Dip coated ITO thin-films through sol–gel process using metal salts

Abstract Indium tin oxide (ITO) thin-films were deposited on soda-lime-silicate glass using sols prepared from alcoholic solutions of indium chloride and stannic chloride with different In:Sn atomic ratios, namely 95/5, 90/10, 85/15 and 80/20. The electrical properties, structure and morphology of the thin-films were investigated. All the films studied, with a thickness range of 10–490 nm were polycrystalline with grain sizes in the range of 25–60 nm. Uniform and dense microstructure apparently devoid of cracks and voids were observed. Only cubic In 2 O 3 phase was observed in the X-ray diffraction (XRD) and transmission electron microscopy (TEM). SnO and SnO 2 phases were not detected. The sheet resistance values decreased with increase in coating thickness. A significant decrease in the resistance values was also noted after annealing in N 2 \H 2 (96–4%) atmosphere. The minimum sheet resistance values were noted for Sn concentration of 10 at.%. The lowest value, 11 ohms per square, was obtained after annealing for a 490-nm film.