New perspective in degradation mechanism of SrTiO3 : Pr,Al,Ga phosphors

Abstract

Under prolonged electron-beam exposure, perovskite-structured SrTiO3:Pr,Al,Ga (STO) phosphor can be easily reduced due to oxygen loss. In particular, it is well known that dissociative H2O molecules are well adsorbed on reduced STO surfaces. The hydroxyl species produced by such dissociative adsorption of H2O strongly decompose organic compounds chemisorbed on the surface from vacuum ambient used in display devices into carbon species due to the photocatalytic properties of STO. Consequently, it is very likely that this mechanism attributes to the larger amounts of carbon adsorption by electron-stimulated chemical reactions on the STO phosphor surface than other phosphors.