Disorder-induced electron localization and electronic states coupling in nitride semiconductors
The electronic states of surface oxidized nitride semiconductors (GaN, AlGaN, and AlN) are investigated by valence electron energy-loss spectroscopy. It is shown that the loss of long-range atomic order in the surface oxide produces localized electronic states below the surface states in the bandgap. Using an off-axis electron probe, the coupling between local electronic states and localized states in the amorphous layers of GaN, AlGaN, and AlN is studied. Regarding the excitation of surface states under aloof conditions via long-range electrostatic forces, the surface and the localized states are independent of the electron scattering vector. Interestingly, though the surface sub-bandgap transitions are directionally forbidden, localized states show dispersion due to states coupling between bulk electronic states and localized states. These findings challenge the conventional model of built-in potential barriers at surface oxides and should be useful in understanding the local electrical properties of nano-scale structures.
Authors
- Yong Deng (ORCID: https://orcid.org/0000-0002-8804-9428)
- Nan Xie
- Yi Huang (ORCID: https://orcid.org/0000-0002-8620-8456)
- P. Ruterana (ORCID: https://orcid.org/0000-0001-7356-8850)
- Thomas Walther (ORCID: https://orcid.org/0000-0002-2892-8949)
- Yang Qiu
- Veerendra C. Angadi (ORCID: https://orcid.org/0000-0002-0538-4483)
- Xiaoyi Wang (ORCID: https://orcid.org/0000-0002-7616-8139)
- F. Xu
- Xin Zhang (ORCID: https://orcid.org/0000-0002-1460-3676)
- Jian MA
- Wenyu Hu
- Wenbin Qiu
- Xudong Cui
- Huiyun Liu
- Longqing Chen
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of Electronic Science and Technology of China (CN)
- Peking University (CN)
- Chengdu University of Information Technology (CN)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- State Ethnic Affairs Commission (CN)
- Southern University of Science and Technology (CN)
- Chengdu University of Technology (CN)
- Laboratoire de Physique Corpusculaire de Caen (FR)
- Centre de Recherche sur les Ions, les Matériaux et la Photonique (FR)
- University College London (GB)
- Wuxi Institute of Technology (CN)
- University of Sheffield (GB)
Publication Details
- Journal
- Applied Physics Letters
- Published
- 2025-12-22
- DOI
- https://doi.org/10.1063/5.0299514
- Primary Topic
- Electron and X-Ray Spectroscopy Techniques
- Type
- article
- Field-Weighted Citation Impact
- 0.00