The Study On Preparation And Photoluminescence Of Rare-earth Silicates Phosphors For White-LED

White LED is a new light source. It is expected to be a good candidate as a new generation of illumination light source substituting for incandescent lamps or fluorescent lamps because of environment friendly, solid-state,high luminescent efficiency,long-lifetime, and so on, which is unlike traditional light source. So it has broad prospects. Silicates are excellent hosts for photoluminescence (PL) materials for their various crystal structures and high physical-chemical stability. The research on preparation and photoluminescence of Rare-earth silicates phosphors for White-LED have great significance..In this paper,series samples of white LED phosphor Ca2SiO4: Eu3+ Ca2SiO4:Dy3+, Sr2SiO4:Dy3+, Eu3+ has been synthesized by high temperature solid state. The optic spectrum coordinates, color coordinates, color temperature and color rendering index (CRI) in near-UV is demonstrated. Based on the current demands about the development of white LED phosphors, our investigation is mainly focused on the exploitation of a new and efficient red phosphor and the exploration of a single matrix white phosphor.The X-ray powder diffraction data of series samples Ca2SiO4:Eu3+, Ca2Si04:Dy3+, Sr2SiO4:Dy3+,Eu3+ have good agreement with JCPDS standard card, which shows that the synthetic material is alkaline earth metal silicate.The excitation spectra of Ca2SiO4:Eu3+ is at about 594,617,652 and 702nm attribute to the 5D0â†'7F1,5D0â†'7F2,5D0â†'7F3,5D0â†'7F4 transition of Eu3+. There is a strong excitation spectra at 617nm attribute to 5D0â†'7F2. Its emission color coordinates and color temperature could be changed by tuning concentration of rare-earth activator Eu3+.So the phosphor Ca2SiO4:Eu’+is an efficient red phosphor excited by near-UV.The emission light of Ca2SiO4:Dy3+ is at 482nm (Blue) 575nm (yellow) under 386nm attribute to 4M21/2â†'6H13/2,4F9/2â†'6H15/2,4Fg/2â†'6H13/2 transition of Dy3+.The excitation spectra mainly near 575nm. But the emission color of red is dim. Its emission color coordinates and color temperature could be changed by tuning concentration of rare-earth activator Dy3+. But the range of color coordinates is small.Synthesized the phosphor Sr2SiO4:Dy3+,Eu3+, The PL spectrum coordinates, color coordinates, color temperature and color rendering index (CRI) in different near-UV and concentration of rare-earth activator Eu3+ is studied.