The effect of switchable electronic polarization states on the electronic properties of two-dimensional multiferroic TMBr2/Ga2SSe2 (TM = V–Ni) heterostructures

Abstract

Multiferroic van der Waals (vdW) heterostructures (HSs) prepared by combining different ferroic materials offer an exciting platform for next-generation nanoelectronic devices. In this work, we investigate the magnetoelectric coupling properties of multiferroic vdW HSs consisting of a magnetic TMBr₂ (TM = V–Ni) monolayer and a ferroelectric Ga₂SSe₂ monolayer using first-principles theory calculations. It is found that the magnetic orderings in the magnetic TMBr₂ layers are robust and the band alignment of these TMBr₂/Ga₂SSe₂ HSs can be altered by reversing the polarization direction of the ferroelectric layer. Among them, VBr₂/Ga₂SSe₂ and FeBr₂/Ga₂SSe₂ HSs can be switched from a type-I to a type-II semiconductor, which allows the generation of spin-polarized and unpolarized photocurrent. Besides, CrBr₂/Ga₂SSe₂, CoBr₂/Ga₂SSe₂ and NiBr₂/Ga₂SSe₂ exhibit a type-II band alignment in reverse ferroelectric polarization states. Moreover, the magnetic configuration and band alignment of these TMBr₂/Ga₂SSe₂ HSs can be further modulated by applying an external strain. Our findings suggest the potential of TMBr₂/Ga₂SSe₂ HSs in 2D multiferroic and spintronic applications.