Effect of Pd Reactant on One-Dimensional Growth of ZnO on Si Substrate by Thermal Evaporation Method

ZnO nanostructures were developed on a Si(100) substrate from the powder mixture of ZnO and x mol% Pd (ZP-x) as reactants using a thermal evaporation method. The effect of Pd on the growth characteristics of one-dimensional ZnO nanostructures was investigated. High temperature Xray diffraction patterns obviously revealed that Pd assisted the reduction of ZnO at temperatures higher than 1000 degrees C. Needle-like ZnO nanorod array, developed from ZP-x (x >= 2) mixture, was well aligned vertically on the Si substrate at 1100 degrees C while nano-crystalline ZnO layer was only obtained from pure ZnO powder. Thus, it is considered that Pd is responsible for the growth of ZnO nanorod on the Si substrate at 1100 degrees C by providing the Zn vapor for the Zn/ZnOx droplets with reducing ZnO in the reactant. The developed ZnO nanorod exhibited growth direction along [001] with defect-free high crystallinity. (C) 2011 The Japan Society of Applied Physics