External electric field effects on the fluorescence of methylene-linked pyrene and N,N-dimethylaniline doped in a PMMA polymer film

Fluorescence emitted from the pyrene chromophore is quenched by an electric field and both intra- and intermolecular electron transfer processes from N,N-dimethylaniline (DMA) to the excited state of pyrene are suggested as being enhanced by an electric field in a methylene-linked compound of pyrene and DMA doped in a PMMA polymer film. Exciplex fluorescence, which appears as a result of photoinduced electron transfer, shows field-induced enhancement and quenching, depending on the concentration. Quenching of the exciplex fluorescence observed at high concentrations is attributed to a photocarrier generation.