Please use this identifier to cite or link to this item:
|Title:||Phonon confinement in Ge nanocrystals in silicon oxide matrix|
|Authors:||Jie, Y. |
|Citation:||Jie, Y., Wee, A.T.S., Huan, C.H.A., Shen, Z.X., Choi, W.K. (2011-02-01). Phonon confinement in Ge nanocrystals in silicon oxide matrix. Journal of Applied Physics 109 (3) : -. ScholarBank@NUS Repository. https://doi.org/10.1063/1.3503444|
|Abstract:||Spherical Ge nanocrystals well-dispersed in amorphous silicon oxide matrix have been synthesized with different sizes, and significant size-dependent Raman shift and broadening have been observed. The lattice constant of Ge nanocrystals well-bonded to silicon oxide matrix has been characterized nearly size-independent. With our proposed stress generation and relaxation mechanisms, stress effects in our samples have been analyzed to be insignificant with respect to phonon confinement effects. The phenomenological model introduced by [Richter, Wang, and Ley, Solid State Commun. 39, 625 (1981] with Gaussian weighting function and TO2 phonon dispersion function has been found to give a quite good description of the measured size-dependence of Raman shift and broadening. A 3-peak fitting method has been proposed to determine Ge nanocrystal size and film crystallinity. After physically quantizing quantum-confined one-dimensional elastic waves, we have deduced that each quantum-confined phonon possesses an instantaneous momentum of a given magnitude k with an equal chance of being either positive or negative and momentum conservation is retained in an electron-phonon scattering process. Therefore, on the basis of the first-principle microscopic model and our experimental results, we deduced that Raman scattering in spherical nanocrystals is a concurrent two-phonon process, one phonon generation and one phonon transition. © 2011 American Institute of Physics.|
|Source Title:||Journal of Applied Physics|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Sep 19, 2018
WEB OF SCIENCETM
checked on Sep 5, 2018
checked on Aug 10, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.