Band structures and transport properties of broken-gap heterostructures: 2D C3N/MX case

Building van der Waals heterostructures (vdWHs) is an effective method to broaden two-dimensional (2D) material applications in multifunctional devices. However, few broken-gap vdWHs are realized, which limit 2D materials development in the tunnel field-effect transistors. Here, based on the density functional theory, we theoretically design the stable 2D C3N/MX(M = Ga, In; X = S, Se, Te) vdWHs, where the band-to-band tunneling (BTBT) exists due to the broken-gap band alignment. The negative electric field expands the tunneling window, while multifunctional band alignment can be realized under positive electric field. Moreover, the I-V curves present the obvious negative differential resistance behavior. This work provides the understanding of physical mechanism and possible applications for 2D broken-gap vdWHs.

Automated summary

Building van der Waals heterostructures (vdWHs) is an effective method to broaden two-dimensional material applications. However, few broken-gap vdWHs have been realized, limiting the development of 2D materials in tunnel field-effect transistors. In this study, stable 2D C3N/MX vdWHs were theoretically designed using density functional theory, and the band-to-band tunneling and multifunctional band alignment were explored.