Study On Preparation And Optical Performance Of Phosphors For White Led

Phosphor converted white LED is considered to be the most promising industrial solid lighting source as its simple production process,low production costs and excellent luminescent properties. Therefore,it has aroused more and more extensive research.In this thesis,we have prepared a series of luminescent phosphors with low-temperature combustion method,main results of the thesis are as follows:1. Ce3+-doped Ca9Y(PO4)7:Ce3+(CYP:Ce3+),(Ca, Mg)9Y(PO4)7(CMYP:Ce3+),(Ca, Sr)9Y(PO4)7:Ce3+(CSYP:Ce3+) phosphors were prepared via low-temperature combustion method. XRD showed that the as-prepared phosphor were single-phase, the particles diameter was1-5μm. The optimum molar concentration of activator in CYP:Ce3+was0.09.Excited by265nm, CYP:0.09Ce3+showed strong blue emission located at360nm.2. Optimum combustion dosage and annealing temperature were optimized, under the treatment of citric acid:metal ion=1:1(molar ratio)and900℃annealing2h, phosphor showed highest emission intensity. By doping Mg2+and Sr2+into CYP matrix, emission intensity of the phosphor was greatly enhanced, and the Optimum molar concentration of Mg2+was0.2, and the Optimum molar concentration of Sr2+was0.1, besides, the luminescence enhanced effect of Mg2+was better than that of Sr2+.3. A series of Ce3+, Tb3+single/co-doped Ca9Y(PO4)7:Ce3+, Tb3+(CYP:Ce3+, Tb3+) phosphors were prepared via low-temperature combustion method. In CYP:Ce3+, Tb3+phosphor, Ce3+â†'Tb3+energy transfer occured from5d1of Ce3+to5D3of Tb3+. CYP:Ce3+, Tb3+can be well excited in the ultraviolet (UV) range of200to325nm, and the white light can be obtained by adjusting the Ce3+, Tb3+doping concentrations, the phosphor may be used in the UV LED based W-LEDs.