| Nanostructured InOx and ZnOx films and their sensing properties are presented with respect of their surface texture and composition. They were prepared by reactive dc magnetron sputtering in a mixture of argon-oxygen plasma using metallic In and Zn targets onto Corning glass and Si substrates at room temperature. The structure of the films, i.e., the crystallinity and the microstructure, was investigated by X-ray diffraction analysis and Atomic Force Microscopy (AFM). The nanostructure of their surfaces is highly controlled by the deposition parameters and the subsequent in-plain grain size and surface roughness, which, in term, control the transport properties, and thus the sensing characteristics of these films as measured by a conductometric technique. Based on conductivity changes of up to seven orders of magnitude and under selected deposition and film structure conditions their sensitivity was highly improved and pushed to bellow 10 ppb for O3 and bellow 80 ppb for NO2. |
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