Growth of GaN nanowires by ammoniating Ga2O3 thin films deposited on quartz with radio frequency magnetron sputtering

GaN nanowires have been synthesized by ammoniating Ga2O3 oxide thin films. Ga2O3 films with a thickness of about 500 nm were deposited on quartz substrates by radio frequency magnetron sputtering. X-ray diffraction, scanning electronic microscope, transmission electronic microscope and high-resolution TEM results show that the majority of the GaN nanowires have a single-crystal hexagonal wurtzite structure with major axis [110] alignment. A minority are polycrystalline, composed of overlapped parallelepiped GaN nanocrystals, which gives the wires a herringbone topography. The diameters of the wires range from 10 to 90 nm and the lengths are up to 50 microns. The achievement of GaN nanowires by ammoniating Ga2O3 presents a novel method for synthesizing 1D nanometer materials without the assistance of a template or a catalyst.