Lattice dynamics of II–VI mixed semiconductor ZnS1−xSex

Lattice dynamical properties of II–VI compounds having zinc-blende structure have been calculated by three-body shell model. This model incorporates the effect of the short-range repulsive interactions up to and including the second nearest neighbours, in addition to the long-range Coulombic interactions in the frame work of the rigid-shell model with both the ions are polarizable. The model involves in total eleven disposable parameters. Using the above proposed model the phonon dispersion relations for mixed II–VI semiconductor ZnS1−xSex are plotted. We find an overall good agreement with the experimental results. The application of the present model has been made to calculate the phonon dispersion relations of ZnS, ZnSe and mixed semiconductor ZnS1−xSex. The comparison of the theoretical results with the available experimental has been made along high symmetry directions. A reasonably good agreement is observed between theory and experiments.