نویسندگان
دانشکدهی مهندسی برق، دانشگاه صنعتی خواجه مصیرالدین طوسی
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
SnO 2 based thin film resistive gas sensors were assessed by the measurement of their sensitivities to various combustible
gases. The gas sensitive thin films were deposited on cold silica substrates in vacuum by electron beam evaporation. The XRD analysis revealed the films to be amorphous. The crystallization of the films was carried out by annealing at 300 for 140 min.The average particle size of the annealed layers was estimated to be 13 nm. The sample gas sensors were then fabricated by providing two ohmic contacts and the attachment of an electric micro-heater. The sensitivities of the sample resistive gas sensors to methanol, ethanol, propanol and butanol were measured at different concentrations.It was observed that, at low concentration levels, the sensitivity of the sensors increases with the molar mass of the target gas,i.e. at a constant concentration, the sensitivity to methanol was the lowest while that of butanol was the highest. It was also observed, for the first time, that the sensitivity saturation for the gases examined occurs at, approximately, a constant weight-concentration, regardless of the molecular weight of the target gas. A model is suggested for the gas-solid interaction mechanism, which describes the results
کلیدواژهها [English]
)