Resonant Rayleigh scattering by Wannier excitons in a two-dimensional disordered potential

Resonant Rayleigh scattering (RRS) in semiconductors is due to imperfections breaking the symmetry of translational invariance of the crystal: impurities, defects or interfaces. The RRS observed from semiconductor quantum wells (QWs) is mainly due to fluctuations in the lateral two-dimensional potential energy confining charge carriers and excitons. Time resolving the RRS allows us to extract the statistical properties of the disorder potential, including a certain degree of spatial correlation. Furthermore, the temporal coherence of RRS has been demonstrated by interferometric experiments with a single speckle, allowing us to discriminate RRS very clearly from incoherent fluorescence. This lively ongoing field of research has brought about generic fundamental notions readily applicable to spectroscopy of other semiconductor nanostructures or possibly inorganic crystals, which are worth compiling. This paper aims at reviewing a large fraction of the experiments carried out on GaAs QWs, which have contributed significantly to the understanding of the static and dynamic properties of RRS.