Ab initio electron mobility and polar phonon scattering in GaAs

In polar semiconductors and oxides, the long-range nature of the electron-phonon (e-ph) interaction is a bottleneck to compute charge transport from first principles. Here, we develop an efficient ab initio scheme to compute and converge the e-ph relaxation times (RTs) and electron mobility in polar materials. We apply our approach to GaAs, where by using the Boltzmann equation with state-dependent RTs, we compute mobilities in excellent agreement with experiment at 250-500K. The e-ph RTs and the phonon contributions to intravalley and intervalley e-ph scattering are also analyzed. Our work enables efficient ab initio computations of transport and carrier dynamics in polar materials.