The dielectric behavior of organic materials at molecular dimensions can be vastly different than their bulk counterparts and therefore it is important to investigate and control the dielectric response of molecular-scale materials for a large variety of applications. Large-area molecular junctions are explored to study the charge transport mechanisms with unprecedented detail and to demonstrate novel functionalities. Therefore, large-area molecular junctions are, in principle, a promising platform to study the dielectric effects at the molecular scale. This review summarizes recent progress on the measurements and understanding of the dielectric behavior of molecular systems and how they behave differently from their bulk properties. This review introduces, briefly, the concepts of impedance spectroscopy (IS) and how this technique can be applied to study the dielectric response of solid-state large-area molecular junctions. This analysis gives new insights in the factors that determine the dielectric constant of monolayers (including collective electrostatic effects and how the dielectric constant increases with monolayer thickness), how IS gives new insights into the role of defects, and the factors that contribute to the molecule–electrode contact resistance. This review ends with an outlook highlighting interesting future directions.

中文翻译：

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阻抗谱探测大面积分子隧道结的异常介电响应

有机材料在分子维度上的介电行为可能与其体对应物大不相同，因此研究和控制分子尺度材料的介电响应对于各种应用非常重要。探索大面积分子结，以前所未有的细节研究电荷传输机制并展示新的功能。因此，原则上，大面积分子结是研究分子尺度介电效应的有前途的平台。这篇综述总结了最近在测量和理解分子系统的介电行为方面取得的进展，以及它们的行为与体积特性有何不同。这篇综述简要介绍了，阻抗谱 (IS) 的概念以及该技术如何应用​​于研究固态大面积分子结的介电响应。该分析对决定单层介电常数的因素（包括集体静电效应以及介电常数如何随单层厚度增加）、IS 如何对缺陷的作用以及影响分子的因素提供了新的见解——电极接触电阻。这篇评论以突出有趣的未来方向的展望结束。该分析对决定单层介电常数的因素（包括集体静电效应以及介电常数如何随单层厚度增加）、IS 如何对缺陷的作用以及影响分子的因素提供了新的见解——电极接触电阻。这篇评论以突出有趣的未来方向的展望结束。该分析对决定单层介电常数的因素（包括集体静电效应以及介电常数如何随单层厚度增加）、IS 如何对缺陷的作用以及影响分子的因素提供了新的见解——电极接触电阻。这篇评论以突出有趣的未来方向的展望结束。