First-principles investigation of the structural, electronic and optical properties of Zn2NbN3

An ab initio study using density functional theory (DFT) is carried out to explore the structural, electronic, and opticalproperties of Zn2NbN3 compound. The structural properties of these compound are determined by using the approximation(GGA-PBE) as implemented in WIEN2k. The calculated lattice parameters of the Zn2NbN3 compound are found to bea = 9.91 °A, b = 5.81 °A and c = 5.44 °A . The calculated electronic band structure and density of states indicate that theZn2NbN3 compound is a wide gap semiconductor with a direct band gap of 2.5 eV. The different contributions of the electronicorbitals are discussed using the total and partial DOS with PBE and TB-mBJ approximations , which shows significantcontribution from the Nb-d and N-p. The optical properties such as dielectric function, refractive index, absorption coefficient,and extinction coefficient are calculated and discussed.