A doped heterojunction photoanode: a strategy-driven approach to improve the charge carrier dynamics and photoconversion performance of the TiO2-based dye-sensitized solar cell

The synergy of doping and heterojunction in developing a doped heterojunction photoanode and its influence on DSSC performance are explored in the present work. Herein, Fe-doped biphasic TiO2 heterojunctions are synthesized via a sol-gel process with varied anatase-rutile (A/R) phase ratios. The doped biphasic heterojunctions exhibited a superior photoconversion efficiency (PCE) compared to pristine counterparts, among which the photoanode with a 1.50 A/R ratio (FT-400) showed the highest efficiency. This can be attributed to the effective photon utilization of FT-400 due to the high surface area and low crystallite size coupled with better charge transport and reduced recombination losses. A higher value of JSC and VOC indicated a high electron concentration and a shift in the fermi level in the sample. The synergy of doping and heterojunction in TiO2 photoanode leads to elevated photon absorption and effective charge transport and it opens up an era of research for photoanode improvement.