Enhancing Reproducibility and Nonlocal Effects in Film-Coupled Nanoantennas

Nanopatch antennas based on the assembly of nanocubes are an appealing way to easily produce structures that feature very thin gaps between metals at a very low cost compared with other surface modification techniques. If these coatings are very good absorbers in the visible and near-infrared range, they can also be of interest for reaching light confinement regimes where nonlocality arises strongly, or for designing molecular electronics junctions embedded in resonating cavities. Here both modeling and experimental realization of a nanocube assembly approach based on alkyldithiols molecules is proposed that enables a high reproducibility on the resonance position of the cavities, as well as gaps that are thinner than the usual 3 nm limit often reported in the literature, thus opening the way to experimental confirmation of nonlocal effects as well as new perspectives for molecular electronics.