Growth of GaN Nanorods via Au Catalyst-Assisted CVD

Abstract

The growth of self-assembled, crystalline GaN nanorods was achieved by evaporating Ga in an atmosphere of NH3 at high temperature and under ambient pressure on Au-coated Si substrates via CVD. The structure and morphology of GaN nanorods were studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). It is found that GaN nanorods are of a perfect hexagonal wurtzite structure. SEM images have shown that the typical diameter and length of GaN nanorods are ∼ 10–80 nm and ∼ 2–3 μm, respectively. A particular feature is that each nanorod was capped with a nanoparticle at its very end, by which the diameter of the nanorod was confined. The growth mechanism of GaN nanorods has been discussed with respect to the vapor-liquid- solid (VLS) mechanism. This work opens up new approaches to prepare GaN nanorods and to use GaN nanorods for optoelectronic applications.