Guidelines for accurate and efficient calculations of mobilities in two-dimensional semiconductors

Emerging two-dimensional (2D) materials bring unprecedented opportunities for electronic applications. The design of high-performance devices requires an accurate prediction of carrier mobility in 2D materials, which can be obtained using state-of-the-art ab initio calculations. However, various factors impact the computational accuracy, leading to contradictory estimations for the mobility. Targeting accurate and efficient ab initio calculations for nonmagnetic materials, transport properties in III-V monolayers are reported using the Boltzmann transport equation, and the influences of the pseudopotential, quadrupole correction, Berry connection, and spin-orbit coupling (SOC) on mobilities are systematically investigated in this work. Our findings are as follows: (1) The inclusion of semicore states in pseudopotentials is important to obtain accurate calculations. (2) The variations induced by dynamical quadrupole and Berry connection when treating long-range fields can be 40% and 10%, respectively. (3) The impact of SOC can reach up to 100% for materials with multipeak bands. Importantly, although SOC notably modifies the electronic wave functions, it negligibly impacts the dynamical matrices and scattering potential variations. As a result, the combination of a fully relativistic electron calculation and a scalar-relativistic phonon calculation can strike a good balance between accuracy and cost. This work compares computational methodologies, providing guidelines for accurate and efficient calculations of mobilities in 2D semiconductors.