Identifying polymorphic lattice positioning of copper and the effects on the thermoelectric performance of δ-LAST

Li，Yaqin1; Ma，Baopeng1; Zhu，Lujun2; Liu，Shixuan3; Zhang，Fudong1; Li，Xiaojun1; Liang，Pengfei2; Chao，Xiaolian1; Yang，Zupei1; He，Jiaqing3; Wu，Di1

2022-10-01

10.1016/j.mtphys.2022.100833

Materials Today Physics   Impact Factor & Quartile

2542-5293

2542-5293

N-type AgPbSbTe (abbreviated as LAST-m) has attracted much attention as an important branch of PbTe-based thermoelectric materials, mainly due to its complex microstructure and ultralow thermal conductivity. However, LAST-m met much difficulty in repeatability and reproducibility of thermoelectric performance largely due to the meta-stable feature of the component AgSbTe. In this work, we replaced stoichiometric AgSbTe with non-stoichiometric AgSbTe, and alloyed it with PbTe to get thermodynamically stable and single-phase δ-LAST solid solutions. Further addition of extra Cu with excess dose results in the polymorphic lattice positioning of Cu atoms in the matrix of δ-LAST as revealed by C-corrected scanning transmission electron microscope (STEM), i.e., single Cu interstitial, Cu interstitial monolayer, Cu interstitial bilayer, Cu interstitial super-lattice, Cu interstitial intermediate compound and CuTe. It was argued that the polymorphic positioning of Cu atoms not only dynamically optimize the electron concentration at climbing temperatures but also effectively scatter heat-carrying phonons in a panoscopic approach, leading to an outstanding thermoelectric performance competitive with state-of-art LAST-m and other n-type PbTe-based thermoelectrics.

Cu interstitial Dislocation array Semi-coherent phase boundary δ-LAST

SCI

English

Others

Natural Science Basic Research Program of Shaanxi Province[2021JM-201];Natural Science Basic Research Program of Shaanxi Province[2021ZDLSF06-03];National Natural Science Foundation of China[51872177];Fundamental Research Funds for the Central Universities[GK202002014];

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied

WOS:000862692600003

ELSEVIER

2-s2.0-85138090143

Scopus

1.Key Laboratory for Macromolecular Science of Shaanxi Province and Shaanxi Key Laboratory for Advanced Energy Devices,School of Materials and Engineering,Shaanxi Normal University,Xi'an,710062,China
2.School of Physics and Information Technology,Shaanxi Normal University,Xi'an,710119,China
3.Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China

Li，Yaqin,Ma，Baopeng,Zhu，Lujun,et al. Identifying polymorphic lattice positioning of copper and the effects on the thermoelectric performance of δ-LAST[J]. Materials Today Physics,2022,27.

Li，Yaqin.,Ma，Baopeng.,Zhu，Lujun.,Liu，Shixuan.,Zhang，Fudong.,...&Wu，Di.(2022).Identifying polymorphic lattice positioning of copper and the effects on the thermoelectric performance of δ-LAST.Materials Today Physics,27.

Li，Yaqin,et al."Identifying polymorphic lattice positioning of copper and the effects on the thermoelectric performance of δ-LAST".Materials Today Physics 27(2022).