1. Tuning electronic properties of the S 2 /graphene heterojunction by strains from density functional theory
- Author
-
Jun-Hui Lei, Jian-Guo Lin, and Xiu-Feng Wang
- Subjects
Materials science ,Condensed matter physics ,Band gap ,Graphene ,Schottky barrier ,General Physics and Astronomy ,Heterojunction ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,law ,0103 physical sciences ,Monolayer ,Field-effect transistor ,Direct and indirect band gaps ,Density functional theory ,010306 general physics ,0210 nano-technology - Abstract
Based on the density functional calculations, the structural and electronic properties of the WS2/graphene heterojunction under different strains are investigated. The calculated results show that unlike the free mono-layer WS2, the monolayer WS2 in the equilibrium WS2/graphene heterojunctionis characterized by indirect band gap due to the weak van der Waals interaction. The height of the schottky barrier for the WS2/graphene heterojunction is 0.13 eV, which is lower than the conventional metal/MoS2 contact. Moreover, the band properties and height of schottky barrier for WS2/graphene heterojunction can be tuned by strain. It is found that the height of the schottky barrier can be tuned to be near zero under an in-plane compressive strain, and the band gap of the WS2 in the heterojunction is turned into a direct band gap from the indirect band gap with the increasing schottky barrier height under an in-plane tensile strain. Our calculation results may provide a potential guidance for designing and fabricating the WS2-based field effect transistors.
- Published
- 2017