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Title: Exciton dissociation at donor-acceptor heterojunctions: Dynamics using the collective effective mode representation of the spin-boson model

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:
;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [5]
  1. Laboratoire de Chimie Physique, Bât 349, Université Paris-Sud, UMR 8000, F-91405 Orsay (France)
  2. (France)
  3. Institut für Physikalische und Theoretische Chemie, Goethe Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main (Germany)
  4. Laboratoire Collisions, Agrégats, Réactivité, UMR 5589, IRSAMC, Université Paul Sabatier, F-31062 Toulouse (France)
  5. (Belgium)
Publication Date:
OSTI Identifier:
22255231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; BOSONS; DENSITY MATRIX; DISSOCIATION; EFFICIENCY; ELECTRON TRANSFER; ENERGY GAP; FULLERENES; HETEROJUNCTIONS; SPECTRAL DENSITY; SPIN; TIME DEPENDENCE