Effect of Local Environment on Molecular Conduction:  Isolated Molecule versus Self-Assembled Monolayer

Abstract

Developing a fundamental understanding of molecular conduction in different device environments is essential to the advance of molecular electronics. We show through a quantitative comparison of two types of junctions with the same molecule - one based on an isolated individual molecule and the other on a self-assembled monolayer - that intrinsic differences in the conduction per molecule as large as several orders of magnitude can exist simply as a function of the presence or absence of neighboring molecules. This behavior can be understood on the basis of thermal and electrostatic effects that depend critically on the local molecular environment. These results will help to unify data obtained from disparate device structures and to provide an improved basis for designing future molecular electronic devices.

Electron Transfer Proteins as Electronic Conductors: Significance of the Metal and Its Binding Site in the Blue Cu Protein, Azurin

“…The KIE on ET reactions is expressed in the Marcus' theory mainly by solvent reorganization energy, due to H/D exchange‐caused differences in the optical dielectric constant and refractive index 23. These differences between H 2 O and D 2 O are small and only a minor inverse KIE value (≈0.9) is expected 24.…”

Molecules on Si: Electronics with Chemistry

“…His solar cell interests led to work hybrid molecular/non-molecular materials, which evolved into his other present activities, understanding electronic transport across (bio)molecules, exploring how molecules can control such transport, looking for novel science in such systems and for possible relevance to solar cells. changes in molecular energy levels upon contacting [47][48][49][50][51][52] and effects due to intermolecular interactions [21,[53][54][55] is accumulating. Such effects need to be clarified to isolate unique molecular contributions, be they purely molecular ones or due to interactions with the environment.…”

“…Reported temperature dependence of transport varies from none [55,172,174,175] to positive (i.e., thermal activation). [34,55,96] In MIM junctions, a pseudo-metallic temperature response is generally attributed to conductance via metallic filaments penetrating the monolayer.…”

Magnetoresistance of Nanoscale Molecular Devices

“…13 In recent years, a number of experimental techniques have been developed to synthesize molecular junctions and measure their conductance. [14][15][16][17][18][19][20][21][22][23][24][25] These systems are often controlled by a gate potential designed to shift conductance peaks into the low-bias regime. 15,[26][27][28][29][30][31][32] The referred questions are of fundamental nature, leading to the understanding of current-voltage relations.…”