The Production of Thin Metal Oxide Films by Spray Pyrolysis Using Supercritical CO2-Assisted Aerosolization of Aqueous Solutions

Abstract

Thin metal oxide films have been deposited onto various substrates, under ambient pressure, utilizing supercritical CO2-assisted nebulization of aqueous solutions. In this process, supercritical CO2 is contacted with an aqueous precursor solution inside a low-dead-volume tee. The resulting emulsion is allowed to expand out of a capillary restrictor, and the fine particle aerosol formed is directed toward heated substrates. Dehydration, pyrolysis and oxidation of the precursors occur at or near the surface of the substrate to form the desired metal oxide film. Thin films of zinc oxide, zinc gallate and manganese-doped zinc gallate have been prepared using this technique.