Pure and Cupricated BaSnO₃ thick film resistor: Synthesis, Characterization and studies on its gas sensing performance

In this work we report the synthesis, microstructure, electric properties and sensing performance of BaSnO₃ (BS) powder, it was prepared by mechano-chemical method. As prepared powder is calcinated at temperatures 1100 °c, and 1300 °c tested for crystallization. Thick films were prepared using simple screen-printing technology. Structural and electrical analyses were performed and the results have been correlated. The material was tested for various gases such as CO, CO_2, NH₃, Cl₂, H₂, LPG, ethanol, and H₂S. The pure BS film shows good response multiple gases at various operating temperature up to 500⁰C as NH₃, CO₂, CO, ethanol and, H₂S for different gas concentrations, when the pure film is surface modified with aqueous solution of Cucl₂ using simple dipping technique for various time intervals (5 min., 10 min., 20 min. and, 30 min.), film improves the selectivity and sensitivity. Maximum response (S=36.2) was found to H₂S gas at temperature of 250 ⁰C and S=12.1 for ethanol at 500 °c for gas concentration of 50 ppm with film dipped for 10 min. time interval. The characterization of the films was done by XRD, SEM and TG-DTA. Crystallite size, texture coefficient, specific surface area, electric properties and gas sensitivity of the films were measured and presented.