Luminescent self-assembled thin films based on rare earth-heteropolytungstate

摘要

Rare earth (Eu~(3+), Dy~(3+))-heteropolytungstate thin films were fabricated by self-assembly method successfully. The thin films give off strong fluorescence, which can be observed by eyes upon UV irradiation. The characteristic emission behaviors of the rare earth ions in self-assembled thin film were investigated compared with those of the corresponding solids. It is noticed that the intensity ratio between ~5D_0→~7F_2 and ~5D_0→7F_1 of Eu~(3+) and the intensity ratio between ~4F_(9/2)→~6H_(13/2) and ~4F_(9/2)→~6H_(15/2) of Dy~(3+) in the self-assembled films are different from those of the corresponding solids. Furthermore, the self-assembled films present shorter fluorescence lifetimes than the corresponding solids. The reasons for these results have been discussed.