Electrically connected and plasmonically enhanced molecular junctions combine the optical functionalities of high field confinement and enhancement (cavity function), and of high radiative efficiency (antenna function) with the electrical functionalities of molecular transport. Such combined optical and electrical probes have proven useful for the fundamental understanding of metal–molecule contacts and contribute to the development of nanoscale optoelectronic devices including ultrafast electronics and nanosensors. Here, we employ a self-assembled metal–molecule–metal junction with a nanoparticle bridge to investigate correlated fluctuations in conductance and tunneling-induced light emission at room temperature. Despite the presence of hundreds of molecules in the junction, the electrical conductance and light emission are both highly sensitive to atomic-scale fluctuations─a phenomenology reminiscent of picocavities observed in Raman scattering and of luminescence blinking from photoexcited plasmonic junctions. Discrete steps in conductance associated with fluctuating emission intensities through the multiple plasmonic modes of the junction are consistent with a finite number of randomly localized, point-like sources dominating the optoelectronic response. Contrasting with these microscopic fluctuations, the overall plasmonic and electronic functionalities of our devices feature long-term survival at room temperature and under an electrical bias of a few volts, allowing for measurements over several months.

中文翻译：

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电驱动和等离激元增强分子结中的光发射和电导波动


电连接和等离子体增强的分子结将高场限制和增强（腔功能）以及高辐射效率（天线功能）的光学功能与分子传输的电功能结合起来。事实证明，这种组合的光学和电学探针对于从根本上理解金属分子接触非常有用，并有助于开发包括超快电子器件和纳米传感器在内的纳米级光电器件。在这里，我们采用带有纳米颗粒桥的自组装金属-分子-金属结来研究室温下电导和隧道诱导光发射的相关波动。尽管连接处存在数百个分子，但电导和光发射都对原子尺度的波动高度敏感——这种现象让人想起拉曼散射中观察到的皮空腔和光激发等离子体连接处的发光闪烁。与通过结的多种等离子体模式的波动发射强度相关的电导的离散阶跃与主导光电响应的有限数量的随机局部点状源一致。与这些微观波动相比，我们设备的整体等离子体和电子功能具有在室温和几伏电偏压下长期存活的特点，允许进行几个月的测量。