Experimental and theoretical studies of Mg-doped ZnO (Mg:ZnO) for optoelectronic applications

Abstract

Thin films of pure and Mg-doped ZnO (Zinc Oxide) were successfully elaborated on glass substrates using the sol–gel technique. X-Ray diffraction patterns show that all grown films have good crystallinity and a hexagonal wurtzite structure, the (002) direction is the most preferred for thin-film growth. Atomic force microscopy (AFM) analysis showed that the surface is homogeneous and more compact with little change in surface morphology with increasing Mg doping rate, which agreed with the crystallite sizes obtained from the XRD results. The structural parameter “[Formula: see text]” measured and calculated using functional density increases while “[Formula: see text]” decreases. The electronic and optical bandgap and transmittance improve by increasing the concentration of Mg. The physical origin of the energy gap bowing parameter is investigated using the Zunger approach, which examines the microscopic origins of the energy bandgap bowing. In contrast, the reflectivity and electrical conductivity are reduced with increasing concentration of Mg. The experimental and theoretical results have the same tendency therefore, the Mg-doped ZnO (ZnO:Mg) is an essential candidate material for thin films in many optoelectronic devices.