奈米銀粒子/氧化鋅奈米柱複合材料之製備方法與其光學特性探討

Optical properties of silver nanoparticles with zinc oxide hybrid nanostructure produced by electric current heating process

侯順淵(Shun-Yuan Hou)

指導教授 ： 湯茂竹 ； 李志浩

國立清華大學/原子科學院/先進光源科技學位學程/碩士(2020年)

摘要

氧化鋅(ZnO)的特殊光學特性，使其成為紫外光半導體光源或感測器的重要材料，如何調整其發光特性更是重要的研究課題之一。科學家已經發現當氧化鋅與電漿子金屬奈米粒子產生連結時，會大幅地改變其自身的光學表現，本論文將探討奈米銀粒子/氧化鋅奈米柱複合材料新的製程架構，發展兩種不同的製程方法，第一種是利用微小結構或原子分子間凡德瓦力的吸附，讓10 ppm銀奈米粒子溶液滴附在氧化鋅上達成連結，另一種方法則是先在氧化鋅奈米柱上濺鍍一層銀薄膜，並於矽基板上通入電流5安培，此舉會燒熔氧化鋅上的銀膜，使得銀膜因為固態去濕(Solid state dewetting)效應而在表面產生島膜與奈米粒子的附著。
分別對這兩種合成方式製作出的複合材料，量測其光致發光光譜(Photoluminescence, PL)，量測結果發現在近帶邊緣(near band edge, NBE)的激發光波段，使用凡德瓦力吸附製程的複合材料，隨著滴附時間的增加，強度呈現下降趨勢，而利用電流燒熔製程的複合材料，在特定的銀薄膜厚度下進行燒熔後會產生大幅的近帶邊緣激發光強度的提升。本論文也花了很大的篇幅於電流燒熔製程的參數調控，在一連串的實驗測試，最終成功使此製程能夠簡單快速的產生奈米複合材料，並能穩定提升氧化鋅的本質激發光強度，最多有2.8倍的強度增幅。
由於電流燒熔製程的樣品有較好的激發光強度增幅，我們針對材料進行了材料特性的分析，使用同步輻射中心台灣光子源23A奈米探測(X-ray Nanoprobe)光束線的X光技術，來檢測複合材料在不同製程條件下的化學狀態，此外也使用清大工科系的X光繞射儀檢測在製程過程中複合材料晶向的穩定度，也於清大醫工系進行UV-Vis光譜量測，則是觀察銀奈米粒子所貢獻的異常吸收波段，說明銀奈米粒子會造成表面電漿共振的效應，證實所嘗試的製程架構可以成功製造氧化鋅/銀奈米複合物並有效地提高其激發光強度。

關鍵字

表面電漿共振 ； 同步輻射 ； 銀奈米粒子 ； 氧化鋅奈米柱 ； 光致發光

並列摘要

The optical properties of zinc oxide have made it an important material for ultraviolet semiconductor light sources. Adjusting its luminous properties is one of the important issues. It has been found that when zinc oxide is connected with plasmonic nano particles, it would change its optical performance. In order to discuss the changing behavior under different connection conditions, this thesis mainly proposes new process architecture for ZnO/Ag hybrid-structure. There are two new process methods, one is to use the adsorption of van der Waals between the 10 ppm silver nanoparticle solution to be achieved the connection. The other is to sputter a layer of silver film on zinc oxide and under the current of 5A. It would make the silver film to adhere to nano particles on the surface due to the solid state dewetting effect.
Use these two way to form the sample and do the photoluminescence analysis. The sample used the method_1 to make show the PL result keep decay with the attached time increased. Method_2 sintered the sample with a current, the intensity of the near-band edge light is greatly increased.
Finally, because the method_2 sample has the phenomenon of increasing the light intensity. The material characteristics were also analyzed with the X-ray technology. X-ray absorption spectrum is for the chemical state. XEOL spectrum is for the deep luminous properties of the material. X-ray diffraction is for the stability of the crystal orientation. The material is finally analyzed by UV-Vis spectroscopy. The results showed obvious abnormal absorption bands. It was successfully confirmed that the proposed process architecture to manufacture of zinc oxide / silver nano composites.

並列關鍵字

Localized surface plasmon resonance ； Synchrotron radiation ； Silver nanoparticle ； ZnO nanorods ； Photoluminescence

參考文獻

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