Switching effect in poly(p-phenylenevinylene)

A switching effect was investigated in poly( p-phenylenevinylene) (PPV). N- shaped current-voltage (I-V) characteristics of thick ITO-PPV-Al structures were observed, which correspond to switching at a threshold voltage typica lly in the range 2-5 V from a conducting to a resistive state. The behaviou r was independent of the polarity of the applied voltage and the sweep dire ction. At the threshold voltage, the current changes by approximately one a nd a half orders of magnitude of its previous value. Pulsed measurements sh ow that the transition time from one to the other conductive state is less than 1 mu s. The switching effect can be associated with strongly localized current pathways. (C) 2000 Elsevier Science S.A. All rights reserved.