Effect of acetic acid in TiCl ₄ post-treatment on nanoporous TiO ₂ electrode in dye-sensitized solar cell

Titanium tetrachloride (TiCl ₄) is adopted as a post-treatment on the nanoporous titanium oxide (TiO ₂) layers to enhance the performance of dyesensitized solar cells (DSCs). A TiCl ₄ post-treatment is capable of improving electron transport and dye-loading on the surface of TiO ₂ layers. In this study, the TiCl ₄ solution mixed with acetic acid was employed to enhance the condition of the TiCl ₄ post-treatment. Since acetic acid in the TiCl ₄ solution prevents the formation of impurities and facilitates the crystallization, it improves dye adsorption and electron transport properties. To analyze the performance of the cell, we measured X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface measurements, UV-vis spectroscopy and electrochemical impedance spectroscopy (EIS) and photocurrent-voltage (I-V) measurements.