Fast-response ozone sensor with ZnO nanorods grown by chemical vapor deposition

Nanostructures of ZnO grown by chemical vapor deposition were used as sensing materials. These materials, ZnO nanorods, were characterized by scanning electron microscopy (SEM), photoluminescence (PL) and X-ray diffraction (XRD). The ozone sensing properties of various ZnO nanomaterials were studied. Under 2.5 ppm ozone, ZnO nanorods showed a rapid response time of 45 s and recovery time of 5 s, and the sensor response (S, the ratio of the resistance in an ozone gas without UV to resistance in air with UV, S = Rozone/Rair) is 850. The low defect density and high mobility accounts for the fast response and recovery times. The sensor response was measured in the range from 1 to 2.5 ppm ozone in this study.