Solvothermal synthesis of TiO₂ nanorods to enhance photovoltaic performance of dye-sensitized solar cells

In this study, rod shaped TiO₂ nanocrystals with excellent crystallinity were obtained by a simple solvothermal approach utilizing isopropyl alcohol without the use of any surfactants or capping agents. The solvothermal process parameters such as the concentration of titanium(IV) isopropoxide and volume of acetic acid were varied to reach optimal synthesis conditions to prepare well-defined and monodispersed TiO₂ nanorods. The growth of rod shaped TiO₂ nanocrystals has also been investigated by varying the solvothermal reaction durations and temperatures. TiO₂ nanorods with various film thicknesses were used as photoanodes to fabricate dye-sensitized solar cells (DSSCs). A power conversion efficiency of 9.21% has been achieved for the DSSC fabricated using a TiO₂ nanorod photoanode film with 14 μm thickness. The high photovoltaic performance was attributed to the effective electron transfer of photogenerated electrons in TiO₂ nanorod films with enhanced dye adsorption which was favored for efficient light harvesting ability.