A two-dimensional MoS 2 /C 3 N broken-gap heterostructure, a first principles study.

van der Waals (vdW) heterojunctions are of interest in two-dimensional electronic and optoelectronic devices. In this work, first-principles calculations were used to study the atomic and electronic properties of the MoS 2 /C 3 N vdW heterojunction. The results show that there is no overlap of the band gaps for the MoS 2 and C 3 N monolayers in the heterojunction, indicating the MoS 2 /C 3 N vdW heterostructure has a type III alignment. The MoS 2 /C 3 N vdW heterostructure is a broken-gap heterojunction. The effects of biaxial strain and external electric field on the band structure of the vdW heterostructure were also investigated. The alignment type cannot be changed, but the band overlap can be tuned. The present work reveals that the MoS 2 /C 3 N heterostructures are quite favorable for applications in tunneling devices based on the broken-gap heterostructures.