Electrochemical, solid state, photochemical and technological aspects of photoelectrochemical energy converters

Different aspects of photoelectrochemical energy conversion are discussed. It is shown, by conservative estimates of the energy losses in such a system, that the available photopotential is smaller than the optical bandgap of the semiconductor by at least 1 eV. It is shown that water decomposition using only one photosensitive electrode is energetically unfavourable and that, even when two photosensitive electrodes, are used, the production of electrical current is to be preferred over that of hydrogen.