Issue 6, 2018

Enhanced thermoelectric performance through synergy of resonance levels and valence band convergence via Q/In (Q = Mg, Ag, Bi) co-doping

Abstract

The temperature-dependent evolution of heavy-hole valence band contribution to the Seebeck coefficients of SnTe-based thermoelectric materials is revealed in situ by neutron and synchrotron powder diffraction. The additional carriers with high effective mass are created in a heavy-hole valence band above 493 K, which contribute to the electrical transport, and lead to a significant enhancement of the Seebeck coefficient at high temperature. In addition, remarkably improved electrical transport properties are achieved through the synergetic effects of the resonance levels, the valence band convergence, and the carrier concentration optimization by co-doping with Mg & In, Ag & In and Bi & In. Significant reduction in the lattice thermal conductivity is obtained by multiscale phonon scattering over a wide spectrum via atomic point defects, nanoscale elongated screw dislocations with random directions, and the microscale grain boundaries caused by sintering. As a result, a high figure of merit, ZT, of ∼1 at 873 K is obtained for the Mg0.015In0.015Sn0.97Te sample.

Graphical abstract: Enhanced thermoelectric performance through synergy of resonance levels and valence band convergence via Q/In (Q = Mg, Ag, Bi) co-doping

Supplementary files

Article information

Article type
Paper
Submitted
17 Okt. 2017
Accepted
22 Nov. 2017
First published
22 Nov. 2017

J. Mater. Chem. A, 2018,6, 2507-2516

Enhanced thermoelectric performance through synergy of resonance levels and valence band convergence via Q/In (Q = Mg, Ag, Bi) co-doping

L. J. Zhang, P. Qin, C. Han, J. L. Wang, Z. H. Ge, Q. Sun, Z. X. Cheng, Z. Li and S. X. Dou, J. Mater. Chem. A, 2018, 6, 2507 DOI: 10.1039/C7TA09117F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements