Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions

Phonon relaxation time and free path distributions are reconstructed from experimental measurements on a two-dimensional transient thermal grating and compared with density functional theory (DFT) results for silicon. The reconstruction is performed using the inverse problem formulation of Forghani...

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Main Authors: Forghani Oozroody, Mojtaba, Hadjiconstantinou, Nicolas
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Language:English
Published: AIP Publishing 2020
Online Access:https://hdl.handle.net/1721.1/126434
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author Forghani Oozroody, Mojtaba
Hadjiconstantinou, Nicolas
author2 Massachusetts Institute of Technology. Department of Mechanical Engineering
author_facet Massachusetts Institute of Technology. Department of Mechanical Engineering
Forghani Oozroody, Mojtaba
Hadjiconstantinou, Nicolas
author_sort Forghani Oozroody, Mojtaba
collection MIT
description Phonon relaxation time and free path distributions are reconstructed from experimental measurements on a two-dimensional transient thermal grating and compared with density functional theory (DFT) results for silicon. The reconstruction is performed using the inverse problem formulation of Forghani et al. [Phys. Rev. B 94, 155439 (2016)]. The discrepancies observed between reconstructed and DFT results are analyzed in terms of the ability of each set of data to reproduce the experimental temperature relaxation profiles; the reconstructed data are found to predict temperature profiles in closer agreement with the experimental data than the DFT results, possibly due to discrepancies between the actual material and the idealized model studied in the DFT calculations. The reconstructed phonon properties accurately predict temperature relaxation profiles at grating length scales smaller than those spanned by the experimental data. This is a very important feature since in a variety of experimental setups, including the one providing the data in the present study, measurements are not available at all scales spanned by the material free paths. ©2019 Author(s).
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spelling mit-1721.1/1264342022-09-28T12:47:14Z Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions Forghani Oozroody, Mojtaba Hadjiconstantinou, Nicolas Massachusetts Institute of Technology. Department of Mechanical Engineering Phonon relaxation time and free path distributions are reconstructed from experimental measurements on a two-dimensional transient thermal grating and compared with density functional theory (DFT) results for silicon. The reconstruction is performed using the inverse problem formulation of Forghani et al. [Phys. Rev. B 94, 155439 (2016)]. The discrepancies observed between reconstructed and DFT results are analyzed in terms of the ability of each set of data to reproduce the experimental temperature relaxation profiles; the reconstructed data are found to predict temperature profiles in closer agreement with the experimental data than the DFT results, possibly due to discrepancies between the actual material and the idealized model studied in the DFT calculations. The reconstructed phonon properties accurately predict temperature relaxation profiles at grating length scales smaller than those spanned by the experimental data. This is a very important feature since in a variety of experimental setups, including the one providing the data in the present study, measurements are not available at all scales spanned by the material free paths. ©2019 Author(s). Solid-State Solar-Thermal Energy Conversion Center (S3TEC), an Energy Frontier Research Center funded by the DOE (Award No. DE-SC0001299) Solid-State Solar-Thermal Energy Conversion Center (S3TEC), an Energy Frontier Research Center funded by the DOE (award no. DE-FG02-09ER46577) 2020-07-29T21:43:04Z 2020-07-29T21:43:04Z 2019-01 2018-09 2020-07-17T18:04:01Z Article http://purl.org/eprint/type/JournalArticle 1077-3118 https://hdl.handle.net/1721.1/126434 Forghani, Mojtaba and Nicolas G. Hadjiconstantinou, "Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions." Applied Physics Letters 114, 2 (January 2019): no. 023106 doi. 10.1063/1.5062846 ©2019 Author(s) en https://dx.doi.org/10.1063/1.5062846 Applied Physics Letters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf AIP Publishing MIT web domain
spellingShingle Forghani Oozroody, Mojtaba
Hadjiconstantinou, Nicolas
Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title_full Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title_fullStr Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title_full_unstemmed Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title_short Phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
title_sort phonon relaxation time reconstruction from transient thermal grating experiments and comparison with density functional theory predictions
url https://hdl.handle.net/1721.1/126434
work_keys_str_mv AT forghanioozroodymojtaba phononrelaxationtimereconstructionfromtransientthermalgratingexperimentsandcomparisonwithdensityfunctionaltheorypredictions
AT hadjiconstantinounicolas phononrelaxationtimereconstructionfromtransientthermalgratingexperimentsandcomparisonwithdensityfunctionaltheorypredictions