Preparation of nano-crystal N-Zn/TiO2 anode films and the effects of co-sensitization on the performance of dye-sensitized solar cells

Abstract

A nano-crystal N-Zn/TiO2 anode film was prepared using a combined technology. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry characterizations showed that the two elements N and Zn were doped into nano-crystal TiO2 successfully. This resulted in a strong redshift in the UV-Visible spectrum. UV-Visible measurements showed that the light absorption of N719 and P3OT were complementary and covered the entire visible region. This led to a high utilization of visible light. Solar cells based on the N-Zn/TiO2 anode film were co-sensitized using P3OT and N719. The cells have a short-circuit current density of 7.91 mA/cm2, an open-circuit photovoltage of 0. 659 V, and a photoelectric conversion efficiency of 2.64%. Also, the relationship among the N-Zn/TiO2-film anode's electric structure, the dye's LUMO, electrochemical impedance, and photoelectric conversion efficiency are discussed in the paper. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.