Dependences of Characteristics of Sensors Based on Tin Dioxide on the Hydrogen Concentration and Humidity of Gas Mixture

An expression is obtained for the energy band bending e phi(sH) on the surface of the SnO2 film in the clean air + hydrogen mixture. It is assumed that the value of e phi(sH) depends not only on the surface charge density of adsorbed oxygen ions O-A<overline>, but also on the negative charged hydroxyl groups (OHA<overline>). The results of the analysis of the dependences of e phi(sH) on the hydrogen concentration and the absolute humidity of the gas mixture obtained during the operation of the sensor in the thermo-cyclic mode are presented. A method for the determining in the examined gas mixture is proposed. The method based on the dependence of e phi(sH) on the hydrogen concentration established during the calibration of the sensor is proposed. The dependences of the energy band bending on the SnO2 surface at = 0 and the conductivity of the sensor on its temperature during the heating period are discussed.