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Résumé:

During 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 (EuCl36H2O) 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.