Fabrication of metallic and non-metallic top electrodes for large-area molecular junctions

Abstract

Molecular junctions have proven invaluable tools through which to explore the electronic properties of molecules and molecular monolayers. In seeking to develop a viable molecular electronics based technology it becomes...

The syntheses, structures and spectroelectrochemical properties of 6-oxo-verdazyl derivatives bearing surface anchoring groups

“…The orbital topologies of the model systems [B] +/0/À and [C] +/0/À also deserve comment in the wider context of the use of such compounds as components within molecular electronic junctions. 59,60 The structure of the HOMO and LUMO is known to influence molecular conductance, and recently highlighted orbital product rules serve as tools for discovery of quantum interference phenomena. [61][62][63] In brief, the rules provide a qualitative indication for the presence (or absence) of destructive quantum interference (DQI) features in the transmission function, T(E), from the relative phases of the HOMO and LUMO at the site of contact to the electrodes.…”

Experimental Validation of Quantum Circuit Rules in Molecular Junctions

“…Beyond junctions based on 'large area' contacts to large numbers of molecules in well ordered monolayers, [8][9][10][11] the development of techniques for the formation of single-molecule junctions such as the scanning tunnelling microscope break junction (STM-BJ), [12] current-distance spectroscopy (I(s)), [13] and mechanically controlled break-junctions (MCBJ) [14] have become essential experimental tools through which to probe the electrical properties and physical structure of molecular junctions in unprecedented detail. Through such studies, molecules that integrate within a junction to give electrical responses that correspond to wires, rectifiers, and switches have been developed, [15,16] while the introduction of a third 'gate' electrode to the junction assembly has allowed the demonstration of a transistor-like response at the single-molecule level.…”

Uncapped Gold Nanoparticles for the Metallization of Organic Monolayers

“…However, one of the main bottlenecks to be addressed en route to true large‐area molecular electronic junctions is the development of methodologies that permit top electrodes to be reliably fabricated onto the functional monolayer. [ 30–36 ]…”

“…These problems include penetration of high‐energy metal atoms through the monolayer during the deposition process resulting in short‐circuits and/or damage of the functional organic molecules in the monolayer, and low surface coverage of the monolayer by the top‐contact electrode. [ 30–36 ] Whilst the use of liquid materials as top contacts alleviates some of these issues, a liquid contact would force the use of encapsulation techniques that may not be compatible with large‐scale fabrication whilst also being reliant on toxic (Hg) or scarce (e‐GaIn) materials. The use of electron‐beam deposited carbon electrodes has met with great success in the fabrication of molecular junctions from robust molecular layers, but the nature of the equipment involved means that this technique is not readily accessible in many laboratories.…”