Impact of bridging units on the dynamics of photoinduced charge generation and charge recombination in donor-acceptor dyads.
We estimate, at a full quantum-chemical level, the various molecular parameters governing the rate of photoinduced charge generation and charge recombination in model organic structures containing a donor and an acceptor unit in view of the possible use of such systems in organic solar cells. The rate of through-space excitation dissociation, as predicted in the framework of the Marcus-Levich-Jortner theory, is found to be low in comparison to intramolecular decay processes when the donor and acceptor molecules are lying in a head-to-tail arrangement and high when the donor and acceptor molecules are superimposed in a cofacial arrangement. The charge separation rates for side-by-side donor-acceptor dyads are significantly increased by promoting through-bond interactions in covalently linked donor and acceptor units. This has motivated a detailed quantitative analysis of the influence of the nature, size, and conformation of the bridging moiety on the calculated transfer rates.
Van Vooren
Antoine
A
Laboratory for Chemistry of Novel Materials, University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium.
Lemaur
Vincent
V
Ye
Aijun
A
Beljonne
David
D
Cornil
Jérôme
J