Abstract:

ZnO/SiO₂ (ZSO) composite thin films were deposited on glass substrates by means of sol\|gel method. The microstructure, crystal structure, transmission and photoluminescent properties of the samples were characterized by SEM, XRD, UV\|Vis and PL, respectively. The results of SEM show that double\|layer structure can be observed clearly. The particles became larger as the annealing temperature rised and partly agglomerated. The results of XRD indicate that hexagonal wurtzite ZnO was formed after annealing, and with the annealing temperature rising, the peak intensity increased, while particle size also increased. The results of UV\|Vis indicate that there were absorption edges for both ZnO and SiO₂. In double\|layer composite thin films, the two different materials ZnO and SiO₂ caused curves near 360   nm to be unsmooth, and the edges to be blue shift at the same time. The samples have a higher transmittance having been annealed at 400 ℃. The PL spectra show that there were emission peaks in the ultraviolet region and blue region separately when the samples were excited at  355 nm. The photoluminescent intensity caused by defects weakened as the defects density reduced with the rising annealing temperature.

Key words: composite thin film, sol\, gel, structure, optical property