Structural and morphological properties of sol-gel ZnO:Ni films

Ni doping induces modifications and considerable changes in the optical, electrical and magnetic properties of ZnO films. In this work, the influence is discussed of Ni-doping (two nickel concentrations) and annealing temperature (ranging from 300 degrees C to 800 degrees C) on the structural and optical properties of sol-gel derived ZnO: Ni films. Uniform and smooth films were obtained by spin-coating on quartz and Si substrates. The ZnO: Ni films were crystallized in wurtzite phase with no impurity phases found for annealing temperatures up to 600 degrees C. The size of the crystallites was strongly affected by the Ni content and the heat treatment. Furthermore, the Ni doping improved the optical transparency of the sol-gel films, while the AFM studies showed that the film morphology and the roughness were influenced by the nickel doping.