Improved photovoltaic performance of dye-sensitized solar cells (DSSCs) by Zn + Mg co-doped TiO2 electrode

Abstract Zn + Mg co-doped TiO 2 and the pure TiO 2 nanoparticles were prepared by the hydrothermal method. The pure TiO 2 and Zn + Mg co-doped TiO 2 were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron miscroscopy, energy dispersive X-ray, UV–vis diffuse reflectance absorption spectra. Under a simulated solar light irradiation of 100 mW cm −2 , the cell based on doped TiO 2 electrode achieved a conversion efficiency of 9.07%, which is noticeably increased by 26.7% compared with undoped TiO 2 based DSSC (7.16%). The enhancement of conversion efficiency of the Zn + Mg co-doped TiO 2 was attributed to the positive shift of the flat band potentials and fast electron transport in TiO 2 films. The mechanism was suggested by intensity modulated photocurrent spectroscopy and intensity modulated photovoltage spectroscopy measurement.