Semiconductor nanoparticle composite, semiconductor nanoparticle composite dispersion, semiconductor nanoparticle composite composition, semiconductor nanoparticle composite cured film, and semiconductor nanoparticle composite patterned film

Abstract

To provide a semiconductor nanoparticle complex which can be dispersed in a dispersion medium in a high concentration and has a high efficiency of fluorescence quantum.SOLUTION: The semiconductor nanoparticle complex according to the present invention is a semiconductor nanoparticle complex in which ligand is arranged on a surface of a semiconductor nanoparticle. The ligand contains an organic group and a coordinating group. The organic group has one or more groups selected from an ether group, an ester group, and an amido group. A molecular weight of the ligand is 50 or more and 600 or less. A mass ratio of the ligand to the semiconductor nanoparticle (ligand / semiconductor nanoparticle) is in a range of 0.05 to 0.50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, a semiconductor nanoparticle composite cured film, and a semiconductor nanoparticle composite patterned film. This application claims priority based on Japanese Patent Application No. 2019-103243 filed on May 31, 2019, Japanese Patent Application No. 2019-103244 filed on the same day, Japanese Patent Application No. 2019-103245 filed on the same day, and Japanese Patent Application No. 2019-103246 filed on the same day, and incorporates all of the contents of the aforementioned Japanese patent applications by reference. [Background technology]

[0002] Semiconductor nanoparticles that are small enough to exhibit the quantum confinement effect have a band gap that depends on their particle size. Excitons formed within semiconductor nanoparticles by means of photoexcitation, charge injection, or other methods recombine to emit photons with an energy that corresponds to the band gap. Therefore, by appropriately selecting the composition and particle size of the semiconductor nanoparticles, it is possible to obtain light emission at a desired wavelength.

[0003] In the early stages of research into semiconductor nanoparticles, the focus was on elements containing Cd and Pb. However, because Cd and Pb are regulated substances under the Restrictions on the Use of Certain Hazardous Substances Act, research has been focused in recent years on non-Cd-based and non-Pb-based semiconductor nanoparticles.

[0004] Semiconductor nanoparticles have been used in a variety of applications, including displays, biolabeling, and solar cells. In particular, semiconductor nanoparticles have begun to be used in films as wavelength conversion layers for displays.

[0005] Figure 2 shows a schematic diagram of a device for converting wavelengths from a light source in a conventional display. As shown in Figure 2, a blue LED 101 is used as the light source, and the blue light is first converted to white light. A QD film 102, which is formed by dispersing semiconductor nanoparticles in a resin and forming it into a film with a thickness of approximately 100 μm, is preferably used to convert blue light to white light. The white light obtained by a wavelength conversion layer such as the QD film 102 is further converted into red light, green light, and blue light by color filter (R) 104, color filter (G) 105, and color filter (B) 106, respectively. Note that polarizing plates are omitted from Figure 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-162501 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, development has been progressing on a type of display (polarizer not shown) that uses QD patterning as a wavelength conversion layer without using a QD film, as shown in Figure 1. In the type of display shown in Figure 1, the blue light from the blue LED 1 light source is not converted to white light, but is instead directly converted to red light or green light using QD patterning (7, 8). The QD patterning (7, 8) is formed by patterning semiconductor nanoparticles dispersed in a resin, and its thickness is approximately 5 μm to 10 μm due to structural limitations of the display. For blue light, the blue light from the blue LED 1 light source is passed through a diffusion layer 9 containing a diffusing agent.

[0008] Furthermore, if the QD patterning (7, 8) does not absorb enough blue light and transmits it, color mixing occurs. The higher the mass fraction of semiconductor nanoparticles in the QD patterning (7, 8), the more the absorbance of the patterning can be improved, and color mixing can be prevented.

[0009] Patent Document 1 (JP 2002-162501 A) discloses a thin film molded product containing semiconductor nanoparticles at a high mass fraction. The thin film molded product described in Patent Document 1 does not necessarily require a polymer matrix component, so it is possible to form a thin film molded product containing semiconductor nanoparticles at a high mass fraction. However, when the thin film molded product described in Patent Document 1 is used as a wavelength conversion layer for a display or the like, it has been found to be insufficient in terms of strength, stability, and solvent resistance.

[0010] When a semiconductor nanoparticle composite is used in a wavelength conversion layer, the semiconductor nanoparticles and semiconductor nanoparticle composites may be exposed to high temperatures of about 200°C in the presence of oxygen during processes such as the process of forming the semiconductor nanoparticles into a film, the process of baking the semiconductor nanoparticle-containing photoresist, or the process of removing the solvent and curing the resin after inkjet patterning of the semiconductor nanoparticles. In such processes, ligands that have weak binding strength to the semiconductor nanoparticles are likely to detach from the surface of the semiconductor nanoparticles, resulting in a decrease in the fluorescence quantum efficiency of the semiconductor nanoparticle composite and the wavelength conversion layer itself.

[0011] Therefore, an object of the present invention is to provide a semiconductor nanoparticle composite that can be dispersed in a dispersion medium at a high concentration and has high fluorescence quantum efficiency. [Means for solving the problem]

[0012] The semiconductor nanoparticle composite according to the present invention is A semiconductor nanoparticle composite in which a ligand is coordinated to the surface of a semiconductor nanoparticle, the ligand comprises an organic group and a coordinating group; the organic group has one or more groups selected from an ether group, an ester group, and an amide group; The molecular weight of the ligand is 50 or more and 600 or less, the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.05 to 0.50; A semiconductor nanoparticle composite. In this application, the range indicated by "to" is a range that includes the numbers on both ends of the range. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a semiconductor nanoparticle composite that can be dispersed in a dispersion medium at a high concentration and has a high fluorescence quantum efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an outline of an example of a display using a semiconductor nanoparticle composite composition according to an embodiment of the present invention for QD patterning. [Figure 2] FIG. 1 is a diagram showing a schematic diagram of an example of a display using semiconductor nanoparticles as a QD film. DETAILED DESCRIPTION OF THE INVENTION

[0015] The semiconductor nanoparticle composite composition and semiconductor nanoparticle composite dispersion of the present invention are obtained by dispersing semiconductor nanoparticle composites in a dispersion medium. The semiconductor nanoparticle composite composition has a dispersion medium that is a monomer or prepolymer and further contains a crosslinking agent, and the mass fraction of semiconductor nanoparticles is 30 mass% or more. The diluted composition of the present invention is obtained by diluting the semiconductor nanoparticle composite composition of the present invention with an organic solvent. The semiconductor nanoparticle composite cured film and semiconductor nanoparticle composite patterned film of the present invention are obtained by curing or patterning the semiconductor nanoparticle composite composition or diluted composition of the present invention. The display element of the present invention comprises the semiconductor nanoparticle composite patterned film of the present invention.

[0016] (Semiconductor nanoparticle composite) The present invention relates to semiconductor nanoparticle composites comprising semiconductor nanoparticles and ligands coordinated to the semiconductor nanoparticles, as well as semiconductor nanoparticle composite compositions in which the semiconductor nanoparticle composites are dispersed. The semiconductor nanoparticle composites dispersed in the semiconductor nanoparticle composite compositions of the present invention have high luminescence properties, and the semiconductor nanoparticle composites can be contained at high mass fractions in semiconductor nanoparticle composite dispersions, semiconductor nanoparticle composite compositions, diluted compositions, semiconductor nanoparticle composite cured films, and semiconductor nanoparticle composite patterned films. Furthermore, the resulting semiconductor nanoparticle composite cured films and semiconductor nanoparticle composite patterned films have high fluorescence quantum efficiency.

[0017] In the present invention, the semiconductor nanoparticle composite refers to a semiconductor nanoparticle composite having light-emitting properties. The semiconductor nanoparticle composite contained in the semiconductor nanoparticle composite composition and semiconductor nanoparticle composite dispersion of the present invention is a particle that absorbs light of 340 nm to 480 nm and emits light with an emission peak wavelength of 400 nm to 750 nm.

[0018] The full width at half maximum (FWHM) of the emission spectrum of the semiconductor nanoparticle composite is preferably 38 nm or less, and more preferably 35 nm or less. When the full width at half maximum of the emission spectrum is in this range, color mixing can be reduced when the semiconductor nanoparticle composite is applied to displays and the like. The fluorescence quantum efficiency (QY) of the semiconductor nanoparticle composite is preferably 80% or more, and more preferably 85% or more. When the fluorescence quantum efficiency of the semiconductor nanoparticle composite is 80% or more, color conversion can be performed more efficiently. In the present invention, the fluorescence quantum efficiency of the semiconductor nanoparticle composite can be measured using a quantum efficiency measurement system.

[0019] -Semiconductor nanoparticles- The semiconductor nanoparticles constituting the semiconductor nanoparticle composite are not particularly limited as long as they satisfy the aforementioned luminescence characteristics, such as the fluorescence quantum efficiency and half-width. They may be particles made of a single semiconductor or particles made of two or more different semiconductors. In the case of particles made of two or more different semiconductors, the semiconductors may form a core-shell structure. For example, the particles may be core-shell particles having a core containing a group III element and a group V element and a shell containing group II and group VI elements that covers at least a portion of the core. The shell may have multiple shells of different compositions, or may have one or more gradient shells in which the ratio of the elements constituting the shell changes within the shell.

