Fabrication of the PSCs

The fluorine doped tin oxide (FTO) substrate was etched with Zn dust and 2 M hydrochloric acid and cleaned with acetone and 2-propanol for 10 min respectively. The FTO substrate was dried with nitrogen and exposed to oxygen plasma treatment. To creat the TiO₂ compact layer (CP-TiO₂), 0.10 M titanium diisopropoxide bis (acetylacetonate) (Sigma-Aldrich, 75 wt%, in IPA, Signa-Aldrich) solution was deposited on the FTO substrate and annealed at 450 °C for 30 min. The PANI solution was then coated onto the CP-TiO₂ layer. A mixture solution of 1.0 M PbI₂ (1.0 M, Sigma-Aldrich) and 1.0 M CH₃NH₃I in N,N-Dimethylformamide (DMF), and dimethylsulfoxide (DMSO) at a ratio of 4:1 (v:v), was coated on the PPL and dried at 100 °C for 10 min. A Spiro-MeOTAD containing [28.8 μL of Spiro-MeOTAD (Lumtec) (72.3 mg/mL in chlorobenzene), 4-tert-butylpyridine (Sigma-Aldrich, 96% The TSFI stock solution (Sigma-Aldrich, 99.8%) was stirred for 24 h)] was coated on the MAPbI₃ layer. A gold electrode was created using thermal evaporation equipment.