Growth mechanism of stacked-cone and smooth-surface GaN nanowires

[[abstract]]Gallium nitride (GaN) nanowires were grown on uncoated or Ni-coated Si substrates by evaporation of Ga in NH3/Ar gas flow. A mixture of nanowires growing along [10 (1) over bar0] and [0001] was obtained, where the former showed smooth surfaces and the latter showed the stacked-cone morphology. The yield of the two types of nanowires was found to depend on the NH3 flow. The reduction of NH3 flow led to fewer stacked-cone nanowires. The growth mechanisms of the two types of GaN nanowires are discussed.[[fileno]]2010109010068[[department]]物理