Manifestation of interface anisotropy in CdTe quantum wells

Photoluminescence and polarized reflection spectra of quantum well structures with symmetric Cd${}_{0.9}$Zn${}_{0.1}$Te/CdTe/Cd${}_{0.9}$Zn${}_{0.1}$Te and asymmetric Cd${}_{0.9}$Zn${}_{0.1}$Te/CdTe/Cd${}_{0.4}$Mg${}_{0.6}$Te barriers were studied. The Stokes parameters of the reflected light from these structures were measured. In the structures with symmetric barriers, exciton resonances were found in the reflection spectra and were not present in the photoluminescence spectra. In structures with asymmetric barriers, in the region of exciton resonances, the phenomenon of light birefringence was detected, caused by a lower symmetry of the interfaces compared to the symmetry of bulk crystals. A discussion of both phenomena was given.