Intermolecular Vibrational Modes Speed Up Singlet Fission in Perylenediimide Crystals.
We report numerical simulations based on a non-Markovian density matrix propagation scheme of singlet fission (SF) in molecular crystals. Ab initio electronic structure calculations were used to parametrize the exciton and phonon Hamiltonian as well as the interactions between the exciton and the intramolecular and intermolecular vibrational modes. We demonstrate that the interactions of the exciton with intermolecular vibrational modes are highly sensitive to the stacking geometry of the crystal and can, in certain cases, significantly accelerate SF. This result may help in understanding the fast SF experimentally observed in a broad range of molecular crystals and offers a new direction for the engineering of efficient SF sensitizers.
Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2629BL Delft, The Netherlands.
Nicolas
N
Renaud
Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2629BL Delft, The Netherlands.
Ferdinand C
FC
Grozema
exciton−phonon interactions; non-Markovian dynamics; organic photovoltaics; solar energy