AVS 52nd International Symposium
    Surface Science Wednesday Sessions
       Session SS+EM-WeM

Paper SS+EM-WeM8
Alkylidyne Self-Assembled Monolayers on Pt(111): A Novel System for Molecular Electronics Applications

Wednesday, November 2, 2005, 10:40 am, Room 202

Session: Self-Assembled Monolayers
Presenter: M. Yang, Naval Research Laboratory
Authors: M. Yang, Naval Research Laboratory
A.R. Laracuente, Naval Research Laboratory
L.J. Whitman, Naval Research Laboratory
Correspondent: Click to Email
Although many alkanethiols form well-understood self-assembled monolayers (SAMs) on gold, such systems are of limited utility for molecular electronics applications given the incompatibility of gold with conventional silicon devices. Moreover, it is now widely recognized that the gold-sulfur bond inhibits electrical transport between the substrate and the bound organic molecules. Because of these issues, there has been recent interest in more compatible metals such as Pd and Pt, along with non-thiol bonding schemes for organic molecules. We are developing a new type of SAM/metal system based on direct carbon-to-metal bonding. When 1-hexene (C@sub6@H@sub14@) is vapor-deposited on clean Pt(111) in ultra-high vacuum, it converts into hexylidyne (C@sub6@H@sub11@) to form a self-assembled monolayer (SAM) with an upright geometry. Scanning tunneling microscopy studies show that the hexylidyne SAM on Pt(111) is a commensurate (3x3) overlayer. We have also investigated the influences of pressure, temperature, and coadsorbed hydrogen on the formation of the alkylidyne SAMs. Given that many of the organic molecules of potential use for current transport are alkanes and perylenes, direct carbon-metal bonding may provide the most desirable metal-molecule junction. Therefore, we believe this system has significant potential for developing molecular electronic devices.