Synthesis of one-dimensional GaN nanostructures and GaN/CNT/SI/silicate nanocables by metalorganic chemical vapor deposition

One-dimensional GaN nanostructures and GaN/CNT/Si/silicate nanocables have been synthesized by metalorganic chemical vapor deposition. Nanotubes were formed at 600°C, whereas nanowires were grown at 800-1000°C manly through vapor-liquid-solid mechanism. At 1100°C, stacked hexagonal pyramid structure was grown. The growth of the complex nanostructure was inferred to be governed by both surface diffusion and bulk diffusion. The nanotubes were characterized to be of single crystalline wurtzite phase and were grown along the [110]GaN direction. It is proposed that the formation of Ga-Au eutectic phase, Ga supersaturation and precipitation, as well as a limited nitridation efficiency at the low temperature led to the peculiar nanostructures. For the synthesis of GaN/CNT/Si/silicate nanocables, carbon nanotubes were used as the templates. The nanostructures include a core of GaN nanodots and nanorods inside carbon nanotubes sheathed by amorphous Si and silicate nanotubes. The method can efficiently control the diameter of GaN nanostructure in molecular-scale (2-10 nm).