Fig. 8

Surface orientation engineering of PVK-SC. a Photographs of the MAPbI₃ SC showing continuous morphological transition triggered by the addition of oleylamine ligand to the solution. b I–V curves of the MAPbI₃ SC photodetector. c Calculated responsivity of the polycrystalline thin film, SC (100) facet, and SC (002) facet photodetectors. Reproduced with permission from Ref. [77]. Copyright 2017, American Chemical Society. d Dark and photocurrents curves of (100) and (220) facet photodetectors, respectively. e Diagrams of surface structures on (100) and (220) facets of the MAPbI₃ SC. [78]. Copyright 2017, American Chemical Society. f Schematic of MAPbI₃ SCTFs with preferred (001) and (100) orientations. g XRD patterns of MAPbI₃ (001) and (100) SCTFs. Insets are photographs of SCTF samples. h Diagrams of crystal structures of tetragonal-phase MAPbI₃ with different exposed facets. Reproduced with permission from Ref. [79]. Copyright 2022, American Chemical Society. i Schematic of the α-FAPbI₃ crystal with three facets. j SEM image of the PVK SC film with well-defined facets. k Photocurrent for the (100), (111), and (110) facets estimated based on Kelvin probe force microscopy (KPFM) and pc-AFM images. l Light stability measurement of the devices with different dominant facets. Reproduced with permission from Ref. [80]. Copyright 2022, Elsevier