Lee Junyong, Song Woochan, Kwak Hyunjeong, Kim Seyoung
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
Small. 2025 Jul;21(30):e2504071. doi: 10.1002/smll.202504071. Epub 2025 Jun 23.
Electrochemical random-access memory (ECRAM) devices are promising synaptic elements for neuromorphic computing due to their uniform and tunable programmability. However, despite growing interest in ECRAM devices, studies have primarily focused on devices with amorphous or polycrystalline tungsten oxide (WO) films, leaving the impact of single-crystalline materials in oxygen-based ECRAMs largely unexplored. This work reports the first realization of single-crystalline hexagonal tungsten oxide (h-WO) nanowire (NW) based ECRAM device. Leveraging the high crystallinity and distinct atomic structure of h-WO NWs, the device exhibits significantly enhanced symmetry in conductance modulation, a key metric for synaptic emulation. More strikingly, a novel lateral switching mode emerges under specific configurations, accompanied by an unexpected conductance surge during relaxation, resembling neuronal integration and activation functions. A mechanism attributed to the electrode-NW interface properties is proposed to explain this behavior. These findings not only reveal a previously unexplored aspect of ECRAM switching physics, but also expand the functional potential of ECRAMs through fundamental material innovation.
电化学随机存取存储器（ECRAM）器件因其均匀且可调的可编程性，是用于神经形态计算的有前途的突触元件。然而，尽管对ECRAM器件的兴趣日益浓厚，但研究主要集中在具有非晶或多晶氧化钨（WO）薄膜的器件上，基于氧的ECRAM中单晶材料的影响在很大程度上尚未得到探索。这项工作报道了首个基于单晶六方氧化钨（h-WO）纳米线（NW）的ECRAM器件的实现。利用h-WO NWs的高结晶度和独特的原子结构，该器件在电导调制方面表现出显著增强的对称性，这是突触模拟的一个关键指标。更引人注目的是，在特定配置下出现了一种新颖的横向开关模式，在弛豫过程中伴随着意外的电导激增，类似于神经元的整合和激活功能。提出了一种归因于电极-NW界面特性的机制来解释这种行为。这些发现不仅揭示了ECRAM开关物理中一个以前未被探索的方面，而且通过基础材料创新扩展了ECRAM的功能潜力。
