TY - JOUR
T1 - Lattice Dislocations Enhancing Thermoelectric PbTe in Addition to Band Convergence
AU - Chen, Zhiwei
AU - Jian, Zhengzhong
AU - Li, Wen
AU - Chang, Yunjie
AU - Ge, Binghui
AU - Hanus, Riley
AU - Yang, Jiong
AU - Chen, Yue
AU - Huang, Mingxin
AU - Snyder, Gerald Jeffrey
AU - Pei, Yanzhong
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant Nos. 51422208, 11474219, and 51401147), the National Recruitment Program of Global Youth Experts (1000 Plan), and the fundamental research funds for the central universities. Y.P. thanks Dr. Nicholas A. Heinz from NASA-JPL for his contribution on editing this paper. G.J.S. acknowledges Solid-State Solar-Thermal Energy Conversion Center (S3TEC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Basic Energy Sciences under Award No. DE-SC0001299 for financial support. The authors acknowledge the Shanghai Synchrotron Radiation Facility (SSRF) for providing the synchrotron XRD facility of beamline no. 14 B, and Zhiyuan Liang for the synchrotron experiment.
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/6/20
Y1 - 2017/6/20
N2 - Phonon scattering by nanostructures and point defects has become the primary strategy for minimizing the lattice thermal conductivity (κL) in thermoelectric materials. However, these scatterers are only effective at the extremes of the phonon spectrum. Recently, it has been demonstrated that dislocations are effective at scattering the remaining mid-frequency phonons as well. In this work, by varying the concentration of Na in Pb0.97Eu0.03Te, it has been determined that the dominant microstructural features are point defects, lattice dislocations, and nanostructure interfaces. This study reveals that dense lattice dislocations (≈4 × 1012 cm−2) are particularly effective at reducing κL. When the dislocation concentration is maximized, one of the lowest κL values reported for PbTe is achieved. Furthermore, due to the band convergence of the alloyed 3% mol. EuTe the electronic performance is enhanced, and a high thermoelectric figure of merit, zT, of ≈2.2 is achieved. This work not only demonstrates the effectiveness of dense lattice dislocations as a means of lowering κL, but also the importance of engineering both thermal and electronic transport simultaneously when designing high-performance thermoelectrics.
AB - Phonon scattering by nanostructures and point defects has become the primary strategy for minimizing the lattice thermal conductivity (κL) in thermoelectric materials. However, these scatterers are only effective at the extremes of the phonon spectrum. Recently, it has been demonstrated that dislocations are effective at scattering the remaining mid-frequency phonons as well. In this work, by varying the concentration of Na in Pb0.97Eu0.03Te, it has been determined that the dominant microstructural features are point defects, lattice dislocations, and nanostructure interfaces. This study reveals that dense lattice dislocations (≈4 × 1012 cm−2) are particularly effective at reducing κL. When the dislocation concentration is maximized, one of the lowest κL values reported for PbTe is achieved. Furthermore, due to the band convergence of the alloyed 3% mol. EuTe the electronic performance is enhanced, and a high thermoelectric figure of merit, zT, of ≈2.2 is achieved. This work not only demonstrates the effectiveness of dense lattice dislocations as a means of lowering κL, but also the importance of engineering both thermal and electronic transport simultaneously when designing high-performance thermoelectrics.
KW - band convergence
KW - lattice dislocations
KW - lattice thermal conductivity
KW - thermoelectrics
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U2 - 10.1002/adma.201606768
DO - 10.1002/adma.201606768
M3 - Article
C2 - 28397364
AN - SCOPUS:85017428167
VL - 29
JO - Advanced Materials
JF - Advanced Materials
SN - 0935-9648
IS - 23
M1 - 1606768
ER -