Solid polymer composition, free-standing film and light emitting device

Abstract

The present invention relates in a first aspect to a solid polymer composition (100) comprising green luminescent crystals (1), non-perovskite red phosphor particles, and a polymer (3). The molar ratio of the sum of (oxygen + nitrogen) to carbon of the polymer (3) is z, wherein z < 0.9, z < 0.75, in particular z < 0.4, in particular z < 0.3, in particular z < 0.25. A second aspect of the present invention relates to a self-supporting film comprising the solid polymer composition (100) of the first aspect. A third aspect of the present invention relates to a light emitting device comprising the solid polymer composition (100) according to the first aspect of the present invention, or the self-supporting film according to the second aspect of the present invention.

Description

Technical Field

[0001] The present invention relates in a first aspect to a solid polymer composition, in a second aspect to a self-supporting membrane, and in a third aspect to a light-emitting device. Background Technology

[0002] Existing liquid crystal displays (LCDs) or display components include components based on light-emitting crystals (quantum dots). Specifically, the backlight component of such an LCD may include RGB backlighting composed of red, blue, and green light. Currently, typical light-emitting crystals (quantum dots) are used to generate the backlight colors of such backlight components.

[0003] Manufacturing such components presents several challenges. One challenge is the embedding of the light-emitting crystals into the component. Due to the different chemical properties of the light-emitting crystals, incompatibility may exist between various embedding materials containing the crystals, or even between crystals embedded within the same material. This incompatibility can lead to the degradation of materials in the display component, thus potentially affecting the lifespan of the display.

[0004] Document US2017 / 0153382A1 discloses a quantum dot composite material, its manufacturing method, and its application. The quantum dot composite material comprises all-inorganic perovskite quantum dots and a modification protection on the surface of the all-inorganic perovskite quantum dots.

[0005] The literature, Tong-ng Xuan et al., “Super-Hydrophobic Cesium Lead Halide Perovskite Quantum Dot-Polymer Composites with High Stability and Luminescent Efficiency for Wide Color Gamut White Light-Emitting Diodes,” *Chemistry of Materials*, Vol. 31, No. 3, February 12, 2019, pp. 1042-1047, discloses a composite material strategy to improve the stability of water-sensitive CsPbBr3 quantum dots by embedding QDs within a superhydrophobic porous organic polymer framework.

[0006] Reference: Sijbom HF et al., “Luminescent Behavior of the K2SiF6:Mn” 4+"Red Phosphor at High Fluxes and at the Microscopic Level", ECS Journal of SolidState Science and Technology, 5(1), R3040-R3048 (2016). This paper discloses the fabrication of red non-perovskite phosphor particles. Summary of the Invention

[0007] The problem to be solved by the present invention is to provide a material composition that overcomes the shortcomings of the prior art.

[0008] The invention will be described in detail below. Unless otherwise indicated, the following definitions shall apply to this specification:

[0009] In the context of this invention, the terms “an,” “a,” “the,” and similar terms as used are to be construed as covering both the singular and plural, unless otherwise indicated herein or obviously contradictory to the context. The term “comprising” includes all of “including,” “consistently composed of,” and “comprises from.” Percentages are given in weight % unless otherwise indicated herein or obviously contradictory to the context. “Independently” means that a substituent / ion may be selected from one of the substituents / ions, or may be a combination of more than one of the above.

[0010] The term "phosphor" is known in the art to refer to materials that exhibit luminescence, particularly fluorescent materials. Thus, a red phosphor is a material that exhibits luminescence in the range of 610 to 650 nm, for example, around 630 nm. Similarly, a green phosphor is a material that exhibits luminescence in the range of 500 to 550 nm, for example, around 530 nm. Typically, phosphors are inorganic particles. The term "phosphor particle" refers to a particle of the aforementioned phosphor. This particle can be single-crystal or polycrystalline. In the context of this invention, the term particle refers to primary particles, not secondary particles (e.g., aggregates or agglomerates of primary particles).

[0011] The term "luminescent crystal" (LC) is known in the art and refers to crystals of 3 to 100 nm made of semiconductor materials. This term encompasses quantum dots typically 2 to 15 nm and nanocrystals typically larger than 15 nm and up to 100 nm (preferably up to 50 nm). Preferably, the luminescent crystal is approximately equiaxed (e.g., spheres or cubes). Particles are considered approximately equiaxed when the aspect ratio (longest:shortest direction) in all three orthogonal dimensions is 1 to 2. Therefore, components of an LC preferably contain 50 to 100% (n / n), more preferably 66 to 100% (n / n), and more preferably 75 to 100% (n / n) equiaxed nanocrystals.

