The Impact of the Nature of the Electrode Material on SnO2 Thick Film Sensor Performance: Influence on Oxygen Adsorption

Abstract

SnO2 thick film sensors on Al2O3 substrates with two different electrode materials, i.e., gold and platinum, were investigated concerning their sensing properties towards CO and H2 in dry air. Electrical measurements differ significantly in response behavior based on the nature of the electrode. By varying only the oxygen concentrations and measuring the change in resistance, a strong dependence of the interaction of oxygen is detected whether gold or platinum electrodes were used. These observations lead to the conclusion that temperature-dependent oxygen adsorption processes, as well as a direct catalytic conversion of the test gas, catalyzed by the electrode material strongly influence sensor performance characteristics.