The design and synthesis of new double perovskite (Na,Li)YMg(W,Mo)O6:Eu3+ red phosphors for white light-emitting diodes

Doubly ordered double perovskites with AA'BB'O-6 stoichiometry are promising new host materials for Eu3+ activator ions. In this paper, double perovskite (Na, Li) YMg(W, Mo) O-6: Eu3+ phosphors were synthesized by a high-temperature solid-state method and the effect of cation substitutions in this series of monoclinic-type NaYMgWO6 compounds was investigated in order to control the photoluminescence properties. The composition modulation and structural evolution of (Na, Li) YMg(W, Mo) O-6: Eu3+ were studied by powder X-ray diffraction and Rietveld refinement. The microstructure and composition of the phosphor materials were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. All compounds' photoluminescence properties were measured, and the luminescence properties were related to the structural properties of the materials. The (Na, Li) YMg(W, Mo)O-6: Eu3+ phosphors emit intense red light dominated by the D-5(0) -> F-7(2) transition at similar to 618 nm, along with other characteristic transitions from Eu3+ 4f-4f transitions when excited at similar to 395 nm and similar to 466 nm. The red emission intensity of Eu3+ reaches a maximum for LiYMgW0.9Mo0.1O6: Eu3+ phosphor, which exhibits high quantum efficiency and excellent thermal stability. The obtained results suggest that these new double perovskites doped with Eu3+ are promising red phosphor candidates for white light-emitting diodes. (C) 2017 Elsevier B.V. All rights reserved.