Controlling the Growth Mechanism of ZnO Nanowires by Selecting Catalysts

Abstract

The effect of catalysts on ZnO nanowire growth was investigated by comparing the performances of Au, Pt, and Ag nanoparticles. Additional control of growth was achieved by implementing a substrate temperature of either 800 °C with a ZnO/graphite powder source or 500 °C with a Zn powder source. At 800 °C, the vapor−liquid−solid mechanism plays a very important role when the Au and Pt nanoparticles are in the liquid phase. On the other hand, nanowires can also be grown on solid nanoparticles, that is, oxidized Ag at 800 °C and nanoscale cracks, that is, Pt at 500 °C, where, the vapor−solid is the only possible mechanism. At 500 °C, the vapor−liquid mechanism still dominates even though Au and Ag appear to be liquid, which is a result of high Zn vapor pressure.