Growth of GaN nanowires by ammoniating Ga_2O_3 thin films deposited on quartz with radio frequency magnetron sputtering

摘要

GaN nanowires have been synthesized by ammoniating Ga_2O_3 oxide thin films. Ga_2O_3 films with a thickness of approx 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 mu m. The achievement of GaN nanowires by ammoniating Ga_2O_3 presents a novel method for synthesizing one-dimensional nanometre materials without the assistance of a template or a catalyst.