An oxide fluorescent material comprises: at least one first element M.sup.1 selected from Li, Na, K, Rb, and Cs; at least one second element M.sup.2 selected from Mg, Ca, Sr, Ba, and Zn; at least one third element M.sup.3 selected from B, Al, Ga, In, and rare earth elements; at least one fourth element M.sup.4 selected from Si, Ti, Ge, Zr, Sn, Hf, and Pb; O; and Cr, wherein when the molar ratio of the at least one fourth element M.sup.4 in 1 mol of the composition is 5, the molar ratio of the at least one first element M.sup.1 is 0.7 or more and 1.3 or less, the molar ratio of the at least one second element M.sup.2 is 1.5 or more and 2.5 or less, the molar ratio of the at least one third element M.sup.3 is 0.7 or more and 1.3 or less, the molar ratio of oxygen is 12.9 or more and 15.1 or less, and the molar ratio of Cr is more than 0 and 0.2 or less, and wherein the oxide fluorescent material has a light emission peak wavelength in a range of 700 nm or more and 1,050 nm or less in a light emission spectrum of the oxide fluorescent material.

An LED-filament comprising: a partially light-transmissive substrate; a plurality of blue LED chips mounted on a front face of the substrate; first broad-band green to red photoluminescence materials and a first narrow-band manganese-activated fluoride red photoluminescence material covering the plurality of blue LED chips and the front face of the substrate; and second broad-band green to red photoluminescence materials covering the back face of the substrate. The LED-filament can further comprise a second narrow-band manganese-activated fluoride red photoluminescence material on the back face of the substrate in an amount that is less than 5 wt % of a total red photoluminescence material content on the back face of the substrate.

A beta-voltaic device made up of silica covered scintillating particles incorporated within an isotope absorbing layer to produce an improved power source. Lost beta particles are converted to UV light which is also converted to power in a beta-voltaic converter. The addition of the scintillating particles effectively increases the power efficiency of a BV device while maintaining the slim profile and smaller size of the power source. This arrangement makes possible implementation in space, defense, intelligence, medical implants, marine biology and other applications.

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.

Ternary transition metal halides are described herein. The ternary transition metal halides may be used as scintillator materials.

A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn.sup.4+ doped phosphor, wherein the lighting apparatus has a color shift of ≤1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm.sup.2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.

A phosphor powder contains an EU-activated β-type sialon phosphor particles. When a median diameter in the phosphor powder having not been subjected to an ultrasonic homogenizer treatment is set as D1 and a median diameter in the phosphor powder having been subjected to an ultrasonic homogenizer treatment is set as D2, 1.05≤D1/D2≤1.70. A dispersion liquid in which 30 mg of the phosphor powder is uniformly dispersed in 100 ml of a 0.2% concentration of a sodium hexametaphosphate aqueous solution is added to a columnar container of which a bottom surface has an inner diameter of 5.5 cm. Then, the dispersion liquid is irradiated with ultrasonic waves for 3 minutes at a frequency of 19.5 kHz, and an output of 150 W, in a state where a cylindrical tip, which has an outer diameter of 20 mm, of an ultrasonic homogenizer is immersed in the dispersion liquid in ≥1.0 cm.

A fluoride phosphor, a composition of which is represented by General Formula (1), in which in a case where a cumulative 50% value is denoted by D.sub.50 and a cumulative 90% value is denoted by D.sub.90 in a volume-based particle size distribution curve obtained by a laser diffraction scattering method, D.sub.50 is 0.1 to 9.5 μm and D.sub.90 is 0.5 to 16 μm. General Formula (1): A.sub.2M.sub.(1-f)F.sub.6:Mn.sup.4+.sub.n In General Formula (1), an element A is one or more alkali metal elements including K, an element M is a Si simple substance, a Ge simple substance, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf, and 0<n≤0.1 is satisfied.

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.

Disclosed are quantum dots including a luminescent dopant. More particularly, each of the quantum dots according to an embodiment of the present invention includes a core and a shell surrounding the core, wherein at least one of an interior of the core and an interface between the core and the shell is doped with a luminescent group I dopant.