Synthesis, Microstructure, And Cathodoluminescence Of [0001]-Oriented Gan Nanorods Grown On Conductive Graphite Substrate

One-dimensional GaN nanorods with corrugated morphology have been synthesized on graphite substrate without the assistance of any metal catalyst through a feasible thermal evaporation process. The morphologies and microstructures of GaN nanorods were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The results from HRTEM analysis indicate that the GaN nanorods are well-crystallized and exhibit a preferential orientation along the [0001] direction with Ga3+-terminated (<10(1)over bar1> and N3--terminated (10 (11) over bar) as side facets, finally leading to the corrugated morphology surface. The stabilization of the electrostatic surface energy of [10 (1) over bar1) polar surface in a wurtzite-type hexagonal structure plays a key role in the formation of GaN nanorods with corrugated morphology. Room-temperature cathodolurninescence (CL) measurements show a near-band-edge emission (NBE) in the ultraviolet range and a broad deep level emission (DLE) in the visible range. The crystallography and the optical emissions of GaN nanorods are discussed.