A first principles method to simulate electron mobilities in 2D materials

We examine the predictive capabilities of first-principles theoretical methods to calculate the phonon- and impurity-limited electron mobilities for a number of technologically relevant two-dimensional materials in comparison to experiment. The studied systems include perfect graphene, graphane, germanane and MoS₂, as well as graphene with vacancies, and hydrogen, gold, and platinum adsorbates. We find good agreement with experiments for the mobilities of graphene (μ = 2 × 10⁵ cm² V⁻¹s⁻¹) and graphane (μ = 166 cm² V⁻¹s⁻¹) at room temperature. For monolayer MoS₂ we obtain μ = 225 cm² V⁻¹s⁻¹. This value is higher than what is observed experimentally (0.5–200 cm² V⁻¹s⁻¹) but is on the same order of magnitude as other recent theoretical results. For bulk MoS₂ we obtain μ = 48 cm² V⁻¹s⁻¹. We obtain a very high mobility of 18 200 cm² V⁻¹s⁻¹ for single-layer germanane. The calculated reduction in mobility from the different impurities compares well to measurements where experimental data are available, demonstrating that the proposed method has good predictive capabilities and can be very useful for validation and materials design. (paper)