PROCESS FOR PREPARING In2O3-SnO2 PRECURSOR SOL AND PROCESS FOR PREPARING THIN FILM OF In2O3-SnO¿2?

摘要

A process for preparing a transparent conductive thin film of In2O3-SnO2 on the surface of a substrate of a plastic having poor heat resistance in addition to a glass or ceramic substrate. In the hydrolysis and polymerization of a solution containing an indium alkoxide and a tin alkoxide to prepare an In2O3-SnO2 precursor sol, tr-s-butoxyindium or tri-t-butoxyindium is used as the indium alkoxide. Further, the addition of water to the alkoxide-containing solution is carried out at a temperature of -20 °C or below. The surface of the substrate is coated with the In2O3-SnO2 precursor sol thus prepared to form a gel film. The gel film is irradiated with ultraviolet light at a wavelength of not more than 360 nm, or alternatively irradiated first with ultraviolet light at a wavelength of not more than 260 nm and then with laser beam at a wavelength of not more than 360 nm, thereby crystallizing the gel film to form a conductive thin film of In2O3-SnO2 on the surface of the substrate.