Gate-tunable memristors from monolayer MoS2

We report here gate-tunable memristors based on monolayer MoS
₂
grown by chemical vapor deposition (CVD). These memristors are fabricated in a field-effect geometry with the channel consisting of polycrystalline MoS
₂
films with grain sizes of 3-5 p.m. The device characteristics show switching ratios up to ~500, with the resistance in individual states being continuously gate-tunable by over three orders of magnitude. The resistive switching results from dynamically varying threshold voltage and Schottky barrier heights, whose underlying physical mechanism appears to be vacancy migration and/or charge trapping. Top-gated devices achieve reversible tuning of threshold voltage, with potential utility in non-volatile memory or neuromorphic architectures.