Thèse de doctorat en Sciences et génie des matériaux
Soutenue le 05-04-2016
à Lyon , dans le cadre de École doctorale Sciences Ingénierie Santé (Saint-Etienne) , en partenariat avec Université Jean Monnet (Saint-Étienne) (Etablissement opérateur d''inscription) et de Laboratoire Hubert Curien (Saint-Etienne) (laboratoire) .
Le président du jury était Christophe Donnet.
Technologies laser pour l’élaboration de matériaux carbonés pour microsystèmes analytiques environnementaux
Technologies laser pour l’élaboration de matériaux carbonés pour microsystèmes analytiques environnementaux. Pas de résumé en français fourni
Amorphous carbon nitride (a-CzN) material has attractor much attention in research and development. Recently, it has become a more promising electrode material than conventional carbon based electrodes in electrochemical and biosensor applications. Nitrogen containing amorphous carbon (a-C:N) thin films have been synthesized by femtosecond pulsed laser deposition (fs-PLD) coupled with plasma assistance through Direct Current (DC) bias power supply. During the deposition process, various nitrogen pressures (0 to 50 Pa) and DC bias (0 to -350 V) were used in order to explore a wide range of nitrogen content into the film. The structure and chemical composition of the films have been studied by using Multi-wavelength (MW) Roman spectroscopy, electron energy-loss spectroscopy (EELS), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTBM). The surface morphology has been studied by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Increasing the nitrogen pressure or adding a DC bias induced an increase of the N content, up to 28 at.%. Nitrogen content increase induces a higher sp2 character of the film. However DC bias has been found to increase the film structmal disorder, which was detrimental to the electrochemical properties. Indeed the electrochemical measurern-ts, investigated by cyclic voltammetry (CV), demonstrated that the a-CzNfilms show better electron transfer kinetics, reversibility and excellent reproducibility than the pure a-C films. Electrochemical grafting from diazoniurn salts was successfully achieved on this film, with a surface coverage of covalently bonded molecules close to the dense packed monolayer of ferrocene