Dielectric engineering of hot carrier generation by quantized plasmons in embedded silver nanoparticles.

Understanding and controlling properties of plasmon-induced hot carriers is a key step towards next-generation photovoltaic and photocatalytic devices. Here, we uncover a route to engineering hot-carrier generation rates of silver nanoparticles by designed embedding in dielectric host materials. Extending our recently established quantum-mechanical approach to describe the decay of quantized plasmons into hot carriers we capture both external screening by the nanoparticle environment and internal screening by silver d-electrons through an effective electron-electron interaction. We find that hot-carrier generation can be maximized by dielectric engineering the host material such that the energy of the localized surface plasmon coincides with the highest value of the nanoparticle joint density of states and discover a path to control the energy of the carriers and the amount produced, for example a large number of relatively low-energy carriers are obtained by embedding in strongly screening environments.