(Y_(1-X)Tb_X)_3Al_5O_(12)完全固溶體合成、結構及其發光特性之研究

本實驗利用固態反應法合成不同含量Tb^(3+)離子摻雜的YAG-TAG螢光粉體，對合成過程所帶來結構與螢光性質改變做相關研究。由SEM顯示，可看到隨著Tb^(3+)含量增加，晶型愈完整、顆粒愈大與結晶度愈高，經過第二階段煅燒（1600℃/4 h）後，純TAG粉體平均顆粒尺寸已達5 μm左右；拉曼光譜數據中，不論低頻或高頻區之波模皆有往低波數（頻率）偏移之趨勢，此足以證實因為Y^(3+)與Tb^(3+)之鍵結差異；隨Tb^(3+)含量愈多，Tb^(3+)之特徵吸收峰強度有變強之趨勢，但是因為伴隨濃度淬滅與主體轉換之效應，因此基本上Tb^(3+)量愈多，YAG:Tb發光強度愈低；且由間接計算發生濃度淬滅時Tb^(3+)間距也證實此效應存在之正當性。

關鍵字

YAG-TAG完全固溶體；濃度淬滅；主體轉換

並列摘要

This research used a solid-state reaction method to synthesize YAG-TAG phosphors doped with varying amount of Tb^(3+). This study focused on analyzing the effect of Tb^(3+) doping on the structure and photoluminescence of the YAG-TAG phosphors. SEM micrographs showed that as the Tb^(3+) content increases, the phosphors grains have more homogeneous morphology, larger grain size and higher crystallinity. After the second calcination at 1600℃ /4 h, the average grain diameter of pure TAG phosphor is 5 μm. Raman spectra showed that the wave mode shifts to lower wave-number region regardless their frequencies. It is resulted from bonding difference between Y^(3t) and Tb^(3t). This absorbance results implied that the absorption intensity of Tb^(3+) characteristic peak increases with increasing Tb^(3+) doping. On the other hand, the YAG:Tb emission intensity decreases with increased Tb^(3+) doping due to concentration quenching and host transition effects. The indirect estimate of Tb^(3+) spacial distances during concentration quenching also affirms the Tb^(3+) doping effect.

並列關鍵字

YAG-TAG complete solid solution ； Concentration quenching ； Host transition

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