A compound of the general formula (I): A.sub.3BF.sub.2M.sub.1−xT.sub.xO.sub.2−2xF.sub.4+2x doped with Mn(IV), in which A is selected from the group consisting of Li, Na, K, Rb, Cs, Cu, Ag, Tl, NH4, NR4 and mixtures of two or more thereof, where R is an alkyl or aryl group, B is selected from the group consisting of H and D and mixtures thereof, where D is Deuterium, M is selected from the group consisting of Cr, Mo, W, Te, Re and mixtures of two or more thereof, T is selected from the group consisting of Si, Ge, Sn, Ti, Pb, Ce, Zr, Hf and mixtures of two or more thereof, and 0≤x≤1.

A compound of the general formula (I): A.sub.3BF.sub.2M.sub.1−xT.sub.xO.sub.2−2xF.sub.4+2x doped with Mn(IV), in which A is selected from the group consisting of Li, Na, K, Rb, Cs, Cu, Ag, Tl, NH4, NR4 and mixtures of two or more thereof, where R is an alkyl or aryl group, B is selected from the group consisting of H and D and mixtures thereof, where D is Deuterium, M is selected from the group consisting of Cr, Mo, W, Te, Re and mixtures of two or more thereof, T is selected from the group consisting of Si, Ge, Sn, Ti, Pb, Ce, Zr, Hf and mixtures of two or more thereof, and 0≤x≤1.

A light source for emitting emitted light having an SPD comprising: (a) a plurality of light emitters including at least one violet solid-state emitter; (b) at least one phosphor; wherein said light emitters and said at least one phosphor being configured such that: at least 25% of the power within the SPD is in the range 390-420 nm, and the emitted light has a chromaticity which is within a Duv distance of less than 5 points from the Planckian locus.

Provided is an aluminate fluorescent material having a high emission intensity and having a composition containing a first element that contains one or more of Ba and Sr, and a second element that contains Mg and Mn. In the composition, when a molar ratio of Al is 10, a total molar ratio of the first element is a parameter a, a total molar ratio of the second element is a parameter b, a molar ratio of Sr is a product of a parameter m and the parameter a, a molar ratio of Mn is a product of a parameter n and the parameter b. The parameters a and b satisfy 0.5<b<a≦0.5b+0.5<1.0, the parameter m satisfies 0≦m≦1.0, and the parameter n satisfies 0.4≦n≦0.7.

A core-shell quantum dot comprising zinc, a core comprising a first semiconductor nanocrystal material; and a semiconductor nanocrystal shell disposed on the core, wherein the core-shell quantum dot does not comprise cadmium, and does comprise zinc, tellurium, selenium, and aluminum.

A core-shell quantum dot comprising zinc, a core comprising a first semiconductor nanocrystal material; and a semiconductor nanocrystal shell disposed on the core, wherein the core-shell quantum dot does not comprise cadmium, and does comprise zinc, tellurium, selenium, and aluminum.

There is provided a fluoride phosphor composite including: fluoride phosphor core particles that may be expressed by the empirical formula A.sub.xMF.sub.y:Mn.sup.4+, wherein A may be at least one selected from the group consisting of Li, Na, K, Rb, and Cs, M may be at least one selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn, the composition ratio (x) of A may satisfy 2≦x≦3, the composition ratio (y) of F may satisfy 4≦y≦7, each fluoride phosphor composite particle may be coated with a Mn-free fluoride coating. The Mn-free fluoride coating may have a thickness less than or equal to 35% of the size of each fluoride phosphor composite particle.

There is provided a fluoride phosphor composite including: fluoride phosphor core particles that may be expressed by the empirical formula A.sub.xMF.sub.y:Mn.sup.4+, wherein A may be at least one selected from the group consisting of Li, Na, K, Rb, and Cs, M may be at least one selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn, the composition ratio (x) of A may satisfy 2≦x≦3, the composition ratio (y) of F may satisfy 4≦y≦7, each fluoride phosphor composite particle may be coated with a Mn-free fluoride coating. The Mn-free fluoride coating may have a thickness less than or equal to 35% of the size of each fluoride phosphor composite particle.

Described are Zn.sub.xCd.sub.1-xS.sub.ySe.sub.1-y/ZnS.sub.zSe.sub.1-z core/shell nanocrystals, CdTe/CdS/ZnS core/shell/shell nanocrystals, optionally doped Zn(S,Se,Te) nano- and quantum wires, and SnS quantum sheets or ribbons, methods for making the same, and their use in biomedical and photonic applications, such as sensors for analytes in cells and preparation of field effect transistors.

A light source for emitting emitted light having an SPD comprising: (a) a plurality of light emitters including at least one violet solid-state emitter; (b) at least one phosphor; wherein said light emitters and said at least one phosphor being configured such that: at least 25% of the power within the SPD is in the range 390-420 nm, and the emitted light has a chromaticity which is within a Duv distance of less than 5 points from the Planckian locus.