Behavior of GaN nanoneedles grown by using hydride vapor phase epitaxy for different growth times

Abstract

Gallium nitride (GaN) nanoneedles were synthesized by using the hydride vapor phase epitaxy method at various growth temperatures and times under a HCl:NH3 flow ratio of 1:38. The morphology of GaN nanostructures varied according to the growth temperatures, and nanoneedles were formed at 640°C temperature zone. Further, their heights and diameters increased with increasing growth time whereas the stems of the nanoneedles coalesced. X-ray diffraction patterns showed that the GaN nanoneedles were orientated along the [0001] direction and underwent biaxial compressive stress. Also, the Raman spectra exhibited the smallest compressive strain in the sample grown for 60 min compared to the other samples.