Quasi-aligned single-crystalline GaN nanowire arrays

Quasi-aligned GaN nanowire arrays have been fabricated via a thermal evaporation of the starting reactants Ga2O3/GaN. The GaN nanowires have uniform diameters of similar to 300 nm, lengths up to tens of micrometers and possess a sharp six-fold symmetrical pyramidlike tip. High-resolution transmission electron microscopy (TEM) analysis indicated that majority of GaN nanowires have a preferential growth direction along the [0001] direction. Room-temperature field-emission measurement showed that the as-synthesized GaN nanowire arrays have a lower turn-on field of 7.0 V/mu m. It is believed that both the sharp tips and rough surface of GaN nanowires contribute to the excellent electron emission behavior. (C) 2005 American Institute of Physics.