CC Liang, WH Chang, CH Lin – Journal of Materials Chemistry C, 2016
This study presents a novel process based on nanotransfer printing (NTP) for fabricating gold nano-pleat arrays. Gold film deposited over nano-ridge arrays on a perfluoropolyether (PFPE) mold was transferred directly to an NOA63 film on a glass substrate. Width of the nanocavities on the nano-pleat array can be dramatically reduced compared with the width of the nanoridges on the mold, thus avoiding the difficulty of replicating nano-features from a master mold to a soft mold. The mechanisms of remarkable reduction in the nanocavity width during the gold sputtering process were investigated. A nano-pleat array with a nanocavity width of 20 nm transferred from a PFPE mold with 80 nm features was successfully achieved. Plasmonic properties of nano-pleat arrays were investigated numerically and experimentally. A sharp dip was found between two coupling modes in the measured spectrum, and its bandwidth reached as small as 13.1 nm. Phase dip was used for refractive index sensing, demonstrating a good sensitivity of 525.5 nm/RIU with a figure of merit of 40.1. The proposed fabrication process only involved ion sputter coating of gold film and one-step NTP. Thus, nano-pleat arrays are promising candidates as surface plasmon sensors.
… Transmission spectra were measured on a miniature UV-VIS- NIR spectrometer (BLACK-Comet-CSR-SR model, StellarNet Inc., USA) with a polarizer placed between the sample and
the light source (tungsten halogen lamp, SL1-FILTER, StellarNet Inc., USA). …
