Size-dependent nucleation kinetics at nonplanar nanowire growth interfaces

In nanowire growth, kinetic processes at the growth interface can play an important role in governing wire compositions, morphologies, and growth rates. Molecular-dynamics simulations have been undertaken to probe such processes in a system featuring a solid-liquid interface shape characterized by a facet bounded by rough orientations. Simulated growth rates display a dependence on nanowire diameter consistent with a size-dependent barrier for facet nucleation. A theory for the interface mobility is developed, establishing a source for size-dependent growth rates that is an intrinsic feature of systems possessing growth interfaces with faceted and rough orientations.