Correlated Rayleigh Scattering Spectroscopy and Scanning Electron Microscopy Studies of Au-Ag Bimetallic Nanoboxes and Nanocages

详细信息    查看全文

• 作者：Min Hu ; Jingyi Chen ; Manuel Marquez ; Younan Xia ; Gregory V. Hartland
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：August 30, 2007
• 年：2007
• 卷：111
• 期：34
• 页码：12558 - 12565
• 全文大小：433K
• 年卷期：v.111,no.34(August 30, 2007)
• ISSN：1932-7455

文摘

The optical properties of hollow nanoparticles (Au-Ag nanoboxes and nanocages) were investigated byrecording Rayleigh scattering spectra of single particles, whose morphology and composition had been analyzedby scanning electron microscopy (SEM). This was achieved by depositing the particles on optically transparentsubstrates with registration marks, which are compatible with SEM imaging. Fitting the experimental spectrato a Lorentzian function yields the frequencies and homogeneous line widths of the plasmon resonance forthe particles. The resonances are extremely broad, with dephasing times of 2-5 fs. Analysis of the line widthdata using the dimensions determined by SEM shows that the broadening is due to a combination of electron-surface scattering and radiation damping. The sensitivity of the plasmon resonance to the dielectric constantof the environment was also investigated by adding a drop of water to the substrate. The nanoboxes showsimilar dielectric sensitivities compared to other metal nanoparticle systems. A significant increase in the linewidth was also observed for the nanoboxes in water compared with air. This was attributed to increasedradiation damping in the environment with a higher dielectric constant. Both the red shift and the increase inline width are reversible.