Seebeck and figure of merit enhancement in nanostructured antimony telluride by antisite defect suppression through sulfur doping.
Antimony telluride has a low thermoelectric figure of merit (ZT < ∼0.3) because of a low Seebeck coefficient α arising from high degenerate hole concentrations generated by antimony antisite defects. Here, we mitigate this key problem by suppressing antisite defect formation using subatomic percent sulfur doping. The resultant 10-25% higher α in bulk nanocrystalline antimony telluride leads to ZT ∼ 0.95 at 423 K, which is superior to the best non-nanostructured antimony telluride alloys. Density functional theory calculations indicate that sulfur increases the antisite formation activation energy and presage further improvements leading to ZT ∼ 2 through optimized doping. Our findings are promising for designing novel thermoelectric materials for refrigeration, waste heat recovery, and solar thermal applications.
Materials Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Rutvik J
RJ
Mehta
Yanliang
Y
Zhang
Hong
H
Zhu
David S
DS
Parker
Matthew
M
Belley
David J
DJ
Singh
Ramamurthy
R
Ramprasad
Theodorian
T
Borca-Tasciuc
Ganpati
G
Ramanath
D000965:Antimony / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D004735:Energy Transfer; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013455:Sulfur / Q000737:chemistry*; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry*; D013696:Temperature; D013814:Thermal Conductivity
D046911:Macromolecular Substances; D013455:Sulfur; D000965:Antimony; C026660:tellurous acid; D013691:Tellurium