  Hybrid inorganic-organic semiconductor interfaces are of interest for new
photovoltaic devices operating above the Shockley-Queisser limit. Predicting
energy band alignment at the interfaces is crucial for their design, but
represents a challenging problem due to the large scales of the system, the
energy precision required and a wide range of physical phenomena that occur at
the interface. To tackle this problem, we use many-body perturbation theory in
the non-self-consistent GW approximation, orbital relaxation corrections for
organic semiconductors, and line-up potential method for inorganic
semiconductors which allows for tractable and accurate computing of energy band
alignment in crystalline van-der-Waals hybrid inorganic-organic semiconductor
interfaces. In this work, we study crystalline tetracene physisorbed on the
clean hydrogen-passivated 1x2 reconstructed (100) silicon surface. Using this
computational approach, we find that the energy band alignment is determined by
an interplay of the mutual dynamic dielectric screening of two materials and
the formation of a dipole layer due to a weak hybridization of atomic/molecular
orbitals at the interface. We also emphasize the significant role of the
exchange-correlation effects in predicting band offsets for the hybrid
inorganic-organic semiconductor interfaces.
