Role of surface dimer dynamics in creating ordered organic-semiconductor interfaces

Robin L. Hayes, Mark Tuckerman

Research output: Contribution to journalArticle

Abstract

Understanding the chemical reaction mechanisms governing how small organic molecules attach to semiconductor surfaces can lead to new strategies for creating specific surface patterns such as single adduct monolayers. In this study, room-temperature ab initio molecular dynamics simulations of one and two 1,3-cyclohexadiene (CHD) molecule(s) reacting with the Si(100)-2x1 surface reveal that adducts form via a carbocation-mediated two-step mechanism. Dimer flipping can either promote or prevent bond formation depending on how the CHD approaches. CHDs often travel past several Si dimers before finding the proper local environment. The resulting intermediate can persist for more than 4 ps, allowing the second bond to form with any adjacent Si dimer. The additional reactive site accounts for a large portion of the discrepancy between the predicted thermodynamic and observed experimental product distribution. Surface adducts protect a 5.6 Å region, direct unbound CHD exploration, and can cause adjacent dimers to flip.

Original languageEnglish (US)
Pages (from-to)12172-12180
Number of pages9
JournalJournal of the American Chemical Society
Volume129
Issue number40
DOIs
StatePublished - Oct 10 2007

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Semiconductors
Semiconducting organic compounds
Dimers
Molecular Dynamics Simulation
Thermodynamics
Catalytic Domain
Molecules
Temperature
Molecular dynamics
Chemical reactions
Monolayers
Semiconductor materials
1,4-cyclohexadiene
Computer simulation
1,3-cyclohexadiene

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Role of surface dimer dynamics in creating ordered organic-semiconductor interfaces. / Hayes, Robin L.; Tuckerman, Mark.

In: Journal of the American Chemical Society, Vol. 129, No. 40, 10.10.2007, p. 12172-12180.

Research output: Contribution to journalArticle

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