Provided is a method for producing a β-sialon fluorescent material, comprising preparing a composition containing a silicon nitride that contains aluminium, oxygen, and europium; heat-treating the composition at a temperature in a range of 1300° C. or more and 1600° C. or less to obtain a heat-treated product; subjecting the heat-treated product to a temperature-decrease of from the heat treatment temperature to 1000° C. as a first temperature-decrease step; and subjecting the heat-treated product to a temperature-decrease of from 1000° C. to 400° C. as a second temperature-decrease step. The first temperature-decrease step has a temperature-decrease rate in a range of 1.5° C./min or more and 200° C./min or less, and the second temperature-decrease step has a temperature-decrease rate in a range of 1° C./min or more and 200° C./min or less.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

The present invention belongs to the technical field of inorganic luminescent materials, particularly relates to a nitride fluorescent material, and further discloses a light-emitting device containing such a fluorescent material. The nitride fluorescent material contains a compound with a structure like M.sub.mAl.sub.xSi.sub.yN.sub.3: aR, bEu, cCe. The fluorescent material has very high physical stability and chemical stability, and the fluorescent material is better in crystallization, and thus has relatively high external quantum efficiency. When being applied to a light-emitting device, the fluorescent material can fully exert the advantages of good stability and high external quantum efficiency, and the light-emitting efficiency and stability of the light-emitting device can be further improved.

The invention relates to a strontium aluminate mixed oxide precursor and a method for producing same, as well as to a strontium aluminate mixed oxide and method for producing same. The strontium aluminate mixed oxide precursor can be transformed into a strontium aluminate mixed oxide at relatively low temperature. The strontium aluminate mixed oxide is characterized by substantially spherically-shaped particles with a spongy- or porous bone-like microstructure. A luminescent material including a strontium aluminate mixed oxide is also provided.

Provided herein are phosphors of the general molecular formula:

A.sub.3-2xEu.sub.xMP.sub.3O.sub.9N,

wherein the variables are as defined herein. Methods of producing the phosphors are also provided. In some aspects, the present disclosure provides light-emitting devices comprising these phosphors.

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.

A method is disclosed for forming a blended phosphor composition. The method includes the steps of firing precursor compositions that include europium and nitrides of at least calcium, strontium and aluminum, in a refractory metal crucible and in the presence of a gas that precludes the formation of nitride compositions between the nitride starting materials and the refractory metal that forms the crucible. The resulting compositions can include phosphors that convert frequencies in the blue portion of the visible spectrum into frequencies in the red portion of the visible spectrum.

A method can be used for producing a powdery precursor material for an optoelectronic component having a first phase of the following general composition (Ca.sub.1-a-b-c-d-eZn.sub.dMg.sub.eSr.sub.cBa.sub.bX.sub.a).sub.2Si.sub.5N.sub.8, wherein X is an activator that is selected from the group of the lanthanoids and wherein the following applies: 0<a<1 and 0≦b≦1 and 0≦c≦ and 0≦d≦1 and 0≦e≦1. The method includes producing a powdery mixture of starting materials. The starting materials comprise ions of the aforementioned composition. At least silicon nitride having a specific surface area greater than or equal to 9 m/g is selected as a starting material and wherein the silicon nitride comprises alpha silicon nitride or is amorphous. The method also includes heat-treating the mixture under a protective gas atmosphere.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

The present invention relates to europium-, cerium-, samarium- or praseodymium-doped boronitrides, to a process for the preparation of these compounds, and to the use of the doped boronitrides according to the invention as conversion phosphors. The present invention furthermore relates to a light source which contains a doped boronitride according to the invention.