Electronic and magneto-transport in chirality sorted carbon nanotube films

Abstract

This research details electronic and magneto-transport in unsorted and chirality-enriched carbon nanotube (CNT) films. By measuring the electrical conductivity from 4 K to 297 K, we were able to assign the governing mechanism of electronic transport. Fluctuation-induced tunnelling was in accordance with the obtained data and very well matched the underlying physics. We demonstrated how a change in the type of CNT to make the film affects its electrical performance. As the temperature was decreased down to cryogenic conditions, up to a 56-fold increase in resistance was noted. Moreover, the measurement of magnetoresistance (MR) revealed a non-monotonic dependence on the applied magnetic field. The initial negative component of MR was eventually overpowered by the positive MR component as the field strength was increased beyond a certain threshold.

Thermoelectric Properties of Thin Films from Sorted Single-Walled Carbon Nanotubes

“…16% decrease in electrical conductivity as the temperature of the m-SWCNT film was increased beyond 100 °C. What regards the behavior of s-SWCNTs, as the temperature is elevated, thermal energy facilitates the promotion of the charge carriers to the conduction band [ 46 ], which makes the material more conductive. Hence, a 37% improvement was observed for s-SWCNTs when the SWCNT network operated at high temperatures.…”

Effective Doping of Single-Walled Carbon Nanotubes with Polyethyleneimine

“…Besides the extrinsic phenomenon of contact resistance, intrinsic components hamper the charge propagation through the SWCNT network. The presence of crystal defects in the form of functional groups or dislocations substantially impacts the ability of the material to transfer electrical, thermal, and mechanical energy [ 35 ]. A straightforward method to gauge the level of imperfection in nanocarbon materials is Raman spectroscopy.…”

Doping of carbon nanotubes by halogenated solvents

“…Lastly, in all cases, as the temperature was increased, the electrical conductivity decreased, revealing that the SWCNT networks were of predominantly metallic character 32 . Due to this fact, the values of the Seebeck coefficients of differently prepared SWCNT films were satisfactory but not exceptional.…”