Gas identification by quantitative analysis of conductivity-vs-concentration dependence for SnO2 sensors

Dependence of the conductivity of a thin-film gas sensor on the concentration of the ethanol or acetone vapors in air has been studied. We found that power law describes this dependence only in a part of the whole vapor concentration range. Theoretical model of the gas response of thin-film gas sensor has been proposed. The basic model parameters, such as desorption heat of the gas particles from the sensor surface or the separation between the energy levels induced by the gas species and levels induced by the oxygen particles in the energy gap of the sensor film material, can be used as identifying agents. The identification ability of a single-gas sensor based on SnO2 thin film is demonstrated by processing the concentration dependence of the sensor conductivity.