[0012] As the term implies, LC stands for luminescence. In the context of this invention, the term luminescent crystal includes both single-crystal and polycrystalline particles. In the latter case, a single particle may contain several crystalline domains (grains) connected by crystalline or amorphous phase boundaries. A luminescent crystal is a semiconductor material exhibiting a direct bandgap (typically in the range of 1.1 to 3.8 eV, more typically 1.4 to 3.5 eV, and even more typically 1.7 to 3.2 eV). When irradiated with electromagnetic radiation equal to or greater than the bandgap, valence band electrons are excited to the conduction band, leaving electron-hole pairs in the valence band. The resulting excitons (electron-electron-hole pairs) then recombine radially in the form of photoluminescence, with maximum intensity concentrated near the LC bandgap value, exhibiting a photoluminescence quantum yield of at least 1%. LC can also exhibit electroluminescence upon contact with external sources of electrons and electron holes.

[0013] The term "perovskite crystal" is known, particularly for crystalline compounds that include a perovskite structure. This perovskite structure itself is known and described by the general formula M. 1 M 2 X3 includes cubic, pseudo-cubic, tetragonal, or orthorhombic crystals, where M 1 It is a cation with a coordination number of 12 (cuboctaeder) and M 2 X is a cation with a coordination number of 6 (octaederic) and X is an anion located at a cubic, pseudo-cubic, tetragonal, or orthorhombic position in the crystal lattice. In these structures, the selected cation or anion can be replaced by other ions (randomly or regularly up to 30 atomic percent), thereby forming a doped perovskite or a non-stoichiometric perovskite while still retaining its initial crystalline structure. The fabrication of such luminescent crystals is known, for example, from WO2018028869.

[0014] The term "polymer" is known to include organic synthetic materials comprising repeating units ("monomers"). The term polymer includes homopolymers and copolymers. Furthermore, it includes crosslinked and non-crosslinked polymers. Depending on the context, the term polymer should include both its monomers and oligomers. Polymers include silicone-based and non-silicone-based polymers, such as silicone-based polymers like silicone polymers, and non-silicone-based polymers like acrylate polymers, carbonate polymers, sulfone polymers, epoxy polymers, vinyl polymers, urethane polymers, imide polymers, ester polymers, furan polymers, melamine polymers, styrene polymers, norbornene polymers, and cyclic olefin copolymers. As is common in the art, polymers may include other materials such as polymerization initiators, stabilizers, solvents, and scattering particles.

[0015] Polymers can be further characterized by physical parameters such as polarity, glass transition temperature (Tg), Young's modulus, and light transmittance.

[0016] Polarity (z): The ratio (n / n) of heteroatoms (i.e., atoms other than carbon and hydrogen) to carbon is an indication of the polarity of the polymer. In the context of the present invention, polymers with 0.4 < z < 0.9 are considered polar, while polymers with z ≤ 0.4 are considered non-polar.

[0017] Glass transition temperature: (Tg) is a parameter well-known in the field of polymers; it describes the temperature at which an amorphous or semi-crystalline polymer changes from a glassy (hard) state to a more flexible, compliant or rubbery state. Polymers with a high Tg are considered "hard", while polymers with a low Tg are considered "soft". At the molecular level, Tg is not a discrete thermodynamic transition, but a temperature range where the mobility of the polymer chains significantly increases. However, the convention is to record a single temperature, which is defined as the midpoint of the temperature range, bounded by the tangents of two flat regions of the heat flow curve measured by DSC. Tg can be determined using DSC according to DIN EN ISO 11357-2 or ASTM E1356. This method is particularly suitable if the polymer is in the form of a bulk material. Alternatively, Tg can be determined according to ISO 14577-1 or ASTM E2546-15, by measuring the temperature-dependent micro- or nano-hardness using micro- or nano-indentation. This method is suitable for the light-emitting components and light-emitting devices disclosed herein. Suitable analytical devices are commercially available as MHT (Anton Paar), Hysitron TI Premier (Bruker) or Nano Indenter G200 (Keysight Technologies). The data obtained by temperature-controlled micro- and nano-indentation can be converted into Tg. Typically, the plastic deformation work or Young's modulus or hardness is measured as a function of temperature, and Tg is the temperature at which these parameters change significantly.

