Study of the structure of passivated vanadium–titanium alloys and their semiconductor properties

Abstract.

The possibility of investigating the photocurrent behavior and structure of electrochemically prepared passive films on metallic titanium and on binary vanadium–titanium alloys has been demonstrated. The semiconductor properties were characterized by measuring the dependence of the photocurrent on the wavelength of the incident light and on the electrode potential. The results showed the oxide layers to be n-type semiconductors with a bandgap between 2.6 and 3.3 eV and a flatband potential of approximately –300 to +400 mV (relative to the SCE). The results were interpreted in terms of the corrosion characteristics of the materials. XPS measurements on pure vanadium and some alloys are presented. Several properties were used to characterize the passive surface of these materials. The V₂O₅ and TiO₂ content decreases with increasing depth.