Delocalization effects in singlet fission: Comparing models with two and three interacting molecules
Open Access
- 28 June 2020
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 152 (24), 244125
- https://doi.org/10.1063/5.0009914
Abstract
We present surface hopping simulations of singlet fission in 2,5-bis(fluorene-9-ylidene)-2,5-dihydrothiophene (ThBF). In particular, we performed simulations based on quantum mechanics/molecular mechanics (QM/MM) schemes in which either two or three ThBF molecules are inserted in the QM region and embedded in their MM crystal environment. Our aim was to investigate the changes in the photodynamics that are brought about by extending the delocalization of the excited states beyond the minimal model of a dimer. In the simulations based on the trimer model, compared to the dimer-based ones, we observed a faster time evolution of the state populations, with the largest differences associated with both the rise and decay times for the intermediate charge transfer states. Moreover, for the trimer, we predicted a singlet fission quantum yield of similar to 204%, which is larger than both the one extracted for the dimer (similar to 179%) and the theoretical upper limit of 200% for the dimer-based model of singlet fission. Although our study cannot account for the effects of extending the delocalization beyond three molecules, our findings clearly indicate how and why the singlet fission dynamics can be affected.Funding Information
- European Commission (ITN-EJD- 642294-TCCM)
- Università di Pisa (PRA 2018 36)
This publication has 43 references indexed in Scilit:
- Theoretical Modeling of Singlet FissionChemical Reviews, 2018
- Theoretical Studies of Singlet Fission: Searching for Materials and Exploring MechanismsChempluschem, 2018
- Singlet Exciton Fission PhotovoltaicsAccounts of Chemical Research, 2013
- Recent Advances in Singlet FissionAnnual Review of Physical Chemistry, 2013
- Ultrafast Dynamics of Exciton Fission in Polycrystalline PentaceneJournal of the American Chemical Society, 2011
- Singlet FissionChemical Reviews, 2010
- Excited state dynamics in solid and monomeric tetracene: The roles of superradiance and exciton fissionThe Journal of Chemical Physics, 2010
- Morphology Effectively Controls Singlet-Triplet Exciton Relaxation and Charge Transport in Organic SemiconductorsPhysical Review Letters, 2009
- Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbersJournal of Applied Physics, 2006
- Detailed Balance Limit of Efficiency of p-n Junction Solar CellsJournal of Applied Physics, 1961