Detecting CH4 and CO Gases Using Micro-Structural Doping Compound Oxide Films on Si-Substrates
Y.F. Li, S.Y. Ma, L.B. Kish, J.-J. Ding
Northwest Normal University, US
Keywords: sensor, chemical, gas, film
Abstract:Fluctuation-enhanced chemical sensing with commercial gas sensors have already been studied[1-4]. Fig. 1 shows one of the typical fluctuation-enhanced signals of PdxWO3 film sensor. The gas-sensing films used in commercial gas sensors are deposited on insulating Al2O3 –substrate. In order to improve the gas sensing properties such as the selectivity to CH4 and CO, long-term thermal stability, low power consumption, and consistency, the micro-structural doping compound oxide gas sensing films (WO3/SnO2, TiO2/SnO2, MoO3/SnO2, In2O3/SnO2) on Si-substrates have been deposited by using the several-target alternation radio frequency magnetron sputtering technique or co-sputtering technique with composite target and annealed at high temperature. In this paper, the effect of gas sensing film characteristics on gas sensing properties will be presented. A large effort is devoted to explore reactive mechanism between Si-based microstructure doping compound oxide gas sensing material and CH4/CO based on the study of microstructure, chemical composition of gas sensing material ion store layer and ion conduction layer and interface condition between them. Our accomplishment is that the compound oxide gas-sensing films presented in this paper are deposited on Si-substrate. They have high selectivity to CH4/CO, obvious fingerprint spectrum in fluctuation-enhanced chemical sensing measurement and good stability at high temperature.