Modifying the selectivity and gas sensitivity of resistive adsorption sensors by targeted doping

This paper explores the physical and chemical laws of energy variations in adsorption centers and the influence exerted on gas-sensitive properties by the targeted doping of semiconductor resistive sensors. The authors establish that minimization of the degradation processes in multisensors requires making each element of these sensors from a same material. In doping by modifiers, an important role belongs to many factors, particularly, the ratio of the squared charge of an impurity ion and its radius. As this factor takes smaller values than that of the parent-ray material, the number of Bronsted centers on the surface goes down and the influence of Lewis centers grows accordingly. The major impact on the energy of surface centers is introduced by the defect rate of the crystal structure (the degree of deviation from stoichiometry).