The electronic structures of Mg_(y)Zn_(1-y)Te_(1-x)Se_(x) 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 ZnTe_(1-x)Se_(x) and ZnTe_(1-x)S_(x) 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 Mg_(y)Zn_(1-y)Te (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.
展开▼
