Droplet bulge effect on the formation of nanowire side facets

The process of lateral facet formation during vapor-liquid-solid nanowire growth is modeled to explain why the crystalline orientation of III-V nanowire side facets is affected by the droplet material. We find that the energy required for facet formation depends on the composition and shape of the liquid droplet. A droplet bulge effect that favors tilted nanofacets is identified: the lateral surface energy is reduced if the angle between droplet and facet is small. Detailed calculations demonstrate that this effect can promote otherwise unfavorable nanowire side facets when high-surface-energy droplet materials like Au are employed.