H2S gas sensor based on SnO2 (40 nm)/ NiO (20 nm) thin film was fabricated by DC sputtering method in combination with photolithography technique. Morphology, crystal structure, and composition of the synthesized thin film were characterized by SEM, EDS and XRD. The gas-sensing characteristics of the fabricated sensor were studied by real time measurement of resistance change in air and different concentrations of H2S gas. Results show that the sensor can measure low concentrations of H2S (2,5 to 10 ppm) at various temperatures ranging from 250 to 400 oC with fast response time (about 13 - 33 seconds) and fulfill the requirements in air monitoring.
