  We investigate the photocurrent and spectral features in a simplified model
of a Mott photovoltaic system consisting of a multilayered insulating
heterostructure. The central correlated region is coupled to two metallic leads
kept at different chemical potentials. A periodic drive applied to the
correlated region produces excited doublons and holons across the Mott gap
which are then separated by a potential gradient, which mimics the
polarization-induced electric field present in oxyde heterostructures. The
nonequilibrium Floquet steady-state is addressed by means of dynamical
mean-field theory and its Floquet extension, while the so-called auxiliary
master equation approach is employed as impurity solver. We find that impact
ionization, identified by a kink in the photocurrent as function of the driving
frequency, becomes significant and is generally favoured by weak, narrow-band
hybridizations to the leads beyond a certain strength of the driving field. On
the other hand, in the case of a direct coupling to metallic leads with a flat
band, we observe a drastic reduction of impact ionization and of the
photocurrent itself.
