Preparation By Flux Method And The Study Of Luminescence Properties In BaAl₁₂O₁₉: Mn²⁺ And BaMgAl₁₀O₁₇:Eu²⁺ Phosphors

Recently, BaAl12O19:Mn2+(BHA) and BaMgAl10O17:Eu2+(BAM) have good luminescent properties under vacuum ultraviolet (VUV) excitation and they are successfully used in commercial green and blue phosphors respectively. Generally, in industry, both BHA and BAM phosphors are prepared by conventional solid state reaction method at high temperature (1500-1700℃). The conventional solid state reaction method has some disadvantage of high temperature, such as uneasy to control the condition, severe agglomeration and large average particles size. These shortcomings have bad effects on the luminescent properties of the phosphors. In addition, the correlative properties of the both phosphors still need to be improved to fulfill the demands the development of PDPs. BHA has a longer decay time while BAM has a bad stability. In view of the above problems, these two phosphors were prepared by the flux assisted solid state reaction method and the effect on structure, morphology and luminescent properties were discussed in detail. The major works were summarized in the following:(1) BaAl12O19:Mn2+ phosphors were successfully synthesized by single flux assisted solid state reaction and multifold flux assisted solid state reaction. The effect on structure, morphology and luminescent properties of the phosphor were investigated. The results showed that the synthesis temperature was 200℃lower than that of the conventional solid state method. Not only the morphology of the samples added flux was better than the one without flux, but also the emission intensity was improved. Moreover, a little of small ions entered into the lattice and the replacement occurred. This process influenced the energy transfer between Mn2+ and BaAl12O19. The decay time was decreased because the doubly spin and parity-forbidden transition of Mn2+ was disturbed. In addition, we explored the potential technics about the mass production of BHA phosphors.(2) BaMgAl10O17:Eu2+ blue phosphors were also successfully synthesized by flux assisted solid state reaction. The effect on structure, morphology and luminescent properties of the phosphor were also studied. The results illustrated that the synthesis temperature was 200℃lower than that of the conventional solid state method. The morphology and emission intensity were improved due to the addition of flux. In addition, the stability of BAM was improved because small ions from flux substituted for parts of ions from BaMgAl10O17, which leaded to a smaller lattice parameters and the less probability of diffused Eu2+.(3) Ba0.75Al10O17.25-BaMgAl10O17 solid solution was synthesized by flux method and the luminescent properties Eu-Mn codoped in Ba0.75Al10O17.25-BaMgAl10O17 solid solution were studied. The results showed that the emission intensity of Mn2+ was enhanced because there was an efficient energy transfer between Eu and Mn.