A population of coated phosphor particles is presented. Each coated phosphor particle has a core including a Mn.sup.4+ doped phosphor and a shell including aluminum oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, silicon dioxide, hafnium oxide, indium oxide, indium tin oxide, potassium fluoride, titanium nitride, boron nitride, silicon nitride, a polymer material, or a combination thereof. A process for preparing the population of coated phosphor particles is also presented.

The present disclosure relates to a core-shell type quantum dot, comprising a quantum dot core, a light-transmitting inorganic mesoporous material layer on a surface of the quantum dot core, and a filler different from the inorganic mesoporous material in mesopores of the light-transmitting inorganic mesoporous material layer. The present disclosure also relates to the preparation and use of the core-shell type quantum dot core. The quantum dot core is coated with the light-transmitting inorganic mesoporous material and the mesopores of the inorganic mesoporous material are filled with the filler different from the inorganic mesoporous material, and the core-shell type quantum dots thus obtained not only have improved optical stability and chemical stability, but also have adjustable optical properties.

Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor having a composition represented by a general formula (1), a bulk density of 0.80 g/cm.sup.3 or more, and a mass median diameter (D50) of 30 μm or less: general formula: A.sub.2M.sub.(1-n)F.sub.6:Mn.sup.4+.sub.n (1), wherein 0<n≤0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.

A luminescent material represented by Formula 1, a method of preparing the same, and a light-emitting device including the same:

Formula 1

[A.sup.1.sub.nA.sup.2.sub.3][B.sub.2][X.sup.1.sub.mX.sup.2.sub.5]

A.sup.1, A.sup.2, B, X.sup.1, X.sup.2, n, and m in Formula 1 are as defined in the specification.

High photoluminescence, high stability, inorganic perovskite compounds comprising an alkali metal selected from potassium (K), rubidium (Rb), and cesium (Cs); copper (Cu); and at least one halogen selected from chlorine (Cl), bromine (Br), and iodine (I). The perovskites may be free of lead (Pb). The inorganic perovskite compound may be used in an optoelectronic device. The optoelectronic device optionally contains a phosphor such as a blue-emitting phosphor. The inorganic perovskite compound may be used as an anti-counterfeiting nanotaggant applied on or within an object that susceptible to counterfeiting to enable confirmation of an authentic object.

A colloid comprising a plurality of nanocrystals, each nanocrystal comprising rubidium, a group 11 element of the Periodic Table of Elements such as copper, silver or gold, and a halogen. A method for preparing said colloid via a room temperature ligand assisted re-precipitation (LAPP) method, wherein the ligand is an acidic ligand such as oleic acid. The precursor solution is formed in a polar organic solvent such as DMSO or DMF, and the precursor solution is contacted with a non-polar organic solvent and said ligand to precipitate the nanocrystals. A polymer comprising a plurality of nanocrystals, each nanocrystal having a particle size in the range of 1 nm to 50 nm; and a use of said colloid in optoelectronic devices, etc. are also disclosed.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100 C. to the emission intensity at 25 C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

Synthesizing a color stable Mn.sup.4+ doped phosphor by contacting a gaseous fluorine-containing oxidizing agent with a precursor of: A.sub.aB.sub.bC.sub.cD.sub.dX.sub.x:Mn.sup.4+; A.sub.aiB.sub.biC.sub.ciD.sub.dX.sub.xY.sub.d:Mn.sup.4+; A.sup.1.sub.3G.sub.2mnMn.sub.mMg.sub.nLi.sub.3F.sub.12O.sub.p; or AZF.sub.4:Mn.sup.4+. Where A is Li, Na, K, Rb, Cs, or a combination; B is Be, Mg, Ca, Sr, Ba, or a combination; C is Sc, Y, B, Al, Ga, In, Tl, or a combination; D is Ti, Zr, Hf, Rf, Si, Ge, Sn, Pb, or a combination; X is F or a combination of F and one of Br, Cl, and I; Y is O, or a combination of O and one of S and Se; A.sup.1 is Na or K, or a combination; G is Al, B, Sc, Fe, Cr, Ti, In, or a combination; Z is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y, In, or a combination.

The present invention relates to the field of luminescent crystals (LCs), and more specifically to Quantum Dots (QDs) of formula M.sup.1.sub.aM.sup.2.sub.bX.sub.c, wherein the substituents are as defined in the specification. The invention provides methods of manufacturing such luminescent crystals, particularly by dispersing suitable starting materials in the presence of a liquid and by the aid of milling balls; to compositions comprising luminescent crystals and to electronic devices, decorative coatings; and to intermediates comprising luminescent crystals.

The purpose of the present invention is to provide a fluoride phosphor (represented by the general formula A.sub.2SiF.sub.6:Mn) having high luminescence intensity and reliability, a high-luminance light-emitting device using this phosphor, and a production method for this phosphor. The production method for a fluoride phosphor represented by the general formula A.sub.2SiF.sub.6:Mn (where element A is an alkali metal element including at least potassium), wherein the fluoride phosphor production method comprises: a step of preparing an aqueous solution wherein element A and fluorine are dissolved in a solvent; and a step of adding, to the aqueous solution, solid silicon dioxide and a manganese compound that supplies manganese having a valence other than +7; wherein an added amount of the manganese compound is within a range such that an Mn content in the fluoride phosphor becomes at least 0.1 mass % and at most 1.5 mass %; and the fluoride phosphor precipitates as the silicon dioxide concurrently dissolves into the aqueous solution.