鑭系元素摻雜之奈米晶體的合成分析與近紅外光驅動上轉換能力之研究

Synthesis and characterization of near-infrared light triggered lanthanide-doped upconversion nanocrystals

徐憶瑄(Yi-Husan Hsu)

指導教授 ： 陳建宏

中山醫學大學/健康管理學院/應用化學系碩士班/碩士(2015年)

https://doi.org/10.6834/CSMU.2015.00048

摘要

本研究主要在於製備氟化物摻雜Yb3+、Tm3+ 離子的上轉換奈米粒子 (upconversion nanoparticles，UCNPs)，並探討摻雜活化劑 Tm(CH3CO2)3及鹼類當量數的增加對於上轉換發光強度的影響。
實驗一開始想利用低溫高壓的方式合成UCNPs而使用了高壓反應釜。從TEM中的分析中得知，雖然部分粒徑達到預期的大小，但是TEM圖所呈現的粒子呈不規則形狀(AC7、AC14)，且在980 nm的雷射激發下並沒有上轉換的效果。之後的合成加熱方式我們捨棄了高壓反應釜，改使用加熱包直接在氬氣下加熱，成功合成出粒徑小於100 nm且具有上轉換效果的NaYF4/LiYF4:Yb、Tm。
為了更一步探討UCNPs的組成濃度與上轉換效能之間的關係，並且找出最適合條件，我們將活化劑的量提高到比原本文獻的兩倍當量數，發現增加兩倍活化劑並無法提升上轉換效能，但增加LiOH/NaOH的當量數條件下發現上轉換效能的增強。另外在文獻中提到可以利用包覆核的方式增加上轉換效能，但我們以文獻相同方法合成出的粒子在TEM下並沒有核包覆的現象，而是外觀從多角形變成了棒狀。此奈米棒具有較佳的上轉換效能，計算奈米棒的長寬比aspect ratio(AR) L1S(AR=3.9)>L3S(AR=3.77)、N3S(AR=3.73)>N1S(AR=2.64)，發現AR值越高者上轉換效率越高。

關鍵字

上轉換 ； 鑭系金屬 ； 980 nm近紅外光

並列摘要

This study mainly discusses the synthesis of NaYF4/LiYF4 nanoparticles containing Tm3+/Yb3+. The upconversion efficiency of these nanoparticles correlated to the equivalent of activator or base during the syntheses is also demonstrated. The TEM images of the particles prepared by autoclave under lower temperature show that most of the particles are irregular (AC7 and AC14). In the meantime, the particles could not show the upconversion efficiency under 980 nm excitation. In order to improve the diameter and the upconversion efficiency of the nanoparticles, we used the heating mantle for the synthesis of the nanoparticles. The nanoparticles with upconversion efficiency and diameter less than 100nm are successfully synthesized. To study the relationship between the equivalent of the activator / base and the upconversion efficiency of the nanoparticles, we increased the equivalent of the activator. The result indicated that the upconversion efficiency was not enhanced by increasing the equivalent of the activator. However, the increasing the equivalent of the base ( LiOH / NaOH) during the synthesis resulted in the enhanced upconversion efficiency of the nanoparticles. The further addition of Y(CH3CO2)3 and base (LiOH / NaOH) to the synthesized NaYF4/LiYF4:Yb,Tm nanoparticles by the heating mantle led to the formation of new nanoparticles. The TEM images of the nanoparticles show that the shapes of the nanoparticles transformed from hexagon to rod (L1S、L3S、N1S、N3S). The analysis of the length-to-width (aspect ratio, AR) of the rod (L1S (AR=3.90), L3S (AR= 3.77); N3S (AR=3.73), N1S (AR=2.64)) showed that the rod with the higher AR value exhibited the effective upconversion efficiency.

並列關鍵字

upconversion efficiency ； luminescent materials ； infrared light

參考文獻

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