TIME-RESOLVED LUMINESCENCE STUDY OF RECOMBINATION PROCESSES IN ELECTROLUMINESCENT POLYMERS

Picosecond luminescence studies on poly(p-phenylene vinylene) (PPV) an d related compounds in the temperature range of 10-300 K are reported. We identify a fast nonradiative and considerably slower radiative rec ombination channel. The fastest decay is observed in PPV. In the pheny l substituted derivative poly(phenyl-p-phenylenevinylene) a significan t contribution from a slow component (approximately 1.3 ns) is found. Dilution of the polymer in a blend leads to an increase of the contrib ution of the slow component. We attribute the fast decay to luminescen ce quenching due to energy dependent trapping of mobile excitations wh ereas the slow component reflects the radiative recombination.