Near white light emission of BaY2ZnO5 doped with Dy3+ ions

Controlling activator concentrations to possess near white light emission of BaY2ZnO5 doped with Dy3+ ions was performed using high energy vibrating milled solid-state reaction. The XRD patterns show that all of the peaks can be attributed to the BaY2ZnO5 orthorhombic structure, because that the BaY2ZnO5 and BaDy2ZnO5 are isostructures with a space group of Pbnm. Under ultraviolet (355 nm) excitation, a weak group of emission peaks appear for the M-4(21/2) I-4(13/2) + K-4(17/2) + F-4(7/2) -> H-6(13/2) transition at 453 nm, and two groups of strong emission peaks appear at 489 nm and 579 nm, corresponding to the F-4(9/2) -> H-6(15/2) and F-4(9/2) -> H-6(13/2) transitions of Dy3+ ions, respectively. The decay curve results indicate that the decay mechanism of the F-4(9/2) -> H-6(13/2) transition is a single decay component between Dy3+ ions only. In addition, the asymmetry ratio, which is independent of Dy3+ ion concentration, remains at about 1.04, indicating that the symmetry of Dy3+ ions does not change with concentration. Concentration quenching occurs with x values above 0.07, and the critical distance is about 11.93 angstrom. The CIE color coordinates of x = 0.320 and y = 0.389 are located in the near white light region. (C) 2011 Elsevier B. V. All rights reserved.