Relaxation of excitons in corrugated GaAs/AlAs superlattices

We report time-resolved spectroscopy on exciton luminescence in low-dimensional systems. The reduction of dimensionality from two in quantum wells to one in corrugated superlattices can completely change the initial relaxation process. In the one-dimensional system exciton-phonon scattering is, even at high exciton densities, faster than exciton-exciton scattering since the latter is reduced whereas the former is enhanced if the final state falls into the singularity in the density of one-dimensional states.