Synthesis and luminescence properties of a novel phosphor Ca_(2–x/2)Si_(1–x)P_xO_4:Eu^(2+)for near UV-excited white-light-emitting diodes  

作　　者：訾文文 崔天杰 于泓 李琳琳 甘树才 徐学纯 

机构地区：[1]College of Chemistry,Jilin University [2]College of Earth Sciences,Jilin University

出　　处：《Journal of Rare Earths》2013年第9期871-877,共7页稀土学报（英文版）

基　　金：Project supported by High Technology Research and Development Program Foundation of China(2007AA06Z202);National Scienceand Technology Major Projects(2008ZX05018);the Key Technology and Equipment of Efficient Utilization of Oil Shale Resources(OSR-5)

摘　　要：A novel green-emitting phosphor, Eu2＋-doped Ca2-x/2Si1-xPxO4 （0.25≤x≤0.30）, was prepared through a conventional solid-state reaction. X-ray diffraction （XRD）, photoluminescence （PL） and decay studies were employed to characterize the sample, which was assigned to P63mc space group in the hexagonal system. The effect of P-doping on theα-Ca2SiO4 was studied and P2O5 broken down by the raw material of （NH4）2HPO4 played an important role in stabilizingα-Ca2SiO4 which can only be stable at high tem-perature. The XRD patterns of the Ca2-x/2Si1-xPxO4 host were found pure and optimized when the mole fraction of P2O5 was 14.5%. The diffuse reflectance spectra of the Ca1.855Si0.71P0.29O4 and Ca1.845Si0.71P0.29O4：0.01Eu2＋covered the spectral region of 230-400 nm, implying that the phosphor was suitable for UV or near-UV LED excitation. The phosphor could be effectively excited in the near UV region with the maximum at 372 nm. The emission spectrum of the Ca1.845Si0.71P0.29O4：0.01Eu2＋phosphor showed an asymmet-rical single intensive band centered at 513 nm, which corresponded to the 4f65d1→4f7 transition of Eu2＋. Eu2＋ions might occupy two types of Ca2＋sites in the Ca1.855Si0.71P0.29O4 lattice and form two corresponding emission centers, which led to the asymmetrical emis-sion of Eu2＋in Ca1.855Si0.71P0.29O4. The effects of Eu2＋-doped concentration in Ca1.855-xSi0.71P0.29O4：xEu2＋on the PL were also dis-cussed, the optimum doping concentration of Eu2＋was 1 mol.%and the critical distance of the energy transfer was also calculated by the concentration-quenching method. The non-radiative energy transfer between Eu2＋seemed to be caused by the multipole-multipole interaction. The fluorescence lifetime of Eu2＋was found to be 0.55711μs. The results suggested that these phosphors might be prom-ising candidates used for near UV light excited white LEDs.A novel green-emitting phosphor, Eu2＋-doped Ca2-x/2Si1-xPxO4 （0.25≤x≤0.30）, was prepared through a conventional solid-state reaction. X-ray diffraction （XRD）, photoluminescence （PL） and decay studies were employed to characterize the sample, which was assigned to P63mc space group in the hexagonal system. The effect of P-doping on theα-Ca2SiO4 was studied and P2O5 broken down by the raw material of （NH4）2HPO4 played an important role in stabilizingα-Ca2SiO4 which can only be stable at high tem-perature. The XRD patterns of the Ca2-x/2Si1-xPxO4 host were found pure and optimized when the mole fraction of P2O5 was 14.5%. The diffuse reflectance spectra of the Ca1.855Si0.71P0.29O4 and Ca1.845Si0.71P0.29O4：0.01Eu2＋covered the spectral region of 230-400 nm, implying that the phosphor was suitable for UV or near-UV LED excitation. The phosphor could be effectively excited in the near UV region with the maximum at 372 nm. The emission spectrum of the Ca1.845Si0.71P0.29O4：0.01Eu2＋phosphor showed an asymmet-rical single intensive band centered at 513 nm, which corresponded to the 4f65d1→4f7 transition of Eu2＋. Eu2＋ions might occupy two types of Ca2＋sites in the Ca1.855Si0.71P0.29O4 lattice and form two corresponding emission centers, which led to the asymmetrical emis-sion of Eu2＋in Ca1.855Si0.71P0.29O4. The effects of Eu2＋-doped concentration in Ca1.855-xSi0.71P0.29O4：xEu2＋on the PL were also dis-cussed, the optimum doping concentration of Eu2＋was 1 mol.%and the critical distance of the energy transfer was also calculated by the concentration-quenching method. The non-radiative energy transfer between Eu2＋seemed to be caused by the multipole-multipole interaction. The fluorescence lifetime of Eu2＋was found to be 0.55711μs. The results suggested that these phosphors might be prom-ising candidates used for near UV light excited white LEDs.

关 键 词：solid-state reaction Eu2＋ LUMINESCENCE PHOSPHOR rare earths 

分 类 号：TN312.8[电子电信—物理电子学] TQ174.752[化学工程—陶瓷工业]