Study of the Sensitivity of Porous SnO2-Based Thick-Film Elements to the Hydrogen Concentration in Air

Semiconductor gas sensors based on metal oxides are sensitive and fast with low power consumption. The specific features of the manufacturing technology of such transducers make it possible to reduce their overall dimensions and, thus, open up considerable opportunity for integrating them into portable devices. In the production of semiconductor gas sensors, an important stage is the formation of a metal-oxide sensitive layer, and specifically, the process of combining a highly porous metal-oxide layer with integrated structures. In this paper, the results of studies of the experimental samples of gas-composition transducers with a porous gas-sensitive layer are reported. The gas-sensitive layer is formed by inkjet microprinting of a SnO2-based suspension with subsequent annealing. The sensitivities of the experimental samples of gas-composition transducers with gas-sensitive layers formed from two types of the initial suspension, and specifically, from a suspension based on pure SnO2 and on SnO2 doped with Cr and Nb, are compared. The dependence of variations in the conductivity of an experimental sample of the integrated gas-composition transducer on the H2 concentration in air is obtained. It is established that the gas-sensitive layer based on SnO2 with Cr and Nb additives exhibits a higher sensitivity to variations in the gas concentration to be detected, which is due to the larger specific surface area and less efficient agglomeration of particles.