Sensing characteristics of zinc oxide thin films deposited by spray pyrolysis onto tubular Pyrex substrate

This paper presents NO2 sensing properties of ZnO thin films grown onto tubular Pyrex substrate using the spray pyrolysis method. The sensor response was found to depend essentially on four parameters: chemical composition, structure, morphology and operating temperature. The crystallinity and morphology of the as-preapred films were analyzed using X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). The sensing properties of ZnO toward NO2 were investigated at different operating temperatures and NO2 concentrations. Optimization of the preparation conditions show that ZnO thin film deposited during 15 min exhibit the highest sensitivity with fast response and recovery time.