An insight of Mg doped ZnO thin films: A comparative experimental and first-principle investigations

The aim of this work was to study the structural, electronic and optical properties of Zn_1-xMg_xO (x = 0, 0.1, 0.3). All theoretical calculations were performed using density functional theory (DFT) and employing the plane-wave pseudopotential method. It was found that the bandgap increased progressively with doping of Mg impurity in pure ZnO thin films. Pure and Mg-doped ZnO thin films (x = 0, 0.1, 0.3) were fabricated using a sol-gel spin coating method and structural characteristics were studied by X-ray diffraction (XRD). The XRD measurements indicated that Mg doping increases the grain size. The products were crystalline with a hexagonal wurtzite phase and the predominant plane was appeared as (001). The optical properties were calculated using ultraviolet (UV) absorption spectra. The blueshift in UV spectra with an increase of Mg concentration confirmed a reasonable increase in the bandgap of ZnO thin films. The bandgap of ZnO thin films was shown to increase progressively with successive increase of Mg concentration in both cases (experimental as well as DFT calculations). Defects in the crystalline structure and their behavior in ZnO thin films were also explored for possible applications in the electronic and optoelectronic industry.