Incorporation of Mn2+ and Co2+ to TiO2 nanoparticles and the performance of dye-sensitized solar cells

Dye-sensitized solar cells were fabricated using (Mn and Co) M-doped TiO2 electrodes which were successfully synthesized via the hydrothermal method. Furthermore, the effect of Mn2+ and Co2+ ions content on the properties of TiO2 electrodes was studied. The materials were characterized by XRD, TEM/HRTEM, EDS, BET specific surface area (SBET), pore-size distribution by BJH, UV–Vis Spectroscopy, and their photoconversion efficiencies were evaluated using I–V characterization, IPCE and EIS. X-ray diffraction results reveal both undoped and M-doped TiO2 structure without any impurity phase. The X-ray diffraction patterns of the (Mn and Co) ions doped TiO2 is almost the same as that of pure TiO2, showing that (Mn and Co) have little influence on the formation of anatase titania. The influence of dopant (Mn, Co) ions on band energetics and photoelectrochemical properties of nanostructured TiO2 electrodes was investigated. The total trap densities were remarkably increased as TiO2 electrodes were doped with (Mn and Co). Experiment results showed that the content of M-doped TiO2 plays an important role in the photoelectrochemical properties. The conversion efficiency was decreased with (Mn and Co)-doped TiO2 electrodes under irradiation of 100 mW/cm2 white light due to the high change of flat band edge and the charge recombination which happened related to trap density of TiO2 electrodes with (Mn and Co) ions doping.