Hannover 2020 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 20: Ultrashort Laser Pulses and Biophotonics
Q 20.6: Talk
Tuesday, March 10, 2020, 15:15–15:30, f435
NaYF4:Yb,Er Upconversion Nanoparticles: Analysis of Energy Loss Processes — •Bettina Grauel1, Christian Homann2, Christian Würth1, Ute Resch-Genger1, and Markus Haase2 — 1Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin — 2Universität Osnabrück
Lanthanide-based upconversion nanoparticles are anti-Stokes emitters with narrow, sharp emission bands in the UV and Vis spectrum, while excited in the NIR. Their luminescence efficiency is affected by lattice defects (especially near the surface), solvent moluecules, surface ligands, and lanthanide doping concentrations, and can vary over several orders of magnitude. By using carefully-designed particles with different sizes, inert shell thicknesses, and doping concentrations, lifetimes and excitation power-dependent quantum yields are recorded and a comprehensive analysis of different energy loss channels is presented. The measurement results are underlined by simulations using a rate equation model system with a nine-level Erbium energy scheme.