Evaluation of the External Reorganization Energy of Polyacenes

Abstract

The external reorganization energy for hole transport in naphthalene, anthracene, tetracene, pentacene, and rubrene is computed using a polarizable force field. The importance of this very small contribution to the Hamiltonian of the molecular crystal in the context of charge-transport modeling is discussed. The effect of the force field parameters and the size of the model system on the computed reorganization energy is analyzed. The results are rationalized with a simple model which clarifies the fundamental differences between the external reorganization energy in the solid and liquid phases.