Stabilization of the Morphology and Crystal Phase in Ensembles of Self‐Catalyzed GaAs Nanowires

Abstract

Recent experimental data reveal the two stable contact angles of gallium droplets promoting the vapor–liquid–solid growth of GaAs nanowires, around 90° and 130°, with the critical angle of developing the truncated growth interface being smaller, but very close to 130°. Herein, a model is presented for the time evolution of the nanowire radii and preferred crystal structures in large ensembles of self‐catalyzed GaAs nanowires. The model qualitatively explains earlier experimental observations and even contradictory results. It is shown that all nanowires stabilize to a stationary radius and pure zincblende phase within the optimal range of V/III flux ratios. Lower V/III flux ratios yield pure zincblende phase without any radius stabilization, whereas higher V/III ratios lead to a limited focusing of the radius, polytypism, or even pure wurtzite phase of GaAs nanowires.