Photosensitive resin composition, method for producing a photosensitive resin composition

Abstract

To provide a photosensitive resin composition that can be repurposed as a photoresist and facilitates the formation of a high-resolution wavelength conversion layer. [Solution] A photosensitive resin composition comprising a solvent, a photopolymerizable compound, photoresponsive particles having a perovskite-type crystalline structure, ligands coordinating to the photoresponsive particles, an organic acid, an amine, and an amide compound, wherein the ratio of the total content of the organic acid, amine, and amide compound to the content of the photopolymerizable compound is 2.0% by weight or less.

Description

[Technical Field]

[0001] This invention relates to a photosensitive resin composition and a method for producing a photosensitive resin composition. [Background technology]

[0002] In recent years, there has been research into applying quantum dots as wavelength conversion materials to display elements. One proposed display element using quantum dots is a color filter that has a wavelength conversion layer containing quantum dots between partitions on an organic light-emitting pixel array, which is the light source. In this color filter with a wavelength conversion layer, wavelength conversion layers containing quantum dots with different emission wavelengths due to wavelength conversion are arranged adjacent to each pixel region. The wavelength conversion layer containing quantum dots is formed by curing an ink made of a photocurable composition. Patent Document 1 discloses a photocurable ink using a perovskite compound dispersed in a dry manner. Patent Document 2 discloses a photocurable composition in which fluorescent particles containing a perovskite compound are dispersed in a photopolymerizable compound with ligands such as phosphoric acid compounds and carboxylic acid compounds. Furthermore, Patent Document 2 discloses an inkjet ink that uses a photocurable composition as the ink and to which a surfactant is added in order to adjust the surface tension and ensure the wettability of the ink on the printing substrate. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-45491 [Patent Document 2] Japanese Patent Publication No. 2020-70444 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, as light-emitting pixels become more detailed, inkjet methods require even smaller ink droplets. This miniaturization significantly reduces the accuracy of ink droplet placement, making the formation of wavelength conversion layers in the desired layout not always easy. Photolithography offers a simple and high-resolution formation method.

[0005] However, in order to convert these inks into photoresists that can be patterned using photolithography, the perovskite compound must be dispersible in a photopolymerizable compound soluble in the developer. Furthermore, a high solubility contrast in the developer is required between the photosensitive and non-photosensitive areas, and the generation of development residue raises concerns about reduced reliability of element adhesion on the residue and a decrease in the quality of the light-emitting display due to scattering, thus requiring many improvements. The present invention has been made in view of such background art, and aims to provide a photosensitive resin composition that can be converted into a photoresist and facilitates the formation of a high-definition wavelength conversion layer. [Means for solving the problem]

[0006] A photosensitive resin composition according to an embodiment of the present invention comprises a solvent, a photopolymerizable compound, photoresponsive particles having a perovskite-type crystalline structure, a ligand that at least a portion of which coordinates to the photoresponsive particles, an organic acid, an amine, and an amide compound derived from at least one of the organic acid and the amine, wherein the ratio of the total content of the organic acid, the amine and the amide compound to the content of the photopolymerizable compound is 2.0% by weight or less.

[0007] Furthermore, a method for producing a photosensitive resin composition according to an embodiment of the present invention comprises the steps of: preparing a mixed solution containing a solvent, photoresponsive particles having a perovskite-type crystalline structure, ligands coordinating to the photoresponsive particles, an organic acid, an amine, and an amide compound; and selectively reducing at least one of the organic acid, the amine, and the amide compound from the mixed solution so as to reduce the total content of the organic acid, the amine, and the amide compound in the mixed solution. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a photosensitive resin composition that can be repurposed as a photoresist and facilitates the formation of a high-resolution wavelength conversion layer. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below.

[0010] The photosensitive resin composition according to an embodiment of the present invention comprises a solvent, a photopolymerizable compound, photoresponsive particles having a perovskite-type crystalline structure, a ligand that at least a portion of which coordinates to the photoresponsive particles, an organic acid, an amine, or an amide compound derived from the organic acid and the amine. Herein, the photosensitive resin composition according to the embodiment satisfies the condition that the ratio of the total content of the organic acid, amine, and amide compound to the content of the photopolymerizable compound is 2.0% by weight or less.

[0011] (Embodiment) <Solvent> The solvent used in this embodiment is used to keep the photosensitive resin composition in a liquid state when using it as a photoresist, and to uniformly coat it onto the substrate. By keeping the photoresist in a liquid state, the solvent makes it possible to form a uniform film of the photosensitive resin composition using spin coating. Therefore, the solvent should be selected from those that can dissolve photopolymerizable compounds.

[0012] Specific examples of solvents used in this embodiment include propylene glycol monomethyl ether acetate, 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 propionate benzyl alcohol, 1,2,3-trichloropropane, 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-methyl-1,3-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-butanone, o-xylene, m-xylene, p-xylene, mesitylene, m-diethylbenzene, m-dichlorobenzene, N,N-dimethylformamide N,N-dimethylacetamide, n-butylbenzene, n-propyl acetate, toluene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene, γ-butyrolactone, propylene carbonate, isobutyl alcohol, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether, ethylene glycol monopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl Examples include diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, methyl isobutyl ketone, methylcyclohexanol diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, cyclohexanol, cyclohexanol acetate, cyclohexanone, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monopropylene ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, benzyl alcohol, propylene glycol diacetate, and the like.

[0013] <Photopolymerizable compound> The photosensitive resin composition according to this embodiment is a resist material in which a photopolymerizable compound and photo-responsive particles having a perovskite crystal structure are dispersed in a solvent, and the photopolymerizable compound containing such photo-responsive particles is developed into a predetermined pattern by a photolithography process. The photopolymerizable compound of this embodiment is configured to include a base polymer having a photopolymerizable crosslinking portion and a photoinitiator. The photopolymerizable compound may further contain a polymerizable crosslinking agent.

[0014] The photopolymerizable compound of this embodiment is preferably alkali-soluble.

[0015] Since the photopolymerizable compound has alkali solubility, a photosensitive resin composition capable of alkali development is obtained. Known methods such as introducing a hydroxyl group and a carboxyl group into the molecule are applied as methods for imparting alkali solubility to the photopolymerizable compound.

