Controlled Hysteresis of Conductance in Molecular Tunneling Junctions
Controlled Hysteresis of Conductance in Molecular Tunneling Junctions
复制标题
分子隧道连接中电导的受控滞后
DOI：
10.1021/acsnano.1c10155
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发表时间：
2022
期刊：
影响因子：
17.1
通讯作者：
Whitesides, George M.
中科院分区：
文献类型：
--
作者：
Park, Junwoo;Kodaimati, Mohamad S.;Belding, Lee;Root, Samuel E.;Schatz, George C.;Whitesides, George M.
本文解决的问题是由EGaIn电极和以螯合物（与2，2 ′-联吡啶络合的过渡金属二氯化物; BIPY-MCl 2）为末端的烷硫醇盐自组装单分子膜制成的双末端分子结中滞后行为的起源。由这些BIPY-MCl 2结显示的电导滞后的大小取决于金属离子（M）的身份和跨结施加的电压的窗口。滞后行为的电导在这些结中只出现在一个不相干的（福勒-诺德海姆）隧穿制度。当络合的金属离子是Mn（II）、Fe（II）、Co（II）或Ni（II）时，在+1.0 V和−1.0 V之间的电压范围内观察到非相干隧穿和滞后。然而，当金属离子是Cr（II）或Cu（II）时，只观察到共振（一步）隧穿，并且结没有表现出滞后，并且不进入非相干隧穿状态。利用这种关系，可以控制BIPY-MCl 2结的电导特性。这种电压诱导的电导变化证明了一种简单、快速和可逆的方式（即，通过改变施加的电压）来调制分子隧道结中的电导。
The problem this paper addresses is the origin of the hysteretic behavior in two-terminal molecular junctions made from an EGaIn electrode and self-assembled monolayers of alkanethiolates terminated in chelates (transition metal dichlorides complexed with 2,2′-bipyridine; BIPY-MCl2). The hysteresis of conductance displayed by these BIPY-MCl2junctions changes in magnitude depending on the identity of the metal ion (M) and the window of the applied voltage across the junction. The hysteretic behavior of conductance in these junctions appears only in an incoherent (Fowler–Nordheim) tunneling regime. When the complexed metal ion is Mn(II), Fe(II), Co(II), or Ni(II), both incoherent tunneling and hysteresis are observed for a voltage range between +1.0 V and −1.0 V. When the metal ion is Cr(II) or Cu(II), however, only resonant (one-step) tunneling is observed, and the junctions exhibit no hysteresis and do not enter the incoherent tunneling regime. Using this correlation, the conductance characteristics of BIPY-MCl2junctions can be controlled. This voltage-induced change of conductance demonstrates a simple, fast, and reversible way (i.e., by changing the applied voltage) to modulate conductance in molecular tunneling junctions.