Electron-phonon scattering and ballistic behavior in semiconducting carbon nanotubes

Abstract

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.

Monte Carlo Modeling of Schottky Contacts on Semiconducting Carbon Nanotubes

“…It should be noted that impurity scattering is not included in the simulation. We only consider here the phonon scattering [3,4]. Moreover, the shape of the curves and the current magnitude are in fairly good agreement with experimental results plotted in Fig.…”

“…However, source and drain electrodes of CNTFET are often Schottky contacts. We have developed a transport model appropriate for studying semiconducting CNT [3] and used our Monte Carlo (MC) device simulator to evaluate performance of CNTFET with ohmic source-drain [4]. In this paper, we present first results related to MC simulation of Schottky contacts on CNT, as schematized in Fig.…”

Analysis of CNTFET physical compact model

“…The 2D-Brillouin zone of the nanotube unit cell is a rectangle in the reciprocal space defined by the vectors The band structure of the rolled-up nanotube can be obtained by zone-folding the band structure of the graphene sheet. The zone-folding method used in this work is similar to that presented in [14] extended to all chiralities and diameters. It gives reasonable predictions for the band structure for radii larger than 6 Å [15].…”

Semiclassical and Quantum Transport in CNTFETs Using Monte Carlo Simulation

“…We have developed an MC code to simulate the semiclassical transport in CNTs [19]- [21]. The analytical dispersion relation is used to describe the nanotube subbands, and electron-phonon scattering is included through acoustic, optical, and radial breathing phonon modes [17], [19], [22].…”