S3-P6: A generalized model for characteristics of graphene FETs in various gate biasing configurations with mobility up to 24000 cm2/vs

Among a few novel properties, graphene-based field-effect transistors {GFET} have ambipolar current-voltage (I-V) transfer characteristics that enable hole current or electron current to conduct under varying gate voltage and constant drain bias. Furthermore, the drain current may not simply exhibit a saturation characteristic as seen in all silicon metal oxide semiconductor field-effect transistors (MOSFET). Indeed, in a large number of experiments on GFETs, the I-V characteristics showed a mixed combination of linear, non-linear and saturation behaviors. Here, I-V characteristics in four GFET experiments selected from four different gate-biasing configurations were modeled by a semi-analytical equation and categorized in order of increasing carrier mobility. The results suggested that saturation current may occur in low mobility devices and that linear or nonlinear characteristics are more favorable in devices with higher mobility up to 24000 cm²/Vs. Their modeled transconductance and asymmetric conductance also showed very good agreement with experimental data.