EXCITON-STATES IN GAAS ALGAAS BRAGG CONFINING STRUCTURES STUDIED BY RESONANT RAMAN-SCATTERING/

The LO phonon resonant Raman scattering is studied in GaAs/Al0.32Ga0.6 8As Bragg confining structures and in a similar (reference) superlatti ce. Strong resonances, with a large outgoing/incoming beam intensity r atio, are observed in the spectral range of the (e(B):hh(B)) Bragg con fined excitons as well as in the (e(l):hh(l)) exciton band. The resona nce profiles are analyzed in terms of a model of exciton scattering by interface and alloy potential fluctuations. The Bragg confined IS exc itons are found to be virtually two dimensional, while those of the su perlattice are intermediate between two and three dimensions.