Electron-phonon interaction and Raman scattering in doped GaAs/AlAs superlattices

Abstract

The Raman scattering spectroscopy method is used to study the interaction of phonons and free charge carriers in doped semiconductor nanostructures (superlattices). In doped superlattices based on polar semiconductors, the collective vibrational modes of free charge carriers (plasmons) shield the long-range Coulomb interaction of cations and anions, which leads to the formation of mixed phononplasmon modes. The angular dispersion (anisotropy) of phonon-plasmon modes in doped GaAs/AlAs superlattices is studied. The observed anisotropy is due to the anisotropy of dielectric permeability in superlattices.