Tuning aerosol-assisted vapor phase processing towards low oxygen GaN powders

Herein, are reported studies of various experimental conditions aimed at optimizing the Aerosol-Assisted Vapor Phase Synthesis (AAVS) of GaN powders. In general, the process utilizes affordable oxygen-bearing gallium precursors in aqueous/methanol solutions to initially prepare nano-sized GaNxOy powders of spheroidal morphology. Subsequent pyrolysis of the GaNxOy intermediate in a NH3 atmosphere converts the powders to sub-micron, crystalline GaN powders that usually contain some residual oxygen. The application of appropriate solvents, e.g., methanol, in the aerosol powder generation stage and the use of pyrolysis temperatures in the range 900 - 1000 degrees C may improve both the extent of nitridation and, to certain degree, the control over average particle sizes. The characteristics of the AAVS-produced materials are compared with those for bulk GaN powders obtained by direct nitridation of commercial gallium oxide.