Formation of an active electronic barrier at Al/semiconductor interfaces: A novel approach in corrosion prevention

Aluminum surfaces exhibit significantly improved corrosion protection when coated with suitable semiconductor/insulator thin films. These coatings, generally realized in metal-semiconductor (MS) or metal-insulator-semiconductor (MIS) structural configurations, lead to an interfacial electric field that acts as an effective built-in electronic barrier. This active barrier significantly impedes electron transfer from the aluminum surface to foreign species that cause oxidation by accepting the electrons. Anodic polarization data on numerous samples fabricated in both MS [e.g., Al-indium tin oxide (ITO)] and MIS (e.g., Al-SiO/sub 2/-ITO) configurations have demonstrated the protective nature of the built-in active electronic barrier