Carrier dynamics and recombination processes of charged excitons in a GaAs/AlGaAs quantum well

We report a time-resolved photoluminescence study of neutral (X) and negati vely charged (X-) excitons in GaAs/AlGaAs quantum wells under resonant exci tation conditions. For X the temporal evolution of luminescence is dominate d by three decays attributed to resonant Rayleigh scattering, resonantly cr eated cold excitons, and an exciton population thermalized to the lattice t emperature. By contrast, for X- we find only one temperature-dependent deca y. We discuss these results in terms of the polariton description of radiat ive recombination. (C) 1999 Published by Elsevier Science B.V. All rights r eserved.