Ultraviolet irradiation-induced photoluminescence degradation in γ-alumina nanoparticles

The photoluminescence (PL) behavior of gamma-Al2O3 nanopowder is studied. Two emission peaks at 343 and 378 nm and a broadband ranging between 400 and 600 nm are observed. The peaks are attributed to F+ center, while the broadband is attributed to impurities. It is found that irradiating the sample with intense ultraviolet (UV) light can cause significant decrease in the intensity of the two peaks, but has no effect on the broadband. A simple model is proposed to explain the kinetics of UV irradiation-induced PL degradation. (c) 2006 American Institute of Physics.