Concerted Rattling in CsAg₅Te₃ Leading to Ultralow Thermal Conductivity and High Thermoelectric Performance

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• 作者：Dr. Hua Lin ; Dr. Gangjian Tan ; Dr. Jin-Ni Shen ; Dr. Shiqiang Hao ; Prof. Li-Ming Wu ; Dr. Nicholas Calta ; Dr. Christos Malliakas ; Si Wang ; Prof. Ctirad Uher ; Prof. Christopher Wolverton and Prof. Mercouri G. Kanatzidis
• 刊名：Angewandte Chemie
• 出版年：2016
• 出版时间：September 12, 2016
• 年：2016
• 卷：128
• 期：38
• 页码：11603-11608
• 全文大小：3009K
• ISSN：1521-3757

文摘

Thermoelectric (TE) materials convert heat energy directly into electricity, and introducing new materials with high conversion efficiency is a great challenge because of the rare combination of interdependent electrical and thermal transport properties required to be present in a single material. The TE efficiency is defined by the figure of merit ZT=(S²σ) T/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the total thermal conductivity, and T is the absolute temperature. A new p-type thermoelectric material, CsAg₅Te₃, is presented that exhibits ultralow lattice thermal conductivity (ca. 0.18 Wm⁻¹ K⁻¹) and a high figure of merit of about 1.5 at 727 K. The lattice thermal conductivity is the lowest among state-of-the-art thermoelectrics; it is attributed to a previously unrecognized phonon scattering mechanism that involves the concerted rattling of a group of Ag ions that strongly raises the Grüneisen parameters of the material.