TSL, OSL and ESR studies in ZnAl 2O 4:Tb phosphor

Abstract

ZnAl 2O 4:Tb phosphor was prepared by combustion synthesis. ZnAl 2O 4:Tb exhibits three thermally stimulated luminescence (TSL) peaks around 150, 275 and 350 °C. ZnAl 2O 4:Tb exhibits optically stimulated luminescence (OSL) when stimulated with 470 nm light. Electron spin resonance (ESR) studies were carried out to identify defect centres responsible for TSL peaks observed in ZnAl 2O 4:Tb. Two defect centres are identified in irradiated ZnAl 2O 4:Tb phosphor and these centres are assigned to V and F + centres. V centre appears to correlate with the 150 °C TSL peak, while F + centre could not be associated with the observed TSL peaks.