Exceptionally high hole mobilities in monolayer group-IV monochalcogenides GeTe and SnTe

Two-dimensional semiconductors are considered as promising channel materials for next-generation nanoelectronics devices, while their practical applications typically limited by low mobilities. In this work, using first-principles calculations combined with the Boltzmann transport formalism involving electron–phonon coupling, we study properties of monolayer group-IV monochalcogenides (MX, M = Ge, Sn; X S, Se, and Te). We find that GeTe SnTe possess exceptionally high hole mobilities, which even reach 835 1383 cm2/V s, respectively, at room temperature. More interestingly, mobilities increase in atomic number “X” MXs when “M” remains same. Such a trend is mainly due to increased group velocity decreased density states, latter plays significant role determining carrier scattering space relaxation time. Meanwhile, different from acoustic deformation potential theory, high-energy optical phonons contribute lot scattering. Our work shows p-type reveals intrinsic connection between phonons, charge mobility, would shed light on exploring two-dimensional mobility.