The effect of electron recombination processes on the luminescence kinetics of ZnO ceramics

We have examined spectral and kinetic properties of photoluminescence of zinc oxide ceramics. Ceramics with and without addition of gallium have been studied. In the photoluminescence spectrum, we have observed two luminescence bands with maxima at 377-379 (near-band-edge luminescence) and 490 nm (green luminescence). It has been shown that the decay curves of the green luminescence are determined by two processes with different time and temperature properties, as well as the kinetics of release of carriers from electron traps. The relations between luminescence decay curves and mechanisms of luminescence excitation, as well as energy transfer processes, have been discussed.