Synthesis of GaN nanochestnuts by hydride vapour phase epitaxy

GaN nanochestnuts with numerous nanorods and nanoneedles were synthesized on AlN/Si(111) substrate using hydride vapour phase epitaxy (HVPE) method under constant N2 carrier gas flow rate. The formation process of nanochestnuts was systematically investigated and discussed on the basis of the experimental results. The nanochestnuts were analyzed by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and cathodoluminescence (CL). GaN nanochestnuts were revealed as the composition of core, circular stacking layers, and surrounded with nanorods or nanoneedles on all sides. The resultant nanochestnuts may be a promising structure for omnidirectional nano device applications in the future.