Ultrahigh Hole Mobility in Monolayer WSe2 Enabled by Spin-Orbit Suppression of Intervalley Scattering.

Monolayer WSe2 has recently emerged as a leading candidate for ultrascaled p-channel transistors, with record room-temperature hole mobilities exceeding 1000 cm2/(V s). Here, we reveal the microscopic origin of this exceptional performance using state-of-the-art ab initio Boltzmann transport calculations, incorporating GW quasiparticle corrections and long-range dipole and quadrupole corrections for two-dimensional materials. We obtained a phonon-limited hole mobility of 931 cm2/(V s) at room temperature, in excellent agreement with experiments. We find that this exceptionally high mobility results from the combined suppression of K-K and K-K' scattering by spin-orbit-induced valley splitting and spin-valley locking, together with intrinsically weak polar and piezoelectric interactions. These results position monolayer WSe2 as a front-runner for next-generation high-mobility p-channel electronics and point to spin-orbit engineering as a key strategy for the design of high-mobility semiconductors.