Luminescent Greenhouse Coatings
The quest for more light transmission
Because 1% more sunlight is 1% more crop yield, there is a long history of getting more light transmitted into the greenhouse. First low Fe2O3 glass was introduced raising transmission to typically 92%. Next, glass with an affordable AR layer was able to increase transmission by another 3%. Using thinner glass has again increased transmission but only incrementally.
A next big step is to convert the UV part of the solar spectrum to visible light using a luminescent coating. Such so-called UV2PAR coatings can raise transmission above 100% !
Removable luminescent Eu2+ doped SiAlON nano particle based UV2PAR coatings might do the trick. UV absorption depending on particle density, particle diameter, Eu concentration and layer thickness must be maximized without loosing high hemispherical light transmission and without affecting the desired horti-scatter properties of the coating. We are working on particle synthesis, light scattering and emission measurements and Monte-Carlo photon tracking calculation to reach above 100% transmission.