Preparation, structure and luminescent performance of Na₂SiF₆:Re³⁺ (Re³⁺ = Eu³⁺, Tb³⁺, Ce³⁺) powders

A series of Na₂SiF₆:xRe³⁺ (Re³⁺ = Eu³⁺, Tb³⁺, Ce³⁺) phosphors were prepared by co-precipitation method. The structure and luminescence performance of the materials were characterized by XRD, TG–DSC, TEM, HRTEM, EDS, FT-IR, fluorescence spectra and the calculated CIE coordinates. The results show that under the excitation of specific UV light, Na₂SiF₆:xEu³⁺, Na₂SiF₆:yTb³⁺ and Na₂SiF₆:zCe³⁺ single-doping materials exhibit the characteristic emission of Eu³⁺ (⁵D₀ → ⁷F₂, red), Tb³⁺ (⁵D₄ → ⁷F₅, green) and Ce³⁺ (5d → 4f, blue), respectively. In the Na₂SiF₆:xEu³⁺–yTb³⁺–zCe³⁺ three-doping system, Na₂SiF₆:0.03Eu³⁺–0.07Tb³⁺–0.07Ce³⁺ material is representative. With the increase of exciting wavelength of UV light, the emission color of the material realizes tunable from white light to cool white light, warm white light and red orange light. And the luminescence of the material is closest to the ideal white light under excitation of UV light at 290 nm. So this phosphor can be promised as a single-component tunable white phosphor for application in white LEDs.