A unified model of droplet epitaxy for compound semiconductor nanostructures: experiments and theory

TL;DR

This paper introduces a comprehensive model combining kinetic Monte Carlo simulations and experiments to understand and predict the formation of various nanostructures during droplet epitaxy of compound semiconductors.

Contribution

It presents a novel unified model that explicitly represents different atomic species and phases, accurately capturing experimental nanostructures and elucidating growth mechanisms.

Findings

Model reproduces experimental structures like islands and nanorings

Simulation predicts Ga/GaAs core-shell structures validated experimentally

Provides analytical insights into growth conditions and resulting nanostructures

Abstract

We present a unified model of compound semiconductor growth based on kinetic Monte Carlo simulations in tandem with new experimental results that can describe and predict the mechanisms for the formation of various types of nanostructures observed during droplet epitaxy. The crucial features of the model include the explicit and independent representation of atoms with different species and the ability to treat solid and liquid phases independently. Using this model, we examine nanostructural evolution in droplet epitaxy. The model faithfully captures several of the experimentally observed structures, including compact islands and nanorings. Moreover, simulations show the presence of Ga/GaAs core-shell structures that we validate experimentally. A fully analytical model of droplet epitaxy that explains the relationship between growth conditions and the resulting nanostructures is presented, yielding key insight into the mechanisms of droplet epitaxy.