On the physical understanding of quantum rings self-assembly upon droplet epitaxy

Abstract

A quantitatively kinetic model has been established to address the quantum rings (QRs) self-assembly upon the droplet epitaxy. Taking the GaAs system as an example, we found that the diffusion of Ga atoms away from the droplet and the trapping of As atoms play crucial roles in the final shape formation of GaAs nanostructures. By calculating the amounts of the produced GaAs in each point, we performed the shape evolution of GaAs nanostructures during the crystallization process. The proposed kinetic theory nicely elucidates the physical mechanisms of the self-assembly of GaAs nanostructures including the single and double QRs and the holed nanostructure upon the droplet epitaxy.