Preparation And Luminescence Properties Of Sr_2-xBa_xSiO₄:nEu²⁺, MCe³⁺ Phosphor For WLED

White light-emitting diode(WLED in short) is the most important lighting source of solid state lighting,whose development is not only best for sustainable development of the society and environment,but also can promote the development of LED industry and other related industries, improving competitiveness of lighting industry in our country. Because the excitation source is semiconductor of ultraviolet C, ultraviolet A and blue emission, and higher output power, therefore, the specific requirements are desired, while for those requirements to study on the special luminescence materials of WLED is the new research topic. Recent years, the development on the phosphors of LED is fast, but there are still many problems on the luminous efficiency, color rendering index and so on. So, studying the high luminous efficiency and well stability phosphors is still urgency for satisfying on the demands of technology development of high brightness, high luminous efficiency and good color rendering index for WLED.In this paper, the Sr2SiO4:Eu phosphors were synthesized by traditional solid-state reaction, and the possible ingredients which may affect the luminescence property were investigated in details, including the synthesizing system, excitation wavelength, doped ions and its species. Luminescence properties were investigated under the condition of different doping amount of Eu2+,studying the effects on phosphors by different doping amount of Ba2+ and Ce3+.The phosphors were characterized by spectrophotometer, X-ray diffraction, scanning electronic microscopy and relative brightness instrument.The results shows us that:Using solid-state reaction method synthesized the Sr2SiO4:Eu phosphor powders at 1250℃for 3h. The excitation wavelength for the pure phase Sr2SiO4 phosphor is in the UV region; According to analyzing the emission and excitation spectra of different doping amount of Eu2+ in the Sr2SiO4:Eu phosphor, determined the concentration value of Eu2+ fluorescence quenching is 0.01 mol. The further doping alkaline earth metal ions Ba2+ and rare earth metal ions Ce3+,studying the changes of the fluorescence, determined the concentration value of Ba2+ is 0.8mol and Ce3+ is 0.0075mol. It shows that the rich of Sr phase in the SrBaSiO4:Eu phosphors have a higher luminous efficiency, and for the purpose of doping Ce3+ played the sensitizer role. Ce3+ can absorb and transfer the excitation energy, sensitized Eu2+. The emission spectra of the rare earth metal sensitizer ion doped phosphors is related the concentration value of the rare earth metal sensitizer ion:When the concentration of the rare earth metal sensitizer ion is low, spectral intensity is weak; While the concentration of the rare earth metal sensitizer ion is high, firstly, the spectral intensity increases higher gradually, then because of sensitizer fluorescence quenching,the spectral intensity decreases, as for the concentration of the rare earth metal sensitizer ion is higher. So in this paper, the best concentration value of Ce3+ is 0.0075mol. And we can obtain the better luminescent properties Sr1.2Ba0.8SiO4:0.01Eu,0.0075Ce phosphor.