Role of elastic anisotropy in the vertical alignment of In(Ga)As quantum dot superlattices

Abstract

This letter shows the effect of the elastic anisotropic strain field in the vertical stacking for multilayer In(Ga)As∕GaAs quantum dot (QD) structures grown by molecular beam epitaxy. This effect explains the QD enlargement in vertical correlated stacking and the possibility to obtain QD vertical anticorrelated stacking. The anticorrelation configuration in these structures is dependent not only on the QD size and on the interlayer spacing but also on the QD density. With appropriate choice of these structural parameters, a QD body centered cubic arrangement can be produced with a narrower size distribution which is in marked contrast to commonly observed vertically correlated QDs.