[0018] Young's modulus or elastic modulus is a mechanical property that measures the stiffness of a solid material. It defines the relationship between stress (force / unit area) and strain (proportional deformation) in a material in the linear elastic state of uniaxial deformation.

[0019] Light transmittance: Typically, the polymers used in the context of the present invention are light-transmissive to visible light, i.e., non-opaque, allowing the light emitted by the light-emitting crystal and the possible light of the light source used to excite the light-emitting crystal to pass through. The light transmittance can be determined by white light interferometry or ultraviolet-visible spectroscopy.

[0020] According to the present invention, the above problems are solved by the first aspect of the present invention, a solid polymer composition comprising a first class of luminescent materials selected from green luminescent perovskite crystals, a second class of luminescent materials selected from non-perovskite red phosphor particles and polymers. Suitable green luminescent perovskite crystals are selected from compounds of formula (I):

[0021] [M 1 A 1 ] a M 2 b X c (I), where:

[0022] A 1 It represents one or more organic cations, preferably formamidin (FA).

[0023] M 1 It represents one or more alkali metals, especially Cs.

[0024] M 2 Represents one or more M 1 Other metals, especially Pb,

[0025] X represents one or more anions selected from halide ions, halide-like ions, and sulfide ions, especially Br.

[0026] 'a' represents 1 to 4.

[0027] b represents 1 to 2,

[0028] c represents 3 to 9, and

[0029] Where M 1 Or A 1 Or M 1 and A 1 exist.

[0030] Specifically, formula (I) describes a luminescent crystal, where X represents a halide ion or halide-like ion, such as Br, Cl, CN, and especially Br.

[0031] Specifically, equation (I) describes the luminescent crystal, where M 2 This represents Pb.

[0032] Specifically, equation (I) describes the luminescent crystal, where A 1 Indicates FA (formamidin) and M 1 It does not exist.

[0033] Suitable non-perovskite red phosphor particles are Mn selected from compounds of formula (II). +4 Doped phosphor particles:

[0034] [A] x [MF y ]:Mn 4+ (II), where:

[0035] A represents Li, Na, K, Rb, Cs, or combinations thereof, especially K.

[0036] M represents Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or combinations thereof, especially Si.

[0037] x represents the absolute value of the charge of the [MFy] ion, specifically 2; and

[0038] Y represents 5, 6, or 7, especially 6.

[0039] The molar ratio of the total (oxygen + nitrogen) of the polymer to carbon is z, where z ≤ 0.9, z ≤ 0.75, especially z ≤ 0.4, especially z ≤ 0.3, especially z ≤ 0.25.

[0040] The solid polymer composition contains specific green luminescent crystals and specific non-perovskite red Mn. 4+ The doped phosphor and specific polymer matrix, when used in light-emitting devices, especially for LCD displays, give the light-emitting crystal and non-perovskite red phosphor high stability.

[0041] Specifically, Equation (I) describes a perovskite luminescent crystal that emits light with wavelengths from 500 nm to 550 nm when it absorbs blue light, particularly in the green spectrum around 527 nm.

[0042] In an advantageous embodiment, the green luminescent perovskite crystal is specifically a green luminescent perovskite crystal of formula (I'):

[0043] FAPbBr3 (I').

[0044] In another advantageous embodiment of the invention, the non-perovskite red phosphor particles are non-perovskite red phosphors of formula (II') Mn +4 Doped phosphor particles:

[0045] K2SiF6:Mn 4+ (II')

[0046] In an advantageous embodiment of the solid polymer composition, green luminescent perovskite crystals and non-perovskite red phosphor particles are embedded in the polymer.

[0047] In another advantageous embodiment of the solid polymer composition, green luminescent perovskite crystals and non-perovskite red phosphor particles are embedded in the polymer without encapsulation.

[0048] This specifically means that perovskite crystals and non-perovskite red phosphor particles do not require any encapsulation (e.g., particle surface protection or shelling) to embed in the polymer.

[0049] Specifically, both the green-emitting perovskite crystals and the non-perovskite red phosphor particles are distributed within the polymer, particularly essentially within the polymer, so that they do not extend beyond the surface of the polymer.

