Light‐Enhanced Negative Differential Resistance and Multi‐Level Resistive Switching in Glutamine‐Functionalized MoS₂ Quantum Dots for Resistive Random‐Access Memory Devices

Abstract Negative differential resistance (NDR) with multi‐level resistive switching has been investigated for realizing multi‐level memory devices. However, achieving a high peak‐to‐valley ratio of NDR is a formidable challenge for a reliable multi‐level switch. Here, a new type of a light‐enhanced NDR device accompanied with resistive switching based on glutamine‐functionalized MoS₂ quantum dots has been demonstrated. By increasing the illuminated light power on the device, the NDR effect can be greatly enhanced and a peak‐to‐valley ratio as high as 15.5 has been achieved. The tunneling transport and carrier trapping of the interface states are responsible for the mechanism of the light‐enhanced NDR. Multi‐level resistive switching can be realized in the same device by adjusting the illuminated light power. A high on/off resistance ratio of ≈10³ and good endurance in multi‐valued switching have been achieved, exhibiting potential applications in multi‐level memory devices.