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Modélisation de couches de grains luminophores : évolution de la morphologie durant le recuit de synthèse et efficacité optique

Abstract : The central part of energy-saving lamps consists of a glass tube filled with a mercury plasma and coated with a layer of phosphor grains. These micron-sized grains absorb UV radiation and emit visible light. In this thesis, two problems related to these layers are studied. In the first part, a phase-field model is developed to describe the change in the morphology of grains during annealing in presence of a flux, which is a major step during phosphor fabrication. Using this model, we have highlighted the role of surface tension and transport of material in the liquid. In the second part, we use the ray tracing method to model the optical properties of a layer of phosphor grains, which has to fulfill two seemingly contradictory goals: maximize absorption of UV and maximize the extraction of visible light. We have found that there exists an optimum for the extraction efficiency, which suggests that the loss of visible light in the lamp can be reduced by using less compact layers.
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https://pastel.archives-ouvertes.fr/pastel-00682611
Contributor : Nayely Pannier <>
Submitted on : Monday, March 26, 2012 - 1:58:04 PM
Last modification on : Wednesday, March 27, 2019 - 4:18:02 PM
Long-term archiving on: : Monday, November 26, 2012 - 12:10:09 PM

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Nayely Pannier. Modélisation de couches de grains luminophores : évolution de la morphologie durant le recuit de synthèse et efficacité optique. Science des matériaux [cond-mat.mtrl-sci]. Ecole Polytechnique X, 2011. Français. ⟨pastel-00682611⟩

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