First-principles on The Electron Structure and Optical Properties of The Mg-doped CdSe System

The electron structures and optical properties of the wurtzite Cd1-xMgxSe systems are calculated by the first-principles ultra-soft pseudo-potential plane wave approach based on the density functional theory.The obtained results indicate that the top of valence band is fundamentally determined by the Se4p electrons and nearly unchanged;the bottom of conduction band is determined by Se4s electrons and Cd5s electrons and it is removed to higher energy direction with the increase of Mg concentration,thus the band gap is broadened.The peaks in the imaginary part of dielectric function and the peaks in the real part of refractive index are found to have blue-shifts as Mg concentration increases.Our results are agreement with the experimental results.