DFT studies on the structural, electronic, and optical properties of Na2ZnP2O7 compound

Abstract

First principles density functional theory calculations were applied to determine the structural, electronic, elastic, and optical properties of disodium zinc diphosphate (Na2ZnP2O7) compound. The calculated lattice parameters of the Na2ZnP2O7 compound are found to be a = 7.75 Å and c = 10.20 Å, which are in reasonable agreement with available experimental data. From the calculated energetics and elastic properties, the formation of the Na2ZnP2O7 compound is energetically favorable and elastically stable. The calculated electronic band structure and density of states indicate that the Na2ZnP2O7 compound is a wide gap semiconductor with a direct band gap of 4.95 eV. Such a wide bandgap energy has a broad tunable spectral range, making this compound suitable for absorbing or emitting ultraviolet (UV) light. The different contributions of the electronic orbitals are discussed using the partial density of states, which shows significant contribution from the Zn atom with minor contribution from the Na, P and O atoms. The optical properties such as dielectric function, optical conductivity, refractive index, absorption coefficient, reflectivity, and electron energy loss are calculated and discussed.