Structure with luminescent nanostructures

Abstract

A proposed composition comprising: a support matrix; several photoluminescent nanostructures distributed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] The present application is based on and claims priority under 35 USC 119(e) of U.S. Preliminary Patent Application No. 63 / 443,281, filed on February 3, 2023, entitled STRUCTURE WITH LUMINESCENT NANO-STRUCTURES, of U.S. Preliminary Patent Application No. 63 / 454,199, filed on March 23, 2023, entitled STRUCTURE WITH LUMINESCENT NANO-STRUCTURES, of U.S. Preliminary Patent Application No. 63 / 516,381, filed on July 28, 2023, entitled COMPOSITION WITH LUMINESCENT NANO-STRUCTURES, and of U.S. Preliminary Patent Application No. 63 / 607,879, filed on December 8, 2023, entitled SUPPLEMENTARY AMINE ADDITIVES FOR QUANTUM-DOT PHOTOLUMINESCENCE STABILITY, the entirety of which is hereby incorporated by reference for all purposes. BACKGROUND

[0002] Poor operational stability of quantum dots under photoexcitation in humid environments can be addressed by overlaying so-called "barrier layers" onto optical quantum dot (QP) film products, for example, QP resin layers, to reduce the QPs' exposure to moisture. This approach increases the thickness and cost of the QP layer and limits the availability of the resulting optical QP film.

[0003] Therefore, eliminating barrier layers may be desirable to reduce manufacturing costs and complexity. However, this can expose QPe to conditions (such as humidity and / or air) that degrade performance. SUMMARY

[0004] One disclosed embodiment provides a composition comprising: a support matrix; several photoluminescent nanostructures distributed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer.

[0005] In some such embodiments, the multiple photoluminescent nanostructures feature one or more indium phosphide (InP) based quantum dots, silver indium gallium sulfide (AIGS) based quantum dots, or cadmium selenide (CdSe) based quantum dots.

[0006] Alternatively or additionally, in some such embodiments, at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer and the hindered amine stabilizer can be stabilizing additives, and the stabilizing additives and the multiple photoluminescent nanostructures can be distributed together as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives.

[0007] Alternatively or additionally, in some such embodiments the composition may include a secondary antioxidant compound dispersed in the support matrix and configured to decompose at least one hydroperoxide.

[0008] Alternatively or additionally, in some such embodiments the secondary antioxidant compound may contain phosphorus and / or sulfur.

[0009] Alternatively or additionally, in some such embodiments the secondary antioxidant compound may have the following structure: A-[(L)nR]m, where A is a structural unit that exhibits secondary antioxidant functionality; Each L is a linker group selected from phenyl, -O- and -S-; n is 0 or 1; Each R is independently a substituted or unsubstituted C6-40 hydrocarbon group; and m is a number from 1 to 6.

[0010] Alternatively or additionally, in some such embodiments, the hindered amine stabilizer, the at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer and the secondary antioxidant can be stabilizing additives, and the multiple photoluminescent nanostructures and the stabilizing additives together can be distributed as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives.

[0011] Alternatively or additionally, in some such embodiments the composition may include an additional base dispersed in the support matrix.

[0012] Alternatively or additionally, in some such embodiments the additional base may contain melamine or a melamine derivative.

[0013] Alternatively or additionally, in some such embodiments the additional base can comprise a melamine-based product of a Mannich condensation.

[0014] Alternatively or additionally, in some such embodiments the additional base may comprise a salt of melamine or a melamine derivative.

[0015] Alternatively or additionally, in some such embodiments the additional base may comprise a triazine compound.

[0016] Alternatively or additionally, in some such embodiments the additional base may comprise a cyanamide condensate.

[0017] Alternatively or additionally, in some such embodiments the additional base may be an aromatic imine base.

[0018] Alternatively or additionally, in some such embodiments the additional base may comprise a metal carbonate.

[0019] Alternatively or additionally, in some such embodiments the metal carbonate can be a lithium carbonate.

[0020] Alternatively or additionally, in some such embodiments, the at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer, the hindered amine stabilizer and the additional base can be stabilizing additives, wherein the stabilizing additives and the multiple photoluminescent nanostructures can be distributed together as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives.

[0021] Alternatively or additionally, in some such embodiments the composition may also include a carrier particle.

[0022] Alternatively or additionally, in some such embodiments, the carrier particle may comprise a material for scattering light of at least one of: a wavelength absorbed by the luminescent nanostructures, or a wavelength emitted by the luminescent nanostructures.

[0023] Alternatively or additionally, in some such embodiments the carrier particle can have a band gap of more than 3 eV.

[0024] Alternatively or additionally, in some such embodiments, the carrier particle may comprise at least one of: an inorganic material, a metal oxide, a metal sulfide, or one or more of SiO2, TiO2, ZnO, or ZnS.

[0025] Alternatively or additionally, in some such embodiments the composition may also have a coating that at least partially surrounds the carrier particle.

[0026] Alternatively or additionally, in some such embodiments the coating can consist of at least one of: a) at least one material selected from the group consisting of: an alkoxysilane with a linear or branched alkyl substituent; an alkoxysilane with at least one phenyl, mercapto or amino substituent; an alkoxysilane with at least one crosslinkable reactive functional group; an alkoxysilane with at least one halide functional group; a tetraalkoxysilane; an alkali, alkaline earth or transition metal silicate; or a group (IV) or transition metal alkoxide; and / or b) at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer; a styrene-ethylene / propylene-styrene copolymer; polyvinylidene dichloride or a high-boiling wax.

[0027] Alternatively or additionally, in some such embodiments the coating may comprise a silanized coordination polymer.

[0028] Alternatively or additionally, in some such embodiments the coating may comprise a silanized coordination polymer, which is the reaction product of an alkylalkoxysilane and a metal thiolate.

[0029] Alternatively or additionally, in some such embodiments the coordination polymer may contain a metal thiolate.

[0030] In another embodiment, a screen is provided. The screen comprises a hardened composition including a support matrix; several photoluminescent nanostructures dispersed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer.

[0031] In some such embodiments, the support matrix comprises a thermoplastic material or a precursor to a thermoplastic material, and wherein the hardened composition further comprises a secondary antioxidant compound dispersed in the support matrix and configured to decompose at least one hydroperoxide.

[0032] In another embodiment, a display device is provided. The display device includes a screen comprising a hardened composition. The hardened composition comprises a support matrix; several photoluminescent nanostructures dispersed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer.

[0033] In some such embodiments, the screen has a substantially planar solid structure and the hardened composition further comprises an additional base dispersed in the support matrix.

[0034] Alternatively or additionally, in some such embodiments the additional base may comprise a melamine-based product of a Mannich condensation. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 schematically shows a perspective view of a slide of an exemplary embodiment. Fig. 2 and Fig. Figure 3 schematically shows a sectional view of a structure of an exemplary embodiment. Fig. 4A and Fig. Figure 4B schematically shows a side cross-section of a device of various embodiments. Fig. 5A and Fig. Figure 5B shows performance data for luminescent nanostructures within structures of exemplary embodiments. Fig. 6A to Fig. Figure 6D shows performance data for luminescent nanostructures within structures of exemplary embodiments. Fig. Figure 7A shows the molecular structure of 2,2,6,6-tetramethylpiperidin-4-yl, which can be used here as a hindered amine light stabilizer. Fig. Figure 7B shows the molecular structures of melamine, which can be used here as an additional base. Fig. Figure 7C shows the molecular structure of a substituted melamine compound of an exemplary embodiment, which can be used here as an additional base. Fig. Figure 8 shows performance data for exemplary photoluminescent nanostructures used in the embodiments and comparison examples herein. Fig. 9A, Fig. 9B, Fig. 10A and Fig.Figure 10B shows performance data for exemplary photoluminescent nanostructures used in the embodiments. Fig. Figure 11 shows selected reliability data for green and red emitting QPe under various test conditions. Fig. 12A and Fig. Figure 12B shows aspects of a display device of an exemplary embodiment. Fig. Figure 13 shows aspects of an electronic device of an exemplary embodiment. DETAILED DESCRIPTION

[0035] In the embodiments described herein, structures are provided in which luminescent nanostructures, such as quantum dots, are arranged within a coating that at least partially surrounds a support particle. The coating protects the nanostructures at least partially from, for example, moisture and / or air, which could otherwise adversely affect the structural and / or optical properties of the nanostructure. The support particle can also protect the nanostructures at least partially from environmental factors such as moisture and / or air. In this way, the coating and / or the support particle can be considered a barrier material or a barrier layer. Therefore, a separate barrier film (for example, in a so-called quantum dot enhancement film (QPVF film)) may not be necessary to protect nanostructures from moisture and / or air.

[0036] Furthermore, the coating and the carrier particle can also serve to distance the nanostructures (each as part of a structure and / or of neighboring structures) from each other, which reduces the aggregation and quenching of their optical properties.

[0037] In other embodiments described herein, structures are provided in which one or more luminescent nanostructures are located within a material, wherein the material is formed from at least one material selected from the group consisting of: an alkoxysilane with a linear or branched alkyl substituent; an alkoxysilane with at least one phenyl, mercapto, or amino substituent; an alkoxysilane with at least one crosslinkable reactive functional group; an alkoxysilane with at least one halide functional group; a tetraalkoxysilane; an alkali, alkaline earth, or transition metal silicate; or a group (IV) or transition metal alkoxide; and at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer;The material is selected from a styrene-ethylene / propylene-styrene copolymer, polyvinylidene dichloride, or a high-boiling-point wax. It provides protection against, for example, moisture and / or air, which could otherwise adversely affect the structural and / or optical properties of the nanostructure. The material can also serve to space the nanostructures (each as part of a structure and / or of adjacent structures) apart, thus reducing aggregation and the quenching of their optical properties.

[0038] Examples of embodiments are now described with reference to the drawings. In the following description, a feature of a later drawing figure may correspond to a feature of an earlier drawing figure.

[0039] In some embodiments, the coating at least partially surrounds a carrier particle (and in some embodiments completely surrounds the carrier particle). A structure 203 of such embodiments mentioned herein is now described with reference to Fig. 2 described. A carrier particle 211 is surrounded by a coating 213 containing luminescent nanostructures 215.

