Pressure-dependent dynamical properties of Zn-based II-VI semiconductors

The effect of pressure on optical phonons and polaron properties in ZnS, ZnSe, and ZnTe II-VI compound semiconductors has been investigated. The calculations are performed in the framework of ab initio pseudopotential approach based on the density functional perturbation theory. At zero pressure, a reasonable degree of agreement is generally found between our results and data available in the literature. It is found that when pressure is increased the phonon modes at Gamma in the Brillouin zone are shifted towards high energies. The pressure dependence of features such as Frohlich coupling parameter, the Debye temperature of the longitudinal optical phonon frequency and the polaron effective mass showed that the polaron properties are sensitive to the pressure effect. (C) 2012 Elsevier B.V. All rights reserved.