Photoconductivity and generation of a photo-emf in a semiconductor bicrystal

A diffusion theory of carrier transport across a grain-boundary barrier is used to study the influence of photoexcitation on the current-voltage characteristic of a bicrystal with n-type grains and acceptor surface states at the grain boundary. Possible generation of a photo-emf in such a bicrystal is investigated on the assumption that the rate of photogeneration of electron-hole pairs g1 and the hole lifetime T1 on one side of the grain boundary are generally different from the corresponding values of g2 and T2 on the other side. The results are given of a numerical calculation of the current-voltage characteristic of a wide-gap semiconductor bicrystal with different values of g1, g2, T1, and T2