Structural and optical properties of ZnO nanowires synthesized from ball-milled ZnO powders

ZnO nanowires were synthesized at 1380degreesC from ball-milled ZnO powders by a thermal evaporation procedure with argon carrier gas without any catalysts. Scanning electron microscopy revealed that the typical diameter and length of the ZnO nanowires are in the uniform ranges of 15 to 40 nm and 10 to 70 mum, respectively. Transmission electron microscopy results revealed that the ZnO nanowires are single crystalline with the growth direction perpendicular to the (110) lattice planes. In photoluminescence spectra taken at 8 and 300 K, the peak energies of near band-edge (NBE) emission peaks for the ZnO nanowires are lower by about 40 meV than for ZnO bulk, and the NBE emission from the nanowires is much broader than that for the bulk.