Growth of One-dimensional Gallium Nitride Nano- and Microstructures in an Alumina Matrix Containing Gallium Oxide

다국어 초록 (Multilingual Abstract)

Nanostructures of gallium nitride (GaN) with a direct bandgap of 3.4 eV are of interest because of their great prospects in fundamental physical science, novel nanotechnology applications, and significant potential in optoelectronics.1 One-dimensional nanostructures such as nanowires and nanorods have been grown by various methods. Most of them are based on the chemical vapor deposition (CVD) of GaN on the substrate. The substrate is coated with transition metals such as Ni,2,3 Fe,4,5 Co,5 In,6 and Au,7 which inevitably results in undesired contamination within GaN nanostructures. One of the useful synthetic methods to avoid the contamination is to employ the so-called confined reactor such as the carbon nanotube8 or the anodic alumina membrane.9 GaN nanowires were obtained by placing the confined reactor on a mixture of Ga and Ga2O3 and calcining it under a flow of ammonia at temperatures ³900 oC.8,9 Their growth mechanism in the reactor remains unknown. In this report we prepare one-dimensional GaN nano- and microstructures by using a confined reactor made of alumina containing a Ga source and propose their growth mechanism.