Raman investigation of anharmonicity and disorder-induced effects in Zn1-xBexSe epifilms
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
69
Journal Issue
7
Pages
075204-1 - 075204-6
Date Issued
2004
Author(s)
Abstract
Raman scattering of Zn1-xBexSe epifilms grown by molecular beam epitaxy on GaAs (001) substrates has been investigated. The effect of compositional disorder was obtained by analyzing the broadening and asymmetry of the first-order LO mode. It is found that the Raman line shapes for the ZnSe-like LO mode in Zn1-xBexSe alloys can be well described by the spatial correlation model. We have also analyzed comparatively the anharmonic effects due to temperature and compositional fluctuations in ZnSe and ZnBeSe systems, using temperature-dependent Raman-scattering measurements. It is found that the anharmonicity is higher for ZnBeSe alloys than ZnSe and it increases with compositional disorder. Therefore, both temperature- and compositional-fluctuation-induced anharmonicities can introduce changes in the linewidth, line center position, and anharmonic decay time of the first-order optical phonons in Zn1-xBexSe alloys. © 2004 The American Physical Society.
Publisher
American Physical Society
Type
journal article