Pt:SnO2 thin films for gas sensor characterized by atomic force microscopy and x‐ray photoemission spectromicroscopy

SnO2 thin films have been grown by radio frequency reactive sputtering method in order to be used as a gas sensor. Subsequently Pt has been added to the SnO2 films to increase the sensitivity to carbon monoxide gas. Two different substrates have been used: rough and mechanically polished alumina. The morphology of the film has been characterized by atomic force microscopy, whereas the chemical composition was analyzed by x‐ray photoemission spectromicroscopy. Pt:SnO2 clusters with widths of 500–600 nm were observed on the rough alumina, whereas on the mechanically polished alumina, the Pt:SnO2 film was smoother. X‐ray photoemission spectromicroscopy measurements show for Pt:SnO2 films on rough alumina substrates different charging in different areas of the sample. The response curve to carbon monoxide is 30% higher for rough alumina.