Synthesis of GaN nanowires by CVD method: effect of reaction temperature

GaN nanowires are fabricated on Si substrates by ammoniating Ga2O3/NiCl2 thin films using chemical vapour deposition method. The influence of reaction temperature on microstructure, morphology and optical properties of GaN nanowires is characterised by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrophotometer, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and photoluminescence. The results demonstrate that the GaN nanowires are single crystalline and exhibit hexagonal wurtzite symmetry. The best crystalline quality was achieved for an reaction temperature of 1150°C for 15 min. The growth process follows vapour–liquid–solid mechanism and Ni plays an important role as the nucleation point and as a catalyst.