Influence ofO2andN2on the conductivity of carbon nanotube networks

Abstract

We have performed experiments on single-wall carbon nanotube ͑SWNT͒ networks and compared with density-functional theory ͑DFT͒ calculations to identify the microscopic origin of the observed sensitivity of the network conductivity to physisorbed O 2 and N 2 . Previous DFT calculations of the transmission function for isolated pristine SWNTs have found physisorbed molecules have little influence on their conductivity. However, by calculating the four-terminal transmission function of crossed SWNT junctions, we show that physisorbed O 2 and N 2 do affect the junction's conductance. This may be understood as an increase in tunneling probability due to hopping via molecular orbitals. We find the effect is substantially larger for O 2 than for N 2 , and for semiconducting rather than metallic SWNTs junctions, in agreement with experiment.

Effect of nitrogen doping and hydrogen confinement on the electronic properties of a single walled carbon nanotube

“…As the concentration of nitrogen atoms is increased to 2 atoms, we noticed a sharp splitting of the band and the impurity state of nitrogen contributes mainly to the conduction band minimum. The valance and the conduction bands cross each other at the Fermi level, which is in agreement with previous results [14][15][16]. Energy band splitting engineering techniques have played a vital role in tuning the band gap of CNTs.…”

A Flexible Multifunctional Sensor Based on Carbon Nanotube/Polyurethane Composite

“…The adsorption of vapor molecules causes increase in the resistance and desorption of vapor molecules causes decrease of macroscopic resistance when non-conductive layers between the tubes is desorbed [19,20]. The curves in Fig.…”

Optical properties of armchair (7, 7) single walled carbon nanotubes

“…The optical properties of SWCNTs have been simulated in various studies. [6][7][8] Although several experimental [9][10][11][12][13][14][15][16][17][18][19][20][21] and theoretical studies [22][23][24][25][26] have considered (7, 7) the carbon nanotubes properties, the optical spectrum of CNTs (7,7) has not been probed yet.…”