Surface Phonons Studied by Raman Scattering in GaN Nanostructures
Abstract
We study Raman scattering from surface phonon polaritons in regularly arrayed GaN nanowalls and nanocolumns. The surface phonon mode around 705 cm-1 decreases in intensity with increasing wall width w under a constant interval period p = 355 nm in the nanowalls, and it disappears in the film. This suggests that the interaction between them on the adjacent walls works so as to satisfy the selection rule in the film. The Raman peak from the surface phonon polariton in the nanocolumns is much broader than that in the nanowalls. It decreases in intensity and increases in width with decreasing column diameter d, and it is not observed when d = 75 nm. This behavior is discussed in terms of the quantization of the azimuthal wave vector of a surface phonon polariton on the circumference of the columnar structure. The Raman spectrum of the surface phonon polariton in the regularly arrayed GaN nanocolumns is compared with that of the Fröhlich mode in irregularly arrayed ones.
- Publication:
-
Journal of the Physical Society of Japan
- Pub Date:
- July 2017
- DOI:
- 10.7566/JPSJ.86.074602
- Bibcode:
- 2017JPSJ...86g4602S