THE INFLUENCE OF EXCITON FIELD DISSOCIATION ON THE EFFICIENCY OF PHOTOELECTROCHEMICAL PRODUCTION OF HYDROGEN

The influence of external bias on spectral dependences of the photocur rent through a ZnO-electrolyte junction was investigated. The observed peculiarities can be explained by field dissociation of excitons. A t heoretical model of the process was developed. The model considered as sumes that charge carriers are born as a result of both thermal and fi eld dissociation of excitons. It is shown that the photocurrent in the exciton absorption region for ZnO crystals can be conditioned only by field dissociation, which is of a threshold type. It is also shown th at, in photoelectrochemical reactions, both bulk and surface excitons can participate.