[0040] The carrier particle is, for example, a particle or body that carries the coating and the luminescent nanostructures within the coating. Thus, the carrier particle itself may not be luminescent and may not possess a luminescent nanostructure. In some embodiments, the carrier particle may be approximately spherical (e.g., spherical within acceptable manufacturing tolerances). The coating is, for example, a material that coats or covers the carrier particle as a layer. Therefore, in embodiments, the structure can be assumed to have a core-shell structure, with the core corresponding to the carrier particle and the shell corresponding to the coating. The coating may be in direct contact with the carrier particle, or one or more other layers may be arranged between the carrier particle and the coating.In some embodiments, the coating thickness is approximately uniform, so that the resulting structure is approximately spherical. In other embodiments, the coating thickness is not uniform; however, in such embodiments, the relatively small thickness of the coating and the approximately spherical nature of the carrier particle mean that the resulting structure can also be approximately spherical. This can facilitate the dispersion and / or mixing of the structures in a carrier material (explained later) for use, for example, in a film or other element of a display device. In other embodiments, the carrier particle and / or the particle can be non-spherical, for example, cubic.

[0041] By adjusting the concentration and dispersion of the nanostructures within the coating, the distance between nanostructures within the coating can be set according to desired light absorption and / or light emission properties.

[0042] The carrier particle 211 also determines the spacing between nanostructures, e.g., within opposing sections of the coating. Furthermore, multiple structures may tend to reduce the concentration of the nanostructures, as the larger structures are packed inefficiently compared to freely dispersed nanostructures, which tend to aggregate more densely. Additionally, and without being bound to the theory, it is assumed that the presence of the carrier particle further limits exposure to moisture and / or air, since the coating is exposed to moisture / air on the outer surface rather than the inner surface.

[0043] In some embodiments, the material, shape, and / or size of the support particle can be selected to create the desired optical functionality. For example, the support particle may have a material for scattering light, e.g., light of a wavelength absorbed by the nanostructures and / or light of a wavelength emitted by the luminescent nanostructures, or may be substantially composed of such a material (e.g., formed entirely within acceptable purity tolerances). This light-scattering property increases, for example, the effective path length near the luminescent nanostructures, thereby increasing the coincidence of excitation photons with the nanostructures and improving the downconversion efficiency. In some of these embodiments, the material forming the support particle has a band gap of more than approximately 3 eV (electron volts).With a band gap in this region, the carrier particles do not significantly absorb excitation with relatively short wavelengths (e.g., blue), but primarily act as scattering particles. The carrier particle can have a maximum dimension, e.g., a diameter, between approximately 100 nm (nanometers) and approximately 10 µm (micrometers) (e.g., less than approximately 5 µm, 3 µm, 2 µm, 1.8 µm, or 1.5 µm). A soft upper limit on the dimension ensures efficient scattering of relatively short-wavelength light as well as optical uniformity in the thin films. In exemplary embodiments, the carrier particle is solid and / or in the solid phase. In some exemplary embodiments, the carrier particle is made of an inorganic material. And in some embodiments, the carrier particle has a metal oxide or sulfide, e.g. one or more of SiO2 (silicon dioxide), TiO2 (titanium dioxide), ZnO (zinc oxide) or ZnS (zinc sulfide).

[0044] The coating 213 is formed from a material that is optically transparent, at least for one or more wavelengths of the input (excitation) and output (emission) light of the luminescent nanostructures.

[0045] In some embodiments, the coating may comprise or be derived from at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer; a styrene-ethylene / propylene-styrene copolymer; polyvinylidene dichloride; or a high-boiling-point wax (e.g., a wax with a boiling point greater than approximately 100 °C, 150 °C, 200 °C, or 250 °C). The extrusion and / or film-making process typically takes place at a relatively high temperature, so a wax with a relatively high boiling point is advantageous. Such coating materials repel water, at least partially (and can thus be considered hydrophobic). In some embodiments, the coating comprises a coordination polymer derived from a metal thiolate and / or a metal carboxylate.

[0046] In some embodiments, the coating can consist of at least one of: a) at least one material selected from the group consisting of: an alkoxysilane with a linear or branched alkyl substituent; an alkoxysilane with at least one phenyl, mercapto or amino substituent; an alkoxysilane with at least one crosslinkable reactive functional group; an alkoxysilane with at least one halide functional group; a tetraalkoxysilane; an alkali, alkaline earth or transition metal silicate; or a group (IV) or transition metal alkoxide; and / or b) at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer; a styrene-ethylene / propylene-styrene copolymer; polyvinylidene dichloride or a high-boiling wax.

[0047] Such coating materials repel water at least partially (and can therefore be considered hydrophobic).

[0048] In some embodiments, the coating may be formed from at least one material selected from the list in paragraph a) and not b) or b) and not a). In some embodiments, the coating may be formed from at least one material selected from the list in paragraph a) and at least one material selected from the list in paragraph b) and possibly from another list.

[0049] An example of an alkoxysilane with a linear or branched alkyl substituent is hexyltrimethoxysilane. Examples of an alkoxysilane with at least one phenyl, mercapto, or amino substituent include phenyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, and 3-aminopropyltrimethoxysilane. In some embodiments, the crosslinkable reactive functional group is an unsaturated terminal group, such as terminal alkenes, acrylates, methacrylates, etc. Examples of alkoxysilanes with at least one crosslinkable reactive functional group include vinyltrimethoxysilane, 3-(trimethoxysilyl)propyl acrylate, and 3-(trimethoxysilyl)propyl methacrylate, and the like. An example of an alkoxysilane with at least one halide functional group is chlorotrimethoxysilane. Examples of tetraalkoxysilanes include tetramethyl orthosilicate and tetraethyl orthosilicate.

[0050] In some embodiments, the metal thiolate or metal carboxylate is able to form a coordination polymer, such as zinc dodecane thiolate. In some embodiments, the fluoropolymer is a fluorocarbon polymer that is fully or partially fluorinated along the carbon backbone, such as PTFE.

[0051] In some embodiments, the weight ratio a:b of the components listed in the preceding paragraphs a) and b) may be in the range of approximately 1:50 to approximately 2:1. In some embodiments, the weight ratio may be in the range of approximately 1:3 to approximately 1:7, and preferably in the range of 1:4 to approximately 1:6. In some embodiments, the weight ratio may be approximately 1:5.

[0052] In some embodiments, the coating comprises a silanized coordination polymer, preferably a silanized coordination polymer that is the reaction product of an alkylalkoxysilane and a metal thiolate, and in some embodiments a silanized coordination polymer that is the reaction product of a linear alkylalkoxysilane and a metal thiolate. In some embodiments, the coating can be formed from an alkylalkoxysilane and a metal thiolate with a weight ratio of alkylalkoxysilane to metal thiolate of approximately 1:5. In some cases, the coating can be formed from hexyltrimethoxysilane and zinc dodecane thiolate.

[0053] In some embodiments, the silanized coordination polymer can be the reaction product of an alkylalkoxysilane and a metal thiolate in the presence of a surfactant. In some such embodiments, the surfactant can be an anionic surfactant containing a sulfate, sulfonate, phosphate, and / or carboxylate group. In certain embodiments, the anionic surfactant can be an alkyl sulfate, such as ammonium dodecyl sulfate and sodium dodecyl sulfate, or an alkyl ether sulfate, such as sodium laureth sulfate and sodium myreth sulfate. In some certain embodiments, the anionic surfactant can be sodium dodecyl sulfate. The presence of a surfactant during the reaction of an alkylalkoxysilane with a metal thiolate can, in some embodiments, improve the emission brightness, emission power conservation, and / or the emission wavelength stability over time.

[0054] In some embodiments, the thickness 221 of the coating applied to a carrier particle is between about 10 nm and about 500 nm, preferably between about 10 nm and about 300 nm or about 200 nm. (The thickness refers, for example, to the distance measured from the contact point of the coating with the surface of the carrier particle to the outer surface of the coating, measured orthogonally to the surface of the carrier particle.)

[0055] In some embodiments, the weight ratio of the luminescent nanostructures 215 to the coating material 213 is in the range of approximately 1:1 to approximately 1:30. The charge of the luminescent nanostructures is selected, for example, to achieve the required light emission intensity, which is also influenced by the quantum efficiency of the nanostructures. In some embodiments, the weight ratio of the carrier particle to the coating (including the nanostructures within the coating) is in the range of approximately 1:1 to 1:2 and can be approximately 2:3 in some embodiments.

[0056] In some embodiments, the maximum dimension, for example a diameter 219, of the structure 203 is up to about 10 µm, preferably up to about 5 µm, 3 µm or 2 µm. Structures with a maximum dimension of less than about 2 µm can be more easily integrated into a film while maintaining the optical uniformity of that film.

[0057] In some embodiments, the luminescent nanostructures 215 are photoluminescent. That is, incident light excites the nanostructures, which then luminesce at a longer wavelength. In some embodiments, the luminescent nanostructures are quantum dots, and in some embodiments, the quantum dots comprise at least one of: zinc telluride selenide (ZnTeSe), zinc telluride (ZnTe), zinc selenide (ZnSe), zinc sulfide (ZnS), indium phosphide (InP), indium gallium phosphide (InGaP), indium arsenide (InAs), indium zinc phosphide (InZnP), indium arsenide (InAs), indium arsenide phosphide (In-AsP), indium gallium arsenide phosphide (InGaAsP), silver indium gallium sulfide (AgInGaS or AIGS), copper indium sulfide (CuInS or CIS), copper indium gallium selenide (CuInGaSe or CIGS), cadmium selenide (CdSe), cadmium sulfide (CdS). Cadmium telluride (CdTe), cadmium selenide telluride (CdSeTe), cadmium zinc selenide (CdZnSe), molybdenum sulfide (MoS) or an alloy thereof.The quantum dots can have a core-shell structure, as will be explained later. The quantum dots can be configured to absorb incident blue light and emit red or green light.

[0058] In some other embodiments, the structure comprises a material with one or more luminescent nanostructures therein. A structure 303 of such embodiments mentioned herein is now described with reference to Fig. Figure 3 describes a material 313 with several luminescent nanostructures 315 embedded therein. In other embodiments, there may be only one luminescent nanostructure 315 per structure in the material. In some embodiments, the material can be described as a barrier material.

[0059] In such embodiments without a support particle, the structure can, for example, be approximately spherical. In some embodiments, it can be a material film containing multiple nanostructures.

[0060] In such embodiments (without a carrier particle), the material is formed from: a) at least one material selected from the group consisting of: an alkoxysilane with a linear or branched alkyl substituent; an alkoxysilane with at least one phenyl, mercapto or amino substituent; an alkoxysilane with at least one crosslinkable reactive functional group; an alkoxysilane with at least one halide functional group; a tetraalkoxysilane; an alkali, alkaline earth or transition metal silicate; or a group (IV) or transition metal alkoxide; and b) at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer; a styrene-ethylene / propylene-styrene copolymer; polyvinylidene dichloride or a high-boiling wax.

