标题： 金/自组装单层/单个银纳米立方体分子结中二茂铁与等离子体相互作用的动态切换 显示英文标题

标题： Dynamic switching of ferrocene and plasmonic interactions in Au/self-assembled monolayer/single Ag nanocube molecular junctions

摘要： 我们报告了嵌入在由点击化学自组装单层的二茂铁基烷基硫醇在超平坦金表面上制成的双隧道屏障等离子体腔中的二茂铁基团的氧化还原切换，连接到一个由聚乙烯吡咯烷酮封端的银纳米立方体AgNC，该纳米立方体通过导电AFM探针接触，以研究在暗处和等离子体共振波长下的光照射下的电子传输特性。 我们在暗处观察到电流-电压（I-V）特性中的双重行为：在正电压下有大的滞后回路，在负电压下有滞后的负微分电导（NDC），这是由于二茂铁在其氧化状态（Fc+）和中性状态（Fc0）之间的氧化还原切换所致。 I-V曲线通过广义的联合Marcus-Landauer模型进行分析。 我们确定了Fc+和Fc0状态的最高占据分子轨道分别位于费米能级以下0.54和0.42 eV，切换时的弱重组能小于0.1 eV。 在等离子体激发下，滞后和NDC行为不再出现，Au-二茂铁基烷基硫醇/AgNC结的I-V特性变得类似于Au-二茂铁基烷基硫醇SAM。 由于等离子体诱导的耦合（快速电子转移）在二茂铁的两个氧化还原状态之间产生的虚拟分子轨道位于0.46 eV。 这种动态行为为人工突触器件在神经形态计算中的应用提供了前景，并且可以通过光按需开启或关闭这种突触行为。 显示英文摘要

摘要： We report the redox switching of ferrocene moieties embedded in a double tunnel barrier plasmonic cavity fabricated from a click-chemistry self-assembled monolayers of ferrocenyl-alkylthiol on ultra flat gold surfaces, connected to a single poly(vinylpyrrolidone) capped silver nanocube, AgNC, which is contacted by the tip of a conductive-AFM to study the electron transport properties in the dark and under light irradiation at the plasmonic resonance wavelengths. We observe a dual behavior in the current-voltage (I-V) characteristics in the dark: a large hysteresis loop at positive voltages and an hysteretic negative differential conductance (NDC) at negative voltages, due to the redox switching of ferrocene between its oxidized (Fc+) and neutral (Fc0) states. The I-V curves are analyzed by a generalized combined Marcus-Landauer model. We determine the highest occupied molecular orbital of the Fc+ and Fc0 states at 0.54 and 0.42 eV below the Fermi energy, respectively, with a weak reorganization energy < 0.1 eV upon switching. Under plasmonic excitation, the hysteresis and NDC behaviors are no longer observed and the I-V characteristics of the Au-ferrocenyl-alkylthiol/AgNC junctions become similar to Au-ferrocenyl-alkylthiol SAMs. A virtual molecular orbital due to the plasmon-induced coupling (fast electron transfer) between the two redox states of the Fc is determined at 0.46 eV. This dynamic behavior opens perspectives in artificial synaptic devices for neuromorphic computing with the additional function to turn on/off this synaptic behavior on-demand by light.