1306.5230 (Pabitra Das et al.)

Local Electron Beam Excitation and Substrate Effect on the Plasmonic
Response of Single Gold Nanostars    [PDF]

Pabitra Das, Abhitosh Kedia, Pandian Senthil Kumar, Nicolas Large, Tapas Kumar Chini

We performed Cathodoluminescence (CL) spectroscopy and imaging in a high resolution scanning electron microscope to locally and selectively excite and investigate the plasmonic property of a multibranched gold nanostar on silicon substrate. This method allows us to map the local density of optical states from the nanostar with a spatial resolution down to a few nanometers. We resolve both in spatial and spectral domain, different plasmon modes associated with the nanostar. Finite- difference time-domain (FDTD) numerical simulations are performed to support the experimental observations. We investigate the effect of substrate on the plasmonic property of these complex shaped nanostars. The powerful CL-FDTD combination helps us to understand the effect of the substrate on plasmonic response of branched nanoparticles.

View original: http://arxiv.org/abs/1306.5230