[0020] Specific examples of Group III elements include In, Al, and Ga. Specific examples of Group V elements include P, N and As. The composition of the core is not particularly limited, but InP is preferred from the standpoint of light emission characteristics.

[0021] The Group II elements are not particularly limited, but examples thereof include Zn and Mg. Examples of Group VI elements include S, Se, Te, and O. The composition of the shell is not particularly limited, but from the viewpoint of quantum confinement effect, ZnS, ZnSe, ZnSeS, ZnTeS, ZnTeSe, etc. are preferred. In particular, when Zn element is present on the surface of the semiconductor nanoparticles, the effects of the present invention can be more effectively exhibited.

[0022] When multiple shells are present, it is sufficient that at least one shell has the aforementioned composition. Furthermore, when a shell has a gradient type in which the ratio of elements constituting the shell changes within the shell, the shell does not necessarily have to have the composition indicated. In the present invention, whether the shell covers at least a portion of the core and the element distribution inside the shell can be confirmed, for example, by composition analysis using energy dispersive X-ray spectroscopy (TEM-EDX) with a transmission electron microscope.

[0023] The average particle size of the semiconductor nanoparticle composite is preferably 10 nm or less, and more preferably 7 nm or less. In the present invention, the average particle size of the semiconductor nanoparticle composite can be measured by calculating the particle sizes of 10 or more particles in an image of the particles observed using a transmission electron microscope (TEM) as the equivalent circle diameter (Heywood diameter). From the viewpoint of luminescence characteristics, a narrow particle size distribution is preferable, and the coefficient of variation of the particle size is preferably 15% or less. Here, the coefficient of variation is defined as "coefficient of variation = standard deviation of particle size / average particle size." A coefficient of variation of 15% or less is an indicator that a semiconductor nanoparticle composite with a narrower particle size distribution has been obtained.

[0024] An example of a method for producing semiconductor nanoparticles will be disclosed below. The core of the semiconductor nanoparticle can be formed by mixing a Group III precursor, a Group V precursor, and, if necessary, an additive in a solvent and heating the resulting precursor mixture. Solvents include, but are not limited to, 1-octadecene, hexadecane, squalane, oleylamine, trioctylphosphine, and trioctylphosphine oxide.

[0025] Group III precursors include, but are not limited to, acetates, carboxylates, and halides containing the group III elements. Group V precursors include, but are not limited to, organic compounds and gases containing the Group V elements. When the precursor is a gas, the core can be formed by injecting the gas into a precursor mixture containing other gases and allowing it to react.

[0026] The semiconductor nanoparticles may contain one or more elements other than Group III and Group V elements, as long as the effects of the present invention are not impaired. In this case, a precursor of the element may be added during core formation. Examples of additives include, but are not limited to, dispersants such as carboxylic acids, amines, thiols, phosphines, phosphine oxides, phosphinic acids, and phosphonic acids. The dispersant may also serve as a solvent. After the core of the semiconductor nanoparticle is formed, a halide can be added as needed to improve the light-emitting properties of the semiconductor nanoparticle.

[0027] In one embodiment, a metal precursor solution prepared by adding an In precursor and, if necessary, a dispersant to a solvent is mixed under vacuum, and the mixture is heated at 100°C to 300°C for 6 to 24 hours. After that, a P precursor is added, and the mixture is heated at 200°C to 400°C for 3 to 60 minutes, and then cooled. A halogen precursor is further added, and the mixture is heated at 25°C to 300°C, preferably 100°C to 300°C, and more preferably 150°C to 280°C, to obtain a core particle dispersion containing core particles.

[0028] By adding a shell-forming precursor to the core particle dispersion synthesized as described above, the semiconductor nanoparticles can adopt a core-shell structure, thereby increasing the fluorescence quantum efficiency (QY) and stability. The elements that make up the shell are thought to have an alloy, heterostructure, or amorphous structure on the surface of the core particle, but it is also possible that some of them migrate to the inside of the core particle by diffusion.

[0029] The added shell-forming element is present mainly near the surface of the core particle and plays a role in protecting the semiconductor nanoparticles from external factors. In the core-shell structure of the semiconductor nanoparticles, the shell preferably covers at least a part of the core, and more preferably uniformly covers the entire surface of the core particle.

[0030] In one embodiment, a Zn precursor and a Se precursor are added to the aforementioned core particle dispersion, followed by heating at 150° C. to 300° C., preferably 180° C. to 250° C., and then a Zn precursor and a S precursor are added, followed by heating at 200° C. to 400° C., preferably 250° C. to 350° C. This allows core-shell type semiconductor nanoparticles to be obtained. Here, although not particularly limited, examples of Zn precursors that can be used include carboxylates such as zinc acetate, zinc propionate, and zinc myristate, halides such as zinc chloride and zinc bromide, and organic salts such as diethylzinc. As the Se precursor, phosphine selenides such as tributylphosphine selenide, trioctylphosphine selenide, and tris(trimethylsilyl)phosphine selenide, selenols such as benzeneselenol and selenocysteine, and selenium / octadecene solution can be used. As the S precursor, phosphine sulfides such as tributylphosphine sulfide, trioctylphosphine sulfide, and tris(trimethylsilyl)phosphine sulfide, thiols such as octanethiol, dodecanethiol, and octadecanethiol, and sulfur / octadecene solution can be used. The shell precursors may be mixed in advance and added all at once or in multiple portions, or each may be added separately all at once or in multiple portions. When the shell precursors are added in multiple portions, heating may be performed at different temperatures after each addition of the shell precursors.

[0031] In the present invention, the method for producing semiconductor nanoparticles is not particularly limited, and in addition to the methods described above, any other conventional production method such as the hot injection method, the homogeneous solvent method, the reverse micelle method, or the CVD method may be employed.

[0032] -Ligand- In the present invention, the semiconductor nanoparticle composite has a ligand coordinated to the surface of the semiconductor nanoparticle. The term "coordination" used here means that the ligand chemically influences the surface of the semiconductor nanoparticle. The ligand may be bonded to the surface of the semiconductor nanoparticle by a coordinate bond or any other bonding mode (e.g., covalent bond, ionic bond, hydrogen bond, etc.), or, if at least a portion of the surface of the semiconductor nanoparticle has a ligand, the ligand may not necessarily form a bond.

[0033] The semiconductor nanoparticle composite composition, the semiconductor nanoparticle composite cured film, and the semiconductor nanoparticle composite that can be contained at a high mass fraction during patterning preferably satisfy the following requirements. The mass ratio of the ligand to the semiconductor nanoparticles, where the semiconductor nanoparticles are taken as 1, is preferably 0.05 to 0.50, and more preferably 0.10 to 0.40. By keeping the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) at 0.50 or less, the size and volume of the semiconductor nanoparticle composites are prevented from increasing, and the semiconductor nanoparticle composite composition and the semiconductor nanoparticle composite cured film can contain the ligand at a high mass fraction. Furthermore, by keeping the mass ratio (ligand / semiconductor nanoparticles) at 0.05 or more, the semiconductor nanoparticles can be sufficiently covered with the ligand, preventing a decrease in the luminescence properties of the semiconductor nanoparticles and a decrease in their dispersibility in the cured film or dispersion medium. The fluorescence quantum efficiency of the semiconductor nanoparticle composite composition and the semiconductor nanoparticle composite cured film is preferably 60% or higher, and more preferably 70% or higher.

[0034] The ligand is an organic ligand containing an organic group, and preferably comprises a coordinating group that coordinates with the semiconductor nanoparticle and an organic group. The organic group is preferably a monovalent hydrocarbon group that may have a substituent or a heteroatom, and more preferably an organic group in which a substituent containing a heteroatom is bonded to a vinyl group. This structure allows the semiconductor nanoparticle composite to be dispersed at a high mass fraction in the cured film described below while maintaining a high quantum yield. The organic group is not particularly limited, but examples include alkyl groups, alkenyl groups, alkynyl groups, vinylene groups, vinylidene groups, ether groups, ester groups, carbonyl groups, amide groups, sulfide groups, and organic groups formed by combining these groups. Furthermore, the organic group may contain, as a substituent, a phenyl group, a hydroxyl group, an alkoxy group, an amino group, a carboxyl group, a mercapto group, a chloro group, a bromo group, a vinyl group, an acrylic group, a methacrylic group, or the like. The organic group preferably has one or more groups selected from an ether group, an ester group, and an amide group. This structure allows the semiconductor nanoparticle composite to be dispersed in an organic dispersion medium having an SP value (solubility parameter) of 8.5 to 15.0. Furthermore, it is more preferable that the organic group has a vinyl group and / or a vinylene group. This structure allows the semiconductor nanoparticle composite and the curable composition to be chemically bonded, improving the strength of the film and the stability of the semiconductor nanoparticles in the film. Substituents containing a vinyl group are not particularly limited, but examples include an acrylic group and a methacrylic group.

