Structural, optical and ethanol gas-sensing properties of zinc oxide thin film prepared by spray pyrolysis technique using ultrasonic nebuliser

Zinc oxide thin films were prepared on glass substrate at the optimum temperature of (300±10)°C by spray pyrolysis technique using ultrasonic nebulizer. Films thus prepared were characterized for structural, optical and ethanol gas-sensing properties. X-ray diffraction studies show that all the films are polycrystalline zinc oxide in nature, possessing hexagonal wurtzite structure with (002) preferred orientation along with other peaks of low relative intensities corresponding to (100), (101), (102), (103), (112), etc. planes. Crystallite size is found to be ~40 nm. Optical absorption study reveals a band gap of ~3.37eV. The maximum gas response of the film to 100 ppm of ethanol was found to be at the operating temperature of 275°C. (author)