Exciton-plasmon interaction and photo-injection of plasmonic hot carriers in hybrid nanostructures

We investigate theoretically the effects of exciton-plasmon interaction and plasmon-assisted carrier injection in a hybrid semiconductor-metal nanostructure under resonant optical excitation. We treat the coupling between the metal and semiconductor nanocrystals using a many-body Fano model and a quantum density-matrix formalism. Hot carriers have a characteristic energy distribution in the plasmon wave function in a metal nanocrystal and participate in tunnel and ballistic injection currents to the neighboring semiconductor nanostructure. The photo-current induced by hot plasmonic electrons in the nanostructure depends on the barrier height, excitation frequency, plasmon energy, relaxation rates, and geometry of a device. The Coulomb exciton-plasmon interaction may also play an essential role in the optical absorption and electron injection. The results obtained in this study can be used to design and describe a variety of plasmonic nanodevices with hot electron injection for photo-catalysis, light-harvesting, and solar cells.