Effect of MnTiO₃ surface treatment on the performance of dye-sensitized solar cells

We investigate the effect of MnTiO₃ surface treatment on the performance of dye-sensitized solar cells (DSSCs). The MnTiO₃-treated TiO₂ sample reveals a smoother surface with fewer cracks than the bare TiO₂ sample. It is shown that the MnTiO₃ is an amorphous layer (∼2 nm thick). The MnTiO₃-treated TiO₂ sample exhibits higher absorbance across the wavelength region of 450-800 nm than the bare TiO₂ sample. The MnTiO₃-treated sample gives the higher point of zero charge than the bare sample. Measurements show that the open-circuit voltage and the short circuit current are 0.64 and 0.67 V and 12.3 and 15.7 mA/cm² for DSSCs with the bare and MnTiO ₃-treated TiO₂ electrodes, respectively. The MnTiO ₃ treatment improves the cell efficiency by about 25%.