Plasmonic hot carriers in transition metal nitrides

Transition metal nitrides (TMNs) are well established as hard protective coatings on account of their excellent mechanical properties and chemical stability. With recent advances in synthesis, they are becoming increasingly competitive for their opto-electronic properties as refractory plasmonic materials. However, their potential for plasmonic hot carrier harvesting remains largely unknown. In this talk, we show that certain TMNs have a unique wide-band plasmonic behavior that extends deep into the ultraviolet regime. From first-principles calculations, we predict plasmonic response, hot carrier generation and subsequent thermalization of all group IV, V and VI transition metal nitrides, fully accounting for direct and phonon-assisted transitions as well as electron-electron and electron-phonon scattering mechanisms. We find hot carrier lifetimes and mean free paths in these TMNs comparable to those of gold and silver. Finally, we explore mechanisms responsible for the negative real permittivity extending to high frequencies in TMNs, an exciting prospect for stable ultraviolet plasmonics.