LnVO4(Ln = In, La)共摻Pr, Bi之光致發光特性研究

Synthesis and Photoluminescence Properties of Pr and Bi co-doped LnVO4(Ln = In, La) Phosphors

魏立凱(Li-Kai Wei)

指導教授 ： 張益新

國立虎尾科技大學/電機資訊學院/電子工程系碩士班/碩士(2015年)

https://doi.org/10.6827/NFU.2015.00111

摘要

本研究係以溶膠-凝膠法(sol-gel method)製備螢光粉，第一部分為以InVO4作為螢光粉主體，摻雜不同Pr3+離子濃度，藉由共摻La3+離子取代In3+離子之位置改善其螢光粉體之發光特性。第二部分則以LaVO4作為螢光粉主體，摻雜不同濃度Pr3+離子，共摻Bi3+離子探討其摻雜濃度對晶體結構與發光特性之影響。
第一部分，由XRD結果顯示，在煆燒950℃持溫6小時條件下，可得知結構為斜方晶系InVO4之結晶結構。Pr3+離子摻雜濃度從0.5 mol%增加至10 mol%，當摻雜濃度到達3 mol%並無雜相的產生。之後固定Pr3+離子3 mol%之摻雜量，以La3+離子取代In3+離子之位置，隨著La3+摻雜濃度的增加，螢光粉體之結晶結構由斜方晶系之InVO4結構轉變為單斜晶系之LaVO4結構。從SEM分析得知，(In1-xPrx)VO4螢光粉體的表面型態並不會因為Pr3+離子摻雜濃度的多寡而有太大的改變，但隨著La3+摻雜濃度的增加，螢光粉體之顆粒尺寸有細化的趨勢。在315 nm激發下，其放射光譜並未觀察到Pr3+離子的特性躍遷放射，以326 nm激發下，放射光譜的強度較強，顯示出InVO4:Pr3+螢光粉體其放射主要來自於InVO4主體所產生的放射，其CIE色度座標座落於黃綠光的位置。隨著La3+摻雜濃度的增加，其放射光譜逐漸顯示出Pr3+離子的特性躍遷放射，其放射光譜由Pr3+離子的3P0→3H4,5,6、1D2→3H4和3P0→3F2電子躍遷所構成。其CIE色度座標由黃綠光偏移至近白光之位置。
而在第二部分，由XRD分析結果顯示，在煆燒950℃持溫6小時條件下，可得知結構為單斜晶系LaVO4之結晶結構。隨著Pr3+離子摻雜濃度的增加，並沒有觀察到二次相的產生。SEM分析方面，螢光粉體的表面型態並不會因為Pr3+離子摻雜濃度的多寡而有所改變。在315nm激發下，其放射光譜由Pr3+離子的3P0→3H4,5,6、1D2→3H4和3P0→3F2電子躍遷所構成。在低濃度的Pr3+離子摻雜時，590 ~ 630 nm範圍的1D2→3H4躍遷放射峰強度較強，使得此螢光粉體藉由摻雜不同濃度的Pr3+離子，其CIE色度座標由橙紅色偏移至近白光，再偏移至綠光的位置。在Bi3+離子的共摻下可發現，螢光粉體的發光強度有明顯的提升，可說明Bi3+離子有發揮其增感劑之作用。

關鍵詞: 溶膠-凝膠法、Pr3+離子、增感劑、螢光粉

關鍵字

溶膠-凝膠法 ； Pr3+離子 ； 增感劑 ； 螢光粉

並列摘要

In this study, the phosphor was prepared by a sol-gel method. The first part InVO4 was selected as the host material, doped with different Pr3+ ions concentrations, In3+ ions replaced by co-doped with La3+ ions to improve phosphors luminescence properties. The second part LaVO4 was selected as the host material, doped with different Pr3+ ions concentrations, co-doped with Bi3+ ions. The crystal structure, surface morphologies, and photoluminescence properties of the La1-x-yPrxBiyVO4 phosphors were then investigated.
First, the XRD results shows that the crystal structure of In1-xPrxVO4 phosphor calcined at 950℃ for 6 hr can be attributed to the orthorhombic structure for InVO4. There are no extraneous phases appear when the Pr3+ ions concentrations increase to 3 mol%. When the In3+ ions replaced gradually by the La3+ ions, the crystal structure of the phosphor changes from orthorhombic InVO4 structure to monoclinic LaVO4 structure. The SEM results show that there are no obvious differences for surface morphology of In1-xPrxVO4 phosphors. However, the particles become smaller when the La3+ ion is increased. Under an excitation of 315 nm, there are no electron transition of the Pr3+ ion appear in the emission spectra. But the emission intensity is stronger, shows that In1-xPrxVO4 phosphors emission mainly comes from the host InVO4 by 326 nm exciting, and which has a CIE chromaticity coordinates locating in the yellowish-green region. With La3+ ions concentrations increasing, the emission gradually shows the electron transition of the Pr3+ ion, corresponding to the 3P0→3H4,5,6、1D2→3H4and 3P0→3F2. The CIE chromaticity coordinates shift to the white light region from yellowish-green region.
Second, the XRD results shows that the crystal structure of La1-xPrxVO4 phosphor calcined at 950℃ for 6 hr can be attributed to the monoclinic structure for LaVO4. There are no secondary phases exist when the Pr3+ ions concentration increased. The SEM results show that there are no obvious differences for surface morphologies of La1-xPrxVO4 phosphors. By 315 nm exciting, the emission spectra show some emission bands corresponding to the 3P0→3H4,5,6、1D2→3H4and 3P0→3F2 electron transition of the Pr3+ ion. The CIE chromaticity coordinates from orange-red shift to white light region and then shift to green light region. The emission intensities were enhanced for with Bi3+ ion doped La1-xPrxVO4 phosphor, indicating that the Bi3+ ions can act as a sensitizer in the La1-xPrxVO4 phosphor.

Keywords: sol-gel method, Pr3+ ion, sensitizer, phosphor

並列關鍵字

sol-gel method ； Pr3+ ion ； sensitizer ； phosphor

參考文獻

[60] 張祐嘉，民國102年，“(Y1-x-yPrxLay)InGe2O7 (x=0~0.2, y=0~0.2)系之光致發光特性研究”，國立虎尾科技大學電子工程研究所碩士論文。

[4] W. T. Hsu, W. H. Wu, C. H. Lu, 2003, “Synthesis and luminescence properties of nano - sized Y3Al5O12：Eu3+ phosphor ”, Mater. Sci. Eng. B, 104, 40-44.

[5] S. D. Han, S. P. Khatkar, V. B. Taxak, G. Sharma, D. Kumar, 2006, “Synthesis, luminescence and effect heat treatment on the properties of Dy3+-doped YVO4phospoh”, Mater. Sci. Eng. B, 129, 126.

[6] Y. C. Li, Y. H. Li, Y. F. Lin, Y. S. Chang, Y. J. Lin, 2007, “Synthesis and luminescent properties of Ln3+( Eu3+, Sm3+, Dy3+)-doped lanthanum aluminum germinate LaAlGe2O7 phosphor”, J. Alloy. Compd. 439, 367.

[7] 項鈺軒，民國100年，“以溶膠-凝膠法製備BaY2-xLaxZnO5:Eu3+ (x=0~0.36)螢光粉及其光致發光性質研究”，國立虎尾科技大學光電與材料科技研究所碩士論文。