Surprisingly Big Rectification Ratios for a Very Small Unimolecular Rectifier

Abstract

To shrink electrical circuits beyond the looming practical limits of Moore's “Law”, it has been a common goal to create carbon‐based components. Here is the first example of a new class of donor–σ–acceptor rectifiers: hemibiquinones (HBQs). HBQs possess donor and acceptor moieties that are electronically isolated by inter‐ring torsion. A HBQ–dinitrile self‐assembles on a template‐stripped gold surface through directed chemisorption, forming a 1.1 nm‐thick monolayer. Rectification is measured through the monolayer or single molecules by using three different top electrode arrangements. Even though the HBQs are composed of relatively weak electrophores, rectification ratios ranging from 5 to 160 were observed at 2.5 V.

Ferrocenes as One-Electron Donors in Unimolecular Rectifiers

“…are used: this is sketched below and explained in detail in many The Aviram-Ratner proposal of unimolecular rectification [1] with two specific molecules suggested (1,2). Alabama (1997Alabama ( -2018 [7][8][9][10][11][12][13][14][15][16][17][18][19][20] [8,[21][22][23][24][25][26][27][28][29][30][31][32]. UME learned how inorganic metals couple (associate with or bond to) single organic molecules and how one can reliably exchange electrons and photons with these molecules.…”

“…Corrigenda for Ref. [8] A, yet is an excellent rectifier [20]. We have also seen that a strong, easily oxidized donor like tetramethyl-para-phenylenediamine in molecule 16 blocks the current across the monolayer between −0.5 and +0.5 Volts (Coulomb blockade) [18].…”

“…As of 2015, 53 unimolecular rectifiers had been measured worldwide [8], 15 of which at the UA (Figure 1, structures 4-18 [7][8][9][10][11][12][13][14][15][16][17][18][19][20]). Also, 169 molecular wires were measured around the world [8].…”

Molecular Diode Studies Based on a Highly Sensitive Molecular Measurement Technique

“…An electron-rich donor (D) electronically and spatially separated by an insulating bridge (σ) from an electron-poor acceptor (A) [44]. The electrical ground is shown; ( b ) Averaged 50 I–V s of the molecular junction in ( a ).…”

Rectification and negative differential resistance via orbital level pinning

“…In the field of molecular electronics, donor-acceptor systems have been widely explored for use as single-molecule diodes in accordance with the Aviram-Ratner ansatz 1 – 8 . Although the original ansatz was designed with molecular rectification in mind, the proposed charge transport mechanisms should also give rise to negative differential resistance (NDR) features similar to those seen in quantum double-well resonant tunnelling devices (dw-RTDs) 1 , 9 , 10 .…”