Multiferroic Van der Waals Heterostructure CuInP2S6/CuCrP2S6: Electrically Switchable Electronic Properties and Band Alignment

Abstract

Building van der Waals heterostructure is an effective method to design multiferroic materials. Here, by performing first principles calculations, we study the electronic and magnetic properties of CuCrP₂S₆/CuInP₂S₆ (CCPS/CIPS) heterostructure composed of ferroelectric (FE) CuInP₂S₆ and multiferroic CuCrP₂S₆. It is shown that CCPS-P↓/CIPS-P↓ is a ferromagnetic (FM) half metal, with the band alignment of type II in the spin-down channel, while for CCPS-P↑/CIPS-P↑, CCPS-P↑/CIPS-P↓, and CCPS-P↓/CIPS-P↑, they are all FM semiconductors with type II band alignment. Moreover, the electronic properties of CCPS/CIPS can be changed under biaxial strains; that is, CCPS-P↓/CIPS-P↓ can change from FM half metal to FM semiconductor, and CCPS-P↑/CIPS-P↑, CCPS-P↑/CIPS-P↓, and CCPS-P↓/CIPS-P↑ have shrinking band gaps in both spin channels under biaxial strains. Such characteristics suggest CCPS/CIPS heterostructure can be potential nonvolatile memory device materials.