Preparation And Luminescence Properties Of Na₅Y₄?SiO₄?₄F-based Single-phase White Light Emitting Phosphors

In the solid-state lighting,white light-emitting diodes have high efficiency,high thermal stability,long lifetime and environmental benefits compared with traditional incandescent lamps or fluorescent lamps,so they are called"green lighting sources".Phosphor is the core material of white light-emitting diodes to achieve fluorescence conversion,and its luminescent performance is one of the important factors that determine the white light-emitting diodes.However,in the system of multi-phase mixed phosphors,white light emission is unstable due to mutual absorption and the inherent differences of physicochemical properties between phosphors.Therefore,the development of single-phase white light-emitting materials with excellent luminescent performance and matching light-emitting diode chips has become a research hotspot.In this paper,we focus on the synthesis,crystal structure and luminescence characterization of single-phase white light emitting materials.The main research contents are as follows:?1?A series of single-phase Na₅Y₄?SiO₄?₄F:Eu²⁺,Tb³⁺,Eu³⁺phosphors were designed and synthesized by high-temperature solid state,and their crystal structure and luminescent properties investigated by X-ray diffractometer and fluorescence spectrometer.The chromaticity coordinates of the as-prepared phosphors under 375 nm excitation can be tuned effectively,from the light blue?0.260,0.213?to red?0.638,0.337?and eventually to white?0.407,0.373?via resonant type energy transfer and appropriate choice of color combination.?2?Na₅Y₄?SiO₄?₄F:0.01Eu²⁺/Eu³⁺phosphors were synthesized by topo-chemical reaction,and their crystal structure and luminescent properties were studied by X-ray diffraction spectrogram,excitation and emission spectra and the chromaticity coordinates.We have realized the luminescence spectrum regulation of phosphors by controlling reaction temperature and time.Under 335 nm and 365 nm excitation,the sample achieves white-light emission.