Improvement in sensitivity and recovery of single-walled carbon naootube-based gas sensors

摘要

This paper presents an improvement in sensitivity and recovery of the single-walled carbon nanotube (SWNT)-based gas sensors. The sensors were fabricated from SWNT powder by a screen-printing method, followed by annealing for 2 h in open-air at various temperatures. From Raman spectra of the SWNT bundles and the response to ammonia (NH3) exposure of the sensors, it turned out that annealing at a relevant temperature could improve the sensor sensitivity. A combination of evacuating and flowing carrier gas significantly improved the sensor recovery. At the optimized operating condition, the sensor resistance retrieved its initial value after only 25 min degassing.