Plasmon induced light harvesting

Plasmon energies can be tuned across the spectrum by simply changing the geometrical shape of a nanostructure. Plasmons can efficiently capture incident light and focus it to nanometer sized hotspots which can enhance electronic and vibrational excitations in nearby structures [1]. Another important but still relatively unexplored property of plasmons, is that they can be efficient sources of hot energetic electrons which can transfer into nearby structures and induce a variety of processes. This process is a quantum mechanical effect: the decay of plasmon quanta into electron-hole pairs. I will discuss how plasmon induced hot electrons can be used in various applications: such as to induce chemical reactions in molecules physisorbed on a nanoparticle surface [2-3]; to inject electrons directly into the conduction band of a nearby substrate [4,5]; and to induce local doping of a nearby graphene sheet [6]. Finally I will discuss a recent discovery that conducting nanoparticle dispersed in a liquid are able to convert sunlight directly into steam without significant heating of the liquid [7].