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.

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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