On the basis of our previous report [S. Cai, T. Lu and M. Zhou, Electrochim. Acta 36 1585 (1991)] that the sintered Zn-doped iron oxide electrode showed strange photoresponses of n-type semiconductive characteristics at more positive potential, p-type semiconductive characteristics at more negative potential and both n-type and p-type semiconductive characteristics at intermediate potential, a primary mechanism for this phenomenon is presented in this paper. The energy band diagram at one electrode with n-type and p-type semiconductors is given. By using ...
