Dresden 2011 – wissenschaftliches Programm
O 18.2: Vortrag
Montag, 14. März 2011, 17:30–17:45, PHY C213
Fabrication of high-quality large-area plasmonic oligomers — •Jun Zhao, Bettina Frank, and Harald Giessen — Universität Stuttgart
Plasmonic structures with a structure size of around 100nm are tremendously important for applications in the visible and near-IR range. Surface-enhanced Raman scattering substrates, localized surface plasmon resonance sensors, narrow resonances using plasmonic induced transparency, and local field concentration in oligomers to create hot spots are among those applications. Key issues in the design and manufacturing of such structures are small gaps in the range of sub-20nm, sharp edges, and narrow resonances. For applications, large fabrication areas in the range of cm2 and low manufacturing costs are crucial. Here, we present a method that fulfils these requirements. Utilizing tilted-angle-rotation lithography with a polar and azimuthal rotation axis and shutter control together with monolayers of polystyrene spheres we create reproducibly homogeneous structures in 50nm to 200nm range with 10nm gaps over areas of cm2. We fabricated triangular monomers, dimers, trimers, quadrumers, and pentamers, with open and closed gaps and with different size of nanospheres, and measured their transmittance spectra by FTIR microscopy. The spectra show well modulated resonances which depend sensitively on the incident polarization. We can attribute the various collective modes to the different features of the spectra and observe hybridization effects. This confirms the high quality of our fabrication method.