Real-time in situ optical tracking of oxygen vacancy migration in memristors
Real-time in situ optical tracking of oxygen vacancy migration in memristors
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DOI：
10.1038/s41928-020-00478-5
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发表时间：
2020-10-05
影响因子：
34.3
通讯作者：
Baumberg, Jeremy J.
中科院分区：
文献类型：
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作者：
Di Martino, Giuliana;Demetriadou, Angela;Baumberg, Jeremy J.
电阻开关，也称为忆阻器，是低功耗、纳秒响应器件，用于一系列以内存为中心的技术。在外部施加电势的驱动下，价变阻变存储器的切换机制涉及介电介质内氧空位的迁移、积累和重新排列，从而导致电导率的变化。观察这些设备内部并了解形态变化如何表征其功能的能力对于它们的发展至关重要。然而，当前的技术往往具有破坏性和侵入性。在这里，我们报告了一种无损光学光谱技术，可以以纳米级的灵敏度检测数百个氧空位的运动。电阻开关以纳米颗粒镜面几何形状排列，以利用对开关材料内紧密限制的等离子体热点中发生的形态变化的高光学敏感性。使用这种方法，我们发现钛酸锶忆阻器薄膜表面形成纳米级氧气泡，最终导致器件在循环时击穿。
Resistive switches, which are also known as memristors, are low-power, nanosecond-response devices that are used in a range of memory-centric technologies. Driven by an externally applied potential, the switching mechanism of valence change resistive memories involves the migration, accumulation and rearrangement of oxygen vacancies within a dielectric medium, leading to a change in electrical conductivity. The ability to look inside these devices and understand how morphological changes characterize their function has been vital in their development. However, current technologies are often destructive and invasive. Here, we report a non-destructive optical spectroscopy technique that can detect the motion of a few hundred oxygen vacancies with nanometre-scale sensitivity. Resistive switches are arranged in a nanoparticle-on-mirror geometry to exploit the high optical sensitivity to morphological changes occurring in tightly confined plasmonic hotspots within the switching material. Using this approach, we find that nanoscale oxygen bubbles form at the surface of a strontium titanate memristor film, leading ultimately to device breakdown on cycling.