Photoluminescence of Dy3+ activator sensitized by Ce3+ in KNaSO4 microphosphor

The KNaSO₄ microphosphor doped with Ce or Ce and Dy prepared by a wet chemical method was studied by scanning electron microscopy (SEM) and characterized by photoluminescence (PL). KNaSO₄ has a 5‐µm particle size detected by SEM. The KNaSO₄:Ce³⁺ spectrum shows a single emission band at 327 nm for an excitation of 269 nm due to 5d → 4f transition of the Ce³⁺ ion, indicating weak spin orbiting coupling of the Ce³⁺ ground state. Efficient energy transfer takes place from Ce³⁺ → Dy³⁺ sublattices indicating that Ce³⁺ could effectively sensitize Dy³⁺ (orange emission) and that the Ce³⁺ emission weakens significantly in KNaSO₄. The powder form of prepared KNaSO₄ show negligible change in morphologies and hence no effect on the particle size. The characteristics of this powder could provide improved luminescence properties. The development and understanding of this photoluminescence and the effect of Dy³⁺ on KNaSO₄: Ce³⁺ are discussed. Copyright © 2014 John Wiley & Sons, Ltd.