Atomic scale structure and optical emission of Alx Ga1−x As ∕ Ga As quantum wells

A combined study of the optical and structural properties of AlGaAs∕GaAs quantum wells is presented. Microphotoluminescence experiments, magnetomicrophotoluminescence, and atomically resolved cross-sectional scanning tunneling microscopy were performed on the same quantum well sample. Constant-current topographs with aluminum and/or gallium sensitivity are used to directly extract disorder potentials. Using these potentials, exciton absorption spectra, microphotoluminescence spectra, and diamagnetic shifts of individual exciton states are calculated in an envelope function approximation. Very good agreement between the theoretical and experimental results is found