Quasi-two-dimensional excitons in (Zn,Cd)Se/ZnSe quantum wells: Reduced exciton–LO-phonon coupling due to confinement effects

Quasi-two-dimensional (2D) excitons in (Zn,Cd)Se/ZnSe quantum wells were investigated. We observed a confinement-induced enhancement of the exciton binding energy to a value greater than the longitudinal-optical (LO) -phonon energy. This unusual condition results in an effective reduction of the exciton–LO-phonon coupling. As a consequence, excitonic absorption features in this quantum-well system are well preserved to room temperature and beyond.