Independent Control of Nucleation and Layer Growth in Nanowires

Abstract

Control of the crystallization process is central to developing novel\nmaterials with atomic precision to meet the demands of electronic and quantum\ntechnology applications. Semiconductor nanowires grown by the\nvapor-liquid-solid process are a promising material system in which the ability\nto form components with structure and composition not achievable in bulk is\nwell-established. Here we use in situ TEM imaging of GaAs nanowire growth to\nunderstand the processes by which the growth dynamics are connected to the\nexperimental parameters. We find that two sequential steps in the\ncrystallization process - nucleation and layer growth - can occur on similar\ntime scales and can be controlled independently using different growth\nparameters. Importantly, the layer growth process contributes significantly to\nthe growth time for all conditions, and will play a major role in determining\nmaterial properties. The results are understood through theoretical simulations\ncorrelating the growth dynamics, liquid droplet and experimental parameters.\n