Nanocrystalline Cobalt-doped SnO2 Thin Film: A Sensitive Cigarette Smoke Sensor

This article discusses a sensitive cigarette smoke sensor based on Cobalt doped Tin oxide (Co-SnO2) thin films deposited on glass substrate by a conventional Spray Pyrolysis technique. The Co-SnO2 thin films have been characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDAX). The XRD spectrum shows polycrystalline nature of the film with a mixed phase comprising of SnO2 and Co3O4. The SEM image depicts uniform granular morphology covering total substrate surface. The compositional analysis derived using EDAX confirmed presence of Co in addition to Sn and O in the film. Cigarette smoke sensing characteristics of the Co-SnO2 thin film have been studied under atmospheric condition at different temperatures and smoke concentration levels. The sensing parameters such as sensitivity, response time and recovery time are observed to be temperature dependent, exhibiting better results at 330 oC.