| Abstract
| - The effect of electric fields on the fluorescence decayof block-copolymers containing poly(p-phenylenevinylene) (PPV) and polynorbornene (polyNBE) was measured.Electric fields of up to 200 V/μm do notperturb the fluorescence decay profiles when the average size of thePPV block is small (i.e.,PPV3-block-polyNBE200or PPV3-block-polyNBE25). Itappears that for short isolated PPV segments the electric fieldaccessible for thesestudies does not allow dissociation of photogenerated excitons intoelectron-hole pairs. For larger PPV segments,as in PPV20-block-polyNBE200, theelectric field reduces considerably the fluorescence lifetime andquantum yield.In addition, irradiating the sample under an electric fieldchanges permanently its fluorescence characteristics.Controlexperiments show that neither irradiation nor the field alone candegrade the polymer.
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