Graphene-Based Bipolar Junction Transistor

Graphene was considered likely to revolutionize the electronics industry. This expectation has not yet been fulfilled, mainly due to the non-ideal characteristics of graphene-based transistors. Here, we propose a novel graphene-based structure as a graphene-based bipolar junction transistor (G-BJT), a nanoscale transistor which has the ideal characteristics of the common BJT transistor. In this device, N-P-N regions are formed in the graphene channel by applying voltages to the three gates. The carrier concentrations, energy band diagrams, and current-voltage curves are measured and presented. The base-emitter junction shows a rectifying behavior with the ideality factor in the range of (2.8-3.2), the built-in potential of 0.38V, and the saturation current of 10(-12) A. The G-BJT provides a minimum current gain of 20 at the base-width of 10 nm, a feature that cannot be easily obtained in Si-based BJTs. Interestingly, the current gain(beta) can be controlled by the gate voltages in G-BJT and changes by 26.5% compared to the maximum value, which leads to the controllability of this proposed transistor. Identical BJT behavior, scalability down to nanometer range, large carrier mobility, along the controllable current gain of G-BJT make this transistor a good candidate for the next generation of the nanoelectronics industry.