Abstract: Zn-doped iron oxide electrodes that exhibit n-type and p-type photoresponses simultaneously at certain potential interval were prepared. Transformation of n-type photoresponse at more positive potential to p-type photoresponse at more negative potential was showed. The photo-voltage waveforms at different potentials were explicitly measured. It was found that the waveforms at intermediate potentials are linear pile of typical n-type and p-type waveforms. A model based on the existence of multiphase both on the surface and in the bulk of the electrode was advanced.

Key words: photoelectrochemistry, iron oxide electrode, photoresponse