Atomic-scale X-ray structural analysis of self-assembled monolayers on silicon

J. C. Lin, J. A. Kellar, J. H. Kim, N. L. Yoder, K. H. Bevan, S. T. Nguyen, Mark C Hersam, M. J. Bedzyk

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Two related self-assembled monolayers (SAMs), 4-bromostyrene (BrSty) and 4-bromophenylacetylene (BPA), are photochemically grown from solution on to the monohydride-terminated Si(111) surface. The atomic-scale structures of the resulting SAMs are examined by X-ray standing waves (XSW), X-ray reflectivity (XRR), X-ray fluorescence, atomic-force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The coverage is 0.5 ML. The results show that in each case the molecule covalently bonds to a single Si T1 site and stands up-right with a slight molecular tilt of 17° that leaves the Br terminal end over a neighboring T4 site. The Br height is 8.5 Å (BrSty) and 8.6 Å (BPA) above the top surface Si atom. The combined XSW and XRR results rule-out two alternative bonding models predicted by DFT that have the root of the molecule bonded to two neighboring top Si surface atoms. Based on the XSW 111 and 333 coherent fractions, the BPA/Si(111) has a reduced vertical Br distribution width in comparison to BrSty. This greater rigidity in the molecular structure is correlated to a C=C bond at the root.

Original languageEnglish
Pages (from-to)33-39
Number of pages7
JournalEuropean Physical Journal: Special Topics
Volume167
Issue number1
DOIs
Publication statusPublished - 2009

Fingerprint

Self assembled monolayers
Silicon
structural analysis
Structural analysis
X rays
silicon
standing waves
x rays
Density functional theory
Atoms
Molecules
density functional theory
reflectance
vertical distribution
Rigidity
Molecular structure
Atomic force microscopy
rigidity
leaves
X ray photoelectron spectroscopy

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Materials Science(all)
  • Physical and Theoretical Chemistry

Cite this

Lin, J. C., Kellar, J. A., Kim, J. H., Yoder, N. L., Bevan, K. H., Nguyen, S. T., ... Bedzyk, M. J. (2009). Atomic-scale X-ray structural analysis of self-assembled monolayers on silicon. European Physical Journal: Special Topics, 167(1), 33-39. https://doi.org/10.1140/epjst/e2009-00933-8

Atomic-scale X-ray structural analysis of self-assembled monolayers on silicon. / Lin, J. C.; Kellar, J. A.; Kim, J. H.; Yoder, N. L.; Bevan, K. H.; Nguyen, S. T.; Hersam, Mark C; Bedzyk, M. J.

In: European Physical Journal: Special Topics, Vol. 167, No. 1, 2009, p. 33-39.

Research output: Contribution to journalArticle

Lin, JC, Kellar, JA, Kim, JH, Yoder, NL, Bevan, KH, Nguyen, ST, Hersam, MC & Bedzyk, MJ 2009, 'Atomic-scale X-ray structural analysis of self-assembled monolayers on silicon', European Physical Journal: Special Topics, vol. 167, no. 1, pp. 33-39. https://doi.org/10.1140/epjst/e2009-00933-8
Lin, J. C. ; Kellar, J. A. ; Kim, J. H. ; Yoder, N. L. ; Bevan, K. H. ; Nguyen, S. T. ; Hersam, Mark C ; Bedzyk, M. J. / Atomic-scale X-ray structural analysis of self-assembled monolayers on silicon. In: European Physical Journal: Special Topics. 2009 ; Vol. 167, No. 1. pp. 33-39.
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