Towards a compact model for Schottky-barrier nanotube FETs

Issues pertinent to the development of a compact model for predicting the drain current-voltage characteristics of coaxial-geometry, Schottky-barrier, carbon-nanotube field-effect transistors are discussed. Information on the non-equilibrium barrier shapes at the source-tube and drain-tube contacts is inferred from exact 2-D solutions to Poisson´s equation at equilibrium and Laplace´s equation. This information is then used in a non-equilibrium flux approach to create a model that accounts for tunneling through both barriers and computes the drain current in the case of ballistic transport. For (16,0) tubes and a gate/tube-radius ratio of 10, saturation drain currents of about 1 μm are predicted.