Suppression of Raman Scattering by Interface Phonons in Quantum Wells under High Photoexcitation

摘要

This reprint reports on the power-density dependence of resonant Raman scattering by interface phonons in GaAs-Al(x)Ga(1-x)As quantum wells. Strong photoexcitation leads to suppression of the nominally forbidden (defect-induced) scattering. The magnitude of the quenching is largest for laser energies in the vicinity of outgoing resonances. Alternative mechanisms which partially account for the experimental findings are discussed. We consider in particular the role of ionized impurities and effects due to screening by photoexcited carriers. (jhd)