THICK-FILM HYDROGEN SENSOR

A thick-film SnO2-based hydrogen gas sensor has been developed. The fabricated device is found to be very sensitive for hydrogen gas and is capable of detecting hydrogen in the order of a few ppm (less than or equal to 100) concentration. The effects of temperature and the amount of catalytic palladium doping in SnO2 towards the hydrogen sensitivity of the sensor have been studied. The peak sensitivity of the sensor towards hydrogen is found to be at an operating temperature of 350 degrees C and the optimum catalytic content in the SnO2 layer is 0.25 wt.% palladium. A possible reaction scheme for the interaction of hydrogen with the SnO2 surface in air is also proposed.