Effects of annealing environments on structural, surface topological and optical properties of Gd-doped ZnO films: a comparative study of argon and air annealing

This study investigated the effect of the annealing environment on the properties of Gd-doped ZnO films. The films were prepared using a sol-gel spin coating technique and annealed in argon (Ar) and air environments. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used to analyze the structural and surface topological properties of the films. The optical transmittance of the films was characterized using UV–Visible spectroscopy. Our results reveal that annealing environment significantly affects the properties of the Gd-doped ZnO films. Ar annealing improves the crystalline quality and surface topography of the films, whereas air annealing affects the optical properties of the films, particularly at high Gd concentrations. These findings can be useful for optimizing the processing conditions of Gd-doped ZnO films and for improving their performance in various optoelectronic applications.