First-principles Study of the Electron and Hole Mobility in Silicane

Abstract

Silicane, hydrogen-terminated monolayer hexagonal silicon, as illustrated in Fig. 1, is a two-dimensional (2D) material and a candidate for future nanoscale electronic devices. To assess its promise, we conduct a theoretical study of the electron and hole mobility in silicane starting from first principles. We pay special attention to the out-of-plane phonon (ZA) mode, which is known to strongly suppress mobility in 2D materials with broken mirror symmetry [1]. First, we use density functional theory (DFT) to obtain silicane properties. Next, the scattering rates are determined and the impact of scattering with various phonon branches is analyzed. Finally, the electron and hole mobility are calculated using full band Monte-Carlo calculations.