Synthesis, structure and red-emitting luminescence properties of Eu3+ -activated perovskite-related tungstate Ba4Na2W2O11

Eu3+-doped perovskite-related tungstate Ba4Na2W2O11 was synthesized by high-temperature solid state reaction. The red-emitting phosphor was characterized by X-ray powder diffraction, structural refinement, and scanning electron microscope and photoluminescence excitation and emission measurements. The optimal doping concentration of Ba4Na2W2O11:Eu3+ is about 7 mol%. This phosphor can be efficiently excited by near-ultraviolet and blue light to realize the stronger red luminescence than the Y2O2S:Eu3+ phosphor. The phosphor presents the dominated 5D0 → 7F1 transition at a low doping level, and the 5D0 → 7F2 transition becomes the strongest one in the Eu3+-heavily doped samples. The doping induces the luminescence color changing from reddish-orange to pure red. The photoluminescence properties of the phosphor are discussed on the base of the crystal structure.