White light emission and energy transfer in Dy3+/Eu3+ co-doped BaLa2WO7 phosphors

Tunable full color emissive BaLa1.75 − xWO7:0.25Dy3+, xEu3+ phosphors which peaked at 484 nm (blue), 572 nm (yellow), 593 nm (orange), and 617 nm (red) were synthesized by the traditional solid-state reaction method. The as-synthesized phosphors were characterized by X-ray power diffraction, diffused reflectance spectra, photoluminescence decay curves, photoluminescence excitation and emission spectra. The photoluminescence excitation spectra range from 200 to 500 nm, including an O2−⟶W6+ charge transfer band and several 4f–4f transition peaks of Dy3+ and Eu3+. Co-doping with Eu3+ compensated the red emission component of the BaLa2WO7:Dy3+ phosphor. Furthermore, the energy transfer from Dy3+ to Eu3+ was confirmed based on the luminescence spectra and decay curves. The intense white light emissions are suggestive exploration for the potential phosphor for optical materials applications used in the ultraviolet excited white light emitting diodes.