Department of Mechanical and Industrial Engineering, ‡Polymer Science and Engineering Department, and §Department of Chemistry, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States.
ACS Appl Mater Interfaces. 2017 Mar 29;9(12):10847-10854. doi: 10.1021/acsami.7b00220. Epub 2017 Mar 16.
Memristors, often comprising an insulating metal oxide film between two metal electrodes (MIM), constitute a class of two-terminal devices that possesses tunable variations in resistance based on the applied bias history. Intense research remains focused on the metal-insulator interface, which serves as the crux of coupled electronic-ionic interactions and dictates the underpinning transport mechanisms at either electrode. Top-down, ultrahigh-vacuum (UVH) deposition approaches for MIM nanostructures yield highly crystalline, heteroepitaxial interfaces but limit the number of electrode configurations due to a fixed bottom electrode. Here we report on the convective self-assembly, removal, and transfer of individual nanoribbons comprising solution-processed, single-crystalline strontium titanate (STO) perovskite oxide nanocrystals to arbitrary metallized substrates. Nanoribbon transferability enables changes in transport models ranging from interfacial trap-detrap to electrochemical metallization processes. We also demonstrate the endurance of memristive behavior, including switching ratios up to 10, after nanoribbon redeposition onto poly(ethylene terephthalate) (PET) flexible substrates. The combination of ambient, aerobic prepared nanocrystals and convective self-assembly deposition herein provides a pathway for facile, scalable manufacturing of high quality, functional oxide nanostructures on arbitrary surfaces and topologies.
忆阻器通常由两个金属电极(MIM)之间的绝缘金属氧化物薄膜组成,属于一种具有可调电阻变化的两端器件,其电阻变化基于所施加的偏置历史。目前,研究的重点仍然集中在金属-绝缘体界面上,该界面是电子-离子耦合相互作用的关键所在,决定了两个电极的基础传输机制。自上而下的超高真空(UVH)沉积方法可用于制备 MIM 纳米结构,得到的界面具有高度的结晶性和异质外延性,但由于固定的底部电极,限制了电极结构的数量。在这里,我们报告了通过对流自组装、去除和转移单个纳米带的方法,这些纳米带由溶液处理的、单晶钛酸锶(STO)钙钛矿氧化物纳米晶体组成,可以转移到任意金属化基底上。纳米带的可转移性使传输模型从界面陷阱脱陷转变为电化学金属化过程,从而发生变化。我们还证明了忆阻行为的耐久性,包括在将纳米带重新沉积到聚对苯二甲酸乙二醇酯(PET)柔性基底上后,其开关比高达 10。这里所采用的常压、有氧制备的纳米晶体和对流自组装沉积相结合,为在任意表面和拓扑结构上制造高质量、功能化的氧化物纳米结构提供了一种简便、可扩展的方法。