DYNAMICS OF PHOTOEXCITATIONS IN ELECTRIC-FIELDS IN POLY(P-PHENYLENEVINYLENE) DIODES

We report on a study of the dissociation of neutral photo excitations in electric fields in ITO/poly(p-phenylenevinylene) (PPV)/Al diodes. T his process leads simultaneously to photoconductivity and field-induce d quenching of the photoluminescence. By illuminating the samples thro ugh the different contacts we show that the high electric fields are r estricted to a region close to the Al layer as characteristic for a Sc hottky diode. Time-resolved luminescence measurements show that the di ssociation takes place on a picosecond time scale. The experimental da ta are compared with a Monte-Carlo simulation of the dynamics of photo excitations created in a disorder-broadened density of states.