Blue to yellow-orange emitting phosphor, and light source having such a phosphor
AssigneePatent-Treuhand-Gesellschaft fur elektrische Gluhlamplen mbH
InventorsTim Fiedler, Wolfram Hempel, Frank Jermann
Life of this patent
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Abstract
The phosphor having the composition xAE2SiO4:D.yREN, in which AE=(Sr, Ba, Ca, Mg) and D=Eu, and RE=La, Y, delivers a blue to yellow-orange emission and is distinguished by a high efficiency. It can be used for a very wide range of light sources.
Claims14
A blue to yellow-orange emitting phosphor from the class of the orthosilicates, which substantially has the composition AE2SiO4:D, wherein the phosphor has as component AE=Sr, Ba, Ca or Mg, alone or in combination, the activating doping D consisting of Eu and a small proportion x of AEO contained therein being replaced by REN, where RE=rare earth, so as to achieve the stoichiometry AE2-x-aRExEuaSiO4-xNx.
A process for producing a high-efficiency phosphor, comprising the steps of:
- a) providing the starting materials SiO2 and REN, AE precursors, and an Eu precursor, in a substantially stoichiometric ratio;
- b) mixing the starting materials to form a mixture;
- and
- c) annealing the mixture in an Al2O3, AlN or W or Mo crucible using a flux at approximately 1300 to 1700° C.
Dependencies are inferred from the claim text.