Non-volatile and volatile bipolar resistive electrical switching in Ag and Cu chalcogenide memories with a dedicated switching layer

We report on the realisation of bipolar resistive electrical switching in memories based on inorganic solid ionic conductors, where the switching is localized in a dedicated switching layer. The switching mechanism is the electrochemical formation of a conductive metallic filament that bridges an insulating switching layer (ON state) and its reversible dissolution (OFF state). These memories have moderate write voltages of ~3V, excellent ON/OFF current ratios of ~10³ and write/erase cyclic endurances of ~10⁴ cycles. For the first time, volatile switching behaviour has been reported for cation-conduction based nanoionic memories. This phenomenon has been explained based on electromigration-induced filament rupture.