[0061] In some embodiments, the metal thiolate or metal carboxylate is able to form a coordination polymer, such as zinc dodecane thiolate. Accordingly, the “coordination polymer” herein may optionally comprise a metal thiolate. In some embodiments, the fluoropolymer is a fluorocarbon polymer that is wholly or partially fluorinated along the carbon backbone, such as PTFE. More generally, at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer may be referred to as a “stabilizing macromolecular additive” and is one of several types of stabilizing additives that may be used in an embodiment according to the present disclosure.

[0062] In some embodiments, the weight ratio a:b of the materials listed in the preceding paragraphs a) and b) may be in the range of approximately 1:50 to approximately 2:1. In some embodiments, the weight ratio may be in the range of approximately 1:3 to approximately 1:7, and preferably in the range of 1:4 to approximately 1:6. In some embodiments, the weight ratio may be approximately 1:5.

[0063] In some embodiments, the material comprises a silanized coordination polymer, preferably a silanized coordination polymer that is the reaction product of an alkylalkoxysilane and a metal thiolate, and in some embodiments a silanized coordination polymer that is the reaction product of a linear alkylalkoxysilane and a metal thiolate. In some embodiments, the coating can be formed from an alkylalkoxysilane and a metal thiolate with a weight ratio of alkylalkoxysilane to metal thiolate of approximately 1:5. In some cases, the coating can be formed from hexyltrimethoxysilane and zinc dodecane thiolate.

[0064] In some embodiments, the silanized coordination polymer can be the reaction product of an alkylalkoxysilane and a metal thiolate in the presence of a surfactant. In some such embodiments, the surfactant can be an anionic surfactant containing a sulfate, sulfonate, phosphate, and / or carboxylate group. In certain embodiments, the anionic surfactant can be an alkyl sulfate, such as ammonium dodecyl sulfate and sodium dodecyl sulfate, or an alkyl ether sulfate, such as sodium laureth sulfate and sodium myreth sulfate. In some certain embodiments, the anionic surfactant can be sodium dodecyl sulfate. The presence of a surfactant during the reaction of an alkylalkoxysilane with a metal thiolate can, in some embodiments, improve the emission brightness, emission power conservation, and / or the emission wavelength stability over time.

[0065] The foregoing description regarding the luminescent nanostructures, the structure size (for example, the maximum dimension 319) and the weight ratio of nanostructure to material all apply equally to these embodiments.

[0066] Methods for producing the structures of the exemplary embodiments described above will now be described, followed by a description of other compositions, films and devices that have the structures.

[0067] Structures containing support particles can be formed by a) mixing luminescent nanostructures with at least one of: a coating material or one or more precursors for the coating material to form a first mixture; b) contacting the first mixture with a support particle; and c) forming a coating from the first mixture, wherein the coating at least partially surrounds the support particle, with the luminescent nanostructures arranged within the coating.

[0068] In some embodiments, the method involves mixing luminescent nanostructures with a first precursor of the coating to form a first mixture, mixing support particles with a second precursor of the coating to form a second mixture, and combining the first and second mixtures. In some such embodiments, the first mixture can be provided in a solvent, such as a nonpolar organic solvent (e.g., toluene, chloroform), which is removed after combining the two mixtures.

[0069] In some processes where a support particle is present in the structure to be produced, a catalyst or binder can be added to the mixture, thereby promoting the adhesion of the coating to the support particle. In some embodiments, this can be tetrabutylammonium chloride or a similar compound. Other suitable materials include 1) reactive silanes, 2) multifunctional molecules with carboxy- or phosphonic acid, mercapto-, silyl-, amino-, allyl-, or acrylate structural units, and 3) acid / base catalysts, including quaternary ammonium salts and hydroxides. The bonding mechanism could be achieved through van der Waals-type interactions for QD ligands, functionalized scattering media, and binder molecules containing alkyl chain functional groups.Alternatively, covalent bonds between these same groups (ligands, surface functionalization, binders) could preferably be formed by thermally activated “click” type reactions (for example, thiols or amine / acid anhydride).

[0070] Structures without support particles can be formed by mixing luminescent nanostructures with the material or one or more precursors of the material. In some embodiments, the luminescent nanostructures can be contained in a solvent, which is subsequently removed. In some embodiments, the process can involve mixing luminescent nanostructures with a first precursor of the material to form a first mixture, followed by mixing with a second precursor of the material. In some such embodiments, the first mixture can be provided in a solvent, such as a nonpolar organic solvent, which is removed after the addition of the second precursor of the material.

[0071] A composition according to embodiments herein has several structures within a support material, each structure being a structure according to the preceding disclosure. In some embodiments, the support material is a thermoplastic material or a precursor of the thermoplastic material. In some embodiments, the thermoplastic material comprises polystyrene. In some embodiments, the support material is liquid. In other embodiments, the composition is a film with a solid support material, which in some embodiments has a thickness in the range of about 0.03 mm to about 3.0 mm, in the range of about 0.3 mm to about 3.0 mm, or in the range of about 0.5 mm to 1.5 mm or about 1.0 mm.

[0072] A film 100, which has several structures 103 of the embodiments described herein, is now described with reference to Fig.1 described. The structures 103 are supported by a support material 101. For example, the support material is a material such as a resin, a thermoplastic, or a powder that surrounds or encapsulates the structures and thereby supports them. The structures 103 have luminescent nanostructures that are configured to absorb light 107 and emit light 109. The structures 103 can, for example, be supported by the one described in Fig. 2 or Fig. The film can be of the type shown in section 3 and, in some embodiments, can be a mixture of these two structure types. The film can be referred to here as a quantum dot enhancement film (QPVF).

[0073] The structure and composition according to the embodiments described herein provide protection against, for example, moisture and / or air, which could otherwise adversely affect the structural and / or optical properties of the nanostructure. This protection is available throughout the entire handling and manufacturing of the film. In some embodiments, the structures can be integrated into films comprising cured resin substrates. In some embodiments, the structures can be integrated into films 100 formed from thermoplastic substrates 101, such as polystyrene. Other suitable thermoplastics include polymethyl methacrylate, polyethylene terephthalate, polypropylene, polycarbonate, polyimides, and polyvinyl chloride.Such thermoplastic materials can be porous, lightweight, and / or extrudable, and due to the presence of the barrier or coating, they can be used in the structures of the exemplary embodiments. These structures therefore offer the potential to be integrated into films with less expensive substrate materials and / or improved film properties (e.g., lower weight, thinner film) and / or simplified manufacturing processes. This, in turn, can simplify the manufacture of a device incorporating the structures, such as a display device, reduce the display stack size of such a device, and / or, if the carrier particles are light-scattering, eliminate the need to integrate separate light-scattering material into the film or another element of the device.In some embodiments, protective or barrier layers (which reduce the carrier's exposure to oxygen / moisture) are not included in the device (e.g., the film is a so-called barrierless QPVF or xQPVF).

[0074] The film 100 from Fig. In some embodiments, 1 can have a thickness 105 in the range of about 0.03 mm to about 3.0 mm, in the range of about 0.3 mm to about 3.0 mm or in the range of about 0.5 mm to about 1.5 mm, preferably about 1 mm.

[0075] A composition in which structures are located within a liquid support material can be produced by mixing structures with the liquid support.

[0076] In some embodiments, a method for producing a film containing such structures comprises at least one of the following steps: a) Extruding a composition comprising at least one of the following: several of the structures of one of the embodiments described herein or a precursor of the structures, within a liquid support material; b) Pressing a composition comprising at least one of the following: several of the structures of one of the embodiments described herein or a precursor of the structures, within a liquid support material; or c) Forming the film from a composition comprising at least one of the following: several of the structures of the embodiments described herein or a precursor of the structures, within a liquid support material.

[0077] In some such embodiments, the liquid support material can form the solid support material of the film, for example, a molten support material that hardens or a liquid support material that is cured to form a solid. In some embodiments, the liquid support material can be a solvent or other liquid that is removed during the formation of the solid film, and thus the extruded composition can have additional solid support material to carry the structures when the solvent is removed. In some embodiments, the liquid support material can include material that forms the solid support material and material that is removed during the formation of the solid film.

[0078] In some embodiments, the process may include: a) mixing the structures with the support material; and b) extruding or pressing the resulting mixture.

[0079] In some of the embodiments described, the structures are produced before integration into the film. Specific materials are referred to in the following discussion, but the person skilled in the art will understand that other materials, presented as alternatives in the preceding disclosure, may be used instead of those specified below. The arrangement of the components is carried out in a controllable manner by the deposition of QP / zinc thiolate onto alkoxysilanes / light-scattering particles based on evaporation / precipitation ( Fig. 1) The procedure exhibits the following: a) Mixing of colloidal luminescent QP and zinc thiolate in nonpolar organic solvents (e.g., toluene, chloroform) to form a homogeneous QP / zinc thiolate system (mixture I) b) Mixing of alkoxysilanes and light-scattering particles in nonpolar / polar organic solvents to form a heterogeneous system of alkoxysilanes / light-scattering particles (Mixing II) c) Arrangement of several components into hydrophobic spheres by combining Mixture I and Mixture II with subsequent deposition of QP and zinc thiolate onto alkoxysilanes / light-scattering particles by solvent evaporation or controlled diffusion of non-solvent (precipitation).

[0080] In other embodiments, the structures are synthesized during integration into a film containing the structures. In some embodiments, the method has the following features:

[0081] Mixing luminescent nanostructures and one or more coating precursors to form an initial mixture

[0082] Mixing one or more coating precursors, carrier particles and a carrier material into the first mixture to form a second mixture;

[0083] Extrude or press the second mixture to form a film.

[0084] In the following example, reference is made to specific materials, but the person skilled in the art will understand that other materials, presented as alternatives in the preceding disclosure, may be used instead of those specified below. The arrangement of the components is carried out in a controllable manner by the deposition of QP / zinc thiolate onto alkoxysilanes / light-scattering particles based on evaporation / precipitation ( Fig. 1) The procedure exhibits the following: a) Mixing of colloidal luminescent QP and alkoxysilane in nonpolar organic solvents (e.g., toluene, chloroform) to form a homogeneous QP / alkoxysilane system (mixture I) b) Mixing zinc thiolate and thermoplastic material (e.g., polystyrene beads with a diameter < 5 mm) and light-scattering particles in mixture I (mixture II) c) Extruding mixture II to form a film alongside solvent evaporation to form structures according to the embodiments mentioned herein, which are embedded in a thermoplastic film.

[0085] In some embodiments, a method for producing a film containing structures according to the embodiments described herein without a support particle comprises: a) mixing luminescent nanostructures and the material or one or more precursors of the material to form a first mixture; b) mixing a support material and one or more precursors of the material with the first mixture; and c) extruding or pressing the resulting mixture. In some such embodiments, the first mixture may be provided in a solvent that is removed after the extrusion or pressing step.