[0050] In another advantageous embodiment of the invention, the molar ratio of the total amount of (oxygen + nitrogen + sulfur + phosphorus + fluorine + chlorine + bromine + iodine) of the polymer to carbon is z < 0.9, preferably z < 0.4, more preferably z < 0.3, and most preferably z < 0.25.

[0051] In another advantageous embodiment of the solid polymer composition, the concentration difference Δc of Mn between the center of each non-perovskite red phosphor particle and a 100 nm region below the particle surface... Mn It is Δc Mn ≤50%, especially Δc Mn ≤20%.

[0052] Specifically, this concentration difference Δc Mn The cross-section of a single phosphor particle can be determined using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). This cross-section of a single phosphor particle can be prepared using focused ion beam (FIB).

[0053] Specifically, having the concentration difference Δc Mn Non-perovskite red phosphor particles do not exhibit a protective layer or shell, especially since no inorganic protective layer or shell is required on the surface for stabilization.

[0054] Specifically, because no protective layer or shell is required, the number of process steps in manufacturing non-perovskite red phosphor particles can be reduced.

[0055] The center of a particle specifically refers to the central region of the particle, particularly the core or core area of ​​the particle.

[0056] In contrast to known red phosphor particles, the non-perovskite red phosphor particles introduced in this invention advantageously do not contain an inorganic protective layer on their surface. Specifically, the non-perovskite red phosphor particles do not contain a metal oxide or K2SiF6 protective layer.

[0057] In a favorable implementation scheme, the inorganic protective layer can be omitted as follows, wherein the proposed implementation schemes can be independent of each other or can be combined:

[0058] Advantageously, the non-perovskite red phosphor particles have no inorganic surface coating. Specifically, the particles do not have an inorganic surface coating that is composed of a composition different from that of the core of each non-perovskite red phosphor particle. The absence of an inorganic surface coating specifically means that such a coating is substantially absent on the respective surface.

[0059] -Advantageously, each non-perovskite red phosphor particle exhibits Mn +4 A uniform distribution from the particle center to the particle surface. Therefore, specifically, each non-perovskite red phosphor has a substantially uniform Mn concentration c over the entire volume of its respective particle. Mn .

[0060] - Favorably, the manganese (Mn) concentration c of non-perovskite red phosphor particles Mn For c Mn ≥6 mol%, especially c Mn ≥9mol%, especially c Mn ≥11 mol%.

[0061] Unbound by theory, it is believed that, unlike known non-perovskite red phosphor particles that require an inorganic layer for stabilization, the polymer matrix in this paper provides stability.

[0062] In another advantageous embodiment of the invention, the size of the green luminescent perovskite crystal is from 3 nm to 100 nm. In particular, the size of the perovskite crystal can be determined by transmission electron microscopy.

[0063] In another advantageous embodiment of the invention, the Mn concentration c of the non-perovskite red phosphor particles... M It is 6≤c M ≤15mol%, preferably 10≤c M ≤14mol%, optimal selection 11≤c M ≤13mol%.

[0064] Advantageously, the particle size (volume-weighted average) of non-perovskite red phosphor particles is... p It is s p ≤10μm, advantageous s p ≤5μm, advantageous s p ≤2μm, advantageous s p ≤1μm, advantageous s p ≥50nm, advantageous s p ≥100nm, advantageous s p ≥200nm.

[0065] Furthermore, advantageously, the particle size (volume-weighted average) of the non-perovskite red phosphor particles is 200 nm ≤ s p ≤10μm, and very specifically 200nm≤s p ≤5μm.

[0066] Particle size is measured using standard characterization methods such as scanning electron microscopy (SEM).

[0067] Specifically, green luminescent perovskite crystals with dimensions ranging from 3 nm to 100 nm and s p ≤10μm, advantageous s p A combination of non-perovskite red phosphor particles ≤5 μm can produce an advantageous implementation. If particles of these respective sizes are embedded in a polymer, the amount of particles in the polymer can be optimized due to the favorable photoparticle interactions within this size range.

[0068] In an advantageous embodiment, the solid polymer composition comprises an acrylate, and very advantageously the polymer comprises an alicyclic acrylate.

[0069] In another advantageous embodiment, the solid polymer comprises a polyfunctional acrylate.

[0070] In another advantageous embodiment, the solid polymer is crosslinked. Crosslinking can be achieved as is known in the art, for example by adding a crosslinking agent or a polyvalent monomer.

