Inkjet printed resistive and chemical-FET carbon nanotube gas sensors

Aqueous solutions of carboxyl functionalized single-wall carbon nanotube (SWCNT) films are deposited on silicon chips by the inkjet printing technique. By varying the film thickness it is possible to obtain low- or high density networks of SWCNTs, having either nonlinear or linear current-voltage characteristics, respectively. The electrical transport in the low-density films is gate-controllable and utilized as chemical field-effect transistor sensors; whereas the high-density SWCNT networks of nearly Ohmic behaviour are used as conventional resistive gas sensors. The response of both types of sensors is studied for hydrogen sulfide (H2S) analyte. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim