Ab-initio calculations of structural, electronic, and dielectric properties of ZnO

In the present study the results of an ab-initio theoretical study of the electronic structural and optical properties corrected by scissor of zinc oxide in wurtzite phase using an implementation of the FP method(L) APW in the framework of the density functional theory (DFT); the potential for exchange and correlation is treated within the generalized gradient approximation of the Engel-Vosko GGA-EV for the calculation of electronic and optical properties of ZnO. To validate our approach, we compare the results of electronic properties with those obtained using the generalized gradient approximation parameterized by Perdew, Burk and Emzerhop Perdew (GGA-PBE). The frequency dependent complex dielectric function ε (ω) is calculated as well as the reflectivity and absorption coefficient. Our calculations show that the optical absorption edge to ε₂^xx (ω) and ε₂^zz (ω) are located around 3.19 eV. The structural properties, the band structure and density of states are present. The lattice constants of ZnO calculated in this study are in agreement with the experimental values and the band gap obtained by the GGA-EV yielded a broad and narrow valence band relative to GGA-PBE. Moreover, EV-GGA yielded a large separation between the states d of Zn and states p of O, thereby reducing the repulsion p-d and therefore improved the energy band.