Enhanced Synthesis Method to Prepare Crystalline GaAs Nanowires with High Growth Yield

Ning Han1,  Fengyun Wang2,  Alvin T. Hui2,  Jared J. Hou2,  Guangcun Shan2,  Fei Xiu2,  Tak Fu. Hung2,  Johnny C. Ho1

1Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Ave., H.K. SAR, China., 2

Abstract

Solid-source chemical vapor deposition method is developed for the synthesis of crystalline GaAs NWs with high growth yield using Ni thin film as catalysts on amorphous SiO2/Si substrates. The NW growth parameters are optimized at the source temperature of 900 deg C, substrate temperature of 600 deg C and H2 flow rate of 100 sccm for 30 min. The obtained NWs have a narrow distribution of diameters (21.0 ± 4.0 nm), with the length exceeding 10 μm. The NWs are grown along different crystallographic directions with low defect densities observed.