Synthesis and luminescent properties of LiLaSiO4:Dy3+, Eu3+ phosphors for white LEDs

A range of LiLaSiO4:xDy3+, yEu3+ phosphors were synthesized by high-temperature solid-phase method. Its phase composition, microstructure, luminescence properties, energy transfer mechanism, decay life and CIE color coordinates of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrometer. In LiLaSiO4:xDy3+ phosphors, as the doping concentration of Dy3+ increases, the luminescence intensity of Dy3+ increases first and then decreases, the concentration quenching point of Dy3+ was x ​= ​0.04. In LiLaSiO4: 0.04Dy3+, yEu3+ phosphors, as the doping concentration of Eu3+ increase, the luminescence intensity of Dy3+ decreases gradually. However, the luminescence intensity of Eu3+ increases first and then decreases, the concentration quenching point of Eu3+ was y ​= ​0.05. In LiLaSiO4:0.04Dy3+, yEu3+ phosphors, there is energy transfer between Dy3+ - Eu3+. When the concentration of Eu3+ was y ​= ​0.20, the energy transfer efficiency is 62.50%, The energy transfer mechanism of electric dipole-electric dipole LiLaSiO4:xDy3+, yEu3+ phosphor. By tuning the doping concentration percentage of Eu3+ and Dy3+, the LiLaSiO4:xDy3+, yEu3+ phosphors can realize the lighting by single-matrix warm white light-emitting diodes (WLEDs).