Electrostatics of nanowire transistors

The charge transfer doping in metal wire-carbon nanotube junctions has been demonstrated to be important before. In this paper, we investigate the effect of contact geometry, metal work function and insulator dielectric constant on the charge transfer doping into a nanowire channel. We then explore the effect of charge transfer doping on the operation of nanowire transistors. We show that the nanowire transistors with large gate underlap can still deliver an appreciable amount of on-current, which provides a possible explanation for a recent experiment by Javey et al. At the same time, charge transfer doping also imposes constraints on the transistor design.