Ex‐situ control of fine‐structure splitting and excitonic binding energies in single InAs/GaAs quantum dots

A systematic study of the impact of annealing on the electronic properties of single InAs/GaAs quantum dots (QDs) is presented. We are able to record single QD cathodoluminescence spectra and trace the evolution of one and the same QD over several steps of annealing. A systematic reduction of the excitonic fine‐structure splitting is reported. In addition the binding energies of different excitonic complexes change dramatically. The results are interpreted in terms of a change of electron and hole wavefunction shape and mutual position.