Modified polyol synthesis of bulk-scale nanostructured bismuth antimony telluride

Authors

Mary Elizabeth Anderson, Furman UniversityFollow
S. S.N. Bharadwaya
R. E. Schaak

ACS Citation

Anderson, M.E.; Bharadwaya, S.S.N.; Schaak, R.E. Modified Polyol Synthesis of Bulk-Scale Nanostructured Bismuth Antimony Telluride. J. Mater. Chem.2010,20, 8362-8367.

Version of Record

10.1039/C0JM01424A

Abstract

Bismuth antimony telluride, Bi_0.5Sb_1.5Te₃, is a prototype thermoelectric alloy for which nanostructuring has been shown to improve the thermoelectric figure of merit. Most bulk-scale nanostructured thermoelectric materials are synthesized using either traditional solid-state routes or “top-down” physical methods such as ball milling, sputtering, etc. “Bottom-up” chemical methods represent an important alternative route to nanostructured thermoelectrics, but often produce small sample sizes that make transport measurements difficult. Here, nanostructured Bi_0.5Sb_1.5Te₃ has been synthesized in half-gram quantities using a simple and scalable modified polyol process. Stoichiometric amounts of appropriate metal salts were combined in tetraethylene glycol with and without poly(vinylpyrrolidone) (PVP), reduced with sodium borohydride, and heated in solution and in powder form to obtain samples of crystalline Bi_0.5Sb_1.5Te₃. The structure, composition, and morphology of the products were characterized using powder XRD, TEM, SEM, and EDS mapping data. The Seebeck coefficient, measured from 300-500 K for 1 cm sintered pellets of Bi_0.5Sb_1.5Te₃, increased with temperature and was found to be +256 µV K⁻¹ at 500 K. Bulk-scale nanostructured powders of other thermoelectrics could also be synthesized, including Bi₂Te₃, PbTe, Sb₂Te₃, AgSbTe_{2, and Pb1−xSnxTe.}

Source Name

Journal of Materials Chemistry

Publication Date

8-26-2010

Volume

20

Page(s)

8362-8367

Document Type

Citation

Citation Type

Article