Abstract
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−1K−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.
Original language | English (US) |
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Pages (from-to) | 11431-11436 |
Number of pages | 6 |
Journal | Angewandte Chemie - International Edition |
Volume | 55 |
Issue number | 38 |
DOIs | |
State | Published - Sep 12 2016 |
Funding
This work was supported by the National Natural Science Foundation of China under Projects (21571020, 20973175, 21233009, 21301175, 21225104, and 91422303) and the NSF of Fujian Province (No. 2015J01071). At Northwestern this work (sample preparation, thermoelectric measurements, DFT calculations) was supported by the Department of Energy, Office of Science Basic Energy Sciences grant DE-SC0014520.
Keywords
- CsAgTe
- concerted rattling
- thermoelectric materials
- tunnel structure
- ultralow thermal conductivity
ASJC Scopus subject areas
- Catalysis
- General Chemistry