Single crystal growth of one-dimensional GaN nanostructures by halide vapor-phase epitaxy

High-quality one-dimensional GaN rods and nanowires were grown on Ni-coated c-plan sapphire substrate using halide vapor-phase epitaxy (HVPE). Their structure and optical properties were investigated by X-ray diffractometery, scanning and transmission electron microscopy, and photoluminescence techniques. A high density of straight and aligned one-dimensional GaN nanowires with a diameter of 80 nm was uniformly formed on the entire substrate at 700∘C. The X-ray diffraction patterns, transmission electron microscopic images, and selective area electron diffraction patterns indicate that the one-dimensional GaN are nanostructure pure single crystals preferentially oriented in the [001] direction. Photoluminescence analysis revealed that the HVPE grown GaN nanowires have high optical quality.