Random stick network analysis of electronic transport in carbon nanotube thin films

Electronic transport in metallic carbon nanotube (CNT) thin films is investigated theoretically using a random stick network analysis combined with circuit theory. To discuss the dependence of the sheet conductance on the CNT alignment in the films, an angle φ max ( ) is introduced as a new parameter to characterize the CNT alignment: φ max = 0° and φ max = 90° correspond to perfectly aligned and perfectly random network structures, respectively. The results indicate that the conductance exhibits a maximum around φ max = 55°. In addition, the conductance shows a local minimum around φ max = 30° because CNTs tend to intersect with incommensurate junctions that have a high contact resistance.