[0016] To use the photosensitive resin composition of this embodiment as a photoresist, either a positive type in which the exposed portion is more easily dissolved in the developer than the unexposed portion or a negative type in which the exposed portion is less easily dissolved in the developer than the unexposed portion can be used. However, in the positive type, in a system where patterns of photo-responsive particles having different perovskite crystal structures are successively formed on a substrate by multiple photolithographies, the pattern formed in the first time becomes the exposed portion in the second photolithography. Specifically, when forming a pattern of photo-responsive particles having a perovskite crystal structure that emits red light at a position adjacent to a pattern of perovskite phosphor particles that emit green light, the pattern of photo-responsive particles having a perovskite crystal structure that emits green light becomes the exposed portion. In the above system, since there is concern that it may dissolve in the developer in the positive type, the negative type is preferable. The photoresist of this embodiment refers to one in which the solubility contrast between the exposed portion and the unexposed portion with respect to the developer is 5 or more.

[0017] <Base Polymer of Photopolymerizable Compound> The following compounds can be used as base polymers for the photopolymerizable compounds of this embodiment. The base polymer may be a diisocyanate, a methacrylate or partially acid anhydride modified product thereof of a bisphenol-type epoxy resin, a carboxyl group-containing urethane resin obtained by polyaddition reaction of a carboxyl group-containing dialcohol compound and a diol compound. Furthermore, the base polymer may have an aromatic ring in its molecule. In addition, the base polymer may be a carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with methacrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the hydroxyl group present in the side chain. Furthermore, the base polymer may also have an aromatic ring in its molecule.

[0018] Examples include acrylic acids obtained by copolymerization of unsaturated carboxylic acids such as methacrylic acid with unsaturated group-containing compounds such as styrene, alkyl methacrylate, methylstyrene, and isobutylene, or those having an aromatic ring within the molecule.

[0019] Examples include carboxyl group-containing urethane resins or those having aromatic rings within the molecule, obtained by polyaddition reactions of diol compounds such as polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, bisphenol alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0020] The photopolymerization initiator is appropriately selected according to the wavelength used for exposure. In this embodiment, known photopolymerization initiators can be used. The main active species that initiate the polymerization reaction include radical polymerization initiators that generate radicals and cationic polymerization initiators that generate acids, and these may be used in combination. Examples of photoradical polymerization initiators that generate radicals using active energy rays include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl methyl ketal, ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyloxime)], 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2-benzyl Acetophenones such as -2-dimethylamino-1-(4-morpholinophenyl)butane, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropan-1-one; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; and, but not limited to, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0021] Commercially available photopolymerization initiators can also be used, such as ADEKA's "ADEKA Optomer SP-170," "ADEKA Optomer SP-172," and "SP-150" (product names), Midori Chemical's "BBI-103" and "BBI-102" (product names), Sanwa Chemical's "IBPF," "IBCF," "TS-01," and "TS-91" (product names), Sunapro's "CPI-210," "CPI-300," and "CPI-410" (product names), and BASF Japan's "Irgacure 290" (product name). Two or more of these photopolymerization initiators can also be used in combination.

[0022] Examples of cationic polymerization initiators include oxime sulfonate compounds, sulfonimide compounds, onium salts, diazomethane compounds, halogen-containing compounds, sulfone compounds, sulfonic acid ester compounds, carboxylic acid ester compounds, and quinone diazide compounds. These may be used individually or in combination of two or more.

[0023] For example, (camphorsulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, 2-(octylsulfonyloxyimino)-2-(4-methoxyphenyl)acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, (5-propylsulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, benzothiazonium salt, tetrahydrothiophenium salt, diphenyliodonium salt, triphenylsulfonium salt, sulfonium salt, benzylsulfonium salt, benzylsulfonium salt, 4,7-di-n-butoxy-1-naphthyltetrahydro Thiophenium trifluoromethanesulfonate N-(trifluoromethylsulfonyloxy)succinimide, N-(camphasulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)succinimide, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, N-(camphasulfonyloxy)phthalimide, N-(2-trifluoromethylphenylsulfonyloxy)phthalimide, benzyl-4-hydroxyphen Methylsulfonium hexafluorophosphate, N-(2-trifluoromethylphenylsulfonyloxy)succinimide, N-(4-fluorophenylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(2-fluorophenylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(camphasulfonyloxy)diphenylmaleimide, 4-methylphenylsulfonyloxy)diphenylmaleimide, N-hydroxynaphthalimide-trifluoromethanesulfonic acid ester, tetrahydroxybenzophenone, bis(p-hydroxyphenyl)methane, tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyphenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,3,4-trihydroxyphenyl)propane, 1,1,3-tris(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropane, 4,Examples include, but are not limited to, 4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol, bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, 3,3,3',3'-tetramethyl-1,1'-spirovindene-5,6,7,5',6',7'-hexanol, and 2,2,4-trimethyl-7,2',4'-trihydroxyflavan.

[0024] The photopolymerizable compound applied to the photosensitive resin composition according to this embodiment is provided in an embodiment that includes an acrylate monomer having at least one of a carboxyl group and a hydroxyl group.

[0025] Compounds capable of photocrosslinking are used as polymerization crosslinking agents. Polymerization initiators include monofunctional acrylate compounds, monofunctional methacrylate compounds, difunctional acrylate compounds, difunctional methacrylate compounds, trifunctional or more functional acrylate compounds, and trifunctional or more functional methacrylate compounds. Additionally, hydroxyl group-containing acrylate compounds, hydroxyl group-containing methacrylate compounds, carboxyl group-containing acrylate compounds, carboxyl group-containing methacrylate compounds, vinyl compounds, and the like can be used as polymerization initiators.

[0026] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, benzyl (meth)acrylate, and 3,3,5-trimethicyl Lucyclohexyl acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, and (3-ethyloxetan-3-yl)methyl (meth)acrylate can be used.

[0027] Examples of difunctional (meth)acrylates that can be used include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 700 di(meth)acrylate, and neopentyl glycol di(meth)acrylate.

[0028] Examples of trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, trimethylolpropane PO-modified tri(meth)acrylate, trimethylolpropane EO-modified tri(meth)acrylate, glycerin propoxy tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, pentaerythritol tri(meth)acrylate, and EO-modified pentaerythritol tetraacrylate. Examples of vinyl compounds include vinyl acetate, vinyl benzoate, vinyl pivalate, vinyl methacrylate, and N-vinylpyrrolidone.

[0029] Cationic polymerizable compounds can be either photopolymerizable or thermally polymerizable. These may be used individually or in combination of two or more types. Typical cationic polymerizable compounds include, for example, epoxy compounds, oxacene compounds, and vinyl ether compounds.

[0030] In this embodiment, commercially available photoresists may be used. For example, "GLR series" from Osaka Organic Chemical Industry Co., Ltd., "Photoclear" from Toray Industries, Ltd., "VPA" from Nippon Steel Chemical & Materials Co., Ltd., and "Acrycure" from Nippon Shokubai Co., Ltd. can be used. Commercially available photoresists contain photopolymerizable compounds, solvents, etc., and the photosensitive resin composition of this embodiment can be prepared by adding photoresponsive particles or ligands that have a perovskite crystal structure.

