Synthesis and characteristics of Mg doped ZnO thin films: Experimental and ab-initio study

Abstract

Structural and physical properties of Mg doped zinc oxide (MZO) thin films have been investigated. The samples have been synthesized using a simple spray pyrolysis technique. The hexagonal Wurtzite structured ZnO thin films were confirmed by X-ray diffraction (XRD). The morphology of the thin films was characterized by atomic force microscopy (AFM). The optical properties were studied in details by using ultraviolet–visible (UV–Vis) spectrophotometry and Hall Effect measurements for electrical characteristic. The results detected by AFM indicate in a qualitative and quantitative manner how the surface properties (topography, roughness) vary with Mg concentration. The optical characterization showed that the transmittance of MZO thin films increased from 75 to about 90% and optical band gap energy from 3.20 to 3.43 (eV). The electrical properties study showed the lowest resistivity value was 3.45 × 10−2 (Ω·cm), which was obtained for the film doped with ZnO:Mg (2 at.%). In order to confirm our results on optical properties, the band structure of Wurtzite Zn1−xMgxO was calculated by ab initio calculations using the Korringa–Kohn–Rostoker (KKR) method combined with the coherent potential approximation (CPA). Keywords: ZnO, Thin films, Spray pyrolysis, Optical properties, Ab-initio calculations