[0035] The coordinating group is preferably a mercapto group or a carboxyl group, with a mercapto group being particularly preferred, due to the strength of coordination to the semiconductor nanoparticles. One or more mercapto groups are preferred. Coordination of the coordinating group of the ligand to the surface of the semiconductor nanoparticles can prevent a decrease in the fluorescence quantum efficiency of the semiconductor nanoparticles. Furthermore, when used in a wavelength conversion layer, semiconductor nanoparticle composites having the ligand can prevent a decrease in the fluorescence quantum efficiency of the wavelength conversion layer, even when exposed to high processing temperatures, because the ligand is strongly coordinated to the semiconductor nanoparticles. It is also possible to use multiple types of ligands in combination.

[0036] In a first embodiment of the semiconductor nanoparticle composite, the molecular weight of the ligand is preferably 50 to 600, more preferably 50 to 450. When multiple types of ligands are used in combination, the molecular weight of each of the ligands is preferably 50 to 600, more preferably 50 to 450. By using a ligand with a molecular weight of 600 or less, it is possible to prevent the size and volume of the semiconductor nanoparticle composite from increasing, and to easily increase the mass fraction of the semiconductor nanoparticles in the cured film. On the other hand, by using a ligand with a molecular weight of 50 or more, it is possible to sufficiently cover the surface of the semiconductor nanoparticles with the ligand, which prevents a decrease in the luminescence properties of the semiconductor nanoparticle composite and also improves dispersibility in the cured film and dispersion medium.

[0037] In another embodiment of the semiconductor nanoparticle composite, the ligand preferably has two or more coordinating groups per molecule. When the ligand has two or more coordinating groups per molecule, one ligand molecule can coordinate to multiple locations on the surface of the semiconductor nanoparticle, which can suppress increases in size and volume of the semiconductor nanoparticle composite and improve dispersibility in a dispersion medium or a cured film. The coordinating group of the ligand is preferably a mercapto group. The mercapto group of the ligand coordinates strongly to the shell of the semiconductor nanoparticle, filling in defects in the semiconductor nanoparticle and contributing to preventing a decrease in the luminescence properties of the semiconductor nanoparticle composite. In particular, when Zn is present on the surface of the semiconductor nanoparticle, the strength of the bond between the mercapto group and Zn enhances the aforementioned effect.

[0038] (Method of manufacturing semiconductor nanoparticle composite) An example of a method for producing a semiconductor nanoparticle composite will be disclosed below. There are no limitations on the method for coordinating the ligand to the semiconductor nanoparticles, but a ligand exchange method utilizing the coordination power of the ligand can be used. Specifically, semiconductor nanoparticles in which the organic compound used in the process of producing the semiconductor nanoparticles described above is coordinated to the surface of the semiconductor nanoparticles are contacted with the target ligand in the liquid phase, thereby obtaining a semiconductor nanoparticle composite in which the target ligand is coordinated to the surface of the semiconductor nanoparticles. In this case, a liquid phase reaction using a solvent as described below is usually performed, but if the ligand used is liquid under the reaction conditions, it is also possible to use the ligand itself as the solvent and adopt a reaction format in which no other solvent is added.

[0039] Furthermore, if a purification step and a redispersion step as described below are carried out before the ligand exchange, the ligand exchange can be easily carried out. In one embodiment, the semiconductor nanoparticle-containing dispersion liquid after the production of semiconductor nanoparticles is purified and redispersed, and then a solvent containing the target ligand is added and stirred at 50°C to 200°C for 1 minute to 120 minutes under a nitrogen atmosphere to obtain the desired semiconductor nanoparticle composite.

[0040] Semiconductor nanoparticles and semiconductor nanoparticle composites can be purified as follows. In one embodiment, the semiconductor nanoparticle composites can be precipitated from the dispersion by adding a polarity-reversing solvent such as acetone. The precipitated semiconductor nanoparticle composites can be recovered by filtration or centrifugation, while the supernatant containing unreacted starting materials and other impurities can be discarded or recycled. The precipitated semiconductor nanoparticle composites can then be washed with additional dispersant and redispersed. This purification process can be repeated, for example, 2 to 4 times, or until the desired purity is reached. In the present invention, the method for purifying the semiconductor nanoparticle composite is not particularly limited, and in addition to the methods described above, any method such as coagulation, liquid-liquid extraction, distillation, electrodeposition, size exclusion chromatography and / or ultrafiltration, can be used alone or in combination.

[0041] The optical properties of semiconductor nanoparticles can be measured using a quantum efficiency measurement system (e.g., QE-2100, manufactured by Otsuka Electronics). The obtained semiconductor nanoparticles are dispersed in a dispersion medium, and an emission spectrum is obtained by irradiating them with excitation light. The fluorescence quantum efficiency (QY) and full width at half maximum (FWHM) are calculated from the emission spectrum after reexcitation correction, which is obtained by subtracting the reexcitation fluorescence emission spectrum from the obtained emission spectrum. Examples of dispersion media used for measurement include normal hexane, toluene, acetone, PGMEA, and octadecene.

[0042] In the present invention, the state in which the semiconductor nanoparticle composite is dispersed in a dispersion medium refers to a state in which, when the semiconductor nanoparticle composite and the dispersion medium are mixed, the semiconductor nanoparticle composite does not precipitate or does not remain as visible turbidity (cloudiness). Note that the semiconductor nanoparticle composite dispersed in the dispersion medium is referred to as a dispersion liquid.

[0043] The semiconductor nanoparticle composite composition and the semiconductor nanoparticle composite dispersion of the present invention have the above-described configuration, and are dispersed in a dispersion medium having an SP value (solubility parameter) of 8.5 to 15.0 to form a semiconductor nanoparticle composite dispersion. Examples of the dispersion medium are not particularly limited, but include alcohols such as methanol, ethanol, isopropyl alcohol, and normal propyl alcohol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, normal butyl acetate, and ethyl lactate; ethers such as diethyl ether, dipropyl ether, dibutyl ether, and tetrahydrofuran; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, and the like. Examples of suitable dispersion media include glycol ethers such as propylene glycol monoethyl ether (PGME), propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene glycol diethyl ether, and dipropylene glycol diethyl ether, and glycol ether esters such as ethylene glycol acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), and dipropylene glycol monoethyl ether acetate. The semiconductor nanoparticle composite can be dispersed in one or more dispersion media selected from the above-mentioned dispersion media. Furthermore, as described in the examples above, polar dispersion media such as alcohols, ketones, esters, glycol ethers, and glycol ether esters can also be selected. By dispersing the semiconductor nanoparticle composite in these dispersion media, the semiconductor nanoparticle composite can be used while maintaining its dispersibility when applied to cured films or resins, as described below. Among these, glycol ethers or glycol ether esters are preferred from the viewpoints of solubility in a wide range of resins and uniformity of the coating film when applied. In particular, PGMEA and PGME are commonly used as dilution solvents in the photoresist field, and if semiconductor nanoparticles can be dispersed in PGMEA and PGME, the semiconductor nanoparticles can be widely applied in the photoresist field. The SP value here is the Hildebrand solubility parameter, which is a value calculated from the Hansen solubility parameter, which can be determined using values ​​in handbooks, such as "Hansen Solubility Parameters: A User's Handbook", 2nd Edition, C. M. Hansen (2007), or the Practice (HSPiP) program (2nd Edition) provided by Hanson and Abbot et al.

[0044] When the concentration of the inorganic component of the semiconductor nanoparticle composite in the semiconductor nanoparticle composite dispersion is 1 mg / mL, i.e., when the content of the inorganic component of the semiconductor nanoparticle composite per mL of dispersion medium of the semiconductor nanoparticle composite dispersion is 1 mg, the absorbance of the semiconductor nanoparticle composite dispersion should be 0.6 or more at an optical path length of 1 cm for light with a wavelength of 450 nm, and is more preferably 0.7 or more. When the absorbance of the dispersion is 0.6 or more at an optical path length of 1 cm, it becomes possible to absorb more light with a smaller amount of liquid when applied to devices, etc. The semiconductor nanoparticle composite described above is suitable as the semiconductor nanoparticle composite contained in the semiconductor nanoparticle composite composition, diluted composition, semiconductor nanoparticle composite cured film, semiconductor nanoparticle composite patterned film, display element, and semiconductor nanoparticle composite dispersion of the present invention.