[0031] <Photoresponsive particles> The photo-responsive particles applied to the photosensitive resin composition according to this embodiment have a perovskite crystal structure, and particulate ones having at least one length of 500 nm or less are adopted. The shape of the photo-responsive particles is a solid particle in which a predetermined geometric form is stably maintained from the viewpoint of the quantum confinement effect, such as a spherical shape, a cube shape, a rod shape, a disk shape, etc. As the photo-responsive particles having a perovskite crystal structure, the components constituting the A site, the B site, and the X site form a crystal structure. The perovskite compound composed of A, B, and X as components is not particularly limited, and may be a compound having any of a three-dimensional structure, a two-dimensional structure, and a pseudo-two-dimensional structure. In the case of a three-dimensional structure, the perovskite compound is represented by ABX3, and in the case of a two-dimensional structure, it is represented by A2BX4.

[0032] Specific examples of the perovskite compound having a three-dimensional structure represented by ABX3 include CsPbBr3, CsPbCl3, CsPbI3, CsPbBr (3-y) I y (0 < y < 3), CsPbBr (3-y) Cl y (0 < y < 3), FAPbBr3, FAPbCl3, FAPbI3, FAPbBr (3-y) I y (0 < y < 3), FAPbBr (3-y) Cly (0 < y < 3), FAPbBr (3-y) Cl y (0 < y < 3) (FA is formamidinium), MAPbBr3, MAPbCl3, MAPbI3, MAPbBr (3-y) I y (0 < y < 3), MAPbBr (3-y) Cl y [[ID=]](0 < y < 3) (MA is methylammonium).

[0033] Preferred specific examples of the perovskite compound having a two-dimensional structure represented by A2BX4 include Cs2PbBr4, Cs2PbCl4, Cs2PbI4, Cs2PbBr (4-y) I y (0 < y < 4), Cs2PbBr (4-y)Cly(0 <y<4)、FA2PbBr4、FA2PbCl4、FA2PbI4、FA2PbBr (4-y) I y (0 <y<4)、FA2PbBr (4-y) Cl y (0 <y<4)、FA2PbBr (4-y) Cl y (0 <y<4)(FAはホルムアミジニウム)、MA2PbBr4、MA2PbCl4、MA2PbI4、MA2PbBr (4-y) I y (0 <y<4)、MA2PbBr (4-y) Cl y (0 <y<4)、(MAはメチルアンモニウム)。

[0034] Furthermore, perovskite compounds doped with Eu, Gd, Yb, Mn, Ce, Bi, Sm, Ho, or Tb may also be used.

[0035] In this specification, photoresponsiveness refers to the ability to absorb excitation light, change its energy level, and emit light of a specific wavelength.

[0036] <ligand> The ligand used in this embodiment coordinates to the photoresponsive particles, at least in part. The ligand enables the dispersion of the photoresponsive particles in a photopolymerizable compound or solvent.

[0037] Examples of ligands include carboxylic acid compounds, phosphoric acid compounds, sulfonic acid compounds, primary to tertiary amine compounds, quaternary ammonium compounds, thiol compounds, and compounds having a zwitterionic moiety. Among these, compounds having a zwitterionic moiety are preferred as ligands.

[0038] Compounds having a zwitterionic moiety can sometimes be described as compounds exhibiting zwitterionic properties.

[0039] The zwitterionic ligand used in this embodiment includes a structural unit represented by at least one of formulas (1) and (2).

[0040] Here, in formulas (1) and (2), R1 independently represents either a hydrogen atom or a methyl group, R2 represents either a hydrogen atom, a carboxyl group, a sulfo group, a phospho group, or a hydroxyl group, A1 represents either a quaternary ammonium cation or a phosphate anion, A2 represents either a sulfonate anion or a carboxylate anion, A3 represents a side chain containing structural units A1 and A2 and exhibiting zwitterionic properties, and k, l, m, and n represent positive real numbers.

[0041] [ka]

[0042] [ka]

[0043] The main chain is formed by direct or indirect linkage between the structural unit represented by formula (1) itself or the structural unit represented by formula (2). In this specification, indirect linkage means linkage via compounds other than the structural units represented by formulas (1) and (2). In this embodiment, the structural unit represented by formula (1) is the first structural unit, the structural unit represented by formula (2) is the second structural unit, and compounds other than these that link are designated as the third structural unit. The third structural unit is provided with functions that are lacking in the first and second structural units, such as solubility, surface tension, and viscosity. Linkage of the third structural unit with the first and second structural units can be easily carried out by copolymerization. Linkage is possible by copolymerizing the following (meth)acrylates. Solubility in the solvent can be adjusted by using monofunctional methacrylates. Examples of monofunctional methacrylates include, but are not limited to, hexyl methacrylate, cyclohexyl acrylate, isoamyl acrylate, isobonyl acrylate, and benzyl methacrylate. For example, surface tension and refractive index can be adjusted by using fluorine-containing acrylates. Examples of fluorine-containing acrylates include, but are not limited to, 2,2,2-trifluoroethyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, 1H,1H,5H-octafluoropentyl acrylate, and 1H,1H,5H-octafluoropentyl methacrylate. Furthermore, the tackiness can be adjusted by using dimer acid esters. Examples of dimer acid esters include, but are not limited to, tetrahydrofurfuryl alcohol acrylic acid polymer ester, ethoxyethoxyethanol acrylic acid polymer ester, and 1,6-hexanediol acrylic acid polymer ester.

[0044] On the other hand, in this specification, a side chain refers to a molecular chain portion that branches off from the main chain. The side chain of formula (1) exhibits zwitterionic properties, and the side chain R2 of the structural unit represented by formula (2) has at least one of carboxy, sulfo, phospho, or hydroxyl in a part of the molecular chain of side chain R2.

[0045] The structural unit represented by formula (1) protects the photoresponsive particles that take on a perovskite crystal structure, while the structural unit represented by formula (2) primarily functions for dispersion in photopolymerizable compounds and developability. Specifically, the zwitterionic portion of the structural unit represented by formula (1) firmly coordinates to the ionic surface of the perovskite, protecting the photoresponsive particles that take on a perovskite crystal structure. The side chain R2 of the structural unit represented by formula (2) functions for affinity with the hydroxyl and carboxyl groups of the base polymer of the photopolymerizable compound, which is introduced for alkali solubility. In this way, the photoresponsive particles that take on a perovskite crystal structure can be dispersed in the base polymer of the photopolymerizable compound by the ligand. Therefore, when the photosensitive resin composition is used as a photoresist, it becomes possible to pattern the photosensitive resin composition in which photoresponsive particles with a perovskite crystal structure are dispersed by photolithography. Furthermore, since the side chain R2 acts as a soluble group in alkaline developer, the generation of ligand-derived development residue is suppressed, resulting in the patterning of photoresponsive particles with a perovskite crystal structure. Therefore, since photoresponsive particles with a perovskite crystal structure that exhibit different emission colors upon wavelength conversion can be patterned on the same plane, it can be used in the manufacture of high-resolution, narrow-pitch wavelength-converting color filters, etc.

