Abstract
Dislocations in III-nitride semiconductors impede heat transport, leading to localized overheating, which severely limits the performance and reliability of optoelectronic and power devices. Current research on phonon–dislocation interactions primarily addresses bulk materials, focusing on the average effects at specific dislocation densities. However, phonon resistance from dislocation scattering arises from both short-range core interactions and long-range strain field interactions, which remain largely unexplored. Here, electron energy-loss spectroscopy is used to investigate a GaN dislocation. Vibrational modes localized on specific core atoms are revealed, reflecting short-range interactions. Additionally, phonon energy shifts driven by strain fields surrounding the dislocation are observed, reflecting long-range interactions. Ab initio calculations support these findings and draw out additional details. This work establishes a paradigm for probing defect-induced phonon scattering at the single-atom level, revealing how dislocations affect phonon behavior through atomic reconstruction and strain engineering, thus offering insights for designing improved material functionalities.
| Original language | English |
|---|---|
| Pages (from-to) | 14279-14285 |
| Number of pages | 7 |
| Journal | Nano Letters |
| Volume | 25 |
| Issue number | 39 |
| DOIs | |
| State | Published - Oct 1 2025 |
Funding
This work was supported by the National Key R&D Program of China (2023YFA1407000), the National Natural Science Foundation of China (62321004, 62104010, 62227817, 62374010, 62450096, and 62374001), the Beijing Natural Science Foundation (Z200004), the Guangdong Major Project of Basic and Applied Basic Research (2023B0303000012), and the Postdoctoral Fellowship Program of CPSF (GZC20252209). This work was supported by the High-Performance Computing Platform of Peking University. The authors acknowledge the Electron Microscopy Laboratory of Peking University for the use of electron microscopes. Calculations and manuscript development (by Lucas R. Lindsay) were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Material Sciences and Engineering Division. The calculations used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract DE-AC05-00OR22725, and resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract DE-AC02-05CH11231.
Keywords
- III-nitride semiconductors
- dislocation
- electron energy-loss spectroscopy
- phonon