Impact of annealing duration on spray pyrolysis deposited nanostructured zinc oxide thin films

• ZnO thin films were deposited on glass substrates using spray pyrolysis technique.
• Ostwald ripening was observed as an effect of annealing duration.
• Increase in crystallite size as a function of annealing duration was observed.
• Band gap was found to be decreased from 3.31 to 3.26 eV.
• Transmittance and electrical conductivity were increased as annealing time increased.

The effect of annealing duration on structural, morphological, optical and electrical properties of spray deposited nanostructured ZnO thin films was investigated. Films were deposited on glass substrates at the substrate temperature of 523 K subsequently post annealed at 673 K for 6 h, 12 h and 24 h durations. X-ray diffraction pattern of the films confirmed the polycrystalline nature with hexagonal wurtzite structure. The gradual grain growth along the c axis and increase in crystallite size with reference to annealing duration were confirmed by X-ray diffraction data. Scanning electron micrographs of the films revealed the grain growth as an effect of annealing duration. Optical band gap was found to be decreased from 3.31 to 3.26 eV when the annealing period was increased from 0 to 24 h. Film thickness and electrical conductivity were found to be decreased and increased respectively as the annealing duration was increased.

Figure optionsDownload as PowerPoint slide