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In this work, strain and interfacial defect tailored electronic structures of h-BN/WSe₂ heterostructure are investigated systematically. The results show that the WSe₂/h-BN heterostructure is a direct bandgap semiconductor (1.211eV) with type-I band alignment compared with the isolated h-BN and WSe₂ monolayers. Applying the in-plane strain can well adjust the electronic structure of heterostructure, resulting in a transition from indirect to direct bandgap at the strain of −2% for the h-BN/WSe₂ heterostructures. The bandgap of h-BN/WSe₂ heterostructure monotonically increases at the compressive strains from −6% to −2%, whereas decreases at the tensile strains from 0% to 8%. In addition, introducing of vacancy defects and n- or p-type doping can effectively alter the band alignment of heterostructure. When the N and B vacancies or C doping are introduced in the h-BN layer, a significant transform from type-I to type-II band alignment is observed. These results suggest the h-BN/WSe₂ heterostructure becomes a good candidate for the application of optoelectronics and nanoelectronics devices.

In this work, the effects of magnetic proximity coupling on electronic structures, valley polarization and magneto-crystal anisotropy of VI₃/WSe₂ heterostructure are studied in detail based on density functional theory. The results show that the spin-valley polarization characters of WSe₂ monolayer can be induced by the proximity effect of ferromagnetic VI₃ monolayer. Based on the effective Hamiltonian $k\cdot p$ model, a large valley polarization of 8.7meV is observed, which is mainly contributed by the SOC effect and not magnetic exchange field. Meanwhile, the magneto-crystal anisotropy of VI₃ layer is also obviously altered from the [100] to [001] magnetic axis compared to the isolated VI₃ monolayer. The reduction in the interlayer space strengths the W–V atomic coupling, resulting in a significant increase in the spin and valley polarization. Compression strain shows weakening effect on the valley polarization, while the tensile strain largely enhances the valley polarization of VI₃/WSe₂ heterostructure, which can reach the maximum value of 29.1meV at the tensile strain of 8%. The V spin direction ($\theta$) has significant effect on valley polarization of WSe₂ layer, which is positively correlated with the magnetization strength of V atom in the vertical direction. Furthermore, constructing the VI₃/WSe₂/VI₃ sandwich heterostructure can induce a larger valley polarization, which can reach a maximum value of 32.4meV. These results indicate that the VI₃/WSe₂ heterostructure is a potential candidate for valleytronics.