Band structure features, chemical bonding and optical properties of Zn3X2 (X = N, P, As) compounds

Abstract

In this study, we report the structural, electronic and optical behavior of Zn3X2 (X = N, P, As) compounds by using highly accurate all electrons full potential linearized augmented plane wave method within the density functional theory. The lattice parameters of cubic Zn3N2 (space group Ia3¯), Zn3P2 and Zn3As2 (space group Pn-3m) and tetragonal Zn3P2 and Zn3As2 (space group P42/nmc) are found in accordance to the experimentally measured values. Zn3N2 is direct bandgap semiconductor. Further, it is found that Zn3P2 and Zn3As2 are metallic in cubic, while semiconducting in the tetragonal symmetry. The optical properties like real and imaginary part of dielectric function, refractive indices, extinction coefficient, optical conductivity, absorption coefficient and reflectivity of these compounds are also calculated. The direct bandgap nature of the compounds shows their optical activity in the near infrared, visible and low frequency ultraviolet energy. Therefore, these materials are useful for the optoelectronic applications.