Electronic structure and magnetic properties of two-dimensional h-BN/Janus 2H-VSeX (X = S, Te) van der Waals heterostructures

Highlights: • h-BN/2H-VSeX heterostructures have direct band gap with in-plane magnetic anisotropy. • By considering the spin-orbit coupling, the valley splitting appears in the heterostructures. • Dzyaloshinskii-Moriya interaction has the opposite sign in Janus 2H-VSSe and 2H-VSeTe. • Electronic structure and magnetic properties of h-BN/VSeX heterostructures are tunable. Two-dimensional (2D) van der Waals (vdW) heterostructures based on intrinsic magnetic monolayers with unique properties have attracted much attention due to the potential applications in nanoelectronics and spintronics. However, 2D Janus monolayer based vdW heterostructures have not been investigated in details. Here, the electronic structure and magnetic properties of 2D h-BN/2H-VSeX (X = S, Te) vdW heterostructures are studied by first-principles calculations. The h-BN/2H-VSeX heterostructures are direct band-gap semiconductors with in-plane magnetic anisotropy (IMA). By considering the spin-orbit coupling, the valley splitting appears, where the intrinsic valley splitting has the potential applications in valleytronics. The most stable atomic arrangement of the h-BN/2H-VSeX (X = S, Te) heterostructures depends on stacking patterns, where the band gap and IMA can be tailored by combination modes. The magnetic anisotropy energy mainly comes from the hybridization between V d and Se/Te p orbitals. Additionally, the Dzyaloshinskii-Moriya interaction has the opposite sign in Janus 2H-VSSe and 2H-VSeTe heterostructures, which mainly comes from Se and Te atoms. The theoretical results show that the h-BN/Janus 2H-VSeX heterostructures have the potential applications in novel spintronic devices.