[0046] The structural unit represented by formula (1) in this embodiment has a side chain A3 which has a zwitterionic moiety consisting of a combination of A1 and A2. When A1 in side chain A3 is a phosphate anion, A2 becomes a quaternary ammonium cation, and when A1 is a quaternary ammonium cation, A2 becomes a sulfonate anion or a carboxylic acid anion. The zwitterionic moiety can strongly coordinate to the surface of photoresponsive particles that have a perovskite crystal structure. Furthermore, since the ligand of this embodiment has multiple zwitterionic moieties in the same molecule, even if some coordination is detached from the surface of the nanoparticle due to some stimulus, it can be easily re-coordinated.

[0047] The amount of ligands, when the weight of the photoresponsive particles having a perovskite crystal structure is set to 1, is preferably 0.5 to 10, more preferably 0.5 to 4, and even more preferably 0.5 to 3. If the amount of ligands is less than 0.5 or greater than 3, the dispersion stability of the photoresponsive particles having a perovskite crystal structure may be insufficient.

[0048] The copolymerization ratio n / m of the ligand in this embodiment is appropriately selected based on the dispersibility of the photopolymerizable compound and its solubility in solvents and developers. If the copolymerization ratio n / m is too high, dispersibility improves, but solubility in solvents tends to decrease. If the copolymerization ratio n / m is too low, solubility in solvents improves, but dispersibility tends to decrease. The copolymerization ratio n / m is preferably 0.25 to 20, and more preferably 4 to 10. When the copolymerization ratio is within the above range, the ligand coordinates strongly to the photoresponsive particles that take the perovskite crystal structure, and solubility in solvents is easily ensured. The number-average molecular weight of the ligand in this embodiment is preferably 2000 to 50000, and more preferably 5000 to 30000. When the number-average molecular weight of the ligand is within the above range, stability and solubility in polar solvents are easily ensured.

[0049] We will now explain the case where A1 in the side chain A3 of equation (1) is a negatively charged phosphate anion and A2 is a positively charged quaternary ammonium cation.

[0050] In this embodiment, the link between the main chain and the side chain A3, where A1 is a phosphate anion, is an ester bond. In this specification, the link is not limited to an ester bond, but may also be an amide bond, an ether bond, an alkylene bond, or an arylene bond. The alkylene group may be linear or branched, and an alkylene group having 1 to 2 carbon atoms is preferred. Examples of alkylene groups having 1 to 2 carbon atoms include methylene groups and ethylene groups. Examples of arylene groups include 1,2-phenylene groups, 1,3-phenylene groups, 1,4-phenylene groups, naphthalene-1,4-diyl groups, naphthalene-1,5-diyl groups, and naphthalene-2,6-diyl groups. However, ester bonds are preferred from the viewpoint of raw material availability and ease of manufacture. For R1, examples include hydrogen, methyl, ethyl, n-propyl, isopropyl, and n-butyl groups, but from the viewpoint of polymer production (polymerizability), hydrogen atoms and methyl groups are preferred. The value of k in side chain A3 is preferably in the range of 1 to 3 from the viewpoint of raw material availability and ease of manufacturing.

[0051] In a zwitterionic structural unit, the positive and negative charges are located at non-adjacent positions within the same molecule, resulting in a molecule that is chargeless overall. Therefore, the value of l in A3 is preferably in the range of 2 to 4, taking into consideration the availability of raw materials and ease of manufacturing.

[0052] The positively charged quaternary ammonium cation of B is described below. In the quaternary ammonium cation, alkyl groups are bonded to the nitrogen atom, except for the bond to the phosphate anion, forming the quaternary ammonium cation. C1 to C18 alkyl groups are preferred. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, n-octyl, 2-ethylhexyl, dodecyl, and octadecyl groups. These alkyl groups may be further substituted and bonded to each other, forming a ring.

[0053] We will now explain the case in equation (1) where A1 is a positively charged quaternary ammonium cation and A2 is a negatively charged sulfonate anion or carboxylic acid anion.

[0054] In this embodiment, the main chain and the side chain A3 of A1, a quaternary ammonium cation, are linked by an ester bond. In this specification, the linkage is not limited to an ester bond, but may also be an amide bond, an ether bond, an alkylene bond, or an arylene bond. The alkylene group may be linear or branched, and an alkylene group having 1 to 2 carbon atoms is preferred. Examples of alkylene groups having 1 to 2 carbon atoms include methylene groups and ethylene groups. Examples of arylene groups include 1,2-phenylene groups, 1,3-phenylene groups, 1,4-phenylene groups, naphthalene-1,4-diyl groups, naphthalene-1,5-diyl groups, and naphthalene-2,6-diyl groups. However, ester bonds are preferred from the viewpoint of raw material availability and ease of manufacture. For R1, examples include hydrogen, methyl, ethyl, n-propyl, isopropyl, and n-butyl groups, but from the viewpoint of polymer production (polymerizability), hydrogen atoms and methyl groups are preferred. The value of k in side chain A3 is preferably in the range of 1 to 3 from the viewpoint of raw material availability and ease of manufacturing.

[0055] The nitrogen atom of the quaternary ammonium cation is bonded to the aforementioned linking portion, and is bonded to the sulfonate anion by a hydrocarbon chain of 2 ≤ 1 ≤ 4. The remaining two nitrogen atoms of the quaternary ammonium cation are bonded to alkyl groups to form a quaternary ammonium cation. C1 to C18 alkyl groups are preferred. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, n-octyl, 2-ethylhexyl, dodecyl, and octadecyl groups. These alkyl groups may be further substituted and bonded to each other to form a ring.

[0056] The counteranion B in the quaternary ammonium moiety is described as either a sulfonate anion or a carboxylic acid anion. In a zwitterionic structural unit, the positive and negative charges are located at non-adjacent positions within the same molecule, resulting in a zwitterionic structure where the molecule as a whole has no charge. Therefore, the l in C is preferably in the range of 2 to 4, taking into consideration the availability of raw materials and ease of manufacture.

