中国物理B ›› 2017, Vol. 26 ›› Issue (12): 127101-127101.doi: 10.1088/1674-1056/26/12/127101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Tuning electronic properties of the S2/graphene heterojunction by strains from density functional theory

Jun-Hui Lei(雷军辉), Xiu-Fen Wang(王秀峰), Jian-Guo Lin(林建国)   

  1. Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China
  • 收稿日期:2017-07-16 修回日期:2017-08-24 出版日期:2017-12-05 发布日期:2017-12-05
  • 通讯作者: Jian-Guo Lin E-mail:lin_j_g@xtu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11202178).

Tuning electronic properties of the S2/graphene heterojunction by strains from density functional theory

Jun-Hui Lei(雷军辉), Xiu-Fen Wang(王秀峰), Jian-Guo Lin(林建国)   

  1. Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China
  • Received:2017-07-16 Revised:2017-08-24 Online:2017-12-05 Published:2017-12-05
  • Contact: Jian-Guo Lin E-mail:lin_j_g@xtu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11202178).

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摘要： 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.

关键词: WS2/graphene heterojunction, density functional theory (DFT), Schottky barrier, direct/indirect band gap

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.

Key words: WS2/graphene heterojunction, density functional theory (DFT), Schottky barrier, direct/indirect band gap

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
71.20.-b (Electron density of states and band structure of crystalline solids) 82.65.+r (Surface and interface chemistry; heterogeneous catalysis at surfaces) 68.47.Fg (Semiconductor surfaces)