Investigation of Enhanced Photoelectrochemical Property of Cerium Doped Hematite Film Prepared by Sol-Gel Route

Cerium doped iron oxide thin film was successfully prepared by sol-gel route. Their physical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectra (XPS) and UV-visible absorbance spectra. Ce doped Fe2O3 films exhibit features of hematite crystallographic phase from XRD results. Particles on the surface are wormlike after heat treatment from the morphology analysis. The incident photon to electron conversion efficiency (IPCE) of Ce doped hematite is 14% (400nm) at 0.4V vs. NHE, which is higher than the undoped hematite film. Cerium in hematite lattice could improve the conductivity of the thin film. Therefore the photo generated carriers could live longer rather than recombining with each other rapidly as in the undoped hematite. The estimated surface carrier concentrations Nd are about 1.2×1019 cm-3 and 8.1×1018 cm-3 for Ce doped and undoped films, respectively. Higher Nd could also contribute to better PEC performance.