Phonon-boundary scattering and thermal transport in Alx Ga1-x N : Effect of layer thickness
(2020) In Applied Physics Letters 117(25).- Abstract
Thermal conductivity of AlxGa1-xN layers with 0 ≤ x ≤ 0.96 and variable thicknesses is systematically studied by combined thermoreflectance measurements and a modified Callaway model. We find a reduction in the thermal conductivity of AlxGa1-xN by more than one order of magnitude compared to that of GaN, which indicates a strong effect of phonon-alloy scattering. It is shown that the short-mean free path phonons are strongly scattered, which leads to a major contribution of the long-mean free path phonons to the thermal conductivity. In thin layers, the long-mean free path phonons become efficiently scattered by the boundaries, resulting in a further decrease in the thermal conductivity. Also, an asymmetry of thermal conductivity as a... (More)
Thermal conductivity of AlxGa1-xN layers with 0 ≤ x ≤ 0.96 and variable thicknesses is systematically studied by combined thermoreflectance measurements and a modified Callaway model. We find a reduction in the thermal conductivity of AlxGa1-xN by more than one order of magnitude compared to that of GaN, which indicates a strong effect of phonon-alloy scattering. It is shown that the short-mean free path phonons are strongly scattered, which leads to a major contribution of the long-mean free path phonons to the thermal conductivity. In thin layers, the long-mean free path phonons become efficiently scattered by the boundaries, resulting in a further decrease in the thermal conductivity. Also, an asymmetry of thermal conductivity as a function of Al content is experimentally observed and attributed to the mass difference between Ga and Al host atoms.
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- author
- Tran, Dat Q. ; Delgado-Carrasco, Rosalia ; Muth, John F. ; Paskova, Tania ; Nawaz, Muhammad ; Darakchieva, Vanya LU and Paskov, Plamen P.
- publishing date
- 2020-12-21
- type
- Contribution to journal
- publication status
- published
- in
- Applied Physics Letters
- volume
- 117
- issue
- 25
- article number
- 252102
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- scopus:85099176672
- ISSN
- 0003-6951
- DOI
- 10.1063/5.0031404
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2020 Author(s).
- id
- 1267af08-a844-4022-baaf-452d7d62cb82
- date added to LUP
- 2025-11-06 16:39:42
- date last changed
- 2025-11-11 15:45:25
@article{1267af08-a844-4022-baaf-452d7d62cb82,
abstract = {{<p>Thermal conductivity of AlxGa1-xN layers with 0 ≤ x ≤ 0.96 and variable thicknesses is systematically studied by combined thermoreflectance measurements and a modified Callaway model. We find a reduction in the thermal conductivity of AlxGa1-xN by more than one order of magnitude compared to that of GaN, which indicates a strong effect of phonon-alloy scattering. It is shown that the short-mean free path phonons are strongly scattered, which leads to a major contribution of the long-mean free path phonons to the thermal conductivity. In thin layers, the long-mean free path phonons become efficiently scattered by the boundaries, resulting in a further decrease in the thermal conductivity. Also, an asymmetry of thermal conductivity as a function of Al content is experimentally observed and attributed to the mass difference between Ga and Al host atoms.</p>}},
author = {{Tran, Dat Q. and Delgado-Carrasco, Rosalia and Muth, John F. and Paskova, Tania and Nawaz, Muhammad and Darakchieva, Vanya and Paskov, Plamen P.}},
issn = {{0003-6951}},
language = {{eng}},
month = {{12}},
number = {{25}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Applied Physics Letters}},
title = {{Phonon-boundary scattering and thermal transport in Al<sub>x </sub>Ga<sub>1-</sub><sub>x </sub>N : Effect of layer thickness}},
url = {{http://dx.doi.org/10.1063/5.0031404}},
doi = {{10.1063/5.0031404}},
volume = {{117}},
year = {{2020}},
}