中国物理B ›› 2021, Vol. 30 ›› Issue (7): 77405-077405.doi: 10.1088/1674-1056/abe115

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Two-dimensional square-Au2S monolayer: A promising thermoelectric material with ultralow lattice thermal conductivity and high power factor

Wei Zhang(张伟)1, Xiao-Qiang Zhang(张晓强)1, Lei Liu(刘蕾)1,†, Zhao-Qi Wang(王朝棋)2,‡, and Zhi-Guo Li(李治国)3,§   

  1. 1 School of Science, Southwest University of Science and Technology, Mianyang 621010, China;
    2 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    3 Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Mianyang 610064, China
  • 收稿日期:2020-11-11 修回日期:2021-01-14 接受日期:2021-01-29 出版日期:2021-06-22 发布日期:2021-06-30
  • 通讯作者: Lei Liu, Zhao-Qi Wang, Zhi-Guo Li E-mail:lei_liuchn@163.com;zhqwangsc@foxmail.com;zhiguo_li@foxmail.com
  • 基金资助:
    Project supported by the Doctoral Research Fund of Southwest University of Science and Technology (Grant No. 21zx7113) and the National Natural Science Foundation of China (Grant Nos. 11804284 and 11802280).

Two-dimensional square-Au2S monolayer: A promising thermoelectric material with ultralow lattice thermal conductivity and high power factor

Wei Zhang(张伟)1, Xiao-Qiang Zhang(张晓强)1, Lei Liu(刘蕾)1,†, Zhao-Qi Wang(王朝棋)2,‡, and Zhi-Guo Li(李治国)3,§   

  1. 1 School of Science, Southwest University of Science and Technology, Mianyang 621010, China;
    2 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    3 Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Mianyang 610064, China
  • Received:2020-11-11 Revised:2021-01-14 Accepted:2021-01-29 Online:2021-06-22 Published:2021-06-30
  • Contact: Lei Liu, Zhao-Qi Wang, Zhi-Guo Li E-mail:lei_liuchn@163.com;zhqwangsc@foxmail.com;zhiguo_li@foxmail.com
  • Supported by:
    Project supported by the Doctoral Research Fund of Southwest University of Science and Technology (Grant No. 21zx7113) and the National Natural Science Foundation of China (Grant Nos. 11804284 and 11802280).

摘要: The search for new two-dimensional (2D) harvesting materials that directly convert (waste) heat into electricity has received increasing attention. In this work, thermoelectric (TE) properties of monolayer square-Au2S are accurately predicted using a parameter-free ab initio Boltzmann transport formalism with fully considering the spin-orbit coupling (SOC), electron-phonon interactions (EPIs), and phonon-phonon scattering. It is found that the square-Au2S monolayer is a promising room-temperature TE material with an n-type (p-type) figure of merit ZT = 2.2 (1.5) and an unexpected high n-type ZT = 3.8 can be obtained at 600 K. The excellent TE performance of monolayer square-Au2S can be attributed to the ultralow lattice thermal conductivity originating from the strong anharmonic phonon scattering and high power factor due to the highly dispersive band edges around the Fermi level. Additionally, our analyses demonstrate that the explicit treatments of EPIs and SOC are highly important in predicting the TE properties of monolayer square-Au2S. The present findings will stimulate further the experimental fabrication of monolayer square-Au2S-based TE materials and offer an in-depth insight into the effect of SOC and EPIs on TE transport properties.

关键词: first-principles calculations, electron-phonon interactions, lattice thermal conductivity, thermoelectric properties

Abstract: The search for new two-dimensional (2D) harvesting materials that directly convert (waste) heat into electricity has received increasing attention. In this work, thermoelectric (TE) properties of monolayer square-Au2S are accurately predicted using a parameter-free ab initio Boltzmann transport formalism with fully considering the spin-orbit coupling (SOC), electron-phonon interactions (EPIs), and phonon-phonon scattering. It is found that the square-Au2S monolayer is a promising room-temperature TE material with an n-type (p-type) figure of merit ZT = 2.2 (1.5) and an unexpected high n-type ZT = 3.8 can be obtained at 600 K. The excellent TE performance of monolayer square-Au2S can be attributed to the ultralow lattice thermal conductivity originating from the strong anharmonic phonon scattering and high power factor due to the highly dispersive band edges around the Fermi level. Additionally, our analyses demonstrate that the explicit treatments of EPIs and SOC are highly important in predicting the TE properties of monolayer square-Au2S. The present findings will stimulate further the experimental fabrication of monolayer square-Au2S-based TE materials and offer an in-depth insight into the effect of SOC and EPIs on TE transport properties.

Key words: first-principles calculations, electron-phonon interactions, lattice thermal conductivity, thermoelectric properties

中图分类号:  (Superconducting films and low-dimensional structures)

  • 74.78.-w
74.25.fg (Thermoelectric effects) 63.22.-m (Phonons or vibrational states in low-dimensional structures and nanoscale materials)