Temperature variation of the current-voltage characteristics of thin-film gas sensors

Variation of the current-voltage (I-U) characteristics of thin-film gas sensors based on tin dioxide (SnO2) in the presence of various gases has been studied in a range of working temperatures from 200 to 450°C. The experimental I-U curves are interpreted assuming that various forms of adsorbed oxygen species are present on the tin dioxide surface and that the adsorbed ions can migrate over the surface with different mobilities. Features of the observed phenomena can be used for selecting working temperatures at which an analysis of the I-U curves can provide a basis for the identification of various species adsorbed on the same sensor.