Direct evidence for screening of carrier — Acoustic phonon interaction at low to medium carrier densities in GaAs

Abstract

Direct evidence for screening of the electron (and hole)-piezoelectric acoustic phonon interaction in GaAs even at low to medium carrier densities (1013-1016cm-3) is reported and indications for a partial screening of the carrier-deformation potential interaction are discussed. These conclusions are based on detailed experimental determinations of the dependence of energy dissipation rates of hot carriers on carrier and lattice temperature under steady state conditions and free decay of a hot gas. Different loss mechanisms govern the energy transfer of a hot carrier plasma to the lattice in steady state and in the transient case. Hole-deformation potential scattering and electron-deformation potential scattering, respectively, are the dominant processes in contrast to previous belief. The dissipation rate is more than one order of magnitude larger under continuous excitation.