Forming free bipolar resistive switching in SiO_x-based flexible MIM devices

SiO_x-based resistive switching (RS) cells composed of Cu as the active electrode were fabricated on flexible muscovite mica flakes using DC and radio frequency magnetron sputtering techniques. In one set of the metal–insulator–metal (MIM) devices, Cu-nanoparticles (Cu-NPs) have been embedded into the SiO_x layer and their RS properties have been compared with the devices without the Cu-NPs. All the devices exhibited forming free bipolar RS characteristics. Room temperature DC current–voltage (I–V) measurements suggest improved resistance windows for the Cu-NP-embedded MIM devices. Analysis of the DC I–V characteristics suggests electrochemical metallization-driven RS, where current conduction follows Ohmic and space-charge-limited conductions mechanism for low and high resistance states, respectively. The resistance windows of the Cu-NPs-embedded MIM structures tested for multiple cycles do not degrade under different bending conditions, indicating their mechanical robustness for potential flexible device applications.