Growth of GaAs nanowires with various thickness of Au film

GaAs nanowires were grown by the metal organic chemical vapor deposition on the GaAs(111)B substrates via Vapor-Liquid-Solid mechanism with various Au film thickness. Experiment results indicated that thicker Au film results in larger diameters, more dispersed size distribution, and lower density of the nanowires. All NWs are straight from base to top, and no lateral growth occurs. The growth rate of nanowires slightly increases with Au film thickness. It indicates that the growth of GaAs NWs is mainly promoted by the catalyzed chemical reaction at the drop surface, the Au particles surface density could influence the growth rate, and contribution of diffusion from the adatom could be neglected.