Ab initio calculation of the deformation potentials for intervalley phonons in silicon

The fully self-consistent first-principles calculations of electron scattering from short-wavelength phonons between lower valleys in the conduction band of a silicon crystal are carried out for the first time. The calculations of the lattice constant, the electron and phonon spectra, and the scattering probabilities are performed in the framework of a unified approach within the electron density functional theory. The theory contains no phenomenological assumptions regarding the relative position of minima in the conduction band, effective masses of carriers, interatomic forces, and scattering probabilities. The electron-phonon coupling constants (deformation potentials) for symmetry-allowed f and g transitions are calculated. The calculated constants lie in the range of values measured in different experiments involving intervalley transitions in silicon.