Bottom-up and top-down strategies for molecular plasmonics
Abstract
The wealth of properties presented by noble metal nanostructures, ranging from catalysis to nanomedicine, has given birth to the field of plasmonics. More specifically, molecular plasmonics deals with surface plasmon interacting with real or artificial molecules. For instance, plasmonic nanostructures can increase the brightness of a nearby quantum emitter, a phenomenon known as metal-enhanced fluorescence. The underlying physical processes are now well known, namely alterations of the emitter’s internal quantum yield and radiation pattern, and of the local pump power. All these effects strongly depend on the emitter-metal nanoparticle distance, and the transition between the enhancement and quenching regimes occurs within a few nanometers. Precise control of this distance is thus required, and it remains a quite tricky task. In this talk, I will present results on plasmonic fluorescence enhancement obtained using bottom-up and top-down strategies: • A system fabricated using a bottom-up approach, consisting of a metallic core surrounded by multilayers of polyelectrolytes; • An integrated system, where a single layer of silicon nanocrystals is placed at a controllable distance from gold nanoparticles by combining e-beam lithography and reactive ion etching. I will also present new techniques we have developed to fabricate aluminum nanoparticles. These particles present surface plasmon resonances in the ultraviolet range, allowing to shift molecular plasmonics towards higher energies.