Photoelectric properties of thin Eu3+-doped TiO2 films sensitized by cis-RuL2(SCN)2·2H2O

Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2 (SCN)2. 2H2O (L = cis-2,2′-bipyridine-4,4′-dicarboxlic acid) ruthenium complex were studied. The thin films were characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes to improving the photoelectric properties. It is found that an optimal composition doped with 0.2 mol. % Eu3+ exhibits the highest photoelectric properties. Isc is 0.37 mA.cm−2, which is 0.17 mA.cm−2 bigger than that of un-doped films; Voc is 405 mV, which is 50 mV bigger than that of un-doped films.