[0057] In this embodiment, the side chain R2 of the structural unit represented by formula (2) has hydrogen or a carboxyl, sulfo, phospho, or hydroxyl group in part of the molecular chain of the side chain R2. The main chain and the side chain molecule R2 are linked by an ester bond. In this specification, the link is not limited to an ester bond, but may also be an amide bond, an ether bond, an alkylene bond, or an arylene bond. The alkylene group may be linear or branched, and an alkylene group having 1 to 2 carbon atoms is preferred. Examples of alkylene groups having 1 to 2 carbon atoms include a methylene group and an ethylene group. Examples of arylene groups include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group. However, ester bonds are preferred from the viewpoint of raw material availability and ease of manufacture. For R1, examples include hydrogen, methyl, ethyl, n-propyl, isopropyl, and n-butyl groups, but from the viewpoint of producing polymeric compounds (polymerizability), hydrogen atoms and methyl groups are preferred.

[0058] By introducing hydrogen to the side chain R2 of the structural unit represented by formula (2), or by introducing carboxy, sulfo, phospho, or hydroxyl into a portion of the molecular chain of side chain R2, the dispersibility in a photopolymerizable compound to which alkali solubility has been conferred is improved. This is because the hydroxyl and carboxyl groups of the photopolymerizable compound introduced for alkali solubility have a high affinity for carboxy, sulfo, phospho, and hydroxyl. As a result, a photosensitive resin composition is formed in which photoresponsive particles with a perovskite crystal structure are dispersed in a photopolymerizable compound. In this way, when the photosensitive resin composition is used as a photoresist, it becomes possible to pattern photoresponsive particles with a perovskite crystal structure. Furthermore, introducing carboxy, sulfo, phospho, or hydroxyl into R2 improves alkali developability and also has the effect of suppressing the generation of development residue derived from ligands.

[0059] In this embodiment, the alkyl group of the molecular chain of the side chain molecule R2 is preferably an alkyl group having 1 to 30 carbon atoms. Examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-decyl group, n-hexadecyl group, octadecyl group, docosyl group, and triacontyl group.

[0060] Examples of aryl groups include phenyl, 1-naphthyl, and 2-naphthyl groups. Examples of carboxylic acid ester groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, octyl, 2-ethylhexyl, dodecyl, octadecyl, docosyl, triacontyl, phenyl, and 2-hydroxyethyl ester groups.

[0061] Examples of carboxylic acid amide groups include amide groups such as N-methylamide, N,N-dimethylamide, N,N-diethylamide, N-isopropylamide, N-tert-butylamide, Nn-decylamide, Nn-hexadecylamide, N-octadecylamide, N-docosylamide, N-triacontilamide, and N-phenylamide. Other substituents may be introduced if any substituent of carboxy, sulfo, phospho, or hydroxy is introduced to a portion of the side chain molecule R2. In this case, examples of substituents that may be substituted include alkoxy groups such as methoxy and ethoxy groups, amino groups such as N-methylamino and N,N-dimethylamino groups, acyl groups such as acetyl groups, and halogen atoms such as fluorine and chlorine atoms. The substituent to be introduced should be selected appropriately depending on the application.

[0062] In a quaternary ammonium cation, alkyl groups are bonded to the nitrogen atom, except at the site of the bond with the phosphate anion, to form a quaternary ammonium cation. C1 to C18 alkyl groups are preferred. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, n-octyl, 2-ethylhexyl, dodecyl, and octadecyl groups. These alkyl groups may be further substituted and bonded to each other, forming a ring.

[0063] In this embodiment, the photosensitive resin composition may be mixed with, if necessary, oxygen scavengers, antioxidants, scattering agents such as titanium dioxide, surfactants, antifungal agents, light stabilizers, and other additives that impart various properties.

[0064] The photosensitive resin composition of this embodiment contains either an organic acid, an amine, or an amide compound derived from these organic acids and amines. The organic acids, amines, and amide compounds derived from these organic acids and amines contained in the photosensitive resin composition are used or produced as by-products during the wet or dry synthesis of photoresponsive particles with a perovskite crystal structure. For example, in the hot injection synthesis of CsPbX3 (X=Br or I) with a perovskite crystal structure, a Cs-oleate precursor is added at high temperature to a solution in which lead halide forms a salt with oleic acid and oleylamine. Oleic acid and oleylamine form a salt with lead halide and dissolve, and also act as dispersion ligands in high-boiling point solvents. For this reason, they are easily included in the photosensitive resin composition and tend to be a source of developing residue. Furthermore, amide compounds are produced as by-products at high temperatures from oleic acid and oleylamine, which also tend to be a source of developing residue.

[0065] Examples of organic acids used in the photosensitive resin composition of this embodiment include oleic acid, palmitoleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, vaccenic acid, octanoic acid, and p-toluenesulfonic acid.

[0066] Examples of amines include laurylamine, myristylamine, palmitylamine, stearylamine, oleylamine, octylamine, 4-aminobiphenyl, and 2-aminobiphenyl.

[0067] As an amide compound, it is produced by the condensation of the above carboxylic acid and the above amine and is included in the photosensitive resin composition.

[0068] The organic acids, amines, and amide compounds that constitute the ligand components each contain a common hydrocarbon chain of formula (3). The inclusion of the hydrocarbon chain of formula (3) improves the dispersibility of the photoresponsive particles, which have a perovskite crystal structure, in the solvent. However, in formula (3), the subscript t is a real number greater than or equal to 7.

[0069] [ka]

[0070] When the photosensitive resin composition of this embodiment is used as a photoresist, the exposure machine used for exposure is not particularly limited, and any known exposure machine can be used. As exposure light, known types such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps (g-line (436nm), h-line (405nm), i-line (365nm)), xenon lamps, YAG lasers, Ar ion lasers, semiconductor lasers, F2 excimer lasers (157nm), ArF excimer lasers (193nm), KrF excimer lasers (248nm) can be used. The exposure light should be appropriately selected according to the photosensitive wavelength of the photosensitive resin composition used. As exposure equipment, projection exposure equipment with a single wavelength light source, such as an i-line exposure stepper or a KrF stepper, or projection exposure equipment with a broad wavelength mercury lamp light source, such as the Mask Aligner MPA-600Super (product name, manufactured by Canon), can be used. There are no particular restrictions on the developer used, but alkaline aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, and tetramethylammonium hydroxide (TMAH) can be used.

[0071] Furthermore, known coating methods such as spin coating, gravure coating, bar coating, spray coating, dip coating, and die coating can be used as coating methods.

