摘要：SummaryAlthough perovskite/two-dimensional (2D) materials heterojunctions have been employed to improve the optoelectronic performance of perovskite photodetectors and solar cells, effects of the intrinsic potential difference (ΔVin) of asymmetrical 2D materials, like Janus TMDs (J-TMDs), were not revealed yet. Herein, by investigating the optoelectronic properties of CsPbI3/J-TMDs heterojunctions, we find a reversible type-II band alignment related to the intensity and direction ofΔVin, suggesting that carrier transport paths can be reversed by modulating the contact configuration of J-TMDs in the heterojunctions. Meanwhile, the band offset, carrier transfer efficiency and optical properties of those heterojunctions are directly determined by the intensity and direction ofΔVin. Overall, CsPbI3/MoSSe heterojunction is suggested in this work with a tunneling probability of 79.65%. Our work unveils the role ofΔVinin asymmetrical 2D materials on the optoelectronic performances of lead halide perovskite devices, and provides a guideline to design high performance perovskite optoelectronic devices.Graphical abstractDisplay OmittedHighlights•An intrinsic potential difference (ΔVin) exists in asymmetrical Janus TMD (J-TMD)•A reversible type-II band alignment realized by modulating the contact configuration•The transport performance of CsPbI3/J-TMD heterojunction directly determined byΔVin•The optical absorption is enlarged by modulating the direction and intensity ofΔVinSurface chemistry; Nanotechnology; Materials science
