Channels, OLEDs

An often harmful effect in conjugated polymers is aggregation via locally enhanced interchain interaction. It depresses the excited-state energy in the dimer/aggregate. If the oscillator strength of the lowest transition is lower than average this causes a prolongation of the fluorescence lifetime and, since nonra-diative channels are not affected, a decrease of the fluorescence efficiency that is detrimental for OLEDs. 

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