[0071] The glass transition temperature T of an advantageous solid polymer composition g It is T g ≤120℃, favorable T g ≤100℃, favorable T g ≤80℃, favorable T g ≤70℃. (Each T) g According to DIN EN ISO 11357-2:2014-07, during the second heating cycle, a heating rate of 20 K / min is applied, starting at -90°C and continuing up to 250°C for measurement.

[0072] In another advantageous embodiment of the invention, the solid polymer composition comprises scattering particles selected from metal oxide particles and polymer particles. Advantageously, the particles are metal oxide particles, preferably selected from TiO2, ZrO2, Al2O3, and organopolysiloxanes.

[0073] In another advantageous embodiment, the solid polymer is semi-crystalline.

[0074] In another advantageous embodiment, the melting temperature T of the solid polymer p It is T p <140℃, T is preferred p <120℃, optimal temperature T p <100℃.

[0075] The solid polymer compositions of the present invention can be obtained using starting materials of formula (I) and formula (II) and monomers / oligomers of their respective polymers, similar to known methods. Therefore, the present invention provides a method for manufacturing a solid polymer composition comprising the steps of:

[0076] (a) Combining a compound of formula (I), a compound of formula (II), a monomer and / or oligomer of a polymer, optionally a diluent, optionally scattering particles, optionally a catalyst or other additive, thereby obtaining a first dispersion;

[0077] (b) Optionally remove the diluent to obtain ink;

[0078] (d) Curing the ink to obtain the solid polymer composition of the present invention.

[0079] The second aspect of the present invention relates to a self-supporting membrane comprising a solid polymer composition according to the first aspect of the present invention.

[0080] Advantageously, the self-supporting membrane emits green and red light in response to excitation by light with a wavelength shorter than the emitted green light.

[0081] Advantageously, the solid polymer composition is sandwiched between two barrier layers.

[0082] In another advantageous embodiment, the thickness t of this self-supporting membrane ssf It can be 0.001≤t ssf ≤10mm, preferably 0.01≤t ssf ≤0.5mm.

[0083] In another advantageous embodiment, a solid polymer is sandwiched between two barrier layers. Specifically, this sandwich arrangement refers to an arrangement having a barrier layer, a polymer, and another barrier layer in the horizontal direction. The two barrier layers of the sandwich structure can be made of the same barrier layer material or different barrier layer materials.

[0084] The technical effect of the barrier layer is to improve the stability of the luminescent perovskite crystal, especially its resistance to oxidation or moisture.

[0085] Specifically, such barrier layers are known in the art; they typically comprise materials / combinations of materials having low water vapor transmission rate (WVTR) and / or low oxygen transmission rate (OTR). By selecting such materials, degradation of the LC in response to exposure to water vapor and / or oxygen in components is reduced or even avoided. The preferred WVTR of the barrier layer or membrane at 40°C / 90% relative humidity and atmospheric pressure is <10(g) / (m³). 2 *day), more preferably less than 1(g) / (m 2 *day), the optimal value is less than 0.1(g) / (m 2*sky).

[0086] In one advantageous embodiment, the barrier membrane may be oxygen-permeable. In another advantageous embodiment, the barrier membrane is oxygen-impermeable and has an OTR (oxygen permeability) of <10 (mL) / (m²) at 23°C / 90% relative humidity and atmospheric pressure. 2 *day), more preferably <1(mL) / (m 2 *day), optimal value <0.1(mL) / (m 2 *sky).

[0087] In one embodiment, the barrier film is light-transmitting, i.e., the visible light transmittance is >80%, preferably >85%, and most preferably >90%.

[0088] Suitable barrier films can exist in monolayer form. Such barrier films are known in the art and comprise glass, ceramics, metal oxides, and polymers. Suitable polymers can be selected from polyvinylidene chloride (PVdC), cyclic olefin copolymers (COC), ethylene vinyl alcohol (EVOH), high-density polyethylene (HDPE), and polypropylene (PP); suitable inorganic materials can be selected from metal oxides, SiO₂, etc. x Si x N y AlO x Most preferably, the polymer moisture-proof material comprises a material selected from PVdC and COC.

[0089] Advantageously, the polymeric oxygen barrier material comprises a material selected from EVOH polymers.

