Titanium Dioxide Thin Films as Methane Gas Sensors

TiO2 thin film was deposited onto n-Si substrate at 100 degrees C by using a sputteringmethod, and the film was annealed in air atmosphere at range of 500 degrees C-1000 degrees C. The structural and morphological properties of the all films were investigated by X-ray diffraction and atomic force microscope. The gas sensor with interdigitated platinum electrodes was fabricated with photolithographic techniques using the as-deposited and annealed TiO2 thin films as an active material. The sensitivity of the sensors was determined by altering the conductivity of the sensor material under methane gas with various concentrations at different working temperatures. It was determined that the fabricated sensor using as-deposited TiO2 thin film with 10-nm particle size has high sensitivity and fast response/recovery time. The sensor operated at 50 degrees C had also sensitive to the methane gas and its detection performance increased with temperatures. It was observed that the fabricated sensors exhibited reproducible and stable results.