Characterization of MBE grown InGaAsGaAs strained-layer superlattices and single quantum wells by photoluminescence topography

A photoluminescence (PL) topography which allows the imaging of crystal defects of semiconductors nondestructively has been applied to characterize MBE grown In 0 . 1 Ga 0 . 9 As GaAs strained-layer superlattices (SLSs) and single quantum wells (SQWs). In SQWs dark line defects (DLDs) originate from misfit dislocations have been observed when well width is more than 40 monolayers. In SLSs cross stripes which are parallel and perpendicular to (011) have been observed. A propagation model of misfit dislocations is proposed by considering PL topograph patterns and surface morphology.