PREPARATION METHOD OF ALKALI EARTH METAL THIOGALLATE PHOSPHORS

摘要

Provided is a method for preparing alkali earth metal thiogallate phosphors, which carries out heat treatment at temperature lower than that of a conventional method and provides alkali earth metal thiogallate phosphors having good light emitting property at a condition in which use of flux and toxic components is excluded. The method for preparing alkali earth metal thiogallate phosphors comprises the steps of: (1) mixing alkali earth metal 8-49wt%, gallium 49-78wt%, and an activator metal 0.055-32wt% to prepare an aqueous solution of mixed metals; (2) subjecting the aqueous solution of mixed metals to coprecipitation under a range of pH 6-11 using a metal sulfide precipitator, followed by carrying out filtration and drying to prepare thiogallate phosphor precursors; and (3) heat-treating the thiogallate phosphor precursors at 600-950‹C under a mixed gas atmosphere of nitrogen and hydrogen.