[0086] Example 1: Example 1 is a control example included for comparison purposes. Red- and green-emitting quantum dots (QPs) were dissolved in a nonpolar organic solvent and combined with thermoplastic polystyrene beads (< 5 mm) and a silicone coating medium (TOSPEARL 120 or ETERPEARL DF10A0). The QP / silicone coating / polystyrene mixture was then compounded in a twin-screw extruder at 200 to 220 °C. After compounding, the mixture was pressed to form a 1.5 mm thick film.

[0087] In Examples 2 to 6, additional additive components were incorporated into the QP / polystyrene film to modify the composition and morphology of the QP's environment and thereby influence the QP's performance retention (service life) under both operating conditions and accelerated stress test conditions. These additives can be added to the QP or the polystyrene, or both, prior to compounding and extrusion, as described below.

[0088] Example 2: The same procedure as described in Example 1 was used. However, a linear alkylalkoxysilane (for example, hexyltrimethoxysilane) was added to the QP stock solution before it was combined with the polystyrene. The silane was added in concentrations of 0.1 to 1.0 wt% based on the mass of the polystyrene.

[0089] Example 3: The same procedure as described in Example 2 was used. However, a metal thiolate (for example, zinc dodecane thiolate) was added to the QP / polystyrene mixture before compounding / extrusion. The metal thiolate was added in concentrations of 0.5 to 5.0 wt% based on the mass of the polystyrene.

[0090] Example 4: The same procedure as described in Example 1 was used. However, a metal thiolate (for example, zinc dodecane thiolate) was added to the QP / polystyrene mixture before compounding / extrusion. The metal thiolate was added in concentrations of 0.5 to 5.0 wt% based on the mass of the polystyrene.

[0091] Example 5: The same procedure as described in Example 4 was used. However, a binder / catalyst (for example, tetrabutylammonium chloride) was added to the QP / polystyrene mixture before compounding / extrusion. The binder / catalyst promotes the bonding of the QP / hydrophobic medium to the surface of the silicone coating medium and was added at a concentration of 0.05 to 1.0 wt% based on the mass of the polystyrene.

[0092] Example 6: The same procedure as described in Example 5 was used. However, a linear alkylalkoxysilane (for example, hexyltrimethoxysilane) was added to the QP stock solution before it was combined with the polystyrene. The silane was added in concentrations of 0.1 to 1.0 wt% based on the mass of the polystyrene.

[0093] Power retention over time under load conditions (6 mW / cm²) 2 (milliwatts per centimeter)2 Excitation flux at 450 nm, 50 °C (Celsius) and 90% relative humidity (RH) is in Fig. 5A for the green emitting QPe and in Fig. 5B shown for the red emitting QPe.

[0094] The power retention in Example 2 is lower than in the control example (Example 1), but the structures of Example 2 reduce the aggregation of the luminescent nanostructures. It is evident that the power retention in Examples 3 to 6 is improved compared to the control example (Example 1). Example 6 offers better performance.

[0095] In Examples 7-9, the procedure from Example 3 was used. However, in Examples 8 and 9, sodium dodecyl sulfate (surfactant) was added to the QP stock solution before it was combined with the polystyrene. Table 1. In this table, ZnDDT = zinc dodecane thiolate; HTMS = hexyl trimethoxysilane; SDS = sodium dodecyl sulfate; wt% based on the mass of polystyrene; BFE - film brightness - fraction of blue photons (wavelength 380-484 nm) absorbed by the film that are emitted as red or green photons (wavelength 484-70 nm), measured as a single-pass measurement by a spectrometer on a QP-containing film under blue light excitation from a diffuse 450 nm LED light source. ZnDDT (wt%) Silicone carrier particles (wt%) HTMS (wt%) SDS (wt. %) BFE (%) Example 7 1.0 1.0 0.3 0.0 49.4 Example 8 1.0 1.0 0.3 0.5 62.4 Example 9 1.0 1.0 0.3 1.0 62.0

[0096] The emission brightness of the resulting film is improved by the addition of the surfactant during the formation of the silanized coordination polymer on the support particles.

[0097] Power retention and emission wavelength stability (PWL) over time under load conditions (6 mW / cm²) 2 Excitation flux at 450 nm, 50 °C and 90% RH) are in Fig. 6A and Fig. 6B for the green emitting QPe and in Fig. 6C and Fig. 6D shown for the red emitting QPe.

[0098] In exemplary embodiments, a device comprises a composition as previously described, for example, a film or multiple structures within a substrate material. Such a device may include a light source configured to emit light of one or more wavelengths absorbed by the nanostructures. In some exemplary embodiments, there is also a filter arrangement comprising red filters for transmitting red light, green filters for transmitting green light, and blue filters for transmitting blue light; and a light valve arrangement. In other such exemplary embodiments, the light source is a light-emitting diode (LED) comprising the composition or film, for example, as a layer (e.g., the top layer) of the LED, configured to receive the light generated by the LED and to emit light from the nanostructures.In this way, each light source can be configured with the composition or film. Another device, in which each light source comprises a corresponding film or composition of the embodiments described herein, is, for example, an arrangement or multiple arrangements of the composition or film, each positioned to receive light emitted by one of the multiple light sources. Such a plurality or arrangement is, for example, provided as a layer separate from the light sources and can be inkjet printed.

[0099] Further details of such a device will now be explained in more detail below.

[0100] In the embodiments described here, compositions are provided comprising (a) a support matrix, (b) several photoluminescent nanostructures dispersed within the support matrix, (c) a secondary antioxidant compound dispersed in the support matrix and configured to decompose one or more hydroperoxides, and (d) an additional base dispersed in the support matrix.

[0101] As a person skilled in the art will recognize, a secondary antioxidant is a compound that reacts, for example, with hydroperoxides to form inactive alcohol products. Examples of secondary antioxidant compounds include trivalent phosphorus compounds, thioethers, and organic sulfides. A reference to the presence of a secondary antioxidant does not imply the presence of a primary antioxidant; the use of the term "secondary" in this context is understood by those skilled in the art to refer to the function of the antioxidant in question.

[0102] Extruded structures containing quantum dots (QPs) have the potential to significantly reduce the cost of using QPs in display applications (compared to cast film systems). However, process conditions during extrusion can be more detrimental and more likely to impair QP performance than conditions used during filmmaking. As such, mitigating extrusion-related damage could potentially improve extruded QP composites to match or exceed the performance of QP laminate film structures.

[0103] Dispersed and / or dissolved in the carrier matrix as a stabilizing additive, the secondary antioxidant compound can consume reactive species generated during extrusion, thus at least partially preventing these reactive species from reacting with the QP and helping to maintain QP performance. In some cases, primary antioxidants (which react with free radicals) have been found to negatively affect QP performance in an extruded composite. Therefore, the compositions in some embodiments do not contain a primary antioxidant.

[0104] In some embodiments, the secondary antioxidant compound contains phosphorus. In some embodiments, the secondary antioxidant compound contains a phosphonate or phosphospiro group.

[0105] In some embodiments, the composition contains 0.01 wt% to 10 wt% of the secondary antioxidant compound on a dry weight basis (e.g., solvents are not present in 100 wt%). In some embodiments, the composition contains up to approximately 1 wt% of the secondary antioxidant compound.

[0106] In some embodiments, the secondary antioxidant compound has the structure A-[(L) n -R] m where A is a structural unit exhibiting secondary antioxidant functionality; each L is a linker group selected from phenyl, -O-, and -S-; n is selected from 0 or 1; each R independently is a C 6-40 -hydrocarbon group that can be substituted; and m is a number from 1 to 6 inclusive.

[0107] In some embodiments, each R can be substituted with one or more halogen or hydroxy substituents. Each R can be linear or branched. Each R can have unsaturated bonds, such as one or two unsaturated bonds. In some embodiments described herein, each R is a linear, saturated alkyl group.

[0108] In some embodiments described herein, A is 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane. In some embodiments, n is 0 and m is 2. In some embodiments, the secondary antioxidant compound is 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (DSPP).

[0109] Without committing this discovery to a specific theory, it is assumed that the R groups can bind to a ligand corona on the surface of the luminescent nanostructures, for example via van der Waals forces. Such binding localizes the secondary antioxidant to the surfaces of the nanostructures and improves the retention of QP performance compared to other antioxidants, as shown in the following examples.

[0110] In some embodiments, the composition may additionally include light-scattering particles formed essentially from a material (for example, entirely within acceptable purity tolerances) for scattering light, e.g., light of a wavelength absorbed by the nanostructures and / or light of a wavelength emitted by the luminescent nanostructures. This light-scattering property increases, for example, the effective path length near the luminescent nanostructures, thereby increasing the coincidence of excitation photons with the nanostructures and improving the downconversion efficiency. In some of these embodiments, the material forming the light-scattering particles has a band gap of more than approximately 3 electron volts (eV). In some embodiments, the light-scattering particles are of an inorganic material.And in some embodiments, the light scattering particles can contain a metal oxide or sulfide, for example one or more of silicon dioxide (SiO2), titanium dioxide (TiO2), zinc oxide (ZnO) or zinc sulfide (ZnS).

[0111] In some embodiments, the composition may additionally include an alkylalkoxysilane and a coordination polymer. An alkylalkoxysilane is an alkoxysilane with a linear or branched alkyl substituent, such as hexyltrimethoxysilane (HTMS). In some cases, the alkylalkoxysilane has a boiling point > 200 °C, such as dodecyltrimethoxysilane or dodecyltriethoxysilane. A coordination polymer may be an inorganic or organometallic polymer structure containing metal cation centers linked by ligands, such as a metal thiolate, for example, zinc dodecane thiolate (ZnDDT). The alkylalkoxysilane and the coordination polymer (e.g., metal thiolate) may form a silanized coordination polymer, which may be water-repellent. The presence of the silanized coordination polymer may thus increase the resistance to water-initiated degradation of the nanostructure performance.

[0112] A judicious selection of alkylalkoxysilanes offers practical as well as performance advantages. Some alkylalkoxysilanes are more volatile than others (for example, hexyltrimethoxysilane has a boiling point of ~200 °C, while the two additional compounds listed above have higher boiling points: dodecyltrimethoxysilane, sp ~280 °C; dodecyltriethoxysilane, sp ~330 °C). Since the compounding and extrusion of thermoplastic QP sheets in polystyrene takes place at ~220 °C, a less volatile silane can offer advantages in terms of (1) yield and effectiveness, as it is more likely to remain within the thermoplastic QP sheet, and (2) reduced evaporation into the local atmosphere.

