Electron-phonon scattering and ballistic behavior in semiconducting carbon nanotubes

We study the steady-state and ballistic transport properties of semiconducting zig-zag carbon nanotubes (CNTs) using semiclassical Monte Carlo simulation. Electron-phonon scattering is the only type of interaction included in the model. The band structure and phonon dispersion are derived from that of graphene by the zone folding method. Steady-state drift velocity and low-field mobility are calculated for CNTs with wrapping index ranging from n=10 to n=59, i.e., for a diameter range of 0.78−4.62nm. Principally, a transient analysis of transport under uniform driving field is realized and gives the fraction of ballistic electrons as a function of CNT length and the mean free path (MFP) for acoustic and optical phonons scattering. The probability to have ballistic electrons on a given distance appears to be higher for nanotubes of large diameter and depends on the field applied.