Investigation of (Mg-Al) co-doped Zinc oxide thin films for photovoltaic harvesting energy devices

Undoped and Magnesium-Aluminum co-doped Zinc oxide thin films were successfully deposited by sol-gel technique onto glass substrates at optimized experimental conditions. The solution pH and the annealing temperature were maintained to 8 and 500 °C respectively. Doping is achieved by the simultaneous introduction of Aluminum and Magnesium in varying proportions but, keeping the molar amount of impurity constant and equal to 5%. Morphological and optical properties of ZnO films were assessed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns of the films showed the hexagonal wurtzite type polycrystalline structure. The SEM measurement showed that the surface morphology of the films was affected from the Al-Mg incorporation. The transmittance, extinction coefficient and bandgap were made to analyze the optical properties of studied films. The optimized results were obtained for co-doped (Al-Mg) concentration at ratio of 2/1.