  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.
