PHOTOELECTROCHEMICAL STUDIES OF ION IMPLANTED TiO//2 FILMS.

Titanium dioxide films of 40 nm thickness have been ion implanted with palladium, iron and xenon in the concentration range 0. 1 to 10%. By varying the implantation energy an almost uniform distribution was achieved. Photoelectrochemical investigations show that the implantation increases photocurrents with the most pronounced effect being caused by Xe implantation. The evaluated band gap energies are not strongly altered by ion implantation. The potential dependence is changed considerably towards a much stronger influence of the electrode potential which is suggested to be due to the Poole-Frenkel effect. There is a strong indication that the conduction band is partially localized by the implantation process while the introduction of additional electronic terms in the case of Pd and Fe is of minor importance.