Shmueli Shachar, Cohen Jungerman Mor, Shekhter Pini, Selzer Yoram
School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel.
The Tel Aviv Center for Nanoscience and Nanotechnology, Tel Aviv 69978, Israel.
J Phys Chem Lett. 2024 Oct 24;15(42):10602-10608. doi: 10.1021/acs.jpclett.4c02900. Epub 2024 Oct 15.
Molecular rectification is expected to be observed in metal-molecule-metal tunnel junctions in which the resonance levels responsible for their transport properties are spatially localized asymmetrically with respect to the leads. Yet, effects such as electrostatic screening and formation of metal induced gap states reduce the magnitude of rectification that can be realized in such junctions. Here we suggest that junctions of the form metal-molecule(s)-semimetal mitigate these interfacial effects. We report current rectification in junctions based on the semimetal bismuth (Bi) with high rectification ratios (>10) at 1.0 V using alkanethiols, molecules for which rectification has never been observed. In addition to the alleviation of screening and surface states, the efficient rectification is argued to be related to symmetry breaking of the applied bias in these junctions because of a built-in potential within the Bi lead. The significance of this built-in potential and its implications for the future and other applications are discussed.
分子整流有望在金属-分子-金属隧道结中被观测到，其中负责其输运性质的共振能级相对于引线在空间上不对称地局域化。然而，诸如静电屏蔽和金属诱导能隙态的形成等效应会降低在此类结中能够实现的整流幅度。在此，我们提出金属-分子（多个）-半金属形式的结可减轻这些界面效应。我们报道了基于半金属铋（Bi）的结中的电流整流，使用链烷硫醇时，在1.0 V下具有高整流比（>10），而此前从未观测到这些分子的整流现象。除了减轻屏蔽和表面态外，这种高效整流被认为与这些结中由于Bi引线内的内建电势导致的外加偏压对称性破缺有关。讨论了这种内建电势的重要性及其对未来和其他应用的影响。
