Photovoltaic effect on titanium dioxide

Abstract

A necessary condition for the occurrence of the photovoltaic effect is the presence of a film of oxide, halogen or sulfur compounds of metals on the clean metal surface of the illuminated electrode. It can be stated that most of the studied photosensitive layers are compounds related to the type of semiconductors, and the photovoltaic element can be considered as a system consisting of a semiconductor bordering a metal electrode on one side, and an electrolyte on the other. Thus, it is natural to compare the photovoltaic effect with the internal photoelectric effect characteristic of semiconductors. The advantage of titanium dioxide over copper oxide is its chemical inertness, which allows for a wide variation in the conditions of the medium bordering the electrode. Based on the spectral characteristics of the positive and negative signs, it can be concluded that photocurrents of both signs are caused by electronic processes in the semiconductor that are independent of each other.