Stacking and tuning effects on magneto-electronic and electric contact features for arsenene/Fe3GeTe2 van der Waals heterostructure

Abstract

Recently, experimentally available Fe3GeTe2 (FGT) monolayer has attracted tremendous research interest due to its long-range ferromagnetic (FM) order. Here, we systematically study the magneto-electronic and electric contact properties of FGT-based van der Waals (vdW) heterostructures integrated by arsenene (As) with multiple stacking patterns. The low binding energy (−117.69 to −52.69 meV atom−1) proves their highly geometric stability, and the high magnetized energy (91.61–213.61 meV/unit cell) and magnetic exchange energy (64.53–84.43 meV/unit cell) provide a strong evidence for magnetism stability. Particularly, the magnetic proximity exchange effect as well as spin transfer and spin rearrangement can enhance the FM coupling in heterostructures, so that the highest Curie temperature T C = 173.93 K is achieved, being 19.73% higher than isolated FGT. Meanwhile, the arsenene is magnetized as well. In particular, metal-induced gap states appear in band gap of original As monolayer. Besides, metal-semiconductor contact performance is improved in constructed heterostructures by lowering electronic Schottky barrier height to nearly obtain Ohmic contact. Magnetic exchange energy rises further to improve magnetic stability with the interlayer spacing narrowed, and T C is increased up to 184.80 K, an increase of 27.21% compared to FGT monolayer. Being attributed to the proximity exchange effect strengthened with a shrunk interlayer spacing, and the electric contact behavior is also boosted further by this compressive strain to realize high-performance electric junction. Our findings provide a new route to extend the applications of FGT by constructing suitable vdW heterostructures.