(668c) Preparation of ITO Mesoporous Thin Films by a Surfactant-Templated Sol-Gel Route

Abstract: Mesoporous conductive metal oxide thin films are extremely desirable components for electrochemical systems because of their high surface area and well-defined pore geometry. Thus, our group recently began working on preparing transparent conductive supports for photochemically active oxides. Indium-tin oxide (ITO) mesoporous thin films are deposited on glass slides through an evaporation-induced-self-assembly (EISA) process with Pluronic surfactants P123 and F127 as templates. The initial so-gel solution is prepared by mixing indium chloride hydrate, tin chloride hydrate, and P123/F127 dissolved in anhydrous ethanol. After deposition by dip coating, the as-synthesized thin films are calcined under conditions adjusted to preserve the mesostructure while allowing the formation of the ITO phase. Under the optimum condition, transparent films with mesopostructures having two dimension hexagonal or cubic symmetry can be prepared using P123 or F127 as template. The primary challenge, however, is finding the conditions necessary to preserve those mesostructrures while generating films with nanocrystalline ITO domains. The electrical and optical properties of the films are investigated, and the amount of Sn is varied to achieve the minimum resistivity of the mesoporous ITO thin films.

Keywords: ITO, conductive, thin films, sol-gel, templated, mesoporous