Perez Christopher J, Wood Maxwell, Ricci Francesco, Yu Guodong, Vo Trinh, Bux Sabah K, Hautier Geoffroy, Rignanese Gian-Marco, Snyder G Jeffrey, Kauzlarich Susan M
Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616, USA.
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
Sci Adv. 2021 Jan 20;7(4). doi: 10.1126/sciadv.abe9439. Print 2021 Jan.
The Zintl phases, Yb Sb ( = Mn, Mg, Al, Zn), are now some of the highest thermoelectric efficiency p-type materials with stability above 873 K. YbMnSb gained prominence as the first p-type thermoelectric material to double the efficiency of SiGe alloy, the heritage material in radioisotope thermoelectric generators used to power NASA's deep space exploration. This study investigates the solid solution of YbMg Al Sb (0 ≤ ≤ 1), which enables a full mapping of the metal-to-semiconductor transition. Using a combined theoretical and experimental approach, we show that a second, high valley degeneracy ( = 8) band is responsible for the groundbreaking performance of Yb Sb This multiband understanding of the properties provides insight into other thermoelectric systems (La Te, SnTe, AgAlSe, and EuCdSb), and the model predicts that an increase in carrier concentration can lead to > 1.5 in Yb Sb systems.
津特耳相YbSb（其中Sb = Mn、Mg、Al、Zn）如今是一些热效率最高的p型材料，其稳定性高于873K。YbMnSb作为第一种使硅锗合金（用于为美国国家航空航天局深空探索提供动力的放射性同位素热电发电机中的传统材料）效率翻倍的p型热电材料而声名远扬。本研究考察了YbMgₓAl₁₋ₓSb（0 ≤ x ≤ 1）的固溶体，这使得能够全面描绘金属到半导体的转变。通过理论与实验相结合的方法，我们表明第二个具有高谷简并度（g = 8）的能带是YbₓSb突破性性能的原因。这种对性质的多能带理解为其他热电系统（LaTe、SnTe、AgAlSe和EuCdSb）提供了见解，并且该模型预测，在YbₓSb系统中载流子浓度的增加可导致zT > 1.5。
