Back to Search Start Over

High Thermoelectric Performance in Supersaturated Solid Solutions and Nanostructured n‐Type PbTe–GeTe.

Authors :
Luo, Zhong‐Zhen
Zhang, Xiaomi
Hua, Xia
Tan, Gangjian
Bailey, Trevor P.
Xu, Jianwei
Uher, Ctirad
Wolverton, Chris
Dravid, Vinayak P.
Yan, Qingyu
Kanatzidis, Mercouri G.
Source :
Advanced Functional Materials; 8/1/2018, Vol. 28 Issue 31, p1-1, 10p
Publication Year :
2018

Abstract

Abstract: Sb‐doped and GeTe‐alloyed n‐type thermoelectric materials that show an excellent figure of merit ZT in the intermediate temperature range (400–800 K) are reported. The synergistic effect of favorable changes to the band structure resulting in high Seebeck coefficient and enhanced phonon scattering by point defects and nanoscale precipitates resulting in reduction of thermal conductivity are demonstrated. The samples can be tuned as single‐phase solid solution (SS) or two‐phase system with nanoscale precipitates (Nano) based on the annealing processes. The GeTe alloying results in band structure modification by widening the bandgap and increasing the density‐of‐states effective mass of PbTe, resulting in significantly enhanced Seebeck coefficients. The nanoscale precipitates can improve the power factor in the low temperature range and further reduce the lattice thermal conductivity (κ<subscript>lat</subscript>). Specifically, the Seebeck coefficient of Pb<subscript>0.988</subscript>Sb<subscript>0.012</subscript>Te–13%GeTe–Nano approaches −280 µV K<superscript>−1</superscript> at 673 K with a low κ<subscript>lat</subscript> of 0.56 W m<superscript>−1</superscript> K<superscript>−1</superscript> at 573 K. Consequently, a peak ZT value of 1.38 is achieved at 623 K. Moreover, a high average ZT<subscript>avg</subscript> value of ≈1.04 is obtained in the temperature range from 300 to 773 K for n‐type Pb<subscript>0.988</subscript>Sb<subscript>0.012</subscript>Te–13%GeTe–Nano. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1616301X
Volume :
28
Issue :
31
Database :
Complementary Index
Journal :
Advanced Functional Materials
Publication Type :
Academic Journal
Accession number :
131012310
Full Text :
https://doi.org/10.1002/adfm.201801617