[0113] In some embodiments, the composition comprises a silanized coordination polymer, which is the reaction product of an alkylalkoxysilane and a coordination polymer (for example, a metal thiolate), and in some embodiments, a silanized coordination polymer, which is the reaction product of a linear alkylalkoxysilane and a metal thiolate. In some embodiments, the silanized coordination polymer can be formed from an alkylalkoxysilane and a metal thiolate with a weight ratio of alkylalkoxysilane to metal thiolate of approximately 1:5. In some embodiments, the silanized coordination polymer can be formed from hexyltrimethoxysilane and zinc dodecane thiolate.

[0114] In some embodiments, the silanized coordination polymer can be the reaction product of an alkylalkoxysilane and a metal thiolate in the presence of a surfactant. In some such embodiments, the surfactant can be an anionic surfactant containing a sulfate, sulfonate, phosphate, and / or carboxylate group. In some specific embodiments, the anionic surfactant can be an alkyl sulfate, such as ammonium dodecyl sulfate and sodium dodecyl sulfate, or an alkyl ether sulfate, such as sodium laureth sulfate or sodium myreth sulfate. In some specific embodiments, the anionic surfactant can be sodium dodecyl sulfate. In some specific embodiments, the anionic surfactant can be a metal carboxylate. In some specific embodiments, the metal carboxylates can comprise a lithium salt of a fatty acid.Non-restrictive examples of lithium salts of fatty acids include lithium stearate, lithium oleate, and lithium palmitate. The presence of a surfactant during the reaction of an alkylalkoxysilane with a metal thiolate can, in some embodiments, improve the emission brightness, emission power conservation, and / or the stability of the emission wavelength over time.

[0115] In some embodiments, the composition may additionally include a hindered amine light stabilizer (HALS) as a stabilizing additive. As those skilled in the art will understand, hindered amine light stabilizers are, for example, compounds that can be mixed into polymers (including plastics) and contain an amine functional group. The amine group is, for example, hindered to reduce or minimize side reactions or conversion of the HALS to nitrone species; for example, in some cases, the hindered amine may lack alpha hydrogens to reduce or minimize conversion to a nitrone. A HALS can at least partially prevent photooxidation and possibly other forms of polymer degradation, such as ozonolysis.HALS generally do not absorb ultraviolet (UV) radiation, but function by inhibiting polymer degradation through the continuous and cyclical removal of free radicals generated by photooxidation of the polymer. The overall process is sometimes referred to as the Denisov cycle. In general, a HALS can react with the initial polymer peroxy radical (ROO·) or alkyl polymer radicals (R·) formed by the polymer's reaction with oxygen, at least partially preventing further radical oxidation. Through these reactions, HALS are oxidized to their corresponding aminoxyl radicals, but revert to their initial amine form via a series of additional radical reactions.

[0116] In some embodiments, a HALS may contain 2,2,6,6-tetramethylpiperidin-4-yl: Fig.Figure 7A shows the molecular structure of 2,2,6,6-tetramethylpiperidin-4-yl, a hindered amine light stabilizer, with the asterisk indicating the attachment point to the rest of the compound structure. It is noted that a HALS containing piperidine structural units may be resistant to intramolecular polymerase reactions.

[0117] Furthermore, it is observed that the two new HALS compounds disclosed herein can offer an improvement over the existing HALS compound—both individually and in combination with the existing compound. By conclusion, one HALS compound may be superior to another in a given formulation due to (1) thermal stability, (2) synergism with other formulation components, (3) resistance to deactivation by acids or other chemical antagonists, or (4) dispersion and migration within the thermoplastic article. Several related HALS compounds can be used in combination to provide the improved stabilization due to complementary pathways to oxidant deactivation.

[0118] In some embodiments, the HALS has a polymer backbone, and the 2,2,6,6-tetramethylpiperidin-4-yl is, for example, bound to the polymer backbone within the repeating unit of the polymer. In some such embodiments, the HALS may comprise poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]]), which in some specific embodiments may have a molecular weight in the range of about 2000 to 3100 grams per mole (g / mol). In some such embodiments, the HALS 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)polymer with 2,4,6-trichloro-1,3,5-triazine may contain reaction products with N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, which in some specific embodiments may have a molecular weight in the range of 2600 and 3400 grams per mole (g / mol).In some such embodiments, HALS may comprise poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanedioic acid), which in some specific embodiments may have a molecular weight in the range of 3100 and 4000 grams per mole (g / mol).

[0119] In some embodiments, the luminescent nanostructures are quantum dots.

[0120] The secondary antioxidant compound and the luminescent nanostructures are dispersed in a support matrix—that is, a “carrier.” In some embodiments, the carrier comprises a thermoplastic material or a thermoplastic precursor. In some cases, the carrier material comprises polystyrene.

[0121] In some embodiments, the support comprises a liquid, such as a solvent. In such cases, the composition behaves like a liquid (e.g., a liquid or a suspension of solid particles in a liquid). The liquid support can be at least partially removed from the composition before or during extrusion. In some embodiments, the support may contain heptane.

[0122] In some embodiments, a solid structure is provided having the composition described herein. The structure may be formed by a process that includes an extrusion step. In some cases, the structure is completely or substantially planar and may be described as a plate, a layer, a film, or the like. In some embodiments, "substantially planar" means that the thickness of the structure is less than approximately 5% of its width and length, such as less than approximately 1%. In some embodiments, "substantially planar" means that the thickness of the structure is entirely within approximately 10% of its mean thickness, such as within ±5%. The planar structure may have a thickness ranging from about 0.03 millimeters (mm) to about 3.0 mm.

[0123] According to some embodiments, the composition herein may be provided as a solid, substantially planar structure, which could alternatively be described as a plate, film, layer, or the like. In some embodiments, this may be formulated by mixing components of the composition alongside a liquid support (such as a solvent), drying to remove the solvent, and extruding the composition. Some embodiments may include the subsequent steps of heating to dry the extruded composition (e.g., solvent removal) and / or hardening components of the composition by exposure to light or heating.

[0124] In some embodiments, a separate barrier film (for example, in a so-called quantum dot enhancement film (QPVF)) does not need to be applied, as the nanostructures are protected from moisture and / or air by the secondary antioxidant compound and / or the additional base.

[0125] Exemplary embodiments are now described with reference to the figures and the comparative examples described herein. In the following exemplary embodiments and comparative examples, the following dry powders were mixed: polystyrene, SiO₂ particles (light-scattering particles), zinc dodecane thiolate, hexyl trimethoxysilane, Chimassorb® 944 (a BASF product of Ludwigshafen, Germany), and an antioxidant compound, if present. Quantum dots suspended in heptane were then added to the powder mixture, and the solvent was allowed to evaporate. The resulting mixture was extruded to form plates, which were then subjected to testing.

[0126] Chimassorb®944 is a HALS which is poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]]). <Vergleichsbeispiel 1>This comparison example did not contain any antioxidants.<Beispiel 1> In this example, 0.5 wt% DSPP was added to the powder mixture.

[0127] The backlight film efficiency (BFE) for the plate of Example 1 was 62.1%, while the BFE for the plate of Comparison Example 1 was 57.5%. It is noted that BFE is a measure of brightness and is the proportion of blue photons (wavelength 380 to 484 nm) absorbed by the plate that are emitted as red or green photons (wavelength 484 to 780 nm), measured as a single-pass measurement by a spectrometer on a QP-containing plate under excitation with blue light from a diffuse 450 nm LED light source.

[0128] <Vergleichsbeispiele 2A-D> These comparative tests included a number of primary antioxidants in the extruded composition. Fig.Figure 8 shows the green QP power retention for comparison examples 2A-D and for example 1. It is evident that the power retention with the addition of DSPP is lower compared to the primary antioxidants under test conditions (flux 6 mW / cm²). 2 at 50 °C and 90% relative humidity) was significantly improved.

[0129] Fig. Figure 8 illustrates the effect of adding DSPP to the compositions of the comparison examples. Each was prepared as described above. Table 2. Performance data for luminescent nanostructures within compositions of examples and comparison examples. formulation HTMS (wt. %) ZnDDT (wt%) Chimass orb944 (wt.%) DSPP (wt%) BFE (%) Green emission wavelength (nm) Green width at half maximum (FWHM) (nm) Red emission wavelength (nm) Red width at half maximum (FWHM)(nm) ZnDDT+ Silane 0.33 1.0 - - 51.9 538.1 21.4 626.8 26.1 THROAT+ Silane 0.33 - 0.80 - 55.8 538.9 21.5 629.9 26.4 ZnDDT + Silane + Throat 0.33 1.0 0.80 - 60.3 538.4 21.5 627.6 25.3 ZnDDT+ Silane+ 0.33 1.0 0.80 0.50 62.1 538.3 21.4 627.5 25.7 THROT+ DSPP

[0130] Table 2 and Fig. 9A, Fig. 9B, Fig. 10A and Fig. Section 10B provides details of other formulations that operate at a flux of 6 mW / cm². 2The fourth composition was tested at 50°C and 90% relative humidity. It exhibits higher backlight film efficiency than the other compositions.

[0131] Fig. 9A and Fig. Figure 3B illustrates that the fourth composition from Table 2 exhibits better green QP performance retention and significant red QP performance retention.

[0132] Fig. 10A and Fig. Figure 10B illustrates that the fourth composition from Table 2 exhibits significant emission wavelength stability for both green emitting QPe ( Fig. 4A) as well as for red emitting QPe ( Fig. 4B).

[0133] Quantum dot-in-polymer nanocomposites (e.g., barrierless QPVF, QD thermoplastic sheets, etc.) represent a novel class of bright, narrow-emitting materials for display applications. To enhance the stability of the QP properties in these composites against photooxidation, complex additive combinations with diverse functions (chain-breaking antioxidants, peroxide decomposers, photostables, etc.) are being developed to improve the lifetime of QP photoluminescence. This disclosure reports a further improvement in QP performance through next-generation additive compositions that stabilize QPe within the polymer matrix and provide long-term protection. Specifically disclosed herein is a new class of co-additives that exhibits synergistic behavior in multi-component mixtures and enables a further improvement in the service life of QPe within polymer matrices.These additives significantly reduce oxidation-induced deterioration rates under photoexcitation in humid conditions.

[0134] The photooxidation of light-emitting semiconductor QPs, which can be catalyzed by water molecules and / or metal ions and accelerated by heat, generally leads to reactive species (e.g., peroxides and hydroxy and (alkyl)peroxy radicals). These highly reactive species photocorrode the inorganic units of the emitting material, reduce the photoluminescence quantum yields, and limit the service life of optical QP components (QPEFs, QP thermoplastic diffuser plates, etc.).

