Synthesis of GaN nanowires on gold-coated substrates by pulsed laser ablation

GaN nanowires were grown on gold-coated sapphire substrates by pulsed laser ablation of a target of GaN powder in low-pressure nitrogen gas. The laser ablation induced Ga and N plasma directly towards the substrate to initialize the vapor–liquid–solid (VLS) growth mechanism. The morphological and structural properties of the GaN nanowires were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The nanowires formed crystalline and have lengths from 300 to 500 nm with diameters of around 50 nm. The tips of the nanowires were observed to be more conducting which further confirmed the VLS growth mechanism. In addition, the electrical properties of these nanowires were also examined.