Theoretical Analysis of a 2D Metallic/Semiconducting Transition-Metal Dichalcogenide NbS2//WSe2 Hybrid Interface

A first-principles theoretical study of a monolayer-thick lateral heterostructure (LH) joining two different transition metal dichalcogenides, NbS2 and WSe2, is reported. The NbS2//WSe2 LH can be considered a prototypical example of a metal (NbS2)/semiconductor (WSe2) 2D hybrid heterojunction. First, realistic atomistic models of the NbS2//WSe2 LH are generated and validated, its band structure is derived, and it is subjected to a fragment decomposition and electrostatic potential analysis to extract a simple but quantitative model of this interfacial system. Stoichiometric fluctuations models are also investigated and found not to alter the qualitative picture. Then, electron transport simulations are conducted and they are analyzed via band alignment analysis. It is concluded that the NbS2//WSe2 LH appears as a robust seamless in-plane 2D modular junction for potential use in optoelectronic devices going beyond the present miniaturization technology.