Length Dependent Thermal Conductivity Measurements Yield Phonon Mean Free Path Spectra in Nanostructures
Abstract
Thermal conductivity measurements over variable lengths on nanostructures such as nanowires provide important information about the mean free paths (MFPs) of the phonons responsible for heat conduction. However, nearly all of these measurements have been interpreted using an average MFP even though phonons in many crystals possess a broad MFP spectrum. Here, we present a reconstruction method to obtain MFP spectra of nanostructures from variable-length thermal conductivity measurements. Using this method, we investigate recently reported length-dependent thermal conductivity measurements on SiGe alloy nanowires and suspended graphene ribbons. We find that the recent measurements on graphene imply that 70% of the heat in graphene is carried by phonons with MFPs longer than 1 micron.
Additional Information
© 2015 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ Received 29 October 2014; Accepted 19 February 2015; Published 13 March 2015. This work was supported by a start-up fund from the California Institute of Technology and by the National Science Foundation under CAREER Grant CBET 1254213. Author Contributions: H.Z., C.H. and D.D. performed simulations and calculations. H.Z. and A.M. analyzed data. H.Z., A.M., C.H. and D.D. discussed the result. H.Z. and A.M. wrote the main manuscript text.Attached Files
Published - srep09121.pdf
Submitted - 1410.6233v1.pdf
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Additional details
- PMCID
- PMC4357850
- Eprint ID
- 51529
- Resolver ID
- CaltechAUTHORS:20141110-143729775
- Caltech
- NSF
- CBET-1254213
- Created
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2014-11-11Created from EPrint's datestamp field
- Updated
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2022-06-14Created from EPrint's last_modified field