Insights on optical and charge density properties of semiconducting chalcopyrites ZnAP2 (A = Si, Ge, Sn) using modified Becke-Johnson potential – A first principles study

Abstract

The body centered tetragonal chalcopyrites ZnAP2 (A = Si, Ge, Sn) were explored by employing the full potential linearized augmented plane wave method towards the study of their unique electronic, optical and bonding properties. Our calculations show that the ZnSiP2, ZnGeP2, ZnSnP2 compounds are direct bandgap semiconductors. The spectral properties, such as total density of states and partial density of states are discussed in detail. The charge density and chemical bonding results predict the polar covalent nature of the Zn–P and A-P bonds. ZnGeP2 is predicted to have polar covalent nature less than the other. The variations of dielectric function, absorption coefficient, refractive index and optical conductivity indicate the influence of the Si, Ge and Sn. Possessing the direct band gap, high absorption capacity, low refractive index and high dielectric constant in the visible energy range imply that these chalcopyrites are suitable for optoelectronic applications.