Strain and Phonon Confinement in Self-Assembled Ge Quantum DotSuperlattices

Abstract

Raman scattering measurements were carried out in self-assembled Gequantum dot superlattices grown by molecular beam epitaxy. Thecharacteristics of the Ge-Ge, Si-Ge, Si-SiLOC and Si-Si peakswere investigated, especially the Ge-Ge optical phonon frequency shiftwas emphasized, which was tuned by the phonon confinement and straineffects. The experimentally observed frequency shift values of the Ge-Gepeak frequency caused by optical phonon confinement and strain in Gequantum dots were discussed with quantitative calculations.