Dynamic Processes of Resistive Switching in Metallic Filament-Based Organic Memory Devices

Abstract

Dynamic formation/rupture processes of metallic filament have been clarified in solid electrolyte- and oxide-based resistive memory devices, whereas they remain exclusive in organic ones. Here we report these dynamic processes in Cu/poly (3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester/indium–tin oxide (ITO) structure, which exhibits a typical bipolar resistive switching effect. Under illumination, an open circuit voltage of −0.15 V exists in high-resistance state, yet it vanishes in low-resistance state owing to the emergence of Cu filament. By combining the symmetry of current–voltage curves with corresponding energy band diagrams in different resistance states, it is demonstrated that the Cu filament grows from Cu/organics interface, ends at organics/ITO interface, and ruptures near organics/ITO interface. This work might advance the insight into resistive switching mechanisms in organic-based resistive memories.