Backscattering and common-base current gain of the Graphene Base Transistor (GBT)

In this paper, we investigate electron transport and electron scattering in the insulators of the Graphene Base Transistor (GBT) by means of a Monte Carlo transport model. We focus on electron backscattering in the base-collector insulator as the possible root cause of the large experimental base current and small measured common-base current gain (αF) of GBTs. Different GBT structures have been simulated and the impact of the scattering parameters on the base current is analyzed. Simulated backscattering-limited αF values are found to be much higher than available experimental data, suggesting that state-of-the-art technology is still far from being optimized. However, those simulated αF values can be low enough to limit the maximum achievable GBT performance.