In this work, high field carrier transport in two dimensional (2D) graphene is investigated. Analytical models are applied to estimate the saturation currents in graphene, based on the high scattering rate of optical phonon emission. Non-equilibrium
(hot) phonon effect was studied by Monte Carlo (MC) simulations. MC simulation confirms that hot phonon effects play a dominant role in current saturation in graphene. Current degradation due to elastic scattering events is much smaller compared to the hot phonon effect. Transient phenomenon as such as velocity overshoot was also studied using MC simulation. The simulation results shows promising potential for graphene to be used in high speed electronic devices by shrinking the channel length below 100nm if electrostatic control can be exercised in the absence of a band gap.
The transport properties of carriers in semiconducting graphene nanoribbons are studied by comparing the effects of phonon, impurity, and line-edge roughness scattering. It is found that scattering from impurities located at the surface of nanoribbon
s, and from acoustic phonons are as important as line edge roughness scattering. The relative importance of these scattering mechanisms varies with the temperature, Fermi level location, and the width of the ribbons. Based on the analysis, strategies for improvement of low-field mobility are described.
