High quality GaN nanowires synthesized from Ga₂O₃ with graphite powder using VPE method

Synthesis of single-crystalline GaN nanowires on C-Al₂O₃ substrates in a vapor phase epitaxy process by the help of a Ni catalyst was realized. The GaN nanowires were grown at 1000-1100 °C using a mixed powder of Ga₂O₃ and graphite. GaN nanowires were found to have a single-crystalline hexagonal structure in a high-resolution transmission electron microscopy and X-ray scattering measurements in spite of atmospheric pressure growth. Diameters of the grown nanowires range from 60 to 120 nm, which are comparable to the diameters (10-80 nm) of hydrothermally prepared Ni nanoislands acting as a seed. This fact indicates that the diameter of GaN nanowires can be effectively tuned by controlling that of Ni catalysts.