Abstract
The quantum-dynamical mechanism of photoinduced subpicosecond exciton dissociation and the concomitant formation of a charge-separated state at a semiconducting polymer heterojunction is elucidated. The analysis is based upon a two-state vibronic coupling Hamiltonian including an explicit 24-mode representation of a phonon bath comprising high-frequency (CC stretch) and low-frequency (torsional) modes. The initial relaxation behavior is characterized by coherent oscillations, along with the decay through an extended nonadiabatic coupling region. This region is located in the vicinity of a conical intersection hypersurface. A central ingredient of the analysis is a novel effective mode representation, which highlights the role of the low-frequency modes in the nonadiabatic dynamics. Quantum dynamical simulations were carried out using the multiconfiguration time-dependent Hartree method.
Original language | English |
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Article number | 021103 |
Journal | Journal of Chemical Physics |
Volume | 126 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2007 |
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry