Variation of switching mechanism in TiO2 thin film resistive random access memory with Ag and graphene electrodes

We report the fabrication of resistive random access memory (ReRAM) on both Si and PET flexible substrates using TiO2 as the dielectric spacer between Ag electrodes. Ag/TiO2/Ag ReRAM shows unipolar switching behavior with a ramping rate of 50 mV. We further examined the switching mechanism for Ag based ReRAM in the low resistive state (LRS) and high resistive states (HRS). To elucidate the impact of electrode material on the switching mechanism, we fabricated a graphene/TiO2/graphene ReRAM device and observed that the switching behavior changed from unipolar to bipolar due to the unique physical properties of graphene. This study demonstrates ReRAM based on Ag and graphene electrodes on both Si and PET substrates, and directly demonstrates the strong dependence of electrode materials on the switching mechanism.