Molecular rectification with M|(D-σ-A LB film)|M junctions

Abstract

Molecular materials of the form electron donor-sigma-bridge-electron acceptor (D-s-A) have been synthesized and incorporated into non-centrosymmetric Langmuir-Blodgett (LB) multilayer structures. Electrical characterization has been performed using a metal|(Z-type LB film)|metal (M|LB|M ) junction construction. Current density-voltage data demonstrate striking rectification behaviour. Computational modelling of the electronic structure of the material has been carried out using a first principles, density functional approach. Possible conduction mechanisms are discussed with reference to the results of this modelling.

Electron transfer studies through mixed self-assembled monolayers of thiophenol and thioctic acid

“…In recent years, a lot of work is being done towards molecular electronics such as wires [19,20], gates [21,22] and rectifiers [23,24] using single molecules [25,26] to organized monolayer [27]. The concept of rectification introduced by Aviram and Ratner [28] was based on asymmetric electron tunneling.…”

Monolayer Rectifiers

“…An unsymmetrical STM tunneling current was measured through an alkylated hexabenzocoronene deposited on graphite (100), and through an oligo(phenylethynyl)benzenethiol (130). Recently, two new multilayer rectifiers have been studied (131,132).…”

Materials Research Society Symposium Proceedings Volume 582. Molecular Electronics. Symposium held November 29-December 2, 1999, Boston, Massachusetts, U.S.A.

“…Another zwitterionic molecule, whose dipole moment was in the plane of the monolayer, instead of normal to it, and which did not exhibit hypsochromism, did not rectify [29]. Another molecule with an unpromising structure did, however, rectify [30].…”

“…Electronic measurements were performed in a nanostructure consisting of top metal contact (Au) -self-assembled monolayer (SAM) active region (30 diameter) -bottom metal contact (Au), similar to that reported previously [6,7]. The active electronic component was made from 2'-amino-4^thynylphenyl4'-ethynylpnenyl-5'-nitro-l-(thioacetyI)benzene (la)that was prepared as outlined in Figure 1.…”