Hydrogen and hydrocarbon gas sensing performance of Pt/WO3/SiC MROSiC devices

Pt/WO3/SiC devices based Schottky diodes have been fabricated and their hydrogen and hydrocarbon gas sensing performance investigated. The semiconducting metal oxide WO3 films were 100 nm thick and prepared using r.f. magnetron sputtering. A Pt layer was deposited on the top of the WO3 forming the Schottky diode. The I-V characteristics have been analyzed, from which the change in the barrier height, subject to the introduction of the analyte gas, was calculated. The dynamic properties of these sensors were evaluated at constant biasing currents of 9 and 90 mu A, at temperatures between 300 and 700 degrees C. The results show the sensors have extremely stable baseline, with all responses being repeatable. Voltages shifts in excess of 1V were observed.