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Thermal conductivity of ScxAl1−xN and YxAl1−xN alloys

Tran, Dat Q. ; Tasnádi, Ferenc ; Žukauskaitė, Agnė ; Birch, Jens ; Darakchieva, Vanya LU and Paskov, Plamen P. (2023) In Applied Physics Letters 122(18).
Abstract

Owing to their very large piezoelectric coefficients and spontaneous polarizations, (Sc,Y) x Al1−xN alloys have emerged as a new class of III-nitride semiconductor materials with great potential for high-frequency electronic and acoustic devices. The thermal conductivity of constituent materials is a key parameter for design, optimization, and thermal management of such devices. In this study, transient thermoreflectance technique is applied to measure the thermal conductivity of ScxAl1−xN and YxAl1−xN (0 ≤ x ≤ 0.22 ) layers grown by magnetron sputter epitaxy in the temperature range of 100-400 K. The room-temperature thermal conductivity of both alloys is found to decrease... (More)

Owing to their very large piezoelectric coefficients and spontaneous polarizations, (Sc,Y) x Al1−xN alloys have emerged as a new class of III-nitride semiconductor materials with great potential for high-frequency electronic and acoustic devices. The thermal conductivity of constituent materials is a key parameter for design, optimization, and thermal management of such devices. In this study, transient thermoreflectance technique is applied to measure the thermal conductivity of ScxAl1−xN and YxAl1−xN (0 ≤ x ≤ 0.22 ) layers grown by magnetron sputter epitaxy in the temperature range of 100-400 K. The room-temperature thermal conductivity of both alloys is found to decrease significantly with increasing Sc(Y) composition compared to that of AlN. We also found that the thermal conductivity of YxAl1−xN is lower than that of ScxAl1−xN for all studied compositions. In both alloys, the thermal conductivity increases with the temperature up to 250 K and then saturates. The experimental data are analyzed using a model based on the solution of the phonon Boltzmann transport equation within the relaxation time approximation. The contributions of different phonon-scattering mechanisms to the lattice thermal conductivity of (Sc,Y) x Al1−xN alloys are identified and discussed.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied Physics Letters
volume
122
issue
18
article number
182107
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:85158020755
ISSN
0003-6951
DOI
10.1063/5.0145847
language
English
LU publication?
yes
id
d3d5eae2-97df-43c9-86bd-0b488c7faff6
date added to LUP
2023-08-11 10:34:02
date last changed
2023-11-08 08:30:27
@article{d3d5eae2-97df-43c9-86bd-0b488c7faff6,
  abstract     = {{<p>Owing to their very large piezoelectric coefficients and spontaneous polarizations, (Sc,Y) x Al<sub>1−x</sub>N alloys have emerged as a new class of III-nitride semiconductor materials with great potential for high-frequency electronic and acoustic devices. The thermal conductivity of constituent materials is a key parameter for design, optimization, and thermal management of such devices. In this study, transient thermoreflectance technique is applied to measure the thermal conductivity of Sc<sub>x</sub>Al<sub>1−x</sub>N and Y<sub>x</sub>Al<sub>1−x</sub>N (0 ≤ x ≤ 0.22 ) layers grown by magnetron sputter epitaxy in the temperature range of 100-400 K. The room-temperature thermal conductivity of both alloys is found to decrease significantly with increasing Sc(Y) composition compared to that of AlN. We also found that the thermal conductivity of Y<sub>x</sub>Al<sub>1−x</sub>N is lower than that of Sc<sub>x</sub>Al<sub>1−x</sub>N for all studied compositions. In both alloys, the thermal conductivity increases with the temperature up to 250 K and then saturates. The experimental data are analyzed using a model based on the solution of the phonon Boltzmann transport equation within the relaxation time approximation. The contributions of different phonon-scattering mechanisms to the lattice thermal conductivity of (Sc,Y) x Al<sub>1−x</sub>N alloys are identified and discussed.</p>}},
  author       = {{Tran, Dat Q. and Tasnádi, Ferenc and Žukauskaitė, Agnė and Birch, Jens and Darakchieva, Vanya and Paskov, Plamen P.}},
  issn         = {{0003-6951}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{18}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Applied Physics Letters}},
  title        = {{Thermal conductivity of Sc<sub>x</sub>Al<sub>1−x</sub>N and Y<sub>x</sub>Al<sub>1−x</sub>N alloys}},
  url          = {{http://dx.doi.org/10.1063/5.0145847}},
  doi          = {{10.1063/5.0145847}},
  volume       = {{122}},
  year         = {{2023}},
}