Electric-Field-Controllable Conductance Switching of an Overcrowded Ethylene Self-Assembled Monolayer

Abstract

Molecular isomerism has been discussed from the viewpoint of the tiniest switch and memory elements in electronics.Here, we report an overcrowded ethylene-based molecular conductance switch, which fulfills all the essential requirements for implementation into electronic devices, namely, electric-field-controllable reversible conductance change with a molecular-level spatial resolution, robust conformational bistability under ambient conditions, and ordered monolayer formation on electrode surfaces. The conformational state of this overcrowded ethylene, represented by a folded or twisted conformer, is susceptible to external environments. Nanoscopic measurements using scanning tunneling microscopy techniques, together with theoretical simulations, revealed the electronic properties of each conformer adsorbed on Au(111). While the twisted conformer prevails in the molecularly dispersed state, upon self-assembly into a monolayer, a two-dimensional network structure of the folded conformer is preferentially formed due to particular intermolecular interaction. In the monolayer state, folded-to-twisted and its reverse isomerization can be controlled by the modulation of electric fields.

From a bistable adsorbate to a switchable interface: tetrachloropyrazine on Pt(111)

“…Switchable interfaces in the literature rely on several function principles including modifying interactions at the interface 6 and applying external stimuli such as optical signals, 7,8 electric fields, 9,10 magnetic fields, 11 temperature, 12 biochemical processes, 13 or pH-value. 14 Here, we use temperature and pressure to switch adlayers of molecules that exhibit a double-well potential when adsorbing on a substrate.…”

Adsorption, Stretching, and Breaking Processes in Single‐Molecule Conductance of para‐Benzenedimethanethiol in Gold Nanogaps: A DFT‐NEGF Theoretical Study**

“…[3][4][5] Many novel phenomena of molecular electronics such as diode amplification, rectification, switching, quantum interference, ion sensing, and light-sensitive effects have been observed, [6][7][8][9][10][11] offering promising molecular electronic perspectives. To understand the electric properties of a single-molecule junction, which is the minimum functional unit, different techniques with high spatial resolution and fast response have been introduced [12][13][14] Widely used core experimental tools are scanning tunneling microscopy (STM), atomic force microscopy (AFM), and mechanically controllable break junctions (MCBJ). [15][16][17][18][19] In STM, the molecule is adsorbed between two metal electrodes, forming a metal tip-moleculesubstrate metal junction.…”

One molecule, two states: Single molecular switch on metallic electrodes

“…However, the co‐existed bistable states of the molecules would be randomly distributed on the surfaces based on Boltzmann statistics, 137 leading to noise signal and loss of memory functionality. Many attempts have been done to unify the molecular state, such as electric field 171 and tunneling carriers 159 . However, the switching probability decreases exponentially as molecule is located further way from the stimulus.…”