Low concentration CO gas sensing properties of hybrid ZnO architecture

•ZnO film/nanowire architecture was grown by sputtering and CVD techniques.•CO gas sensing properties were studied in 10–50 ppm concentration range.•Higher surface-to-volume resulted in improved sensitivity at 400 °C and faster response.•Non-linear increase in sensitivity due to interconnection points and chemisorption processes

ZnO thin film and nanowire morphologies were employed to fabricate CO gas sensors by using radio frequency magnetron sputtering and chemical vapour deposition growth. The sensing properties were measured at CO gas concentration ranging from 10 to 50 ppm at varying operating temperature. The results showed a 5-folded sensitivity and half-reduced response time for the hybrid material based on both thin film and nanowires with respect to thin film only, thus indicating the high potential of morphology tailoring, namely, the surface-to-volume ratio and depletion layer, for the enhancement of ZnO sensing performance.

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