title: Exciton dissociation at donor-acceptor heterojunctions: dynamics using the collective effective mode representation of the spin-boson model.
abstract: Following the recent quantum dynamics investigation of the charge transfer at an oligothiophene-fullerene heterojunction by the multi-configuration time dependent Hartree method [H. Tamura, R. Martinazzo, M. Ruckenbauer and I. Burghardt, J. Chem. Phys. 137, 22A540 (2012)], we revisit the transfer process by a perturbative non-Markovian master equation treated by the time local auxiliary density matrix approach. We compare the efficiency of the spin-boson model calibrated by quantum chemistry with the effective mode representation. A collective mode is extracted from the spin-boson spectral density. It is weakly coupled to a residual bath of vibrational modes, allowing second-order dynamics. The electron transfer is analyzed for a sampling of inter-fragment distances showing the fine interplay of the electronic coupling and energy gap on the relaxation. The electronic coherence, expected to play a role in the process, is preserved during about 200 fs.
authors: Laboratoire de Chimie Physique, Bât 349, Université Paris-Sud, UMR 8000, F-91405 Orsay, France.
authors: Aurélie
authors: A
authors: Chenel
authors: Laboratoire de Chimie Physique, Bât 349, Université Paris-Sud, UMR 8000, F-91405 Orsay, France.
authors: Etienne
authors: E
authors: Mangaud
authors: Institut für Physikalische und Theoretische Chemie, Goethe Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany.
authors: Irene
authors: I
authors: Burghardt
authors: Laboratoire Collisions, Agrégats, Réactivité, UMR 5589, IRSAMC, Université Paul Sabatier, F-31062 Toulouse, France.
authors: Christoph
authors: C
authors: Meier
authors: Laboratoire de Chimie Physique, Bât 349, Université Paris-Sud, UMR 8000, F-91405 Orsay, France.
authors: Michèle
authors: M
authors: Desouter-Lecomte