Guo Zhe, Wu Gang, Tan Xiaojian, Wang Ruoyu, Yan Zipeng, Zhang Qiang, Song Kun, Sun Peng, Hu Haoyang, Cui Chen, Liu Guo-Qiang, Jiang Jun
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2022 Jun 29;14(25):29032-29038. doi: 10.1021/acsami.2c07548. Epub 2022 Jun 15.
In the mid-temperature region, SnTe is a promising substitute for PbTe, whereas the thermoelectric (TE) property of pristine SnTe is severely limited by the good thermal conductivity and inferior Seebeck coefficient. In this research, we synergistically manipulate the interdependent TE parameters of SnTe-AgBiTe alloys by Mn doping to increase the value. The AgBiTe alloying is found to greatly reduce the electrical conductivity and electronic contribution for thermal transport by reducing the carrier mobility, while Mn doping obviously improves the Seebeck coefficient by effectively decreasing the valence band offset. The lowest κ of Mn-doped SnTe-AgBiTe alloys is 0.49 W m K at 823 K since the various defects strengthen the phonon scattering. Collectively, these manipulations yield a peak value of 1.40 at 823 K and an average value of 0.73 (300-823 K) in the Mn-doped SnTe-AgBiTe alloys. This research suggests that Mn doping is a valid scheme to constantly improve the thermoelectric property of SnTe-AgBiTe alloys in a wide temperature range.
在中温区域，SnTe是一种很有前景的替代PbTe的材料，然而，原始SnTe的热电（TE）性能受到良好的热导率和较差的塞贝克系数的严重限制。在本研究中，我们通过Mn掺杂协同调控SnTe-AgBiTe合金相互关联的TE参数，以提高ZT值。研究发现，AgBiTe合金化通过降低载流子迁移率极大地降低了电导率和电子对热输运的贡献，而Mn掺杂通过有效降低价带偏移明显提高了塞贝克系数。由于各种缺陷增强了声子散射，Mn掺杂的SnTe-AgBiTe合金在823 K时的最低热导率κ为0.49 W m-1 K-1。总体而言，这些调控使得Mn掺杂的SnTe-AgBiTe合金在823 K时的峰值ZT值达到1.40，在300 - 823 K范围内的平均ZT值为0.73。本研究表明，Mn掺杂是在宽温度范围内持续改善SnTe-AgBiTe合金热电性能的有效方案。
