Fabrication of Nanoshell Arrays Using Directed Assembly of Nanospheres

Extraordinary transmission of light has been observed when light is incident on periodic nanostructures patterned metal films, which results from the interaction between the incident photons and the excited surface plasmon polaritons with wavenumbers constrained by the geometry and periodicity of the surface structure. Usually, the surface patterns are fabricated by Focused Ion Beam (FIB) milling, which is expensive and has low throughput. We employ the nanosphere lithography method to fabricate periodic nanoshell arrays on a gold film as an alternative to FIB milling. In this process, polystyrene nanospheres are deposited on glass substrates as a template for subsequent gold deposition. This results in the close-packed hexagonal nanoshell arrays patterned gold surface. The transmission spectra of the patterned surfaces show strong enhanced transmission in the red and IR wavelength regions, and the peak enhanced transmission wavelengths vary with the chemical environments above the surface.