Luminescence properties of rare earth-polyoxometalate thin film deposited by sol-gel process

The rare earth (Eu³⁺, Dy³⁺)-polyoxometalate thin films were fabricated on quartz plate by the sol-gel method. The thin films were demonstrated by the luminescence spectra. The thin films exhibit the characteristic emission bands of the rare-earth ions. It is noticed that the yellow to blue intensity ratio (Y:B) of Dy³⁺ and the red to orange ratio (R:O) of Eu³⁺ in the films are different from that of the corresponding solids. Furthermore, the thin films present shorter fluorescence lifetime than the pure complexes. The reasons that were responsible for these results were also discussed.