Role of thermalizing and nonthermalizing walls in phonon heat conduction along thin films
Abstract
Phonon boundary scattering is typically treated using the Fuchs-Sondheimer theory, which assumes that phonons are thermalized to the local temperature at the boundary. However, whether such a thermalization process actually occurs and its effect on thermal transport remains unclear. Here we examine thermal transport along thin films with both thermalizing and nonthermalizing walls by solving the spectral Boltzmann transport equation for steady state and transient transport. We find that in steady state, the thermal transport is governed by the Fuchs-Sondheimer theory and is insensitive to whether the boundaries are thermalizing or not. In contrast, under transient conditions, the thermal decay rates are significantly different for thermalizing and nonthermalizing walls. We also show that, for transient transport, the thermalizing boundary condition is unphysical due to violation of heat flux conservation at the boundaries. Our results provide insights into the boundary scattering process of thermal phonons over a range of heating length scales that are useful for interpreting thermal measurements on nanostructures.
Additional Information
© 2016 American Physical Society. Received 5 November 2015; revised manuscript received 31 December 2015; published 28 January 2016. N.K.R. would like to thank the Resnick Sustainability Institute at Caltech and the Dow Chemical Company for fellowship support. A.J.M. was supported by the National Science Foundation under Grant No. CBET CAREER 1254213.Attached Files
Published - PhysRevB.93.035314.pdf
Submitted - 1511.03312v1.pdf
Supplemental Material - Supplementary_Material_V1.pdf
Files
Additional details
- Alternative title
- The Role of Thermalizing and Non-thermalizing Walls in Phonon Heat Conduction along Thin Films
- Eprint ID
- 64284
- Resolver ID
- CaltechAUTHORS:20160205-142512254
- Resnick Sustainability Institute
- Dow Chemical Company
- NSF
- CBET 1254213
- Created
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2016-02-05Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute