Inelastic light scattering by charge carrier excitations in two-dimensional plasmas: Theoretical considerations

• Published in: Surface science Vol. 98; no. 1; pp. 451 - 468
• Main Authors: Burstein, E., Pinczuk, A., Mills, D.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.1980
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(80)90527-0

We discuss the single particle and collective charge carrier excitations of the two-dimensional plasmas that occur in non-polar semiconductors and the microscopic mechanisms for the resonant inelastic light scattering by the single particle and collective inter-subband excitations. Two limiting cases are analyzed, the “flat-band” model which is a rough approximation to the configuration used by Pinczuk et al., and the “bent-band” model in which Franz—Keldysh effects play an important role, that is an approximation to the configuration used by Abstreiter and Ploog. Unlike Raman scattering by optical phonons, the dominant contributions to the light scattering by the single particle and collective charge carrier excitations come from scattering processes at optical energy gaps, such as the E 0+Δ 0 gap, that directly involve the charge carriers, particularly in non-polar semiconductors. In III–V compound semiconductors sizeable contributions to the inelastic scattering by coupled LO phonon-collective inter-subband excitation modes may be expected to come from electro-optic, deformation potential and Fröhlich scattering processes at the E 1 and E 1+Δ 1 gaps.