RELAXATION AND RADIATIVE DECAY OF EXCITONS IN GAAS QUANTUM DOTS

Radiative and non-radiative exciton states of quantum dots with parabolic lateral potentials are calculated in an effective-mass approximation. Energy spectrum, radiative recombination rates and LA phonon scattering rates of the different excitons are discussed in their dependence on the lateral confinement potential. For sufficiently strong lateral potentials the relaxation of excitons by LA phonon emission becomes so weak that several excitonic levels should be observable in a photoluminescence experiment even at low excitation intensity. The theoretical results are compared to microscopic photoluminescence data collected from a series of single GaAs quantum dots fabricated by laser induced local interdiffusion.