[0090] Suitable barrier films can exist in a multilayer form. Such barrier films are known in the art and typically comprise a substrate, such as PET with a thickness of 10 to 200 μm, and a matrix containing materials selected from SiO₂. x and AlO x The material can be a thin inorganic layer, or an organic layer based on liquid crystals embedded in a polymer matrix, or an organic layer of a polymer having the desired barrier properties. Possible polymers for such organic layers include, for example, PVdC, COC, and EVOH.

[0091] The self-supporting membrane of the present invention can be obtained using methods similar to those known, employing starting materials of formulas (I) and (II) and monomers / oligomers of their respective polymers. Therefore, the present invention provides a method for manufacturing a self-supporting membrane, comprising the steps of:

[0092] (a) Combining a compound of formula (I), a compound of formula (II), a monomer and / or oligomer of a polymer, optionally a diluent, optionally scattering particles, optionally a catalyst or other additive, thereby obtaining a first dispersion;

[0093] (b) Optionally remove the diluent to obtain ink;

[0094] (c) The ink is coated onto the barrier film to obtain the coated barrier film;

[0095] (d) Laminating the coated barrier film with the second barrier film;

[0096] (e) Curing the laminated barrier film to obtain the self-supporting film of the present invention;

[0097] The invention is simple to manufacture and can be easily applied to existing production lines.

[0098] The third aspect relates to a light-emitting device, preferably a liquid crystal display. The light-emitting device comprises a solid polymer composition according to the first aspect of the invention or a self-supporting film according to the second aspect of the invention.

[0099] An advantageous embodiment of the light-emitting device comprises an array of more than one blue LED, wherein the LED array substantially covers the entire liquid crystal display area. Additionally, a diffuser plate is disposed between the array of more than one blue LED and a self-supporting film.

[0100] In another advantageous embodiment of the invention, each of one or more blue LEDs in the array is adapted to switch between on and off at a frequency f: f ≥ 150 Hz, preferably f ≥ 300 Hz, and very preferably f ≥ 600 Hz. Attached Figure Description

[0101] The invention will be better understood from the following detailed description, and objectives beyond those described above will become clear. This description refers to the accompanying drawings, in which:

[0102] Figure 1 A diagram showing a solid polymer composition according to one embodiment of the present invention is provided;

[0103] Figure 2 An illustration shows a sheet material according to one embodiment of the present invention; and

[0104] Figure 3 A light-emitting device according to an embodiment of the present invention is shown. Detailed Implementation

[0105] The embodiments, examples, and experiments illustrating or leading to the implementation, aspects, and advantages of the invention will be better understood from the following detailed description. This description refers to the accompanying drawings, in which:

[0106] Figure 1A diagram of a solid polymer composition 100 according to an embodiment of the first aspect is shown, wherein the solid polymer composition comprises a green luminescent perovskite crystal 1 of formula (I), a non-perovskite red phosphor crystal 2 of formula (II), and a polymer 3. The molar ratio of the total (oxygen + nitrogen) of the polymer to carbon is z, wherein z ≤ 0.9, z ≤ 0.75, particularly z ≤ 0.4, particularly z ≤ 0.3, particularly z ≤ 0.25.

[0107] Figure 1 Further embodiments of the solid polymer composition may include additional features according to the first aspect of the invention.

[0108] Figure 2 An illustration shows one embodiment of a self-supporting membrane according to a second aspect of the invention. In an advantageous embodiment as shown in the figure, the self-supporting membrane may comprise a barrier layer 4 sandwiched within a solid polymer composition 100.

[0109] Figure 3 An illustration shows an embodiment of a light-emitting device according to a third aspect of the invention, particularly a liquid crystal display (LCD). Advantageously, the light-emitting device comprises... Figure 1 The solid polymer composition 100 shown or Figure 2 The self-supporting film is shown. Advantageously, the light-emitting device includes more than one blue LED 6, wherein the LED covers substantially the entire liquid crystal display area 5. Specifically, a diffuser plate is arranged between the array of more than one blue LED and the self-supporting film (the diffuser plate is not shown in the figure).

