Justl Andrew P, Ricci Francesco, Pike Andrew, Cerretti Giacomo, Bux Sabah K, Hautier Geoffroy, Kauzlarich Susan M
Department of Chemistry, University of California, One Shields Ave, Davis, CA 95616, USA.
Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain (UCLouvain), Chemin étoiles 8, bte L7.03.01, Louvain-la-Neuve 1348, Belgium.
Sci Adv. 2022 Sep 9;8(36):eabq3780. doi: 10.1126/sciadv.abq3780. Epub 2022 Sep 7.
YbMnSb and YbMgSb are among the best p-type high-temperature (>1200 K) thermoelectric materials, yet other compounds of this CaAlSb structure type have not matched their stability and efficiency. First-principles computations show that the features in the electronic structures that have been identified to lead to high thermoelectric performances are present in YbZnSb, which has been presumed to be a poor thermoelectric material. We show that the previously reported low power factor of YbZnSb is not intrinsic and is due to the presence of a YbZnSb impurity uniquely present in the Zn system. Phase-pure YbZnSb synthesized through a route avoiding the impurity formation reveals its exceptional high-temperature thermoelectric properties, reaching a peak of 1.2 at 1175 K. Beyond YbZnSb, the favorable band structure features for thermoelectric performance are universal among the CaAlSb structure type, opening the possibility for high-performance thermoelectric materials.
YbMnSb和YbMgSb是最好的p型高温（>1200 K）热电材料之一，但这种CaAlSb结构类型的其他化合物在稳定性和效率方面并未与之匹配。第一性原理计算表明，已被确定为导致高热电性能的电子结构特征存在于YbZnSb中，而YbZnSb一直被认为是一种较差的热电材料。我们表明，先前报道的YbZnSb的低功率因数并非其固有特性，而是由于锌体系中独特存在的YbZnSb杂质所致。通过避免杂质形成的路线合成的纯相YbZnSb展现出其优异的高温热电性能，在1175 K时达到峰值1.2。除YbZnSb外，有利于热电性能的能带结构特征在CaAlSb结构类型中普遍存在，为高性能热电材料开辟了可能性。
