ORIGIN AND STABILIZATION OF PHOTOEXCITATIONS IN CONJUGATED POLYMERS

We report studies on the nature of photoexcitations in onedimensional organic semiconductors using photoluminescence, absorption and photoin duced absorption techniques. The polymers of interest-ladder-type poly (para-phenylenes) (LPPPs)-show high intrachain order and a small distr ibution of effective conjugation lengths, which makes them a perfect m odel system for conjugated polymers. The influence of the effective co njugation length on the energetic position and the stabilization of ph otoexcited charged and neutral states is investigated. Interchain inte ractions are discussed on the base of optical spectroscopy under hydro static pressure.