新穎無機矽酸鹽與磷酸鹽螢光體之發光特性與能量傳遞之研究

Abstract

本研究以固態合成法於氫氣氣氛中分別成功製備Ce3+/Eu2+共摻、Ce3+/Tb3+共摻與Eu2+/Mn2+共摻等多種矽酸鹽及磷酸鹽螢光體，並以X光粉末繞射、螢光光譜、螢光衰變、CIE色度座標，進行螢光體結構、發光特性及色度學分析鑑定，並探討其能量傳遞機制和相關臨界距離，並將所製備之部分螢光體應用於白光LED之封裝。 第一部分探討Ce3+/Eu2+共摻Ba4La6O(SiO4)6中能量傳遞的機制，其中Ce3+為敏化劑而Eu2+為活化劑，隨著Eu2+摻雜濃度增加，Eu2+放光強度也隨之增加，而Ce3+放光強度則隨之減弱。第二部分探討Ce3+/Tb3+分別共摻Ba4La6O(SiO4)6、LiLa9(SiO4)6O2及Ba2Sr(PO4)2等三種螢光體能量傳遞的機制，並藉由不同Ce3+/Tb3+共摻比例調控其顏色，可由藍紫光變為藍綠光最後變為綠光。第三部分則探討Eu2+/Mn2+共摻Ba2Ca(PO4)2中能量傳遞的機制，藉由能量傳遞增強Mn2+發光之強度。 經色度量測顯示上述螢光粉分別發射藍光、藍綠光、綠光及紅光等色光，預期將可提供紫外白光發光二極體應用的新選擇，本論文中部分螢光體具有照明應用的潛力。

In this study, Ba4La6O(SiO4)6:Ce3+,Eu2+, Ba4La6O(SiO4)6:Ce3+,Tb3+, LiLa9(SiO4)6O2:Ce3+,Tb3+,Ba2Sr(PO4)2:Ce3+,Tb3+, Ba2Ca(PO4)2:Eu2+,Mn2+ were synthesized by solid state method.The structure,luminescence and chromaticity properties and quantum efficiency of phosphors were characterized by X-ray powder diffraction, fluorescence spectroscopy. Additionally, the emission color can be further tuned by co-doping with Eu2+ or Tb3+ or Mn2+. Furthermore, We investigated the mechanism of energy transfer and critical distance in these silicate and phosphate phosphors. Finally,we dicussed the fabrication of white LED divices that using the phosphor of Ba2Ca(PO4)2:Eu2+,Mn2+.The results show that Ba2Ca(PO4)2:Eu2+,Mn2+ can be a promising phosphor for white LED with CCT of 5898k, CRI of 88,and CQS of 92.