Catalyst-free synthesis, morphology evolution and optical property of one-dimensional aluminum nitride nanostructure arrays

One-dimensional (1D) aluminum nitride (AlN) nanorod and nanocolumn arrays have been synthesized on graphite sheets, silicon and molybdenum (Mo) plates through a catalyst-free chemical vapor deposition (CVD) process employing AlCl3 and NH3 as sources. The as-prepared nanorods and nanocolumns vertically grow on the substrates with high alignment along [0 0 1] orientation of hexagonal AlN. Different AlN nanostructures, including hollow nanospheres, nanorod and nanocolumn arrays, roll-like hierarchical structures and nanoparticles, can be readily synthesized by adjusting the growth parameters. The morphological evolution of those nanostructures is addressed based on the vapor solid (VS) growth combined with the surface diffusion process. The photoluminescence and Raman scattering properties of the AlN nanorod and nanocolumn arrays are examined.