The electrical response to O-3 of 150-nm-thick carbon nanotube (CNT) thin films prepared by radio frequency-plasma enhanced chemical vapor deposition has been investigated at different operating temperatures starting from the room temperature. The interaction between ozone molecules and a carbon nanotube film is studied by means of first-principles calculations. Experiments show that CNT films are responsive to O-3 with a decrease of the resistance similar to that observed for NO2 Our theoretical results suggest the interaction to be pretty strong, as shown by a relatively short equilibrium molecule-tube distance, as well as by an appreciable binding energy and charge transfer from the tube to the adsorbed molecule. The analysis of the density of states shows that a peak in proximity of the nanotube Fermi level is induced by the ozone adsorption. This effect enhances the p-type character of the nanotube and, therefore, the conductivity of the whole film increases, in excellent consistency with the experimentally observed resistance decrease upon O-3 exposure.

Ozone adsorption on carbon nanotubes: Ab initio calculations and experiments

ARMENTANO, ILARIA;KENNY, Jose Maria;VALENTINI, LUCA;
2004

Abstract

The electrical response to O-3 of 150-nm-thick carbon nanotube (CNT) thin films prepared by radio frequency-plasma enhanced chemical vapor deposition has been investigated at different operating temperatures starting from the room temperature. The interaction between ozone molecules and a carbon nanotube film is studied by means of first-principles calculations. Experiments show that CNT films are responsive to O-3 with a decrease of the resistance similar to that observed for NO2 Our theoretical results suggest the interaction to be pretty strong, as shown by a relatively short equilibrium molecule-tube distance, as well as by an appreciable binding energy and charge transfer from the tube to the adsorbed molecule. The analysis of the density of states shows that a peak in proximity of the nanotube Fermi level is induced by the ozone adsorption. This effect enhances the p-type character of the nanotube and, therefore, the conductivity of the whole film increases, in excellent consistency with the experimentally observed resistance decrease upon O-3 exposure.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/162115
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 45
social impact