以溶膠-凝膠法製備LaAlO3 : M ( M = Ce, Eu ) 螢光粉之光致發光特性研究

發光材料大部分是藉由內部原子占據主體晶格之位置導致能量放射進而產生光，故螢光粉於材料的選擇上非常重要，而鋁酸鑭(LaAlO3)為一較新穎之材料，其具有良好的化學穩定性、機械耐久性及光學活性等特性，在近幾年來成為了發光材料研究重點之一。本實驗製備樣品粉末之方法為溶膠-凝膠法，以三嵌段兩性共聚物F-127做為螯合劑，再分別以硝酸鋁、硝酸鑭及硝酸鈰做為LaAlO3及摻雜元素Ce離子、Eu離子之前驅物，經製程溫度850℃、900℃煆燒後獲得LaAlO3樣品粉末，最後經由X-Ray繞射分析(XRD)、掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)和發光性質量測(PL)等材料分析來探討其結構及性質。由XRD分析結果得知利用溶膠-凝膠法於900℃煆燒之效果較佳，未摻雜之LaAlO3晶粒大小約為30.24 nm，屬於三方晶系中之菱面體。且摻雜濃度過多時，其晶粒卻稍微大於純LaAlO3樣本，推測其原因為此濃度之稀土離子的摻雜量太多以其他的形式存在於晶格外，因此主體晶體之晶粒成長沒受到抑制。由CIE分析結果得知LaAlO3摻雜Ce皆在藍色區域發光；LaAlO3摻雜Eu皆在紅色區域發光。

關鍵字

鋁酸鑭；鈰摻雜；銪摻雜；光致發光

並列摘要

Most of the luminescent materials are caused by the internal atoms occupying the position of the host lattice to cause energy emission to generate light. Therefore, the selection of phosphors is very important. LaAlO3 is a relatively new material. Good chemical stability, mechanical durability, optical activity and other characteristics have become one of the research focus of light-emitting materials in recent years. LaAlO3, Ce-doped LaAlO3 and Eu-doped LaAlO3 were prepared by sol-gol process with a triblock copolymer F-127 as a chelating agent, and aluminum nitrate, lanthanum nitrate, cerium nitrate and europium nitrate as precursors. The as-synthesized products then calcined at 850℃ and 900℃. X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL) were used to characterize the microstructure and properties of the samples. According to the XRD analysis results, it is known that the sol-gel method is better at 900℃, and the undoped LaAlO3 grain size is about 30.24 nm, which belongs to the rhombohedron in the trigonal system. When the addition of dopant was too much, the crystal grains was exist in other form outside the crystal lattice, so the grain growth of the main crystal is not suppressed. From the CIE analysis results, it is know that Ce-doped LaAlO3 emits light in the blue region and Eu-doped LaAlO3 emits light in the red region.