Effect of Tamm Surface States on Landau Damping in Metal–Semiconductor Nanostructures

The hot electron generation in plasmonic nanoparticles is the key to efficient plasmonic photocatalysis. Here, the effect of Tamm states (TSs) at the metal–semiconductor interface on hot electron generation and Landau damping (LD) in metal nanoparticles is studied theoretically for the first time. TSs can lead to resonant hot electron generation and to the LD rate enhanced by several times. The resonant hot electron generation is reinforced by the transition absorption due to the jump of the permittivity at the metal–semiconductor interface. Since electron states in the metal and the quasi‐discrete TS are coupled coherently (“bound state in continuum”), the absorption spectrum of light by electrons has a Fano‐type shape. The results demonstrate clearly the importance of taking into account details of the semiconductor band structure and surface states at the metal–semiconductor interface, including Tamm surface states, for a proper description of the hot carrier generation and LD. The results are in correspondence with earlier experimental works on coherent electron transport and chemical‐induced damping in plasmonic nanostructures. Thus, by judicious selection of semiconductor materials with Tamm surface states one can engineer decay rates and hot carrier production for important applications, such as photodetection and photochemistry.