The film quality of insulators significantly affects performance of resistive random‐access memories (RRAMs), particularly in current leakage and degradation. In this study, a facile and practical method is employed to achieve the van der Waals epitaxy of bismuth iodide (BiI₃) on silicon by using a self‐assembled monolayer of octadecyltrichlorosilane (OTS) as a buffer layer. The BiI₃ layer is compact and has high crystallinity, a pinhole‐free, and compact surface; every BiI₃ crystal is horizontally aligned with OTS–Si substrate. The RRAMs with the Si⁺⁺/OTS/BiI₃/Au structure exhibit excellent resistive switching properties with a very high on/off ratio of 10⁹, long‐term stability for data retention, high endurance in write–erase cycles, and multistate information storage capacity. The crystal orientation, anisotropic carrier transport, morphology, deposition rate, and roughness considerably influence the resistive switching results. These are thoroughly investigated by analyzing the current–voltage characteristics at various temperatures, scanning electron microscope, atomic force microscope, X‐ray photoemission spectroscopy, and X‐ray diffraction patterns. It is proposed that the resistive switching mechanisms is caused by the iodine ion migration, which changes the valence charge of bismuth. This leaves a partially formed conductive metallic bismuth filament in the BiI₃ layer under the electrical field that enables multistate data storage.

中文翻译：

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具有多状态数据存储的非易失性电阻切换存储器的水平取向碘化铋/硅异质结构的范德华外延

绝缘体的膜质量会显着影响电阻式随机存取存储器（RRAM）的性能，特别是在电流泄漏和退化方面。在这项研究中，通过使用十八烷基三氯硅烷（OTS）的自组装单层作为缓冲层，采用一种简便实用的方法实现硅上碘化铋（BiI ₃）的范德华外延。BiI ₃层致密且具有高结晶度，无针孔且表面致密；每个BiI ₃晶体都与OTS-Si衬底水平对准。具有Si ⁺⁺ / OTS / BiI ₃ / Au结构的RRAM具有出色的电阻切换特性，其开/关比非常高，为10 ⁹，数据保留的长期稳定性，写擦除周期的高耐久性以及多状态信息存储容量。晶体取向，各向异性载流子传输，形态，沉积速率和粗糙度会极大地影响电阻转换结果。通过分析各种温度下的电流-电压特性，扫描电子显微镜，原子力显微镜，X射线光电子能谱和X射线衍射图对这些进行了彻底的研究。提出了电阻开关机制是由碘离子迁移引起的，碘离子迁移改变了铋的化合价。这在电场下的BiI ₃层中留下了部分形成的导电金属铋灯丝，可实现多态数据存储。