Interaction of localized electronic states with the conduction band: Band anticrossing in II-VI semiconductor ternaries

We report a strongly nonlinear pressure dependence of the band gaps and lar ge downward shifts of the conduction band edges as functions of composition in ZnSxTe1-x and ZnSeyTe(1-y) alloys. The dependencies are explained by an interaction between localized Al symmetry states of S or Se atoms and the extended states of the ZnTe matrix. These results, combined with previous s tudies of III-N-V materials define a new, broad class of semiconductor allo ys in which the introduction of highly electronegative atoms leads to drama tic modifications of the conduction band structure. The modifications are w ell described by the recently introduced band anticrossing model.