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 <i>p</i>-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 <i>ab initio</i> 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 <i>p</i>-channel electronics and point to spin-orbit engineering as a key strategy for the design of high-mobility semiconductors.