Low effective mass leading to high thermoelectric performance
Abstract
High Seebeck coefficient by creating large density-of-states effective mass through either electronic structure modification or manipulating nanostructures is commonly considered as a route to advanced thermoelectrics. However, large density-of-state due to flat bands leads to large transport effective mass, which results in a simultaneous decrease of mobility. In fact, the net effect of such a high effective mass is a lower thermoelectric figure of merit, zT, when the carriers are predominantly scattered by phonons according to the deformation potential theory of Bardeen–Shockley. We demonstrate that the beneficial effect of light effective mass contributes to high zT in n-type thermoelectric PbTe, where doping and temperature can be used to tune the effective mass. This clear demonstration of the deformation potential theory to thermoelectrics shows that the guiding principle for band structure engineering should be low effective mass along the transport direction.
Additional Information
© 2012 Royal Society of Chemistry. Received 3rd March 2012, Accepted 24th April 2012. This work is supported by NASA-JPL and DARPA Nano Materials Program.Attached Files
Published - Pei2012p18818Energ_Environ_Sci.pdf
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Additional details
- Eprint ID
- 32418
- Resolver ID
- CaltechAUTHORS:20120713-101613448
- NASA
- JPL
- DARPA Nano Materials Program
- Created
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2012-07-13Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field