Dual Buffer Layers for Developing Electrochemical Metallization Memory With Low Current and High Endurance

In this letter, the dual buffer layers of AgInSbTe (AIST) and monolayer defective graphene (DG) are introduced into amorphous carbon (a-C)-based electrochemical metallization (ECM) type memristor. The advantages of promoting Ag dissolution and localizing cation diffusion region of AIST and DG layers can effectively suppress the well-known current overshoot issue and break the current-retention dilemma. Compared with its counterpart without buffer layer (Ag/a-C/Pt), the device with dual buffer layers (Ag/AIST/DG/a-C/Pt) presents excellent resistive switching (RS) performance, such as lower forming voltage with reduced overshoot current, smaller parameter fluctuations, and better cycling endurance. More importantly, the nonvolatile RS with low operation current of 10 μA and remarkable endurance (> 3.1 × 10
⁷
cycles) is realized, which is among the best of reported a-C-based ECM memories. Benefit from the low operation current, the device also shows the capacity of multilevel memory with six nonvolatile resistance states through regulating the compliance current.