This work investigates the phonon properties such as phonon dispersion relation, average group velocity, and phonon density of state (DOS) theoretically in GaN nanofilm under various surface stress fields. By taking into account of the surface energy effects, the elasticity theory is presented to describe the confined phonons of nanofilms with different surface stresses. The calculation results show that the influence of surface stress on the phonon properties depends on the thickness of nanofilm. The negative surface stress leads to a higher average group velocity and corresponding lower phonon DOS. The positive surface stress has the opposite effect. The significant modification of thermal properties, e.g., phonon thermal conductivity, in GaN nanofilms is mostly stemmed from the change of phonon average group velocity and DOS by surface stress. These results suggest that the thermal or electrical properties in GaN nanofilms could be enhanced or reduced by tuning the surface stress acting on the films.
Effects of Surface Stress on the Phonon Properties in GaN Nanofilms
School of Aeronautics and Astronautics,
Hangzhou, Zhejiang 310027, China
Contributed by the Applied Mechanics Division of ASME for publication in the JOURNAL OF APPLIED MECHANICS. Manuscript received May 11, 2015; final manuscript received July 23, 2015; published online August 10, 2015. Assoc. Editor: Daining Fang.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Luo, H., and Zhu, L. (August 10, 2015). "Effects of Surface Stress on the Phonon Properties in GaN Nanofilms." ASME. J. Appl. Mech. November 2015; 82(11): 111002. https://doi.org/10.1115/1.4031150
Download citation file:
- Ris (Zotero)
- Reference Manager