Study On Preparation And Properties Of The Phosphate And Molybda Phosphors For White LED

White LED stands out in the lighting industry due to its advantages of green environmental protection,energy saving and emission reduction,small size,long life and bright colors,becoming a new generation of light source that people pursue.At present,the main way to realize white LED-phosphors conversion method has the advantages of low cost and simple process compared with other methods.The traditional conversion method of phosphors is the combination of rare earth garnet and yellow phosphors to produce white light.However,due to the weak emission in the red region of phosphors,the white LED has some defects such as low color temperature and poor color rendering.The performance of phosphors plays an important role in white LED,so the study of phosphors has attracted much attention from researchers.In this study,phosphors doped with rare earth ions(Ln=Eu²⁺,Eu³⁺,Ce³⁺,Tb³⁺)were studied,and the XRD and fluorescence properties were tested and analyzed.The main work is as follows:Ba₃?PO₄?₂:Ce³⁺and Ba₃?PO₄?₂:Tb³⁺were synthesized by high temperature solid phase method under reduced atmosphere.The optimal doping concentration of Ce³⁺in Ba₃?PO₄?₂:Ce³⁺was 3 mol%;the optimal doping concentration of Tb³⁺in Ba₃?PO₄?₂:Tb³⁺was 20 mol%and the color coordinate was?0.302,0.637?.Fluorescent materials Ba₃?PO₄?₂:Ce³⁺and Ba₃?PO₄?₂:Tb³⁺are both green fluorescent materials that can match with blue light LED chips.Ba₅?PO₄?₃F:Eu³⁺and Sr₅?PO₄?₃F:Eu²⁺were synthesized by high temperature solid phase method.Ba₅?PO₄?₃F pure phase matrix synthesis temperature is 1300?under air atmosphere,the optimal doping concentration of Eu³⁺in Ba₅?PO₄?₃F:Eu³⁺was 30 mol%,color coordinates was?0.576,0.348?,located in the red light emitter;Sr₅?PO₄?₃F pure phase matrix synthesis for the reductive atmosphere temperature 1200?,the optimal doping concentration of Eu²⁺in Sr₅?PO₄?₃F:Eu²⁺was 15 mol%,color coordinates was?0.2871,0.4036?.Flux H3BO3 can make the synthesis temperature from 1200??4h?down to 1100??4h?,the best doping concentrations of flux is 5 wt%.The optimal doping concentration of Eu³⁺in SrMoO₄:Eu³⁺was 30 mol%.When doping flux BaF₂ can make the preparation temperature from 900?to 600?.The doping of fluxes such as NH₄Cl,BaF₂,H₃BO₃,NaF and NH₄F did not affect the phase structure of the fluorescent powder,but enhanced the emission spectrum intensity.Among them,H₃BO₃ increased the emission intensity of the fluorescent powder the most,and the optimal doping concentration was7 wt%.