[0045] (Semiconductor nanoparticle composite composition) In the present invention, a monomer or a prepolymer can be selected as the dispersion medium for the semiconductor nanoparticle composite dispersion. Furthermore, by adding a crosslinking agent, the semiconductor nanoparticle composite contained in the semiconductor nanoparticle composite composition of the present invention can form a semiconductor nanoparticle composite composition with the monomer or prepolymer and the crosslinking agent. The monomer is not particularly limited, but is preferably a (meth)acrylic monomer, which allows for a wide range of applications for semiconductor nanoparticles. Depending on the application of the semiconductor nanoparticle composite dispersion, the (meth)acrylic monomer may be isobornyl acrylate (IBOA), methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, isodecyl (meth)acrylate, or lauryl (meth)acrylate. , stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 3,5,5-trimethylcyclohexanol (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, methoxytriethylene glycol acrylate, 2-ethylhexyl diglycol acrylate, methoxypolyethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl (meth)acrylate, 2-phenoxydiethylene glycol (meth)acrylate, 2-phenoxypolyethylene glycol (meth)acrylate (n≒2), tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, dicyclopentanyl Oxylethyl (meth)acrylate, isobornyloxylethyl (meth)acrylate, adamantyl (meth)acrylate, dimethyl adamantyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, benzyl (meth)acrylate, ω-carboxy-polycaprolactone (n≒2) monoacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-phenoxyethyl (meth)acrylate, (2-methyl-2-ethyl-1,The (meth)acrylic monomers may be selected from (meth)acrylic monomers such as (3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, o-phenylphenolethoxy (meth)acrylate, dimethylamino (meth)acrylate, diethylamino (meth)acrylate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, glycidyl (meth)acrylate, 2-(meth)acryloyloxyethyl phosphate, acryloylmorpholine, dimethylacrylamide, dimethylaminopropyl acrylamide, isopropyl acrylamide, diethyl acrylamide, hydroxyethyl acrylamide, and N-acryloyloxyethyl hexahydrophthalimide. These may be used alone or in combination of two or more. The prepolymer is not particularly limited, but examples thereof include (meth)acrylic resin prepolymers, silicone resin prepolymers, epoxy resin prepolymers, maleic acid resin prepolymers, butyral resin prepolymers, polyester resin prepolymers, melamine resin prepolymers, phenolic resin prepolymers, and polyurethane resin prepolymers. The crosslinking agent is selected from polyfunctional (meth)acrylates, polyfunctional silane compounds, polyfunctional amines, polyfunctional carboxylic acids, polyfunctional thiols, polyfunctional alcohols, polyfunctional isocyanates, and the like, depending on the type of monomer in the semiconductor nanoparticle composite composition. Furthermore, the semiconductor nanoparticle composite composition may further contain various organic solvents that do not affect curing, such as aliphatic hydrocarbons such as pentane, hexane, cyclohexane, isohexane, heptane, octane, and petroleum ether, alcohols, ketones, esters, glycol ethers, glycol ether esters, aromatic hydrocarbons such as benzene, toluene, xylene, and mineral spirits, and alkyl halides such as dichloromethane and chloroform. When the semiconductor nanoparticle composite composition contains an organic solvent, the content of the organic solvent should be such that the mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite composition is 30% or more.

[0046] Furthermore, the semiconductor nanoparticle composite composition may contain appropriate initiators, scattering agents, catalysts, binders, surfactants, adhesion promoters, antioxidants, ultraviolet absorbers, anti-aggregation agents, dispersants, and the like, depending on the type of monomer in the semiconductor nanoparticle composite composition. Furthermore, to improve the optical properties of the semiconductor nanoparticle composite composition or the semiconductor nanoparticle composite cured film described below, the semiconductor nanoparticle composite composition may contain a scattering agent. The scattering agent is a metal oxide such as titanium oxide or zinc oxide, and the particle size thereof is preferably 100 nm to 500 nm. From the viewpoint of scattering effect, the particle size of the scattering agent is more preferably 200 nm to 400 nm. The inclusion of a scattering agent improves the absorbance by about two times. The content of the scattering agent is preferably 2% by mass to 30% by mass of the composition, and more preferably 5% by mass to 20% by mass from the viewpoint of maintaining the patternability of the composition.

[0047] The configuration of the semiconductor nanoparticle composite of the present invention allows the mass fraction of semiconductor nanoparticles in the semiconductor nanoparticle composite composition to be 30 mass% or more. By setting the mass fraction of semiconductor nanoparticles in the semiconductor nanoparticle composite composition to 30 mass% to 95 mass%, the semiconductor nanoparticle composites and semiconductor nanoparticles can be dispersed at a high mass fraction even in the cured film described below.

[0048] When the semiconductor nanoparticle composite composition of the present invention is formed into a 10 μm film, the absorbance of light with a wavelength of 450 nm from the normal direction of the film is preferably 1.0 or more, more preferably 1.3 or more, and even more preferably 1.5 or more. This allows for efficient absorption of backlight light, thereby enabling the thickness of the cured film described below to be reduced, and the device to which it is applied to be made smaller.

[0049] (Diluted Composition) The diluted composition of the present invention is obtained by diluting the aforementioned semiconductor nanoparticle composite composition of the present invention with an organic solvent. The organic solvent used to dilute the semiconductor nanoparticle composite composition is not particularly limited, and examples include aliphatic hydrocarbons such as pentane, hexane, cyclohexane, isohexane, heptane, octane, and petroleum ether, alcohols, ketones, esters, glycol ethers, glycol ether esters, aromatic hydrocarbons such as benzene, toluene, xylene, and mineral spirits, and alkyl halides such as dichloromethane and chloroform. Among these, glycol ethers and glycol ether esters are preferred from the viewpoints of solubility in a wide range of resins and film uniformity upon application. When the organic solvent contained in the diluted composition of the present invention is removed by drying or the like, a semiconductor nanoparticle composite composition having a mass fraction of semiconductor nanoparticles of 30% or more is obtained.

[0050] (Semiconductor nanoparticle composite cured film) In the present invention, the term "semiconductor nanoparticle composite cured film" refers to a film containing a semiconductor nanoparticle composite and that has been cured. The semiconductor nanoparticle composite cured film can be obtained by curing the semiconductor nanoparticle composite composition or diluted composition described above into a film. The semiconductor nanoparticle composite cured film contains semiconductor nanoparticles, ligands coordinated to the surfaces of the semiconductor nanoparticles, a polymer matrix, and a crosslinking agent. The polymer matrix is ​​not particularly limited, and examples thereof include (meth)acrylic resin, silicone resin, epoxy resin, maleic acid resin, butyral resin, polyester resin, melamine resin, phenolic resin, polyurethane resin, etc. Note that a semiconductor nanoparticle composite cured film may be obtained by curing the aforementioned semiconductor nanoparticle composite composition.

[0051] The method for curing the film is not particularly limited, but the film can be cured by a curing method suitable for the composition that constitutes the film, such as heat treatment or ultraviolet treatment. The semiconductor nanoparticles and the ligands coordinated to the surfaces of the semiconductor nanoparticles contained in the semiconductor nanoparticle composite cured film preferably constitute the semiconductor nanoparticle composite described above. By configuring the semiconductor nanoparticle composite contained in the semiconductor nanoparticle composite cured film of the present invention as described above, it is possible to disperse the semiconductor nanoparticle composite in the cured film at a higher mass fraction. The mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite cured film should be 30 mass% or more, and more preferably 40 mass% or more. However, if it is 70 mass% or more, the composition that constitutes the film will be reduced, making it difficult to cure and form the film. By incorporating the semiconductor nanoparticle composite described above into the semiconductor nanoparticle composite cured film of the present invention, the semiconductor nanoparticle composite cured film of the present invention has a very high absorbance of light with a wavelength of 450 nm. Therefore, even if the mass fraction of semiconductor nanoparticles in the semiconductor nanoparticle composite cured film is less than 70 mass%, or even less than 60 mass%, the semiconductor nanoparticle composite cured film of the present invention can have a sufficient absorbance value, as described below.

[0052] The semiconductor nanoparticle composite cured film of the present invention contains a high mass fraction of semiconductor nanoparticle composites having high absorbance, and therefore the absorbance of the semiconductor nanoparticle composite cured film can be increased. When the semiconductor nanoparticle composite cured film is 10 μm thick, the absorbance of light with a wavelength of 450 nm from the normal direction of the semiconductor nanoparticle composite cured film is preferably 1.0 or more, more preferably 1.3 or more, and even more preferably 1.5 or more.

[0053] Furthermore, since the semiconductor nanoparticle composite cured film of the present invention contains a semiconductor nanoparticle composite with high luminescence properties, it is possible to provide a semiconductor nanoparticle composite cured film with high luminescence properties. The fluorescence quantum efficiency of the semiconductor nanoparticle composite cured film is preferably 70% or more, and more preferably 80% or more.

[0054] In order to miniaturize devices to which the semiconductor nanoparticle composite cured film is applied, the thickness of the semiconductor nanoparticle composite cured film is preferably 50 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less.

[0055] (Semiconductor nanoparticle composite patterned film and display element) The semiconductor nanoparticle composite patterned film of the present invention can be obtained by patterning the semiconductor nanoparticle composite composition or diluted composition into a film. The method for patterning the semiconductor nanoparticle composite composition or diluted composition is not particularly limited, and examples thereof include spin coating, bar coating, inkjet printing, screen printing, and photolithography. The display element of the present invention uses the semiconductor nanoparticle composite patterned film of the present invention. For example, by using the semiconductor nanoparticle composite patterned film as a wavelength conversion layer, a display element having excellent fluorescence quantum efficiency can be provided.

