Width Effects in ballistic graphene nanoribbon FETs

In this work, we utilize a full real-space quantum transport simulator using non-equilibrium Green´s Function (NEGF) approach self-consistently coupled to a 3D Poisson´s solver for treating the electrostatics. Using this model, the ballistic performance of double-gate armchair GNR MOSFETs and armchair GNR SB FETs with different types of the contacts and the regular metal with the constant density of states is evaluated. The details of the device structure are shown. The width dependence of these different types of armchair GNR FETs on the device performance, in terms of the subthreshold swing (SS), the drain-induced-barrier-lowering (DIBL), ON-current, the device delay (tau), and power-delay-product (PDP), are investigated. Our simulation results show that the device performance is limited by the tunneling currents which depend on EG, controlled by the GNR width. As shown in Fig. 3 and Fig. 4, among these different transistor types, GNR MOSFETs (infinite semiconducting conducts) always have the best performance.