Segregation of Si δ doping in GaAs-AlGaAs quantum wells and the cause of the asymmetry in the current-voltage characteristics of intersubband infrared detectors

Abstract

Dopant segregation in the well region of a multiple quantum well intersubband photodetector can cause an asymmetry in the observed forward and reverse current‐voltage characteristics. We compensate for the segregation by shifting the position of the Si δ doping in the well and model the effect with good agreement for a range of shift values. For samples grown at a substrate temperature of 605 °C, we find that the observed behavior is best described by assuming that the Si δ‐doping profile smears in the growth direction resulting in an asymmetric broadening of about 27 Å.