Highly selective CNTFET based sensors using metal diversification methods

This contribution deals with Carbon Nanotubes Field Effect transistors (CNTFETs) based gas sensors fabricated using a new dynamic spray based technique for SWCNTs deposition. This technique is compatible with large surfaces, flexible substrates and allows to fabricate high performances transistors exploiting the percolation effect of the SWCNTs networks achieved with extremely reproducible characteristics. Recently, we have been able to achieve extremely selective measurement of NO2 , NH3 and DMMP using four CNTFETS fabricated using different metals as electrodes (Pt, Au, Ti, Pd), exploiting the specific interaction between gas and metal/SWCNT junction. In this way we have identify a sort of electronic fingerprinting of the gas. The time response is evaluated at less than 30sec and the sensitivity can reach 20ppb for NO2, 100ppb for NH3 and 1ppm for DMMP (Di-Methyl-Methyl-Phosphonate).