Description du projet
Un nouveau revêtement de serre améliore la photosynthèse
Les plantes doivent leur couleur verte au pigment appelé chlorophylle. Il absorbe les composantes rouge et bleue de la lumière (les longueurs d’onde longues et courtes du spectre visible), et donne leur couleur verte aux feuilles. Le spectre solaire n’est donc pas optimisé pour la conversion de l’énergie. Par exemple, si on utilise des pigments fluorescents standard dans le revêtement du toit d’une serre, la moitié de la lumière solaire convertie sera alors renvoyée vers l’espace, ce qui réduit le rendement de conversion. Le projet COSMAGREEN, financé par l’UE, élaborera un revêtement de serre capable d’augmenter la quantité de lumière qui entre à l’intérieur de la structure afin d’améliorer le processus de photosynthèse. Plus précisément, il utilisera des revêtements dotés de nano-antennes avec des paires de phosphore qui contribueront à réduire la lumière réverbérée.
Objectif
Plants do not harvest the whole solar spectrum equally at the different wavelengths. They indeed reflect green, absorbs red and blue, so that we see them green. The consequence of that is that the solar spectrum is actually not optimised for energy conversion. However, incoming solar spectrum can be modified in order to shift less efficient wavelengths to more efficient one (like green to red) using fluorescent pigments or phosphors. In this way, photosynthesis efficiency can be increased. Meanwhile, when one uses standard fluorescent pigments implemented in a coating at the top of a greenhouse, half of the converted sunlight is emitted back to space due to their isotropic emission, thus lowering the conversion efficiency. To overcome this limit, we propose to use the properties of nano antennas for which it has been shown that they can change the emitting direction of pigments when they are placed in their vicinity. We will design a greenhouse coating that enhance photosynthesis by increasing the effective light inside greenhouses using coatings having nano-antenna phosphor pairs. Firstly, we will perform numerical calculations considering near field radiation and fluorescence, in order to find an optimum design in terms of antenna and phosphor size. Then, the coating will be produced in collaboration with a deposition facility using corresponding parameters from the numerical study. Finally, the actual design will be characterised using spectroscopy to determine the discrepancy between numerical and experimental study. Further actions like changing numerical solver and/or fabrication methods will be considered after a feedback from the two studies.
Champ scientifique
Programme(s)
Régime de financement
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinateur
86034 Poitiers Cedex
France