中国物理B ›› 2021, Vol. 30 ›› Issue (12): 128401-128401.doi: 10.1088/1674-1056/ac012c

• • 上一篇    下一篇

Excellent thermoelectric performance predicted in Sb2Te with natural superlattice structure

Pei Zhang(张培), Tao Ouyang(欧阳滔), Chao Tang(唐超), Chaoyu He(何朝宇), Jin Li(李金), Chunxiao Zhang(张春小), and Jianxin Zhong(钟建新)   

  1. Hunan Key Laboratory for Micro-Nano Energy Materials & Device and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China
  • 收稿日期:2021-03-02 修回日期:2021-04-30 接受日期:2021-05-14 出版日期:2021-11-15 发布日期:2021-11-15
  • 通讯作者: Tao Ouyang, Jianxin Zhong E-mail:ouyangtao@xtu.edu.cn;jxzhong@xtu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11974300, 11974299, and 11704319), the Natural Science Foundation of Hunan Province, China (Grant No. 2021JJ30645), the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 20K127, 20A503, and 20B582), the Program for Changjiang Scholars and Innovative Research Team in Universities (Grant No. IRT13093), and the Hunan Provincial Innovation Foundation for Postgraduate Students, China (Grant No. CX20200624).

Excellent thermoelectric performance predicted in Sb2Te with natural superlattice structure

Pei Zhang(张培), Tao Ouyang(欧阳滔), Chao Tang(唐超), Chaoyu He(何朝宇), Jin Li(李金), Chunxiao Zhang(张春小), and Jianxin Zhong(钟建新)   

  1. Hunan Key Laboratory for Micro-Nano Energy Materials & Device and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China
  • Received:2021-03-02 Revised:2021-04-30 Accepted:2021-05-14 Online:2021-11-15 Published:2021-11-15
  • Contact: Tao Ouyang, Jianxin Zhong E-mail:ouyangtao@xtu.edu.cn;jxzhong@xtu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11974300, 11974299, and 11704319), the Natural Science Foundation of Hunan Province, China (Grant No. 2021JJ30645), the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 20K127, 20A503, and 20B582), the Program for Changjiang Scholars and Innovative Research Team in Universities (Grant No. IRT13093), and the Hunan Provincial Innovation Foundation for Postgraduate Students, China (Grant No. CX20200624).

摘要: Using first-principles calculations combined with the Boltzmann transport theory, we explore the thermoelectric properties of natural superlattice (SL) structure Sb2Te. The results show that n-type Sb2Te possesses larger Seebeck coefficient of 249.59 (318.87) μV/K than p-type Sb2Te of 219.85 (210.38) μV/K and low lattice thermal conductivity of 1.25 (0.21) W/mK along the in-plane (out-of-plane) direction at 300 K. The excellent electron transport performance is mainly attributed to steeper density of state around the bottom of conduction band. The ultralow lattice thermal conductivity of Sb2Te is mainly caused by low phonon group velocity and strong anharmonicity. Further analysis shows that the decrease of group velocity comes from flatter dispersion curves which are contributed by the Brillouin-zone folding. The strong anharmonicity is mainly due to the presence of lone-pair electrons in Sb2Te. Combining such a high Seebeck coefficient with the low lattice thermal conductivity, maximum n-type thermoelectric figure of merit (ZT) of 1.46 and 1.38 could be achieved along the in-plane and out-of-plane directions at room temperature, which is higher than the reported values of Sb2Te3. The findings presented here provide insight into the transport property of Sb2Te and highlight potential applications of thermoelectric materials at room temperature.

关键词: thermoelectric, superlattice (SL), thermal conductivity, phonons

Abstract: Using first-principles calculations combined with the Boltzmann transport theory, we explore the thermoelectric properties of natural superlattice (SL) structure Sb2Te. The results show that n-type Sb2Te possesses larger Seebeck coefficient of 249.59 (318.87) μV/K than p-type Sb2Te of 219.85 (210.38) μV/K and low lattice thermal conductivity of 1.25 (0.21) W/mK along the in-plane (out-of-plane) direction at 300 K. The excellent electron transport performance is mainly attributed to steeper density of state around the bottom of conduction band. The ultralow lattice thermal conductivity of Sb2Te is mainly caused by low phonon group velocity and strong anharmonicity. Further analysis shows that the decrease of group velocity comes from flatter dispersion curves which are contributed by the Brillouin-zone folding. The strong anharmonicity is mainly due to the presence of lone-pair electrons in Sb2Te. Combining such a high Seebeck coefficient with the low lattice thermal conductivity, maximum n-type thermoelectric figure of merit (ZT) of 1.46 and 1.38 could be achieved along the in-plane and out-of-plane directions at room temperature, which is higher than the reported values of Sb2Te3. The findings presented here provide insight into the transport property of Sb2Te and highlight potential applications of thermoelectric materials at room temperature.

Key words: thermoelectric, superlattice (SL), thermal conductivity, phonons

中图分类号:  (Thermoelectric, electrogasdynamic and other direct energy conversion)

  • 84.60.Rb
73.21.Cd (Superlattices) 65.40.-b (Thermal properties of crystalline solids) 63.20.-e (Phonons in crystal lattices)