Spatially resolved photoluminescence in quantum wells with interface roughness: a theoretical description

We present a microscopic theoretical description of spatially resolved photoluminescence in GaAs quantum wells with interface roughness. The theory derives the kinetic equations using the excitonic wavefunctions obtained by solving numerically the effective Schr¨odinger equation for the excitonic centre of mass motion in the presence of disorder. The kinetic equations describe acoustic phonon scattering, radiative decay, and inhomogeneous sample excitation and/or light detection. The influence of disorder, temperature, and spatial resolution on the image formation is analysed with emphasis on the role of different interface textures. In particular, we consider two samples characterized by effective disorder potentials with different correlation lengths. Numerically calculated two-dimensional images agree with images from spatially resolved photoluminescence experiments and put forward the potential of the method for the understanding of near-field light emission from semiconductor quantum structures.