Supporting Info
Local electron beam excitation and substrate effect on the plasmonic response of single gold nanostars Pabitra Das1, Abhitosh Kedia2, Pandian Senthil Kumar2, Nicolas Large3, and Tapas Kumar Chini1,* 1
Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India
2
Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India 3
Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77251-1892
*E-mail: (T.K.C)
[email protected], (P.D)
[email protected] Fax: +91 33 2337 4637.
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Figure S1. LSPR dependence on the tip number. The electron beam impact is indicated in every schematic by the red spot. The e-beam is incident from a plane perpendicular to the image plane. As we can see there is a slight red shift of 10 nm and a 30% decrease in the CL intensity when increasing the number of tips.
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Figure S2. FDTD calculated CL spectra for the model single tip structure as a function of the tip orientation without substrate.
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Figure S3. FDTD Calculated CL spectra for an isolated Au nanosphere (red line) and a Au nanosphere sitting on a Si substrate (black line). They are taken to be the same size as the nanostar core.
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Figure S4. LSPR dependence on the tip length (L) with fixed aperture angle o (=15 ). As we can see the tip LSPR red-shifts and its intensity increases with increasing tip length.
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Figure S5. LSPR dependence on the tip aspect ratio. The length of the tip is kept at L=50 nm and the value of D varies. The aspect ratio L/D then varies from 1 to 2.5. We observe a large red-shift of the LSPR with increasing aspect ratios.
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