Growth of Pillarlike GaN Nanostructures

We have characterized the growth of GaN nanostructures on Si (111). Hexagonal faceted pillarlike GaN nanostructures (GaN nanopillars) were grown by hot wall epitaxy. The GaN nanopillars were self-assembled. Scanning electron microscopy and atomic force microscopy were used to characterize the samples. The typical diameter of the GaN nanopillars was 200 nm. It was found that GaN nanopillars are grown only on a low-temperature GaN island buffer layer. By changing the annealing temperature of the buffer layer, the density of the GaN nanopillars was controlled from 0.4×10 8 to 3.5×10 8 cm -2 .