The controllable growth of GaN nanostructures with various morphologies

The authors successfully fabricated GaN nanostructures with various morphologies by precisely tuning the key parameters of chemical vapor deposition, such as growth time, temperature and reaction gas flow. The nanostructures with manifold morphologies including nanowires, micro/nanocones, nanotowers, tower-like nanowires and stacked-cone nanowires can be selectively fabricated according to different experimental details. Based on the evolution of the nanostructures, the initial growth is based on VLS mechanism, while VS mechanism progressively dominates crystal growth as growth time increases or temperature rises. Ga flow has great impact on the morphology of the nanostructures. Formation processes of the nanostructures are explained by direct impingement and surface diffusion model of the adatoms. These nanostructures have potential applications in the optoelectronic and microelectronic devices.