[0110] Example

[0111] Example 1: Preparation of a self-supporting membrane comprising the solid polymer composition described herein:

[0112] Green perovskite QD (FAPbBr3): Formamidinium lead tribromide (FAPbBr3) was synthesized by grinding PbBr2 and FABr. Specifically, pure cubic FAPbBr3 was obtained by grinding 16 mmol PbBr2 (5.87 g, 98% ABCR, Karlsruhe (DE)) and 16 mmol FABr (2.00 g, Greatcell Solar Materials, Queanbeyan (AU)) with yttrium-stabilized zirconia beads (5 mm in diameter) for 6 hours, as confirmed by XRD. The orange FAPbBr3 powder was added to oleamide (80-90, Acros Organics, Geel (BE)) (weight ratio FAPbBr3:oleamide = 100:15) and toluene (>99.5%, Puriss, Sigma-Aldrich). The final concentration of FAPbBr3 was 1 wt%. The mixture was then dispersed by ball milling for 1 hour using yttrium-stabilized zirconia beads with a diameter of 200 μm under ambient conditions (unless otherwise defined, the atmospheric conditions used for all experiments were: 35 °C, 1 atm, in air) to produce green luminescent ink.

[0113] Film formation: 0.1 g of green ink was mixed with 1 wt% of photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TCI Europe, Netherlands), 2 wt% polymer scattering particles (organopolysiloxane, ShinEtsu, KMP-590), and 10 wt% non-perovskite red phosphor particles (“KSF”, K2SiF6:Mn). 4+ A commercially available UV-curable monomer / crosslinker mixture (0.7g FA-513AS, Hitachi Chemical, Japan / 0.3g Miramer M240, Miwon, South Korea) in solid form was mixed in a high-speed mixer and toluene was evaporated under vacuum (<0.01 mbar) at room temperature.

[0114] Non-perovskite red phosphor particles K2SiF6:Mn 4+ These particles are manufactured using existing techniques. The known diameter of these particles is typically 2 to 50 μm.

[0115] The particles were manufactured, for example, by the method disclosed in ICP-MS by Sijbom HF et al., which showed that the Mn concentration of the formed KSF particles was 1.5 mol%. SEM analysis using EDX plotting of Mn further showed that Mn was uniformly distributed from the particle core to the particle surface within the KSF particles, demonstrating that the KSF particles had no inorganic shell or any other encapsulation.

[0116] The volume-weighted average KSF particle size was 3 μm, as determined by SEM.

[0117] The resulting mixture was then coated at a 50 μm thickness onto a 100 μm barrier film (supplier: I-components (Korea); product: TBF-1007), and then laminated with a second barrier film of the same type. The laminated structure was subsequently UV-cured for 60 seconds (UVAcube100, equipped with a mercury lamp and quartz filter, Hoenle, Germany), thereby obtaining a self-supporting film in which the solid polymer composition of the present invention is sandwiched between two barrier layers. The resulting KSF amount / film area is approximately 6 g / m². 2 .

[0118] Performance testing: The initial properties of the obtained membrane show that K2SiF6:Mn 4+ The film emits green light at a wavelength of 526 nm (22 nm for FWHM) and red light. When an LED blue light source (450 nm emission wavelength, with two intersecting prism sheets (X-BEF) and a brightness enhancement film (DBEF)) is placed on top of the QD film (optical performance measured using a Konica Minolta CS-2000), the film's color coordinates (CIE1931) are x = 0.23 and y = 0.20.

[0119] The glass transition temperature (Tg) of the UV-cured solid polymer composition was determined by DSC according to DIN EN ISO 11357-2:2014-07, with an initial temperature of -90°C and an ending temperature of 250°C, and a heating rate of 20 K / min in a nitrogen atmosphere (20 ml / min). The purge gas was nitrogen (5.0 g) at a rate of 20 ml / min. A Phoenix (Netzsch) DSC 204F1 system was used. g Measurements were taken during the second heating cycle (the first heating from -90°C to 250°C showed an overlap effect in addition to the glass transition). For DSC measurements, the solid polymer composition was removed from the membrane by delamination of the barrier film. The measured Tg of the UV-cured resin composition was 75°C.

[0120] The stability of the membrane was tested by placing it in a high-intensity blue light box (supplier: Hoenle; model: LEDCUBE 100IC) and irradiating it with blue LED light for 150 hours. The light box exhibited a membrane temperature of 410 mW / cm² at 50°C. 2 The blue light flux on the membrane was measured. Furthermore, the membrane was tested for 150 hours in a climate chamber at 60°C and 90% relative humidity. Changes in optical parameters after the membrane stability test were measured using the same procedure as for the initial performance measurement (as described above). The changes in optical performance are as follows:

[0121]

[0122] Example 2: Preparation of a self-supporting membrane comprising a solid polymer composition with large KSF particle size.

