Hot carriers generated by plasmons: where are they generated and where do they go from there?

A physically transparent unified theory of optically- and plasmon-induced hot carrier generation in metals is developed with all of the relevant mechanisms included. Analytical expressions that estimate the carrier generation rates and their locations, energies and directions of motion are obtained. Among the four mechanisms considered: interband absorption, phonon and defect assisted absorption, electron-electron scattering assisted absorption and surface-collision assisted absorption (Landau damping), it is the last one that generates hot carriers, which are most useful for practical applications in photodetection and photocatalysis.