Abstracts
Optical spectroscopy of inorganic phosphors
Down-shifting and Up-Conversion Luminescence in Erbium(III) Complexes via Metal and Ligand Centered ExcitationYolimar Gil1, Ricardo C. de Santana2, Andréa S. S. de Camargo3, Leonnam G. Merízio4, Pablo Fuentealba5, Evgenia Spodine5
1University of Chile, Department of Inorganic and Analytical Chemistry, Chile, 2Instituto de Física/Universidade Federal de Goiás, 3Federal Institute for Materials Research and Testing (BAM)/ Friedrich-Schiller University Jena, 4Instituto de Física de São Carlos/ Universidade de São Paulo,, 5University of Chile
E-mail: yolimar.gil@ciq.uchile.cl
Since some of the scarce molecular-based Er-centered emitters reported in the literature are based on [ErN3O6] and [ErN9] coordination geometry, we explored the optical properties of two ErIII complexes, containing a hexaazamacrocyclic ligand with two- (1) or three-carbon (2) aliphatic lateral spacers, and three auxiliary isothiocyanate ligands. Luminescent properties were evaluated using ligand- and metal-centered excitation. Bluish-green and green emissions of the ErIII ion were detected upon ligand-centered excitation, demonstrating that these macrocycles act as antenna to sensitize the erbium(III) luminescence. Energy transfer mechanisms and temperature-dependent luminescence were analyzed. Besides the excitation in the ligands (Vis), the erbium-centered excitation at 980 nm (NIR) allowed the detection, in both cases, of bluish-green, green, and red up-converted emissions, and also the downshifted NIR emission. The possible mechanisms of these transitions are described and analyzed. Therefore, Vis-to-Vis (via ligand excitation), NIR-to-Vis and NIR-to-NIR emitters (upon 980 nm excitation) were achieved with these molecular systems.
Keywords: Luminescence, antenna, downshifting and up-conversion emission
Acknowledgments: YG acknowledges the financial support to the National Agency for Research and Development (ANID), FONDECYT Postdoctoral Project 3220200.