Zhang Rongjie, Chen Wenjun, Teng Changjiu, Liao Wugang, Liu Bilu, Cheng Hui-Ming
Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute and Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.
Sci Bull (Beijing). 2021 Aug 30;66(16):1634-1640. doi: 10.1016/j.scib.2021.04.025. Epub 2021 Apr 20.
The non-Markov process exists widely in thermodymanic process, while it usually requires the packing of many transistors and memories with great system complexity in a traditional device structure to minic such functions. Two-dimensional (2D) material-based resistive random access memory (RRAM) devices have the potential for next-generation computing systems with much-reduced complexity. Here, we achieve a non-Markov chain in an individual RRAM device based on 2D mineral material mica with a vertical metal/mica/metal structure. We find that the potassium ions (K) in 2D mica gradually move in the direction of the applied electric field, making the initially insulating mica conductive. The accumulation of K is changed by an electric field, and the 2D-mica RRAM has both single and double memory windows, a high on/off ratio, decent stability, and repeatability. This is the first time a non-Markov chain process has been established in a single RRAM, in which the movement of K is dependent on the stimulated voltage as well as their past states. This work not only uncovers an intrinsic inner ionic conductivity of 2D mica, but also opens the door for the production of such RRAM devices with numerous functions and applications.
非马尔可夫过程广泛存在于热力学过程中，而在传统器件结构中，通常需要大量晶体管和存储器的封装，系统复杂度极高才能实现类似功能。基于二维（2D）材料的电阻式随机存取存储器（RRAM）器件有望应用于复杂度大幅降低的下一代计算系统。在此，我们基于具有垂直金属/云母/金属结构的二维矿物材料云母，在单个RRAM器件中实现了非马尔可夫链。我们发现二维云母中的钾离子（K）逐渐沿外加电场方向移动，使原本绝缘的云母具有导电性。钾离子的积累受电场影响，二维云母RRAM具有单记忆窗口和双记忆窗口、高开/关比、良好的稳定性和可重复性。这是首次在单个RRAM中建立非马尔可夫链过程，其中钾离子的移动不仅取决于激励电压，还取决于其过去的状态。这项工作不仅揭示了二维云母固有的内部离子导电性，还为生产具有多种功能和应用的此类RRAM器件打开了大门。
