Thermal stability study of BaAl2Si2O8 : Eu2+ phosphor using its polymorphism for plasma display panel application

Abstract

We have evaluated the thermal stability of BaAl2Si2O8:Eu2+ (BAS:Eu2+) phosphor using its polymorph property and hexagonal and monoclinic crystal structure, depending upon firing temperature for plasma display panel application. When BAS:Eu2+ samples having each characteristic crystal structure were baked at 500 degrees C in air for 30 min, the baked monoclinic BAS:Eu2+ showed the same photoluminescence (PL) intensity as the fresh one, whereas the baked hexagonal one lost its PL intensity significantly, corresponding to about 34%. From analyses of electron spin resonance on Eu2+ and Rietveld refinement, the difference of thermal stability between hexagonal and monoclinic BAS:Eu2+ could be ascribed to both the crystal structure of host materials and the average interatomic distances between the Eu2+ ion and oxygen which plays the key role of shield for Eu2+ ions against an oxidation atmosphere.