Unimolecular Electrical Rectifiers

Abstract

research with H. M. McConnell) and post-docs at Stanford (research with P. G. Simpson and M. Boudart), Metzger taught Italian at Stanford (1970− 1971) and chemistry at the University of Mississippi (1971−1986) and the University of Alabama (1986 to present), where he is Professor of Chemistry and former Tricampus Director of the Materials Science Ph.D. Program. Metzger has published 188 papers, edited three books, obtained one patent, graduated 12 Ph.D.'s and 1 M.S., directed the research of 15 undergraduates, and gave talks or spent sabbatical or other leaves in 22 countries. In 1984, he became the first Coulter Professor of Chemistry at the University of Mississippi. In 1998, he received the Blackmon-Moody award of the University of Alabama for exceptional research.

Mechanism of Rectification in Tunneling Junctions Based on Molecules with Asymmetric Potential Drops

“…Figure 4 outlines the mechanisms for the molecular rectifiers proposed by Williams 1 (SC 10 -phenyl-C 2 S, Fig. 3C) and Baranger et al 2 (SC 4 CoS, Co = cobaltocene, Fig. 3D).…”

“…By demonstrating rectification in a system with a single accessible molecular orbital, and by elucidating the mechanism of rectification in this system, we are able to resolve a long-standing dispute within the molecular electronics community: 3,4 namely, whether molecular rectification requires both a donor and an acceptor moiety (see below), or whether it can occur with a single, asymmetrically-placed, accessible molecular orbital.…”

“…3D), is significant whenever the rectifier is not under forward bias. They calculated the potential drop along the SC 4 CoS rectifier ( Fig. 3D) and found that when the HOMO does not overlap with the Fermi levels of the electrodes, the potential drops more or less uniformly along the whole length of the molecule, including both the C 4 alkyl spacer and the Co moiety (Fig.…”

“…3A). Though many investigators have reported rectification using this class of compounds, 4,13,43,48,41 the mechanism of rectification remains obscure for five reasons. i) These junctions have often incorporated electrodes of different materials, but analysis of them has not considered the difference of electrode materials as a source of rectification.…”

Transport Through a Driven Three-Site System

“…In recent years several suggestions how to set up a single electron transistor have been made [1,2,3,4]. The development of new methods to contact molecules or molecule-like systems and control the electron transport through them [5,6,7] is a major issue in the promising field of molecular electronics [8,9].…”