Improved photovoltaic efficiency of dye sensitized solar cells by decorating TiO2 photoanode with barium titanate oxide

Abstract

The Barium Titanate Oxide (BTO) enhanced TiO2 nanorod array was successfully synthesized with different NaOH precipitating agent via two steps hydrothermal method. The structure and the morphology of products were characterized by XRD, SEM couple with EDS and TEM. The results showed the formation of BaTiO3 and BaTi4O9 phases on the TiO2 surface. The optical property of pure TiO2 and BTO-TiO2 heterostructure were investigated by UV–visible spectroscopy. The band gap of all BTO-TiO2 samples were only slightly decreased when compared to the bare TiO2 film. The photoconversion efficiency of the TiO2 and BTO-TiO2 photoanodes were measured from the J-V characteristic. The efficiency of DSSCs based on the pure TiO2 was 2.44% while the highest performance of DSSCs based on BTO-TiO2 was 4.29%. The charge transfer resistance and the electron lifetime (τe) were further investigated by the electrochemical impedance spectroscopy (EIS). The increase of DSSCs performance is due to the better charge transfer resistance and the lower recombination during the electrons transfer across the photoanode of DSSCs, as indicated from the Nyquist and Bode plots.