Electric Field And Impurity-Induced Symmetry Forbidden Lo Phonon Raman Scattering In Heavily Doped <100> N-GaAs

We have investigated symmetry forbidden longitudinal optic Raman scattering for various polarization configurations at 4579A from the <100> surface of heavily doped n-GaAs caused by the strong surface-fields and high impurity levels. We have evaluated the magnitude and phase of the coefficient of the electric-field induced term as well as the magnitude of the coefficient of the impurity-induced factor. The former parameter may be very useful for the contactless evaluation of space charge electric fields in GaAs.