Effect of doped substrates on the growth of GaAs nanowires via metal organic chemical vapor deposition

Abstract

Vertical GaAs nanowires were grown on different doped substrates via Metal Organic Chemical Vapor Deposition by catalyst assisted vapor-liquid-solid mechanism. It is found that both n and p type doped substrates affect catalyst distribution during the formation of alloy catalysts. The catalyst density decreases with an increase in the doping concentration of the substrates. In the growth of GaAs nanowires, the growth rate, which is mostly determined by the atoms diffusion from the pyrolysis of precursors on the surface of nanowires and substrates, is proportional to the catalyst densities. Moreover, the structures of as-grown nanowires are all pure zinc blende without any defects. These results will be valuable for the applications of nanowire-based optical and electrical devices.