Development of Heteropolyvanadate Spin Clusters as Candidates for Future Redox-Based Memory Devices

在不久的将来，不断增加的量子尺寸效应将阻碍经典纳米电子器件特征尺寸的进一步缩小。为了保持摩尔定律的有效性，我建议首次将固态忆阻器的阻性开关的概念引入分子水平，并研究功能化的单个分子金属氧化物作为单分子存储器件。我的想法是通过在金属衬底(下电极)上沉积合适的氧化还原活性杂多钒酸盐(Hetero-POV)单分子，然后将其与扫描隧道显微镜(STM)的金属尖端(上电极)接触，来模拟典型阻性随机存取存储器(ReRAM)单元的简单金属-绝缘体-金属结构。这一原型装置将允许使用场来操纵氧化还原态，从而操纵吸附在表面上的单个杂化POV(IV/V)自旋团簇的价态依赖的电导率。SwitchSpinPOV是一项跨学科、极具探索性的项目，旨在利用具有不同稳定氧化还原状态的热稳定的异质POV单分子作为分子存储器件的原型，为电致电阻开关领域定义一个新的方向。电子离域、磁态、Kondo共振、氧化还原态和电导在单个杂化POV分子水平上的强相关性也为未来研究单个分子内量子信息的存储和处理开辟了广阔的前景。团簇溶液和固态反应性、热稳定性、电化学性质、光谱学、分子磁学和光物理特性的实验和计算结果将为单分子忆阻器关键参数的优化提供反馈。这也要求对异质POV的衬底沉积过程进行原子控制，以最终通过STM和扫描隧道光谱分析其电荷传输和氧化还原开关特性。

In the near future increasing quantum size effects will impede further reduction of the feature size of classical nanoelectronic devices. To keep Moore law valid, I propose adopting for the first time the concept of resistive switching of solid-state memristors to the molecular level and investigate functionalized individual molecular metal oxides as single-molecule memory devices. My idea is to simulate the simple Metal-Insulator-Metal structure of a typical Resistive Random Access Memory (ReRAM) cell by depositing an appropriate redox-active heteropolyvanadate (hetero-POV) single molecule on a metallic substrate (bottom electrode) and contact it then with the metallic tip (top electrode) of a scanning tunneling microscope (STM). This prototypal setup will allow using a field to manipulate the redox state and thereby the valence state-dependent conductivity of an individual hetero-POV(IV/V) spin cluster adsorbed on the surface. The cross-disciplinary and highly explorative project SwitchSpinPOV aims to define a new direction for the area of electrically-induced resistive switching using thermally stable hetero-POV single molecules with different stable redox states as prototypes for molecular memory devices. The strong correlation between the electron delocalization, magnetic state, Kondo resonance, redox state and electrical conductance on the level of a single hetero-POV molecule moreover opens up vast prospects for future investigations into the storage and processing of quantum information within one individual molecule. Experimental and computational results on the clusters solution and solid-state reactivity, thermostability, electrochemistry, spectroscopy, molecular magnetism and photophysics characteristics will provide feedback for optimization of the synthesis with regards to the critical parameters of the envisioned single-molecule memristor. This also mandates atomic control of substrate deposition processes of the hetero-POVs, to eventually enable analysis of their charge transport and redox switching properties via STM and scanning tunneling spectroscopy.