Photoluminescence of wet chemical process-derived (Y, Gd) BO3: Eu3+/Tb3+ thin film phosphors

Using metal nitrates and boric acid as starting materials and glycerol as additives, we prepared (Y, Gd)BO3: Eu3+/Tb3+ 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 °C and the crystallinity increased with elevation of the annealing temperature. Eu3+ and Tb3+ showed their characteristic emissions in (Y, Gd) BO3 films, i.e., 5D0–7FJ (J=0, 1, 2, 3, 4) for Eu3+ and 5D4–7FJ (J=6, 5, 4, 3) for Tb3+, respectively. Both the lifetimes and PL intensity of Eu3+ and Tb3+ ions increased with increasing the annealing temperature. The optimum concentrations for Eu3+ and Tb3+ were determined to be 10 and 12 at% of Y3+ in YBO3 films. Partial introduction of Gd3+ in YBO3:Eu3+/Tb3+ films is good for enhancing the PL intensity of Eu3+ and Tb3+, and the best concentration of Gd3+ is 50 at% of Y3+ in the films.