We have studied theoretical models for intrachain and interchain interactions. It was found that for sufficiently large fields the yields with interacting electrons are as large as those with non interacting electrons in the field free case and that in the relatively small field region recombination process continuous to be greater than 0.25. In the very high field regime it was found that recombination process can even be smaller than 0.25. While the bare electric fields required to the reversal of the singlet triplet ratio are rather larger. We considered the role of heteroatoms in the context of molecular emitter. We showed that in small systems with heteroatoms recombination process can approach the statistical limit. Using the time exact time-dependent approach to the interchain and inter molecular charge transfer within a long range interaction we found that the relative yield of the singlet exciton in polymers is large, the singlet exciton yield increases with chain length in oligomers and in small molecules containing nitrogen hetero atoms, the relative yield of the singlet exciton smaller.
Interaction, Polymers, heteroatoms, exciton
