RELAXATION AND RADIATIVE DECAY OF EXCITONS IN GAAS QUANTUM DOTS

Radiative and non-radiative exciton states of quantum dots with parabo lic lateral potentials are calculated in an effective-mass approximati on. Energy spectrum, radiative recombination rates and LA phonon scatt ering rates of the different excitons are discussed in their dependenc e on the lateral confinement potential. For sufficiently strong latera l potentials the relaxation of excitons by LA phonon emission becomes so weak that several excitonic levels should be observable in a photol uminescence experiment even at low excitation intensity. The theoretic al results are compared to microscopic photoluminescence data collecte d from a series of single GaAs quantum dots fabricated by laser induce d local interdiffusion.