ELECTRICAL AND OPTICAL-PROPERTIES OF THE SYSTEM TIO2-XFX

A convenient method for preparing compounds in the system TiO2-xFx has been developed. The electronic and photoelectric properties of samples prepared accordingly have been studied. The fluorine content was found to be an essentially linear function of the reaction temperature over the range 575-700°C. The saturation photocurrent increased with decreasing fluorine content, because of increased response at the longer wavelengths. This improved response may be attributed to the increase in depletion-layer width arising from the observed increase in resistivity. A significantly larger saturation photocurrent was obtained from samples of TiO2-xFx than from comparable samples of TiO2-x under the same conditions. The increased output may be attributed to a decrease in the recombination rate brought about by the filling of oxygen vacancies. The long-term stability was studied, and a sample of TiO2-xFx was found to be at least as stable, in a suitable electrolyte, as comparable TiO2-x. © 1979, American Chemical Society. All rights reserved.