Structural effects on carrier doping in carbon nanotube thin-film transistors

Abstract

Based on density functional theory, we studied the electronic properties of carbon nanotube (CNT) thin films under an external electric field. The carrier accumulation resulting from an electric field depends slightly on the CNT species that form the thin films and their arrangement with respect to the electrode. Although most of the carriers are accumulated in the CNTs located at the electrode side, wave function hybridization between semiconducting CNTs slightly enhances the carrier penetration into the opposite CNT layer. Metallic CNTs strongly depress or enhance the carrier penetration for the thin films when they are located at the electrode side or not, respectively.