Employment of Titanium dioxide thin film on NO2 gas sensing

Abstract

TiO2 thin films were deposited by Spray Pyrolysis with thickness ((350±25) nm) onto glass substrates at (350°C), and the film was annealed at temperatures (400 and 500)°C. The structural and morphological properties of the thin films (TiO2) were investigated by X-ray diffraction, Field emission scanning electron microscopy and atomic force microscope. The gas sensor fabricated by evaporating aluminum electrodes using the annealed TiO2 thin films as an active material. The sensitivity of the sensors was determined by change the electrical resistance towards NO2 at different working temperatures (200 and 300)°C. It was determined that the fabricated sensor using TiO2 thin film annealed at (400)°C with 8.28 nm particle size has high sensitivity than the thin films annealed at 500°C with 10.37 nm particle size. The sensor operated at 200°C had also sensitive to the NO2 gas and its sensivity increased with operated temperatures at 300°C. It was observed that the fabricated sensors exhibited reproducible and stable results.