[0135] To address the problem of QP operational stability for barrierless QPVF and QP thermoplastic optical plates, protective agents (antioxidants) can be used. These agents inhibit photooxidation-induced deterioration of QP. Due to the complex nature of QP photooxidation, mono- and / or bifunctional antioxidants may not provide sufficient protection against photooxidative deterioration. The rational combination of various antioxidants with complementary functions, such as chain-breaking antioxidants, peroxide decomposers, photostablers, and / or metal deactivators, appears to be a powerful approach that could significantly improve QP performance.

[0136] Formulating efficient multi-additive mixtures of functional antioxidants with synergistic behavior that protect qp from photooxidation is desirable to address the problem of qp operational stability for barrierless qPEF and qp thermoplastic optical plates. This can enable cost-effective solutions for bright and narrow emitters in optical components and can increase the market share of qp in electronic displays.

[0137] The antiphotooxidative QP efficiency of a multi-additive mixture of antioxidants, which includes preventive antioxidants such as phosphorus-containing antioxidants (e.g., 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane), sulfur-containing antioxidants (e.g., zinc dodecane thiolate), and photostables such as hindered amine stabilizers (e.g., N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexane-1,6-diamine; 2,4,6-trichloro-1,3,5-triazine; 2,4,4-trimethylpentan-2-amine), can be significantly improved by the addition of a basic additive such as 2,4,6-triamino-1,3,5-triazine (melamine). This exemplary compound appears to demonstrate a synergism for all components of the multifunctional antioxidants. Fig. Figure 7B shows the structure of melamine, which can be used as an additional base. Fig.Figure 7C shows the structure of an exemplary substituted melamine, which can also be used as an additional base. In the illustrated structure, each R can comprise a hydrogen atom or an alkyl or aryl group. The R groups may be equivalent in some examples and different in others. Any, some, or all of the R groups can be selected to improve the dispersibility of the secondary amine compound in the support matrix.

[0138] Melamine can act as a basic protection of antioxidant compounds and / or QP against in situ generated acids, which can otherwise deactivate the stabilizing functions of hindered amine stabilizers (e.g., via the deactivation of a piperidinyl structural unit) or of phosphorus- and / or sulfur-containing antioxidant compounds (via the catalytic hydrolysis of phosphites or sulfides), or which can trigger the etching of light-emitting semiconductor QP with subsequent deterioration of the optical properties.

[0139] Additionally, melamine is a powerful heat stabilizer that increases the resistance of both QP and antioxidant compounds to thermal deterioration, which can be a serious problem during QP composite processing (e.g., high-temperature extrusion, forming, spinning, calendering, coating) and in-service applications (e.g., barrier-free QPEF or QP thermoplastic sheets in displays where temperatures near the blue light source (LED or mini-LED) can approach and exceed 50°C).

[0140] The combination of the above properties of melamine improves the antioxidant behavior of the multi-additive mixture and enables a significant reduction in the oxidation-induced deterioration rate under photoexcitation in humid conditions.

[0141] Fig.Figure 11 shows aspects of reliability data (performance versus time) for green and red emitting QPs under various test conditions. The multi-additive mixture contains 1.5 wt% N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexane-1,6-diamine; 2,4,6-trichloro-1,3,5-triazine; 2,4,4-trimethylpentan-2-amine; 1.5 wt% zinc dodecane thiolate; 0.5 wt% 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane; 0.2 wt% hexyltrimethoxysilane; with and without 0.65 wt% melamine. The conditions in the first series of Fig. 11 equals 16 mW / cm² 2 , 60 °C and 90% relative humidity. The conditions in the second row are 6 mW / cm². 2 , 50 °C and 90% relative humidity. The conditions in the third row are 50 mW / cm². 2 and 50 °C at ambient humidity.

[0142] The antioxidant mixtures contained herein include at least one additional base. Each additional base can be a Brønsted base or a Lewis base. In some examples, the Brønsted base can be a metal carbonate. In certain specific examples, the Brønsted base can be a lithium carbonate.

[0143] The additional base can be an aromatic or aliphatic amine, which may be saturated, unsaturated, bridged, cyclic, or open-chain, straight or branched, with or without rings of any kind. The amines can be primary, secondary, or tertiary. The amines can be polymeric, oligomeric, monomeric, or low-molecular-weight. In some examples, the additional base may be a Mannich compound—that is, a product of a Mannich condensation.

[0144] The additional base can be thermally stable, with nitrogen-containing heterocycles and with (one) amine-based functional group(s).

[0145] The additional base can be a triazine or triazine derivative (including a triazine isomer) containing one or more amine-based functional groups. In some embodiments, the additional base can be an aromatic imine base.

[0146] The additional base may contain melamine (2,4,6-triamino-1,3,5-triazine) or a melamine derivative. Table 3. Amount of antioxidants in polystyrene / QP substrates and their corresponding optical properties. Formulation HTMS (wt. %) ZnDDT (wt%) Chimass orb944 (Wt.- %) DSSP (Wt. %) Melamine (wt%) BFE (%) Green emission λ(nm) Green width at half maximum (FWHM)(nm) Red emission λ(nm) Red width at half maximum (FWHM)(nm) with melamine 0.2 1.5 1.5 0.5 0.65 61.5 539.9 24.2 617.3 23.7 melamine-free 0.2 1.5 1.5 0.5 - 61.4 540.3 24.3 617.1 23.8

[0147] In some embodiments, a composition according to the present disclosure can have several heterogeneous domains distributed within the support matrix. The average size of a heterogeneous domain is not particularly limited, but can range, for example, from several tens of nanometers to several tens of micrometers. In compositions having heterogeneous domains, at least one of the photoluminescent nanostructures and at least one of the stabilizing additives can together be distributed as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives. Exemplary stabilizing additives include one or more hindered amine stabilizer(s), one or more alkylalkoxysilane(s) and coordination polymer(s), one or more silanized coordination polymer(s), and one or more secondary antioxidant(s).All sub-combinations among these variants are considered. In this way, the photoluminescent nanostructures can be arranged in contact with any, some, or all of the means that stabilize their emission performance.

[0148] In some embodiments, a device comprises a composition as previously described, for example, a planar structure (such as a plate, film, or layer) formed from the composition. Such a device may include a light source configured to emit light of one or more wavelengths absorbed by the nanostructures. In some embodiments, there is also a filter arrangement comprising red filters for transmitting red light, green filters for transmitting green light, and blue filters for transmitting blue light; and a light valve arrangement.In other such embodiments, the light source is a light-emitting diode (LED) comprising the composition or film, for example, as a layer (e.g., the top layer) of the LED, arranged to receive the light generated by the LED and to emit light from the nanostructures. Each light source can be configured with the composition or film in this way. Another device, in which each light source comprises a corresponding film or composition, is, for example, an array or multiple arrays of the composition or film, each positioned to receive light emitted by one of the multiple light sources. Such an array or array is, for example, provided as a layer separate from the light sources and can be inkjet printed.Further details of such a device will now be described in more detail below.

[0149] A device within the scope of the disclosure is now referred to Fig. 12A and Fig. 12B described. The in Fig. 5A and Fig.The device shown schematically in Figure 5B is a display device 402 comprising functional elements configured to work together to generate and output an image. Several such functional elements are stacked and collectively referred to as a display stack 404. The display stack 404 includes, for example, a light source 410 configured to emit light 407 (for example, a light-emitting diode (LED) or organic LED (OLED) backlight), a light valve arrangement 414 (for example, a liquid crystal display (LCD) panel) for modulating the amount of light received from the light source, and a filter arrangement 416 (for example, a color filter arrangement such as a red, green, and blue subpixel filter arrangement) for determining the color of the light output by the display device 402 (for example, through each subpixel region of the device).A plate 400 according to exemplary embodiments can be arranged between the light source 410 and the light valve arrangement 414 (as in . Fig. 6A), or can be arranged between the light valve assembly 414 and the filter assembly 416 (as shown, for example, in Fig. 6B (shown).

[0150] The display device 402 has a light source 410 positioned to provide, for example, a backlit or edge-lit display. The light source is, for example, at least one of: an LED, an LED array, an organic LED (OLED), an OLED array, a laser, a laser array, or a lamp. The light source may be configured to illuminate multiple image elements of the display device, or there may be a plurality of light sources, each illuminating a single image element. An image element is, for example, a subpixel or pixel of a display device. A display device typically has a plurality of image elements that are independently controllable so that the display device displays an image. The image elements are arranged according to a pattern, for example, as an array, matrix, or grid, as understood by those skilled in the art.A display device capable of showing a color image typically has a multitude of pixels, each pixel having a multitude of subpixels; for example, a pixel has a red (R) subpixel, a green (G) subpixel, and a blue (B) subpixel, which together function as an RGB pixel. There may be additional, independently controllable subpixels, such as a white (W) subpixel, to create an RGBW pixel.

[0151] In addition to such a light source, a display device includes a light modulator configured to modulate light emitted by the light source to display an image. The light modulator comprises an array of light modulator regions for modulating light. Each light modulator region of the array corresponds to a specific image element of the display device. For example, when a viewing side of the display device is viewed to show an image to a user's eye, one extent of a light modulator region defines one extent of an image element. The light source or light guide has an extent covered by the array of light modulator regions so that each light modulator region can be illuminated by the light source. The previously described light valve arrangement 414 is an example of such a light modulator.

[0152] A display device control system (not shown) is configured to control the arrangement of light modulator areas so that the display device outputs an image. Each light modulator area can be controlled independently to modulate the amount of light transmitted through the modulator area to the viewing side for each image element. Thus, one light modulator area can be switched to transmit less light (a darker state) than another light modulator area (a brighter state), so that with suitable light modulation via the arrangement of light modulator areas (and thus the image elements), the display device can show a desired image.

[0153] As a person skilled in the art understands, a type of light modulator uses liquid crystal (LC) molecules to modulate light. By applying an electric field of suitable magnitude to the electrodes of a light modulator region, the orientation of the LC molecules can be changed to modulate the light emitted by a particular image element to display an image on a viewing screen. An LC light modulator has a polarizer layer to linearly polarize the light input to the light modulator. The polarizing layer is located on a substrate (for example, glass). There is a circuit layer on the substrate connected to an array of electrodes (for example, made of indium tin oxide (ITO)), each of which is electrically isolated from the others and has an extent that determines the shape and size of each image element.The electrodes contain a layer comprising LC molecules, the LC molecules and their density within the layer being selected to provide the required rotation of linearly polarized light according to a given magnitude of the applied electric field. An alignment layer is in contact with the LC molecule layer to align the LC molecules in contact with the alignment layer in a specific orientation. There is another linear polarizer layer for polarizing light exiting the light modulator, oriented to linearly polarize light in a specific orientation, for example, perpendicular to the polarizer layer described above. A substrate (for example, glass) is located on top of this other linear polarizer layer. There is an electrode with an extent sufficient to cover more than one (for example, all) image elements, which can be referred to as a common electrode.

