Advance of Mechanically Controllable Break Junction for Molecular Electronics

Abstract

Molecular electronics stands for the ultimate size of functional elements, keeping up with an unstoppable trend over the past few decades. As a vital component of molecular electronics, single molecular junctions have attracted significant attention from research groups all over the world. Due to its pronounced superiority, the mechanically controllable break junctions (MCBJ) technique has been widely applied to characterize the dynamic performance of single molecular junctions. This review presents a system analysis for single-molecule junctions and offers an overview of four test-beds for single-molecule junctions, thus offering more insight into the mechanisms of electron transport. We mainly focus on the development of state-of-the-art mechanically controlled break junctions. The three-terminal gated MCBJ approaches are introduced to manipulate the electron transport of molecules, and MCBJs are combined with characterization techniques. Additionally, applications of MCBJs and remarkable properties of single molecules are addressed. Finally, the challenges and perspective for the mechanically controllable break junctions technique are provided.

A Magic Ratio Rule for Beginners: A Chemist's Guide to Quantum Interference in Molecules

“…For the purpose of attaching molecules to different types of electrodes, the ends of the molecule should be terminated by “anchor groups”, which bind opposite ends of the molecule to the source and drain electrodes. Over the last two decades, a variety of anchor groups have been explored ,. For instance, thiols, pyridines, amines, methyl sulfides and direct gold–carbon bonds have been utilised in metal–molecule–metal junctions.…”

Large Conductance Variations in a Mechanosensitive Single-Molecule Junction

“… 3 , 4 The steady refinement of the break-junction technique also allowed to study correlations between mechanical manipulations and transport features at the single-molecule level in a systematic way. 5 Examples include binary switching through mechanical control of the metal–molecule contact geometry 6 or through stereoelectronic effects, 7 mechanical-stress-sensitive redox chromophores, 8 and coordination compounds that show spin-state switching under mechanical stress. 9 Furthermore, the sensitivity of the technique makes it possible to observe intermolecular behaviors such as π-stacking, 10 , 11 and more recently, the interdependence of conductance and frontier orbitals involved in the π-stacking 12 , 13 could be directly demonstrated.…”

Application of Micro/Nanofabrication Techniques to On‐Chip Molecular Electronics

“…Several approaches have been reported to integrate a gate electrode in MCBJ devices, based on either a back gate or a side gate, as detailed below. [ 1,22,37,43,70–72 ]…”