Modeling the effective mass and Y-junction rectifying current of carbon nanotubes

We present models for explaining the effective mass and electronic properties of heterojunctions formed by carbon nanotubes of different diameters. We predict the effective mass of a NT and the current of an array of Y-junction NTs based solely on the tube diameters. By investigating the effective mass of small diameter tubes, we find that in addition to the distinction based on chirality of semiconducting NTs, there are two fundamentally different tube types.