Tuning of Vertical and Lateral Correlations in Self-Organized $\mathrm{PbSe}/{\mathrm{Pb}}_{1-\mathit{x}}{\mathrm{Eu}}_{\mathit{x}}\mathrm{Te}$ Quantum Dot Superlattices

The tuning of lateral and vertical correlations in self-organized $\mathrm{PbSe}/\mathrm{Pb}{}_{1-x}\mathrm{Eu}{}_x\mathrm{Te}$ quantum dot superlattices by changes in the spacer thicknesses is demonstrated and shown to be due to finite size effects in the dot-dot interactions. As a consequence, different dot arrangements such as vertically aligned dot columns or fcc stacking are obtained for a single material system without changes in growth conditions. The different dot superstructures are shown to exhibit a different scaling behavior of the lateral versus vertical dot separation, as well as a different evolution of dot sizes and shapes.