Interfacial Gap Switching in MXene Ti₃C₂T_x MoS₂ Memristors

Resistive-switching devices are essential building blocks for advanced multifunctional integrated circuits (ICs), with four major switching mechanisms (ion migration, phase change, magnetization orientation, and ferroelectric polarization) having been extensively studied, each facing inherent limitations for practical applications. Herein, we disclose an interfacial gap switching mechanism in a two-terminal Ti₃C₂T_x/MoS₂ device, fundamentally distinct from those conventional mechanisms. The switching mechanism relies on the interfacial gap modulation between the metallic MXene Ti₃C₂T_x layer and semiconducting MoS₂ layer under applied bias, leading to reversible switching between low resistance state and high resistance state. The gap modulation phenomenon was further observed in three-terminal transistor devices. The working principle takes advantage of MXene Ti₃C₂T_x with high concentration of negative charges, electrostatically interacting with MoS₂ triggered by bias or gating dynamically. Further optimization of memristor device exhibited ultra-low cycle-to-cycle variation, with a set voltage standard deviation of 40 mV and coefficient of variation of 2.31%, outperforming most reported 2D memristors. This discovery of gap modulation provides new insights into memristor device physics and offers a unique idea to build 2D memristor architecture for non-volatile memory related applications.