[0072] To obtain sufficient luminescence even with a small thickness of the wavelength conversion layer containing photoresponsive particles with a perovskite crystal structure, an effective method is to increase the concentration of photoresponsive particles with a perovskite crystal structure in the photosensitive resin composition. Therefore, in this embodiment, it is preferable that the weight ratio of perovskite-type photoresponsive particles to the photopolymerizable compound is 5% or more. However, it was found that as the concentration of photoresponsive particles with a perovskite crystal structure increases, development residues derived from organic acids, amines, and amide compounds tend to be generated. As a result of diligent research by the inventors, it was found that adjusting the content of these compounds is effective in suppressing development residues. Specifically, the total content of organic acids, amines, and amide compounds is preferably 2.0% by weight or less, and more preferably 1.2% by weight or less, relative to the content of the photopolymerizable compound. By doing so, it was found that the generation of development residues is suppressed even when the photosensitive resin composition is used as a photoresist.

[0073] Even when the weight percentage ratio of photoresponsive particles with a perovskite crystal structure relative to the weight of the photopolymerizable compound increases, the effect of suppressing the generation of development residue is clearly observed. This is because, although organic acids, amines, and amide compounds are insoluble in alkaline developers, adjusting their concentration to 2.0% by weight or less prevents undissolved residue from forming during development.

[0074] In the photosensitive resin composition of this embodiment, the total content of organic acids, amines, and amide compounds is preferably 30% by weight or less, more preferably 10% by weight or less, relative to the ligand content. The total content of organic acids, amines, and amide compounds is adjusted as appropriate to the ligand content, considering the dispersibility of the photoresponsive particles, which have a perovskite-type crystal structure, with the photopolymerizable compound and solvent.

[0075] When the content of organic acids, amines, and amide compounds exceeds 30% by weight, the dispersibility of photoresponsive particles with a perovskite-type crystal structure in photopolymerizable compounds tends to decrease.

[0076] It is preferable that the ratio of the total content of organic acids, amines, amide compounds, and ligands to the content of the perovskite-type photoresponsive particles is 50% by weight or more. If it is less than 50% by weight, the dispersibility of the photoresponsive particles, which have a perovskite-type crystalline structure, in the photopolymerizable compound tends to decrease. The measurement of the content of organic acids, amines, and amide compounds is not particularly limited, but the absorbance may be measured using TG-DTA, NMR, or ultraviolet-visible absorption spectroscopy, and the content may be calculated from the molar absorbance.

[0077] Furthermore, it is preferable that the ratio of the perovskite-type photoresponsive particles to the photopolymerizable compound content be 5% by weight or more, as this provides a superior proportion of the photosensitive resin composition to the components that ensure the functionality of the functional device.

[0078] The method for producing the photosensitive resin composition of this embodiment includes the steps of preparing a solvent, photoresponsive particles having a perovskite-type crystalline structure, ligands that coordinate to the photoresponsive particles, an organic acid, an amine, and an amide compound. The method for producing the photosensitive resin composition of this embodiment further includes the step of selectively reducing at least one of the organic acid, amine, and amide compound so as to reduce the total content of the organic acid, amine, and amide compound in the mixture.

[0079] The method for reducing the content of organic acids, amines, and amide compounds in this embodiment is not particularly limited, but it is preferable to use at least one of the following methods: dialysis, vacuum distillation, or ultrafiltration. Dialysis and ultrafiltration can reduce the content of organic acids, amines, and amide compounds while keeping the photoresponsive particles with a perovskite crystal structure dispersed without agglomerating them. Centrifugal separation may also be used, but there is a concern that ligand detachment may occur from the photoresponsive particles with a perovskite crystal structure due to solvent shock from the centrifugation solvent used to induce precipitation. Therefore, the centrifugation solvent should be appropriately selected from candidate solvents that have little effect on ligand detachment. [Examples]

[0080] The present invention will be described in more detail below with reference to specific examples. The ligands for Examples 1 to 5 and Comparative Examples 1 to 2 are shown in Table 1.

[0081] (Example 1) In this example, CsPbBr3 is used as the photoresponsive particle with a perovskite crystal structure. CsPbBr3 is synthesized by adding a Cs-oleate precursor to a solution in which a salt was formed with oleic acid and oleylamine heated to 185°C using the hot injection method. The weight of the precipitate recovered by centrifugation was 1.1 g, and TG-DTA measurement showed that the ratio of the weight of CsPbBr3 to the total weight of oleic acid, oleylamine, and the amide produced as a by-product from oleic acid and oleylamine was 6:5.

[0082] A copolymer is used in which equimolar amounts of 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate, methacrylic acid, and 2-methoxyethyl methacrylate are used as ligands. The first structural unit is derived from 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate, the second structural unit from methacrylic acid, and the third structural unit from 2-methoxyethyl methacrylate. In this example, the ligand has a carboxyl group where R2 in the ester portion of the linkage is hydrogen.

[0083] Toluene was added to the precipitate recovered by centrifugation to disperse it in toluene, and 0.6 g of ligand equal in weight to CsPbBr3 was added to exchange ligands between oleylamine, which was coordinated to CsPbBr3, and oleic acid.

[0084] In this example, dialysis was used to reduce the content of oleylamine and oleic acid. A dispersion of ligand-exchanged CsPbBr3 was prepared to contain 30 wt% CsPbBr3 and introduced into a dialysis membrane. A Spectra / Pore 7 dialysis membrane with a molecular weight (Da) of 50000 was used. Before use, it was washed with isopropyl alcohol, and then the isopropyl alcohol was replaced with toluene. The outside of the dialysis membrane was immersed in toluene to discharge oleic acid, oleylamine, and amide compounds outside the dialysis membrane. After 72 hours of dialysis, the toluene dispersion of CsPbBr3 in the dialysis membrane was recovered. TG-DTA measurement showed that the total weight of oleic acid, oleylamine, and amide compounds was reduced to 10% of the pre-dialysis weight.

[0085] In this example, a commercially available alkali-developable resist, GLR-A200, manufactured by Osaka Organic Chemical Industry Co., Ltd., is used as the photopolymerizable compound. The resist used in this example contains a base polymer having a photopolymerizable crosslinking portion, a photopolymerization initiator, and propylene glycol monomethyl ether acetate as a polymerizable crosslinking agent and solvent. The photopolymerizable compound is present in this resist at a weight of 44%.

[0086] A toluene dispersion of dialyzed CsPbBr3 was added to the resist while stirring. The photosensitive resin composition was prepared by adding CsPbBr3 until its content reached 10 wt% relative to the weight of the photopolymerizable compound. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of the photopolymerizable compound was 0.45% by weight. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of ligands was 9.1% by weight. The ratio of the total content of oleic acid, oleylamine, amide compounds, and ligands to the content of perovskite-type photoresponsive particles was 91.6% by weight. The solvents for the photosensitive resin composition were propylene glycol monomethyl ether acetate and toluene. The photoresponsive particles, which have a perovskite-type crystalline structure, dispersed well in the base polymer, and no precipitation occurred in the photosensitive resin composition.

