Patent ID: 8865305

Claim:
A method of making a core-shell phosphor, the method comprising: (a) mixing a lanthanum phosphate (LaPO 4 ) core with a shell precursor mixture comprising at least one compound of La, at least one compound of Ce, and at least one compound of Tb to form a core+shell precursor mixture under non-aqueous condition; (b) heating the core+shell precursor mixture to a temperature in a range from about 900° C. to about 1200° C. with an inorganic flux material in presence of a reductant to provide a heated core+shell precursor mixture; (c) cooling the heated core+shell precursor mixture to ambient temperature to provide a product core-shell phosphor dispersed in the inorganic flux material; and (d) separating the product core-shell phosphor from the inorganic flux material, wherein the method is effected through a molten salt method.