Sensitivity to NH3 of SnO2 thin films prepared by magnetron sputtering

Abstract

SnO2 thin film sensor was fabricated with microelectronic technology and NH3 (ammonia) gas sensing characteristics were measured in a temperature range 200–375 °C. It was observed that surface doping with platinum improves significantly the material's sensitivity to ammonia, and the optimal operational temperature of the sensor was 325 °C. The sensor showed high sensitivity to low NH3 concentration in the range 20–350 ppm with relatively fast response (10 s) and recovery times (30 s), respectively.