中国物理B ›› 2016, Vol. 25 ›› Issue (11): 117309-117309.doi: 10.1088/1674-1056/25/11/117309

所属专题： TOPICAL REVIEW — Topological electronic states

• TOPICAL REVIEW—Topological electronic states • 上一篇    下一篇

Thermoelectric effects and topological insulators

Yong Xu(徐勇)   

  1. 1 State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing 100084, China;
    3 RIKEN Center for Emergent Matter Science(CEMS), Wako, Saitama 351-0198, Japan
  • 收稿日期:2016-06-02 修回日期:2016-07-03 出版日期:2016-11-05 发布日期:2016-11-05
  • 通讯作者: Yong Xu E-mail:yongxu@mail.tsinghua.edu.cn
  • 基金资助:

    Project supported by the National Thousand-Young-Talents Program, China and Tsinghua University Initiative Scientific Research Program, China.

Thermoelectric effects and topological insulators

Yong Xu(徐勇)1,2,3   

  1. 1 State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing 100084, China;
    3 RIKEN Center for Emergent Matter Science(CEMS), Wako, Saitama 351-0198, Japan
  • Received:2016-06-02 Revised:2016-07-03 Online:2016-11-05 Published:2016-11-05
  • Contact: Yong Xu E-mail:yongxu@mail.tsinghua.edu.cn
  • Supported by:

    Project supported by the National Thousand-Young-Talents Program, China and Tsinghua University Initiative Scientific Research Program, China.

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摘要：

The recent discovery of topological insulators (TIs) offers new opportunities for the development of thermoelectrics, because many TIs (like Bi2Te3) are excellent thermoelectric (TE) materials. In this review, we will first describe the general TE properties of TIs and show that the coexistence of the bulk and boundary states in TIs introduces unusual TE properties, including strong size effects and an anomalous Seebeck effect. Importantly, the TE figure of merit zT of TIs is no longer an intrinsic property, but depends strongly on the geometric size. The geometric parameters of two-dimensional TIs can be tuned to enhance zT to be significantly greater than 1. Then a few proof-of-principle experiments on three-dimensional TIs will be discussed, which observed unconventional TE phenomena that are closely related to the topological nature of the materials. However, current experiments indicate that the metallic surface states, if their advantage of high mobility is not fully utilized, would be detrimental to TE performance. Finally, we provide an outlook for future work on topological materials, which offers great possibilities to discover exotic TE effects and may lead to significant breakthroughs in improving zT.

关键词: thermoelectric effect, topological insulator, surface states

Abstract:

The recent discovery of topological insulators (TIs) offers new opportunities for the development of thermoelectrics, because many TIs (like Bi2Te3) are excellent thermoelectric (TE) materials. In this review, we will first describe the general TE properties of TIs and show that the coexistence of the bulk and boundary states in TIs introduces unusual TE properties, including strong size effects and an anomalous Seebeck effect. Importantly, the TE figure of merit zT of TIs is no longer an intrinsic property, but depends strongly on the geometric size. The geometric parameters of two-dimensional TIs can be tuned to enhance zT to be significantly greater than 1. Then a few proof-of-principle experiments on three-dimensional TIs will be discussed, which observed unconventional TE phenomena that are closely related to the topological nature of the materials. However, current experiments indicate that the metallic surface states, if their advantage of high mobility is not fully utilized, would be detrimental to TE performance. Finally, we provide an outlook for future work on topological materials, which offers great possibilities to discover exotic TE effects and may lead to significant breakthroughs in improving zT.

Key words: thermoelectric effect, topological insulator, surface states

中图分类号:  (Thermoelectric effects)

  • 73.50.Lw
72.20.Pa (Thermoelectric and thermomagnetic effects) 71.90.+q (Other topics in electronic structure) 73.23.-b (Electronic transport in mesoscopic systems)