[0056] The semiconductor nanoparticle composite composition of the present invention employs the following configuration. (1) A semiconductor nanoparticle composite composition in which a semiconductor nanoparticle composite is dispersed in a dispersion medium, The semiconductor nanoparticle composite has semiconductor nanoparticles and ligands coordinated to the surfaces of the semiconductor nanoparticles, the ligand comprises an organic group; the dispersion medium is a monomer or a prepolymer; the semiconductor nanoparticle composite composition further comprises a crosslinker; The mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite composition is 30 mass% or more. Semiconductor nanoparticle composite compositions. (2) The mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite composition is 40 mass% or more. The semiconductor nanoparticle composite composition according to (1) above. (3) When the semiconductor nanoparticle composite composition is formed into a 10 μm film, the absorbance of the film for light with a wavelength of 450 nm from the normal direction is 1.0 or more. The semiconductor nanoparticle composite composition according to (1) or (2) above. (4) the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.05 to 0.50; The semiconductor nanoparticle composite composition according to any one of (1) to (3) above. (5) The mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.10 to 0.40. The semiconductor nanoparticle composite composition according to any one of (1) to (4) above. (6) The ligand contains a hydrocarbon group which may have a substituent or a heteroatom, and a coordinating group. The semiconductor nanoparticle composite composition according to any one of (1) to (5) above. (7) The ligand has one or more groups selected from an ether group, an ester group, and an amide group. The semiconductor nanoparticle composite composition according to any one of (1) to (6) above. (8) the ligand further comprises a coordinating group; The organic group has a vinyl group and / or a vinylidene group. The semiconductor nanoparticle composite composition according to any one of (1) to (7) above. (9) The semiconductor nanoparticles have an average particle size of 10 nm or less. The semiconductor nanoparticle composite composition according to any one of (1) to (8) above. (10) The semiconductor nanoparticles have an average particle size of 7 nm or less. The semiconductor nanoparticle composite composition according to any one of (1) to (9) above. (11) The semiconductor nanoparticle composite composition has a fluorescence quantum efficiency of 60% or more. The semiconductor nanoparticle composite composition according to any one of (1) to (10) above. (12) The semiconductor nanoparticle composite composition has a fluorescence quantum efficiency of 70% or more. The semiconductor nanoparticle composite composition according to any one of (1) to (11) above. (13) The molecular weight of the ligand is 50 or more and 600 or less. The semiconductor nanoparticle composite composition according to any one of (1) to (12) above. (14) The molecular weight of the ligand is 50 or more and 450 or less. The semiconductor nanoparticle composite composition according to any one of (1) to (13) above. (15) The ligand has one or more mercapto groups. The semiconductor nanoparticle composite composition according to any one of (1) to (14) above. (16) The ligand has two or more mercapto groups. The semiconductor nanoparticle composite composition according to any one of (1) to (15) above. (17) The ligand is of two or more types. The semiconductor nanoparticle composite composition according to any one of (1) to (16) above. (18) The semiconductor nanoparticles contain In and P. The semiconductor nanoparticle composite composition according to any one of (1) to (17) above. (19) The semiconductor nanoparticles contain Zn on the surface thereof. The semiconductor nanoparticle composite composition according to any one of (1) to (18) above. (20) The semiconductor nanoparticle composite has a fluorescence quantum efficiency of 80% or more. The semiconductor nanoparticle composite composition according to any one of (1) to (19) above. (21) The semiconductor nanoparticle composite has an emission spectrum having a half-width of 38 nm or less. The semiconductor nanoparticle composite composition according to any one of (1) to (20) above.

[0057] The diluted composition of the present invention has the following constitution. (22) A diluted composition obtained by diluting the semiconductor nanoparticle composite composition according to any one of (1) to (21) above with an organic solvent. (23) The diluted composition according to (22) above, wherein the organic solvent is a glycol ether and / or a glycol ether ester.

[0058] The semiconductor nanoparticle composite cured film of the present invention employs the following configuration. (24) A semiconductor nanoparticle composite cured film obtained by curing the semiconductor nanoparticle composite composition according to any one of (1) to (21) above, or the diluted composition according to (22) or (23) above.

[0059] The semiconductor nanoparticle composite patterned film of the present invention employs the following configuration. (25) A semiconductor nanoparticle composite patterned film obtained by patterning the semiconductor nanoparticle composite composition according to any one of (1) to (21) above, or the diluted composition according to (22) or (23) above.

[0060] The display element of the present invention employs the following configuration. (26) A display device comprising the semiconductor nanoparticle composite patterned film according to (25) above.

[0061] The semiconductor nanoparticle composite dispersion of the present invention employs the following configuration. <1> A dispersion in which semiconductor nanoparticle composites in which ligands are coordinated to the surfaces of semiconductor nanoparticles are dispersed in a dispersion medium, When the concentration of the inorganic component of the semiconductor nanoparticle composite in the dispersion is 1 mg / mL, the absorbance at a path length of 1 cm for light with a wavelength of 450 nm is 0.6 or more, the ligand comprises an organic group; Semiconductor nanoparticle composite dispersion. <2> The SP value of the dispersion medium is 8.5 or more. the above <1> The semiconductor nanoparticle composite dispersion liquid according to claim 1. <3> The SP value of the dispersion medium is 9.0 or more. the above <1> or <2> The semiconductor nanoparticle composite dispersion liquid according to claim 1. <4> The dispersion medium is one or a mixed dispersion medium of two or more selected from glycol ethers and glycol ether esters. the above <1> ~ <3> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <5> The dispersion medium is PGMEA or PGME; the above <1> ~ <4> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <6> the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.05 to 0.50; the above <1> ~ <5> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <7> the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.10 to 0.40; the above <1> ~ <6> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <8> The semiconductor nanoparticles have an average particle size of 10 nm or less. the above <1> ~ <7> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <9> The semiconductor nanoparticles have an average particle size of 7 nm or less. the above <1> ~ <8> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <10> The ligand contains a hydrocarbon group which may have a substituent or a heteroatom, and a coordinating group. the above <1> ~ <9> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <11> The molecular weight of the ligand is 50 or more and 600 or less. the above <1> ~ <10> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <12> The molecular weight of the ligand is 50 or more and 450 or less. the above <1> ~ <11> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <13> The ligand has at least one mercapto group. the above <1> ~ <12> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <14> the ligand further comprises a coordinating group; The organic group has one or more groups selected from an ether group, an ester group, and an amide group. the above <1> ~ <13> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <15> the ligand further comprises a coordinating group; The organic group has a vinyl group and / or a vinylidene group. the above <1> ~ <14> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <16> The ligand has two or more mercapto groups. the above <1> ~ <15> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <17> The ligand is of two or more types. the above <1> ~ <16> The nanoparticle composite dispersion liquid according to any one of the preceding claims. <18> containing Zn on the surface of the semiconductor nanoparticles, the above <1> ~ <17> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <19> The semiconductor nanoparticles comprise In and P. the above <1> ~ <18> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <20> The semiconductor nanoparticle composite has a fluorescence quantum efficiency of 80% or more. the above <1> ~ <19> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims. <21> The semiconductor nanoparticle composite has an emission spectrum with a half-width of 38 nm or less. the above <1> ~ <20> The semiconductor nanoparticle composite dispersion liquid according to any one of the preceding claims.

[0062] The semiconductor nanoparticle composite cured film of the present invention employs the following configuration. [1] A semiconductor nanoparticle composite cured film in which a semiconductor nanoparticle composite is dispersed in a polymer matrix, The semiconductor nanoparticle composite has semiconductor nanoparticles and ligands coordinated to the surfaces of the semiconductor nanoparticles, the ligand comprises an organic group; the polymer matrix is ​​crosslinked with a crosslinking agent; the mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite cured film is 30 mass% or more; Semiconductor nanoparticle composite cured film. [2] The semiconductor nanoparticle composite cured film further contains a scattering agent. The semiconductor nanoparticle composite cured film according to [1] above. [3] The mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite cured film is 40 mass% or more. The semiconductor nanoparticle composite cured film according to the above [1] or [2]. [4] When the thickness of the semiconductor nanoparticle composite cured film is 10 μm, the absorbance of the semiconductor nanoparticle composite cured film for light with a wavelength of 450 nm from the normal direction of the film is 1.0 or more. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [3]. [5] When the thickness of the semiconductor nanoparticle composite cured film is 10 μm, the absorbance of the semiconductor nanoparticle composite cured film for light with a wavelength of 450 nm from the normal direction of the film is 1.5 or more. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [4]. [6] The scattering agent is a metal oxide. The semiconductor nanoparticle composite cured film according to any one of the above [2] to [5]. [7] The mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.05 to 0.50. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [6]. [8] The mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.10 to 0.40. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [7]. [9] The ligand includes an organic group which is a hydrocarbon group which may have a substituent or a heteroatom, and a coordinating group. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [8].

[10] The ligand has one or more groups selected from an ether group, an ester group, and an amide group. The semiconductor nanoparticle composite cured film according to any one of the above [1] to [9].

