A. Garcia-cristobal et al., Electronic structure and phonon-assisted luminescence in self-assembled quantum dots, PHYS ST S-B, 215(1), 1999, pp. 331-336
We present photoluminescence (PL) measurements on an ensemble of InAs/GaAs
self-assembled quantum dots embedded in GaAs. We observe a transition from
an inhomogeneously broadened photoluminescence band under non-resonant exci
tation into up to five phonon-assisted bands under selective excitation. We
interpret the phonon-assisted PL as being indicative of an enhanced electr
on-phonon interaction. We also perform theoretical calculations of the sing
le-particle energy spectrum of self-assembled quantum dots, in the framewor
k of the single-band effective-mass approximation for electrons and using t
he Luttinger Hamiltonian for holes. Finally, by taking advantage of the com
puted wave functions we evaluate the Huang-Rhys parameter: We find an enhan
cement of the electron-phonon interaction that partially accounts for the e
xperimental re suits.