Ab initio band bending, metal-induced gap states, and Schottky barriers of a carbon and a boron nitride nanotube device

We have characterized the fully self-consistent electronic properties of a prototypical metal/nanotube interface using a combined nonequilibrium Green's function and density-functional-theory-based formalism, under different conditions of gate and bias voltages. Both carbon and boron nitride nanotubes between Al electrodes were considered. The electronic properties of the interface are dominated both by a dipole and by metal-induced gap states formed through the transfer of charge between the metal and the nanotube. In addition, first-principles estimates-within the local density approximation-of the Schottky barrier heights are given.