Quantum lens in an external electric field: Anomalous photoluminescence behavior

Electric field (F) effects in self-assembled quantum dots with a lens geometry have been studied. The optical selection rules and the origin of the anomalous behavior of the photoluminescence lines with the applied field reported by Raymond et al. [Phys. Rev. B 58, R13415 (1998)] are analyzed in terms of the interband oscillator strength and lens symmetry. Also, an explicit analytical representation in the framework of the simple parabolic model for the electronic states as a function of F and lens parameter are given. The excitonic effect has been considered in the strongly confined regime when the excitonic Bohr radius is smaller than the dot dimensions. The influence of the lens geometry on the quantum Stark effect shows an asymmetric energy shift in the electron-hole transition.