“Paleoartists” attempt to hone their craft and captivate the public even as they grapple with emerging data that alter how we see dinosaurs.
Image credit: Mark Witton.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Contributed by Ching-Wu Chu, October 24, 2016 (sent for review September 7, 2016; reviewed by Jing-Feng Li and Silke Paschen)
Significance
Thermoelectric technology can boost energy consumption efficiency by converting some of the waste heat into useful electricity. Heat-to-power conversion efficiency optimization is mainly achieved by decreasing the thermal conductivity in many materials. In comparison, there has been much less success in increasing the power factor. We report successful power factor enhancement by improving the carrier mobility. Our successful approach could suggest methods to improve the power factor in other materials. Using our approach, the highest power factor reaches ∼106 μW⋅cm−1⋅K−2 at room temperature. Such a high power factor further yields a record output power density in a single-leg device tested between 293 K and 868 K, thus demonstrating the importance of high power factor for power generation applications.
Abstract
Improvements in thermoelectric material performance over the past two decades have largely been based on decreasing the phonon thermal conductivity. Enhancing the power factor has been less successful in comparison. In this work, a peak power factor of ∼106 μW⋅cm−1⋅K−2 is achieved by increasing the hot pressing temperature up to 1,373 K in the p-type half-Heusler Nb0.95Ti0.05FeSb. The high power factor subsequently yields a record output power density of ∼22 W⋅cm−2 based on a single-leg device operating at between 293 K and 868 K. Such a high-output power density can be beneficial for large-scale power generation applications.
Footnotes
- ↵1To whom correspondence may be addressed. Email: cwchu{at}uh.edu, gchen2{at}mit.edu, or zren{at}uh.edu.
Author contributions: R.H. and Z.R. designed research; R.H. performed research; D.K., L.Z., Y. Lan, C.L., J.S., H.S.K., Y. Liu, and D.B. contributed new reagents/analytic tools; R.H., J.M., Q.J., G.C., and Z.R. analyzed data; and R.H., D.K., L.Z., D.B., C.-W.C., G.C., and Z.R. wrote the paper.
Reviewers: J.-F.L., Tsinghua University; and S.P., Vienna University of Technology.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1617663113/-/DCSupplemental.
High power factor and power density in NbFeSb
Sign up for Article Alerts
Article Classifications
- Physical Sciences
- Applied Physical Sciences
Jump to section
- Article
- Abstract
- Materials and Methods
- Results and Discussion
- Conclusions
- Sample Characterization
- Thermal Diffusivity and Specific Heat
- Band Structure and Bipolar Thermal Conductivity
- Grain Size Distribution
- Measuring Phonon MFP Distribution in Nb0.95Ti0.05FeSb
- Klemens Model
- Calculation of Efficiency and Power Density
- Measurement of Efficiency and Power Density
- Acknowledgments
- Footnotes
- References
- Figures & SI
- Info & Metrics
You May Also be Interested in
Coral reef bleaching frequently makes headlines, but researchers are still trying to sort out the cellular mechanisms at work.
Image credit: The Ocean Agency/XL Catlin Seaview Survey.
Greenhouse gas emissions in the first decades of the 21st century are likely to affect global sea level for centuries, and limiting long-term sea-level rise might require stringent near-term emission reductions.
Image courtesy of Lucy Reading-Ikkanda (artist).
A single formulation combining two gene therapies treated an array of age-related disorders in mice.
Image courtesy of Pixabay/Sipa.
Many ecosystems in the United States may be vulnerable to increased fire occurrence and frequency caused by invasive grasses.
Image courtesy of Pixabay/Stevepb.