NH3 sensing characteristics of pure and Al modified WO3 thin films

摘要

Ammonia sensing properties of pure and Al modified WO3 thin films prepared using RF sputtering have been investigated. Both the sensor films exhibited a maximum response at an operating temperature of 250°C. Modification with Al has been demonstrated to improve the response kinetics in particular the response time (6 min) in comparison to that of pure WO3 (8 min) towards NH3 (100 ppm). Interestingly, both the sensor films showed an increase in resistance i.e., a p-type behavior upon exposure to NH3.