Liquid droplet dynamics and complex morphologies in vapor–liquid–solid nanowire growth

The morphology of semiconducting nanowires, including kinked and branched wires, must be controlled in order to produce functional devices. Here, we describe some of the experimental and theoretical work involving complex morphologies of Au-catalyzed Si nanowires grown using the vapor–liquid–solid technique. Although there is a broad parameter space to explore, experiments have highlighted the importance of the precursor and impurity partial pressures on kinking behavior. Theoretical and modeling work has indicated that the stability of and transitions in droplet configuration are important for growth direction changes that can lead to complex morphologies. We describe recent phase-field simulations of nanowire growth that address the dynamics of liquid droplets during vapor–liquid–solid growth, as well as the implications of these results for the formation of wires with complex morphology.