About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Matryoshka Phonon Twinning in α-GaN |
Author(s) |
Bin Wei, Qingan Cai, Qiyang Sun, Yaokun Su, Ayman H. Said, Doug L. Abernathy, Jiawang Hong, Chen Li |
On-Site Speaker (Planned) |
Chen Li |
Abstract Scope |
Understanding lattice dynamics is crucial for effective thermal management in high-power electronic devices because phonons dominate thermal transport in most semiconductors. This study utilizes complementary inelastic X-ray and neutron scattering and reports the temperature-dependent phonon dynamics of α-GaN, one of the most important third-generation power semiconductors. A prominent Matryoshka phonon dispersion is discovered with the scattering tools and confirmed by the first-principles calculations. Such Matryoshka twinning throughout the reciprocal space is demonstrated to amplify the phonon anharmonicity through creating abundant three-phonon scattering channels and cutting the phonon lifetime of affected modes by 50%. Such phonon topology effectively contributes to the reduction of the in-plane thermal transport, thus the anisotropic thermal conductivity of α-GaN. The results not only have significant implications for engineering the thermal performance and phonon-related properties of α-GaN, but also offer valuable insights on the role of anomalous phonon topology in thermal transport of other technically important semiconductors. |
Proceedings Inclusion? |
Planned: |
Keywords |
Other, Electronic Materials, Modeling and Simulation |