Effect of CVD Synthesis Parameters on the Growth of Catalyst-Free ZnO NRs

The main development of ZnO nanorods (NRs) is focused on the gold catalyst and heteroepitaxial approach.However, the presence of Au may generate undesired deep level traps in the ZnO bandgap, which could be very harmful to the performance of transistors. The objective of this study is to synthesize ZnO NRs via homoepitaxial growth without using foreign catalyst by Chemical Vapour Deposition (CVD) technique. The growth of catalyst-free ZnO NWs at different CVD synthesis parameters such as amount of Zn powder, substrate location and synthesis duration on the catalyst-free ZnO NRs were studied systematically. The effect of these parameters on the size and areal density of ZnO NRs provided a better understanding on the growth mechanism of NRs via the Vapour-Solid (VS) mechanism.