Confinement and electron-phonon interactions of the E1 exciton in self-organized Ge quantum dots

We have utilized resonant Raman scattering to investigate the phonon modes of self-organized Cc quantum dots grown by molecular-beam epitaxy. Both Ge-Ge and Si-Ge phonon modes are found to exhibit strong enhancements at the E-1 exciton. The strain in the quantum dots deduced from the phonon energies is consistent with the results of high-resolution transmission electron microscopy. An upper bound on the confinement energy of the E-1 exciton in quantum dots was deduced. The enhancement strength in the Si-Ge phonon indicates strong interaction between this mode and the E-1 exciton of the Ge dots. [S0163-1829(99)12403-2].