Influence of precursor feeding rate on vapor–liquid–solid nanowire growth

The yield of Ge nanowires (NWs) synthesized using the vapor–liquid–solid (VLS) method was discovered to be highly sensitive to the rate of precursor feeding. When other parameters were fixed, fast filling of precursors yielded nearly 100% Ge NWs with regard to the growth seeds. By contrast, slow feeding produced nearly no or very low yield of Ge NWs. The dramatic difference was attributed to a layer of Ge coating on the surface of growth seeds. The coating formed at relatively low precursor pressures as a result of the imbalance in the VLS process. The results shed new light on the VLS mechanism in general.