氧化金薄膜之還原現象於侷域性表面電漿共振應用之研究
Other Title
Localized Surface Plasmonic Resonance Phenomena in Reduced Gold Oxide Films
Journal
國家奈米元件實驗室奈米通訊
Journal Volume
21
Journal Issue
4
Start Page
20
End Page
28
ISSN
1029-502x
Date Issued
2014-12
Author(s)
Abstract
於本研究中，我們利用反應性濺鍍方法製作大面積且均勻的氧化金薄膜，而後於常溫常壓下放置使其還原而形成金奈米粒子包覆在氧化金薄膜結構。於材料特性分析上，我們利用多種材料與光學分析方法來研究此氧化金薄膜之性質，透過光學分析來得到氧化金於玻璃基板或矽基板上之光學常數。此外，我們亦觀察到所製備的氧化金薄膜於還原的過程中將會產生侷域性之表面電漿共振現象，其共振的波段可由可見光調控至近紅外光波段；而此現象不同於一般化學合成法所合成出之金奈米粒子，我們觀察到於存放不同時間後之氧化金薄膜，其侷域性表面電漿共振波段可由700奈米大幅的變化到980奈米。於本研究中，我們亦利用此種還原氧化金薄膜作為表面增強拉曼散射之基板，對於R6G分子我們可以偵測到10^(-10)M的濃度，相較於一般表面增強拉曼散射基板之偵測極限並不會相差太多。因此，於本研究中所提出之快速且大面積製作氧化金薄膜之方法，將可應用於可調控共振波長之表面增強拉曼散射基板於光學與化學上之感測。
In this study, we used reactive sputtering to prepare large-area, homogeneous gold oxide (AuO_x) films, which we then subjected to reduction processes under ambient conditions at room temperature to obtain reduced AuO_x films featuring embedded Au nanoparticles (NPs). We analyzed these films in terms of both their material characteristics and optical properties. For the first time, we obtained the optical constants of AuO_x films directly deposited on glass and Si substrates. Moreover, we observed localized surface plasmon resonance (LSPR) phenomena from the visible to the near-infrared (NIR) during the formation of the Au NPs in the AuO_x film. The plasmonic properties of the Au NPs embedded in the AuO_x films were much different from those of chemically synthesized Au NPs. We found that the LSPR wavelength of the Au NPs embedded in the AuO_x films could be tuned from 700 to 980 nm by varying the duration of the reduction process. Moreover, the reduced AuO_x films could be applied as surface-enhanced Raman spectroscopy (SERS)-active substrates. The minimum detection was achieved down to a concentration of 10^(-10)M (R6G) when using the reduced AuO_x !lm-based substrate-a level comparable with those of other kinds of SERS substrates prepared using more complicated methods. The rapid method proposed herein provides large-area films with tunable resonance wavelengths for applications as SERS-active substrates in optical and chemical sensing.
Subjects
氧化金薄膜
還原過程
侷域性表面電漿共振現象
表面增強拉曼散射
金奈米粒子
近紅外光波段
Gold oxide (AuOx) Film
Reduced Procedure
Localized Surface Plasmon Resonance(LSPR)
Surface Enhanced Raman Scattering
Au Nanoparticles
Near Infrared-ray Regime
Type
journal article