OPTICAL AND GAS SENSING CHARACTERISTICS OF TIN OXIDE NANO-CRYSTALLINE THIN FILM

Transparent conducting tin oxide (SnO2) thin film has been deposited on glass substrate by spray pyrolysis technique, taking starting material tin chloride solution (SnCl2.2H2O) and using ultrasonic nebulizer at substrate temperature 300±10 C. The XRD result shows a regular, smooth morphology. The deposited film was found to be polycrystalline. The average grain size of SnO2 was found to be 48.6 nm as calculated by XRD using Debye Scherrer Formula .After annealing the film in air at 400 C the grain size was 51.02 nm. The thickness of the deposited film was of the order of 500 nm. The optical absorption, transmittance, reflectance and optical conductivity have been measured. It was found that the average transmittance of the film is around 78 % at wavelength 550 nm. Finally the ethanol gas sensing properties of the film was also performed.