Semiconductor/Insulator Films for Corrosion Protection.
Abstract
Aluminum surfaces exhibit significantly improved corrosion protection when they are coated with suitable semiconductor/insulator thin films. These coatings, generally realized in Metal-Semiconductor (MS) or Metal-Insulator-Semiconductor (MIS) structural configurations, given rise to an interfacial electric field which acts as an effective built-in electronic barrier. This active barrier significantly impedes the transfer of electrons from the aluminum surface to foreign species which 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. A1-SiO2-ITO) configurations have demonstrated the protective nature of the built-in active electronic barrier. In particular, we have observed a rest potential of -1.126 volts (1% NaC1, 2pH solution) for A1-SiO2-pITO samples in polarization tests. The electronic barrier heights have been shown to increase with 1) the presence of a thin (20-100 A) SiO2 layer at the metal-semiconductor interface; and 2) the energy gap of ITO which depends upon the indium content. A comparison of these results with data obtained on plasma-deposited A1-Si3N4 samples is also presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1985
- Accession Number
- ADA169119
Entities
People
- F. Jain
Organizations
- University of Connecticut