Behaviour of hot electrons under the dc field in chiral carbon nanotubes

TL;DR

This paper theoretically investigates hot electron behavior in chiral carbon nanotubes under a dc electric field, revealing negative differential conductivity at low fields and potential for terahertz radiation generation.

Contribution

It presents a semi-classical analysis of hot electron transport in chiral CNTs, highlighting differences from achiral CNTs and implications for terahertz applications.

Findings

Negative differential conductivity occurs at about 6 kV/cm in chiral CNTs.

Switch from NDC to PDC happens at lower fields in chiral CNTs.

Potential for terahertz radiation generation at low electric fields.

Abstract

Behaviour of hot electrons under the influence of dc field in carbon nanotubes is theoretically considered. The study was done semi-classically by solving Boltzmann transport equation with the presence of the hot electrons source to derive the current densities. Plots of the normalized axial current density versus electric field strength of the chiral CNTs reveal a negative differential conductivity (NDC). Unlike achiral CNTs, the NDC occurs at a low field about $\mathrm{6\ kV/cm}$ for chiral CNT. We further observed that the switch from NDC to PDC occurs at lower dc field in chiral CNTs than achiral counterparts. Hence the suppression of the unwanted domain instability usually associated with NDC and a potential generation of terahertz radiations occurs at low electric field for chiral CNTs.