[11] The ligand further comprises a coordinating group; The organic group has a vinyl group and / or a vinylidene group. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[10] .

[12] The semiconductor nanoparticles have an average particle size of 10 nm or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[11] .

[13] The semiconductor nanoparticles have an average particle size of 7 nm or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[12] .

[14] The fluorescence quantum efficiency of the semiconductor nanoparticle composite cured film is 70% or more. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[13] .

[15] The molecular weight of the ligand is 50 or more and 600 or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[14] .

[16] The molecular weight of the ligand is 50 or more and 450 or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[15] .

[17] The ligand has one or more mercapto groups. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[16] .

[18] The ligand has two or more mercapto groups. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[17] .

[19] The ligand is of two or more types. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[18] .

[20] The semiconductor nanoparticles contain In and P. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[19] .

[21] The semiconductor nanoparticles contain Zn on their surfaces. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[20] .

[22] The semiconductor nanoparticle composite has a fluorescence quantum efficiency of 80% or more. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[21] .

[23] The semiconductor nanoparticle composite has an emission spectrum with a half-width of 38 nm or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[22] .

[24] The thickness of the semiconductor nanoparticle composite cured film is 50 μm or less. The semiconductor nanoparticle composite cured film according to any one of the above [1] to

[23] .

[0063] The semiconductor nanoparticle composite of the present invention employs the following configuration. <1> A semiconductor nanoparticle composite in which a ligand is coordinated to the surface of a semiconductor nanoparticle, the ligand comprises an organic group; the mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) is 0.05 to 0.50; Semiconductor nanoparticle composites. <2> The mass ratio of the ligand to the semiconductor nanoparticles is 0.10 to 0.40. The semiconductor nanoparticle composite according to <1> above. <3> The semiconductor nanoparticles contain Zn on the surface thereof. The semiconductor nanoparticle composite according to <1> or <2> above. <4> The semiconductor nanoparticles contain In and P, The semiconductor nanoparticle composite according to any one of the above items <1> to <3>. <5> The semiconductor nanoparticles have an average particle size of 10 nm or less. The semiconductor nanoparticle composite according to any one of the above items <1> to <4>. <6> The semiconductor nanoparticles have an average particle size of 7 nm or less. The semiconductor nanoparticle composite according to any one of the above items <1> to <5>. <7> The semiconductor nanoparticle composite has a fluorescence quantum efficiency of 80% or more. The semiconductor nanoparticle composite according to any one of the above items <1> to <6>. <8> The semiconductor nanoparticle composite has an emission spectrum with a half-width of 38 nm or less. The semiconductor nanoparticle composite according to any one of the above items <1> to <7>. <9> The ligand contains a monovalent hydrocarbon group which may have a substituent or a heteroatom. The semiconductor nanoparticle composite according to any one of the above items <1> to <8>. <10> The molecular weight of the ligand is 50 or more and 600 or less. The semiconductor nanoparticle composite according to any one of the above items <1> to <9>. <11> The molecular weight of the ligand is 50 or more and 450 or less. The semiconductor nanoparticle composite according to any one of the above items <1> to <10>. <12> The ligand contains at least one mercapto group. The semiconductor nanoparticle composite according to any one of the above items <1> to <11>. <13> The ligand further contains a coordinating group, The organic group has one or more groups selected from an ether group, an ester group, and an amide group. The semiconductor nanoparticle composite according to any one of the above items <1> to <12>. <14> The ligand further comprises a coordinating group, The organic group has a vinyl group and / or a vinylidene group. The semiconductor nanoparticle composite according to any one of the above items <1> to <13>. <15> The ligand has two or more mercapto groups. The semiconductor nanoparticle composite according to any one of the above items <1> to <14>. <16> The ligand is of two or more types. The semiconductor nanoparticle composite according to any one of the above items <1> to <15>.

[0064] It will be understood that the structures and / or methods described herein are presented by way of example and that numerous variations are possible, and therefore, these specific examples or examples should not be construed in a limiting sense. A particular procedure or method described herein may represent one of numerous processing methods. Thus, various acts illustrated and / or described may be performed in the order illustrated and / or described, or may be omitted. Similarly, the order of the methods described above may be changed. The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various methods, systems, and structures, as well as other features, functions, acts, and / or properties disclosed herein, and all equivalents thereof. [Example]

[0065] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0066] [Example 1] (Synthesis of semiconductor nanoparticles) The semiconductor nanoparticles were synthesized according to the following method. -Preparation of precursor- --Preparation of Zn precursor solution-- 40 mmol of zinc oleate and 75 mL of octadecene were mixed and heated at 110°C for 1 hour under vacuum to prepare a Zn precursor with [Zn] = 0.4M. --Preparation of Se precursor (trioctylphosphine selenide)-- 22 mmol of selenium powder and 10 mL of trioctylphosphine were mixed in a nitrogen atmosphere and stirred until completely dissolved to obtain trioctylphosphine selenide with [Se] = 2.2 M. --Preparation of S precursor (trioctylphosphine sulfide)-- 22 mmol of sulfur powder and 10 mL of trioctylphosphine were mixed in a nitrogen atmosphere and stirred until completely dissolved to obtain trioctylphosphine sulfide with [S] = 2.2 M. -Core formation- Indium acetate (0.3 mmol) and zinc oleate (0.6 mmol) were added to a mixture of oleic acid (0.9 mmol), 1-dodecanethiol (0.1 mmol), and octadecene (10 mL), and the mixture was heated to approximately 120 °C under vacuum (<20 Pa) and reacted for 1 hour. The mixture reacted in vacuum was then returned to 25 °C under a nitrogen atmosphere, and tris(trimethylsilyl)phosphine (0.2 mmol) was added. The mixture was then heated to approximately 300 °C and reacted for 10 minutes. The reaction mixture was cooled to 25 °C, and octanoic acid chloride (0.45 mmol) was added. The mixture was heated to approximately 250 °C for 30 minutes, and then cooled to 25 °C. -Shell formation- The mixture was then heated to 200°C, and 0.75 mL of Zn precursor solution and 0.3 mmol of trioctylphosphine selenide were added simultaneously. The mixture was allowed to react for 30 minutes to form a ZnSe shell on the surface of the InP-based semiconductor nanoparticles. 1.5 mL of Zn precursor solution and 0.6 mmol of trioctylphosphine sulfide were then added, and the mixture was heated to 250°C and allowed to react for 1 hour to form a ZnS shell. -Purification of semiconductor nanoparticles- The reaction solution of semiconductor nanoparticles synthesized as described above was added to acetone, mixed thoroughly, and then centrifuged. The centrifugal acceleration was set to 4000 G. The precipitate was collected, and normal hexane was added to the precipitate to prepare a dispersion. This procedure was repeated several times to obtain purified semiconductor nanoparticles. (Preparation of semiconductor nanoparticle composites) A semiconductor nanoparticle 1-octadecene dispersion was prepared by dispersing the purified semiconductor nanoparticles in 1-octadecene in a flask at a mass ratio of 10%. 10.0 g of the prepared semiconductor nanoparticle 1-octadecene dispersion was placed in a flask, and 3.5 g of triethylene glycol monomethyl thiol (TEG-SH) and 0.5 g of dodecane thiol were added. The mixture was stirred at 110°C for 60 minutes under a nitrogen atmosphere and then cooled to 25°C to obtain a semiconductor nanoparticle composite. The reaction solution was transferred to a centrifuge tube and centrifuged at 4000 G for 20 minutes, resulting in separation into a transparent 1-octadecene phase and a semiconductor nanoparticle composite phase. The 1-octadecene phase was removed, and the remaining semiconductor nanoparticle composite phase was collected. -Purification of semiconductor nanoparticle composites- 5.0 mL of acetone was added to the obtained semiconductor nanoparticle composite phase to prepare a dispersion. 50 mL of normal hexane was added to the obtained dispersion, and the mixture was centrifuged at 4000 G for 20 minutes. After centrifugation, the clear supernatant was removed and the precipitate was collected. This procedure was repeated several times to obtain a purified semiconductor nanoparticle composite.

[0067] (measurement) The optical properties of the obtained semiconductor nanoparticle composite were measured. As mentioned above, the optical properties were measured using a quantum efficiency measurement system (QE-2100, manufactured by Otsuka Electronics Co., Ltd.). The obtained semiconductor nanoparticle composite was dispersed in PGMEA (propylene glycol monomethyl ether acetate), and an emission spectrum was obtained by irradiating it with a single light of 450 nm as excitation light. The fluorescence quantum efficiency (QY) and full width at half maximum (FWHM) were calculated from the emission spectrum after re-excitation correction, which was obtained by removing the re-excitation fluorescence emission spectrum corresponding to the fluorescence emission due to re-excitation from the obtained emission spectrum.

