金属学报英文版 ›› 2025, Vol. 38 ›› Issue (5): 859-868.DOI: 10.1007/s40195-024-01790-1

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  • 收稿日期:2024-07-17 修回日期:2024-09-07 接受日期:2024-09-10 出版日期:2025-05-10 发布日期:2024-11-16

Efficient Reduction of Carrier Concentration in SnTe: The Case of Gd Doping

Siqi Lin1, Shiyun Wang1, Yanjiao Li1, Zhenyu Lai1, Xiaotang Yang1, Xinyu Lu1, Min Jin1()   

  1. 1College of Materials, Shanghai Dianji University, Shanghai 201306, China
  • Received:2024-07-17 Revised:2024-09-07 Accepted:2024-09-10 Online:2025-05-10 Published:2024-11-16
  • Contact: Min Jin,jmaish@aliyun.com

Abstract:

Lead-free SnTe with naturally non-stoichiometric vacancies has a limited thermoelectric performance due to a deviated carrier concentration from the optimum. In this paper, we experimentally demonstrated that Gd with + 3 valence state as a novel n-type dopant is an effective solution for reducing carrier concentration in SnTe. A lowest value of 7.6 × 1018 cm−3 has been achieved. Yet with the involvement of Gd doping, the slightly modified band structure requires a further Sn-deficiency compensation to enhance the overall figure of merit zT. As a consequence, in the specific sample Sn0.91Gd0.07Te, we successfully achieved a low lattice thermal conductivity of 0.8 W/(m K) due to the high doping level and an improved zT approaching 0.8 at 850 K.

Key words: SnTe, Band engineering, Solubility, Thermoelectric performance