Influence of High-Pressure Induced Lattice Dislocations and Distortions on Thermoelectric Performance of Pristine SnTe  

作　　者：郑博文 陈涛 孙海瑞 杨曼曼 杨兵超 陈欣 张永胜 刘晓兵 Bowen Zheng;Tao Chen;Hairui Sun;Manman Yang;Bingchao Yang;Xin Chen;Yongsheng Zhang;Xiaobing Liu(Laboratory of High-Pressure Physics and Materials Science,School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China;Advanced Research Institute of Multidisciplinary Sciences,Qufu Normal University,Qufu 273165,China;Key Lab of Photovoltaic and Energy Conservation Materials Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;School of Electronic Engineering Huainan Normal University,Huainan 232038,China)

机构地区：[1]Laboratory of High-Pressure Physics and Materials Science,School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China [2]Advanced Research Institute of Multidisciplinary Sciences,Qufu Normal University,Qufu 273165,China [3]Key Lab of Photovoltaic and Energy Conservation Materials Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China [4]University of Science and Technology of China,Hefei 230026,China [5]School of Electronic Engineering Huainan Normal University,Huainan 232038,China

出　　处：《Chinese Physics Letters》2024年第5期61-68,共8页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 12374012, 11974208, 52172212, and 52002217);Shandong Provincial Natural Science Foundation (Grant Nos. ZR2023JQ001, ZR2020YQ05, and 2019KJJ020);financial support from the Program of Distinguished Expert of Taishan Scholar (Grant No. tstp20221124)。

摘　　要：As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpositions and high thermal conductivity. Using high-pressure and high-temperature technology, we synthesized the pristine SnTe samples at different pressures and systemically investigated their thermoelectric properties.High pressure induces rich microstructures, including the high-density dislocations and lattice distortions, which serve as the strong phonon scattering centers, thereby reducing the lattice thermal conductivity. For the electrical properties, pressure reduces the harmful high carrier concentration, due to the depression of Sn vacancies.Moreover, pressure induces the valence band convergence, reducing the energy separation between the L and Σpositions. The band convergence and suppressed carrier concentration increase the Seebeck coefficient. Thus, the power factors of pressure-sintered compounds do not deteriorate significantly under the condition of decreasing electrical conductivity. Ultimately, for a pristine SnTe compound synthesized at 5 GPa, a higher ZT value of 0.51 is achieved at 750 K, representing a 140% improvement compared to the value of 0.21 obtained using SPS. Therefore, the high-pressure and high-temperature technology is demonstrated as an effectively approach to optimize thermoelectric performance.

关 键 词：COEFFICIENT PROPERTIES POSITIONS 

分 类 号：O469[理学—凝聚态物理]