Mechanism for bistability in organic memory elements

We demonstrate that the resistive switching phenomenon observed in organic semiconductor layers containing granular metal particles conforms to a charge storage mechanism described by Simmons and Verderber [Proc. R. Soc. A 391, 77 (1967)]. The space-charge field due to the stored charge inhibits further charge injection from the electrodes. The equilibrium current-voltage curve is N shaped and the low and high resistance states are obtained by applying voltage close to the local maximum and minimum, respectively. (C) 2004 American Institute of Physics.