AN INVESTIGATION OF THE ELECTROCHEMICAL AND PHOTOELECTROCHEMICAL PROPERTIES OF THE CUPROUS OXIDE LIQUID PHASE BOUNDARY

摘要

In view of the possible application of cuprous oxide in solar energy conversion its physical properties and photoelectrochemical behavior of the phase boundary between the Cu2O and liquid have been investigated. The composition of galvanostatically deposited films is pure Cu2O, but its structure is disordered. The conductivity is due to carriers hopping between localized energy states. At room temperature thin Cu2O films behave like n-type semiconductors. On the basis of the experimental data an energy scheme for the thin oxide semiconductor film is given. From the representative voltammograms in the dark and under illumination it could be concluded that the currents are changed under illumination and that photodegradation takes place. Some unusual phenomena are discussed on the basis of the properties of the thin oxide/electrolyte phase boundary where surface effects are more pronounced than in the bulk material. The conversion efficiency of the Cu2O photoanode in photoelectrochemical cells is below 1. An analysis of the causes of this poor performance is given. References: 23