Growth And Characterization Of Gan Nanowires On Si Substrate Using Ni Catalyst In A Chemical Vapor Deposition Reactor

GaN nanowires were successfully grown on Ni-coated Si substrate by the direct reaction of gallium metal with ammonia gas in a home-made vertical tubular chemical vapor deposition reactor and characterized using field emission scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, and photoluminescence (PL) measurements. The growth of GaN nanowires was uniformly observed on the Si substrate surface when the distance between Ga and the Si substrate was in the range 0-4 cm. The diameter of the nanowires was about 25 rim, but the length was up to several micrometers. The clear lattice fringes in high-resolution TEM images revealed. the growth of high-quality hexagonal single-crystal nanowires. PL of the GaN nanowires showed a strong band edge emission at an energy of similar to3.4 eV with negligible deep-level yellow emission. The catalytic growth mechanism of the GaN nanowires is discussed on the basis of the experimental results.