藍光螢光粉劣化與螢光粉塗料之研究

Abstract

PDP藍光螢光粉(BaMgAl10O17:Eu2+)在商業上廣泛使用，具有高亮度特性，但是由於其結構不穩定與發光中心易氧化等緣故使的藍光螢光粉容易因為受熱與使用中受VUV光照射而有明顯老化的問題，本論文就是利用一些方法像包覆Al2O3 及螢光層網印製程改變熱處理條件來阻止螢光粉因為製程的過程受熱，或是受VUV光照射時的傷害，同時也因為包覆Al2O3修補螢光粉表面缺陷再加上適當溫度的退火，使螢光粉亮度有小幅的提升，我們進一步更結合了Al2O3包覆及螢光層脫脂熱處理簡化成一步製程，使螢光粉可以在脫脂過程也一起包覆Al2O3保護層，另外，我們經由減慢熱處理速度的的方式可以低溫脫脂也增加螢光層堆積密度進而提升發光效率，適合在面板製程中應用,使點亮的亮度壽命更提升。

Blue phosphor BaMgAl10O17 (BAM) activated by divalent europium ions Eu2+ which is widely use as the blue-light-emitting commercial phosphor for PDPs This phosphor is well adapted for its used in PDPs because of its high quantum efficiency (around 80%), its good chromaticity. On the other hand the stability of BAM is not good. Its luminous efficiency decreases during the panel manufacture [due to heat] and also during the operation of the panel [due to VUV light]. In this study,we use coating Al2O3 film on blue phosphor to protect it from degradation. To study the change of thermal stability and longevity of BaMgAl10O17 :Eu2+ phosphor, we investigated the effects of the nano and continuous coating of Al2O3 on the surface of BaMgAl10O17 :Eu2+ phosphor as a protective layer.Al2O3 was used as the coating material because it has a wide bandgap and exhibits minimal losses in VUV penetration. Therefore, it is the aim of this paper to present optical and morphological analysis of nano and continuous coating of Al2O3 , which increases the thermal stability or longevity of the phosphors by encapsulating the phosphor particles. Moreover, we combine nano coating with phosphor slurry debinding,so we can get a protective Al2O3 layer when we burn-out binder from the phosphor slurry. Furthermore, we slow down the debinder velocity .By this way ,we can debinder in lower temperature and increase the packing density to improve PL efficiency.