Interfacial Electronic Properties and Adjustable Schottky Barrier at Graphene/CsPbI3 van der Waals Heterostructures

2D materials have attracted much attention for applications in halide perovskite optoelectronic devices due to their high carrier mobility and adjustable work function. Heterogeneous stacking of halide perovskites with 2D materials to form heterostructures is an effective way to improve the performance of perovskite photovoltaic and optoelectronic devices. Herein, the investigation of the interfacial interactions and electronic properties of graphene/CsPbI 3 heterostructures with two types of exposed surfaces of CsPbI 3 by first‐principles calculations is reported. The calculated results show that the intrinsic electronic properties of isolated graphene and the CsPbI 3 slabs are well preserved in the heterostructures, and the interaction between the heterostructures is a weak van der Waals (vdW) interaction. The Schottky barriers are built in the vdW heterostructures with the optimized layer‐to‐layer distance. The barrier height can be tuned by doping graphene with boron and nitrogen atoms and by applying an external electric field. This work provides useful information for designing next‐generation electronic devices based on graphene/CsPbI 3 vdW heterostructures.