residual rate is 85% or more but less than 90% 1: Residual rate is less than 85%

[0104] (Weather resistance test evaluation) An ultraviolet ray cut filter ("COLORED OPTICAL GLASS L38" manufactured by Hoya) was attached to the obtained near-infrared absorbing organic semiconductor device substrate, and the substrate was subjected to an accelerated weather resistance test at 900 W / m using an ultra-accelerated weather resistance tester (Iwasaki Electric Co., Ltd., iSuper Xenon Tester SUV-W151). 2 After leaving it under these conditions for 48 hours (two cycles of 12 hours day and night), the current-voltage was measured. The external quantum efficiency (EQE) at 940 nm when a bias of 1 V was applied was measured. From the EQE values ​​before and after the weather resistance test, the residual rate was calculated using the following formula to evaluate the light resistance. A value of 2 or higher indicates practical use without any problems. The results are shown in Table 5. Residual rate = (EQE after weather resistance test) ÷ (EQE before weather resistance test) × 100 3: Survival rate is 90% or more 2: Residual rate is 85% or more but less than 90% 1: Residual rate is less than 85%

[0105] [Table 5]

[0106] From the results in Table 5, it was found that Examples 300 to 343 were superior in heat resistance, light resistance, and weather resistance to the comparative examples, regardless of the type of p-type organic semiconductor or n-type organic semiconductor.

Claims

1. A near-infrared absorbing organic semiconductor ink comprising an indigo compound (A) represented by the following general formula (1), (2), or (3), a p-type organic semiconductor compound (B), an n-type organic semiconductor compound (C), and an organic solvent: 【Chemistry 1】 [X １ ~X ５２ each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent, an arylalkyl group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, an amino group, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, a heterocycle which may have a substituent, a cyano group, or a halogen atom. １ ~X ３６ Two adjacent groups among the groups represented by the formula (I) may be linked to form a ring structure together with the carbon atoms to which they are bonded. １ ~M ２ each independently represents Zn, Co, Ni, or Pd. n represents the degree of polymerization and is 0 to 8.

2. 2. The near infrared absorbing organic semiconductor ink according to claim 1, further comprising 1,8-diiodooctane or 1-chloronaphthalene as an additive.

3. A film formed from the near-infrared absorbing organic semiconductor ink according to claim 1 or 2.

4. A near-infrared absorbing organic semiconductor device comprising the film according to claim 3.

5. A near-infrared absorbing organic semiconductor device, wherein a photoelectric conversion layer is the film according to claim 3.

6. A near-infrared absorbing organic photodetector comprising the near-infrared absorbing organic semiconductor device according to claim 5 .

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