Plasmon coupling in self-assembled gold nanoparticle-based honeycomb islands

Metallic nanostructures that sustain plasmonic resonances are indispensable ingredients for many functional devices. Whereas structures fabricated with top-down methods entail the advantage of a nearly unlimited control over all plasmonic properties, they are in most cases unsuitable for a low cost fabrication on large surfaces; and eventually a truly nanometric size domain is difficult to reach due to limitations in the fabrication resolution. Although ordinary bottom-up techniques based on colloidal nanolithography promise to lift these limitations, they often suffer from their incapability to self-assemble nanoparticles at large surfaces and at a density necessary to observe effects that strongly deviate from those of isolated nanoparticles. Here, we rely on the application of sequential bottom-up fabrication steps to realize honeycomb structures from gold nanoparticles that show strong extinction bands in the near-infrared. The extraordinary properties are only facilitated by densely packing the nanop...