硅酸盐荧光粉的掺杂及其发光性能分析-材料物理与化学专业论文.docxVIP

华中科技 大学硕士 学 华 中 科 技 大 学 硕 士 学 位 论 文 II II Abstract White light-emitting diode (WLED) is a new-style solid-state lighting source, currently，in the market which is mainly prepared by phosphor-converting method. In the technology of phosphor-converting, phosphor is allimportant for the luminous efficiency, working life and other properties of WLED. As phosphors used in WLED, due to the advantage such as the wider excitation spectra and excellent color rendering, silicate with rare earth doping is receiving more and more attention. In the dissertation, a green phosphor Li2Sr1-xBaxSiO4: 0.01Eu2+,0.0075Ce3+ and the other red phosphor Li2SrSiO4: Eu3+ were prepared by high temperature solid state reaction, using fluorescence spectrophotometer, X-ray Diffractometer (XRD) and scanning electron microscope(SEM) to test their crystal structure、fluorescence and micro morphology properties. The green phosphor Li2Sr1-xBaxSiO4: 0.01Eu2+,0.0075Ce3+ was prepared under a reductive atmosphere. The phosphors were synthesized: on the basis of the crystal structure and spectral analysis, and the possible preparation technology which may affect the luminescence property were investigated in details, including the sinter point, soaking time, excitation and emitting wavelength and doped ions with its concentration，we obtained the optimum calcination conditions: 850℃ and 2h. The optimum additive amount of Eu2+ is 0.01mol, and Ce3+ is 0.0075mol, Ba2+ is 0.8mol. With the increase of Ba2+ ions, emission spectrum have blue shift phenomenon to appear. XRD analysis shows that the phosphor Li2Sr1-xBaxSiO4: Eu, Ce belongs to the hexagonal system. The phosphor is intensive green-yellow light which has a broad emission spectrum. The emittion spectrum ranges from 500nm to 525nm and the peak appears at 513nm. The excitation spectrum ranges from 300nm to 450nm and the peak appears at 385nm, seated near ultraviolet area. The red phosphor Li2SrSiO4: Eu3+ was also prepared by high tempe