biostudies-literatureZhang ZNatural Science Foundation of Beijing Municipality (Beijing Natural Science Foundation)National Natural Science Foundation of China (National Science Foundation of China)10436https://www.ebi.ac.uk/biostudies/studies/S-EPMC11608312biostudies-literatureUnknown15(1)Group-III nitride semiconductors such as GaN have various important applications based on their three-dimensional form. Previous work has demonstrated the realization of buckled two-dimensional GaN, which can be used in GaN-based nanodevices. However, the understanding of buckled two-dimensional GaN remains limited due to the difficulties in experimental characterization. Here, for the first time, we have experimentally determined the phonon dispersion of buckled two-dimensional GaN by using monochromatic electron energy loss spectroscopy in conjunction with scanning transmission electron microscopy. A phonon band gap of ~40 meV between the acoustic and optical phonon branches is identified for buckled two-dimensional GaN. This phonon band gap is significantly larger than that of ~20 meV fNature communicationsPhonon dispersion of buckled two-dimensional GaN.PMC11608312No. 62104010No. 62374010No. Z200004Jiang HShen BWang JWang PGao PZhang ZZhang YWang TWang XXu XWang ZLiu FYu YfalsePhonon dispersion of buckled two-dimensional GaN.Group-III nitride semiconductors such as GaN have various important applications based on their three-dimensional form. Previous work has demonstrated the realization of buckled two-dimensional GaN, which can be used in GaN-based nanodevices. However, the understanding of buckled two-dimensional GaN remains limited due to the difficulties in experimental characterization. Here, for the first time, we have experimentally determined the phonon dispersion of buckled two-dimensional GaN by using monochromatic electron energy loss spectroscopy in conjunction with scanning transmission electron microscopy. A phonon band gap of ~40 meV between the acoustic and optical phonon branches is identified for buckled two-dimensional GaN. This phonon band gap is significantly larger than that of ~20 meV f2024-01-01T00:00:00Z2024 Nov2025-04-04T00:21:47.226Z2025-04-04T00:21:47.226ZS-EPMC116083123961615410.1038/s41467-024-54921-8