Chlorine-Doped Perovskite Oxide: A Platinum-Free Cathode for Dye-Sensitized Solar Cells

Triiodide/iodide (I3-/I-) redox couple-mediated solar cells, batteries, and electrochromic devices require highly efficient and stable electrocatalysts for I3- reduction reaction (IRR) to overcome performance limitations, whereas the widely used platinum (Pt) cathode for IRR has limitations of high price and unfavorable durability. In this work, we present a halogen element (chlorine) doping strategy to design low-cost perovskite-type electrocatalysts with enhanced IRR activity and stability. The dye-sensitized solar cell (DSSC) assembled by the LaFeO2.965-{$\delta$}Cl0.035 cathode delivers an attractive power conversion efficiency (PCE) of 11.4\% with a remarkable PCE enhancement factor of 23\% compared with Pt, which is higher than most of the reported non-Pt DSSC cathodes.