SPECTROSCOPY OF CONJUGATED POLYMERS

The dynamics of optical excitations in conjugated polymers is often tr eated in terms of the one-electron semiconductor band picture applied to an infinitely extended polymer chain with strong electron-phonon co upling but ignoring coulomb and electron correlation effects. The alte rnative view is that the polymer be considered as composed of conjugat ed segments separated by topological faults and establishing a manifol d of localized chromophores that control absorption, fluorescence, as well as energy and charge transport. The latter concept is supported b y (i) energy selective and time resolved fluorescence spectroscopy, (i i) electroabsorption work, (iii) absorption spectroscopy of chemically produced ionic states and (iv) photoconductivity.