TY - JOUR
T1 - Compromise and Synergy in High-Efficiency Thermoelectric Materials
AU - Zhu, Tiejun
AU - Liu, Yintu
AU - Fu, Chenguang
AU - Heremans, Joseph P.
AU - Snyder, Jeffrey G.
AU - Zhao, Xinbing
N1 - Funding Information:
The work was supported by the National Basic Research Program of China (2013CB632503), and the Nature Science Foundation of China (51271165, 11574267 and 61534001). J.P.H. acknowledges the support of the U.S. National Science Foundation under EFRI 2-DARE grant number 1433467, and editorial assistance from Ms. R. Ripley at Ohio State University.
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/4/11
Y1 - 2017/4/11
N2 - The past two decades have witnessed the rapid growth of thermoelectric (TE) research. Novel concepts and paradigms are described here that have emerged, targeting superior TE materials and higher TE performance. These superior aspects include band convergence, “phonon-glass electron-crystal”, multiscale phonon scattering, resonant states, anharmonicity, etc. Based on these concepts, some new TE materials with distinct features have been identified, including solids with high band degeneracy, with cages in which atoms rattle, with nanostructures at various length scales, etc. In addition, the performance of classical materials has been improved remarkably. However, the figure of merit zT of most TE materials is still lower than 2.0, generally around 1.0, due to interrelated TE properties. In order to realize an “overall zT > 2.0,” it is imperative that the interrelated properties are decoupled more thoroughly, or new degrees of freedom are added to the overall optimization problem. The electrical and thermal transport must be synergistically optimized. Here, a detailed discussion about the commonly adopted strategies to optimize individual TE properties is presented. Then, four main compromises between the TE properties are elaborated from the point of view of the underlying mechanisms and decoupling strategies. Finally, some representative systems of synergistic optimization are also presented, which can serve as references for other TE materials. In conclusion, some of the newest ideas for the future are discussed.
AB - The past two decades have witnessed the rapid growth of thermoelectric (TE) research. Novel concepts and paradigms are described here that have emerged, targeting superior TE materials and higher TE performance. These superior aspects include band convergence, “phonon-glass electron-crystal”, multiscale phonon scattering, resonant states, anharmonicity, etc. Based on these concepts, some new TE materials with distinct features have been identified, including solids with high band degeneracy, with cages in which atoms rattle, with nanostructures at various length scales, etc. In addition, the performance of classical materials has been improved remarkably. However, the figure of merit zT of most TE materials is still lower than 2.0, generally around 1.0, due to interrelated TE properties. In order to realize an “overall zT > 2.0,” it is imperative that the interrelated properties are decoupled more thoroughly, or new degrees of freedom are added to the overall optimization problem. The electrical and thermal transport must be synergistically optimized. Here, a detailed discussion about the commonly adopted strategies to optimize individual TE properties is presented. Then, four main compromises between the TE properties are elaborated from the point of view of the underlying mechanisms and decoupling strategies. Finally, some representative systems of synergistic optimization are also presented, which can serve as references for other TE materials. In conclusion, some of the newest ideas for the future are discussed.
KW - band engineering
KW - electrical properties
KW - nanostructuring
KW - thermal conductivity
KW - thermoelectrics
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U2 - 10.1002/adma.201605884
DO - 10.1002/adma.201605884
M3 - Review article
C2 - 28262991
AN - SCOPUS:85014644101
VL - 29
JO - Advanced Materials
JF - Advanced Materials
SN - 0935-9648
IS - 14
M1 - 1605884
ER -