TY - CONF A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Frenzel, Florian A1 - Weigert, Florian A1 - Andresen, Elina A1 - Grauel, Bettina A1 - Wegner, Karl David T1 - Semiconductor (SCNC) & Upconversion Nanocrystals (UCNC) – Optical Properties, Applications & Challenges N2 - Inorganic nanocrystals with linear and nonlinear luminescence in the ultraviolet, visible, near infrared and shortwave infrared like semiconductor quantum dots and spectrally shifting lanthanide-based nanophosphors have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. These nanomaterials commonly have increasingly sophisticated core/shell particle architectures with shells of different chemical composition and thickness to minimize radiationless deactivation at the particle surface that is usually the main energy loss mechanism [1]. For lanthanide-based spectral shifters, particularly for very small nanoparticles, also surface coatings are needed which protect near-surface lanthanide ions from luminescence quenching by high energy vibrators like O-H groups and prevent the disintegration of these nanoparticles under high dilution conditions. [2,3,4]. The identification of optimum particle structures requires quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield [5,6], ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods [7], Moreover, in the case of upconversion nanoparticles with a multi-photonic and hence, excitation power density (P)-dependent luminescence, quantitative luminescence studies over a broad P range are required to identify particle architectures that are best suited for applications in fluorescence assays up to fluorescence microscopy. Here, we present methods to quantify the photoluminescence of these different types of emitters in the vis/NIR/SWIR and as function of Pand demonstrate the importance of such measurements for a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments. T2 - 27th Annual Meeting of the Slovenian Chemical Society CY - Portoroz-Portorose, Slovenia DA - 21.09.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Surface chemistry KW - Single particle KW - Brightness KW - NIR KW - Synthesis KW - Semiconductur KW - Quantum dot KW - Nanocrystal KW - SWIR PY - 2021 AN - OPUS4-53723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frenzel, Florian T1 - Spectroscopic study of plasmon enhanced upconversion nanoparticles N2 - The presentation gave an overview of the topic, the aims and the task allocation of the M-ERA.NET founded project named “Nanohype”. In this project four research teams working hand in hand on computational modeling, synthesis and experimental validation to design novel metal-shelled Upconversion-NP combining plasmonic interactions. As Ph.D. student at the BAM I am responsible for the optical characterization (measurements of lifetimes, Quantum Yields and PL emissions ) of these promising novel systems. T2 - SpringSchool, UpCon2016 CY - Wrocław (Breslau), Polen DA - 25.05.2016 KW - Field Enhancement KW - Upconversion KW - Core-Shell KW - FRET KW - Plasmonic PY - 2016 AN - OPUS4-37225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frenzel, Florian T1 - Spectroscopic study of plasmon enhanced UPCON luminescence of silica-metal core-shell nanocomposites - status report N2 - The presentation focuses on the current state of the optical spectroscopic studies on plasmon enhanced upconversion luminescent processes of silica-metal core-shell nanocomposites. A general introduction of the upconversion process, the theoretical basis of plasmonic enhancement, the theoretical requirements in regard to NP architecture for plasmon enhanced UC will be outlined. The first proof-of-concept measurements show the difficulty in realization the theoretical measurement parameters in laboratory conditions and underline the need for shifting the experiments to single particle level.“ T2 - Gruppenseminar der Nanooptik an der HU Berlin, Prof. Benson, Institut für Physik, Raum 1‘404 CY - Berlin, Germany DA - 09.05.2017 KW - Upconversion KW - Pplasmon enhancement KW - Core-shell nanoparticles KW - Silca-metal nanoparticles PY - 2017 AN - OPUS4-50698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -