Hot carrier generation in plasmonic nanostructures: Physics and device applications

Excitation of localized surface plasmon resonances (LSPR) in metallic nanostructures enables efficient absorption and spatial confinement of light energy. The plasmon excitations, however, decay rapidly into heat; this is a major problem in the effective utilization of plasmonic nanostructures for nanoscale energy conversion and optoelectronic device applications. The decay of plasmon excitations involves the generation of energetic hot carriers before the eventual thermalization. These energetic carriers, if suitably extracted before thermalization, can drive chemical reactions and, in conjunction with semiconductors, enable nanoscale photochemical or photovoltaic energy conversion. This chapter discusses the theory of hot carrier generation and the applications of this phenomenon to drive chemical reactions and for nanoscale photodetectors.