[0068] (Semiconductor nanoparticle composite dispersion) The purified semiconductor nanoparticle composite was heated to 550°C by differential thermogravimetry (DTA-TG), held at that temperature for 10 minutes, and then cooled. The residual mass after analysis was taken as the mass of the semiconductor nanoparticles, and this value was used to determine the mass ratio of the semiconductor nanoparticles to the semiconductor nanoparticle composite. With reference to the above mass ratio, PGMEA (SP value 9.41) was added to the semiconductor nanoparticle composite so that the mass fraction of the semiconductor nanoparticles in the semiconductor nanoparticle composite dispersion became 1 mg / mL, thereby obtaining a semiconductor nanoparticle composite dispersion. This semiconductor nanoparticle composite dispersion was placed in an optical cell with an optical path length of 1 cm, and the absorbance at 450 nm was measured using a visible-ultraviolet spectrophotometer (V670 manufactured by JASCO Corporation). This was used to measure the OD 450 It was decided.

[0069] (Semiconductor nanoparticle composite composition) 89 parts by mass of isobornyl acrylate, 10 parts by mass of trimethylolpropane triacrylate, and 1 part by mass of 2,2-dimethoxy-2-phenylacetophenone were mixed to obtain an ultraviolet-curable resin. The ultraviolet-curable resin and semiconductor nanoparticle composite were mixed to obtain a semiconductor nanoparticle composite composition. At this time, the mass fraction of semiconductor nanoparticles in the semiconductor nanoparticle composite composition was 40% by mass.

[0070] (Semiconductor nanoparticle composite cured film) The aforementioned semiconductor nanoparticle composite composition was formed into a film on glass by spin coating, and the solvent was evaporated by heating at 90°C for 3 minutes. After photo-curing by irradiation with ultraviolet light in the atmosphere, the film was baked at 200°C for 20 minutes to obtain a semiconductor nanoparticle composite cured film. The absorbance per 5 μm of the obtained semiconductor nanoparticle composite cured film was measured using a visible-ultraviolet spectrophotometer (V670 manufactured by JASCO Corporation) by irradiating light with 450 nm wavelength from the normal direction of the semiconductor nanoparticle composite cured film, as in the case of the semiconductor nanoparticle composite dispersion. The absorbance at this time is shown in the table. Furthermore, similarly to the semiconductor nanoparticle composite, the fluorescence quantum efficiency of the semiconductor nanoparticle composite cured film was measured using a quantum efficiency measurement system (QE-2100, manufactured by Otsuka Electronics Co., Ltd.). The fluorescence quantum efficiency of the semiconductor nanoparticle composite cured film is shown in Tables 1 to 3.

[0071] [Example 2] In the method for producing the semiconductor nanoparticle composite described in Example 1 above, 4.0 g of methyl 3-mercaptopropionate (MPA-Me) was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0072] [Example 3] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 4.0 g of 2-mercaptoethanol was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0073] [Example 4] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of methyl dihydrolipoate produced by the method described below was added in place of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. - Preparation of methyl dihydrolipoate - 2.1 g (10 mmol) of dihydrolipoic acid was dissolved in 20 mL (49 mmol) of methanol, and 0.2 mL of concentrated sulfuric acid was added. The solution was refluxed for 1 hour under a nitrogen atmosphere. The reaction solution was diluted with chloroform, and the solution was extracted sequentially with 10% aqueous HCl, 10% aqueous Na2CO3, and saturated aqueous NaCl to recover the organic phase. The organic phase was concentrated by evaporation and purified by column chromatography using a hexane-ethyl acetate mixed solvent as the developing solvent to obtain methyl dihydrolipoate.

[0074] [Example 5] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of 6-mercaptohexyl acrylate produced by the method described below was added in place of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. - Preparation of 6-mercaptohexyl acrylate - 1.34 g (10 mmol) of 2-aminoethanethiol and 1.7 mL (12 mmol) of triethylamine were placed in a 100 mL round-bottom flask and dissolved in 30 mL of anhydrous dichloromethane. The solution was cooled to 0 °C, and under a nitrogen atmosphere, 0.81 mL (10 mmol) of acryloyl chloride was slowly added dropwise, taking care not to allow the solution temperature to exceed 5 °C. After the addition, the reaction solution was warmed to room temperature and stirred for 1 hour. The reaction solution was filtered, and the filtrate was diluted with chloroform. The filtrate was extracted with 10% aqueous HCl, 10% aqueous Na2CO3, and saturated aqueous NaCl, and the organic phase was recovered. The resulting organic phase was dried over magnesium sulfate, filtered, and concentrated by evaporation to obtain the desired 6-mercaptohexyl acrylate. To prevent intramolecular reaction between the mercapto and acrylic groups, the product was used immediately after purification for the preparation of semiconductor nanoparticle composites.

[0075] [Example 6] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of N-acetyl-N-(2-mercaptoethyl)propanamide produced by the method described below was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Furthermore, in the production of the semiconductor nanoparticle composite composition described in Example 1, the monomer was changed to a mixture of methacrylic acid and 2,2-azobis(2,4-dimethylvaleronitrile), and the crosslinking agent was changed to glycidyl methacrylate and PETA-SA (pentaerythritol triacrylate succinic acid modified product), respectively, to obtain a semiconductor nanoparticle composite composition. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. - Preparation of N-acetyl-N-(2-mercaptoethyl)propanamide - 1.2 g (10 mmol) of N-(2-sulfanylethyl)acetamide and 1.7 mL (12 mmol) of triethylamine were placed in a 100 mL round-bottom flask and dissolved in 30 mL of anhydrous dichloromethane. The solution was cooled to 0°C, and under a nitrogen atmosphere, 0.87 mL (10 mmol) of propanoyl chloride was slowly added dropwise, taking care not to allow the solution temperature to exceed 5°C. After the addition was complete, the reaction solution was warmed to room temperature and stirred for 2 hours. The reaction solution was filtered, and the filtrate was diluted with chloroform. The solution was extracted sequentially with 10% aqueous HCl, 10% aqueous Na2CO3, and saturated aqueous NaCl, and the organic phase was recovered. The organic phase was concentrated by evaporation and then purified by column chromatography using a hexane-ethyl acetate mixed solvent as the developing solvent to obtain N-acetyl-N-(2-mercaptoethyl)propanamide.

[0076] [Example 7] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of N-acetyl-N-(2-mercaptoethyl)propanamide was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Furthermore, in the production of the semiconductor nanoparticle composite composition, the monomer and crosslinking agent were changed to a thermosetting addition reaction type silicone resin, a transparent sealing resin for photodevices (model "SCR-1011(A / B)", manufactured by Shin-Etsu Silicones Co., Ltd.), mixed with liquid A and liquid B in a 50:50 (mass ratio), to obtain a semiconductor nanoparticle composite composition. In producing the semiconductor nanoparticle composite cured film, the semiconductor nanoparticle composite composition was applied to glass by spin coating and heated at 150°C for 5 hours to obtain a semiconductor nanoparticle composite cured film. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0077] [Example 8] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnS shell was changed to 1.0 mL, and the amount of trioctylphosphine sulfide was changed to 0.4 mmol / L. The average particle size (the aforementioned Heywood diameter) of the semiconductor nanoparticles obtained in this manner was measured by TEM and was found to be 3 nm. Furthermore, in the method for producing a semiconductor nanoparticle composite described in Example 1, 3.5 g of methyl dihydroxy acid was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0078] [Example 9] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnS shell was changed to 1.75 mL, and the amount of trioctylphosphine sulfide was changed to 0.7 mmol. The average particle size (the aforementioned Heywood diameter) of the resulting semiconductor nanoparticles was measured by TEM and was found to be 6 nm. Furthermore, in the method for producing semiconductor nanoparticle composites described in Example 1, 3.5 g of PEG-SH (polyethylene glycol monomethyl ether thiol) produced by the method described below was added instead of TEG-SH to obtain semiconductor nanoparticle composites. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. - Preparation of PEG-SH - A flask was charged with 210 g of methoxy PEG-OH (molecular weight 400) and 93 g of triethylamine, which were dissolved in 420 mL of tetrahydrofuran (THF). The solution was cooled to 0°C, and 51 g of methanesulfonic acid chloride was slowly added dropwise under a nitrogen atmosphere, taking care not to allow the reaction temperature to exceed 5°C. The reaction solution was then warmed to room temperature and stirred for 2 hours. This solution was extracted with a chloroform-water system, and the organic phase was recovered. The resulting solution was dried over magnesium sulfate, the magnesium sulfate was removed by filtration, and the filtrate was concentrated by evaporation to obtain an oily intermediate. This was transferred to another flask, and 400 mL of 1.3 M aqueous thiourea solution was added under a nitrogen atmosphere. The solution was refluxed for 2 hours, after which 21 g of NaOH was added, and the mixture was refluxed for an additional 1.5 hours. The reaction solution was cooled to room temperature and neutralized with 1 M aqueous HCl until the pH reached 7. The resulting solution was extracted with a chloroform-water system to obtain the desired ligand (PEG-SH, molecular weight 400).

