CREOL, The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816, United States.
ACS Nano. 2012 Jul 24;6(7):6301-7. doi: 10.1021/nn301742p. Epub 2012 Jun 29.
Voltage controlled wavelength tuning of the localized surface plasmon resonance of gold nanoparticles on an aluminum film is demonstrated in single particle microscopy and spectroscopy measurements. Anodization of the Al film after nanoparticle deposition forms an aluminum oxide spacer layer between the gold particles and the Al film, modifying the particle-substrate interaction. Darkfield microscopy reveals ring-shaped scattering images from individual Au nanoparticles, indicative of plasmon resonances with a dipole moment normal to the substrate. Single particle scattering spectra show narrow plasmon resonances that can be tuned from ~580 to ~550 nm as the anodization voltage increases to 12 V. All observed experimental trends could be reproduced in numerical simulations. The presented approach could be used as a general postfabrication resonance optimization step of plasmonic nanoantennas and devices.
在单粒子显微镜和光谱测量中，证明了金纳米粒子在铝膜上的局域表面等离子体共振的电压控制波长调谐。在纳米粒子沉积后对 Al 膜进行阳极氧化，在金粒子和 Al 膜之间形成氧化铝间隔层，从而改变了粒子-衬底的相互作用。暗场显微镜显示出单个 Au 纳米粒子的环形散射图像，表明存在与衬底垂直的偶极矩的等离子体共振。单粒子散射光谱显示，随着阳极氧化电压增加到 12 V，等离子体共振可以从580nm 调谐到550nm，窄的等离子体共振。所有观察到的实验趋势都可以在数值模拟中重现。所提出的方法可以用作等离子体纳米天线和器件的一般后制造共振优化步骤。
