Optimization of a NOx gas sensor based on single walled carbon nanotubes

In the present work it is shown an efficient method for NOx detection in single wall carbon nanotubes (SWCNT) ordered by mean of dielectrophoretical process after dispersion in clorophormium solution over gold interdigitates. The NOx flux induces resistance change with respect of pure N2 flux over the ordered SWCNT. We investigate the efficiency of NOx detection when a control signal is applied to the sensing device through a back side contact, for optimized response time of the sensor. Moreover we studied the effect on absorption/desorption gas processes for NOx and NH3 by applying a gate voltage to the Si substrate beneath the interdigitated electrodes. The results indicate an improvement of the time and that acceleration of the response time of the sensor for the detection of NH3 is proportional to the gate voltage in the range 0–40 V.