Many-body effects in the luminescence of highly excited indirect superlattices

Experimental and theoretical investigations of the optical-excitation-dependent spatially indirect photoluminescence of GaAs/AlAs type II superlattices are reported. Simultaneous blue and red shifts of the indirect photoluminescence peaks are observed and analyzed, using many-body theory. The relevant microscopic mechanisms are exchange and correlation effects in the excited electron and hole plasmas as well as energy renormalizations due to the optically induced space-charge potential, the latter being the dominant effect. Comparison of theory and experiment allows us to extract the individual renormalization effects in the electron and hole plasmas.