Gas-sensing properties of doped In2O3 films as sensors for NO2 in air

摘要: A number of sensing systems based on indium oxide doped with various metal oxides (In2O3 · WO3, In2O3 ZnO, RuO2, Gd2O3, and Sm2O3) in amounts no more than 3–5 mol % also Au films were studied as sensors for detecting NO2 air. The working temperature was 250°C (except which T = 150–190°C). WO3-based reach a high sensitivity especially at concentration air higher 10 ppm (the relative sensor conductivity changes by 2.5 orders magnitude). However, shortcoming this system is an increased response time (7–9 min) compared to the other systems, does not exceed 15–20 s. Gd2O3 Sm2O3 exhibit best properties sensitivity, selectivity, stability. Various species adsorbed surface dispersed detected Fourier-transform IR spectroscopy. mechanism changing upon discussed.