Realization of multifunction in perovskite-based van der Waals heterostructure by interface engineering strategy: The case of CsPbBr3/Janus MoSSe

The flexibility and versatility is crucial for the perovskite-based heterostructure to realize multifunctional integration, while it is hard to be achieved in the conventional systems. Herein, we propose an interface engineering strategy, which utilizes the structural characteristics of perovskite and the mirror asymmetry of 2D Janus material to realize the multifunction of CsPbBr3/Janus MoSSe heterostructure. We demonstrate that type-I and type-II band alignment can be achieved simultaneously in CsPbBr3/ Janus MoSSe heterostructure by modulating the atomic terminal contacts. The underlying mechanism is that the band alignment can be shifted by the interface dipole and its induced interface potential step. The interface effect renders CsPbBr3/Janus MoSSe heterostructure an adjustable band gaps and band types, and an improved light absorption range and intensity in the visible and ultraviolet regions. More promisingly, we find that gate voltage regulation can also realize the transition of band alignment from intrinsic type-II to type-I or type-III for CsBr-T/ SMoSe heterostructure. These findings enrich the functionality of perovskite-based heterostructures and provide more possibilities for realizing high-efficiency multifunctional nanodevices.