Unveiling the impact of TiCl4 surface passivation on dye-sensitized solar cells: enhancing charge transfer kinetics and power conversion efficiency

Abstract

Dye-sensitized solar cells (DSSCs) have gained considerable attention as a viable substitute for traditional silicon-based solar cells owing to their cost-effectiveness and superior efficiency. However, one of the major challenges in developing DSSCs is their susceptibility to recombination losses, which can significantly reduce their efficiency. Surface passivation is a key approach to address this issue by reducing the density of surface states and enhancing charge separation. This study focuses on the role of surface passivation in DSSCs, which involves the use of TiCl4 in different concentrations (10–30 mM) over the mesoporous TiO2 layer to reduce surface recombination. Based on our research, we found that optimizing the concentration of TiCl4 to 20 mM considerably enhanced the structural, optical, electrical, and charge transport properties of the TiO2 photoanodes, leading to improved ability to capture and utilize light energy into useful power in the pertinent DSSC. A DSSC treated with 20 mM TiCl4 demonstrated an excellent power conversion efficiency (PCE) of 7.04%, about 30% higher than the untreated DSSC. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.