Study on Electronic and Optical Properties of Al-Doped ZnS from Density Function Theory

Using ab-initio ultrasoft pseudopotential plane wave approximation method based on density functional theory (DFT), a systematic investigation on electronic and optical properties of ZnS with and without Al-doping has been performed. Calculation results show that Al-doping narrows the band gap of ZnS systems and Al-doped ZnS system changes from semiconductor into metal through the Mott transition. Moreover, with Al-doping increasing, the increase of absorption coefficient and redshift of absorption spectra are obtained. Absorption spectra of pure ZnS and Al-doped ZnS are in good agreement with the experimental results.