Role of surrounding oxygen on oxide nanowire growth

The ability to control oxide nanowires via vapor-liquid-solid (VLS) mechanism remains an important challenge to explore various applications of oxide nanowires. Here we demonstrate the crucial roles of surrounding oxygen on VLS grown SnO₂ nanowires. When the partial pressure of surrounding oxygen is relatively low, the oxygen mainly acts as an oxygen source, promoting VLS growth. While for relatively high oxygen partial pressures, vapor-solid (VS) growth emerges, suppressing nanowire growth. The findings as to the roles of surrounding oxygen on the inherent competition between VLS and VS growths are in principle rather universal for VLS grown nanowires of various oxides.