Synthesis And Photoluminesence Properties Of Halogen Apatite Phosphors Excited By Near-ultraviolet

The LEDs are deep all around us,the gorgeous stage lights in the square,the programs with songs and dances on the TV,the street lamps illuminated on the streets,the table lamps on the desks,etc.In short,it is everywhere in our lives.In today's society,there are roughly three ways to achieve LED white light.The first is to match the blue chip with the yellow phosphor that can be excited by blue light and emit yellow light;the second is to mix the RGB three-color chips to form white light;the third is to pass the near ultraviolet chip and the red,green and blue The three primary color chips are assembled to achieve white light.The three methods have their own advantages and disadvantages.The combination of near ultraviolet light and phosphor is a hot spot.In this paper,phosphate is selected as the matrix material,and the luminescence performance is explored by matching with Eu²⁺.A series of fluoroapatite phosphors were prepared by solid state reaction.Blue phosphor Ca₅(PO₄)₃F:Eu²⁺crystal structure and luminescence properties.From the XRD pattern,it can be seen that the samples required for the experiment can be prepared at 1100?,1200?,and1300?,and the Eu²⁺added to all the samples does not cause the change of the lattice,and the sample is pure phase.It can be seen from the excitation spectrum that the sample can be excited by ultraviolet and near-ultraviolet light at 270-370 nm.Using 293 nm and 350 nm light for excitation,a blue emission peak at 450 nm can be obtained.By analyzing the emission spectra of different Eu²⁺doped Ca₅(PO₄)₃F,it can be concluded that the optimal doping concentration of Eu²⁺is 3.0mol%,so this sample has certain application prospects in blue phosphors.The traditional solid state reaction method is also used to prepare Sr₅(PO₄)₃F:Eu²⁺hosphor.The XRD pattern analysis shows that the sample prepared at 1100?can correspond to the standard card,and Sr₅(PO₄)₃F is hexagonal crystal structure.The excitation spectrum of Sr₅(PO₄)₃F:Eu²⁺sample is from 270-370 nm.The excitation spectrum is broad spectrum and can match well with ultraviolet and near ultraviolet chips.Sr₅(PO₄)₃F:Eu²⁺phosphor can get a deep blue emission peak at 437 nm under the excitation of near ultraviolet light at 350 nm,which can also explain that Sr₅(PO₄)₃F:Eu²⁺phosphor excited blue fluorescence in near ultraviolet The powder has certain potential.Under the structure of A₅(PO₄)₃F fluorophosphate,by changing the doping ratio of Ca and Sr ions,the effect of spectrum regulation can be achieved.Sr₅(PO₄)₃F:Eu²⁺phosphor can obtain an emission peak of 437 nm under 350 nm excitation;And Sr₅(PO₄)₃F:Eu²⁺phosphor Sr is gradually replaced by Ca ions,the phenomenon that the spectrum will be red-shifted and then blue-shifted,and when the ratio of Ca to Sr reaches 1:1,the sample is red-shifted The distance is farthest,using 350 nm light excitation to get an emission peak of 453 nm;Ca₅(PO₄)₃F:Eu²⁺phosphors get an emission peak of 450 nm under 350 nm excitation.Through this phenomenon,the spectrum adjustment effect in the blue region can be effectively achieved by changing the doping ratio of Ca and Sr.This discovery is expected to be applied to n-UVwled blue phosphors.The blue phosphor Ca₁₀(PO₄)₆Cl₂:Eu²⁺in chloroapatite was compared and analyzed by deposition-precipitation method and solid state reaction.Through analysis and characterization,to explore the effect of different preparation methods on Ca₁₀(PO₄)₆Cl₂:Eu²⁺phosphor.Through analysis and characterization,the effect of different preparation methods on Ca₁₀(PO₄)₆Cl₂:Eu²⁺phosphor is explored.XRD patterns indicate that both methods can produce pure phase Ca₁₀(PO₄)₆Cl₂.Analysis of the crystal structure There are two different Ca sites in Ca₁₀(PO₄)₆Cl₂.Under the same Eu²⁺doping concentration,the samples prepared by the two preparation methods can get the blue emission peak at 453 nm.However,the luminous intensity of the samples prepared by the deposition precipitation method is 110%higher than the samples prepared by the traditional solid state reaction method.The morphology and particle size analysis of the surface of the phosphor can clearly see that the Eu²⁺prepared by the solid state reaction method has obvious large-area aggregation,and the Eu²⁺in the sample prepared by the deposition precipitation method can be more uniformly dispersed in Sample surface.Different preparation methods can effectively improve the luminous intensity of Ca₁₀(PO₄)₆Cl₂:Eu²⁺phosphor,which has great potential value in the blue phosphor of n-UVwLED.