Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides
Abstract
While thermoelectric materials can be used for solid state cooling, waste heat recovery, and solar electricity generation, low values of the thermoelectric figure of merit, zT, have led to an efficiency too low for widespread use. Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu 2Se over a broad (360–410 K) temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K), and a similar but larger increase over a wider temperature range in the zT of Cu 1.97 Ag .03Se (almost 1.0 at 400 K). The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics.
Additional Information
© 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. Received 16 August 2013 Accepted 17 October 2013 Published online 14 November 2013. The authors would like to acknowledge Huili Liu, Dr. Xun Shi and Dr. Lidong Chen of SIC-CAS for discussions and assistance with heat capacity measurements; Alex Z. Williams and the NASA-JPL for aid in measuring the Hall coefficient; and Resnick Institute and Air Force Office of Science Research for support. Use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.Attached Files
Published - APL_Materials.pdf
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Additional details
- Eprint ID
- 42568
- Resolver ID
- CaltechAUTHORS:20131119-110722220
- Department of Energy (DOE)
- DE-AC02-06CH11357
- Created
-
2013-11-20Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute