  We study the electron-phonon relaxation (dephasing) rate in disordered
semiconductors and low-dimensional structures. The relaxation is determined by
the interference of electron scattering via the deformation potential and
elastic electron scattering from impurities and defects. We have found that in
contrast to the destructive interference in metals, which results in the
Pippard ineffectiveness condition for the electron-phonon interaction, the
interference in semiconducting structures substantially enhances the effective
electron-phonon coupling. The obtained results provide an explanation to energy
relaxation in silicon structures.
