Electrodeposition of metal on Gallium Arsenide nanowires

In the majority of reported studies, metal contacts to semiconductor nanowires (NWs) have been fabricated using high-resolution electron-beam lithography with metal evaporation. In our study, copper (Cu) or iron (Fe) electrical contacts to as-grown gallium arsenide (GaAs) nanowires have been fabricated via electrodeposition. For nominally undoped GaAs nanowires, we find that Cu or Fe has a preference for nucleation and growth on the gold catalyst avoiding the sidewalls. For carbon-doped nanowires with higher conductivity, Cu nucleation and growth began to occur on the sidewalls as well as on the gold catalyst. COMSOL finite element analysis, carried out to simulate the experimental results, was used to discuss the growth mechanism in terms of nanowire sample surface, conductivity and morphology.