[0079] [Example 10] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of PEG-SH was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0080] [Example 11] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnS shell was changed to 2.0 mL, and the amount of trioctylphosphine sulfide was changed to 0.9 mmol. The average particle size (the aforementioned Heywood diameter) of the resulting semiconductor nanoparticles was measured by TEM and was found to be 7 nm. Furthermore, in the method for producing a semiconductor nanoparticle composite described in Example 1, 3.5 g of N-acetyl-N-(2-mercaptoethyl)propanamide was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0081] [Example 12] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnS shell was changed to 3.75 mL, and the amount of trioctylphosphine sulfide was changed to 1.5 mmol. The average particle size (the aforementioned Heywood diameter) of the resulting semiconductor nanoparticles was measured by TEM and was found to be 10 nm. Furthermore, in the method for producing a semiconductor nanoparticle composite described in Example 1, 3.5 g of N-acetyl-N-(2-mercaptoethyl)propanamide was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0082] [Example 13] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnS shell was changed to 3.75 mL, and the amount of trioctylphosphine sulfide was changed to 1.5 mmol. The average particle size (the aforementioned Heywood diameter) of the resulting semiconductor nanoparticles was measured by TEM and was found to be 13 nm. Furthermore, in the method for producing a semiconductor nanoparticle composite described in Example 1, 3.5 g of PEG-SH was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0083] [Example 14] In the method for producing semiconductor nanoparticles described in Example 1 above, the amount of Zn precursor solution used to form the ZnSe shell was changed to 1.5 mL, and the amount of trioctylphosphine selenide was changed to 0.6 mmol / L. Furthermore, the amount of Zn precursor solution used to form the ZnS shell was changed to 4.5 mL, and the amount of trioctylphosphine sulfide was changed to 1.8 mmol / L. The average particle size (the aforementioned Heywood diameter) of the resulting semiconductor nanoparticles was measured by TEM and found to be 13 nm. Furthermore, in the method for producing a semiconductor nanoparticle composite described in Example 1, 3.5 g of PEG-SH was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated.

[0084] [Example 15] In the method for producing the semiconductor nanoparticle composite described in Example 1 above, 6.5 g of PEG-COOH (molecular weight 750) produced by the method described below was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. When a semiconductor nanoparticle composite cured film was prepared in the same manner as in Example 1, the film did not cure. - Preparation of PEG-COOH (molecular weight 750) - Methoxy PEG-OH (molecular weight 700, 26 g) was dissolved in toluene (100 mL) at 60 °C, and 4.2 g of potassium tert-butoxide was added and the reaction mixture was allowed to react for 6 hours. Subsequently, 5.5 g of ethyl bromoacetate was added to the mixture, and the hydroxyl groups in the PEG were protected with ethyl acetate groups. The mixture was filtered, and the filtrate was precipitated in diethyl ether. The precipitate was dissolved in 1 M NaOH solution (40 mL), and NaCl (10 g) was added. The mixture was stirred at room temperature for 1 hour to remove the ethyl groups at the terminals of the PEG. The pH of this solution was adjusted to 3.0 by adding 6 M HCl. The resulting solution was extracted with a chloroform-water system to obtain PEG-COOH with a molecular weight of 750.

[0085] [Example 16] In the method for producing the semiconductor nanoparticle composite described in Example 1 above, 8.5 g of PEG-COOH (molecular weight 1000) produced by the method described below was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. When a semiconductor nanoparticle composite cured film was prepared in the same manner as in Example 1, the film did not cure. - Preparation of PEG-COOH (molecular weight 1000) - Methoxy PEG-OH (molecular weight 950, 36 g) was dissolved in toluene (100 mL) at 60 °C, and 4.2 g of potassium tert-butoxide was added. The mixture was then reacted for 6 hours. 5.5 g of ethyl bromoacetate was then added to the mixture, and the hydroxyl groups in the PEG were protected with ethyl acetate groups. The mixture was filtered, and the filtrate was precipitated in diethyl ether. The precipitate was dissolved in 1 M NaOH solution (40 mL), and NaCl (10 g) was added. The mixture was stirred at room temperature for 1 hour to remove the ethyl groups at the ends of the PEG. The pH of this solution was adjusted to 3.0 by adding 6 M HCl. The resulting solution was extracted with a chloroform-water system to obtain PEG-COOH with a molecular weight of 1,000.

[0086] [Example 17] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 6.5 g of PEG-COOH(750) was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. Other than that, in the same manner as in Example 1, a semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, a semiconductor nanoparticle composite composition, and a semiconductor nanoparticle composite cured film were prepared, and their physical properties were evaluated. The upper limit of the mass fraction of semiconductor nanoparticles in the semiconductor nanoparticle composite composition and the semiconductor nanoparticle composite cured film was 25%.

[0087] [Example 18] In the method for producing a semiconductor nanoparticle composite described in Example 1 above, 3.5 g of N-acetyl-N-(2-mercaptoethyl)propanamide was added instead of TEG-SH to obtain a semiconductor nanoparticle composite. A semiconductor nanoparticle composite, a semiconductor nanoparticle composite dispersion, and a semiconductor nanoparticle composite composition were prepared and their physical properties were evaluated in the same manner as in Example 1. An attempt was made to prepare a semiconductor nanoparticle composite cured film in the same manner as in Example 1, without adding a crosslinking agent, but the film did not cure.

[0088] [Example 19] In the method for producing the semiconductor nanoparticle composite described in Example 1 above, the procedure was changed as follows. 10.0 g of a semiconductor nanoparticle hexane dispersion, in which purified semiconductor nanoparticles were dispersed in hexane to a mass ratio of 10% by mass, was placed in a flask, and 10 mL of formamide and 10 mL of a 0.5% by mass ammonium sulfide aqueous solution were added. The mixture was stirred for 10 minutes at room temperature under a nitrogen atmosphere to obtain a reaction solution containing semiconductor nanoparticle composites. The reaction solution was transferred to a centrifuge tube, 40 mL of acetone was added, and the mixture was centrifuged at 4000 G for 20 minutes, resulting in separation into a clear solution layer and a semiconductor nanoparticle composite phase. The clear solution phase was removed, and the remaining semiconductor nanoparticle composite phase was recovered. Acetone was replaced with chloroform and normal hexane with acetone in the purification method for semiconductor nanoparticle composite described in Example 1. The resulting semiconductor nanoparticle composite had a fluorescence quantum efficiency of 15% and a half-value width of 45 nm. The resulting semiconductor nanoparticle composite did not disperse in PGMEA, and furthermore, the semiconductor nanoparticle composite did not disperse in isobornyl acrylate.

[0089] For each of the semiconductor nanoparticle composites in the above examples, when mixing the monomer and semiconductor nanoparticle composite in the method for producing the semiconductor nanoparticle composite composition, 10 mass% of titanium oxide (diameter 300 nm) was mixed to obtain a semiconductor nanoparticle composite composition, and the semiconductor nanoparticle composite composition was then cured to obtain a scattering agent-containing semiconductor nanoparticle composite cured film. The absorbance of the scattering agent-containing semiconductor nanoparticle composite cured film was measured using the method described above. The results are shown in Tables 1 to 3.

[0090] The meanings of the abbreviations shown in Table 1 are as follows: DDT: Dodecanethiol OA: Oleic acid

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3] [Explanation of symbols]

[0094] 1 blue LED 3 LCD 7 QD Patterning(R) 8 QD patterning (G) 9 Diffusion Layer 101 Blue LED 102 QD Film 103 LCD 104 Color Filter(R) 105 Color Filter (G) 106 Color Filter (B)

Claims

1. A semiconductor nanoparticle composite in which a ligand is coordinated to the surface of a semiconductor nanoparticle, the semiconductor nanoparticles are core-shell particles having a core containing InP and a shell containing Group II and Group VI elements that covers at least a portion of the core; the ligand comprises an organic group and a coordinating group; the organic group has one or more groups selected from an ether group, an ester group, and an amide group; the molecular weight of the ligand is 50 or more and 600 or less; a mass ratio of the ligand to the semiconductor nanoparticles (ligand / semiconductor nanoparticles) of 0.10 to 0.40; Semiconductor nanoparticle composites.

2. The coordinating group includes a mercapto group. The semiconductor nanoparticle composite of claim 1 .

3. The semiconductor nanoparticle composite has a fluorescence quantum efficiency of 80% or more. The semiconductor nanoparticle composite according to claim 1 or 2.

4. The semiconductor nanoparticle composite has an emission spectrum having a half-width of 38 nm or less. The semiconductor nanoparticle composite according to any one of claims 1 to 3.

5. The molecular weight of the ligand is 50 or more and 450 or less. The semiconductor nanoparticle composite according to any one of claims 1 to 4.

6. A semiconductor nanoparticle composite dispersion liquid comprising the semiconductor nanoparticle composite according to any one of claims 1 to 5.

7. A semiconductor nanoparticle composite composition comprising the semiconductor nanoparticle composite according to any one of claims 1 to 5.

8. A semiconductor nanoparticle composite cured film comprising the semiconductor nanoparticle composite according to any one of claims 1 to 5.

9. A semiconductor nanoparticle composite patterned film comprising the semiconductor nanoparticle composite according to any one of claims 1 to 5.

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