[0154] In these embodiments, each pixel also includes a color filter between the alignment layer and another linear polarizer layer. By appropriately selecting the color filter for each pixel, an RGB pixel (of three subpixel pixels) can be fabricated with red filters for transmitting red light, for example, with a wavelength of 630 nanometers, green filters for transmitting green light, for example, with a wavelength of 532 nanometers, and blue filters for transmitting blue light, for example, with a wavelength of 467 nanometers. An arrangement of such color filters is an example of the filter arrangement described above.

[0155] The display device comprises a display stack of functional elements, including, for example, the light source, the QPVF, and the filter array. In these embodiments, the light modulator is also present, and starting from the bottommost layer of the stack, there is a substrate (for example, made of glass), a light source circuit layer on the substrate, and a plurality of LEDs as the light source connected to the circuit layer. In a backlit embodiment, the plurality of LEDs are configured and positioned to illuminate the light modulator, for example, as an array of LEDs overlapping the light modulator.

[0156] The density and positioning of the LEDs depend at least partially on the shape and size of the display's pixels, but also on the illumination characteristics of each LED and any layers, such as a diffuser or reflector for transferring light from the LEDs to the light modulator. In some such embodiments, each LED in the multiple LEDs of the illumination device is configured to illuminate a multiple of pixels (for example, 50 to 100 or several thousand) of the display. Each multiple of pixels can be considered a zone with a so-called mini-LED configuration, with each zone being independently controllable in some embodiments compared to other zones. Switching different zones on and off can improve contrast, for example, by switching off one zone to obtain a deeper black, and can be referred to as "local dimming."

[0157] In other embodiments that are edge-illuminated, instead of an arrangement of LEDs, there is a light guide that is overlapped by the light modulator, and at least one LED of the plurality of LEDs is positioned along at least a portion of a circumference of the light guide to illuminate the light modulator via the light guide. In some such embodiments or other embodiments, there is a light diffuser that is overlapped by the light modulator.

[0158] Between the LEDs and the light modulator, one or more layers may be located, for example, a diffuser to distribute light from the LEDs more evenly across the light modulator, and / or an alignment layer (for example, a so-called brightness enhancer film (BEF), which uses prisms to align light from the LEDs with each image element). Multiple diffuser and / or alignment layers of this type may be used in some embodiments. As those skilled in the art will recognize, various other functional elements may be used, for example, to modify light.Examples include a so-called “Dual-BEF” (DBEF) to polarize light for a liquid crystal light valve assembly and to reflect light that does not have the desired polarization for the liquid crystal light valve assembly to the backlight for reflection towards the DBEF, a thin-film encapsulation (TFE) layer, a prismatic layer, a reflector, a partial reflector, a polarizer, a diffuser, a barrier layer, an antireflection layer, or a collimator.

[0159] The circuit layers for the light source and the light modulator are each connected to the display device control system and are configured to control the light source and light modulator via the display device control system to output a desired image. The light modulator circuit layer, for example, is configured for so-called active matrix control of the light modulator areas by using one switching element (e.g., a thin-film transistor (TFT)) per pixel and applying appropriate electrical signals to the source and gate terminals of each TFT to adjust each light modulator area to transmit a desired amount of light. The light source circuit layer is configured to control the light output from the LEDs, for example, to turn on a specific zone of LEDs while keeping other zones off.Depending on the number of LEDs and their layout, the circuit layer of the light source may even include switching elements (e.g., TFTs) for active matrix control of the LEDs.

[0160] The display device control system is connected to the circuit layers and the common electrode via signal lines. The display device control system includes, for example, a data input for receiving data representative of one or more images so that the display device can display them. As a person skilled in the art will recognize, the display device control system comprises a circuit for determining and applying (and, based on data representative of an image to be displayed) suitable electrical signals to the electrodes of the light modulator and the LEDs of the light source.

[0161] As a person skilled in the art will recognize, the magnitude of the voltage applied between the common electrode and the electrode of a light modulator region of a given image element, and therefore the magnitude of the applied electric field, determines a rotational alignment of the LC molecules by the image element relative to the orientation determined by the alignment layer and also relative to the linear polarizer layers. Thus, the extent of the light modulation of each light modulator region can be controlled, and in turn, the amount of transmitted light can be controlled, which is either aligned with the alignment layer or at least partially rotated in its orientation relative to the alignment layer.

[0162] As the person skilled in the art will recognize, other types of examples are considered which feature a light modulator in combination with a light source, but which use a technology (for example, microelectromechanical (MEMs) or electrophoretic technology) that differs from LC technology for light modulation.

[0163] Further embodiments are considered in which LEDs of the light source each correspond to a specific image element and are controllable to modulate the light output through each image element, instead of using a separate light modulator in combination with the illumination device. For example, each subpixel can have a blue LED, and a plurality of subpixels can be illuminated by a white LED or, alternatively, by a green and a red LED. By appropriately controlling each blue LED and the green and red LEDs, a color of an image output by the display device can be set.

[0164] A display device as described herein may be, for example, a display panel, display unit or display screen for a device such as a television, computer monitor, tablet computing device, laptop computing device, mobile telecommunications device such as a smartphone, a portable (e.g. mobile) device, an electronic reading device, a clock, a satellite navigation device, a head-up display device, a gaming console, a flexible display, an augmented reality (XR) device, a virtual reality (VR) device and / or an augmented reality (AR) device.

[0165] The display device can, for example, be integrated into a device comprising: the display device, at least one processor; and at least one memory containing computer program instructions, wherein the at least one memory and the computer program contain instructions configured to control the display device control system with the at least one processor in order to control the display device to output an image.

[0166] A system diagram illustrating an example of a basic hardware architecture of the System 650 is shown in Fig. Figure 13 shows an electronic device, such as a laptop computer. It should be noted that in other implementations some of the features shown in Figure 13 are not shown. Fig.The components shown in Figure 13 are not present; for example, for a computer monitor implementation, the system memory and / or the battery may be absent. System 650 comprises: the display device 654; at least one processor 658, which is connected, for example, to a display device control system 652 (for example, according to previously described embodiments), a communication system 656, a user input system 660, a power system 662, and a system memory 664, and is therefore in data communication with them. The display device control system is connected to the display device 654 and is therefore in data communication with it.

[0167] The display device control system 652, for example, includes driver components for use when applying a voltage to one of the image elements in order to address different such image elements. In exemplary embodiments, the light modulator areas of the image elements are driven using an active matrix control scheme, and the display device control system is configured to control switching elements, such as thin-film transistors (TFTs) of the display device 654, via a circuit to control the image elements. The circuit may include signal and control lines. For example, the display device control system 652 may include display drivers, such as display column drivers and display row drivers.

[0168] The at least one Processor 658 is, for example: a general-purpose processor; a microprocessor; a digital signal processor (DSP); an application-specific integrated circuit (ASIC); a field-programmable gate array (FPGA); a programmable logic device; discrete gate or transistor logic; discrete hardware components; or any suitable combination thereof that can be configured for the functions described herein. A processor may be a combination of computing devices, such as: a DSP and a microprocessor; multiple microprocessors; a microprocessor in conjunction with a DSP core; or any other such configuration. The Processor 658 may be coupled via one or more buses to read or write information from a memory. The Processor 658 may additionally or alternatively include a memory, such as a processor register.

[0169] The Communication System 656, for example, is configured for the System 650 to communicate with a computing device over a data network; a computer network, such as the Internet; a local area network (LAN); a wide area network (WAN); a telecommunications network, a wired network, a wireless network, or another type of network. The Communication System may include: an input / output (I / O) interface, such as a Universal Serial Bus (USB) connection, a Bluetooth connection, or an infrared connection; or a data network interface for connecting the device to a data network, such as one described above. Content data, as described later, may be transmitted to the System via the Communication System.

[0170] The user input system 660 can have an input device for receiving input from a user of the system.Examples of input devices include, but are not limited to, a keyboard, a rollerball, buttons, keys, switches, a pointing device, a mouse, a joystick, a remote control, an infrared detector, a speech recognition system, a barcode reader, a scanner, a video camera (possibly coupled with video processing software to detect, for example, hand or facial gestures), a motion detector, a microphone (possibly coupled with audio processing software to detect, for example, voice commands), a VR glove, an AR glove, a haptic input device, a computer vision device, a simultaneous localization and mapping (SLAM) device, an eye tracking device, a hand tracking device, or any other device capable of transmitting information from a user to the device.The input device can also take the form of a touchscreen associated with the display device 654, in which case a user responds to prompts on the display device 654 by touching it. The user can enter text information through the input device, such as the keyboard or the touchscreen.

[0171] The system may also include a user output system (not shown), which may include, for example, an output device for providing output to a user of the system. Examples include, but are not limited to, a printing device, an audio output device (such as one or more speakers, headphones, earphones, alarms, or haptic output devices), and a connector port for connecting to any of the other described output devices, such as headphones.

[0172] The 662 power system, for example, features a power circuit for transferring and controlling the power consumed by the system. The power can be supplied by a mains power supply or by a battery (not shown) via the power circuit. The power circuit can also be used to charge the battery from a mains power supply.

[0173] Memory 664 includes memory, for example, at least one volatile memory 666 and one non-volatile memory 670, and may include a non-volatile, computer-readable storage medium. The volatile memory may be, for example, random-access memory (RAM). The non-volatile (NV) memory may be, for example, a solid-state drive (SSD), such as flash memory, or read-only memory (ROM). Other storage technologies may be used, such as magnetic, optical, or tape media, compact disc (CD), digital versatile disc (DVD), Blu-ray, or other data storage media. The volatile and / or non-volatile memory may be removable or non-removable.

[0174] Each of the memory locations can store data for controlling the system. Such data can be in the form of computer-readable and / or executable instructions, such as computer program instructions. Therefore, the at least one memory location and the computer program instructions can be configured to control the display device control system for outputting an image on the display device 654, together with the at least one processor.

[0175] In the example of Fig.For example, the volatile memory 666 stores display device data 668, which displays an image to be provided by the system. The processor 658 can transfer data based on the display device data 668 to the control system 652, which in turn outputs signals to the display device to apply voltages to the image elements in order to display an image 675. The non-volatile memory 670 stores, for example, program data 672 and / or content data 674. The program data is, for example, data that represents computer-executable instructions, such as in the form of computer software, so that the system can execute applications or program modules for the system or components or systems of the system to perform certain functions or tasks, and / or to control components or systems of the system. For example, application or program module data includes routines, programs, objects, components, data structures, or the like.Content data is, for example, data that represents content, such as for a user; such content can represent any form of media, such as text, at least one image or part thereof, at least one video or part thereof, at least one sound or music, or part thereof. Data that represents an image or part thereof is, for example, representative of an image to be provided by at least one image element of the display device. Such data may comprise content data of one type, or it may instead comprise a mixture of content data of different types; for example, a film can be represented by data that includes at least image data and sound data.

