中国物理B ›› 2019, Vol. 28 ›› Issue (7): 77106-077106.doi: 10.1088/1674-1056/28/7/077106

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

A simple rule for finding Dirac cones in bilayered perovskites

Xuejiao Chen(陈雪娇), Lei Liu(刘雷), Dezhen Shen(申德振)   

  1. 1 State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • 收稿日期:2019-05-31 出版日期:2019-07-05 发布日期:2019-07-05
  • 通讯作者: Lei Liu, Dezhen Shen E-mail:liulei@ciomp.ac.cn;shendz@ciomp.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 61525404).

A simple rule for finding Dirac cones in bilayered perovskites

Xuejiao Chen(陈雪娇)1,2, Lei Liu(刘雷)1, Dezhen Shen(申德振)1   

  1. 1 State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-05-31 Online:2019-07-05 Published:2019-07-05
  • Contact: Lei Liu, Dezhen Shen E-mail:liulei@ciomp.ac.cn;shendz@ciomp.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 61525404).

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摘要：

A simple rule for finding Dirac cone electronic states in solids is proposed, which is neglecting those lattice atoms inert to particular electronic bands, and pursuing the two-dimensional (2D) graphene-like quasi-atom lattices with s- and p-bindings by considering the equivalent atom groups in the unit cell as quasi-atoms. Taking CsPbBr3 and Cs3Bi2Br9 bilayers as examples, we prove the effectiveness and generality of this rule with the density functional theory (DFT) calculations. We demonstrate that both bilayers have Dirac cones around the Fermi level and reveal that their corresponding Fermi velocities can reach as high as~0.2×106 m/s. This makes these new 2D layered materials very promising in making new ultra-fast ionic electronic devices.

关键词: Dirac cone, perovskites, graphene, density functional theory

Abstract:

A simple rule for finding Dirac cone electronic states in solids is proposed, which is neglecting those lattice atoms inert to particular electronic bands, and pursuing the two-dimensional (2D) graphene-like quasi-atom lattices with s- and p-bindings by considering the equivalent atom groups in the unit cell as quasi-atoms. Taking CsPbBr3 and Cs3Bi2Br9 bilayers as examples, we prove the effectiveness and generality of this rule with the density functional theory (DFT) calculations. We demonstrate that both bilayers have Dirac cones around the Fermi level and reveal that their corresponding Fermi velocities can reach as high as~0.2×106 m/s. This makes these new 2D layered materials very promising in making new ultra-fast ionic electronic devices.

Key words: Dirac cone, perovskites, graphene, density functional theory

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

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73.22.Pr (Electronic structure of graphene)