中国物理B ›› 2019, Vol. 28 ›› Issue (4): 46803-046803.doi: 10.1088/1674-1056/28/4/046803

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Band engineering of B2H2 nanoribbons

Bao Lei(雷宝), Yu-Yang Zhang(张余洋), Shi-Xuan Du(杜世萱)   

  1. 1 Institute of Physics, Chinese Academy of Sciences(CAS), Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100190, China;
    3 CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2019-01-17 修回日期:2019-02-18 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: Shi-Xuan Du E-mail:sxdu@iphy.ac.cn

Band engineering of B2H2 nanoribbons

Bao Lei(雷宝)1,2, Yu-Yang Zhang(张余洋)1,2,3, Shi-Xuan Du(杜世萱)1,2,3   

  1. 1 Institute of Physics, Chinese Academy of Sciences(CAS), Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100190, China;
    3 CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2019-01-17 Revised:2019-02-18 Online:2019-04-05 Published:2019-04-05
  • Contact: Shi-Xuan Du E-mail:sxdu@iphy.ac.cn

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摘要：

Freestanding honeycomb borophene is unstable due to the electron-deficiency of boron atoms. B2H2 monolayer, a typical borophene hydride, has been predicted to be structurally stable and attracts great attention. Here, we investigate the electronic structures of B2H2 nanoribbons. Based on first-principles calculations, we have found that all narrow armchair nanoribbons with and without mirror symmetry (ANR-s and ANR-as, respectively) are semiconducting. The energy gap has a relation with the width of the ribbon. When the ribbon is getting wider, the gap disappears. The zigzag ribbons without mirror symmetry (ZNR-as) have the same trend. But the zigzag ribbons with mirror symmetry (ZNR-s) are always metallic. We have also found that the metallic ANR-as and ZNR-s can be switched to semiconducting by applying a tensile strain along the nanoribbon. A gap of 1.10 eV is opened under 16% strain for the 11.0-Å ANR-as. Structural stability under such a large strain has also been confirmed. The flexible band tunability of B2H2 nanoribbon increases its possibility of potential applications in nanodevices.

关键词: borophene hydride nanoribbons, band engineering, first-principles calculations, strain

Abstract:

Freestanding honeycomb borophene is unstable due to the electron-deficiency of boron atoms. B2H2 monolayer, a typical borophene hydride, has been predicted to be structurally stable and attracts great attention. Here, we investigate the electronic structures of B2H2 nanoribbons. Based on first-principles calculations, we have found that all narrow armchair nanoribbons with and without mirror symmetry (ANR-s and ANR-as, respectively) are semiconducting. The energy gap has a relation with the width of the ribbon. When the ribbon is getting wider, the gap disappears. The zigzag ribbons without mirror symmetry (ZNR-as) have the same trend. But the zigzag ribbons with mirror symmetry (ZNR-s) are always metallic. We have also found that the metallic ANR-as and ZNR-s can be switched to semiconducting by applying a tensile strain along the nanoribbon. A gap of 1.10 eV is opened under 16% strain for the 11.0-Å ANR-as. Structural stability under such a large strain has also been confirmed. The flexible band tunability of B2H2 nanoribbon increases its possibility of potential applications in nanodevices.

Key words: borophene hydride nanoribbons, band engineering, first-principles calculations, strain

中图分类号:  (Mechanical properties; surface strains)

  • 68.35.Gy
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.20.Ps (Other inorganic compounds) 68.60.Wm (Other nonelectronic physical properties)