High-Field Transport and Noise in p-Si—A First-principles Study

The computation of charge transport properties of semiconductors is now routine owing to advances in the ab-initio description of electron-phonon interactions. To date, most studies have focused on the low-field regime in which the carrier temperature equals the lattice temperature and the power spectral density (PSD) is proportional to the mobility. The calculation of high-field transport and noise properties offers a stricter test of the theory as these relations no longer hold, yet such calculations have not been reported. Here, we compute the high-field mobility and PSD of hot holes in silicon from first principles at temperatures from 80-300 K, electric fields up to 10 kV/cm, and various crystal orientations. We find that one-phonon scattering is sufficient to explain experimental trends. The PSD is found to exhibit a non-monotonic trend with electric field at 80 K which arises from the rapid variation of energy relaxation time with field. Our work highlights the use of high-field transport and noise properties as a rigorous test of the theory of electron-phonon interactions in semiconductors.