Exciton dynamics in a GaAs quantum well

Time-resolved luminescence measurements in a 27-nm GaAs quantum well show that the initial temperature of the photocreated exciton distribution is determined by the excess energy of the excitation photon. Light-hole excitons lying in the band gap transfer to heavy-hole exciton states by density-dependent exciton-exciton scattering. For excitation close to the band edge, excitons cool only via LA-phonon emission. The time-resolved luminescence profile is modeled by evaluating the LA-phonon energy-loss rate.