[0176] The term "approximately" indicates that a numerical value can be approximate. This may be due to acceptable functional and / or measurement tolerances. For example, an approximation allows ±5% of the stated numerical value.

[0177] The term nanostructure, as used herein, refers, for example, to a structure with at least one region or characteristic dimension measuring less than approximately 500 nm. In some embodiments, the nanostructure has a dimension of less than approximately 200 nm, less than approximately 100 nm, less than approximately 50 nm, less than approximately 20 nm, or less than approximately 10 nm. Typically, the region or characteristic dimension will be along the smallest axis of the structure. Examples of such nanostructures include nanowires, nanorods, nanotubes, branched nanostructures, nanodots, quantum dots (QPs), nanoparticles, and the like.In some embodiments, each of the three orthogonal dimensions of the nanostructure has a dimension of less than approximately 500 nm, less than approximately 200 nm, less than approximately 100 nm, less than approximately 50 nm, less than approximately 20 nm, or less than approximately 10 nm.

[0178] The term “quantum dot” or “QP,” as used herein, refers, for example, to nanostructures that are essentially monocrystalline (e.g., having a single crystal). For example, a QP may have a core-shell structure; the core is essentially monocrystalline and may have one or more shells on it. A QP, for example, has at least one region or characteristic dimension with a size of less than approximately 500 nm and down to the order of less than approximately 1 nm. In some embodiments, the QP have a maximum size of between approximately 2 nm and approximately 30 nm. Quantum dots described herein can be viewed as fluorescent semiconductor structures, each having a semiconductor crystallite with a diameter of less than or equal to twice the Bohr radius of an exciton inducible in the semiconductor crystallite.Such a radius leads to quantum confinement of the exciton when it is induced into the semiconductor crystallite. The Bohr radius depends on the elemental composition of the semiconductor crystallite. For example, the Bohr radius of cadmium selenide (CdSe) is 5.4 nanometers, so a quasispherical CdSe semiconductor crystallite is a quantum dot if its radius is less than 5.4 nanometers. Other embodiments include: zinc selenide telluride (ZnSeTe) crystallites with a diameter between 4 and 5 nanometers, which are blue-light-emitting quantum dots; indium phosphide (InP) crystallites with a diameter between 2 and 2.5 nanometers, which are green-light-emitting quantum dots; and InP crystallites with a diameter between 2.8 and 3.5 nanometers, which are red-light-emitting quantum dots. The quantum confinement of excitons leads to fluorescence.Quantum confinement can be induced in three dimensions, two dimensions (a quantum wire), or one dimension (a quantum well). Other morphologies of the semiconductor crystallite are being considered, such as cuboids or tetrahedra. The quantum dots can contain at least one of the following alloys: a III-V semiconductor, a II-VI semiconductor, zinc telluride selenide (ZnTeSe), zinc telluride (ZnTe), zinc selenide (ZnSe), zinc sulfide (ZnS), indium phosphide (InP), indium gallium phosphide (InGaP), indium arsenide (InAs), indium zinc phosphide (InZnP), indium arsenide (InAs), indium arsenide phosphide (InAsP), indium gallium arsenide phosphide (InGaAsP), silver indium gallium sulfide (AgInGaS or AIGS), copper indium sulfide (CuInS or CIS), copper indium gallium selenide (CuInGaSe or CIGS), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium telluride (CdTe), cadmium selenide telluride (CdSeTe), cadmium zinc selenide (CdZnSe), molybdenum disulfide (MoS₂) or an alloy thereof. The ratio orThe ratios between the elements of the alloys are not specified, and various ratios are considered, as a person skilled in the art will recognize. The quantum dots can each have a core-shell structure with at least one shell on a core, the diameter of which is twice the Bohr radius or smaller. The shell is, for example, a metal sulfide and / or a metal oxide. Exemplary core-shell structures can be formed from CdSe(core) / CdS / ZnS or InP(core) / ZnSe / ZnS. The quantum dots can be functionalized with at least one ligand, for example, a polyethylene glycol, a polythiol, and / or a carboxylate. Shell and / or ligand functionalization can improve the properties of the quantum dots, such as quantum yield, thermal stability, and / or photostability.The quantum dots can be encapsulated, for example to reduce their toxicity. Many encapsulating agents are considered, such as a silane or a metal oxide, as those skilled in the art will recognize.

[0179] The term "maximum dimension" in relation to a structure refers, for example, to the largest measurable straight-line distance of that structure in every direction. For instance, in the context of a spherical structure, the maximum dimension is its diameter.

[0180] The term "thickness" in relation to a film, coating, layer, or the like refers, for example, to the depth of that film, coating, or layer. If the film or layer is planar, for instance, the thickness refers to the distance measured orthogonally to that plane.

[0181] The above embodiments are to be understood as illustrative examples. It is understood that each feature described in relation to any given embodiment can be used alone or in combination with other described features, and can also be used in combination with one or more features of any other embodiment or any combination thereof. Furthermore, equivalents and modifications not described above can also be used without deviating from the scope of protection of the appended claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 443,281

[0001] US 63 / 454,199

[0001] US 63 / 516,381

[0001] US 63 / 607,879

[0001]

Claims

[1] Composition, comprising: a support matrix; multiple photoluminescent nanostructures distributed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer. [2] Composition according to claim 1, wherein the multiple photoluminescent nanostructures comprise one or more indium phosphide (InP) based quantum dots, silver indium gallium sulfide (AIGS) based quantum dots or cadmium selenide (CdSe) based quantum dots. [3] Composition according to claim 1, wherein the at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer and the hindered amine stabilizer are stabilizing additives and wherein the stabilizing additives and the multiple photoluminescent nanostructures are distributed together as heterogeneous domains within the support matrix such that the photoluminescent nanostructures are in direct contact with the stabilizing additives. [4] Composition according to claim 1, further comprising a secondary antioxidant compound dispersed in the support matrix and configured to decompose at least one hydroperoxide. [5] Composition according to claim 4, wherein the secondary antioxidant compound comprises phosphorus and / or sulfur. [6] Composition according to claim 4, wherein the secondary antioxidant compound has the following structure: A-[(L)nR]m, where A is a structural unit that exhibits secondary antioxidant functionality; Each L is a linker group selected from phenyl, -O- and -S-; n is 0 or 1; Each R is independently a substituted or unsubstituted C6-40 hydrocarbon group; and m is a number from 1 to 6. [7] Composition according to claim 4, wherein the hindered amine stabilizer, the at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer and the secondary antioxidant are stabilizing additives, and wherein the multiple photoluminescent nanostructures and the stabilizing additives are distributed together as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives. [8] Composition according to claim 1, further comprising an additional base dispersed in the support matrix. [9] Composition according to claim 8, wherein the additional base comprises melamine or a melamine derivative. [10] Composition according to claim 8, wherein the additional base comprises a melamine-based product of a Mannich condensation. [11] Composition according to claim 8, wherein the additional base comprises a salt of melamine or a melamine derivative. [12] Composition according to claim 8, wherein the additional base comprises a triazine compound. [13] Composition according to claim 8, wherein the additional base comprises a cyanamide condensate. [14] Composition according to claim 8, wherein the additional base comprises an aromatic imine base. [15] Composition according to claim 8, wherein the additional base comprises a metal carbonate. [16] Composition according to claim 15, wherein the metal carbonate is lithium carbonate. [17] Composition according to claim 8, wherein the at least one of (i) the alkylalkoxysilane and the coordination polymer or (ii) a silanized coordination polymer, the hindered amine stabilizer and the additional base are stabilizing additives, and wherein the stabilizing additives and the multiple photoluminescent nanostructures are distributed together as heterogeneous domains within the support matrix, such that the photoluminescent nanostructures are in direct contact with the stabilizing additives. [18] Composition according to claim 1, further comprising a carrier particle. [19] Composition according to claim 18, wherein the carrier particle comprises a material for scattering light of at least one of: a wavelength absorbed by the luminescent nanostructures or a wavelength emitted by the luminescent nanostructures. [20] Composition according to claim 18, wherein the carrier particle has a band gap of more than 3 eV. [21] Composition according to claim 18, wherein the carrier particle comprises at least one of: an inorganic material, a metal oxide, a metal sulfide or one or more of SiO2, TiO2, ZnO or ZnS. [22] Composition according to claim 18, further comprising a coating that at least partially surrounds the carrier particle. [23] Composition according to claim 22, wherein the coating consists of at least one of: a) at least one material selected from the group consisting of: an alkoxysilane with a linear or branched alkyl substituent; an alkoxysilane with at least one phenyl, mercapto or amino substituent; an alkoxysilane with at least one crosslinkable reactive functional group; an alkoxysilane with at least one halide functional group; a tetraalkoxysilane; an alkali, alkaline earth or transition metal silicate; or a group (IV) or transition metal alkoxide; and / or b) at least one material selected from the group consisting of: a metal thiolate; a metal carboxylate; a fluoropolymer; a butylene / isoprene copolymer; a styrene-ethylene / butylene-styrene copolymer; a styrene-ethylene / propylene-styrene copolymer; polyvinylidene dichloride or a high-boiling wax. [24] Composition according to claim 22, wherein the coating comprises a silanized coordination polymer. [25] Composition according to claim 22, wherein the coating comprises a silanized coordination polymer which is the reaction product of an alkylalkoxysilane and a metal thiolate. [26] Composition according to claim 1, wherein the coordination polymer comprises a metal thiolate. [27] screen, having: comprising a hardened composition: a support matrix; multiple photoluminescent nanostructures distributed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer. [28] Screen according to claim 27, wherein the support matrix comprises a thermoplastic material or a precursor to a thermoplastic material and wherein the hardened composition further comprises a secondary antioxidant compound dispersed in the support matrix and configured to decompose at least one hydroperoxide. [29] Display device comprising: a screen comprising a hardened composition comprising: a support matrix; multiple photoluminescent nanostructures distributed within the support matrix; a hindered amine stabilizer; and at least one of (i) an alkylalkoxysilane and a coordination polymer or (ii) a silanized coordination polymer. [30] Display device according to claim 29, wherein the screen has a substantially planar solid structure and wherein the hardened composition further comprises an additional base dispersed in the support matrix. [31] Display device according to claim 30, wherein the additional base comprises a melamine-based product of a Mannich condensation.

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