Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/198642

Title

Effects of surface chemical composition on the early growth stages of α-sexithienyl films on silicon oxide substrates

Author(s)

Dinelli, Franco;  Moulin, Jean-François;  Loi, Maria Antonietta;  Como, Enrico Da;  Massi, Massimiliano;  Murgia, Mauro;  Muccini, Michele;  Biscarini, Fabio;  Wie, Jiang;  Kingshott, Peter

Abstract

In organic field effect transistors, charge transport is confined to a narrow region next to the organic/dielectric interface. It is thus extremely important to determine the morphology and the molecular arrangement of the organic films at their early growth stages. On a substrate of technological interest, such as thermally grown silicon oxide, it has been recently found that α-sexithienyl aggregates made of flat-lying molecules can simultaneously nucleate besides islands made of molecules standing vertical. In this paper, we investigate the effects due to variations in surface chemical composition on α-sexithienyl ultrathin film formation. Flat-lying molecules are no longer detected when Si−OH groups present at the surface are chemically removed but also when the Si−OH or Si−H group density is maximized. This gives evidence that variations in the surface chemical composition can largely affect the nucleation and growth processes of organic/dielectric interfaces. We hypothesize that isolated OH groups can interact with α-sexithienyl molecules and anchor them down flat with respect to the surface.

Publication type

Journal article

Source

Journal of Physical Chemistry B, Vol. 110, no. 1 (Jan 2006), pp. 258-263

Publication year

2006

FOR Code(s)

0306 Physical Chemistry (Incl. Structural);  0904 Chemical Engineering

Keyword(s)

Field effect transistors;  Film growth;  Flat-lying molecules;  Organic films;  Silicon;  Surface chemistry;  Ultrathin film formation

Publisher

American Chemical Society

ISSN

1520-6106

Publisher URL

http://dx.doi.org/10.1021/jp053814g

Copyright

Copyright © 2006 American Chemical Society.

Peer reviewed