EXCITONS AND INTERBAND EXCITATIONS IN CONDUCTING POLYMERS BASED ON PHENYLENE

A microscopic model for the photoexcitations of polyphenylenes is introduced. It allows for the effects of the ''correlation-energy gap'' U between charged and charge-neutral excitations and the dipole-dipole interaction V between neighboring monomers. It leads to the generic appearance of three dispersing absorption bands whose relative spacings in energy rue largely set by Lr and the electronic bandwidth W, thereby establishing direct experimental access to these microscopic parameters.