title: Thickness dependent sensing mechanism in sorted semi-conducting single walled nanotube based sensors.
abstract: Single walled carbon nanotube (SWCNT) networks present outstanding potential for the development of SWCNT-based gas sensors. Due to the complexity of the transport properties of this material, the physical mechanisms at stake during exposure to gas are still under debate. Previously suggested mechanisms are charge transfer between gas molecules and SWCNT and Schottky barrier modulation. By comparing electrical measurements with an analytical model based on Schottky barrier modulation, we demonstrate that one mechanism or the other is predominant depending on the percolation of metallic carbon nanotubes. Below the metallic SWCNT percolation threshold, sensing is dominated by the modulation of the Schottky barrier, while above this threshold, it is only attributed to a charge transfer between SWCNT and gas molecules. Both mechanisms are discussed in terms of sensitivity and resolution leading to routes for the optimization of a gas sensor architecture based on highly enriched semiconducting carbon nanotube films.
authors.affiliation: LEM ONERA-CNRS UMR 104, 29 Av. de la Division Leclerc, 92322 Châtillon, France. annick.loiseau@onera.fr
authors.forename: Yann
authors.initials: Y
authors.lastname: Battie
authors.forename: Louis
authors.initials: L
authors.lastname: Gorintin
authors.forename: Olivier
authors.initials: O
authors.lastname: Ducloux
authors.forename: Philippe
authors.initials: P
authors.lastname: Thobois
authors.forename: Paolo
authors.initials: P
authors.lastname: Bondavalli
authors.forename: Gilles
authors.initials: G
authors.lastname: Feugnet
authors.forename: Annick
authors.initials: A
authors.lastname: Loiseau