Abstract
In our previous study, we reported the successful preparation of highly CO selective ZnO/SnO2 thin film with hetero-layered structure. In this study, we report the microstructure and gas sensing properties of ZnO/SnO2 composite thin film. Columnar structure obtained in the hetero-layered ZnO/SnO2 thin film was not observed in the ZnO/SnO2 composite thin film. The sensitivity for CO gas of ZnO/SnO2 composite thin film was improved above 200 as ZnO content increased to 50mol% at 400C. In addition, the CO sensitivity also increased with operating temperature decreased, and maximum sensitivity was 587 at 200C. These results were different from hetero-layered ZnO/SnO thin film, indicating that the CO sensing properties of the ZnO/SnO2 thin film were influenced by the microstructure. In the presentation, the influences of H2 gas for the CO sensitivity of the ZnO/SnO2 thin film will be presented.
