Three-dimensional finite-element simulations of the self-organized growth of quantum dot superlattices

Controlling the self-organized growth of quantum dot superlattices to achieve perfect dot arrays has been studied through three-dimensional computer simulations. A growth window has been identified in which the self-organized quantum dots are arranged in a body-centered tetragonal superlattice with a fixed dot spacing irrespective of growth rates. However, the size of the quantum dots can be tuned through the change of growth rate. Surprisingly, the ordering of the self-organized quantum dot superlattices is controlled by the ordering of strain energy density maxima, which is in contrast with the previous understanding that the ordering of the self-organized quantum dot superlattice is controlled by the ordering of the strain energy density minima. This provides a guideline for the fabrication of quantum dot superlattices.