Résumé
High intensity photoluminescence data on GaAs/AlAs superlattices and multi quantum wells of type II at low temperature are reported. The variation with density of the renormalized band gap reveals the competition between the Hartree energy and the many-body effects (mainly exchange). Preliminary analysis for a lot of samples with widely different periods provides a satisfactory fit with Hartree-Fock model. The kinetics of luminescence and total decay in the electron-hole plasma regime is measured. In some samples, a phase transition was observed which is tentatively interpreted in term of electron-hole liquid condensation.