With device dimensions shrinking toward nanoscale sizes, an accurate understanding and modeling of the thermal energy transfer mechanisms at metal-nonmetal interfaces becomes highly desirable. To model the thermal transport across the Au-GaN interface, we developed a general multitemperature model (MTM) that accounts for both electron and phonon transport and allows for a nonequilibrium phonon population described as a sum of thermal distributions of the phonon branches. The model is populated with material parameters computed from ab initio calculations and used to describe the temperature profile across a Au-GaN junction 400 nm in length subjected to constant temperature differential, continuous-wave laser heating of Au, and constant heat flux on GaN. The calculated steady-state and time-dependent temperature profiles reveal strongly nonequilibrium electron-phonon and phonon-phonon interfacial regions created through energy carrier coupling. Our results indicate that a multitemperature-based model is required for the accurate resolving of the thermal energy flow across metal-nonmetal interfaces. Our MTM will advance the theoretical tool to investigate nonequilibrium thermal transport across metal-nonmetal interfaces.
Bibliographical noteFunding Information:
Simulations were preformed at the Tianhe2-JK of Beijing Computational Science Research Center. Z.T. acknowledges the support by the National Natural Science Foundation (Grant No. 52106068), the China Postdoctoral Science Foundation (Grant No. 2020M680127), the Shenzhen Science and Technology Program (Grant No. RCBS20200714114919142), and the Guangdong Basic and Applied Basic Research Foundation (Grants No. 2020A1515110838 and No. 2021A1515011688). T.F. acknowledges support from DFG FR-2833/7 and the National Natural Science Foundation of China (Grant No. U1930402).
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- ab initio calculations
- Boltzmann transport equation
- heat conduction equation
- metal-nonmetal interface
- multitemperature modeling
- thermal transport