Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Fermi Level Alignment in Self-Assembled Molecular Layers: The Effect of Coupling Chemistry

Published

Author(s)

Christopher D. Zangmeister, Steven W. Robey, Roger D. van Zee

Abstract

Photoelectron spectroscopy was used to explore changes in Fermi level alignment, within the p-p* gap, arising from changes in the coupling chemistry of conjugated phenylene ethynlene oligomers to the Au surface. Self-assembled monolayers were formed employing either thiol (4,4 -ethynylphenyl-1-benzenethiol or OPE-T) or isocyanide (4,4 -ethynylphenyl-1-benzeneisocyanide or OPE-NC) coupling. The electronic density of states in the valence region of the two systems are nearly identical with the exception of a shift to higher binding energy by about 0.5 eV for OPE-NC. Corresponding shifts in C(1s) spectra and in the threshold near Ef. The lack of change in the optical absorption suggests a rigid shift of the Fermi level within the p-p* gap is the major effect of modifying the coupling chemistry. Qualitative consideration of bonding in each case is used to suggest the influence of chemisorption-induced charge transfer as a potential explanation. Connections to other theoretical and experimental work on varying coupling chemistries in molecular layers are discussed.
Citation
Journal of Physical Chemistry B
Volume
110
Issue
34

Keywords

band line-up, monolayer, photoemission

Citation

Zangmeister, C. , Robey, S. and van, R. (2006), Fermi Level Alignment in Self-Assembled Molecular Layers: The Effect of Coupling Chemistry, Journal of Physical Chemistry B (Accessed December 7, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created August 1, 2006, Updated February 19, 2017