Skip to Main content Skip to Navigation
Theses

Interface silicium/couche organique: Maitrise des propriétés et fonctionnalisation

Damien Aureau
Abstract : Organic layers covalently grafted onto silicon surfaces are promising as model systems for fundamental research and applications: ultra thin layers, chemical or biochemical sensors. This work makes use of different characterization techniques for studying these systems. The influence of the system preparation on these various characteristics is examined. Surface morphology is controlled by AFM microscopy. Chemical and electrical stability of the interface are investigated ex situ and in situ in contact with an electrolyte by photoluminescence, surface photovoltage, Mott-Schottky measurements and infrared spectroscopy in ATR Mode. Si-alkyl surfaces exhibit the same quality as Si-H surfaces with a higher stability, even in contact with buffer solutions up to pH 11. The effect of charges adsorbed at the surface has also been explored by a quantitative titration of grafted carboxyl-terminated monolayers. This titration shows that ionization of the carboxyl groups on surfaces starts around pH 6 and extends over more than 6 pH units: Observations are consistently accounted for by a model taking into account change in ion solvation at the surface and electrostatic interactions between surface charges. An original method of functionalization of dense alkyl layers by treatment in oxidising plasma is presented. The characterization, in situ by infrared spectroscopy and ex situ by X-ray photoelectron spectroscopy, and the composition of the oxygen plasma give an evidence for the etching of the layers at the highest power and integrity of those at low power: a mechanism of chain functionalization is proposed.
Complete list of metadatas

Cited literature [123 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/pastel-00004611
Contributor : Ecole Polytechnique <>
Submitted on : Monday, July 20, 2009 - 8:00:00 AM
Last modification on : Monday, July 20, 2009 - 8:00:00 AM
Long-term archiving on: : Friday, September 10, 2010 - 1:01:09 PM

Identifiers

  • HAL Id : pastel-00004611, version 1

Collections

Citation

Damien Aureau. Interface silicium/couche organique: Maitrise des propriétés et fonctionnalisation. Engineering Sciences [physics]. Ecole Polytechnique X, 2008. English. ⟨pastel-00004611⟩

Share

Metrics

Record views

362

Files downloads

6208