Performance evaluation of thin-film solar concentrators for greenhouse applications

Fluorescent Poly (methylmethacrylate) films embedded with a commercial coumarin dyestuff (MACROLEX Fluorescent Red G) were prepared by flow-spin coating technique. The absorption and emission spectra were recorded in order to determine the dye concentrations corresponding to the maximum fluorescence intensity and red shift. The emission band was optimized to match to the absorption band of chlorophylls (650–680 nm), which is the most important wavelength band for the photosynthesis process in plants. These films showed a remarkable stability against both photo and thermal degradation, pointing to their excellent weathering durability for using as photoselective films in greenhouse applications.

The film of concentration 100 ppm showed the closest emission band to the action spectra of photosynthesis in higher plants with a high transmission of red light (97.65%) and a remarkable photoresponse towards UV–VIS solar radiation. More efforts to increase the effective transmission of red light and the stability of the films are in Fluorescence intensity (normalized) the facilities needed for the measurements of the samples under investigation.