On the Rectification of Anodic Oxide Films of Titanium

Abstract

The phenomenon of electrolytic rectification in anodic oxide films has been studied extensively for the valve metal‐valve metal oxide‐electrolyte system for many years. This paper describes experimental results on the rectification of the electric current in anodic oxide films, especially enclosed between two metallic electrodes. The rectification of the electric current is interpreted on the basis of a p‐n junction within these oxide films. In addition, these junctions can exhibit photovoltaic effects and can be used for the fabrication of field effect devices. In these field effect transistors the electrical current flowing between two narrowly spaced electrodes deposited on the oxide surface can be modulated by the application of voltage to the titanium bottom electrode. This experiment shows that a conductive surface layer is adjacent to an insulating layer underneath.