The interchain coupling and exciton in conjugated polymers

The exciton states in two coupled conjugated polymer chains are studied. These two chains are modeled individually by the Su-Schrieffer-Heeger Hamiltonian and coupled by an interchain electron-transfer term. Both the intra- and inter-chain long range Coulomb interactions are taken into account. It is found that, for parallel and anti-parallel orderings, the features of excitons are quite different. Possible implications for the experiment of luminescent polymers are also addressed.