Improved photovoltaic performance of dye-sensitized solar cells using dual post treatment based on TiCl4 and urea solution

An effective and efficient photovoltaic performance is significantly affected by the interface between different constituents of dye sensitized solar cells (DSSC). A novel dual post treatment of TiCl 4 and urea solutions on different layers of TiO 2 electrode is addressed and the TiO 2 particle morphology, dye-adsorption amount on the TiO 2 electrode and the photovoltaic performance of the DSSC based on those electrodes are characterised in this work. TiCl 4 treatment can form more binding site on TiO 2 particles and urea treatment structures a thin layer of g-C 3 N 4 on the surface of TiO 2 particles. This strategy can not only effectively increase the dye-adsorption for light-harvesting, but also facilitate the electron transfer through inhibiting the charge recombination between TiO 2 and electrolyte, and moreover, it provides excess electrons for the photoanodes. The DSSC fabricated from TiO 2 electrode processed with urea treatment on the sixth layer exhibited the highest power conversion efficiency of 8.94% with a short current density J sc of 24.09 mA cm –2 , an open circuit voltage V oc of 583 mV and a fill factor of 63.8.