Preparation And Characterization Of YAG:Ce Phosphor By Solid-state Reaction

White-light emitting diode (w-LED) has been widely applied in many areas because of numerous advantages, such as energy saving, high efficiency, long lifetime and reliability. The common way to fabricate w-LED device is using YAG:Ce as a broad band yellow phosphor coated on the blue LED chip. White-light emitting diode is mentioned as the forth generation illuminate lamp, which has huge market. At the same time YAG: Ce phosphor have become hot spots.The progress in YAG:Ce Photoluminescence Material has been reviewed in this paper. This paper introduces several synthetic methods of YAG:Ce phosphor and summarizes their strongpoints and weakpoints. YAG:Ce phosphor particles were prepared by solid-state reaction at 1400°C. Y2O3, CeO2 and Al(OH)3were the main raw materials as BaF2 and H3BO3 added together as flux. And the phosphors were prepared by co-melting method at 1100°C. Y(NO3)3·6H2O,Y2O3,CeO2 and Al(NO3)3·9H2O were the starting materials,Y2O3 was used as crystal seeds. The reaction temperature was greatly decreased.In the article, Matrics replace and co-doping by using the other rare earth ions. A series of YAG: Ce phosphors have been prepared, and their luminescent properties were studied. The products were characterized by means of XRD, all systems have cubic garnet structure. The phosphors were characterized by luminescence spectrum. A maximum PL intensity was obtained for about 6mol% Ce3+ additions. The result shows that the emission spectra show a red shift when Y was replaced by Gd, La or Tb, and a blue shift was observed when Y replaced by Lu. There are three sharp emission peaks ( 566, 602, 616 nm) exist when Y replaced by Sm. From the emission spectra of the YAG:Ce,Pr , it is clear that both a broad emission band and a sharp emission peak ( 610 nm) exist. To improve CRI of YAG:Ce phosphor with enhancing emission intensity in red spectral region , red emission needs to be added to the broad yellow emission .The sharp emission peaks in red spectral region and a red shift of emission band are efficient.