Preparation of Ni0.4Cu0.6Al2O4/TiO2 composite thin film electrode and evaluation of its photoelectric properties

The composite spinel-type Ni_0.4Cu_0.6Al₂O₄ nanoparti-cles have been synthesized by a sol-gel method, and 0%, 2%, 4% and 6wt% Ni_0.4Cu_0.6Al₂O₄ doped pure TiO₂ (P25) powders were made into slurries. Ni_0.4Cu_0.6Al₂O₄/TiO₂ composite thin films were prepared on compact TiO₂ film coated with ITO conductive glass by screen printing method, and as the photoanode was assembled into sensitized solar cells. The crystal structure and spectral response were characterized by powder X-ray diffraction and ultraviolet-visible diffuse reflectance spectrum. The performance of sensitized solar cells of Ni_0.4Cu_0.6Al₂O₄ nanoparticles has been tested by Solar Simulator. The influences of doping amount of mixed spinel on photoelectron properties of composite thin films and photoelectron conversion efficiency of assembled battery have been investigated. The results show that Ni_0.4Cu_0.6Al₂O₄ powder possesses spinel structure and have excellent visible-light response, the band gap is only 1.48eV, the efficiency and optical performance of solar cell is increased and improved. When the doping is 4%, the composite thin film photoelectric conversion efficiency η is 3.26%, while pure TiO₂ film cell efficiency η is only 1.79%, the doped cell photoelectric conversion efficiency is enhanced by 45 %.