中国物理B ›› 2016, Vol. 25 ›› Issue (7): 78102-078102.doi: 10.1088/1674-1056/25/7/078102

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Tunable thermoelectric properties in bended graphene nanoribbons

Chang-Ning Pan(潘长宁), Jun He(何军), Mao-Fa Fang(方卯发)   

  1. 1 School of Science, Hunan University of Technology, Zhuzhou 412008, China;
    2 Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education and Department of Physics, Hunan Normal University, Changsha 410081, China
  • 收稿日期:2016-02-01 修回日期:2016-03-25 出版日期:2016-07-05 发布日期:2016-07-05
  • 通讯作者: Jun He E-mail:hejun@hnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 61401153) and the Natural Science Foundation of Hunan Province, China (Grant Nos. 2015JJ2050 and 14JJ3126).

Tunable thermoelectric properties in bended graphene nanoribbons

Chang-Ning Pan(潘长宁)1, Jun He(何军)1, Mao-Fa Fang(方卯发)2   

  1. 1 School of Science, Hunan University of Technology, Zhuzhou 412008, China;
    2 Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education and Department of Physics, Hunan Normal University, Changsha 410081, China
  • Received:2016-02-01 Revised:2016-03-25 Online:2016-07-05 Published:2016-07-05
  • Contact: Jun He E-mail:hejun@hnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 61401153) and the Natural Science Foundation of Hunan Province, China (Grant Nos. 2015JJ2050 and 14JJ3126).

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摘要： The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic-semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quantum interference effect occurs in the metallic-metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZT\max (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene.

关键词: graphene nanoribbons, thermoelectric properties, quantum interference effect

Abstract: The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic-semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quantum interference effect occurs in the metallic-metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZT\max (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene.

Key words: graphene nanoribbons, thermoelectric properties, quantum interference effect

中图分类号:  (Carbon/carbon-based materials)

  • 81.05.U-
73.63.-b (Electronic transport in nanoscale materials and structures) 72.20.Pa (Thermoelectric and thermomagnetic effects)