UV-Enhanced Ethanol Sensing Properties of RF Magnetron-Sputtered ZnO Film.

ZnO film was deposited by the magnetron sputtering method. The thickness of ZnO film is approximately 2 mu m. The influence of UV light illumination on C2H5OH sensing properties of ZnO film was investigated. Gas sensing results revealed that the UV-illuminated ZnO film displays excellent C2H5OH characteristics in terms of high sensitivity, excellent selectivity, rapid response/recovery, and low detection limit down to 0.1 ppm. The excellent sensing performance of the sensor with UV activation could be attributed to the photocatalytic oxidation of ethanol on the surface of the ZnO film, the planar film structure with high utilizing efficiency of UV light, high electron mobility, and a good surface/volume ratio of of ZnO film with a relatively rough and porous surface.