Effect of Acetic Acid in TiCl₄ Post-Treatment on Nanoporous TiO₂ Electrode in Dye-Sensitized Solar Cell

Titanium tetrachloride (TiCl₄) is adopted as a post-treatment on the nanoporous titanium oxide (TiO₂) layers to enhance the performance of dye-sensitized solar cells (DSCs). A TiCl₄ post-treatment is capable of improving electron transport and dye-loading on the surface of TiO₂ layers. In this study, the TiCl₄ solution mixed with acetic acid was employed to enhance the condition of the TiCl₄ post-treatment. Since acetic acid in the TiCl₄ 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.