Independent control of nucleation and layer growth in nanowires

TL;DR

This study demonstrates independent control over nucleation and layer growth in GaAs nanowires during vapor-liquid-solid synthesis, revealing their distinct dynamics and impact on material properties through in situ TEM imaging and theoretical modeling.

Contribution

It introduces a method to independently manipulate nucleation and layer growth in nanowire fabrication, enhancing control over nanostructure properties.

Findings

Nucleation and layer growth occur on similar time scales.

Layer growth significantly influences overall growth time.

Growth dynamics can be controlled independently using different parameters.

Abstract

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