Sensing properties to dilute chlorine gas of indium oxide based thin film sensors prepared by electron beam evaporation

Indium oxide based thin film sensors have been prepared by means of an electron beam evaporation and subjected to the detection of dilute Cl2 gas less than ppm-level. Among various In2O3 based sensors tested, the In2O3 thin film modified with Fe2O3 (1 wt.%) showed extremely high sensitivity to dilute Cl2 gas of 0.2–5 ppm. The Fe2O3–In2O3 sensor showed the sensitivity as high as 4.5 to 0.2 ppm Cl2 in air. From the results of response transients and AFM, it is assumed that the addition of Fe2O3 stabilizes the lattice oxygen in In2O3 and increases in number of adsorption site of Cl2.