Synthèse de nanostructures d'oxyde de zinc par procédé laser

L'oxyde de zinc -- Les procédés laser -- Croissance de ZnO à partir d'une solution -- Techniques de caractérisation -- Démarche, organisation générale et cohérence des articles -- Démarche scientifique et organisation de la recherche -- Présentation des articles et cohérence avec les objectifs -- Contribution personnelle aux articles -- Statut des articles -- Aspects méthodologiques -- Choix du procédé -- Choix du laser -- Choix du substrat -- Choix des composantes de la solution -- Montage expérimental -- Fast synthesis of ANO nanostructures by laser-induced decomposition of zinc acetylacetonate

Influence of solution parameters for the fast growth of ZnO nanostructures by laser-induced chemical liquid deposition

ZnO nanorods, nanoneedles, nanoparticles and nanoballs were synthesized on fused quartz substrates upon irradiation of a droplet of methanolic zinc acetate dihydrate solution by an infrared continuous wave CO₂ laser for a few seconds. The addition of monoethanolamine and water to the solution improved the alignment of the nanorods and had a significant effect on the volume and morphology of the deposits. An increase of the zinc acetate concentration was found to lead to an increase of the thickness and area covered by the initial ZnO seed layer on which the nanostructures grew. By investigating the crystal structure of the deposits using x-ray and electron diffraction, we were able to show that the nanorods grow along the c axis with a high crystalline quality. Raman and photoluminescence spectroscopy confirmed the high-quality of the grown ZnO nanostructures. As a matter of fact, their photoluminescence spectra are dominated by an intense UV emission around 390 nm

Caractérisation raman de microfibres de carbone produites par déposition chimique en phase vapeur assistée par laser (LCVD)

Fibres de carbone déposées par LCVD -- Spectroscopie Raman du graphite -- Organisation générale des principales étapes du travail -- Pertinence de l'incorporation des articles au mémoire -- Détails expérimentaux et méthodologie -- Croissance des fibres -- Préparation des échantillons -- Spectroscopie Raman -- De la déposition à la caractérisation -- Croissance des fibres -- Caractérisation radiale par spectroscopie Raman de fibres de carbones déposées par 3D-LCVD -- Caractérisation Raman de microtiges de carbones fabriquées par laser en fonction des paramètres expérimentaux -- Problèmes lors de la déposition -- Problème lors de la spectroscopie Raman

Influence of solution parameters for the fast growth of ZnO nanostructures by laser-induced chemical liquid deposition

ABSTRACT: ZnO nanorods, nanoneedles, nanoparticles and nanoballs were synthesized on fused quartz substrates upon irradiation of a droplet of methanolic zinc acetate dihydrate solution by an infrared continuous wave CO₂ laser for a few seconds. The addition of monoethanolamine and water to the solution improved the alignment of the nanorods and had a significant effect on the volume and morphology of the deposits. An increase of the zinc acetate concentration was found to lead to an increase of the thickness and area covered by the initial ZnO seed layer on which the nanostructures grew. By investigating the crystal structure of the deposits using x-ray and electron diffraction, we were able to show that the nanorods grow along the c axis with a high crystalline quality. Raman and photoluminescence spectroscopy confirmed the high-quality of the grown ZnO nanostructures. As a matter of fact, their photoluminescence spectra are dominated by an intense UV emission around 390 nm