Study On Synthesis And Luminescence Properties Of LaMgAl₁₁O₁₉ Doped With Rare Earth

The phosphor particles for PDP applications should have good luminescent characteristics under vacuum ultraviolet (VUV) light coming from the resonance radiation line of Xe atoms(147nm) and from the excited state of molecular Xe(172 nm). The representative PDP phosphors are (Y,Gd)BO₃:Eu³⁺(red), Zn₂SiO₄:Mn²⁺ (green), and BaMgAl₁₀O₁₇:Eu²⁺(BAM) (blue). These phosphor materials, however, still have several problems such as poor color purity(red), too long time of persistence (green), and unstable during the baking processes(blue). So,we choose the host lattice LaMgAl₁₁O₁₉(LMA), which has a distorted magnetoplumbite structure and consists of spinel-like blocks separated by mirror planes, has its particular excellence: (1) Eu³⁺,Tb³⁺ and Eu²⁺ all can replace La³⁺ on the mirror planes to form red, green and blue-emitting luminescent center. (2) Mn²⁺ substitutes Mg²⁺ which locates centrally in Al—O tetrahedron can lead an green emission of about 520nm. In addition, high level excited state of active ion, energy band structure of the host and the energy transfer between active ions can be lucubrated through the study on spectra of rare-earth doped LaMgAl₁₁O₁₉ to supply important academic guidance to the design and synthesis of new efficient PDP phosphors.Study on photoluminescence properties of LaMgAl₁₁O₁₉-based phosphors were mainly focused on UV region and few in VUV region. The research in VUV region only gave the spectral characteristic of a special doping-content LaMgAl₁₁O₁₉:R(R=Tb³⁺, Mn²⁺). In order to explore new PDP phosphors, we investigate into the luminescent properties of LaMgAl₁₁O¹⁹:R(R= Eu³⁺, Tb³⁺, Eu²⁺ Mn²⁺) under UV and VUV excited. Also, Gd³⁺ is co-doped with Tb³⁺ in LaMgAl₁₁O₁₉ in order to enhance the Tb³⁺ luminescence, Eu²⁺ or Gd³⁺ is co-doped with fixed Mn²⁺-content for enhance the Mn²⁺ luminescence.The result suggest that (La,Gd)MgAl₁₁O₁₉:R(R= Tb³⁺, Eu²⁺, Mn²⁺) phosphors could be potential green phosphor for the application in PDP.