Intrinsic Charge Transport in Stanene: Roles of Bucklings and Electron–Phonon Couplings

Abstract

The intrinsic charge transport of stanene is investigated by using density functional theory and density functional perturbation theory coupled with Boltzmann transport equations at the first-principles level. The Wannier interpolation scheme is applied to calculate the charge carrier scatterings with all branches of phonons considering dispersion for the whole range of the first Brillouin zone. The intrinsic electron and hole mobilities are calculated to be (2–3) × 103 cm2 V−1 s−1 at 300 K. It is found that the intervalley scatterings from the out-of-plane and the transverse acoustic phonon modes dominate the carrier transport process. By contrast, the mobilities obtained by the conventional deformation potential approach are found to be as large as (2–3) × 106 cm2 V−1 s−1 at 300 K, in which the longitudinal acoustic phonon scattering in the long wavelength limit is assumed to be the dominant scattering mechanism. The inadequacy of the deformation potential approximation in stanene is attributed to the buckling in its honeycomb structure, which originates from the sp2–sp3 orbital hybridization and breaks the planar symmetry. This paper further proposes a strategy to enhance carrier mobilities by suppressing the out-of-plane vibrations through clamping by a substrate.