The Preparation And Characterization Of Sr₃Si(Ge)O₅: Eu²⁺ Phosphor For White Light Emiting Diode

The Sr3SiO5:Eu2+ phosphor for White Light Emitting Diode (WLED) is synthesized by the solid-state reaction method. The crystal structure and luminescent properties are influenced by the factors such as Sr/Si ratio, the doping concentration of the flux BaF2 and Eu2+ ion,the temperature as well as the concentration of Ge (respectively 0 mol,0.1mol,0.25 mol,0.5 mol,0.75 mol,0.9 mol and 1 mol) and Ba (respectively 0 mol,0.1 mol,0.15 mol,0.2 mol%,0.25 mol,0.3 mol,0.35 mol,0.4 mol,0.45 mol and 0.5 mol). And the phase and spectrum are analyzed by XRD and PL. To the Sr3SiO5:Eu2+ phosphor, the optimal results show that the Sr/Si ratio is 3;the doping concentration of BaF2 and Eu2+ ion is lwt% and 7mol%;and the best temperature is 1380℃.The Sr3SiO5:Eu2+ phosphor exhibits a strong yellow emission centering at about 569nm.The emission peaks of the Sr3Si1-yGeyO5:Eu2+ phosphor are 502nm,550nm,590nm and 610nm.While the range of the Sr3-xBaxSiO5:Eu2+ phosphor emission spectrum is 566nm～576nm. Under the temperature of 1360℃～1420℃,the atmosphere of N2/H2(90/10) and 6 hours, pure phases of the Sr3SiO5:Eu2+ and Sr3GeO5:Eu2+ phosphor are synthesized. And the Sr3-xBaxSi05:Eu2+ phosphor is also prepared. The range of the excitation spectrum of this kind of silicate phosphor investigated in this paper is 300nm～520nm with high exciting intensity in 460n (blue light),and it can be widely applied in the WLEDs excited by the ultraviolet, near- ultraviolet and blue chips.