ZnO based materials have been have been extensively investigated during the last years due to their application in different fields such as optoelectronics, photocatalysis or gas sensing. The potential use of ZnO as sensor material is increased by using compacted powder material and nano- and microstructures, with a high surface-to-volume ratio.
In this work, ZnO sensing properties have been measured by monitoring both electrical resistivity and luminescent emission in the presence of several gases as ethanol vapour or CO. The correlation between both measurements will let us to gain a deeper knowledge on the influence of several material characteristics, as defect structure, morphology, on the sensing properties and hence a better knowledge of the mechanisms behind sensing. On the other hand the determination of the relationship between changes in resistivity and luminescence emission in different environmental conditions, will provide a valuable tool to design sensor devices for different applications. In particular luminescence could open the additional possibility to selective sensing since the presence of different gases would affect to different emission bands, hence rendering a selective response to the environment composition.