Preparation and cathodoluminescence of mg-doped and Zn-doped GaN powders

In this paper, undoped, Mg- and Zn-doped gallium nitride powders were prepared by direct nitridation of Ga₂O₃ under a flowing NH₃ gas. The phase purity, morphology and cathodoluminescence spectra were presented. The Ga₂O₃ powders can be completely nitridized to GaN at 1000°C. The resultant GaN powders agglomerated together with submicron-sized polyhedral crystals. At room temperature, the Mg- and Zn-doped powders exhibit bright blue-violet emission at around 3.05 and 2.81 eV, respectively. This provides clear evidence that magnesium or zinc is incorporated into the GaN powders as an acceptor and suggests that the luminescent materials are promising candidates for optoelectronic applications.