Enhancing the electronic and optical properties of the metal/semiconductor NbS₂/BSe nanoheterostructure towards...

Metal-semiconductor (M-S) contacts play a vital role in advanced applications, serving as crucial components in ultracompact devices and exerting a significant impact on overall device performance. Here, in this work, we design a M-S nanoheterostructure between a metallic NbS₂ monolayer and a semiconducting BSe monolayer using first-principles prediction. The stability of such an M-S nanoheterostructure is verified and its electronic and optical properties are also considered. Our results indicate that the NbS₂/BSe nanoheterostructure is structurally, mechanically and thermally stable. The formation of the NbS₂/BSe heterostructure leads to the generation of a Schottky contact with the Schottky barrier ranging from 0.36 to 0.51 eV, depending on the stacking configurations. In addition, the optical absorption coefficient of the NbS₂/BSe heterostructure can reach up to 5 × 10⁵ cm^-1 at a photon energy of about 5 eV, which is still greater than that in the constituent NbS₂ and BSe monolayers. This finding suggests that the formation of the M-S NbS₂/BSe heterostructure gives rise to an enhancement in the optical absorption of both NbS₂ and BSe monolayers. Notably, the tunneling probability and the contact tunneling-specific resistivity at the interface of the NbS₂/BSe heterostructure are low, indicating its applicability in emerging nanoelectronic devices, such as Schottky diodes and field-effect transistors. Our findings offer valuable insights for the practical utilization of electronic devices based on the NbS₂/BSe heterostructure.