Luminescence characteristics of blue emitting ZnAl2O4: Ce nanophosphors

Photoluminescence (PL) and Thermally stimulated luminescence (TSL) properties of both virgin and Ce doped ZnAl2O4 phosphors were investigated. The phosphors were synthesized via sol-gel route using the respective metal nitrates and citric acid. The nano particle nature of the phosphor was confirmed by X ray diffraction and dynamic light scattering techniques. Time resolved photoluminescence and photo-acoustic spectroscopic techniques were used to characterize the emission and excitation properties of the system. TSL properties of the nanophosphor showed a single glow peak at 468 K. Various trap parameters and the kinetics for the glow peak were evaluated assuming the Arrhenius behavior for the system. Electron spin resonance (ESR) technique was used to identify the chemical nature of the traps/defects responsible for the glow peak. The emission spectrum of the nanophosphor was plotted on a standard CIE diagram which suggested a strong bluish violet emission from the phosphor system. Further, the intensity of the phosphor was compared with that of commercial blue phosphor to know the commercial utility of the prepared phosphors.