Simulation and Modeling of Structural Stability, Electronic Structure and Optical Properties of ZnO

Abstract

We propose a generalized gradient approximation simple and effective Engel-Vosko (GGA-EV) to calculate the structural, electronic, optical properties of ZnO phases, namely, wurtzite, zinc-blende structures using an implementation of the FP method (L) APW in the framework of the density functional theory (DFT). For Choosing a good exchange and correlation potential for effective treatment of the excited state properties such as electronic band structure is necessary density functional. To validate our approach, we compare the results to those obtained using the parameterized generalized gradient approximation of Perdew et al. (GGA-PBE). We calculated the band structure, density of states, dielectric function, reflectivity, refraction index and absorption coefficient. GGA-EV yielded a wider valence band and narrower d-band in comparison to GGA-PBE. Thus an improved the energy band gap that has been caused by repulsion between the states of Zn-d and O-p states which resulted a large separation by GGA-EV. Our calculations show that the edges of the optical absorption, refraction index and reflectivity for GGA-EV are better in comparison to GGA-PBE.