SEGREGATION OF SI DELTA-DOPING IN GAAS-ALGAAS QUANTUM-WELLS AND THE CAUSE OF THE ASYMMETRY IN THE CURRENT-VOLTAGE CHARACTERISTICS OF INTERSUBBAND INFRARED DETECTORS

Dopant segregation in the well region of a multiple quantum well inter subband photodetector can cause an asymmetry in the observed forward a nd reverse current-voltage characteristics. We compensate for the segr egation by shifting the position of the Si delta doping in the well an d model the effect with good agreement for a range of shift values. Fo r samples grown at a substrate temperature of 605-degrees-C, we find t hat the observed behavior is best described by assuming that the Si de lta-doping profile smears in the growth direction resulting in an asym metric broadening of about 27 angstrom.