Analytic many-body potential for InAs/GaAs surfaces and nanostructures: Formation energy of InAs quantum dots

摘要

A parametrization of the Abell–Tersoff potential for In, Ga, As, InAs, and GaAs is presented by using both experimental data and results from density-functional calculations as input. This parametrization is optimized for the description of structural and elastic properties of bulk In, Ga, As, InAs, and GaAs, as well as for the structure and energy of several reconstructed low-index GaAs and InAs surfaces. We demonstrate the transferability to GaAs and InAs high-index surfaces and compare the results to those obtained with previously published parametrizations. Furthermore, we demonstrate the applicability to epitaxial InAs/GaAs films by comparing the Poisson ratio and elastic energy for biaxial strain, as obtained numerically with our potential and analytically from continuum-elasticity theory. Limitations for the description of point defects and surface diffusion are pointed out. This parametrization enables us to perform atomically detailed studies of InAs/GaAs heterostructures. The formation energy of InAs quantum dots on GaAs(001) obtained from our atomistic approach is in good agreement with previous results from a hybrid approach.