使用陽極氧化鋁基板探討表面電漿子增強型拉曼及螢光光譜

Abstract

原子層沉積技術是一種能夠精準控制材料成長厚度和成分的技術，而陽極氧化鋁能夠大面積且低成本的製造出緊密六角排列的奈米孔洞結構，也可透過控制陽極處理電壓或溫度控制孔洞的直徑和分布，結合這兩者的優點將非常適合用以製作表面電漿子增強型拉曼和螢光基板，本研究將研究溫度和陽極處理電壓對陽極氧化鋁孔洞大小和分布的影響，並使用原子層沉積技術成長的氧化鋁縮小孔洞，探討奈米孔洞大小對表面電漿子增強型拉曼和螢光的影響為何。 本研究先熱蒸鍍金屬銀在陽極氧化鋁奈米孔洞上，做出表面電漿子增強型拉曼基板，並使用原子層沉積技術精準控制二氧化鈦極薄膜的厚度，測量出2nm二氧化鈦極薄膜的拉曼訊號；接著使用原子層沉積技術成長不同厚度(25cycles、50cycles、100cycles)的氧化鋁以縮小孔洞，之後做成表面電漿子增強型拉曼基板並測量二氧化鈦拉曼訊號，發現成長50cycles氧化鋁的基板具有最強的增強效果。本研究也延續上述的結構，將待測物改為氧化鋅並測量其光致發光訊號，同樣發現縮小50cycles氧化鋁之基板具有最強的光致發光訊號。

Atomic layer deposition (ALD) is an excellent deposition technique that controls the film’s thickness in the monolayer precision. Hexgonal pore arrays can be produced by anodic aluminum oxide(AAO) in a long range area and with an inexpensive electrochemical anodization process. Combining the two techniques above, one can fabricate the substrates for surface-enhanced raman scattering(SERS) and surface-enhanced luminescence(SEL). In this research, how the anodization voltage and temperature affect the pore size and distribution is discussed. We also study the relationship between the pore size and the intensity of SERS and SEL. In this research, we evaporate 40nm Ag onto AAO as a SERS substrate and use ALD to deposit TiO2 ultrathin film. The detection of 2nm TiO2 raman scattering is achieved. In order to investigate the relationship between the pore size and the SERS intensity, we use ALD to deposit Al2O3 (25cycles、50cycles、100cycles) and reduce the pore size. The greatest enhancement of raman scattering signal is found with 50cycles deposition of Al2O3. Following with the structure above, we substitute TiO2 with ZnO and measure the photoluminescence spectrum. The greatest enhancement of photoluminescence is also with 50cycles Al2O3.