Improving Thermoelectric Performance of alpha-MgAgSb by Theoretical Band Engineering Design
Improving Thermoelectric Performance of alpha-MgAgSb by Theoretical Band Engineering Design
复制标题
通过理论能带工程设计提高α-MgAgSb的热电性能
DOI：
10.1002/aenm.201700076
复制
发表时间：
2017
影响因子：
27.8
通讯作者：
Jiang Jun
中科院分区：
文献类型：
--
作者：
Tan Xiaojian;Wang Ling;Shao Hezhu;Yue Song;Xu Jingtao;Liu Guoqiang;Jiang Haochuan;Jiang Jun
α‐MgAgSb is recently discovered to be a new class of thermoelectric material near room temperature. A competitiveZTof 1.4 at 525 K is achieved in Ni‐doped α‐MgAgSb, and the measured efficiency of energy conversion reaches a record value of 8.5%, which is even higher than that of the commercially applied material bismuth telluride. On the other hand, the band structure of α‐MgAgSb is believed to be unprofitable to the power factor, owing to the less degenerate valence valleys. Here, this paper reports a systematic theoretical study on the thermoelectric properties by using the electron/phonon structure and transport calculations. Based on the careful analysis of Fermi surface, a principled scheme is presented to design band engineering in α‐MgAgSb. Following the given rules, several effective dopants are predicted. As two examples, Zn‐ and Pd‐doped α‐MgAgSb are numerically confirmed to exhibit an extraordinaryZTvalue of 2.0 at 575 K and a high conversion efficiency of 12.6%, owing to the effects of band convergence. This work develops an applicable scheme for the purposive design of band engineering, and the idea can be simply applied to more thermoelectric materials.
