Synthesis and optical characterization of Eu~(2+),Tb~(3+)-codoped Sr_3Y(PO_4)_3 green phosphors

【摘要】：A series of Eu~(2+),Tb~(3+) codoped Sr_3Y(PO_4)_3(SYP) green phosphors is synthesized by a high-temperature solid-state reaction.The photoluminescence excitation and emission properties,the lifetime,concentration effect and effects of doping ions on the optical bandgap are investigated in detail.SYP:0.05Eu~(2+) phosphor shows an intense and broad excitation band that ranges from 220 nm to 400 nm,and it exihibits a bright green emission band with CIE chromaticity coordinates(0.189,0.359) under 350 nm excitation.The green emission of SYP:0.03Tb~(3+) can be intensified by codoping with Eu~(2+),and the energy transfer mechanism between them is demonstrated to be a dipole–dipole interaction.Upon 350 nm excitation,the SYP:Eu~(2+),Tb~(3+) phosphors show two dominating bands peaked at 466 and 545 nm,which are assigned to the 4f~65d~1-4f~7 transition of the Eu~(2+) ions and the ~5D_4-~7F_5 transition of the Tb~(3+) ions,respectively.The optimal doping concentrations of Eu~(2+) and Tb~(3+) in SYP host are 5 and 15 mol%,respectively.Results indicated that SYP:Eu~(2+),Tb~(3+) phosphors are potentially useful as green-emitting phosphors for white light-emitting diodes.