Reversible ultraviolet-induced photoluminescence degradation and enhancement in GaN films

Research was conducted to prove that the photoinduced modifications of undoped GaN thin films are more complex than those of earlier experiments. Previous experiments focused on the photoluminescence efficiencies of the yellow and blue bands during ultraviolet laser irradiation of samples of GaN thin films grown on sapphire. Mechanisms that may explain the luminescence pathways and defects involved are presented.