Narrow band red phosphor
AssigneeIntematix Corporation
InventorsHaoguo Zhu, Yi-Qun Li
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Abstract
A narrow band red phosphor may have a general composition MSxSeyAz:Eu, wherein M is at least one of Mg, Ca, Sr and Ba, A is at least one of C, N, B, P and a monovalent combining group NCN (cyanamide), and may in some embodiments further include one or more of O, F, Cl, Br and I. In embodiments 0.8<x+y<1.25 and 0<z≤0.05, and in some embodiments x, y and z are determined strictly by charge balancing. A white light emitting device may comprise: a blue and/or UV excitation source; a narrow band red phosphor of the present invention; and phosphors with peak emission at shorter wavelengths, such as yellow, green, yellow/green and/or blue.
Claims30
A red-emitting phosphor, comprising:
- phosphor particles with a composition represented by the chemical formula MSxSeyAz:Eu, wherein
- M is at least one of Mg, Ca, Sr and Ba;
- A comprises one or more of carbon, nitrogen, boron, phosphorous and a monovalent combining group NCN (cyanamide);
- x≥0;
- y≥0.1;
- 0<z≤0.05;
- and
- 0.8<x+y<1.25.
A method of making a phosphor, comprising:
- combining in a crucible MSeO4:Eu crystals, powdered sulphur and powdered material comprising A;
- and
- sintering the combined materials;
- grinding the sintered material;
- and
- washing the ground material;
- wherein M is at least one of Mg, Ca, Sr and Ba;
- wherein A comprises one or more of carbon, nitrogen, boron, phosphorous and the monovalent combining group NCN(cyanamide);
- wherein the amount of S is chosen to provide a desired stoichiometric ratio of Se to S;
- wherein the amount of A is between 2.0 and 5.5 wt. %;
- and
- wherein said phosphor has a composition represented by the chemical formula MSxSeyAz:Eu, wherein 0<z≤0.5, x≥0, y≥0.1, and 0.8<x+y<1.25.
Dependencies are inferred from the claim text.