Hu Wenjie, Fan Zhen, Mo Linyuan, Lin Haipeng, Li Meixia, Li Wenjie, Ou Jiali, Tao Ruiqiang, Tian Guo, Qin Minghui, Zeng Min, Lu Xubing, Zhou Guofu, Gao Xingsen, Liu Jun-Ming
Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China.
ACS Appl Mater Interfaces. 2025 Feb 12;17(6):9595-9605. doi: 10.1021/acsami.4c19627. Epub 2025 Jan 30.
SrFeO (SFO) offers a topotactic phase transformation between an insulating brownmillerite SrFeO (BM-SFO) phase and a conductive perovskite SrFeO (PV-SFO) phase, making it a competitive candidate for use in resistive memory and neuromorphic computing. However, most of existing SFO-based memristors are nonvolatile devices which struggle to achieve short-term synaptic plasticity (STP). To address this issue and realize STP, we propose to leverage ferroelectric polarization to effectively draw ions across the interface so that the PV-SFO conductive filaments (CFs) can be ruptured in absence of an external field. As a proof of concept, we fabricate ferroelectric Pb(ZrTi)O (PZT)/BM-SFO bilayer films with Au top electrodes and SrRuO bottom electrodes. The device exhibits the desired volatile resistive switching behavior, with its low resistance state decaying over time. Such volatility is attributed to the positive polarization charge near the PZT/SFO interface, which can attract the oxygen ions from SFO to PZT and hence lead to the rupture of CFs. Moreover, this volatile device successfully emulates STP-related synaptic functions, including excitatory postsynaptic current, paired-pulse facilitation, learning-experience behavior, associative learning, and reservoir computing. Our study showcases an effective method for achieving volatile resistive switching and STP, which may be applied to various systems beyond SFO-based memristors.
SrFeO（SFO）在绝缘的钙钛矿褐铁矿SrFeO（BM-SFO）相和导电的钙钛矿SrFeO（PV-SFO）相之间提供了一种拓扑相变，使其成为电阻式存储器和神经形态计算中有竞争力的候选材料。然而，现有的大多数基于SFO的忆阻器都是非易失性器件，难以实现短期突触可塑性（STP）。为了解决这个问题并实现STP，我们建议利用铁电极化有效地吸引离子穿过界面，以便在没有外部电场的情况下使PV-SFO导电细丝（CFs）断裂。作为概念验证，我们制备了具有金顶电极和SrRuO底电极的铁电Pb（ZrTi）O（PZT）/BM-SFO双层膜。该器件表现出所需的挥发性电阻开关行为，其低电阻状态随时间衰减。这种挥发性归因于PZT/SFO界面附近的正极化电荷，它可以吸引来自SFO的氧离子到PZT，从而导致CFs的断裂。此外，这种挥发性器件成功地模拟了与STP相关的突触功能，包括兴奋性突触后电流、双脉冲易化、学习经验行为、联想学习和储层计算。我们的研究展示了一种实现挥发性电阻开关和STP的有效方法，该方法可能应用于基于SFO的忆阻器之外的各种系统。
