MECHANISM OF TRACE LEVEL H2S GAS SENSING USING RF SPUTTERED SnO2 THIN FILMS WITH CuO CATALYTIC OVERLAYER
نویسندگان
چکیده
H2S gas sensing response characteristics of bare SnO2 thin films and heterostuctures with nanolayer (10 nm) of Cu and CuO are studied. Changes in resistance values, occurring with integration of Cu and CuO nanolayers on SnO2 is acquired real-time, and compared. Rise in sensor resistance after introduction of Cu and CuO nanolayers on SnO2 sensing layer is understood to enhance the sensing response characteristics. Formation of space charge region between p-type CuO and n-type SnO2 and difference in work-function values between catalyst and sensing layer are shown to govern the increased value of starting resistance. Increase in starting resistance and lowering of resistance in presence of H2S due to spill-over of dissociated H2S gas molecule are playing crucial role in influencing the sensing response.
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