Yelin Tamar, Chakrabarti Sudipto, Vilan Ayelet, Tal Oren
Chemical and Biological Physics Department, Weizmann Institute of Science, 76100 Rehovot, Israel.
Nanoscale. 2021 Nov 18;13(44):18434-18440. doi: 10.1039/d1nr05680h.
In the field of molecular electronics, the interplay between molecular orientation and the resulting electronic transport is of central interest. At the single molecule level, this topic is extensively studied with the aid of break junction setups. In such experiments, two metal electrodes are brought into contact, and the conductance is typically measured when the electrodes are pulled apart in the presence of molecules, until a molecule bridges the two electrodes. However, the molecular junctions formed in this pull process reflect only part of the rich possible junction configurations. Here, we show that the push process, in which molecular junctions are formed by bringing the electrodes towards each other, allows the fabrication of molecular junction structures that are not necessarily formed in the pull process. We also find that in the extreme case, molecular junctions can be formed only in the push process that is typically ignored. Our findings demonstrate that tracking the two inverse processes of molecular junction formation, reveals a more comprehensive picture of the variety of molecular configurations in molecular junctions.
在分子电子学领域，分子取向与由此产生的电子传输之间的相互作用是核心研究内容。在单分子水平上，借助断结装置对这一主题进行了广泛研究。在这类实验中，将两个金属电极接触，并且通常在存在分子的情况下将电极拉开时测量电导，直到一个分子连接两个电极。然而，在这个拉伸过程中形成的分子结仅反映了丰富多样的可能结构型的一部分。在此，我们表明，通过使电极相互靠近而形成分子结的推压过程，能够制造出在拉伸过程中不一定形成的分子结结构。我们还发现，在极端情况下，分子结可能仅在通常被忽略的推压过程中形成。我们的研究结果表明，追踪分子结形成的两个相反过程，能够揭示分子结中各种分子构型的更全面情况。
