Fig. 7

Surface passivation engineering of the PVK SC. a Schematic of the crystallization of the MAPbI₃ SCTF at high (left) and low (right) temperatures. b Temperature-dependent solubility of MAPbI₃ in GBL (orange line) and PC/GBL (blue line) solvent mixture. c XRD patterns of the MAPbI₃ SCTF grown at high (orange line) and low (blue line) temperatures. Reproduced with permission from Ref. [72]. Copyright 2020, American Chemical Society. d Crystal structure of the MAPbI₃ SC, and schematic of the surface treatment of the SC using MA gas. e SEM images of the MAPbI₃ SC without and with MA gas surface treatment. f PL spectra of the MAPbI₃ SC without and with MA gas surface treatment. Reproduced with permission from Ref. [73]. Copyright 2018, American Chemical Society. g Schematic of the MAI surface treatment on the MAPbI₃ SCTF. Device structures and energy levels for the MAPbI₃ SCTF solar cells without and with MAI surface treatment. Reproduced with permission from Ref. [74]. Copyright 2020, Springer Nature. h Schematic of the surface treatment and device fabrication of the MAPbBr₃ SC. i Polar solvent is tert-amyl alcohol; the nonpolar solvent is cyclohexane, and the passivation agents are methylammonium bromide and phenylethylammonium bromide. Reproduced with permission from Ref. [75]. Copyright 2022, American Chemical Society