Study of Characteristics of the Sensor Detecting of Low Concentration of Ammonia

Abstract

In this work, the morphology of Fe₂O₃:ZnO (60 : 40 mol %) film and gas sensing characteristics to ammonia vapors at different operating temperatures were investigated. The SEM investigation of the surface of the sensitive film of Fe₂O₃:ZnO showed that the grain size in the film was about 50 nm. The sensor showed sensitivity to ammonia vapors starting at 200°C and the operating temperature was chosen as 250°C. The low detection limit of the sensor based on Fe₂O₃:ZnO is quite low (~14 ppm) and at this concentration of ammonia vapors the resistance of the sensor changed more than 1.5 times. The enhanced parameters of the Fe₂O₃:ZnO-based sensor will allow using this structure in ammonia detecting devices.