Theoretical Modeling of Indium Adatoms on Reconstructed GaAs(001) and AlAs(001) Surfaces

GaAs/AlAs(001) (2 × 4) is one of the most optimal substrates for optoelectronic and nanophotonic applications. Droplet epitaxy allows high-quality quantum dot (QD) arrays with the desired properties to be obtained, but the detailed mechanism of deposition and subsequent epitaxial growth is still questionable. In this paper, the growth mechanism of indium QDs on various GaAs/AlAs(001) surfaces is studied within calculations of density functional theory. Full geometry optimization, in which the coordinates of substrate atoms can be altered under adatom impact, is shown to be a straightforward technique for the simulation of adsorption processes. The obtained results are in good agreement with conventional methods and well-known findings. The proposed approach could become standard practice and extend the understanding of droplet epitaxy.