TIME-RESOLVED LUMINESCENCE STUDY OF RECOMBINATION PROCESSES IN ELECTROLUMINESCENT POLYMERS

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