This contribution deals with Carbon Nanotubes Field Effect transistors (CNTFETs) based gas sensors fabricated using a completely new dynamic air-brush technique for SWCNTs deposition. More precisely, we have developed a machine which allows us the dynamic deposition on heated substrates of SWCNT solutions, improving dramatically the uniformity of the SWCNTs mats. The fabricated CNTFETs have been developed for gas sensing applications. Indeed we have fabricated arrays of CNTFETs achieved using different metal electrodes (patented approach) to exploit the change of metal/SWCNTs junction characteristics as a function of the gas detected in order to identify a sort of electronic fingerprinting. This phenomenon is related to the change of the metal work function and so of the Schottky barrier and seems to be extremely selective. The results obtained in this contribution, concerning the sensitivity of all the transistors on the same chip (200ppb for NO2, 1ppm for NH3 and around 1ppm for DMMP), are at the state-of-the-art considering that we have not functionalized chemically or biologically our devices and that we have tested CNTFETs fabricated using CNT mats as channels for the transistors at ambient conditions.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2012: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: June 18, 2012
Pages: 228 - 231
Industry sector: Advanced Materials & Manufacturing
Topics: Carbon Nano Structures & Devices