Impact of the Counter-Electrode Material on Redox Processes in Resistive Switching Memories

Cation-based resistive-switching memories rely on the injection and drift of metal ions in nanoscale thin films. In insulators that do not initially contain mobile cations, such as SiO2, Ta2O5, and so forth, water redox reactions occurring at the counter electrode (CE) were found to be essential in enabling the dissolution of the active electrode and to keep electroneutrality. In this study, we report on the impact of the CE on redox processes prior to resistive switching. Potentiodynamic measurements for various electrode materials revealed that the catalytic activity of the CE towards the water redox process determines the concentration of dissolved ions within the oxide and influences the rate of the total cell reaction. This trend can be used as an indicator for the design of both cation- and anion-conducting oxide-based resistive-switching random-access memories.