Theory of hot-electron energy loss in polar semiconductors: Role of plasmon-phonon coupling

The theory for hot-electron relaxation in bulk III-V semiconductors is developed within a many-body formalism by considering energy loss to optical and acoustic phonons, with special emphasis on the influence of the plasmon-phonon coupling phenomenon. The effects of quantum statistics, screening, hot phonons, and acoustic phonons are quantified in order to assess their relative physical importance. We find that for low-electron-density samples there is a temperature range in which it is essential to include plasmon-phonon coupling in the theory, and predict how this effect will manifest itself experimentally. Our theoretical results are in good agreement with the available experimental data in GaAs and GaxIn1-xAs.