The merger of electrochemistry and molecular electronics

Abstract

Molecular Electronics has the potential to greatly enhance existing silicon-based microelectronics to realize new functions, higher device density, lower power consumption, and lower cost. Although the investigation of electron transport through single molecules and molecular monolayers in "molecular junctions" is a recent development, many of the relevant concepts and phenomena are derived from electrochemistry, as practiced for the past several decades. The past 10+ years have seen an explosion of research activity directed toward how the structure of molecules affects electron transport in molecular junctions, with the ultimate objective of "rational design" of molecular components with new electronic functions, such as chemical sensing, interactions with light, and low-cost, low-power consumer electronics. In order to achieve these scientifically and commercially important objectives, the factors controlling charge transport in molecules "connected" to conducting contacts must be understood, and methods for massively parallel manufacturing of molecular circuits must be developed. This Personal Account describes the development of reproducible and robust molecular electronic devices, starting with modified electrodes used in electrochemistry and progressing to manufacturable molecular junctions. Although the field faced some early difficulties in reliability and characterization, the pieces are now in place for rapid advances in understanding charge transport at the molecular level. Inherent in the field of Molecular Electronics are many electrochemical concepts, including tunneling, redox exchange, activated electron transfer, and electron coupling between molecules and conducting contacts.

If holm had used a Scanning Tunneling Microscope: What the nanoscientists are teaching us about electrical contacts

“…There are a number of commercially important applications that are pushing research into the chemistry and physics of tunneling. The design of useful functions of organic electronics [107,108] (rectification, amplification, and memory) depends on the understanding of the transport of electrons through organic molecular layers [109] that are chemically or physically bonded to metal surfaces [110][111][112].…”

“…It could also be hypothesized, but presently unconfirmed, that solid-like organic films have a lower resistance than random unorganized films. The most common general model of metal/insulator/metal junctions was developed by Simmons [113][114][115][116] and is shown in a greatly simplified version in [109] allowing a clear assessment of the impact of variables:…”

Carbon Electrodes in Molecular Electronics

“…Molecular electronics is broadly defined as the study of charge transport involving molecular entities [1][2][3][4][5][6][7][8][9]. However, such a broad definition overlaps with several other related areas, including, electrochemistry [6], organic electronics [10][11][12], and donor-acceptor electron transfer studies [13,14].…”

“…However, such a broad definition overlaps with several other related areas, including, electrochemistry [6], organic electronics [10][11][12], and donor-acceptor electron transfer studies [13,14]. Indeed, insights from all of these areas have been important to advances in understanding molecular electronic systems.…”

Chemically Modified Metal Oxide Nanostructures Electrodes for Sensing and Energy Conversion

“…31 In addition to that, modification on the electrode surface may have fundamental demands that include selectivity and/or electron-transfer creation or catalysis of slow electrode reactions. 32 Therefore, CMEs have been used in several applications such as electroanalysis, 33 molecular electronics, 34 electrochromic display devices, 35 chemical sensing 36 and solar energy conversion. 37 The sensor electrode size requirements make the CMEs a highly desirable option 23 that is being intensely pursued since 1940s.…”