A carbon monoxide interdigitated-capacitor gas sensor based upon a n-type Zn2SnO4 thin film

The microstructures of Zn2SnO4 thin films were examined with a view to their exploitation for gas sensor. Zn2SnO4 thin films were prepared using the radio frequency magnetron sputtering with various annealing temperatures. Zn2SnO4 thin films were analyzed by X-ray diffraction and microstructural observations. The Zn2SnO4 thin films that were annealed at 700 and 900 degrees C contained second phase of ZnSnO3 and SnO2, respectively. The cross-sectional SEM image of a Zn2SnO4 thin film that were annealed at 700 degrees C showed a dense film lacking voids throughout the bulk. A carbon monoxide interdigitated-capacitor gas sensor, based on a n-type Zn2SnO4 thin film was realized. The capacitance of the sensor device increases linearly with concentration of carbon monoxide.