Multiferroic tunnel junctions (MFTJs) composed of ferroelectricity and ferromagnetism have attractive prospects in memory and computing device applications due to their low power consumption and nonvolatile switching. However, achieving both spin filter effect (SFE) and excellent tunnel electroresistance (TER) effect in two-dimensional (2D) van der Waals (vdW) MFTJs still remain challenging. Herein, using first-principles calculations, we investigate interface design for electronic and transport properties of asymmetric 2D vdW MFTJs that consist of CrI₃, graphene, and ferroelectric Sc₂CO₂ (containing Sc–P↑ and Sc–P↓ states). We find that such CrI₃/Sc–P↑/graphene MFTJs exhibit p-type Ohmic contact for Sc–P↑/graphene and SFE for CrI₃/Sc–P↑ due to the transformation of CrI₃ from intrinsic semiconductor to half-metal. Simultaneously, the Dirac point of graphene at the Fermi energy has a big shift about 0.95 eV with the polarization reversal, suggesting that there is a giant barrier modulation. Moreover, the huge TER ratio about 1.7×10⁵% was also discovered by transport calculations. Our results provide an avenue for the design of future 2D vdW MFTJs.

由铁电和铁磁性组成的多铁隧道结（MFTJ）由于其低功耗和非易失性开关，在存储器和计算设备应用中具有诱人的前景。然而，在二维 (2D) 范德华 (vdW) MFTJ 中同时实现自旋滤波器效应 (SFE) 和出色的隧道电阻 (TER) 效应仍然具有挑战性。在此，我们使用第一性原理计算，研究了由 CrI₃、石墨烯和铁电 Sc₂CO₂（包含-P↑ 和ScP↓ 态）MFTJ我们发现这样的 CrI ₃由于 CrI ₃从本征半导体转变为半金属， /Sc–P↑/石墨烯MFTJ表现出 Sc–P↑/石墨烯的p型欧姆接触和CrI ₃ / Sc –P↑ 的SFE 。同时，石墨烯在费米能级处的狄拉克点随着极化反转发生了约0.95 eV的大位移，表明存在巨大的势垒调制。此外，通过输运计算还发现了约1.7×10 ^{5 %的巨大TER比率。}我们的结果为未来 2D vdW MFTJ 的设计提供了一条途径。