Size effect on Ge nanowires growth kinetics by the vapor–liquid–solid mechanism

Germanium nanowires were grown on germanium (111) substrate by ultra high vacuum chemical vapor deposition, via the vapor–liquid–solid growth mechanism, using digermane as gaseous precursor and gold as catalyst. The results show that the nanowire length depends on the diameter catalyst, the smaller the nanowire radius, the slower the nanowires grow.In order to fit the experimental data, we have used a simple model based on the Gibbs–Thomson effect and adapted to our growth conditions. This model was found to perfectly account for the catalyst size dependence of the experimental growth kinetics of germanium nanowires from digermane. From that, a critical radius of 6 nm was derived.