Discovery of multivalley Fermi surface responsible for the high thermoelectric performance in Yb14MnSb11 and Yb14MgSb11.
物理
声子
费米能级
电子
兴奋剂
塞贝克系数
作者
Christopher J. Perez,Maxwell Wood,Francesco Ricci,Guodong Yu,Trinh Vo,Sabah K. Bux,Geoffroy Hautier,Gian-Marco Rignanese,G. Jeffrey Snyder,Susan M. Kauzlarich
出处
期刊:Science Advances [American Association for the Advancement of Science (AAAS)] 日期:2021-01-20卷期号:7 (4)被引量:7
The Zintl phases, Yb14 MSb11 (M = Mn, Mg, Al, Zn), are now some of the highest thermoelectric efficiency p-type materials with stability above 873 K. Yb14MnSb11 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 Yb14Mg1-x Al x Sb11 (0 ≤ x ≤ 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 (N v = 8) band is responsible for the groundbreaking performance of Yb14 MSb11 This multiband understanding of the properties provides insight into other thermoelectric systems (La3-x Te4, SnTe, Ag9AlSe6, and Eu9CdSb9), and the model predicts that an increase in carrier concentration can lead to zT > 1.5 in Yb14 MSb11 systems.