Fig. 4: Photovoltaic performance and stability.

a Schematic illustration of the fabricated p-i-n PSCs. ITO Indium tin oxide, SAM Self-assembled monolayer, 3D Three-dimensional; LD Low-dimensional, BCP Bathocuproine. b Photovoltaic performance statistics of the PSCs, based on the pristine CsFAMA perovskite, the 3F-PEA/CsFAMA heterojunction, and the DMS-modulated 3F-PEA/CsFAMA heterojunction. Avg represents the average PCE, and SD is the standard deviation, which are statistically obtained from 20 independent devices. The error bar is the positive deviation beyond 1.5 times the interquartile range (IQR), used to identify upper outliers. c J-V curves of the best-performing PSCs based on the DMS-modulated heterojunction, measured under forward and reverse scans. d Normalized PCE evolution of encapsulated devices, measured at MPP under continuous AM 1.5 G simulated solar illumination at room temperature (RT) in air (under ISOS-L-1 protocol). e J-V curves of best-performing 1 cm² PSCs based on the DMS-modulated heterojunction. f PCE statistics of PSCs incorporating different ligands, which include phenethylammonium iodide (PEAI), 4-fluoro-phenethylammonium iodide (4F-PEAI), 3-fluoro-phenethylammonium iodide (3F-PEAI), 4-(trifluoromethyl) phenethylammonium iodide (CF3-PEAI), and phenethylammonium chloride (PEACl), with DMS (orange color) and without DMS (blue color). The error bar is the positive deviation beyond 1.5 times the IQR, used to identify upper outliers. g Evolution of Voc and its standard deviation in PSCs processed with DMS (Square icons) and without DMS (circle icons) across different ligands, including PEAI, 4F-PEAI, 3F-PEAI, CF3-PEAI and PEACl.