Band anticrossing effects in MgyZn1−yTe1−xSex alloys

Abstract

The electronic structures of MgyZn1−yTe1−xSex alloys were studied by optical absorption and photoluminescence techniques under applied hydrostatic pressure. In samples with both x and y≠0, the band gap exhibits a strongly nonlinear pressure dependence which is similar to the effects observed previously in ZnTe1−xSex and ZnTe1−xSx ternaries and that is well explained by the anticrossing interaction of the selenium localized electronic states with the conduction band of the matrix. In contrast, the pressure dependence of the band gap in MgyZn1−yTe (i.e., x=0) is not significantly changed in form from that of ZnTe; it is concluded that the effects of alloying MgTe with ZnTe can be well understood within the virtual crystal approximation.