APPLICATIONS OF TECHNOLOGY:
Thermoelectric materials for
- Waste heat recovery from power plants, automobiles, and other heat sources
- Solid state cooling
- Interfacial thermal management
- Simultaneous improvement in
- Electrical conductivity (up to 200%)
- Thermopower (up to 70%)
- Enhanced ZT (approximately 1.4) at room temperature
- No need for further complicated, expensive material processing
Researchers at Berkeley Lab have developed a technology for enhanced thermoelectric performance by tailoring key properties of semiconductor materials with high-energy ion irradiation. In the past, improvements in electrical conductivity, thermopower, and thermal resistivity could not be achieved simultaneously. In fact, improvements to two out of the three parameters came at the cost of diminishing the third. The Berkeley Lab technology, however, yields a simultaneous increase in electrical conductivity (up to 200%) and thermopower (up to 70%) to reach a thermoelectric figure of merit (ZT) of approximately 1.4 at room temperature.
The ion beam processing is performed post-growth and is controlled by alpha particle irradiation. The technology generates native defects (NDs), such as vacancies and interstitial defects, in the thermoelectric material, which break the usual antagonistic coupling among electrical conductivity, thermopower, and thermal resistivity. NDs serve as electron donors, energy-dependent scattering centers, and phonon blockers, and optimization of NDs leads to an enhanced ZT without further complex and costly processing.
DEVELOPMENT STAGE: Proven principle.
STATUS: Patent pending. Available for licensing or collaborative research.
FOR MORE INFORMATION: Suh, J., Yu, K. M., Fu, D., Liu, X., Yang, F., Fan, J., Smith, D. J., Zhang, Y.-H., Furdyna, J. K., Dames, C., Walukiewicz, W., Wu, J. “Simultaneous enhancement of electrical conductivity and thermopower of Bi2Te3 by multifunctionality of native defects,” Advanced Materials, 27, 3681−3686 (2015).
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
Optimized Nanostructures for Flexible, Scalable Thermoelectric Materials, 2015-085, 2015-086, 2015-091