Stacking engineering in two-dimensional multiferroic CuInPS/CrI heterostructures.

Stacking engineering offers a powerful technique to achieve the desired properties of two-dimensional (2D) van der Waals materials interlayer coupling, thereby enabling multifunctional applications. In this study, we systemically investigated the electronic and magnetic properties of multiferroic heterostructures consisting of a ferroelectric (FE) monolayer of CuInPS and a ferromagnetic/antiferromagnetic (FM/AFM) monolayer/bilayer of CrI. Our first-principles calculations unveiled that the reversal of the polarization direction in CuInPS can effectively modulate the band gap, band alignment, band type and magnetic ordering of CrI. The formation of type II band alignment in the CuInPS-(P↓)/monolayer-CrI heterojunction results in strong photocatalytic activity under visible light. Additionally, the FE polarization-induced magnetic ground state transition from the AFM state to the FM state and enhancement of the magnetic transition temperature are identified in the CuInPS/bilayer-CrI heterostructure. Our work not only introduces promising candidates for the development of new electric field-modulated optoelectronic and spintronic devices, but also provides a manufacturable platform for in-depth exploration of magnetoelectric coupling in multiferroic heterostructures.