Coated and functionalised single-walled carbon nanotubes SWCNTs as gas sensors

Coated and functionalised single-walled carbon nanotubes (SWCNTs) as gas sensors 

BATTIE, Universite de Lorraine, France and O. DUCLOUX, ONERA, France 

Abstract This chapter focuses on the performances of gas sensors based on single-walled carbon nanotubes (SWCNTs).The chapter first reviews chemiresistor and field-effect transistor sensor architectures. Theoretical models based on doping effect and Schottky barrier modulation are correlated to the percolation of metallic carbon nanotubes. The functionalisation strategies of carbon nanotubes, used to acquire a gas selectivity, are discussed and offer promising application for the monitoring of air quality, or military and medical applications. 

Key words single-walled carbon nanotnbes, Schottky barrier, doping, functionalisation, gas selectivity. 

The commonly accepted physico-chemical gas sensing mechanisms of SWCNT-based gas sensors are discussed in detail by several authors (Bradley 2003 Pengetfli,2009 Battie eta/.,2012b).These mechanisms,which will be described in Section 10.3, are the charge transfer between adsorbed gas molecules and SWCNTs, and the modulation of the Schottky barrier established between semiconducting SWCNTs and metallic electrodes. 

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