First-principle-based full-dispersion Monte Carlo simulation of the anisotropic phonon transport in the wurtzite GaN thin film

Journal Article · Thu Apr 14 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4945776· OSTI ID:22594608

Wu, Ruikang; Hu, Run; Luo, Xiaobing ^[1]

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1. State Key Laboratory of Coal Combustion and Thermal Packaging Laboratory, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

In this study, we developed a first-principle-based full-dispersion Monte Carlo simulation method to study the anisotropic phonon transport in wurtzite GaN thin film. The input data of thermal properties in MC simulations were calculated based on the first-principle method. The anisotropy of thermal conductivity in bulk wurtzite GaN is found to be strengthened by isotopic scatterings and reduced temperature, and the anisotropy reaches 40.08% for natural bulk GaN at 100 K. With the GaN thin film thickness decreasing, the anisotropy of the out-of-plane thermal conductivity is heavily reduced due to both the ballistic transport and the less importance of the low-frequency phonons with anisotropic group velocities. On the contrary, it is observed that the in-plane thermal conductivity anisotropy of the GaN thin film is strengthened by reducing the film thickness. And the anisotropy reaches 35.63% when the natural GaN thin film thickness reduces to 50 nm at 300 K with the degree of specularity being zero. The anisotropy is also improved by increasing the surface roughness of the GaN thin film.

• OSTI ID: 22594608
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 14; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
AUGMENTATION
COMPUTERIZED SIMULATION
DISPERSIONS
GALLIUM NITRIDES
MONTE CARLO METHOD
PHONONS
ROUGHNESS
SCATTERING
SURFACES
THERMAL CONDUCTIVITY
THICKNESS
THIN FILMS
TRANSPORT THEORY
VELOCITY