Modification of sensitivity of BaSnO sub(3) sensor due to parameters of synthesis and formation of the device

• Published in: Journal of materials research Vol. 30; no. 22; pp. 3423 - 3430
• Main Authors: Ochoa, Yasser H, Schipani, Federico, Aldao, Celso M, Rodriguez-Paez, Jorge E, Ponce, Miguel A
• Format: Journal Article
• Language: English
• Published: 27.11.2015
• Subjects: Barium stannate; Cobalt; Electrical resistance; Electrodes; Gas sensors; Reproducibility; Synthesis; Thick films
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2015.318

Powders of BaSnO sub(3) were synthesized to obtain gas sensor thick films (using the screen printing technique) for the detection of O sub(2) and CO. Impedance spectroscopy was used at different atmospheres and temperatures. In the presence of O sub(2), the films showed a maximum value of sensitivity at 300 degree C, with the powders formed by Pechini presenting greater reproducibility and sensitivity (with an order of magnitude greater than that for the powders formed by precipitation). Results showed that the films formed with powders obtained using the Pechini method presented a better response to CO, with a maximum sensitivity at 450 degree C. In addition, in the presence of CO and for T > 250 degree C, these films showed an anomalous behavior regarding their sensitivity as a function of time when platinum electrodes were used: a great increase in the electrical resistance value for exposure times greater than 10 min.