[0123] KSF particles with a volume-weighted average particle size of 20 μm (measured by SEM) were synthesized similarly to those in Experiment 1. ICP-MS showed that the Mn concentration of the formed KSF particles was 1.6 mol%. SEM analysis with EDX plots of Mn further showed that Mn was uniformly distributed from the particle core to the particle surface within the KSF particles, indicating that the KSF particles had no inorganic shell or any other encapsulation. These KSF particles were used to prepare films using the same materials (perovskite crystals, monomer / crosslinker mixture, photoinitiator, scattering particles) and the same color coordinates as in Example 1. To achieve the same film color coordinates as in Example 1, the KSF concentration had to be increased from 10 wt% (as in Example 1) to 25 wt%. This resulted in a KSF amount / film area of ​​approximately 15 g / m². 2 This indicates that for displays containing this film, a KSF particle size of 3 μm is preferred over 20 μm because the KSF amount / film area is 2.5 times lower, thus requiring less KSF particle amount / film area and ultimately fewer KSF particles.

[0124] Conclusion: These results demonstrate that a self-supporting luminescent film can be obtained, thereby achieving green luminescent perovskite crystals and non-perovskite red phosphor particles (K2SiF6:Mn) when tested under high blue light flux and high temperature / humidity conditions. 4+ Both exhibited good chemical compatibility and high stability. Furthermore, these results indicate that small KSF particle size is preferred.

Claims

1. A solid polymer composition (100) comprising: -Green luminescent perovskite crystals (1), -Non-perovskite red phosphor particles (2), - Scattering particles, and -Polymer(3), The green luminescent perovskite crystal (1) is of formula (I'): FAPbBr3(I') The non-perovskite red phosphor particle (2) is Mn of formula (II'). +4 Doped phosphor particles: K2SiF6:Mn 4+ (II’) The molar ratio of the total (oxygen + nitrogen) to carbon in polymer (3) is z, where z ≤ 0.

4. The volume-weighted average particle size s of the non-perovskite red phosphor particles (2) p It is s p ≤10µm, and The scattering particles are selected from metal oxide particles and polymer particles.

2. The solid polymer composition (100) according to claim 1, wherein the green luminescent perovskite crystal and the non-perovskite red phosphor particles are embedded in the polymer without encapsulation.

3. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the concentration difference Δc of Mn between the center of each non-perovskite red phosphor particle (2) and a 100 nm region below the surface of the respective red phosphor particle is... Mn It is Δc Mn ≤50%.

4. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the concentration c of Mn in each non-perovskite red phosphor particle (2) is... Mn The volume of each non-perovskite red phosphor particle is uniform.

5. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the non-perovskite red phosphor particles (2) have no inorganic surface coating.

6. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the non-perovskite red phosphor particles (2) are not composed of an inorganic surface coating that is different from the composition of the core of each non-perovskite red phosphor particle (2).

7. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the Mn concentration c of the non-perovskite red phosphor particles (2) is... Mn It is C Mn ≥6 mol%.

8. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the polymer (3) comprises acrylate.

9. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the polymer (3) comprises an alicyclic acrylate.

10. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the glass transition temperature T of the solid polymer composition (100) is... g It is T g ≤120°C.

11. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the solid polymer composition (100) comprises scattering particles selected from polymer particles.

12. The solid polymer composition (100) according to any one of claims 1 to 2, wherein the solid polymer composition (100) comprises scattering particles selected from organopolysiloxanes.

13. A self-supporting membrane comprising the solid polymer composition (100) according to any one of claims 1 to 12.

14. The self-supporting membrane according to claim 13, wherein the solid polymer composition (100) is sandwiched between two barrier layers (4).

15. A light-emitting device comprising a solid polymer composition (100) according to any one of claims 1-12, or comprising a self-supporting film according to claim 13 or 14.

16. The light-emitting device according to claim 15, wherein it is a liquid crystal display (LCD).

17. The light-emitting device according to claim 15 or 16, comprising an array (6) of more than one blue LED. The array (6) of LEDs covers the entire liquid crystal display area (5), and A diffuser plate is arranged between an array (6) of more than one blue LED and a self-supporting membrane.

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