High Sensitivity Semiconductor NO_2 Gas Sensor Based on Mesoporous WO_3 Thin Film

摘要

A NO_2 gas sensor based on mesoporous WO_3 thin film with low operating temperatures and its sensing characteristics are reported. The mesoporous WO_3 thin film exhibits regular pores with an average pore size of 5 nm and specific surface area of 151 m~2/g. Excellent sensing properties are found upon exposure to 3 ppm of NO_2 at 35-100 deg C for mesoporous WO_3 thin film. The sensor response is 180 for 3 ppm NO_2 at 100 deg C. The ability to sense NO_2 at such low temperatures is attributed to the large surface area (151 m~2/g) that offers many active sites for reaction with NO_2 molecules.