Effect of Cu-doping on the microstructural and optical properties of Mg0.2Zn0.8O thin films prepared by sol–gel spin coating

Cu-doped Mg0.2Zn0.8O thin films were synthesized by sol–gel spin coating. We investigated the microstructural and optical characteristics of the Cu-doped Mg0.2Zn0.8O thin films. By increasing the Cu content of the source, Cu-doped Mg0.2Zn0.8O thin films were phase-separated into Cu-rich and Cu-poor areas, which could be a result of the limited Cu solubility in the Mg0.2Zn0.8O lattice. As the annealing temperature increased, the crystallinity of the Cu-doped Mg0.2Zn0.8O thin films improved. Cu doping in Mg0.2Zn0.8O thin films resulted in a decrease of both intensities for UV and visible emissions without a shift of the peak positions in the photoluminescence spectrum. •Cu-doped Mg0.2Zn0.8O thin films were fabricated using sol–gel spin coating.•By increasing the Cu content, Cu-doped Mg0.2Zn0.8O thin films were phase-separated.•As the annealing temperature increased, the crystallinity of the thin films improved.•Cu doping in Mg0.2Zn0.8O thin films resulted in a decrease of optical emissions.