ELECTRICAL-CONDUCTION IN POLY(PHENYLENEVINYLENE) THIN-FILMS

The conduction mechanisms of undoped poly(phenylenevinylene) (PPV) thi n films are studied by measuring the current-voltage-temperature chara cteristics and the thermally stimulated currents in metal-PPV-metal sa ndwich devices. In the high-temperature range, Poole-Frenkel emission is observed with a mean energy level of the localized states of 0.36 e V from the conduction band. Hopping conduction occurs at lower tempera tures with probable interactions between the localized states. Thermal ly stimulated currents show a complex interface region at the polymer- metal top electrode, confirming previous XPS analysis performed on the se devices.