Research On Alkaline Earth Silicate White Emitting Phosphors Activated With Rare Earth For LED

The study on the fabrication and properties of white phosphor in LED is getting more and more attention with the extension of applied field and the development of preparation technology in white LED, especially, the fabrication and properties of rare earth activated alkaline earth silicate white emitting phosphor excited by ultraviolet light.In this paper, Sr₂MgSiO₅:Eu²⁺ and Sr₂Ca₂Si₃O₈Cl₄:Eu²⁺ white emitting phosphors with stable property were synthesized by the high-temperature solid state reaction method. The structure and the luminescent properties of the samples were characterized by X-ray diffraction and spectrometer. The influence of synthetical temperature, reaction time, fluxes, the concentration of Eu²⁺ on the luminescent properties of the samples were systematically studied.The results indicate that phosphor of Sr₂MgSiO₅:0.01Eu²⁺ calcined at 1100℃for 2h with Li₂CO₃ fluxing agents 3wt% has the optimum luminescence property, and the luminescence spectrum is composed of two emission bands peaking at 460nm and 530nm respectively under excitation of 400nm. Phosphors Sr₂MgSiO₅:Eu²⁺ showed much higher intensity due to La³⁺ dopeing. Phosphor of Sr₂Ca₂Si₃O₈Cl₄:0.01Eu²⁺ calcined at 1000℃for 2h with Li₂CO₃ fluxing agents lwt% has the optimum luminescence property, and Sr₂Ca₂Si₃O₈Cl₄:Eu²⁺ emits white light under excitation of 343nm, the luminescence spectrum is a broadband spectrum peaking at 450nm and 555nm respectively.