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Matryoshka Phonon Twinning in alpha-GaN
- Source :
- COMMUNICATIONS PHYSICS 2021
- Publication Year :
- 2021
-
Abstract
- 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 techniques and reports the temperature-dependent phonon dynamics of alpha-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 three-dimension reciprocal space is demonstrated to amplify the anharmonicity of the related phonon modes through creating abundant three-phonon scattering channels and cutting the phonon lifetime of affected modes by more than 50%. Such phonon topology effectively contributes to the reduction of the in-plane thermal transport, thus the anisotropic thermal conductivity of alpha-GaN. The results not only have significant implications for engineering the thermal performance and other phonon-related properties of alpha-GaN, but also offer valuable insights on the role of anomalous phonon topology in thermal transport of other technically important semiconductors.<br />Comment: 34 pages, 15 figures
- Subjects :
- Condensed Matter - Materials Science
Subjects
Details
- Database :
- arXiv
- Journal :
- COMMUNICATIONS PHYSICS 2021
- Publication Type :
- Report
- Accession number :
- edsarx.2106.10922
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1038/s42005-021-00727-9