Photoluminescence of wet chemical process-derived (Y, Gd) BO_3: Eu~(3+) /Tb~(3+) thin film phosphors

摘要

Using metal nitrates and boric acid as starting materials and glycerol as additives, we prepared (Y, Gd)BO_3: Eu~(3+) / Tb~(3+) thin film phosphors by a wet chemical process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy, photoluminescence (PL) spectra as well as lifetimes were employed to characterize the resulting samples. The results of the XRD and FT-IR indicated the films began to crystallize at 700℃ and the crystallinity increased with elevation of the annealing temperature. Eu~(3+) and Tb~(3+) showed their characteristic emissions in (Y, Gd) BO_3 films, i.e., ~5D_0-~7F_J (J= 0, 1, 2, 3, 4) for Eu~(3+) and ~5D_4-~7F_J (J = 6, 5, 4, 3) for Tb~(3+), respectively. Both the lifetimes and PL intensity of Eu~(3+) and Tb~(3+) ions increased with increasing the annealing temperature. The optimum concentrations for Eu~(3+) and Tb~(3+) were determined to be 10 and 12 at% of Y~(3+) in YBO_3 films. Partial introduction of Gd~(3+) in YBO_3:Eu~(3+) /Tb~(3+) films is good for enhancing the PL intensity of Eu~(3+) and Tb~(3+) , and the best concentration of Gd~(3+) is 50at% of Y~(3+) in the films.