Theoretical and experimental Raman study of superlattices with GeSi quantum dots
V. Lashkaryov Institute of Semiconductor Physics, National Acad. Sci. of Ukraine, 03028 Kyiv, Ukraine
Corresponding author: email@example.com
Revised: 23 November 2009
Published online: 9 March 2010
The results of the theoretical and experimental study of Raman scattering in the quantum dot (QD) multilayers are reported. In order to obtain an adequate description of the structure with QDs and correctly explain the experimental Raman spectra, a model is proposed which takes into account the real crystal structure of both the QD and surrounding matrix, as well as the QD-matrix interaction. The secondary quantisation and Green function method were used in the theoretical calculation model. The results obtained show that crystal structures with matrix-embedded QDs can be described as a mixed crystal with specific distribution of "impurities" organised in large "molecules". A qualitative agreement in position and intensity of bands between the calculated and experimental Raman spectra for multilayer Ge/Si QD crystal structure is observed, the doublet character of the bands is explained.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010