Luminescent coatings based on ethane tetracarboxamide containing Eu3+ and tta ligand: Application for Luminescent Solar Concentrators

International audienceDuring the past years, considerable interest has been focused on materials that exhibit potential applications as luminescent solar concentrators (LSCs). Indeed, the incorporation of trivalent lanthanide ion (Ln3+) complexes in organic-inorganic coatings enables the down-shifting of the UV radiationinto light that can be efficiently trapped inside the substrate and guided to the edges by total internal reflection where it can be efficiently collected by a solar cell [2]. In this communication, we will present two new precursors based on ethane tetracarboxamide and ethane dicarboxamide fragments P4 (Figure 1 (a)) and P2 (Figure 1 (b)), and their conversion into luminescent hybrid materials by the sol-gel process in the presence of Eu3+ salts (EuCl36H2O) and ligand 2-thienoyltrifluoracetone (tta) (Eu3+/tta molar ratio of 1:2). The organic-inorganic hybrid materials (P4(Eu3+/tta) and P2(Eu3+/tta)) were processed as free standing films by solvent casting. They display maximum emission quantum yield () values of 0.22 and 0.48, respectively, under excitation at 320 nm. In addition, P4(Eu3+/tta) was processed by spin-coating on glass substrates, yielding films (P4-F(Eu3+/tta) with controlled thickness of 75 nm. Under UV irradiation the films display a bright red emission ascribed to the intra-4f6 Eu3+ transitions, as illustrated in Figure 1(c) and a remarkable value of 0.60 under excitation at 345 nm