Suppression of Surface-Enhanced Raman Scattering on Gold Nanostructures by Metal Adhesion Layers

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• 作者：Loan Le Thi Ngoc ; Tao Yuan ; Naoto Oonishi ; Jan van Nieuwkasteele ; Albert van den Berg ; Hjalmar Permentier ; Rainer Bischoff ; Edwin T. Carlen
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 25, 2016
• 年：2016
• 卷：120
• 期：33
• 页码：18756-18762
• 全文大小：445K
• 年卷期：0
• ISSN：1932-7455

文摘

We report on the suppression of localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS) of 60 nm thick gold nanostructures by titanium adhesion layers. Significant plasmon damping is observed for titanium layer thicknesses up to t_Ti = 5 nm, which cannot be fully explained by simulation models that account for the overlap of the electric field in the bimetal layer with the titanium layer. Furthermore, the relationship between the SERS enhancement factor and the LSPR quality-factor G ∝ Q⁴ breaks down as t_Ti is increased beyond 1 nm. We attribute the LSPR and SERS suppression to plasmon damping and spectral broadening of interband absorption due to the field overlap with the titanium layer and titanium impurities that interdiffuse through the grain boundaries of the polycrystalline gold layer during the deposition of the Au–Ti bimetal. These observations and analyses serve as a guide for improving the reliability of gold nanoplasmonic sensors.