Enhancing the Thermoelectric Power Factor with Highly Mismatched Isoelectronic Doping
We investigate the effect of O impurities on the thermoelectric properties of ZnSe from a combination of first-principles and analytic calculations. It is demonstrated that dilute amounts of O impurities introduce peaks in the density of states (DOS) above the conduction band minimum, and that the...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2010
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| Online Access: | http://hdl.handle.net/1721.1/56609 https://orcid.org/0000-0003-1281-2359 |
| Summary: | We investigate the effect of O impurities on the thermoelectric properties of ZnSe from a combination
of first-principles and analytic calculations. It is demonstrated that dilute amounts of O impurities
introduce peaks in the density of states (DOS) above the conduction band minimum, and that the charge
density near the DOS peaks is substantially attracted toward O atoms due to their high electronegativity.
The impurity-induced peaks in the DOS result in a sharp increase of the room-temperature Seebeck
coefficient and power factor from those of O-free ZnSe by a factor of 30 and 180, respectively.
Furthermore, this effect is found to be absent when the impurity electronegativity well matches the
host that it substitutes. The results suggest that highly electronegativity-mismatched alloys can be
designed for high performance thermoelectric applications. |
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