First-principles calculations on vibrational and dielectric properties of chalcopyriteCuGaS2

Abstract

We have performed a first-principles study of structural, dynamical and dielectricproperties of chalcopyrite semiconductor CuGaS2. The calculations havebeen carried out within the local density functional approximation usingnorm-conserving pseudopotentials and a plane-wave basis. Born effective chargetensors, dielectric permittivity tensors, the phonon frequencies at the Brillouinzone centre and mode oscillator strengths are calculated using densityfunctional perturbation theory. The calculated properties help resolvethe source of some of the discrepancies in the experimental literature.