ABSTRACT
Figure 4. Polarized photoconductivity signal around 1 eV vs analyzer angle for GaAsSb/GaAs MQWs. The solid curve is a cos2 () fit.
The transition of the continuous energy states can be attributed to interface imperfections. For example, there may exist wrong bonds at interfaces (e.g., Sb-Ga and As-Ga bonds or As-Ga and As-Ga in GaAsSb/GaAs heterostructures), which are different from the bonds in constituent layers. These wrong bonds can be considered as a kind of localized distortion, i.e., a certain "defectlike" impurity, with respect to the host structure. Thus, polarized PC spectra provide a very good opportunity to search the effects of microscopic interface defects in semiconductor heterstructures.
