All-scale hierarchical thermoelectrics: MgTe in PbTe facilitates valence band convergence and suppresses bipolar thermal transport for high performance

被引：674

作者：

Zhao, L. D. ^{[1
]}

Wu, H. J. ^{[2
]}

Hao, S. Q. ^{[3
]}

Wu, C. I. ^{[4
]}

Zhou, X. Y. ^{[5
]}

Biswas, K. ^{[1
]}

He, J. Q. ^{[2
]}

Hogan, T. P. ^{[4
]}

Uher, C. ^{[5
]}

Wolverton, C. ^{[3
]}

Dravid, V. P. ^{[3
]}

Kanatzidis, M. G. ^{[1
]}

机构：

[1] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA

[2] South Univ Sci & Technol China, Dept Phys, Shenzhen 518055, Peoples R China

[3] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[4] Michigan State Univ, Dept Elect & Comp Engn, E Lansing, MI 48824 USA

[5] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA

来源：

ENERGY & ENVIRONMENTAL SCIENCE | 2013年 / 6卷 / 11期

关键词：

P-TYPE PBS; BULK THERMOELECTRICS; CONDUCTIVITY; FIGURE; AGPBMSBTE2+M;

D O I：

10.1039/c3ee42187b

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We report a high ZT of similar to 2.0 at 823 K for 2% Na-doped PbTe with 6% MgTe with excellent thermal stability. We attribute the high thermoelectric performance to a synergistic combination of enhanced power factor, reduction of the lattice thermal conductivity and simultaneous suppression of bipolar thermal conductivity. MgTe inclusion in PbTe owns triple functions: the Mg alloying within the solubility limit in PbTe modifies the valence band structure by pushing the two valence bands (L and Sigma bands) closer in energy, thereby facilitating charge carrier injection. When the solubility limit of Mg is exceeded, ubiquitous endotaxial nanostructures form, which when coupled with mesoscale microstructuring results in a very low (lattice) thermal conductivity through all-scaled length phonon scattering. Meanwhile, most significantly, the Mg alloying enlarges the energy gap of conduction band (C band) and light valence band (L band), thereby suppresses the bipolar thermal conductivity through an increase in band gap.

引用

页码：3346 / 3355

页数：10

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