Statistics of Nucleation and Growth of Single Monolayers in Nanowires: Towards a Deterministic Regime. Issue 5 (4th February 2022)

• Record Type: Journal Article
• Authors: Glas, Frank; Panciera, Federico; Harmand, Jean-Christophe
• Is Part Of: Physica status solidi. Volume 16:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-04
• Subjects: in situ transmission electron microscopy -- modeling -- monolayers -- nanowires -- nucleation -- statistics -- vapor–liquid–solid growth; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202100647
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : The vapor–liquid–solid growth of semiconductor nanowires proceeds via the sequential nucleation and extension of biatomic monolayers at the interface between the solid wire and a liquid catalyst nanodroplet. In the case of III–V compounds, this mother phase contains only a small concentration of the volatile group V atoms. The growth regime where there is not enough such atoms available in the liquid at nucleation to complete a whole monolayer is studied experimentally and theoretically. Each monolayer cycle then consists in the rapid formation of a partial monolayer, followed by a slower propagation stage and by a waiting time preceding the next nucleation. The propagation and waiting times of long sequences of monolayers are measured in situ in a transmission electron microscope at three growth temperatures, in a single GaAs nanowire. The process is modeled and the statistics of the characteristic times are computed numerically and analytically. At low temperature, the weakness of group V desorption from the liquid should lead to a constant total monolayer cycle time, despite the stochasticity of the nucleation events. The modeling of the experiments yields values of several crucial growth parameters and provides guidance for the growth of nanowires in a deterministic regime. Abstract : The statistics of nucleation and growth of individual biatomic monolayers in self‐catalyzed GaAs nanowires are investigated quantitatively by combining in situ transmission electron microscopy and modeling. When the catalyst droplet is very poor in As, a self‐regulated growth regime arises at relatively low growth temperature, despite the stochasticity of the nucleation events.