[0087] A photosensitive resin composition is applied to a 4-inch diameter glass substrate by spin coating at 1000 rpm for 20 minutes. Bake in a nitrogen oven at 90°C for 80 seconds.

[0088] Photolithography is performed as follows: A photomask is used in which an 8×28μm non-light-shielding pattern is arranged in an array at a 30μm pitch. The photomask is placed on a photosensitive resin composition on a glass substrate and exposed to an exposure dose of 90mJ / cm2, revealing a latent image pattern of 8×28μm arranged at a 30μm pitch on the photosensitive resin composition. A 0.05wt% potassium hydroxide aqueous solution is used as the developer, and the material is developed for 60 seconds, followed by rinsing with pure water for 30 seconds. An array-like pattern with a thickness of 5μm and arranged at a 30μm pitch of 8×28μm is formed on the glass substrate. The unexposed areas between the patterns are dissolved by the developer, exposing the surface of the glass substrate, and no development residue is observed. When blue light from a light-emitting diode with a maximum peak wavelength of 445nm is transmitted, green fluorescence with a peak emission wavelength of 520nm, PLQY 70%, and FWHM 20nm is observed from the array-like pattern.

[0089] (Example 2) In this example, the photoresponsive particles having a perovskite-type crystal structure are the same as in Example 1, except that CsPb(Br / I)3 synthesized at room temperature is used, and octanoic acid and octylamine are used.

[0090] The weight of the precipitate recovered by centrifugation was 1.0 g, and TG-DTA measurement showed that the ratio of the weight of CsPb(Br / I)3 to the total weight of octanoic acid and octylamine was 5:5.

[0091] A copolymer is used in which 3-[[2-(acryloyloxy)ethyl]dimethylammonio]propane-1-sulfonic acid, methacrylic acid, and 2-methoxyethyl methacrylate are each used in equimolar amounts as ligands.

[0092] Toluene was added to the precipitate recovered by centrifugation to disperse it in toluene, and 0.242 g of ligand (half the weight of CsPb(Br / I)3) was added to exchange ligands with octanoic acid and octylamine that were coordinated to CsPb(Br / I)3.

[0093] In this example, reduced-pressure distillation was used as a method to reduce the content of octanoic acid and octylamine.

[0094] The mixture was placed in a rotary evaporator and depressurized using a rotary pump. The total weight measured by TG-DTA was reduced to 30% of the weight before depressurization.

[0095] In this example, the same commercially available alkali-developable resist as in Example 1 is used as the photopolymerizable compound.

[0096] After removing under reduced pressure, toluene was added to prepare a toluene dispersion of CsPb(Br / I)3, which was then added to the resist while stirring. CsPb(Br / I)3 was added until it reached 5.5 wt% relative to the weight of the photopolymerizable compound, thereby preparing a photosensitive resin composition. The ratio of the total content of octanoic acid and octylamine to the content of the photopolymerizable compound was 1.65% by weight.

[0097] The combined content of octanoic acid and octylamine is 30% by weight relative to the ligand content.

[0098] The ratio of the total content of octanoic acid, octylamine, and ligands to the content of perovskite-type photoresponsive particles is 130% by weight.

[0099] The ligand in this example has a hydroxyl group at the end of the linear chain of R2. The photoresponsive particles, which have a perovskite-type crystalline structure, disperse well in the base polymer and do not precipitate in the photosensitive resin composition. A glass substrate with an array-like pattern of 8 × 28 μm thickness and a 30 μm pitch, as in Example 1, was spin-coated and photolithography was performed as follows. Similar to Example 1, a photomask with 8 × 28 μm non-shielding patterns arranged at a 30 μm pitch was used as the photomask. After alignment so that the non-shielding patterns were adjacent to the pattern formed in Example 1 at a 1 μm interval, exposure was performed. After development and rinsing, a pattern was formed at a position 1 μm away from the pattern formed in Example 1. When blue light-emitting diode light with a maximum peak wavelength of 445 nm was transmitted, a pattern exhibiting red fluorescence with an emission peak wavelength of 623 nm and an FWHM of 34 nm was observed next to the green fluorescence of the pattern formed in Example 1.

[0100] (Example 3) In this example, CsPbBr3 synthesized by the hot injection method, similar to Example 1, was used, and the weight of the precipitate recovered by centrifugation of CsPbBr3 was 1.1 g. The ratio of the total weight of oleic acid, oleylamine, and the amide produced as a by-product from oleic acid and oleylamine was 6:5.

[0101] In this example, equimolar copolymers of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate, 2-hydroxyethyl methacrylate, and methyl methacrylate were used as ligands. Toluene was added to the precipitate recovered by centrifugation to disperse it in toluene, and 0.6 g of ligands equal in weight to CsPbBr3 were added to exchange ligands between oleylamine, which was coordinated to CsPbBr3, and oleic acid.

[0102] In this example, ultrafiltration was used to reduce the content of oleylamine and oleic acid. A dispersion of ligand-exchanged CsPbBr3 was prepared so that the CsPbBr3 content was 5 wt%, and then placed into an ultrafiltration membrane. A WINSEP UF30-0L (Unitika) ultrafiltration membrane was used. After ultrafiltration, the total weight of oleic acid, oleylamine, and amide compounds was reduced to 8.58% of the weight before ultrafiltration. In this example, the same commercially available alkali-developable resist as in Example 1 was used as the photopolymerizable compound. A toluene dispersion of ultrafiltered CsPbBr3 was added to the resist while stirring until the CsPbBr3 content reached 27 wt% relative to the weight of the photopolymerizable compound, thereby preparing a photosensitive resin composition. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of the photopolymerizable compound was 1.95% by weight. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of ligands was 7.8% by weight. The ratio of the total content of oleic acid, oleylamine, amide compounds, and ligands to the content of perovskite-type photoresponsive particles is 108% by weight.

[0103] The photosensitive resin composition of this example was patterned using photolithography without any development residue, similar to Example 1, and the pattern exhibited green fluorescence upon wavelength conversion.

[0104] (Example 4) In this embodiment, FAPbBr3 is used as a photoresponsive particle with a perovskite-type crystal structure. The photosensitive resin composition of this example is the same as that of Example 1, except that a copolymer was used in which only 2-methoxyethyl methacrylate was used in 1.5 times the molar amount of the ligand. The photosensitive resin composition of this example was also patterned by photolithography without any development residue, similar to Example 1, and green fluorescence was confirmed in the pattern after wavelength conversion.

