Synthesis And Luminescence Properties Of Rare-Earth Doped Molybdate And Borate

With the continuous progress of science&technology and people’s material life,a gradual increase in the requirements of high-quality phosphors. Currently, the mostwidely used is rare-earth tri-color phosphor, in which the luminescence of Eu³⁺, Eu²⁺,Tb³⁺or Mn²⁺activated the matrix material of silicate, borate or aluminate. However,the red phosphors have some shortcomings, which inclde that the low luminousefficiency or bad monochromatic and others. More attention has been paid to explorethe development of new substrate materials or synthetic methods, because the type ofmatrix material is a key factor affecting the luminous efficiency.In this paper, four phosphors, which include YBO₃:Eu³⁺, CaMoO₄:Eu³⁺,NaY（MoO₄）₂:Eu³⁺&Zn₄O（BO₂）6:Tb³⁺,Ce³⁺, were synthesized by hydrothermalmethod at low temperature. The structural, optical and morphology of four phosphorshad been studied by Scanning Electron Microscopy（SEM）, Photoluminescence（PL）,X-Ray powder Diffraction（XRD）, Fourier Transform Infrared Spectroscopy（FT-IR）and Energy Dispersive X-Ray Spectroscopy （EDS）. In addition, the dopedconcentration of rare-earth and the sensitized ion influence on the luminescence ofproduct.Borate and molybdate phosphors doped Eu³⁺ion were synthesized byhydrothermal and the lattice type of matrix material have effect on the transition selectof Eu³⁺ion. CaMoO₄and NaY（MoO₄）₂have non-symmetric lattice structure and theconfusion of lattice was increased after add Eu³⁺ion, which promote the5D0â†'7F1electric dipole transition and result in the red emission of615nm. When the material isYBO₃, the doped Eu³⁺ion occupy inversion center that promote the5D0â†'7F1transition of magnetic dipole transitions and result in the orange emission of593nm. Inaddition，the high concentration of doped Eu³⁺ion has the influence concentrationquenching, and we found the optimum doping concentration for the three phosphors.We also compared the R/O and the fluorescence spectroscopy under differentexcitation spectrum.Zn₄O（BO₂）6:Tb³⁺green phosphor was synthesized by means of doped the Tb³⁺ion to the Zn₄O（BO₂）6matrix material. The results of fluorescence spectroscopyindicate that there are two obvious emission peaks of the product, which included thestrongest green peak of545nm and the emission peak of492nm. When co-doped theCe³⁺ion into the Zn₄O（BO₂）6:Tb³⁺phosphor, the luminous intensity ofZn₄O（BO₂）6:Tb³⁺, Ce³⁺increased the number of times and the absorption bands occursthe red-transfer influence. Moreover, Tb³⁺ion and Ce³⁺ion doping concentration onluminescence were investigated, the results show that the best co-doping ratio ofTb³⁺:Ce³⁺is1:2.