Electronic International Standard Serial Number (EISSN)
Polymer-based guest-host systems represent a promising class of materials for efficient light-emitting diodes. The energy transfer from the polymer host to the guest is the key process in light generation. Therefore, microscopic descriptions of the different mechanisms involved in the energy transfer can contribute to enlighten the basis of the highly efficient light harvesting observed in this kind of materials.Herein, the nature of intramolecular energy transfer in a dye-end-capped conjugated polymeris explored by using atomistic non adiabatic excited-state molecular dynamics. Linear peryleneend-capped (PEC) polyindenofluorenes (PIF), consisting of n(n = 2, 4, and 6) repeat units, i.e., PEC-PIF no ligomers, are considered as model systems. After photoexcitation at the oligomerabsorption maximum, an initial excit on becomes self-trapped on one of the monomer units (donors). Thereafter, an efficient ultrafast through-space energy transfer from this unit to the peryleneacceptor takes place. We observe that this energy transfer occur sequally well for many monomer unit on the chain. Effective specific vibronic couplings between each monomer and the accept or are identified. The seoligomer → end-cap energy transfer steps do not match with the rates predicted by Forster - type energy transfer. The through-space and through- bond mechanisms are two distinct channels of energy transfer. The former dominates the over all process, where as the through- bond energy transfer between in denofluorene monomer units along the oligomer back bone only makes a minor contribution.