Photoemission study of the electronic structure of valence band convergent SnSe

ORAL

Abstract

IV-VI semiconductor SnSe has been known as the material with record high thermoelectric performance. The multiple close-to-degenerate (or “convergent”) valence bands in the electronic band structure has been one of the key factors contributing to the high power factor and thus figure of merit in the SnSe single crystal. To date, there have been primarily theoretical calculations of this particular electronic band structure. In this paper, however, using angle-resolved photoemission spectroscopy, we perform a systematic investigation of the electronic structure of SnSe. We directly observe three predicted hole bands with small energy differences between their band tops and relatively small in-plane effective masses, in good agreement with the ab initio calculations and critical for the enhancement of the Seebeck coefficient while keeping high electrical conductivity. Our results reveal the complete band structure of SnSe and help to provide a deeper understanding of the electronic origin of the excellent thermoelectric performances in SnSe.

*The National Natural Science Foundation of China (Grant No. 11674229).
The National Natural Science Foundation of China (Grant No. 11227902)
Science and Technology Commission of Shanghai Municipality (Grant No. 14520722100).

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Presenters

  • Chengwei Wang

    • Shanghai Institute of Microsystem and Information Technology

Authors

  • Chengwei Wang

    • Shanghai Institute of Microsystem and Information Technology

  • Yunyouyou Xia

    • ShanghaiTech University

  • Zhen Tian

    • ShanghaiTech University

  • Juan Jiang

    • ShanghaiTech University
    • Advanced Light Source
    • School of Physical Science and Technology , Shanghaitech University

  • Binhan Li

    • ShanghaiTech University

  • Shengtao Cui

    • ShanghaiTech University

  • Haifeng Yang

    • ShanghaiTech University
    • School of Physical Science and Technology, ShanghaiTech University

  • Aiji Liang

    • ShanghaiTech University

  • Xiaoyi Zhan

    • Shanghai Institute of Microsystem and Information Technology

  • Guanghao Hong

    • ShanghaiTech University

  • Shuai Liu

    • ShanghaiTech University

  • Cheng Chen

    • University of Oxford
    • Department of Physics, University of Oxford

  • Meixiao Wang

    • ShanghaiTech University
    • Physics and Astronomy, Shanghai Jiao Tong Univ
    • Shanghai Tech University

  • Lexian Yang

    • Tsinghua University

  • Zhi Liu

    • Shanghai Institute of Microsystem and Information Technology
    • SIMIT,CAS
    • SIMIT

  • Qixi Mi

    • ShanghaiTech University

  • Gang Li

    • ShanghaiTech University
    • School of Physical Science and Technology, ShanghaiTech University

  • Jiaming Xue

    • ShanghaiTech University

  • Zhongkai Liu

    • ShanghaiTech University
    • School of Physical Science and Technology , Shanghaitech University
    • School of Physical Science and Technology, ShanghaiTech University

  • Yulin Chen

    • Physics department, University of Oxford
    • University of Oxford
    • Oxford Unv.
    • physics, university of oxford
    • Department of Physics, University of Oxford
    • Condensed Matter Physics, University of Oxford