TY - CONF A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Hatami, Soheil A1 - Leubner, S. A1 - Gaponik, N. A1 - Eychmüller, A. T1 - Absolute spectroscopic characterization of the optical properties of semiconductor and upconversion nanocrystals in the vis and IR N2 - Nanocrystalline fluorophores like semiconductor quantum dots and rods and recently also lanthanide-based upconversion phosphors with emission in the visible (vis), near-infrared (NIR), and IR (infrared) region are increasingly being used in bioimaging studies and fluorescence assays as well as in photovoltaics and solid state lighting. The assessment and comparison of material performance as well as the development of rational design strategies for improved systems require spectroscopic tools, which enable the determination of the signal-relevant optical properties like photoluminescence quantum yields and brightness values. In the case of nonlinear fluorescence as shown by upconversion materials, such measurements must be also performed as function of excitation power density. In this work, we report on methods for the absolute determination of the photoluminescence quantum yield and brightness of fluorescent particles in dispersion and as powders based on integrating sphere spectroscopy and underline the importance of such measurements for the understanding of the photophysics of such nanocrystals. T2 - International Conference on Fundamental Processes in Semiconductor Nanocrystals (FQDots16) CY - Berlin, Germany DA - 05.09.2016 KW - Fluorescence KW - Nanoparticle KW - Semiconductor quantum dot KW - Upconversion nanocrystal KW - NIR KW - Integrating sphere spectroscopy KW - Fluorescence quantum yield KW - Method PY - 2016 AN - OPUS4-38695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Pauli, Jutta A1 - Hoffman, Katrin T1 - Instrument Calibration and Standardization of Fluorescence Measurements in the UV/vis/NIR/IR N2 - Comparison of fluorescence measurements performed on different fluorescence instruments, analyte quantification from fluorescence intensities as well as the determination of fluorescence quantum yields require instrument calibration and consideration of the wavelength-dependent instrument-specific quantities spectral photon flux reaching the sample and spectral responsivity. Here, we present guidelines and recommendations for the qualification of fluorescence instruments and introduce suitable chromophore-based reference materials. Moreover, the design concepts of the different BAM fluorescence standards are discussed. T2 - COST 2017 CY - Turku, Finland DA - 03.04.2017 KW - Fluorescence KW - Dye KW - Glass KW - Calibration KW - Fluorescence standard KW - Integrating sphere spectroscopy KW - Fluorescence quantum yield KW - Instrument qualification KW - Quality assurance KW - NIR KW - IR PY - 2017 AN - OPUS4-43174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Pauli, Jutta A1 - Hoffmann, Katrin T1 - Standardization of Flourescence Measurements in the UV/VIS/NIR/IR at BAM N2 - Photoluminescence techniques are amongst the most widely used tools in the life sciences, with new and exciting applications in medical diagnostics and molecular imaging continuously emerging. Advantages include their comparative ease of use, unique sensitivity, non-invasive character, and potential for multiplexing, remote sensing, and miniaturization. General drawbacks are, however, signals, that contain unwanted wavelength- and polarization contributions from instrument-dependent effects, which are also time-dependent due to aging of instrument-components, and difficulties to measure absolute fluorescence intensities. Moreover, scattering systems require special measurement geometries and the interest in new optical reporters with emission > 1000 nm strategies for reliable measurements in the second diagnostic for the comparison of material performance and the rational design of new fluorophores with improved properties. Here, we present strategies to versatile method-adaptable liquid and solid fluorescence standards for different fluorescence parameters. Examples are multi-emitter glasses, spectral fluorescence standards, and quantum yield standards for the UV/vis/NIR. T2 - Konsortiumtreffen Mikroskopie CY - Universität Münster, Germany DA - 20.01.2020 KW - Fluorescence standard KW - Instrument calibration KW - Integrating sphere spectroscopy KW - Fluorescence quantum yield KW - Fluorescent glasses KW - Fluorescence microscopy KW - Particle, imaging PY - 2020 AN - OPUS4-50308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -