CORDIS - EU research results

COating for SMArt GREENhouses

Project description

New greenhouse coating to enhance photosynthesis

It is the pigment called chlorophyll in green plants that makes them green. It absorbs blue and red light (the long and short wavelengths of the visible light spectrum), causing the plant to look green. This means the solar spectrum is not optimised for energy conversion. For instance, the use of standard fluorescent pigments in a coating at the top of a greenhouse means that half of the converted sunlight is emitted back to space – lowering the conversion efficiency. The EU-funded COSMAGREEN project will design a greenhouse coating that can actually increase the effective light inside in order to enhance the process of photosynthesis. Specifically, it will use coatings that have nano-antenna phosphor pairs that will help to reduce the back-emitted light.


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.


Net EU contribution
€ 196 707,84
86034 Poitiers Cedex

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Nouvelle-Aquitaine Poitou-Charentes Vienne
Activity type
Higher or Secondary Education Establishments
Total cost
€ 196 707,84