Fabrication and photoluminescence of ordered GaN nanowire arrays

Large-scale of crystalline GaN nanowires (diameter similar to 50 nm) have b een fabricated through chemical-vapor deposition in the nanochannels of the anodic alumina template. X-ray diffraction and selected area electron diff raction pattern investigations indicate that the nanowires are single cryst al with hexagonal wurtzite structure. A typical scanning electron microscop y image and the energy dispersive x-ray spectroscopy results indicate that indium nanoparticles only act as catalyst in GaN nanowires growth. At room temperature, photoluminescence spectrum of the GaN nanowire arrays shows a visible broadband with three peaks, which are located at about 363, 442, an d 544 nm. The light emission may be attributed to GaN band-edge emission, t he existence of defects or surface states, and the interaction between the ordered GaN nanowires and anodic alumina membrane. The growth mechanism of crystalline GaN nanowires is discussed. The method makes it possible to syn thesize other nitride nanowire arrays. (C) 2001 American Institute of Physi cs.