High-quality one-dimensional GaN nanorods and nanowires were synthesized on Ni-coated c-plane sapphire substrates using halide vapor-phase epitaxy (HVPE). Their structure and optical properties were investigated by X-ray diffractometry, scanning and transmission electron microscopy, and photoluminescence techniques. A high density of straight and aligned onedimensional GaN nanowires with a diameter of 80 nm was uniformly formed on the entire substrate at 700 oC. The X-ray diffraction patterns, transmission electron microscope images, and selected area electron diffraction patterns indicate that the one-dimensional GaN nanostructures are pure single crystals and preferentially oriented in the [001] direction. We observed high optical quality of GaN nanowires by photoluminescence analysis.

Keywords: GaN, one-dimensional nanostructure, halide vapor-phase epitaxy, single crystal growth