INFLUENCE OF COPPER ADDITION ON OPTICAL-PROPERTIES OF TIO2

Cu-doped TiO2 could be considered as a better absorber of sunlight for solar energy conversion. The Cu-doped TiO2 has been prepared by anodic oxidation of a Ti-2.5% Cu alloy. The structural properties of these anodic oxides are examined by electron microdiffraction, XPS, and nuclear microanalysis. The optical properties of both the Ti-Cu alloy and the anodic films have been determined as functions of the thickness of the oxides. It is concluded that Cu doping of TiO2 creates an extra state in the forbidden gap of TiO2 which gives two extra peaks in the absorption spectrum of the oxide. But for solar energy applications, the preparation of the doped oxide by anodic oxidation is not suitable because one does not control the level of impurity. © 1979, The Electrochemical Society, Inc. All rights reserved.