Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers

The interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices were studied. The significance of quenching of excited states in polymeric devices was demonstrated by interlayer quenching constants between fluorescent molecules and doped polymer in a layered sample. The polymer was a chiral 3-substituted polythiophene (POWT) and the fluorescent molecule was fluorescein bound to dextran (D-FITC). When the POWT was electrochemically dedoped, the photoluminescence in the polymer layer was enhanced by excitation transfer from fluorescein layer. Thus the photoluminescence from the polythiophene disappeared rapidly as soon as the layer was doped.