Degradation of Y2O3:Eu phosphor powders

Degradation of cathodoluminescent (CL) intensity and changes in the surface chemistry of Y2O3:Eu phosphor powders were investigated using CL spectroscopy and Auger electron spectroscopy (AES), respectively. Y2O3:Eu phosphor powders were exposed to an electron beam of energy 2 keV and a current density of 88.5 mA/cm2 at room temperature for different oxygen pressures. The degradation of CL intensity is due to the formation of a non-luminescent ''dead layer'' on the specimen surface, resulting from non-radiative recombination of electron-hole pairs via surface states. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)