Exciton trapping in one-dimensional systems with correlated disorder

Abstract

Numerical investigations of the trapping of Frenkel excitons in one-dimensional lattices with interstitial traps randomly placed in pairs are presented. The probabilities of finding the exciton both in the q = 0 mode P(t) and in any mode Q(t) have been obtained following the numerical approach recently developed by Huber and Ching [Phys. Rev. B 42, 7718 (1990)] for unpaired traps. We have found that the pairing of traps enhances both probabilities at all times, in comparison with lattices containing the same fraction of unpaired traps. We suggest that this behavior is related to the occurrence of larger segments of the lattice that are free of traps, where there exists a major contribution of the slowly decaying modes.