Modification of sensitivity of BaSnO3 sensor due to parameters of synthesis and formation of the device

Y. OCHOA; F. SCHIPANI; C.M. ALDAO; J.E. RODRÍGUEZPÁEZ; M.A. PONCE

JOURNAL OF MATERIALS RESEARCH

MATERIALS RESEARCH SOC

Año: 2015 vol. 30 p. 3423 - 3430

0884-2914

Powders of BaSnO3 were synthesized to obtain gas sensor thick films (using the screen printingtechnique) for the detection of O2 and CO. Impedance spectroscopy was used at differentatmospheres and temperatures. In the presence of O2, the films showed a maximum value ofsensitivity at 300 °C, with the powders formed by Pechini presenting greater reproducibility andsensitivity (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 presenteda better response to CO, with a maximum sensitivity at 450 °C. In addition, in the presence of COand for T . 250 °C, these films showed an anomalous behavior regarding their sensitivity asa function of time when platinum electrodes were used: a great increase in the electrical resistancevalue for exposure times greater than 10 min.