Morphology control of highly-transparent indium tin oxide thin films prepared by a chlorine-reduced metallo-organic decomposition technique

Indium tin oxide thin films were prepared by a chemical solution deposition route based on a one pot reaction of indium acetate, tin tetrachloride pentahydrate and propionic acid. The films were heat-treated in oxidising atmosphere and post-annealed in forming gas containing 10% hydrogen. It was found that the coating solution concentration exerted a major influence on the morphology of the films. Low-concentrated solutions yielded layers with columnar structure while higher molarities led to fine-grained granular films. Under optimised conditions, thin films of indium tin oxide exhibiting a resistivity of 1 · 10− 3 Ω cm were obtained. The transparency was determined to a high level of above 90% in the entire visible range of the spectrum.