Preparation And Characterization Of Novel Silicate Phosphors For W-LED

Silicate worded as matrix material, meanwhile the trivalent dysprosium ion and trivalenteuropium ion as the activator， Ca1.7Mg0.3SiO4:Dy3+phosphors and Y2-xSiO5:xEu3+in redphosphor for white LED where manufactured by a solid-state method. The phase structure,particle morphology and particle size where characterized by using XRD、SEM and grain-sizeanalyzer. In order to find out whether those phosphors Ca1.7Mg0.3SiO4:Dy3+and Y2-xSiO5:xEu3+suitable for white LED, the luminescent properties of the phosphors where investigated by afluorescent spectrometer. The electronic transitions of the phorsphors with the trivalentdysprosiumion and trivalenteuropium ionswerefurtherstudied.The Ca1.7Mg0.3SiO4:Dy3+phosphor used for white LED was synthesized by a sol-gelmethod. By means of orthogonal test, the influences of Dy3+doping concentration,sintering temperature and reservation time on the properties of the phosphor werediscussed. In order to optimize the synthesis conditions, the phase structure, particlemorphology and size distribution of the phosphor were characterized by XRD and SEM,respectively. The excitation and emission spectra of Ca1.7Mg0.3SiO4:Dy3+phosphor wasinvestigated. The results showed that Ca1.7Mg0.3SiO4:Dy3+fluorescence powder sintered at1300℃for3.5h appeared emission peaks at482.0nm (4F9/2�'6H15/2transition) and577.0nm (4F9/2�'6H13/2transition), respectively under a near ultraviolet excitation at351.0nm(6H15/2�'6P7/2transition). The chromaticity coordinate of the fluorescence powder was(0.2574,0.3314), located at the white region.The Y2-xSiO5:xEu3+red phosphor for white LED was synthesized by a sol-gel method.The structure, particle morphology and particle size of the phosphor were characterized bymeans of XRD, SEM and particle size analyzer. The influence of the impact of Eu3+dopingconcentration on the properties of Y2-xSiO5:xEu3+red phosphor was analyzed by afluorescence spectrometer. The results showed that Y2-xSiO5:xEu3+phosphor sintered at1150℃for3h appeared emission peaks at613.0nm (5D0�'7F2transition), under a near excitation at396.0nm (7F0�'5L6transition). The chromaticity coordinate of the phosphorwas (0.6406,0.3314), located near the red region.