Intervenant(s)
Soutenance de Mme Margareta Cristina BALOGH du Laboratoire de Chimie sous la direction de M. Olivier MAURY
Description générale
The objective of this thesis was to develop and study potential recyclable materials that can be suitable for the replacement of classical oxides used as phosphors in the fluorescent lamps. The strategy would be to combine the primary colors (RGB), red and green emission (Eu and Tb respectively) and a blue emitter.
In order to achieve our objective, we started from a molecular level by studying the luminescence of the lanthanide tris-dipicolinates in the solid state. The solid state properties of these species together with the spectroscopic properties led to the design of a phase diagram and gave us a first insight into their behavior. Furthermore, core/shell crystals were grown. We were also able to selectively turn on/off the luminescence of the core or the shell or highlight the luminescence of both emitting layers under specific excitation with UV light.
A second part of the thesis included the study lanthanide complexes inside a silica material. A first study showed an important increase in the lifetime and therefore luminance of the lanthanide embedded material. A lot of effort was then put into understanding this effect leading to a thorough characterization of the material. Since the main objective was to make white light emitting materials, a blue emitting component was also necessary. In consequence, several organic compounds were studied and synthesized to choose in the end a naphthalimide derivate.
Recyclability of the materials was also a condition established at the beginning of the thesis, therefore experiments were carried out showing that the lanthanide can be recovered.
This last study confirmed that the targeted materials have the potential of being white light emitting materials however more studies should be conducted if an industrial application is envisioned.
In order to achieve our objective, we started from a molecular level by studying the luminescence of the lanthanide tris-dipicolinates in the solid state. The solid state properties of these species together with the spectroscopic properties led to the design of a phase diagram and gave us a first insight into their behavior. Furthermore, core/shell crystals were grown. We were also able to selectively turn on/off the luminescence of the core or the shell or highlight the luminescence of both emitting layers under specific excitation with UV light.
A second part of the thesis included the study lanthanide complexes inside a silica material. A first study showed an important increase in the lifetime and therefore luminance of the lanthanide embedded material. A lot of effort was then put into understanding this effect leading to a thorough characterization of the material. Since the main objective was to make white light emitting materials, a blue emitting component was also necessary. In consequence, several organic compounds were studied and synthesized to choose in the end a naphthalimide derivate.
Recyclability of the materials was also a condition established at the beginning of the thesis, therefore experiments were carried out showing that the lanthanide can be recovered.
This last study confirmed that the targeted materials have the potential of being white light emitting materials however more studies should be conducted if an industrial application is envisioned.
Complément
Amphi Schrödinger - ENS de Lyon
Disciplines