Hydrothermal Conversion Deposition of ZnFe_2O_4 doped TiO_2Thin Films and Their Photovoltaic Response

摘要

To improve its visible light response capability, a new narrow bandgap zinc ferrite semiconductor was in-situ introduced into the matrix of titanium dioxide nano film. ZnFe_2O_4 doped TiO_2 composite films have been successfully formed on glass and stainless steel substrates from aqueous solution through equilibrium reaction between iron (Ⅲ)-titanium (Ⅳ)-fluoric complex and boric acid, followed by in-situ hydrothermal conversion and crystallization in the Zn~(2+)-contained basic environment. The obtained films were densely packed and had no visible cracks; clear photovoltaic responses were observed in the anodic direction, and they were much larger in the presence of ferrite dopant. It is suggested that the shift of the corrosion potential was ascribed to photo-induced charge separation between the conduction band of ZnFe_2O_4 and its counterpart TiO_2 nano-particles.