Fabrication and characterization of ZnO thin film for hydrogen gas sensing prepared by RF-magnetron sputtering

A ZnO thin film-based gas sensor was fabricated using a SiO2/Si substrate with an integrated platinum comb-like electrode and heating element. The structural characteristics, morphology, and surface roughness of the as-grown ZnO nanostructure were investigated. The optical properties were examined by UV-vis spectrophotometry. The film revealed the presence of a c-axis oriented (002) phase of 20.8 nm grain size. The sensor response was tested for hydrogen concentrations of 50, 70, 100, 200, 400, and 500 ppm at operating temperatures ranging from 250 degrees C to 400 degrees C. The sensitivity toward 50 and 200 ppm of hydrogen at the optimum operating temperature of 350 degrees C were about 78% and 98%, respectively. The response was linear within the range of 50-200 ppm of hydrogen concentration. Our results demonstrated the potential application of ZnO nanostructure for fabricating cost-effective and high-performance gas sensors. (c) 2013 Elsevier Ltd. All rights reserved.