Preparation And Photoluminescent Properties Of Eu²⁺,Mn²⁺Activated Hexaaluminate Phosphors

Due to its thin panel, a slight weight, an extensive visual angle, a large screen size, high-speed response with emissive, high contrast, more saturated colors etc, Plasma display panels (PDPs) were widely used in displays, especially in3D and high definition displays for its characteristics of higher response speed. The quality of Vacuum ultraviolet (VUV) luminescent materials is the key point of PDPs such as luminescence efficiency, color purity, decay time and stability play important role on the quality of displays. Phosphors based on hexaaluminates were widely used as PDP commercial materials, especially the blue phosphor BaMgAl10O17:Eu2+and green phosphor BaAl12O19:Mn2+, both of which exhibit excellent luminescent properties. However, there still some un-solved problems restrict its application in PDP, especially in3D displays, such as the degradation of BaMgAl10O17:Eu2+, the luminescent intensity and decay time of BaAl12O19:Mn2+. In this literature, BaMgAl10O17:Eu2+and BaAl12O19:Mn2+were choosed as the research object, and some experimental work were did for develop the luminescent mechanisms of these two phosphors in Vacuum ultraviolet and to improve its luminescent properties, such as some thermal processes, doping some other ions and synthesize nano phosphors. The main works were contained as below:1. Blue phosphor BaMgAl10O17:Eu2+was annealed in air, nitrogen and reduction atmosphere for different times, the luminance degradation was evaluated, and the influence of defects in the thermal degradation was discussed; meanwhile, the self-reduction of Eu3+in BaMgAl10O17:Eu2+was discussed by theory of charge balance, and the influence of Eu2+sites in BaMgAl10O17:Eu2+on the photoluminescence and thermal properties were discussed in detailed.2. The crystal structure of BaMgAl10O17was carefully discussed, and the formation of lattice defects was also discussed, the band structure was calculated by computer simulation via Castep; considering the lower electronegativity elements can improve the the stability properties of conduction layer, the influence of doped S such as its ion radius and electronegativity on the photoluminescence and thermal properties were discussed; the influence of doped Si3N4on the photoluminescence and thermal properties were discussed based on its ion radius and electronegativity, and the energy transfer between Eu2+and Mn2+was also discussed. 3. Nano meter blue phosphor BaMgAl10O17:Eu2+was synthesized via sol-gel method, its growth process was investigated by change the burning temperature, reaction time and heating rate etc; the difference of photoluminescence between nano and bulk BaMgAl10O17:Eu2+phosphor under254nm and147nm excitation were evaluated, and the influence of defects on the photoluminescence and thermal properties were investigated, its potential application in3D-PDP was also evaluated.4. The crystal structure of BaAl12O19and the formation of lattice defects were studied; S and Si3N4were introduced in to BaAl12O19:0.1Mn2+, considering the lower electronegativity elements can improve the the stability properties of conduction layer, the change of photoluminescence properties and decay time were investigated based on the ion radius and electronegativity of S and Si3N4, the influence of defects in the energy transfer also investigated.These works indicated that defect play an important role in the thermal degradation of BaMgAl10O17:Eu2+; S and Si-N doped BaMgAl10O17:Eu2+and BaAl12O19:0.1Mn2+exhibits better intensity, good thermal stability and shorter decay time respectively, which have potential application in mercury free fluorescent lamp or3D-PDP; the cubic like sharp BaMgAl10O17:Eu2+phosphor also have potential application in3D-PDP.