Nanoplasmonic hot carriers: from excitation to catalysis

Localized surface plasmons in metallic nanoparticles give rise to very strong light absorption. The decay of these excitations results in the generation of energetic or “hot” electrons and holes which can be harvested and harnessed for applications in photovoltaics, photocatalysis and light sensing. To optimize hot carrier production in devices, a detailed theoretical understanding of the relevant microscopic processes, including light-matter interactions, plasmon decay and hot electron thermalization, is needed. In my talk, I will describe a material-specific theory of hot-carrier generation and relaxation in metallic nanoparticles which combines a classical description of the electromagnetic radiation with large-scale atomistic quantum-mechanical simulations. I will present results for hot carrier distributions in spherical nanoparticles of gold, silver and copper and discuss the relative importance of interband and intraband transitions as function of nanoparticle size. Next, I will describe how CO2 reduction performance of gold nanoparticles can be enhanced by changing the nanoparticle shape. Finally, I will present results for bimetallic Au-Pd photocatalysts and demonstrate a large enhancement in hydrogen production can be achieved in antenna-reactor architectures.