Electrically doped 2D material tunnel transistor

Gate controlled tunnel junctions wherein the PN-junction like potential profile is made by two gates with opposite polarities are currently dominant in the fabrication of 2D material devices. Electrical doping methods are also preferred in tunnel field-effect transistors (TFETs) as chemical doping introduces states within the bandgap of the semiconductor and therefore degrades the OFF-state performance of TFETs. Moreover, low band gap 2D materials are preferable for high performance TFETs. Consequently, bilayer graphene (BLG) TFET is studied in this work. The critical design parameters in the performance of low bandgap electrically doped 2D transistors are investigated here. Through atomistic simulations, it is shown that the key element in the performance of electrically gated junctions is the thickness of the oxide even when the top and bottom gates have different biases. But still the equivalent oxide thickness (EOT) cannot be disregarded completely since it determines the value of the electric field dependent band gap in BLG.