Study On The High-uniformity And Self-rectifying Resistive Random Access Memory Based On MXene-TiO₂ Schottky Junction

Metal-oxide junction is one of the most basic building blocks for practical electronic devices.Generally speaking,a Schottky barrier is formed at the metaloxide interface due to the difference between metal work function and the oxide electron affinity.Recently,resistive random access memory(RRAM)devices based on metal-oxide Schottky junctions have been increasingly recognized as a mainstream technology to meet the requirements of the rapid development of non-volatile data storage,logic operation and neural computing due to their simple configuration and high reproducibility.However,an inevitable variability should be the primary obstacle for RRAMs due to the stochastic nature of the filamentary resistive switching mechanism.Therefore,seeking a resistive switching mechanism that could eliminate the involvement of the prominent local conductive filamentary is impending for the development of uniform RRAM devices.Another acknowledged resistive switching mechanism is the field-induced modulation of Schottky barrier profile,which usually occurs on the entire interface between the electrode and oxide to improve the uniformity.Recently,as the wafer-scale MXene film patterning with high-resolution has been realized,it opens new avenues for designing highly active and long-life electrode candidates for RRAM devices due to its excellent metallic conductivity and good hydrophilicity.In general,during the preparation of MXene materials,the etching process of hydrofluoric acid will inevitably introduce numerous defects into MXene,which makes MXene an ideal candidate for building uniform RRAM devices.Here,we report a uniform RRAM device with MXene-TiO2 Schottky junction,while MXene and TiO2 are used as the top electrode and resistive layer,respectively.The resistive switching behavior comes from the electrical modulation of barrier profile of MXene-TiO2 Schottky junction,that is,the charge carriers injected from the MXene top-electrode can be trapped by charge traps in the MXene-TiO2 interface to form a space charge to modulate the barriers.As a result,our device exhibits the uniformity of current on-off ratio,device-to-device reproducibility,long-term retention and reliable endurance.Moreover,by replacing the bottom electrode with silicon,a self-rectifying behavior can be obtained with a high self-rectifying ratio due to the difference of the Schottky barrier height at the high resistance state.