Impact of the hot phonon effect on electronic transport in monolayer silicene

Abstract

The hot phonon effect is a non-equilibrium phenomenon that has an important role in high-field electronic transport in two-dimensional electron gases and in 2D materials like graphene. In this work, the influence of this effect on the electronic transport properties of silicene is investigated by means on an ensemble Monte Carlo simulator that accounts self-consistently for the out-of-equilibrium phonon population and the scattering events under high electric field conditions. In this way, the observed reduction in the carrier drift velocity is analyzed in terms of the microscopic scattering events, wavevector distributions, net phonon emission and phonon temperatures. A comparison with the case of graphene is also carried out, showing that despite the similarities concerning the linear bandstructure near the Dirac points, the hot phonon effect is less dominant in silicene due to the differences in the phonon branches and electron–phonon couplings. Even so, neglecting the role of an out-of-equilibrium phonon population may overestimate the high-field drift velocity in silicene up to 25% at moderate carrier concentrations.