Interfacial transport modulation by intrinsic potential difference of janus TMDs based on CsPbI3/J-TMDs heterojunctions

Abstract

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 of ΔVin, 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 of ΔVin. Overall, CsPbI3/MoSSe heterojunction is suggested in this work with a tunneling probability of 79.65%. Our work unveils the role of ΔVin in asymmetrical 2D materials on the optoelectronic performances of lead halide perovskite devices, and provides a guideline to design high performance perovskite optoelectronic devices.