[0105] (Example 5) In this example, the ratio of the total content of octanoic acid and octylamine to the total content of the photopolymerizable compound is 1.65% by weight.

[0106] The combined content of octanoic acid and octylamine is 0.82% by weight relative to the ligand content.

[0107] The ratio of the total content of octanoic acid, octylamine, and ligands to the content of perovskite-type photoresponsive particles is 50.4% by weight. The photosensitive resin composition of this example was patterned without development residue by photolithography, similar to Example 2, and red fluorescence was confirmed in the pattern by wavelength conversion.

[0108] (Comparative Example 1) In this example, CsPbBr3 synthesized by the hot injection method was used, similar to Example 1, and the weight of the precipitate recovered by centrifugation of CsPbBr3 was 1.1 g. The ratio of the total weight of oleic acid, oleylamine, and the amide produced as a by-product from oleic acid and oleylamine was 6:5. The same ligand as in Example 1 was used, and toluene was added to the precipitate recovered by centrifugation to disperse it in toluene. By adding 0.6 g of ligand, equal to the weight of CsPbBr3, the oleylamine and oleic acid that were coordinated to CsPbBr3 were exchanged as ligands. In this comparative example, the content of oleylamine and oleic acid was reduced and used as is, unlike in Example 1.

[0109] In this comparative example, the same commercially available alkali-developable resist as in Example 1 is used as the polymerizable compound.

[0110] A photosensitive resin composition was prepared by adding a toluene dispersion of CsPbBr3 to a resist while stirring until the amount of CsPbBr3 reached 10 wt% relative to the weight of the photopolymerizable compound. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of the photopolymerizable compound was 9.1% by weight. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of ligands was 9.1% by weight. The ratio of the total content of oleic acid, oleylamine, amide compounds, and ligands to the content of perovskite-type photoresponsive particles was 19.1% by weight. When the photosensitive resin composition of this comparative example was developed by photolithography in the same manner as in Example 1, development residue was observed in the unexposed areas.

[0111] (Comparative Example 2) In this comparative example, CsPbBr3 synthesized by the hot injection method was used, similar to Example 1, and the weight of the precipitate recovered by centrifugation of CsPbBr3 was 1.1 g. The ratio of the total weight of oleic acid, oleylamine, and the amide produced as a by-product from oleic acid and oleylamine was 6:5. The same ligand as in Example 1 was used, and toluene was added to the precipitate recovered by centrifugation to disperse it in toluene. Ligand exchange was performed by adding 0.6 g of ligand, equal to the weight of CsPbBr3, to exchange the oleylamine and oleic acid that were coordinated to CsPbBr3. In this comparative example, dialysis was used as a method to reduce the content of oleylamine and oleic acid, similar to Example 1. A dispersion of ligand-exchanged CsPbBr3 was prepared so that the CsPbBr3 content was 30 wt%, and it was placed in a dialysis membrane for 7 hours. After dialysis, the toluene dispersion of CsPbBr3 in the dialysis membrane was recovered. TG-DTA measurement showed that the total weight of oleic acid, oleylamine, and amide compounds was reduced to 27.5% of the pre-dialysis weight. In this comparative example, the same commercially available alkali-developable resist as in Example 1 was used as the polymerizable compound.

[0112] A photosensitive resin composition was prepared by adding a toluene dispersion of CsPbBr3 to a resist while stirring until the amount of CsPbBr3 reached 10 wt% relative to the weight of the photopolymerizable compound. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of the photopolymerizable compound was 2.5% by weight. The ratio of the total content of oleic acid, oleylamine, and amide compounds to the content of ligands was 25% by weight. The ratio of the total content of oleic acid, oleylamine, amide compounds, and ligands to the content of perovskite-type photoresponsive particles was 125% by weight.

[0113] When the photosensitive resin composition of this comparative example was developed by photolithography in the same manner as in Example 1, development residue was observed in the unexposed areas.

[0114] [Table 1]

Claims

1. A photosensitive resin composition comprising a solvent, a photopolymerizable compound, photoresponsive particles having a perovskite-type crystalline structure, a ligand that at least partly coordinates to the photoresponsive particles, an organic acid, an amine, and an amide compound derived from at least one of the organic acid and the amine, wherein the ratio of the total content of the organic acid, the amine, and the amide compound to the content of the photopolymerizable compound is 2.0% by weight or less.

2. The photosensitive resin composition according to claim 1, wherein the ligand comprises a structural unit represented by at least one of formula (1) and formula (2). Here, in formulas (1) and (2), R1 independently represents either a hydrogen atom or a methyl group, R2 represents either a hydrogen atom, a carboxyl group, a sulfo group, a phospho group, or a hydroxyl group, A1 represents either a quaternary ammonium cation or a phosphate anion, A2 represents either a sulfonate anion or a carboxylate anion, A3 represents a side chain containing structural units A1 and A2 and exhibiting zwitterionic properties, and k, l, m, and n represent positive real numbers. 【Chemistry 1】 【Chemistry 2】

3. The photosensitive resin composition according to claim 1 or 2, wherein the ligand comprises a hydrocarbon chain represented by formula (3). 【Transformation 3】 In equation (3), t represents a real number greater than or equal to 7.

4. The photosensitive resin composition according to claim 3, wherein at least one of the organic acid, the amine, and the amide compound comprises the hydrocarbon chain.

5. The photosensitive resin composition according to claim 1 or 2, wherein the ratio of the total content of the organic acid, the amine, and the amide compound to the content of the ligand is 30% by weight or less.

6. The photosensitive resin composition according to claim 1 or 2, wherein the ratio of the total content of the organic acid, the amine, the amide compound, and the ligand to the content of the perovskite-type photoresponsive particles is 50% by weight or more.

7. The photosensitive resin composition according to claim 1 or 2, wherein the ratio of the content of the perovskite-type photoresponsive particles to the content of the photopolymerizable compound is 5% by weight or more.

8. The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerizable compound is alkali soluble.

9. The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerizable compound comprises an acrylate monomer having at least one of a carboxyl group and a hydroxyl group.

10. A method for producing a photosensitive resin composition, comprising the steps of: preparing a mixture containing a solvent, photoresponsive particles having a perovskite-type crystalline structure, ligands that coordinate to the photoresponsive particles, an organic acid, an amine, and an amide compound; and selectively reducing at least one of the organic acid, the amine, and the amide compound from the mixture so as to reduce the total content of the organic acid, the amine, and the amide compound in the mixture.

11. The method for producing a photosensitive resin composition according to claim 10, wherein the reduction step includes at least one of dialysis, vacuum distillation, and ultrafiltration.

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