Study of Phonon Dynamics of Calcium Chalcogenides from First Principles Method

The calcium chalcogenides belong to an important class of semiconductor materials. It comprises a large band gap which enables its use in applications of luminescent devices, so they are of technological and scientific interest. These compounds are found in NaCl (B1) and CsCl (B2) crystallographic phase. In the current work, structural properties of calcium chalcogenides have been studied to understand their phase stability. Here, these properties are computed by applying the plane wave pseudopotential method employing a generalized gradient approximation (GGA) of the density functional theory (DFT). In addition to this an effort is also made to plot the phonon density of state (PDOS) and phonon dispersion spectra of this compound to understand the phonon behavior and are compared with other calculated results.