1. Switching between Coherent and Incoherent Singlet Fission via Solvent-Induced Symmetry Breaking
- Author
-
Andrew J. Musser, Antonios M. Alvertis, Eric G. Fuemmeler, Jiaqi Feng, Timothy J. H. Hele, Steven Lukman, Alex W. Chin, Jishan Wu, Neil C. Greenham, University of Cambridge [UK] (CAM), Agency for science, technology and research [Singapore] (A*STAR), Cornell University [New York], National University of Singapore (NUS), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Sheffield], and University of Sheffield [Sheffield]
- Subjects
Physical and chemical processes ,Exciton ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,[CHIM]Chemical Sciences ,Symmetry breaking ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,Mixing (physics) ,Energy ,Nuclear fission ,Charge (physics) ,General Chemistry ,0104 chemical sciences ,Organic semiconductor ,Tetracene ,chemistry ,Chemical physics ,Intramolecular force ,Oligomers ,Singlet fission ,Solvents - Abstract
International audience; Singlet fission in organic semiconductors causes a singlet exciton to decay into a pair of triplet excitons and holds potential for increasing the efficiency of photovoltaic devices. In this combined experimental and theoretical study, we reveal that a covalent dimer of the organic semiconductor tetracene undergoes activated singlet fission by qualitatively different mechanisms depending on the solvent environment. We show that intramolecular vibrations are an integral part of this mechanism, giving rise to mixing between charge transfer and triplet pair excitations. Either coherent or incoherent singlet fission can occur, depending on the transient solvent-induced energetic proximity between the states, giving rise to complex variation of the singlet fission mechanism and time scale in the different environments. Our results suggest a more general principle for controlling the efficiency of photochemical reactions by utilizing transient interactions to tune the energetics of reactant and product states and switch between incoherent and coherent dynamic
- Published
- 2019
- Full Text
- View/download PDF