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

Abstract

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 X-ray diffraction patterns obviously revealed that Pd assisted the reduction of ZnO at temperatures higher than 1000 °C. Needle-like ZnO nanorod array, developed from ZP-x (x≥2) mixture, was well aligned vertically on the Si substrate at 1100 °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 °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.