Organic materials show promise as switching layers for resistive random access memory (RRAM). However, practical application has been limited by inefficient charge injection and transport in typical organic materials. This study proves that local enhancement of electric fields through structured electrodes can improve charge injection and transport in organic RRAM. Specifically, pyramid-structured electrodes with an extremely sharp tip are introduced into RRAM with a polyimide (PI) switching layer. The electric field in the pyramid-structured RRAM can be significantly enhanced only at the tip, thereby facilitating charge injection at the electrode/PI interface and charge transport through the PI switching layer. Indeed, the resulting RRAM exhibits low and reliable operating voltages (SET: 1.76 V ± 0.41 V / RESET: −0.49 V ± 0.15 V) compared with conventional PI-based RRAMs with planar electrodes. The conductive path formed in the tip region is observed directly using conductive atomic force microscopy, demonstrating that resistive switching occurs by tip-enhanced electric fields. Also, the charge transport mechanism follows the space charge-limiting current model modified by the Poole–Frenkel effect. These results provide an effective strategy to control the charge concentration, injection, and transport in organic RRAM, for realization of low-cost, large-area, shape-deformable data storage devices.

有机材料有望作为电阻式随机存取存储器（RRAM）的开关层。但是，实际应用受到典型有机材料中电荷注入和传输效率低下的限制。这项研究证明通过结构化电极局部增强电场可以改善有机RRAM中的电荷注入和传输。具体地，将具有极尖的尖端的金字塔结构的电极引入具有聚酰亚胺（PI）切换层的RRAM中。仅在尖端，可以显着增强金字塔结构RRAM中的电场，从而有利于电极/ PI界面处的电荷注入以及通过PI开关层的电荷传输。实际上，所得的RRAM表现出低而可靠的工作电压（SET：1.76  V 与传统的带有平面电极的基于PI的RRAM相比，具有 ±0.41 V / RESET：−0.49  V ±0.15 V）。使用导电原子力显微镜直接观察在尖端区域中形成的导电路径，表明通过尖端增强的电场发生了电阻切换。同样，电荷传输机制遵循由Poole-Frenkel效应修正的空间电荷限制电流模型。这些结果提供了一种有效的策略来控制有机RRAM中的电荷浓度，注入和传输，从而实现低成本，大面积，可变形的数据存储设备。