Structural characterization of alkylsilane and fluoroalkylsilane self-assembled monolayers on SiO2 by molecular dynamics simulations
Langue
en
Article de revue
Ce document a été publié dans
Journal of Physical Chemistry C. 2016, vol. 120, n° 27, p. 14652-14662
American Chemical Society
Résumé en anglais
We present molecular dynamics simulations of self-assembled monolayers (SAMs) chemisorbed on an atomically flat amorphous silicon dioxide substrate. We model two prototypical SAM-forming alkylsilanes, octadecyltrichlorosilane ...Lire la suite >
Mots clés en anglais
Amorphous silicon
Electronic properties
Molecular dynamics
Molecules
Monolayers
Silica
Silicon oxides
Substrates
View at Publisher| Export | Download | Add to List| More... Journal of Physical Chemistry C Volume 120
Issue 27
14 July 2016
Pages 14652-14662 Structural characterization of alkylsilane and fluoroalkylsilane self-assembled monolayers on SiO2 by molecular dynamics simulations (Article) Roscioni
O.M.a
Muccioli
L.abc
Mityashin
A.d
Cornil
J.e
Zannoni
C.a a Dipartimento di Chimica Industriale Toso Montanari
Università di Bologna
Bologna
Italy b Laboratoire de Chimie des Polymères Organiques
UMR 5629
Université de Bordeaux
Pessac
France c Institut des Sciences Molécularies
UMR 5255
Talence
France View additional affiliations View references (81) Abstract We present molecular dynamics simulations of self-assembled monolayers (SAMs) chemisorbed on an atomically flat amorphous silicon dioxide substrate. We model two prototypical SAM-forming alkylsilanes
octadecyltrichlorosilane (OTS) and 1H
1H
2H
2H-perfluorodecyltrichlorosilane (FDTS)
that find widespread use in organic electronic applications. Crucially
our model does not rely on an explicit bonding between the alkylsilane and the substrate
thus allowing for the spontaneous organization of molecules into regular structures
which we studied as a function of coverage. By comparing the calculated tilt angle
film thickness
and lattice parameters with experiments
we conclude that the simulated morphologies are quantitatively consistent with the experimental evidence
demonstrating the accuracy of the simulation methodology. We take advantage of the atomistic resolution of the calculations for carrying out a detailed one-to-one comparison between the structure and the electronic properties of the two SAMs. In particular
we find that OTS molecules show a coverage-dependent tilt
while FDTS molecules are always vertically oriented
regardless of the coverage. More importantly for organic electronic applications
we observe that OTS SAMs do not alter the electrostatic potential of silica
while FDTS SAMs induce a negative voltage shift which increases with coverage and saturates at about -2 V. © 2016 American Chemical Society. Indexed keywords Engineering controlled terms: Amorphous silicon
Substrates Atomistic resolution
Electrostatic potentials
Experimental evidence
Molecular dynamics simulations
Octadecyltrichlorosilane
Perfluorodecyltrichlorosilane
Simulation methodology
Structural characterization
Self assembled monolayers