Synthesis routes and characterization of high-purity, single-phase gallium nitride powders

Synthesis of high-purity, single-phase gallium nitride powder has been achieved in a hot-wall tube furnace via (i) the reaction of gallium with ammonia (NH3) and (ii) the conversion of gallium oxide (Ga2O3). For complete reaction, the optimum temperatures, NH3 flow rates, and boat positions relative to the NH3 inlet mere 975 degrees C, 400 standard cubic centimeters per minute (seem), and 50 cm, respectively, for the gallium-NH3 reaction, and 1050 degrees C, 500 seem, and 50 cm, respectively, for the Ga2O3, conversion. Polyhedra of various shapes were obtained from both processes; some rod-shaped crystals also were observed in the material derived from Ga2O3.