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 4M21/24I13/2 + 4K17/2 + 4F7/2 → 6H13/2 transition at 453 nm, and two groups of strong emission peaks appear at 489 nm and 579 nm, corresponding to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions of Dy3+ ions, respectively. The decay curve results indicate that the decay mechanism of the 4F9/2 → 6H13/2 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 Å. The CIE color coordinates of x = 0.320 and y = 0.389 are located in the near white light region.

► The CIE color coordinates (x = 0.320, y = 0.389) is in the near-white-light region.
► The concentration quenching effect occurs for Ba(Y2−xDyx)ZnO5 when x > 0.07.
► The asymmetry ratio remains at about 1.04, which is independent of the Dy3+ ion.