Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide.
Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23-27 μW cm(-1) K(-2) at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereas comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. The corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Yeseul
Y
Lee
1] Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA [2].
Shih-Han
SH
Lo
1] Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA [2].
Changqiang
C
Chen
Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Hui
H
Sun
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Duck-Young
DY
Chung
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Thomas C
TC
Chasapis
Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Ctirad
C
Uher
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
Vinayak P
VP
Dravid
1] Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA [2] Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Mercouri G
MG
Kanatzidis