二维材料阻变存储器微观工作机制及性能调控的原位透射电镜研究

鉴于阻变存储器（RRAM）在器件性能、可靠性、集成及环境适应性等方面的问题，对阻变材料的探索设计至关重要。二维材料由于具有原子层厚度、多型性及优异的物理特性而在提升RRAM空间存储密度，降低功耗，优化界面性质及拓展应用领域等方面具有广阔前景。虽然二维材料RRAM的阻变特性已逐渐受到研究关注，但目前其微观工作机理和影响器件结构优化的介观物理机制还不明晰，对其阻变参数均一性和可靠性的深入研究及改善方法仍较欠缺。针对该问题，本项目拟借助原位电子显微学技术，在透射电镜中基于几种典型二维材料构筑RRAM原型器件，在阻变特性测量过程中对不同来源导电细丝形成与断开的动力学过程进行观测，阐明其电阻转变的微观机制；探索二维材料组分及缺陷等结构参数对阻变机制及性能的调控规律；揭示外场（电场及温度）作用下二维材料及其与金属界面结构的稳定性。本项目的开展有望为二维材料RRAM研发及性能改善提供实验支持。

Given the fundamental problems faced by resistive random access memories (RRAM) in device performance, reliability, integration and environmental adaptability, the exploration and design of resistive switching materials is quite important. Due to their atomic thickness, polymorphs and good physical properties, two-dimensional (2D) materials are quite promising in improving the spatial storage density, lowering power consumption, optimizing interfacial property and expanding the application fields of RRAM. Although the resistive switching properties of 2D materials-based RRAM have gradually attracted research attention, the microscopic working mechanisms and the mesoscopic physical mechanisms of factors influencing the device structure optimization remain unclear. Moreover, there still lacks further investigation and improvement methods on the uniformity and reliability of their resistive switching parameters. To this end, taking advantage of in-situ electron microscopy technique, the dynamic formation and fracture process of the conductive filaments formed by various sources will be directly observed in the transmission electron microscope during the resistive switching property measurement of several typical 2D materials-based RRAM, thus the microscopic mechanism of the resistive switching behavior of 2D materials can be clarified. Furthermore, the modulation of structural parameters like chemical compositions and defects on the resistive switching mechanism and performance will be summarized. Finally, the stability of the interface between 2D materials and metallic electrodes under external fields (electric filed and temperature) will also be revealed. This project is promising in providing important experimental support for the design, development and performance improvement of 2D material-based RRAM.