Electronic Polarization Effects upon Charge Injection in Oligoacene Molecular Crystals: Description via a Polarizable Force Field

Understanding the nature and magnitude of the electronic polarization due to the presence of a charge carrier in organic molecular solids is of fundamental importance in the description of charge-carrier transport. We present an approach to study these effects based on a polarizable force field that accounts for charge, dipole, quadrupole, and induced-dipole interactions. To demonstrate its general applicability, the method is applied to the oligoacene crystal series (naphthalene through pentacene) and perfluorinated derivatives of naphthalene and pentacene. Very good qualitative agreement with experimental results is achieved in terms of both the magnitude and asymmetry of the polarization as a function of the sign of the injected charge, with improved quantitative agreement versus previous theoretical assessments.