Selectivity and sensitivity studies on plasma treated thick film tin oxidegas sensors

This paper deals with selectivity and sensitivity studies on plasma treated tin oxide thick film gas sensors. Response of oxygen, hydrogen, nitrogen a nd argon plasma treated sensors has been studied upon exposure to CCl4, C3H 7OH, CO, LPG, N2O and CH4. It is observed that the sensitivity of sensors t reated in various gaseous plasma is much higher at room temperature in comp arison to untreated sensors. The selectivity of these sensors also improves upon plasma treatment, specifically, hydrogen plasma treated sensor become s sensitive to CO. Also, the XRD characterization of SnO2 has been carried out with respect to various plasma treatments. The structural changes obtai ned on plasma treatment have been analysed in terms of stoichiometric varia tions in tin oxide using the ionic conduction model and a thus better expla nation for sensitivity of plasma treated sensors have been provided. (C) 20 00 Elsevier Science Ltd. All rights reserved.