Single-electron charging of a self-assembled II–VI quantum dot

We have studied single-electron injection into individual self-assembled CdSe/ZnSe quantum dots. Using nanostructured contacts to apply a vertical electric field, excess electrons are promoted to the single-quantum-dot ground state in a controlled fashion. Spatially-resolved photoluminescence spectroscopy is applied to demonstrate single-quantum-dot charging via the formation of single zero-dimensional charged excitons with a binding energy on the order of 10 meV.