中国物理B ›› 2021, Vol. 30 ›› Issue (5): 57101-057101.doi: 10.1088/1674-1056/abddac

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First-principles investigation of the valley and electrical properties of carbon-doped α-graphyne-like BN sheet

Bo Chen(陈波), Xiang-Qian Li(李向前), Lin Xue(薛林), Yan Han(韩燕), Zhi Yang(杨致), and Long-Long Zhang(张龙龙)   

  1. College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
  • 收稿日期:2020-12-17 修回日期:2021-01-14 接受日期:2021-01-20 出版日期:2021-05-14 发布日期:2021-05-14
  • 通讯作者: Bo Chen E-mail:chenbo@tyut.edu.cn
  • 基金资助:
    Project supported by the Special Foundation for Theoretical Physics Research Program of China (Grant No. 11847065) and the Natural Science Foundation of Shanxi Province, China (Grant No. 201901D211115).

First-principles investigation of the valley and electrical properties of carbon-doped α-graphyne-like BN sheet

Bo Chen(陈波), Xiang-Qian Li(李向前), Lin Xue(薛林), Yan Han(韩燕), Zhi Yang(杨致), and Long-Long Zhang(张龙龙)   

  1. College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2020-12-17 Revised:2021-01-14 Accepted:2021-01-20 Online:2021-05-14 Published:2021-05-14
  • Contact: Bo Chen E-mail:chenbo@tyut.edu.cn
  • Supported by:
    Project supported by the Special Foundation for Theoretical Physics Research Program of China (Grant No. 11847065) and the Natural Science Foundation of Shanxi Province, China (Grant No. 201901D211115).

摘要: Based on ab initio density functional theory calculations, we demonstrate that two carbon-doped boron nitride analog of α-graphyne structures, B3C2N3 and BC6N monolayers, are two-dimensional direct wide band gap semiconductors, and there are two inequivalent valleys in the vicinities of the vertices of their hexagonal Brillouin zones. Besides, B3C2N3 and BC6N monolayers exhibit relatively high carrier mobilities, and their direct band gap feature is robust against the biaxial strain. More importantly, the energetically most favorable B3C2N3 and BC6N bilayers also have direct wide band gaps, and valley polarization could be achieved by optical helicity. Finally, we show that BC6N monolayer might have high efficiency in photo-splitting reactions of water, and a vertical van der Waals heterostructure with a type-Ⅱ energy band alignment could be designed using B3C2N3 and BC6N monolayers. All the above-mentioned characteristics make B3C2N3 and BC6N monolayers, bilayers, and their heterostructures recommendable candidates for applications in valleytronic devices, metal-free photocatalysts, and photovoltaic cells.

关键词: first-principles calculations, α-graphyne like structures, valleytronic materials, wide band gap semiconductors

Abstract: Based on ab initio density functional theory calculations, we demonstrate that two carbon-doped boron nitride analog of α-graphyne structures, B3C2N3 and BC6N monolayers, are two-dimensional direct wide band gap semiconductors, and there are two inequivalent valleys in the vicinities of the vertices of their hexagonal Brillouin zones. Besides, B3C2N3 and BC6N monolayers exhibit relatively high carrier mobilities, and their direct band gap feature is robust against the biaxial strain. More importantly, the energetically most favorable B3C2N3 and BC6N bilayers also have direct wide band gaps, and valley polarization could be achieved by optical helicity. Finally, we show that BC6N monolayer might have high efficiency in photo-splitting reactions of water, and a vertical van der Waals heterostructure with a type-Ⅱ energy band alignment could be designed using B3C2N3 and BC6N monolayers. All the above-mentioned characteristics make B3C2N3 and BC6N monolayers, bilayers, and their heterostructures recommendable candidates for applications in valleytronic devices, metal-free photocatalysts, and photovoltaic cells.

Key words: first-principles calculations, α-graphyne like structures, valleytronic materials, wide band gap semiconductors

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

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