以溶膠-凝膠法製備Eu, Gd, Dy三摻雜鋁酸鍶螢光粉及其光致發光特性研究

本研究是以溶膠-凝膠法製備合成 SrAl2O4之螢光粉體，並摻雜活化劑 Eu 及共摻雜 Eu-Gd 與三摻雜 Eu-Gd-Dy，研究於不同摻雜濃度及煆燒溫度下對粉體之結構特性及性質影響。研究分析包括，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)等材料分析及紫外-可見光譜(UV-Vis)和螢光光譜分析(PL)等光學特性分析來探討其結構及光學性質。 XRD 結果顯示，以溶膠-凝膠法可在 900℃煆燒下合成 JCPDS 卡號 NO. 34-0379 單斜晶系之 SrAl2O4 主體，且在 1100℃煆燒下結晶性有所提升，當共摻雜 Eu-Gd 離子於 1100℃煆燒下，Gd 離子濃度提升至 3%時會導致 GdSrAl3O7與 Sr4Al14O25相出現，在三摻雜 Eu-Gd-Dy 離子時，當 Dy 離子摻入導致 Sr3Al2O6、SrAl4O7 及 Sr4Al14O25 相出現。SEM 結果顯示，當摻雜 Eu、Gd 及 Dy 離子時，對 SrAl2O4主體形貌沒有影響，皆為顆粒相互連接成大小不一的長條棒狀。TEM 結果顯示，晶粒形貌與 SEM 分析結果相同，為晶粒相互連接成長條狀之形貌，經繞射點與高解析圖皆能證實為 SrAl2O4主體，但共摻雜 1%Eu-7%Gd 於 1100 ℃煆燒下之樣本，表明在高溫煆燒與摻雜濃度增加，而導致二相 GdSrAl3O7出現。PL 結果顯示，共摻雜 Eu-Gd 之樣本以 Eu3+最佳激發波長 259 nm 為激發波長，可得 612 nm 具有最佳放射峰，屬於 Eu3+離子 5 D0→7 F2 之電偶極躍遷，於共摻雜 1%Eu-7%Gd 於 1100 ℃煆燒下放射強度最佳，並繪製 CIE II 色度座標圖，顯示在紫紅色發光區域。另外，三摻雜 Eu-Gd-Dy 之樣本以 259 nm 為激發波長，在三摻雜 1%Eu-1%Gd-1%Dy 於 900 ℃煆燒下，位於 612 nm 有較佳之放射峰，繪製 CIE 色度座標圖，顯示在紫色發光區域。

關鍵字

SrAl2O4 ；銪摻雜；螢光粉；三摻雜；溶膠-凝膠法

並列摘要

In this study, the phosphor powder of SrAl2O4 was prepared by sol-gel method, and doped with activator Eu and co-doped Eu-Gd and triple-doped Eu Gd-Dy. The influence of temperature on the structural characteristics and properties of the powder. Research analysis includes X-Ray diffraction analysis (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and other material analysis, as well as ultraviolet-visible spectroscopy (UV-Vis) and fluorescence spectroscopy (PL) and other optical characteristics analysis to explore its structure and optical properties. The XRD results show that the sol-gel method can be used to synthesize the monoclinic SrAl2O4 main phase with JCPDS card number NO. 34-0379 through calcination at 900℃. The crystallinity improves further when calcined at 1100℃. When co-doped with Eu and Gd ions, an increase in Gd ion concentration up to 3% leads to the appearance of GdSrAl3O7 and Sr4Al14O25 phases. Additionally, when co-doped with Eu, Gd, and Dy ions, the introduction of Dy ions results in the appearance of Sr3Al2O6, SrAl4O7, and Sr4Al14O25 phases. SEM analysis shows that the morphology of the SrAl2O4 main phase remains unaffected when doped with Eu, Gd, and Dy ions, with particles interconnected to form elongated rod-like structures of varying sizes. TEM analysis confirms the grain morphology observed in SEM, with grains interconnected to form elongated structures. Diffraction patterns and high resolution images verify the presence of the SrAl2O4 main phase. However, in the sample co-doped with 1% Eu and 7% Gd and calcined at 1100℃, the IV appearance of the GdSrAl3O7 phase indicates the influence of high-temperature calcination and increased doping concentration. PL analysis reveals that the sample co-doped with Eu and Gd exhibits optimal emission at 612 nm when excited at the preferred excitation wavelength of 259 nm. This emission corresponds to the electric-dipole transition of Eu3+ ions from the 5 D0 to 7 F2 state. The sample co-doped with 1% Eu and 7% Gd and calcined at 1100℃ shows the highest emission intensity, and the CIE color coordinates plot indicates emission in the purplish-red region. On the other hand, the sample co doped with Eu, Gd, and Dy exhibits better emission at 612 nm when excited at 259 nm, in the case of 1% Eu, 1% Gd, and 1% Dy co-doping and calcination at 900℃. However, the triple-doped Eu-Gd-Dy sample has a better emission peak at 612 nm when the triple-doped 1%Eu-1%Gd-1%Dy is fired at 900 °C with an excitation wavelength of 259 nm. Plot the CIE chromaticity coordinates diagram, shown in the purple glow area.