Molecular polaron states in polyacene crystals. Formation and transfer processes Original Research Article

A combined application of the methods of quantum chemical calculations, extended Marcus electron transfer theory and generalized polaron theory approaches have been used for the description of molecular polaron formation and transfer processes in polyacene crystals. Energies of internal reorganization of molecular ion and formation of molecular polaron (MP) have been calculated and refined calculations of the transfer (hopping) integral Jmn values performed for anthracene crystal. All possible types of charge carrier interaction with the crystalline environment, causing polaron formation, have been analyzed in terms of a Hamiltonian model description. The conditions of molecular polaron formation and activationless transfer, dominant in polyacene crystals, are formulated. Comparative analyses of charge carrier (polaron) transfer theories are carried out and the validity limits and relevance of the Marcus transfer theory in comparison with more rigorous polaron theories are discussed. The results of theoretical approaches are compared with earlier phenomenological description of MP formation and transport in OMC based on computer simulation and reported experimental data.