Thermodynamic Stability of Gold-Assisted InAs Nanowire Growth

Growth of III–V semiconductor nanowires is generally assisted by a liquid particle in order to get a highly anisotropic crystallization. The thermodynamic stability of the particle is therefore of importance for control and understanding of the nanowire growth process. In this report we explore the particle stability by manipulating its properties, specifically its surface tension and volume, by accumulating indium in the particle during nanowire growth. We demonstrate a droplet displacement, from the top to one of the nanowire side facets, when exceeding the stability limit for a gold particle wetting an [0001̅]-oriented InAs nanowire. This particle displacement is attributed to a lowered surface tension and a truncation of the top facet. In addition, our results indicate reversibility of the displacement, showing that the (1̅1̅1̅/0001̅) facet is the most favorable for a droplet to wet during common growth conditions. The stability condition for InAs growth is determined experimentally, and the understanding developed can easily be applied to other III–V nanowires