  Charge excitations in Mott insulators (MIs) are distinct from their
band-insulator counterparts and they can provide a mechanism for energy
harvesting in solar cells based on strongly correlated electronic materials. In
this paper, we study the real-time dynamics of holon-doublon pairs in a MI
connected to metallic leads using the time-dependent density matrix
renormalization group method. The transfer of charge across the MI-metal
interface is controlled by both the electron-electron interaction strength
within the MI and the voltage difference between the leads. We find an overall
enhancement of the charge transfer as compared to the case of a
(noninteracting) band insulator-metal interface with a similar band gap.
Moreover, the propagation of holon-doublon excitations within the MI
dynamically changes the spin-spin correlations, introducing time-dependent
phase shifts in the spin structure factor.
