A many-body perturbation theory approach to energy band alignment at the crystalline tetracene-silicon interface

Abstract: 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.