(YXTbX)3Al5O12完全固溶体合成结构及其发光特性之研究.DOC

(Y1-XTbX)3Al5O12 完全固溶體合成、結構及其發光特性之研究 Synthesis, Structure and Photoluminescence of (Y1-XTbX)3Al5O12 Complete Solid Solution 李 玄 閔1 ■ 陳 威 宇1 ■ 吳 佳 穎1 ■ 黃 啟 原2 H.M. Lee 1 W.Y. Chen 1 J.Y. Wu 1 C.Y. Huang 2 國立成功大學資源工程學系　1 研究生　2 教授 本實驗利用固態反應法合成不同含量Tb3+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Tb3+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Y3+與Tb3+之鍵結差異；隨Tb3+含量愈多，Tb3+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Tb3+量愈多，YAG:Tb發光強度愈低；且由間接計算發生濃度淬滅時Tb3+間距也證實此效應存在之正當性。 關鍵詞： YAG-TAG 完全固溶體、濃度淬滅、主體轉換 This research used a solid-state reaction method to synthesize YAG-TAG phosphors doped with varying amount of Tb3+. This study focused on analyzing the effect of Tb3+ doping on the structure and photoluminescence of the YAG-TAG phosphors. SEM micrographs showed that as the Tb3+ 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 Y3+ and Tb3+. This absorbance results implied that the absorption intensity of Tb3+ characteristic peak increases with increasing Tb3+ doping. On the other hand, the YAG:Tb emission intensity decreases with increased Tb3+ doping due to concentration quenching and host transition effects. The indirect estimate of Tb3+ special distances during concentration quenching also affirms the Tb3+ doping effect. Key words: YAG -TAG complete solid solution , Concentration quenching, Host transition 壹、前　言 世界能源危機意識逐漸提升，各國均投入大量人力研發新穎之照明設備，而發展具省電、低污染、發熱量低、反應速度快與壽命長等優點之發光二極體 (light emitting diode；LED) 作為光源，已是現代照明之發展趨勢。自 1996 年，日本日亞化學公司 (Nichia) 以藍光晶片 (InGaN) 激發鈰摻雜之釔鋁石榴石 (cerium doped yttrium aluminum garnet；Ce：YAG)之黃色螢光粉而研發白光發光二極體，造就人類照明之一大躍進，亦觸發 LED 邁入照明應用之門檻。 為取得理想照明光源，除 LED 本身亮度外，所選用螢光體