Optical detection of high-field domains in GaAs/AlAs superlattices

Abstract
We investigated the formation of high-field domains in undoped GaAs/AlAs superlattices under strong illumination. The photocurrent-voltage characteristics showed an oscillatory-like behavior which is attributed to the existence of high-field domains. We used photoluminescence (PL) spectroscopy to identify the existing domains as a function of electric field perpendicular to the layers. A total of five PL lines was observed and assigned to different domains through their Stark shift.