Eu 3+ -Based Bridged Silsesquioxanes for Transparent Luminescent Solar Concentrators
Résumé
The sol−gel preparation of a bridged silsesquioxane containing
europium(III) salts and 2-thenoyltrifluoroacetone has been achieved from a new
ethane tetracarboxamide-based organosilane. Free-standing films with thicknesses
up to 440 μm and maximum absolute quantum yield (q) of 0.34 ± 0.03
(excitation at 320 nm) were prepared by the drop cast method, while thin films
(∼200−400 nm) spin-coated on glass substrates led to highly luminescent
coatings with q = 0.60 ± 0.02 (excitation at 345 nm). The thin films were tested
as planar luminescent solar concentrators and the optimized device displays an
optical conversion efficiency of 12.3% in the absorbing spectral region of the
active layer (300−380 nm).